Merge GH #1454 Used shared_ptr repr for DL_Group

19 files changed, 845 insertions, 912 deletions

diff --git a/src/lib/math/bigint/big_ops3.cpp b/src/lib/math/bigint/big_ops3.cpp
index 48d84c8b4..eed8a29a0 100644
--- a/src/lib/math/bigint/big_ops3.cpp
+++ b/src/lib/math/bigint/big_ops3.cpp
@@ -107,6 +107,9 @@ BigInt operator*(const BigInt& x, const BigInt& y)
 */
 BigInt operator/(const BigInt& x, const BigInt& y)
    {
+   if(y.sig_words() == 1 && is_power_of_2(y.word_at(0)))
+      return (x >> (y.bits() - 1));
+
    BigInt q, r;
    divide(x, y, q, r);
    return q;
@@ -137,6 +140,9 @@ word operator%(const BigInt& n, word mod)
    if(mod == 0)
       throw BigInt::DivideByZero();
 
+   if(mod == 1)
+      return 0;
+
    if(is_power_of_2(mod))
       return (n.word_at(0) & (mod - 1));
 
diff --git a/src/lib/math/numbertheory/def_powm.h b/src/lib/math/numbertheory/def_powm.h
index 826ffb49f..fe705bf96 100644
--- a/src/lib/math/numbertheory/def_powm.h
+++ b/src/lib/math/numbertheory/def_powm.h
@@ -36,6 +36,8 @@ class Fixed_Window_Exponentiator final : public Modular_Exponentiator
       Power_Mod::Usage_Hints m_hints;
    };
 
+class Montgomery_Exponentation_State;
+
 /**
 * Montgomery Exponentiator
 */
@@ -51,12 +53,11 @@ class Montgomery_Exponentiator final : public Modular_Exponentiator
 
       Montgomery_Exponentiator(const BigInt&, Power_Mod::Usage_Hints);
    private:
-      BigInt m_exp, m_modulus, m_R_mod, m_R2_mod;
-      Modular_Reducer m_reducer;
-      word m_mod_prime;
-      size_t m_mod_words, m_exp_bits, m_window_bits;
+      std::shared_ptr<const Montgomery_Exponentation_State> m_monty;
+      BigInt m_p;
+      Modular_Reducer m_mod_p;
+      BigInt m_e;
       Power_Mod::Usage_Hints m_hints;
-      std::vector<BigInt> m_g;
    };
 
 }
diff --git a/src/lib/math/numbertheory/info.txt b/src/lib/math/numbertheory/info.txt
index 0a386b9f3..01adb7345 100644
--- a/src/lib/math/numbertheory/info.txt
+++ b/src/lib/math/numbertheory/info.txt
@@ -12,6 +12,7 @@ reducer.h
 
 <header:internal>
 def_powm.h
+monty_exp.h
 </header:internal>
 
 <requires>
diff --git a/src/lib/math/numbertheory/monty_exp.cpp b/src/lib/math/numbertheory/monty_exp.cpp
new file mode 100644
index 000000000..35d4cd668
--- /dev/null
+++ b/src/lib/math/numbertheory/monty_exp.cpp
@@ -0,0 +1,153 @@
+/*
+* Montgomery Exponentiation
+* (C) 1999-2010,2012,2018 Jack Lloyd
+*     2016 Matthias Gierlings
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/internal/monty_exp.h>
+#include <botan/numthry.h>
+#include <botan/reducer.h>
+#include <botan/internal/mp_core.h>
+
+namespace Botan {
+
+class Montgomery_Exponentation_State
+   {
+   public:
+      Montgomery_Exponentation_State(const BigInt& g,
+                                     const BigInt& p,
+                                     const Modular_Reducer& mod_p,
+                                     size_t window_bits);
+
+      BigInt exponentiation(const BigInt& k) const;
+   private:
+      BigInt m_p;
+      BigInt m_R_mod;
+      BigInt m_R2_mod;
+      word m_mod_prime;
+      size_t m_p_words;
+      size_t m_window_bits;
+      std::vector<BigInt> m_g;
+   };
+
+Montgomery_Exponentation_State::Montgomery_Exponentation_State(const BigInt& g,
+                                                               const BigInt& p,
+                                                               const Modular_Reducer& mod_p,
+                                                               size_t window_bits) :
+   m_p(p),
+   m_p_words(p.sig_words()),
+   m_window_bits(window_bits)
+   {
+   if(p.is_positive() == false || p.is_even())
+      throw Invalid_Argument("Cannot use Montgomery reduction on even or negative integer");
+
+   if(window_bits > 12) // really even 8 is too large ...
+      throw Invalid_Argument("Montgomery window bits too large");
+
+   m_mod_prime = monty_inverse(m_p.word_at(0));
+
+   const BigInt r = BigInt::power_of_2(m_p_words * BOTAN_MP_WORD_BITS);
+   m_R_mod = mod_p.reduce(r);
+   m_R2_mod = mod_p.square(m_R_mod);
+
+   m_g.resize(1U << m_window_bits);
+
+   BigInt z(BigInt::Positive, 2 * (m_p_words + 1));
+   secure_vector<word> workspace(z.size());
+
+   m_g[0] = 1;
+
+   bigint_monty_mul(z, m_g[0], m_R2_mod,
+                    m_p.data(), m_p_words, m_mod_prime,
+                    workspace.data());
+   m_g[0] = z;
+
+   m_g[1] = mod_p.reduce(g);
+
+   bigint_monty_mul(z, m_g[1], m_R2_mod,
+                    m_p.data(), m_p_words, m_mod_prime,
+                    workspace.data());
+
+   m_g[1] = z;
+
+   const BigInt& x = m_g[1];
+
+   for(size_t i = 2; i != m_g.size(); ++i)
+      {
+      const BigInt& y = m_g[i-1];
+
+      bigint_monty_mul(z, x, y, m_p.data(), m_p_words, m_mod_prime,
+                       workspace.data());
+
+      m_g[i] = z;
+      m_g[i].shrink_to_fit();
+      m_g[i].grow_to(m_p_words);
+      }
+   }
+
+BigInt Montgomery_Exponentation_State::exponentiation(const BigInt& k) const
+   {
+   const size_t exp_nibbles = (k.bits() + m_window_bits - 1) / m_window_bits;
+
+   BigInt x = m_R_mod;
+
+   const size_t z_size = 2*(m_p_words + 1);
+
+   BigInt z(BigInt::Positive, z_size);
+   secure_vector<word> workspace(z.size());
+   secure_vector<word> e(m_p_words);
+
+   for(size_t i = exp_nibbles; i > 0; --i)
+      {
+      for(size_t j = 0; j != m_window_bits; ++j)
+         {
+         bigint_monty_sqr(z, x, m_p.data(), m_p_words, m_mod_prime,
+                          workspace.data());
+
+         x = z;
+         }
+
+      const uint32_t nibble = k.get_substring(m_window_bits*(i-1), m_window_bits);
+
+      BigInt::const_time_lookup(e, m_g, nibble);
+
+      bigint_mul(z.mutable_data(), z.size(),
+                 x.data(), x.size(), x.sig_words(),
+                 e.data(), m_p_words, m_p_words,
+                 workspace.data());
+
+      bigint_monty_redc(z.mutable_data(),
+                        m_p.data(), m_p_words, m_mod_prime,
+                        workspace.data());
+
+      x = z;
+      }
+
+   x.grow_to(2*m_p_words + 1);
+
+   bigint_monty_redc(x.mutable_data(),
+                     m_p.data(), m_p_words, m_mod_prime,
+                     workspace.data());
+
+   return x;
+   }
+
+std::shared_ptr<const Montgomery_Exponentation_State>
+monty_precompute(const BigInt& g,
+                 const BigInt& p,
+                 const Modular_Reducer& mod_p,
+                 size_t window_bits)
+   {
+   return std::make_shared<const Montgomery_Exponentation_State>(g, p, mod_p, window_bits);
+   }
+
+BigInt monty_execute(const Montgomery_Exponentation_State& precomputed_state,
+                     const BigInt& k)
+   {
+   return precomputed_state.exponentiation(k);
+   }
+
+}
+
diff --git a/src/lib/math/numbertheory/monty_exp.h b/src/lib/math/numbertheory/monty_exp.h
new file mode 100644
index 000000000..65fc9ce4b
--- /dev/null
+++ b/src/lib/math/numbertheory/monty_exp.h
@@ -0,0 +1,36 @@
+/*
+* (C) 2018 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_MONTY_EXP_H_
+#define BOTAN_MONTY_EXP_H_
+
+#include <memory>
+
+namespace Botan {
+
+class BigInt;
+class Modular_Reducer;
+
+class Montgomery_Exponentation_State;
+
+/*
+* Precompute for calculating values g^x mod p
+*/
+std::shared_ptr<const Montgomery_Exponentation_State>
+monty_precompute(const BigInt& g,
+                 const BigInt& p,
+                 const Modular_Reducer& mod_p,
+                 size_t window_bits);
+
+/*
+* Return g^x mod p
+*/
+BigInt monty_execute(const Montgomery_Exponentation_State& precomputed_state,
+                     const BigInt& k);
+
+}
+
+#endif
diff --git a/src/lib/math/numbertheory/numthry.cpp b/src/lib/math/numbertheory/numthry.cpp
index 12ac51953..e80ae43ab 100644
--- a/src/lib/math/numbertheory/numthry.cpp
+++ b/src/lib/math/numbertheory/numthry.cpp
@@ -473,15 +473,15 @@ bool is_prime(const BigInt& n, RandomNumberGenerator& rng,
    const BigInt n_minus_1 = n - 1;
    const size_t s = low_zero_bits(n_minus_1);
 
-   Fixed_Exponent_Power_Mod pow_mod(n_minus_1 >> s, n);
-   Modular_Reducer reducer(n);
+   const Modular_Reducer mod_n(n);
+   const Fixed_Exponent_Power_Mod pow_mod(n_minus_1 >> s, n);
 
    for(size_t i = 0; i != test_iterations; ++i)
       {
       const BigInt a = BigInt::random_integer(rng, 2, n_minus_1);
       BigInt y = pow_mod(a);
 
-      if(mr_witness(std::move(y), reducer, n_minus_1, s))
+      if(mr_witness(std::move(y), mod_n, n_minus_1, s))
          return false;
       }
 
diff --git a/src/lib/math/numbertheory/powm_mnt.cpp b/src/lib/math/numbertheory/powm_mnt.cpp
index d3b5805e4..81102188b 100644
--- a/src/lib/math/numbertheory/powm_mnt.cpp
+++ b/src/lib/math/numbertheory/powm_mnt.cpp
@@ -1,6 +1,6 @@
 /*
 * Montgomery Exponentiation
-* (C) 1999-2010,2012 Jack Lloyd
+* (C) 1999-2010,2012,2018 Jack Lloyd
 *     2016 Matthias Gierlings
 *
 * Botan is released under the Simplified BSD License (see license.txt)
@@ -9,131 +9,32 @@
 #include <botan/internal/def_powm.h>
 #include <botan/numthry.h>
 #include <botan/internal/mp_core.h>
+#include <botan/internal/monty_exp.h>
 
 namespace Botan {
 
-/*
-* Set the exponent
-*/
 void Montgomery_Exponentiator::set_exponent(const BigInt& exp)
    {
-   m_exp = exp;
-   m_exp_bits = exp.bits();
+   m_e = exp;
    }
 
-/*
-* Set the base
-*/
 void Montgomery_Exponentiator::set_base(const BigInt& base)
    {
-   m_window_bits = Power_Mod::window_bits(m_exp.bits(), base.bits(), m_hints);
-
-   m_g.resize(1U << m_window_bits);
-
-   BigInt z(BigInt::Positive, 2 * (m_mod_words + 1));
-   secure_vector<word> workspace(z.size());
-
-   m_g[0] = 1;
-
-   bigint_monty_mul(z, m_g[0], m_R2_mod,
-                    m_modulus.data(), m_mod_words, m_mod_prime,
-                    workspace.data());
-   m_g[0] = z;
-
-   m_g[1] = m_reducer.reduce(base);
-
-   bigint_monty_mul(z, m_g[1], m_R2_mod,
-                    m_modulus.data(), m_mod_words, m_mod_prime,
-                    workspace.data());
-
-   m_g[1] = z;
-
-   const BigInt& x = m_g[1];
-
-   for(size_t i = 2; i != m_g.size(); ++i)
-      {
-      const BigInt& y = m_g[i-1];
-
-      bigint_monty_mul(z, x, y, m_modulus.data(), m_mod_words, m_mod_prime,
-                       workspace.data());
-
-      m_g[i] = z;
-      m_g[i].shrink_to_fit();
-      m_g[i].grow_to(m_mod_words);
-      }
+   size_t window_bits = Power_Mod::window_bits(m_e.bits(), base.bits(), m_hints);
+   m_monty = monty_precompute(base, m_p, m_mod_p, window_bits);
    }
 
-/*
-* Compute the result
-*/
 BigInt Montgomery_Exponentiator::execute() const
    {
-   const size_t exp_nibbles = (m_exp_bits + m_window_bits - 1) / m_window_bits;
-
-   BigInt x = m_R_mod;
-
-   const size_t z_size = 2*(m_mod_words + 1);
-
-   BigInt z(BigInt::Positive, z_size);
-   secure_vector<word> workspace(z.size());
-   secure_vector<word> e(m_mod_words);
-
-   for(size_t i = exp_nibbles; i > 0; --i)
-      {
-      for(size_t k = 0; k != m_window_bits; ++k)
-         {
-         bigint_monty_sqr(z, x, m_modulus.data(), m_mod_words, m_mod_prime,
-                          workspace.data());
-
-         x = z;
-         }
-
-      const uint32_t nibble = m_exp.get_substring(m_window_bits*(i-1), m_window_bits);
-
-      BigInt::const_time_lookup(e, m_g, nibble);
-
-      bigint_mul(z.mutable_data(), z.size(),
-                 x.data(), x.size(), x.sig_words(),
-                 e.data(), m_mod_words, m_mod_words,
-                 workspace.data());
-
-      bigint_monty_redc(z.mutable_data(),
-                        m_modulus.data(), m_mod_words, m_mod_prime,
-                        workspace.data());
-
-      x = z;
-      }
-
-   x.grow_to(2*m_mod_words + 1);
-
-   bigint_monty_redc(x.mutable_data(),
-                     m_modulus.data(), m_mod_words, m_mod_prime,
-                     workspace.data());
-
-   return x;
+   return monty_execute(*m_monty, m_e);
    }
 
-/*
-* Montgomery_Exponentiator Constructor
-*/
 Montgomery_Exponentiator::Montgomery_Exponentiator(const BigInt& mod,
                                                    Power_Mod::Usage_Hints hints) :
-   m_modulus(mod),
-   m_reducer(m_modulus),
-   m_mod_words(m_modulus.sig_words()),
-   m_window_bits(1),
+   m_p(mod),
+   m_mod_p(mod),
    m_hints(hints)
    {
-   // Montgomery reduction only works for positive odd moduli
-   if(!m_modulus.is_positive() || m_modulus.is_even())
-      throw Invalid_Argument("Montgomery_Exponentiator: invalid modulus");
-
-   m_mod_prime = monty_inverse(mod.word_at(0));
-
-   const BigInt r = BigInt::power_of_2(m_mod_words * BOTAN_MP_WORD_BITS);
-   m_R_mod = m_reducer.reduce(r);
-   m_R2_mod = m_reducer.square(m_R_mod);
-   m_exp_bits = 0;
    }
 
 }
diff --git a/src/lib/misc/srp6/srp6.cpp b/src/lib/misc/srp6/srp6.cpp
index e41c67c81..213fdc533 100644
--- a/src/lib/misc/srp6/srp6.cpp
+++ b/src/lib/misc/srp6/srp6.cpp
@@ -86,24 +86,24 @@ srp6_client_agree(const std::string& identifier,
    const BigInt& g = group.get_g();
    const BigInt& p = group.get_p();
 
-   const size_t p_bytes = group.get_p().bytes();
+   const size_t p_bytes = group.p_bytes();
 
    if(B <= 0 || B >= p)
       throw Exception("Invalid SRP parameter from server");
 
-   BigInt k = hash_seq(hash_id, p_bytes, p, g);
+   const BigInt k = hash_seq(hash_id, p_bytes, p, g);
 
-   BigInt a(rng, 256);
+   const BigInt a(rng, 256);
 
-   BigInt A = power_mod(g, a, p);
+   const BigInt A = group.power_g_p(a);
 
-   BigInt u = hash_seq(hash_id, p_bytes, A, B);
+   const BigInt u = hash_seq(hash_id, p_bytes, A, B);
 
    const BigInt x = compute_x(hash_id, identifier, password, salt);
 
-   BigInt S = power_mod((B - (k * power_mod(g, x, p))) % p, (a + (u * x)), p);
+   const BigInt S = power_mod((B - (k * power_mod(g, x, p))) % p, (a + (u * x)), p);
 
-   SymmetricKey Sk(BigInt::encode_1363(S, p_bytes));
+   const SymmetricKey Sk(BigInt::encode_1363(S, p_bytes));
 
    return std::make_pair(A, Sk);
    }
@@ -117,7 +117,7 @@ BigInt generate_srp6_verifier(const std::string& identifier,
    const BigInt x = compute_x(hash_id, identifier, password, salt);
 
    DL_Group group(group_id);
-   return power_mod(group.get_g(), x, group.get_p());
+   return group.power_g_p(x);
    }
 
 BigInt SRP6_Server_Session::step1(const BigInt& v,
@@ -137,7 +137,7 @@ BigInt SRP6_Server_Session::step1(const BigInt& v,
 
    const BigInt k = hash_seq(hash_id, m_p_bytes, p, g);
 
-   m_B = (v*k + power_mod(g, m_b, p)) % p;
+   m_B = group.mod_p(v*k + group.power_g_p(m_b));;
 
    return m_B;
    }
diff --git a/src/lib/pubkey/dh/dh.cpp b/src/lib/pubkey/dh/dh.cpp
index 2a7742738..b8b09ec3f 100644
--- a/src/lib/pubkey/dh/dh.cpp
+++ b/src/lib/pubkey/dh/dh.cpp
@@ -49,9 +49,9 @@ DH_PrivateKey::DH_PrivateKey(RandomNumberGenerator& rng,
       m_x = x_arg;
       }
 
-   if(m_y == 0)
+   if(m_y.is_zero())
       {
-      m_y = power_mod(group_g(), m_x, group_p());
+      m_y = m_group.power_g_p(m_x);
       }
    }
 
@@ -62,8 +62,10 @@ DH_PrivateKey::DH_PrivateKey(const AlgorithmIdentifier& alg_id,
                              const secure_vector<uint8_t>& key_bits) :
    DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_42)
    {
-   if(m_y == 0)
-      m_y = power_mod(group_g(), m_x, group_p());
+   if(m_y.is_zero())
+      {
+      m_y = m_group.power_g_p(m_x);
+      }
    }
 
 /*
diff --git a/src/lib/pubkey/dl_algo/dl_algo.cpp b/src/lib/pubkey/dl_algo/dl_algo.cpp
index c28ccaee0..0ac6bfce5 100644
--- a/src/lib/pubkey/dl_algo/dl_algo.cpp
+++ b/src/lib/pubkey/dl_algo/dl_algo.cpp
@@ -34,12 +34,17 @@ std::vector<uint8_t> DL_Scheme_PublicKey::public_key_bits() const
    return DER_Encoder().encode(m_y).get_contents_unlocked();
    }
 
+DL_Scheme_PublicKey::DL_Scheme_PublicKey(const DL_Group& group, const BigInt& y) :
+   m_y(y),
+   m_group(group)
+   {
+   }
+
 DL_Scheme_PublicKey::DL_Scheme_PublicKey(const AlgorithmIdentifier& alg_id,
                                          const std::vector<uint8_t>& key_bits,
-                                         DL_Group::Format format)
+                                         DL_Group::Format format) :
+   m_group(alg_id.get_parameters(), format)
    {
-   m_group.BER_decode(alg_id.get_parameters(), format);
-
    BER_Decoder(key_bits).decode(m_y);
    }
 
@@ -91,7 +96,6 @@ bool DL_Scheme_PrivateKey::check_key(RandomNumberGenerator& rng,
                                      bool strong) const
    {
    const BigInt& p = group_p();
-   const BigInt& g = group_g();
 
    if(m_y < 2 || m_y >= p || m_x < 2 || m_x >= p)
       return false;
@@ -101,7 +105,7 @@ bool DL_Scheme_PrivateKey::check_key(RandomNumberGenerator& rng,
    if(!strong)
       return true;
 
-   if(m_y != power_mod(g, m_x, p))
+   if(m_y != m_group.power_g_p(m_x))
       return false;
 
    return true;
diff --git a/src/lib/pubkey/dl_algo/dl_algo.h b/src/lib/pubkey/dl_algo/dl_algo.h
index 52b38a529..af01bc217 100644
--- a/src/lib/pubkey/dl_algo/dl_algo.h
+++ b/src/lib/pubkey/dl_algo/dl_algo.h
@@ -32,6 +32,12 @@ class BOTAN_PUBLIC_API(2,0) DL_Scheme_PublicKey : public virtual Public_Key
       const DL_Group& get_domain() const { return m_group; }
 
       /**
+      * Get the DL domain parameters of this key.
+      * @return DL domain parameters of this key
+      */
+      const DL_Group& get_group() const { return m_group; }
+
+      /**
       * Get the public value y with y = g^x mod p where x is the secret key.
       */
       const BigInt& get_y() const { return m_y; }
@@ -63,6 +69,11 @@ class BOTAN_PUBLIC_API(2,0) DL_Scheme_PublicKey : public virtual Public_Key
       size_t key_length() const override;
       size_t estimated_strength() const override;
 
+      DL_Scheme_PublicKey& operator=(const DL_Scheme_PublicKey& other) = default;
+
+   protected:
+      DL_Scheme_PublicKey() = default;
+
       /**
       * Create a public key.
       * @param alg_id the X.509 algorithm identifier
@@ -73,10 +84,7 @@ class BOTAN_PUBLIC_API(2,0) DL_Scheme_PublicKey : public virtual Public_Key
                           const std::vector<uint8_t>& key_bits,
                           DL_Group::Format group_format);
 
-      DL_Scheme_PublicKey& operator=(const DL_Scheme_PublicKey& other) = default;
-
-   protected:
-      DL_Scheme_PublicKey() = default;
+      DL_Scheme_PublicKey(const DL_Group& group, const BigInt& y);
 
       /**
       * The DL public key
@@ -106,6 +114,9 @@ class BOTAN_PUBLIC_API(2,0) DL_Scheme_PrivateKey : public virtual DL_Scheme_Publ
 
       secure_vector<uint8_t> private_key_bits() const override;
 
+      DL_Scheme_PrivateKey& operator=(const DL_Scheme_PrivateKey& other) = default;
+
+   protected:
       /**
       * Create a private key.
       * @param alg_id the X.509 algorithm identifier
@@ -116,9 +127,6 @@ class BOTAN_PUBLIC_API(2,0) DL_Scheme_PrivateKey : public virtual DL_Scheme_Publ
                            const secure_vector<uint8_t>& key_bits,
                            DL_Group::Format group_format);
 
-      DL_Scheme_PrivateKey& operator=(const DL_Scheme_PrivateKey& other) = default;
-
-   protected:
       DL_Scheme_PrivateKey() = default;
 
       /**
diff --git a/src/lib/pubkey/dl_group/dl_group.cpp b/src/lib/pubkey/dl_group/dl_group.cpp
index ea47c71a1..9eedeccf3 100644
--- a/src/lib/pubkey/dl_group/dl_group.cpp
+++ b/src/lib/pubkey/dl_group/dl_group.cpp
@@ -1,40 +1,188 @@
 /*
 * Discrete Logarithm Parameters
-* (C) 1999-2008,2015 Jack Lloyd
+* (C) 1999-2008,2015,2018 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
 #include <botan/dl_group.h>
 #include <botan/numthry.h>
+#include <botan/reducer.h>
 #include <botan/der_enc.h>
 #include <botan/ber_dec.h>
 #include <botan/pem.h>
 #include <botan/workfactor.h>
+#include <botan/internal/monty_exp.h>
+#include <map>
 
 namespace Botan {
 
+class DL_Group_Data final
+   {
+   public:
+      DL_Group_Data(const BigInt& p, const BigInt& q, const BigInt& g) :
+         m_p(p), m_q(q), m_g(g),
+         m_mod_p(p),
+         m_monty(monty_precompute(m_g, m_p, m_mod_p, /*window bits=*/4)),
+         m_p_bits(p.bits())
+         {}
+
+      ~DL_Group_Data() = default;
+
+      DL_Group_Data(const DL_Group_Data& other) = delete;
+      DL_Group_Data& operator=(const DL_Group_Data& other) = delete;
+
+      const BigInt& p() const { return m_p; }
+      const BigInt& q() const { return m_q; }
+      const BigInt& g() const { return m_g; }
+
+      BigInt mod_p(const BigInt& x) const { return m_mod_p.reduce(x); }
+
+      BigInt multiply_mod_p(const BigInt& x, const BigInt& y) const
+         {
+         return m_mod_p.multiply(x, y);
+         }
+
+      size_t p_bits() const { return m_p_bits; }
+      size_t p_bytes() const { return (m_p_bits + 7) / 8; }
+
+      BigInt power_g_p(const BigInt& k) const { return monty_execute(*m_monty, k); }
+
+   private:
+      BigInt m_p;
+      BigInt m_q;
+      BigInt m_g;
+      Modular_Reducer m_mod_p;
+      std::shared_ptr<const Montgomery_Exponentation_State> m_monty;
+      size_t m_p_bits;
+   };
+
+//static
+std::shared_ptr<DL_Group_Data> DL_Group::BER_decode_DL_group(const uint8_t data[], size_t data_len, DL_Group::Format format)
+   {
+   BigInt p, q, g;
+
+   BER_Decoder decoder(data, data_len);
+   BER_Decoder ber = decoder.start_cons(SEQUENCE);
+
+   if(format == DL_Group::ANSI_X9_57)
+      {
+      ber.decode(p)
+         .decode(q)
+         .decode(g)
+         .verify_end();
+      }
+   else if(format == DL_Group::ANSI_X9_42)
+      {
+      ber.decode(p)
+         .decode(g)
+         .decode(q)
+         .discard_remaining();
+      }
+   else if(format == DL_Group::PKCS_3)
+      {
+      // q is left as zero
+      ber.decode(p)
+         .decode(g)
+         .discard_remaining();
+      }
+   else
+      throw Invalid_Argument("Unknown DL_Group encoding " + std::to_string(format));
+
+   return std::make_shared<DL_Group_Data>(p, q, g);
+   }
+
+//static
+std::shared_ptr<DL_Group_Data>
+DL_Group::load_DL_group_info(const char* p_str,
+                             const char* q_str,
+                             const char* g_str)
+   {
+   const BigInt p(p_str);
+   const BigInt q(q_str);
+   const BigInt g(g_str);
+
+   return std::make_shared<DL_Group_Data>(p, q, g);
+   }
+
+//static
+std::shared_ptr<DL_Group_Data>
+DL_Group::load_DL_group_info(const char* p_str,
+                             const char* g_str)
+   {
+   const BigInt p(p_str);
+   const BigInt q = (p - 1) / 2;
+   const BigInt g(g_str);
+
+   return std::make_shared<DL_Group_Data>(p, q, g);
+   }
+
+namespace {
+
+DL_Group::Format pem_label_to_dl_format(const std::string& label)
+   {
+   if(label == "DH PARAMETERS")
+      return DL_Group::PKCS_3;
+   else if(label == "DSA PARAMETERS")
+      return DL_Group::ANSI_X9_57;
+   else if(label == "X942 DH PARAMETERS" || label == "X9.42 DH PARAMETERS")
+      return DL_Group::ANSI_X9_42;
+   else
+      throw Decoding_Error("DL_Group: Invalid PEM label " + label);
+   }
+
+}
+
 /*
 * DL_Group Constructor
 */
-DL_Group::DL_Group()
+DL_Group::DL_Group(const std::string& str)
    {
-   m_initialized = false;
+   // Either a name or a PEM block, try name first
+   m_data = DL_group_info(str);
+
+   if(m_data == nullptr)
+      {
+      try
+         {
+         std::string label;
+         const std::vector<uint8_t> ber = unlock(PEM_Code::decode(str, label));
+         Format format = pem_label_to_dl_format(label);
+
+         m_data = BER_decode_DL_group(ber.data(), ber.size(), format);
+         }
+      catch(...) {}
+      }
+
+   if(m_data == nullptr)
+      throw Invalid_Argument("DL_Group: Unknown group " + str);
    }
 
+namespace {
+
 /*
-* DL_Group Constructor
+* Create generator of the q-sized subgroup (DSA style generator)
 */
-DL_Group::DL_Group(const std::string& name)
+BigInt make_dsa_generator(const BigInt& p, const BigInt& q)
    {
-   const std::string pem = PEM_for_named_group(name);
+   const BigInt e = (p - 1) / q;
 
-   if(pem == "")
-      throw Invalid_Argument("DL_Group: Unknown group " + name);
+   if(e == 0 || (p - 1) % q > 0)
+      throw Invalid_Argument("make_dsa_generator q does not divide p-1");
+
+   for(size_t i = 0; i != PRIME_TABLE_SIZE; ++i)
+      {
+      // TODO precompute!
+      BigInt g = power_mod(PRIMES[i], e, p);
+      if(g > 1)
+         return g;
+      }
 
-   PEM_decode(pem);
+   throw Internal_Error("DL_Group: Couldn't create a suitable generator");
    }
 
+}
+
 /*
 * DL_Group Constructor
 */
@@ -42,55 +190,63 @@ DL_Group::DL_Group(RandomNumberGenerator& rng,
                    PrimeType type, size_t pbits, size_t qbits)
    {
    if(pbits < 1024)
-      throw Invalid_Argument("DL_Group: prime size " + std::to_string(pbits) +
-                             " is too small");
+      throw Invalid_Argument("DL_Group: prime size " + std::to_string(pbits) + " is too small");
 
    if(type == Strong)
       {
-      m_p = random_safe_prime(rng, pbits);
-      m_q = (m_p - 1) / 2;
-      m_g = 2;
+      const BigInt p = random_safe_prime(rng, pbits);
+      const BigInt q = (p - 1) / 2;
 
       /*
       Always choose a generator that is quadratic reside mod p,
       this forces g to be a generator of the subgroup of size q.
       */
-      if(jacobi(m_g, m_p) != 1)
+      BigInt g = 2;
+      if(jacobi(g, p) != 1)
          {
          // prime table does not contain 2
          for(size_t i = 0; i < PRIME_TABLE_SIZE; ++i)
             {
-            m_g = PRIMES[i];
-            if(jacobi(m_g, m_p) == 1)
+            g = PRIMES[i];
+            if(jacobi(g, p) == 1)
                break;
             }
          }
+
+      m_data = std::make_shared<DL_Group_Data>(p, q, g);
       }
    else if(type == Prime_Subgroup)
       {
-      if(!qbits)
+      if(qbits == 0)
          qbits = dl_exponent_size(pbits);
 
-      m_q = random_prime(rng, qbits);
+      const BigInt q = random_prime(rng, qbits);
+      Modular_Reducer mod_2q(2*q);
       BigInt X;
-      while(m_p.bits() != pbits || !is_prime(m_p, rng))
+      BigInt p;
+      while(p.bits() != pbits || !is_prime(p, rng))
          {
          X.randomize(rng, pbits);
-         m_p = X - (X % (2*m_q) - 1);
+         p = X - mod_2q.reduce(X) + 1;
          }
 
-      m_g = make_dsa_generator(m_p, m_q);
+      const BigInt g = make_dsa_generator(p, q);
+      m_data = std::make_shared<DL_Group_Data>(p, q, g);
       }
    else if(type == DSA_Kosherizer)
       {
-      qbits = qbits ? qbits : ((pbits <= 1024) ? 160 : 256);
+      if(qbits == 0)
+         qbits = ((pbits <= 1024) ? 160 : 256);
 
-      generate_dsa_primes(rng, m_p, m_q, pbits, qbits);
-
-      m_g = make_dsa_generator(m_p, m_q);
+      BigInt p, q;
+      generate_dsa_primes(rng, p, q, pbits, qbits);
+      const BigInt g = make_dsa_generator(p, q);
+      m_data = std::make_shared<DL_Group_Data>(p, q, g);
+      }
+   else
+      {
+      throw Invalid_Argument("DL_Group unknown PrimeType");
       }
-
-   m_initialized = true;
    }
 
 /*
@@ -100,57 +256,38 @@ DL_Group::DL_Group(RandomNumberGenerator& rng,
                    const std::vector<uint8_t>& seed,
                    size_t pbits, size_t qbits)
    {
-   if(!generate_dsa_primes(rng, m_p, m_q, pbits, qbits, seed))
-      throw Invalid_Argument("DL_Group: The seed given does not "
-                             "generate a DSA group");
+   BigInt p, q;
 
-   m_g = make_dsa_generator(m_p, m_q);
+   if(!generate_dsa_primes(rng, p, q, pbits, qbits, seed))
+      throw Invalid_Argument("DL_Group: The seed given does not generate a DSA group");
 
-   m_initialized = true;
+   BigInt g = make_dsa_generator(p, q);
+
+   m_data = std::make_shared<DL_Group_Data>(p, q, g);
    }
 
 /*
 * DL_Group Constructor
 */
-DL_Group::DL_Group(const BigInt& p1, const BigInt& g1)
+DL_Group::DL_Group(const BigInt& p, const BigInt& g)
    {
-   initialize(p1, 0, g1);
+   m_data = std::make_shared<DL_Group_Data>(p, 0, g);
    }
 
 /*
 * DL_Group Constructor
 */
-DL_Group::DL_Group(const BigInt& p1, const BigInt& q1, const BigInt& g1)
+DL_Group::DL_Group(const BigInt& p, const BigInt& q, const BigInt& g)
    {
-   initialize(p1, q1, g1);
+   m_data = std::make_shared<DL_Group_Data>(p, q, g);
    }
 
-/*
-* DL_Group Initializer
-*/
-void DL_Group::initialize(const BigInt& p1, const BigInt& q1, const BigInt& g1)
+const DL_Group_Data& DL_Group::data() const
    {
-   if(p1 < 3)
-      throw Invalid_Argument("DL_Group: Prime invalid");
-   if(g1 < 2 || g1 >= p1)
-      throw Invalid_Argument("DL_Group: Generator invalid");
-   if(q1 < 0 || q1 >= p1)
-      throw Invalid_Argument("DL_Group: Subgroup invalid");
-
-   m_p = p1;
-   m_g = g1;
-   m_q = q1;
-
-   m_initialized = true;
-   }
+   if(m_data)
+      return *m_data;
 
-/*
-* Verify that the group has been set
-*/
-void DL_Group::init_check() const
-   {
-   if(!m_initialized)
-      throw Invalid_State("DLP group cannot be used uninitialized");
+   throw Invalid_State("DL_Group uninitialized");
    }
 
 /*
@@ -159,29 +296,28 @@ void DL_Group::init_check() const
 bool DL_Group::verify_group(RandomNumberGenerator& rng,
                             bool strong) const
    {
-   init_check();
-
-   if(m_g < 2 || m_p < 3 || m_q < 0)
+   if(get_g() < 2 || get_p() < 3 || get_q() < 0)
       return false;
 
    const size_t prob = (strong) ? 128 : 10;
 
-   if(m_q != 0)
+   if(get_q() != 0)
       {
-      if((m_p - 1) % m_q != 0)
+      if((get_p() - 1) % get_q() != 0)
          {
          return false;
          }
-      if(power_mod(m_g, m_q, m_p) != 1)
+      if(this->power_g_p(get_q()) != 1)
          {
          return false;
          }
-      if(!is_prime(m_q, rng, prob))
+      if(!is_prime(get_q(), rng, prob))
          {
          return false;
          }
       }
-   if(!is_prime(m_p, rng, prob))
+
+   if(!is_prime(get_p(), rng, prob))
       {
       return false;
       }
@@ -193,8 +329,7 @@ bool DL_Group::verify_group(RandomNumberGenerator& rng,
 */
 const BigInt& DL_Group::get_p() const
    {
-   init_check();
-   return m_p;
+   return data().p();
    }
 
 /*
@@ -202,8 +337,7 @@ const BigInt& DL_Group::get_p() const
 */
 const BigInt& DL_Group::get_g() const
    {
-   init_check();
-   return m_g;
+   return data().g();
    }
 
 /*
@@ -211,10 +345,38 @@ const BigInt& DL_Group::get_g() const
 */
 const BigInt& DL_Group::get_q() const
    {
-   init_check();
-   if(m_q == 0)
-      throw Invalid_State("DLP group has no q prime specified");
-   return m_q;
+   return data().q();
+   }
+
+size_t DL_Group::p_bits() const
+   {
+   return data().p_bits();
+   }
+
+size_t DL_Group::p_bytes() const
+   {
+   return data().p_bytes();
+   }
+
+BigInt DL_Group::inverse_mod_p(const BigInt& x) const
+   {
+   // precompute??
+   return inverse_mod(x, get_p());
+   }
+
+BigInt DL_Group::mod_p(const BigInt& x) const
+   {
+   return data().mod_p(x);
+   }
+
+BigInt DL_Group::multiply_mod_p(const BigInt& x, const BigInt& y) const
+   {
+   return data().multiply_mod_p(x, y);
+   }
+
+BigInt DL_Group::power_g_p(const BigInt& x) const
+   {
+   return data().power_g_p(x);
    }
 
 /*
@@ -222,18 +384,13 @@ const BigInt& DL_Group::get_q() const
 */
 std::vector<uint8_t> DL_Group::DER_encode(Format format) const
    {
-   init_check();
-
-   if((m_q == 0) && (format != PKCS_3))
-      throw Encoding_Error("The ANSI DL parameter formats require a subgroup");
-
    if(format == ANSI_X9_57)
       {
       return DER_Encoder()
          .start_cons(SEQUENCE)
-            .encode(m_p)
-            .encode(m_q)
-            .encode(m_g)
+            .encode(get_p())
+            .encode(get_q())
+            .encode(get_g())
          .end_cons()
       .get_contents_unlocked();
       }
@@ -241,9 +398,9 @@ std::vector<uint8_t> DL_Group::DER_encode(Format format) const
       {
       return DER_Encoder()
          .start_cons(SEQUENCE)
-            .encode(m_p)
-            .encode(m_g)
-            .encode(m_q)
+            .encode(get_p())
+            .encode(get_g())
+            .encode(get_q())
          .end_cons()
       .get_contents_unlocked();
       }
@@ -251,8 +408,8 @@ std::vector<uint8_t> DL_Group::DER_encode(Format format) const
       {
       return DER_Encoder()
          .start_cons(SEQUENCE)
-            .encode(m_p)
-            .encode(m_g)
+            .encode(get_p())
+            .encode(get_g())
          .end_cons()
       .get_contents_unlocked();
       }
@@ -277,41 +434,14 @@ std::string DL_Group::PEM_encode(Format format) const
       throw Invalid_Argument("Unknown DL_Group encoding " + std::to_string(format));
    }
 
-/*
-* Decode BER encoded parameters
-*/
-void DL_Group::BER_decode(const std::vector<uint8_t>& data,
-                          Format format)
+DL_Group::DL_Group(const uint8_t ber[], size_t ber_len, Format format)
    {
-   BigInt new_p, new_q, new_g;
-
-   BER_Decoder decoder(data);
-   BER_Decoder ber = decoder.start_cons(SEQUENCE);
-
-   if(format == ANSI_X9_57)
-      {
-      ber.decode(new_p)
-         .decode(new_q)
-         .decode(new_g)
-         .verify_end();
-      }
-   else if(format == ANSI_X9_42)
-      {
-      ber.decode(new_p)
-         .decode(new_g)
-         .decode(new_q)
-         .discard_remaining();
-      }
-   else if(format == PKCS_3)
-      {
-      ber.decode(new_p)
-         .decode(new_g)
-         .discard_remaining();
-      }
-   else
-      throw Invalid_Argument("Unknown DL_Group encoding " + std::to_string(format));
+   m_data = BER_decode_DL_group(ber, ber_len, format);
+   }
 
-   initialize(new_p, new_q, new_g);
+void DL_Group::BER_decode(const std::vector<uint8_t>& ber, Format format)
+   {
+   m_data = BER_decode_DL_group(ber.data(), ber.size(), format);
    }
 
 /*
@@ -320,37 +450,18 @@ void DL_Group::BER_decode(const std::vector<uint8_t>& data,
 void DL_Group::PEM_decode(const std::string& pem)
    {
    std::string label;
+   const std::vector<uint8_t> ber = unlock(PEM_Code::decode(pem, label));
+   Format format = pem_label_to_dl_format(label);
 
-   auto ber = unlock(PEM_Code::decode(pem, label));
-
-   if(label == "DH PARAMETERS")
-      BER_decode(ber, PKCS_3);
-   else if(label == "DSA PARAMETERS")
-      BER_decode(ber, ANSI_X9_57);
-   else if(label == "X942 DH PARAMETERS" || label == "X9.42 DH PARAMETERS")
-      BER_decode(ber, ANSI_X9_42);
-   else
-      throw Decoding_Error("DL_Group: Invalid PEM label " + label);
+   m_data = BER_decode_DL_group(ber.data(), ber.size(), format);
    }
 
-/*
-* Create generator of the q-sized subgroup (DSA style generator)
-*/
-BigInt DL_Group::make_dsa_generator(const BigInt& p, const BigInt& q)
+//static
+std::string DL_Group::PEM_for_named_group(const std::string& name)
    {
-   const BigInt e = (p - 1) / q;
-
-   if(e == 0 || (p - 1) % q > 0)
-      throw Invalid_Argument("make_dsa_generator q does not divide p-1");
-
-   for(size_t i = 0; i != PRIME_TABLE_SIZE; ++i)
-      {
-      BigInt g = power_mod(PRIMES[i], e, p);
-      if(g > 1)
-         return g;
-      }
-
-   throw Internal_Error("DL_Group: Couldn't create a suitable generator");
+   DL_Group group(name);
+   DL_Group::Format format = group.get_q().is_zero() ? DL_Group::PKCS_3 : DL_Group::ANSI_X9_42;
+   return group.PEM_encode(format);
    }
 
 }
diff --git a/src/lib/pubkey/dl_group/dl_group.h b/src/lib/pubkey/dl_group/dl_group.h
index 24b829bd9..2bd79e3dd 100644
--- a/src/lib/pubkey/dl_group/dl_group.h
+++ b/src/lib/pubkey/dl_group/dl_group.h
@@ -1,6 +1,6 @@
 /*
 * Discrete Logarithm Group
-* (C) 1999-2008 Jack Lloyd
+* (C) 1999-2008,2018 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -12,31 +12,20 @@
 
 namespace Botan {
 
+class DL_Group_Data;
+
 /**
-* This class represents discrete logarithm groups. It holds a prime p,
-* a prime q = (p-1)/2 and g = x^((p-1)/q) mod p.
+* This class represents discrete logarithm groups. It holds a prime
+* modulus p, a generator g, and (optionally) a prime q which is a
+* factor of (p-1). In most cases g generates the order-q subgroup.
 */
 class BOTAN_PUBLIC_API(2,0) DL_Group final
    {
    public:
-
       /**
-      * Get the prime p.
-      * @return prime p
-      */
-      const BigInt& get_p() const;
-
-      /**
-      * Get the prime q.
-      * @return prime q
-      */
-      const BigInt& get_q() const;
-
-      /**
-      * Get the base g.
-      * @return base g
+      * Determine the prime creation for DL groups.
       */
-      const BigInt& get_g() const;
+      enum PrimeType { Strong, Prime_Subgroup, DSA_Kosherizer };
 
       /**
       * The DL group encoding format variants.
@@ -53,52 +42,11 @@ class BOTAN_PUBLIC_API(2,0) DL_Group final
       };
 
       /**
-      * Determine the prime creation for DL groups.
-      */
-      enum PrimeType { Strong, Prime_Subgroup, DSA_Kosherizer };
-
-      /**
-      * Perform validity checks on the group.
-      * @param rng the rng to use
-      * @param strong whether to perform stronger by lengthier tests
-      * @return true if the object is consistent, false otherwise
-      */
-      bool verify_group(RandomNumberGenerator& rng, bool strong) const;
-
-      /**
-      * Encode this group into a string using PEM encoding.
-      * @param format the encoding format
-      * @return string holding the PEM encoded group
-      */
-      std::string PEM_encode(Format format) const;
-
-      /**
-      * Encode this group into a string using DER encoding.
-      * @param format the encoding format
-      * @return string holding the DER encoded group
-      */
-      std::vector<uint8_t> DER_encode(Format format) const;
-
-      /**
-      * Decode a DER/BER encoded group into this instance.
-      * @param ber a vector containing the DER/BER encoded group
-      * @param format the format of the encoded group
-      */
-      void BER_decode(const std::vector<uint8_t>& ber,
-                      Format format);
-
-      /**
-      * Decode a PEM encoded group into this instance.
-      * @param pem the PEM encoding of the group
-      */
-      void PEM_decode(const std::string& pem);
-
-      /**
       * Construct a DL group with uninitialized internal value.
       * Use this constructor is you wish to set the groups values
       * from a DER or PEM encoded group.
       */
-      DL_Group();
+      DL_Group() = default;
 
       /**
       * Construct a DL group that is registered in the configuration.
@@ -137,7 +85,7 @@ class BOTAN_PUBLIC_API(2,0) DL_Group final
                size_t pbits = 1024, size_t qbits = 0);
 
       /**
-      * Create a DL group. The prime q will be determined according to p.
+      * Create a DL group.
       * @param p the prime p
       * @param g the base g
       */
@@ -152,16 +100,126 @@ class BOTAN_PUBLIC_API(2,0) DL_Group final
       DL_Group(const BigInt& p, const BigInt& q, const BigInt& g);
 
       /**
+      * Decode a BER-encoded DL group param
+      */
+      DL_Group(const uint8_t ber[], size_t ber_len, Format format);
+
+      /**
+      * Decode a BER-encoded DL group param
+      */
+      template<typename Alloc>
+      DL_Group(const std::vector<uint8_t, Alloc>& ber, Format format) :
+         DL_Group(ber.data(), ber.size(), format) {}
+
+      /**
+      * Get the prime p.
+      * @return prime p
+      */
+      const BigInt& get_p() const;
+
+      /**
+      * Get the prime q, returns zero if q is not used
+      * @return prime q
+      */
+      const BigInt& get_q() const;
+
+      /**
+      * Get the base g.
+      * @return base g
+      */
+      const BigInt& get_g() const;
+
+      /**
+      * Perform validity checks on the group.
+      * @param rng the rng to use
+      * @param strong whether to perform stronger by lengthier tests
+      * @return true if the object is consistent, false otherwise
+      */
+      bool verify_group(RandomNumberGenerator& rng, bool strong) const;
+
+      /**
+      * Encode this group into a string using PEM encoding.
+      * @param format the encoding format
+      * @return string holding the PEM encoded group
+      */
+      std::string PEM_encode(Format format) const;
+
+      /**
+      * Encode this group into a string using DER encoding.
+      * @param format the encoding format
+      * @return string holding the DER encoded group
+      */
+      std::vector<uint8_t> DER_encode(Format format) const;
+
+      /*
+      * Reduce an integer modulo p
+      * @return x % p
+      */
+      BigInt mod_p(const BigInt& x) const;
+
+      /*
+      * Multiply and reduce an integer modulo p
+      * @return (x*y) % p
+      */
+      BigInt multiply_mod_p(const BigInt& x, const BigInt& y) const;
+
+      BigInt inverse_mod_p(const BigInt& x) const;
+
+      /*
+      * Modular exponentiation
+      * @return (g^x) % p
+      */
+      BigInt power_g_p(const BigInt& x) const;
+
+      /**
+      * Return the size of p in bits
+      * Same as get_p().bits()
+      */
+      size_t p_bits() const;
+
+      /**
+      * Return the size of p in bytes
+      * Same as get_p().bytes()
+      */
+      size_t p_bytes() const;
+
+      /**
+      * Decode a DER/BER encoded group into this instance.
+      * @param ber a vector containing the DER/BER encoded group
+      * @param format the format of the encoded group
+      */
+      void BER_decode(const std::vector<uint8_t>& ber, Format format);
+
+      /**
+      * Decode a PEM encoded group into this instance.
+      * @param pem the PEM encoding of the group
+      */
+      void PEM_decode(const std::string& pem);
+
+      /**
       * Return PEM representation of named DL group
       */
-      static std::string PEM_for_named_group(const std::string& name);
+      static std::string BOTAN_DEPRECATED("Use DL_Group(name).PEM_encode()")
+         PEM_for_named_group(const std::string& name);
+
+      /*
+      * For internal use only
+      */
+      static std::shared_ptr<DL_Group_Data> DL_group_info(const std::string& name);
+
    private:
-      static BigInt make_dsa_generator(const BigInt&, const BigInt&);
+      static std::shared_ptr<DL_Group_Data> load_DL_group_info(const char* p_str,
+                                                               const char* q_str,
+                                                               const char* g_str);
+
+      static std::shared_ptr<DL_Group_Data> load_DL_group_info(const char* p_str,
+                                                               const char* g_str);
+
+      static std::shared_ptr<DL_Group_Data>
+         BER_decode_DL_group(const uint8_t data[], size_t data_len, DL_Group::Format format);
 
-      void init_check() const;
-      void initialize(const BigInt&, const BigInt&, const BigInt&);
-      bool m_initialized;
-      BigInt m_p, m_q, m_g;
+      const DL_Group_Data& data() const;
+      std::shared_ptr<DL_Group_Data> m_data;
    };
 
 }
diff --git a/src/lib/pubkey/dl_group/dl_named.cpp b/src/lib/pubkey/dl_group/dl_named.cpp
index 675098406..94729d136 100644
--- a/src/lib/pubkey/dl_group/dl_named.cpp
+++ b/src/lib/pubkey/dl_group/dl_named.cpp
@@ -9,503 +9,159 @@
 
 namespace Botan {
 
-std::string DL_Group::PEM_for_named_group(const std::string& name)
+//static
+std::shared_ptr<DL_Group_Data> DL_Group::DL_group_info(const std::string& name)
    {
-   if(name == "modp/ietf/1024")
-      return
-         "-----BEGIN X942 DH PARAMETERS-----"
-         "MIIBCgKBgQD//////////8kP2qIhaMI0xMZii4DcHNEpAk4IimfMdAILvqY7E5si"
-         "UUoIeY40BN3vlRmzzTpDGzArCm3yXxQ3T+E1bW1RwkXkhbV2Yl5+xvRMQummN+1r"
-         "C/9ctvQGt+3uOGv7Womfpa6fJBF8Sx/mSShmUezmU4H//////////wIBAgKBgH//"
-         "////////5IftURC0YRpiYzFFwG4OaJSBJwRFM+Y6AQXfUx2JzZEopQQ8xxoCbvfK"
-         "jNnmnSGNmBWFNvkvihun8Jq2tqjhIvJC2rsxLz9jeiYhdNMb9rWF/65begNb9vcc"
-         "Nf2tRM/S10+SCL4lj/MklDMo9nMpwP//////////"
-         "-----END X942 DH PARAMETERS-----";
+   /* TLS FFDHE groups */
 
-   if(name == "modp/srp/1024")
-      return
-         "-----BEGIN X942 DH PARAMETERS-----"
-         "MIIBCgKBgQDurwq5rbON1pwz+Ar6j8XoYHJhh3X/PAueojFMnCVldtZ033SW6oHT"
-         "ODtIE9aSxuDg1djiULmL5I5JXB1gidrRXcfXtGFU1rbOjvStabFdSYJVmyl7zxiF"
-         "xSn1ZmYOV+xo7bw8BXJswC/Uy/SXbqqa/VE4/oN2Q1ufxh0vwOsG4wIBAgKBgHdX"
-         "hVzW2cbrThn8BX1H4vQwOTDDuv+eBc9RGKZOErK7azpvukt1QOmcHaQJ60ljcHBq"
-         "7HEoXMXyRySuDrBE7Wiu4+vaMKprW2dHela02K6kwSrNlL3njELilPqzMwcr9jR2"
-         "3h4CuTZgF+pl+ku3VU1+qJx/Qbshrc/jDpfgdYNx"
-         "-----END X942 DH PARAMETERS-----";
+   if(name == "ffdhe/ietf/2048")
+      {
+      return load_DL_group_info("0x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
+                                "0x2");
+      }
 
-   if(name == "modp/ietf/1536")
-      return
-         "-----BEGIN X942 DH PARAMETERS-----"
-         "MIIBigKBwQD//////////8kP2qIhaMI0xMZii4DcHNEpAk4IimfMdAILvqY7E5si"
-         "UUoIeY40BN3vlRmzzTpDGzArCm3yXxQ3T+E1bW1RwkXkhbV2Yl5+xvRMQummN+1r"
-         "C/9ctvQGt+3uOGv7Womfpa6fJBF8Sx/mSShmUezkWz3CAHy4oWO/BZjaSDYcVdOa"
-         "aRY/qP0kz1+DZV0j3KOtlhxi81YghVK7ntUpB3CWlm1nDDVOSryYBPF0bAjKI3Mn"
-         "//////////8CAQICgcB//////////+SH7VEQtGEaYmMxRcBuDmiUgScERTPmOgEF"
-         "31Mdic2RKKUEPMcaAm73yozZ5p0hjZgVhTb5L4obp/Catrao4SLyQtq7MS8/Y3om"
-         "IXTTG/a1hf+uW3oDW/b3HDX9rUTP0tdPkgi+JY/zJJQzKPZyLZ7hAD5cULHfgsxt"
-         "JBsOKunNNIsf1H6SZ6/Bsq6R7lHWyw4xeasQQqldz2qUg7hLSzazhhqnJV5MAni6"
-         "NgRlEbmT//////////8="
-         "-----END X942 DH PARAMETERS-----";
+   if(name == "ffdhe/ietf/3072")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
-   if(name == "modp/srp/1536")
-      return
-         "-----BEGIN DH PARAMETERS-----"
-         "MIHHAoHBAJ3vPK+5OSd6sfEqhheke7vbpR30maxMgL7uqWFLGcxNX09fVW4ny95R"
-         "xqlL5GB6KRVYkDug0PhDgLZVu5oi6NzfAop87Gfw0IE0sci5eYkUm2CeC+O6tj1H"
-         "VIOB28Wx/HZOP0tT3Z2hFYv9PiucjPVu3wGVOTSWJ9sv1T0kt8SGZXcuQ31sf4zk"
-         "QnNK98y3roN8Jkrjqb64f4ov6bi1KS5aAh//XpFHnoznoowkQsbzFRgPk0maI03P"
-         "duP+0TX5uwIBAg=="
-         "-----END DH PARAMETERS-----";
+   if(name == "ffdhe/ietf/4096")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
-   if(name == "modp/ietf/2048")
-      return
-         "-----BEGIN X942 DH PARAMETERS-----"
-         "MIICDAKCAQEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqsqmj//////////wIBAgKCAQB//////////+SH7VEQtGEa"
-         "YmMxRcBuDmiUgScERTPmOgEF31Mdic2RKKUEPMcaAm73yozZ5p0hjZgVhTb5L4ob"
-         "p/Catrao4SLyQtq7MS8/Y3omIXTTG/a1hf+uW3oDW/b3HDX9rUTP0tdPkgi+JY/z"
-         "JJQzKPZyLZ7hAD5cULHfgsxtJBsOKunNNIsf1H6SZ6/Bsq6R7lHWyw4xeasQQqld"
-         "z2qUg7hLSzazhhqnJV5MAni6NgRlDBC+GUgvIxcbZx3xzzuWDAdDAc2TwdF2A9FH"
-         "2uKu+DemKWTvFeX7SqwLjBzKpL51SrVyiukTDEx9AogKuUctRVZVNH//////////"
-         "-----END X942 DH PARAMETERS-----";
+   if(name == "ffdhe/ietf/6144")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
-   if(name == "modp/srp/2048")
-      return
-         "-----BEGIN X942 DH PARAMETERS-----"
-         "MIICDAKCAQEArGvbQTJKmpvxZt5eE4lYL69ytmUZh+4H/DGSlD21YFCjcynLtKCZ"
-         "7YGT4HV3Z6E91SMSq0sDMQ3Nf0ip2gT9UOgIOWntt2ewz2CVF5oWOrNmGgX71fqq"
-         "6CkYqZYvC5O4Vfl5k+yXXuqoDXQK2/T/dHNZ0EHVwz6nHSgeRGsUdzvKl7Q6I/uA"
-         "Fna9IHpDbGSB8dK5B4cXRhpbnTLmiPh3SFRFI7UksNV9Xqd6J3XS7PoDLPvb9S+z"
-         "eGFgJ5AE5Xrmr4dOcwPOUymczAQce8MI2CpWmPOo0MOCca41+Onb+7aUtcgD2J96"
-         "5DXeI21SX1R1m2XjcvzWjvIPpxEfnkr/cwIBAgKCAQBWNe2gmSVNTfizby8JxKwX"
-         "17lbMozD9wP+GMlKHtqwKFG5lOXaUEz2wMnwOruz0J7qkYlVpYGYhua/pFTtAn6o"
-         "dAQctPbbs9hnsEqLzQsdWbMNAv3q/VV0FIxUyxeFydwq/LzJ9kuvdVQGugVt+n+6"
-         "OazoIOrhn1OOlA8iNYo7neVL2h0R/cALO16QPSG2MkD46VyDw4ujDS3OmXNEfDuk"
-         "KiKR2pJYar6vU70Tuul2fQGWfe36l9m8MLATyAJyvXNXw6c5gecplM5mAg494YRs"
-         "FStMedRoYcE41xr8dO3920pa5AHsT71yGu8RtqkvqjrNsvG5fmtHeQfTiI/PJX+5"
-         "-----END X942 DH PARAMETERS-----";
+   if(name == "ffdhe/ietf/8192")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
-   if(name == "modp/ietf/3072")
-      return
-         "-----BEGIN X942 DH PARAMETERS-----"
-         "MIIDDAKCAYEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqTrS"
-         "yv//////////AgECAoIBgH//////////5IftURC0YRpiYzFFwG4OaJSBJwRFM+Y6"
-         "AQXfUx2JzZEopQQ8xxoCbvfKjNnmnSGNmBWFNvkvihun8Jq2tqjhIvJC2rsxLz9j"
-         "eiYhdNMb9rWF/65begNb9vccNf2tRM/S10+SCL4lj/MklDMo9nItnuEAPlxQsd+C"
-         "zG0kGw4q6c00ix/UfpJnr8GyrpHuUdbLDjF5qxBCqV3PapSDuEtLNrOGGqclXkwC"
-         "eLo2BGUMEL4ZSC8jFxtnHfHPO5YMB0MBzZPB0XYD0Ufa4q74N6YpZO8V5ftKrAuM"
-         "HMqkvnVKtXKK6RMMTH0CiAq5Ry1FVWIW1pmLhoIoPRnUKpDV745dMnZ9woIsbfeF"
-         "RXU4q66DBj7Zy4fC03DyY9X610ZthJnrj0ZKcCUSsM7ncekTDWl3NfiX/QNsxQQy"
-         "bDsBOZ9kNTIpD5WMC72QBl3wi6u9MK62O4TEYF1so3EEcSfQOnLVmKHtrf5wfohH"
-         "JcFokFSdaWV//////////w=="
-         "-----END X942 DH PARAMETERS-----";
+   /* IETF IPsec groups */
 
-   if(name == "modp/srp/3072")
-      return
-         "-----BEGIN DH PARAMETERS-----"
-         "MIIBiAKCAYEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqTrS"
-         "yv//////////AgEF"
-         "-----END DH PARAMETERS-----";
+   if(name == "modp/ietf/1024")
+      {
+      return load_DL_group_info("0xFFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF",
+                                "0x2");
+      }
 
-   if(name == "modp/ietf/4096")
-      return
-         "-----BEGIN X942 DH PARAMETERS-----"
-         "MIIEDAKCAgEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqSEI"
-         "ARpyPBKnh+bXiHGaEL26WyaZwycYavTiPBqUaDS2FQvaJYPpyirUTOjbu8LbBN6O"
-         "+S6O/BQfvsqmKHxZR05rwF2ZspZPoJDDoiM7oYZRW+ftH2EpcM7i16+4G912IXBI"
-         "HNAGkSfVsFqpk7TqmI2P3cGG/7fckKbAj030Nck0BjGZ//////////8CAQICggIA"
-         "f//////////kh+1RELRhGmJjMUXAbg5olIEnBEUz5joBBd9THYnNkSilBDzHGgJu"
-         "98qM2eadIY2YFYU2+S+KG6fwmra2qOEi8kLauzEvP2N6JiF00xv2tYX/rlt6A1v2"
-         "9xw1/a1Ez9LXT5IIviWP8ySUMyj2ci2e4QA+XFCx34LMbSQbDirpzTSLH9R+kmev"
-         "wbKuke5R1ssOMXmrEEKpXc9qlIO4S0s2s4YapyVeTAJ4ujYEZQwQvhlILyMXG2cd"
-         "8c87lgwHQwHNk8HRdgPRR9rirvg3pilk7xXl+0qsC4wcyqS+dUq1corpEwxMfQKI"
-         "CrlHLUVVYhbWmYuGgig9GdQqkNXvjl0ydn3Cgixt94VFdTirroMGPtnLh8LTcPJj"
-         "1frXRm2EmeuPRkpwJRKwzudx6RMNaXc1+Jf9A2zFBDJsOwE5n2Q1MikPlYwLvZAG"
-         "XfCLq70wrrY7hMRgXWyjcQRxJ9A6ctWYoe2t/nB+iEclwWiQVJCEAI05HglTw/Nr"
-         "xDjNCF7dLZNM4ZOMNXpxHg1KNBpbCoXtEsH05RVqJnRt3eFtgm9HfJdHfgoP32VT"
-         "FD4so6c14C7M2Usn0Ehh0RGd0MMorfP2j7CUuGdxa9fcDe67ELgkDmgDSJPq2C1U"
-         "ydp1TEbH7uDDf9vuSFNgR6b6GuSaAxjM//////////8="
-         "-----END X942 DH PARAMETERS-----";
+   if(name == "modp/ietf/1536")
+      {
+      return load_DL_group_info("0xFFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D670C354E4ABC9804F1746C08CA237327FFFFFFFFFFFFFFFF",
+                                "0x2");
+      }
 
-   if(name == "modp/srp/4096")
-      return
-         "-----BEGIN DH PARAMETERS-----"
-         "MIICCAKCAgEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqSEI"
-         "ARpyPBKnh+bXiHGaEL26WyaZwycYavTiPBqUaDS2FQvaJYPpyirUTOjbu8LbBN6O"
-         "+S6O/BQfvsqmKHxZR05rwF2ZspZPoJDDoiM7oYZRW+ftH2EpcM7i16+4G912IXBI"
-         "HNAGkSfVsFqpk7TqmI2P3cGG/7fckKbAj030Nck0BjGZ//////////8CAQU="
-         "-----END DH PARAMETERS-----";
+   if(name == "modp/ietf/2048")
+      {
+      return load_DL_group_info("0x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
+                                "0x2");
+      }
 
-   if(name == "modp/ietf/6144")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIGDAKCAwEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqSEI"
-         "ARpyPBKnh+bXiHGaEL26WyaZwycYavTiPBqUaDS2FQvaJYPpyirUTOjbu8LbBN6O"
-         "+S6O/BQfvsqmKHxZR05rwF2ZspZPoJDDoiM7oYZRW+ftH2EpcM7i16+4G912IXBI"
-         "HNAGkSfVsFqpk7TqmI2P3cGG/7fckKbAj030Nck0AoSSNsP6tNJ8cCbB1NyyYCZG"
-         "3sl1HnY9uje9+P+UBq2eUw7l2zgvQTABrrBqU+2QJ9gxF5cnsIZaiRjaPtvrz5sU"
-         "7UTObLrO1Lsb238UR+bMJUszIFFRK9evQm+49AE3jNK/WYPKAcZLkuzwMuoV0XId"
-         "A/SC185udP721V5wL0aYDIK1qEAxkAscnlnnyX++x+jzI6l6fjbMiL4PHUW3/1ha"
-         "xUvUB7IrQVSqzI9tfr9I4dgUzF7SD4A34KeXFe7ym+MoBqHVi7fF2nb1UKo9ih+/"
-         "8OsZzLGjE9Vc2lbJ7C7yljI4f+jXbjwEaAQ+j2Y/SGDuEr8tWwt0dNbmlPkebcxA"
-         "JP//////////AoIDAH//////////5IftURC0YRpiYzFFwG4OaJSBJwRFM+Y6AQXf"
-         "Ux2JzZEopQQ8xxoCbvfKjNnmnSGNmBWFNvkvihun8Jq2tqjhIvJC2rsxLz9jeiYh"
-         "dNMb9rWF/65begNb9vccNf2tRM/S10+SCL4lj/MklDMo9nItnuEAPlxQsd+CzG0k"
-         "Gw4q6c00ix/UfpJnr8GyrpHuUdbLDjF5qxBCqV3PapSDuEtLNrOGGqclXkwCeLo2"
-         "BGUMEL4ZSC8jFxtnHfHPO5YMB0MBzZPB0XYD0Ufa4q74N6YpZO8V5ftKrAuMHMqk"
-         "vnVKtXKK6RMMTH0CiAq5Ry1FVWIW1pmLhoIoPRnUKpDV745dMnZ9woIsbfeFRXU4"
-         "q66DBj7Zy4fC03DyY9X610ZthJnrj0ZKcCUSsM7ncekTDWl3NfiX/QNsxQQybDsB"
-         "OZ9kNTIpD5WMC72QBl3wi6u9MK62O4TEYF1so3EEcSfQOnLVmKHtrf5wfohHJcFo"
-         "kFSQhACNOR4JU8Pza8Q4zQhe3S2TTOGTjDV6cR4NSjQaWwqF7RLB9OUVaiZ0bd3h"
-         "bYJvR3yXR34KD99lUxQ+LKOnNeAuzNlLJ9BIYdERndDDKK3z9o+wlLhncWvX3A3u"
-         "uxC4JA5oA0iT6tgtVMnadUxGx+7gw3/b7khTYEem+hrkmgFCSRth/VppPjgTYOpu"
-         "WTATI29kuo87Ht0b3vx/ygNWzymHcu2cF6CYANdYNSn2yBPsGIvLk9hDLUSMbR9t"
-         "9efNinaiZzZdZ2pdje2/iiPzZhKlmZAoqJXr16E33HoAm8ZpX6zB5QDjJcl2eBl1"
-         "Cui5DoH6QWvnNzp/e2qvOBejTAZBWtQgGMgFjk8s8+S/32P0eZHUvT8bZkRfB46i"
-         "2/+sLWKl6gPZFaCqVWZHtr9fpHDsCmYvaQfAG/BTy4r3eU3xlANQ6sXb4u07eqhV"
-         "HsUP3/h1jOZY0Ynqrm0rZPYXeUsZHD/0a7ceAjQCH0ezH6Qwdwlflq2Fujprc0p8"
-         "jzbmIBJ//////////wIBAg=="
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/ietf/3072")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
-   if(name == "modp/srp/6144")
-      return
-         "-----BEGIN DH PARAMETERS-----"
-         "MIIDCAKCAwEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqSEI"
-         "ARpyPBKnh+bXiHGaEL26WyaZwycYavTiPBqUaDS2FQvaJYPpyirUTOjbu8LbBN6O"
-         "+S6O/BQfvsqmKHxZR05rwF2ZspZPoJDDoiM7oYZRW+ftH2EpcM7i16+4G912IXBI"
-         "HNAGkSfVsFqpk7TqmI2P3cGG/7fckKbAj030Nck0AoSSNsP6tNJ8cCbB1NyyYCZG"
-         "3sl1HnY9uje9+P+UBq2eUw7l2zgvQTABrrBqU+2QJ9gxF5cnsIZaiRjaPtvrz5sU"
-         "7UTObLrO1Lsb238UR+bMJUszIFFRK9evQm+49AE3jNK/WYPKAcZLkuzwMuoV0XId"
-         "A/SC185udP721V5wL0aYDIK1qEAxkAscnlnnyX++x+jzI6l6fjbMiL4PHUW3/1ha"
-         "xUvUB7IrQVSqzI9tfr9I4dgUzF7SD4A34KeXFe7ym+MoBqHVi7fF2nb1UKo9ih+/"
-         "8OsZzLGjE9Vc2lbJ7C7yljI4f+jXbjwEaAQ+j2Y/SGDuEr8tWwt0dNbmlPkebcxA"
-         "JP//////////AgEF"
-         "-----END DH PARAMETERS-----";
+   if(name == "modp/ietf/4096")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
+
+   if(name == "modp/ietf/6144")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
    if(name == "modp/ietf/8192")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIIDAKCBAEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqSEI"
-         "ARpyPBKnh+bXiHGaEL26WyaZwycYavTiPBqUaDS2FQvaJYPpyirUTOjbu8LbBN6O"
-         "+S6O/BQfvsqmKHxZR05rwF2ZspZPoJDDoiM7oYZRW+ftH2EpcM7i16+4G912IXBI"
-         "HNAGkSfVsFqpk7TqmI2P3cGG/7fckKbAj030Nck0AoSSNsP6tNJ8cCbB1NyyYCZG"
-         "3sl1HnY9uje9+P+UBq2eUw7l2zgvQTABrrBqU+2QJ9gxF5cnsIZaiRjaPtvrz5sU"
-         "7UTObLrO1Lsb238UR+bMJUszIFFRK9evQm+49AE3jNK/WYPKAcZLkuzwMuoV0XId"
-         "A/SC185udP721V5wL0aYDIK1qEAxkAscnlnnyX++x+jzI6l6fjbMiL4PHUW3/1ha"
-         "xUvUB7IrQVSqzI9tfr9I4dgUzF7SD4A34KeXFe7ym+MoBqHVi7fF2nb1UKo9ih+/"
-         "8OsZzLGjE9Vc2lbJ7C7yljI4f+jXbjwEaAQ+j2Y/SGDuEr8tWwt0dNbmlPkebb4R"
-         "WXSjkm8S/uXkOHd8tqky34zYvsTQc7kxujvIMraNndMAdB+nv4r8R+0ldvaTa6Qk"
-         "ZjqrY5xa5PVoNCO0dCvxyXgjjxbL451lLeP9uL78hIrZIiIuBKQDfAcT61eoGiPw"
-         "xzRz/GRs6jBrS8vIhi+Dhd36nUt/osCH6HloMwPtW906Bis89bOieKZtKhP4P0T4"
-         "Ld8xDuB0q2o2RZfomaAlXcFk8xzFCEaFHfmrSBld7X6hsdUQvX7nTXP682vDHs+i"
-         "aDWQRvTrh5+SQAlDi0gcbNeImgAu1e44K8kZDab8Am5HlVjkR1Z36aqeMFDidlaU"
-         "38gfVuiAuW5xYMmA3Zjt09///////////wKCBAB//////////+SH7VEQtGEaYmMx"
-         "RcBuDmiUgScERTPmOgEF31Mdic2RKKUEPMcaAm73yozZ5p0hjZgVhTb5L4obp/Ca"
-         "trao4SLyQtq7MS8/Y3omIXTTG/a1hf+uW3oDW/b3HDX9rUTP0tdPkgi+JY/zJJQz"
-         "KPZyLZ7hAD5cULHfgsxtJBsOKunNNIsf1H6SZ6/Bsq6R7lHWyw4xeasQQqldz2qU"
-         "g7hLSzazhhqnJV5MAni6NgRlDBC+GUgvIxcbZx3xzzuWDAdDAc2TwdF2A9FH2uKu"
-         "+DemKWTvFeX7SqwLjBzKpL51SrVyiukTDEx9AogKuUctRVViFtaZi4aCKD0Z1CqQ"
-         "1e+OXTJ2fcKCLG33hUV1OKuugwY+2cuHwtNw8mPV+tdGbYSZ649GSnAlErDO53Hp"
-         "Ew1pdzX4l/0DbMUEMmw7ATmfZDUyKQ+VjAu9kAZd8IurvTCutjuExGBdbKNxBHEn"
-         "0Dpy1Zih7a3+cH6IRyXBaJBUkIQAjTkeCVPD82vEOM0IXt0tk0zhk4w1enEeDUo0"
-         "GlsKhe0SwfTlFWomdG3d4W2Cb0d8l0d+Cg/fZVMUPiyjpzXgLszZSyfQSGHREZ3Q"
-         "wyit8/aPsJS4Z3Fr19wN7rsQuCQOaANIk+rYLVTJ2nVMRsfu4MN/2+5IU2BHpvoa"
-         "5JoBQkkbYf1aaT44E2DqblkwEyNvZLqPOx7dG978f8oDVs8ph3LtnBegmADXWDUp"
-         "9sgT7BiLy5PYQy1EjG0fbfXnzYp2omc2XWdqXY3tv4oj82YSpZmQKKiV69ehN9x6"
-         "AJvGaV+sweUA4yXJdngZdQrouQ6B+kFr5zc6f3tqrzgXo0wGQVrUIBjIBY5PLPPk"
-         "v99j9HmR1L0/G2ZEXweOotv/rC1ipeoD2RWgqlVmR7a/X6Rw7ApmL2kHwBvwU8uK"
-         "93lN8ZQDUOrF2+LtO3qoVR7FD9/4dYzmWNGJ6q5tK2T2F3lLGRw/9Gu3HgI0Ah9H"
-         "sx+kMHcJX5athbo6a3NKfI823wisulHJN4l/cvIcO75bVJlvxmxfYmg53JjdHeQZ"
-         "W0bO6YA6D9PfxX4j9pK7e0m10hIzHVWxzi1yerQaEdo6FfjkvBHHi2XxzrKW8f7c"
-         "X35CRWyRERcCUgG+A4n1q9QNEfhjmjn+MjZ1GDWl5eRDF8HC7v1Opb/RYEP0PLQZ"
-         "gfat7p0DFZ562dE8UzaVCfwfonwW75iHcDpVtRsiy/RM0BKu4LJ5jmKEI0KO/NWk"
-         "DK72v1DY6ohev3Omuf15teGPZ9E0GsgjenXDz8kgBKHFpA42a8RNABdq9xwV5IyG"
-         "034BNyPKrHIjqzv01U8YKHE7K0pv5A+rdEBctziwZMBuzHbp7///////////AgEC"
-         "-----END DSA PARAMETERS-----";
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
-   if(name == "modp/srp/8192")
-      return
-         "-----BEGIN DH PARAMETERS-----"
-         "MIIECAKCBAEA///////////JD9qiIWjCNMTGYouA3BzRKQJOCIpnzHQCC76mOxOb"
-         "IlFKCHmONATd75UZs806QxswKwpt8l8UN0/hNW1tUcJF5IW1dmJefsb0TELppjft"
-         "awv/XLb0Brft7jhr+1qJn6WunyQRfEsf5kkoZlHs5Fs9wgB8uKFjvwWY2kg2HFXT"
-         "mmkWP6j9JM9fg2VdI9yjrZYcYvNWIIVSu57VKQdwlpZtZww1Tkq8mATxdGwIyhgh"
-         "fDKQXkYuNs474553LBgOhgObJ4Oi7Aeij7XFXfBvTFLJ3ivL9pVYFxg5lUl86pVq"
-         "5RXSJhiY+gUQFXKOWoqqxC2tMxcNBFB6M6hVIavfHLpk7PuFBFjb7wqK6nFXXQYM"
-         "fbOXD4Wm4eTHq/WujNsJM9cejJTgSiVhnc7j0iYa0u5r8S/6BtmKCGTYdgJzPshq"
-         "ZFIfKxgXeyAMu+EXV3phXWx3CYjAutlG4gjiT6B05asxQ9tb/OD9EI5LgtEgqSEI"
-         "ARpyPBKnh+bXiHGaEL26WyaZwycYavTiPBqUaDS2FQvaJYPpyirUTOjbu8LbBN6O"
-         "+S6O/BQfvsqmKHxZR05rwF2ZspZPoJDDoiM7oYZRW+ftH2EpcM7i16+4G912IXBI"
-         "HNAGkSfVsFqpk7TqmI2P3cGG/7fckKbAj030Nck0AoSSNsP6tNJ8cCbB1NyyYCZG"
-         "3sl1HnY9uje9+P+UBq2eUw7l2zgvQTABrrBqU+2QJ9gxF5cnsIZaiRjaPtvrz5sU"
-         "7UTObLrO1Lsb238UR+bMJUszIFFRK9evQm+49AE3jNK/WYPKAcZLkuzwMuoV0XId"
-         "A/SC185udP721V5wL0aYDIK1qEAxkAscnlnnyX++x+jzI6l6fjbMiL4PHUW3/1ha"
-         "xUvUB7IrQVSqzI9tfr9I4dgUzF7SD4A34KeXFe7ym+MoBqHVi7fF2nb1UKo9ih+/"
-         "8OsZzLGjE9Vc2lbJ7C7yljI4f+jXbjwEaAQ+j2Y/SGDuEr8tWwt0dNbmlPkebb4R"
-         "WXSjkm8S/uXkOHd8tqky34zYvsTQc7kxujvIMraNndMAdB+nv4r8R+0ldvaTa6Qk"
-         "ZjqrY5xa5PVoNCO0dCvxyXgjjxbL451lLeP9uL78hIrZIiIuBKQDfAcT61eoGiPw"
-         "xzRz/GRs6jBrS8vIhi+Dhd36nUt/osCH6HloMwPtW906Bis89bOieKZtKhP4P0T4"
-         "Ld8xDuB0q2o2RZfomaAlXcFk8xzFCEaFHfmrSBld7X6hsdUQvX7nTXP682vDHs+i"
-         "aDWQRvTrh5+SQAlDi0gcbNeImgAu1e44K8kZDab8Am5HlVjkR1Z36aqeMFDidlaU"
-         "38gfVuiAuW5xYMmA3Zjt09///////////wIBEw=="
-         "-----END DH PARAMETERS-----";
+   /* SRP groups */
 
-   if(name == "dsa/jce/1024")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIBHgKBgQD9f1OBHXUSKVLfSpwu7OTn9hG3UjzvRADDHj+AtlEmaUVdQCJR+1k9"
-         "jVj6v8X1ujD2y5tVbNeBO4AdNG/yZmC3a5lQpaSfn+gEexAiwk+7qdf+t8Yb+DtX"
-         "58aophUPBPuD9tPFHsMCNVQTWhaRMvZ1864rYdcq7/IiAxmd0UgBxwIVAJdgUI8V"
-         "IwvMspK5gqLrhAvwWBz1AoGARpYDUS4wJ4zTlHWV2yLuyYJqYyKtyXNE9B10DDJX"
-         "JMj577qn1NgD/4xgnc0QDrxb38+tfGpCX66nhuogUOvpg1HqH9of3yTWlHqmuaoj"
-         "dmlTgC9NfUqOy6BtGXaKJJH/sW0O+cQ6mbX3FnL/bwoktETQc20E04oaEyLa9s3Y"
-         "jJ0="
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/srp/1024")
+      {
+      return load_DL_group_info("0xEEAF0AB9ADB38DD69C33F80AFA8FC5E86072618775FF3C0B9EA2314C9C256576D674DF7496EA81D3383B4813D692C6E0E0D5D8E250B98BE48E495C1D6089DAD15DC7D7B46154D6B6CE8EF4AD69B15D4982559B297BCF1885C529F566660E57EC68EDBC3C05726CC02FD4CBF4976EAA9AFD5138FE8376435B9FC61D2FC0EB06E3",
+                                "0x2");
+      }
 
-   if(name == "dsa/botan/2048")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIICLAKCAQEAkcSKT9+898Aq6V59oSYSK13Shk9Vm4fo50oobVL1m9HeaN/WRdDg"
-         "DGDAgAMYkZgDdO61lKUyv9Z7mgnqxLhmOgeRDmjzlGX7cEDSXfE5MuusQ0elMOy6"
-         "YchU+biA08DDZgCAWHxFVm2t4mvVo5S+CTtMDyS1r/747GxbPlf7iQJam8FnaZMh"
-         "MeFtPJTvyrGNDfBhIDzFPmEDvHLVWUv9QMplOA9EqahR3LB1SV/AM6ilgHGhvXj+"
-         "BS9mVVZI60txnSr+i0iA+NrW8VgYuhePiSdMhwvpuW6wjEbEAEDMLv4d+xsYaN0x"
-         "nePDSjKmOrbrEiQgmkGWgMx5AtFyjU354QIhAIzX1FD4bwrZTu5M5GmodW0evRBY"
-         "JBlD6v+ws1RYXpJNAoIBAA2fXgdhtNvRgz1qsalhoJlsXyIwP3LYTBQPZ8Qx2Uq1"
-         "cVvqgaDJjTnOS8941rnryJXTT+idlAkdWEhhXvFfXobxHZb2yWniA936WDVkIKSc"
-         "tES1lbkBqTPP4HZ7WU8YoHt/kd7NukRriJkPePL/kfL+fNQ/0uRtGOraH3u2YCxh"
-         "f27zpLKE8v2boQo2BC3o+oeiyjZZf+yBFXoUheRAQd8CgwERy4gLvm7UlIFIhvll"
-         "zcMTX1zPE4Nyi/ZbgG+WksCxDWxMCcdabKO0ATyxarLBBfa+I66pAA6rIXiYX5cs"
-         "mAV+HIbkTnIYaI6krg82NtzKdFydzU5q/7Z8y8E9YTE="
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/srp/1536")
+      {
+      /*
+      (p-1)/2 is prime, but g is not a generator of subgroup q so set q == 0 to bypass generator check
 
-   if(name == "dsa/botan/3072")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIDLAKCAYEA5LUIgHWWY1heFCRgyi2d/xMviuTIQN2jomZoiRJP5WOLhOiim3rz"
-         "+hIJvmv8S1By7Tsrc4e68/hX9HioAijvNgC3az3Pth0g00RlslBtLK+H3259wM6R"
-         "vS0Wekb2rcwxxTHk+cervbkq3fNbCoBsZikqX14X6WTdCZkDczrEKKs12A6m9oW/"
-         "uovkBo5UGK5eytno/wc94rY+Tn6tNciptwtb1Hz7iNNztm83kxk5sKtxvVWVgJCG"
-         "2gFVM30YWg5Ps2pRmxtiArhZHmACRJzxzTpmOE9tIHOxzXO+ypO68eGmEX0COPIi"
-         "rh7X/tGFqJDn9n+rj+uXU8wTSlGD3+h64llfe1wtn7tCJJ/dWVE+HTOWs+sv2GaE"
-         "8oWoRI/nV6ApiBxAdguU75Gb35dAw4OJWZ7FGm6btRmo4GhJHpzgovz+PLYNZs8N"
-         "+tIKjsaEBIaEphREV1vRck1zUrRKdgB3s71r04XOWwpyUMwL92jagpI4Buuc+7E4"
-         "hDcxthggjHWbAiEAs+vTZOxp74zzuvZDt1c0sWM5suSeXN4bWcHp+0DuDFsCggGA"
-         "K+0h7vg5ZKIwrom7px2ffDnFL8gim047x+WUTTKdoQ8BDqyee69sAJ/E6ylgcj4r"
-         "Vt9GY+TDrIAOkljeL3ZJ0gZ4KJP4Ze/KSY0u7zAHTqXop6smJxKk2UovOwuaku5A"
-         "D7OKPMWaXcfkNtXABLIuNQKDgbUck0B+sy1K4P1Cy0XhLQ7O6KJiOO3iCCp7FSIR"
-         "PGbO+NdFxs88uUX4TS9N4W1Epx3hmCcOE/A1U8iLjTI60LlIob8hA6lJl5tu0W+1"
-         "88lT2Vt8jojKZ9z1pjb7nKOdkkIV96iE7Wx+48ltjZcVQnl0t8Q1EoLhPTdz99KL"
-         "RS8QiSoTx1hzKN6kgntrNpsqjcFyrcWD9R8qZZjFSD5bxGewL5HQWcQC0Y4sJoD3"
-         "dqoG9JKAoscsF8xC1bbnQMXEsas8UcLtCSviotiwU65Xc9FCXtKwjwbi3VBZLfGk"
-         "eMFVkc39EVZP+I/zi3IdQjkv2kcyEtz9jS2IqXagCv/m//tDCjWeZMorNRyiQSOU"
-         "-----END DSA PARAMETERS-----";
+      This doesn't matter for SRP
+      */
+      return load_DL_group_info("0x9DEF3CAFB939277AB1F12A8617A47BBBDBA51DF499AC4C80BEEEA9614B19CC4D5F4F5F556E27CBDE51C6A94BE4607A291558903BA0D0F84380B655BB9A22E8DCDF028A7CEC67F0D08134B1C8B97989149B609E0BE3BAB63D47548381DBC5B1FC764E3F4B53DD9DA1158BFD3E2B9C8CF56EDF019539349627DB2FD53D24B7C48665772E437D6C7F8CE442734AF7CCB7AE837C264AE3A9BEB87F8A2FE9B8B5292E5A021FFF5E91479E8CE7A28C2442C6F315180F93499A234DCF76E3FED135F9BB",
+                                "0",
+                                "0x2");
+      }
 
-   if(name == "ffdhe/ietf/2048")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIICDAKCAQEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz"
-         "+8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a"
-         "87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7"
-         "YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi"
-         "7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD"
-         "ssbzSibBsu/6iGtCOGEoXJf//////////wKCAQB//////////9b8KixRXaVNV+4r"
-         "EBOennjsXOLB5xabStTwmyCKMhn95knO5xJNn3y+l/GxsYY67HtA2QFXYjC9ae+P"
-         "aur+srCSGfqPr4M3aEKxsqqe9o152quJrz+r5JrMJ4Y4cHNFu/FTRO159/Q5Dvis"
-         "UJtW85qYVmUnpB08vV4FWMFZkn2w6IRUpdlkcf3ctW1bsGv6NA6noVHvHKb6Vyt2"
-         "87G5XYyFg9PkdwU2uE8BfnDm+/F2YBoCZpQaF7DIuX9OdMLB/8cniRl3eUDB4f8d"
-         "jaY31rmd2v5eF2EQAuLHeMG+i0HZY3mlE2DZd/1ENaEcMJQuS///////////AgEC"
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/srp/2048")
+      {
+      return load_DL_group_info("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
+                                "0x2");
+      }
 
-   if(name == "ffdhe/ietf/3072")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIDDAKCAYEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz"
-         "+8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a"
-         "87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7"
-         "YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi"
-         "7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD"
-         "ssbzSibBsu/6iGtCOGEfz9zeNVs7ZRkDW7w09N75nAI4YbRvydbmyQd62R0mkff3"
-         "7lmMsPrBhtkcrv4TCYUTknC0EwyTvEN5RPT9RFLi103TZPLiHnH1S/9croKrnJ32"
-         "nuhtK8UiNjoNq8Uhl5sN6todv5pC1cRITgq80Gv6U93vPBsg7j/VnXwl5B0rZsYu"
-         "N///////////AoIBgH//////////1vwqLFFdpU1X7isQE56eeOxc4sHnFptK1PCb"
-         "IIoyGf3mSc7nEk2ffL6X8bGxhjrse0DZAVdiML1p749q6v6ysJIZ+o+vgzdoQrGy"
-         "qp72jXnaq4mvP6vkmswnhjhwc0W78VNE7Xn39DkO+KxQm1bzmphWZSekHTy9XgVY"
-         "wVmSfbDohFSl2WRx/dy1bVuwa/o0DqehUe8cpvpXK3bzsbldjIWD0+R3BTa4TwF+"
-         "cOb78XZgGgJmlBoXsMi5f050wsH/xyeJGXd5QMHh/x2NpjfWuZ3a/l4XYRAC4sd4"
-         "wb6LQdljeaUTYNl3/UQ1oRwwj+fubxqtnbKMga3eGnpvfM4BHDDaN+Trc2SDvWyO"
-         "k0j7+/csxlh9YMNsjld/CYTCick4WgmGSd4hvKJ6fqIpcWum6bJ5cQ84+qX/rldB"
-         "Vc5O+090NpXikRsdBtXikMvNhvVtDt/NIWriJCcFXmg1/Snu954NkHcf6s6+EvIO"
-         "lbNjFxv//////////wIBAg=="
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/srp/3072")
+      {
+      return load_DL_group_info("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
+                                "0x5");
+      }
 
-   if(name == "ffdhe/ietf/4096")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIEDAKCAgEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz"
-         "+8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a"
-         "87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7"
-         "YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi"
-         "7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD"
-         "ssbzSibBsu/6iGtCOGEfz9zeNVs7ZRkDW7w09N75nAI4YbRvydbmyQd62R0mkff3"
-         "7lmMsPrBhtkcrv4TCYUTknC0EwyTvEN5RPT9RFLi103TZPLiHnH1S/9croKrnJ32"
-         "nuhtK8UiNjoNq8Uhl5sN6todv5pC1cRITgq80Gv6U93vPBsg7j/VnXwl5B0rZp4e"
-         "8W5vUsMWTfT7eTDp5OWIV7asfV9C1p9tGHdjzx1VA0AEh/VbpX4xzHpxNciG77Qx"
-         "iu1qHgEtnmgyqQdgCpGBMMRtx3j5ca0AOAkpmaMzy4t6Gh25PXFAADwqTs6p+Y0K"
-         "zAqCkc3OyX3Pjsm1Wn+IpGtNtahR9EGC4caKAH5eZV9q//////////8CggIAf///"
-         "///////W/CosUV2lTVfuKxATnp547FziwecWm0rU8JsgijIZ/eZJzucSTZ98vpfx"
-         "sbGGOux7QNkBV2IwvWnvj2rq/rKwkhn6j6+DN2hCsbKqnvaNedqria8/q+SazCeG"
-         "OHBzRbvxU0Tteff0OQ74rFCbVvOamFZlJ6QdPL1eBVjBWZJ9sOiEVKXZZHH93LVt"
-         "W7Br+jQOp6FR7xym+lcrdvOxuV2MhYPT5HcFNrhPAX5w5vvxdmAaAmaUGhewyLl/"
-         "TnTCwf/HJ4kZd3lAweH/HY2mN9a5ndr+XhdhEALix3jBvotB2WN5pRNg2Xf9RDWh"
-         "HDCP5+5vGq2dsoyBrd4aem98zgEcMNo35OtzZIO9bI6TSPv79yzGWH1gw2yOV38J"
-         "hMKJyThaCYZJ3iG8onp+oilxa6bpsnlxDzj6pf+uV0FVzk77T3Q2leKRGx0G1eKQ"
-         "y82G9W0O380hauIkJwVeaDX9Ke73ng2Qdx/qzr4S8g6Vs08PeLc3qWGLJvp9vJh0"
-         "8nLEK9tWPq+ha0+2jDux546qgaACQ/qt0r8Y5j04muRDd9oYxXa1DwCWzzQZVIOw"
-         "BUjAmGI247x8uNaAHASUzNGZ5cW9DQ7cnrigAB4VJ2dU/MaFZgVBSObnZL7nx2Ta"
-         "rT/EUjWm2tQo+iDBcONFAD8vMq+1f/////////8CAQI="
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/srp/4096")
+      {
+      return load_DL_group_info("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
+                                "0x5");
+      }
 
-   if(name == "ffdhe/ietf/6144")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIGDAKCAwEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz"
-         "+8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a"
-         "87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7"
-         "YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi"
-         "7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD"
-         "ssbzSibBsu/6iGtCOGEfz9zeNVs7ZRkDW7w09N75nAI4YbRvydbmyQd62R0mkff3"
-         "7lmMsPrBhtkcrv4TCYUTknC0EwyTvEN5RPT9RFLi103TZPLiHnH1S/9croKrnJ32"
-         "nuhtK8UiNjoNq8Uhl5sN6todv5pC1cRITgq80Gv6U93vPBsg7j/VnXwl5B0rZp4e"
-         "8W5vUsMWTfT7eTDp5OWIV7asfV9C1p9tGHdjzx1VA0AEh/VbpX4xzHpxNciG77Qx"
-         "iu1qHgEtnmgyqQdgCpGBMMRtx3j5ca0AOAkpmaMzy4t6Gh25PXFAADwqTs6p+Y0K"
-         "zAqCkc3OyX3Pjsm1Wn+IpGtNtahR9EGC4caKAH5eDdkCC/1ktkUDbHpOZ30sOFMq"
-         "OiO6RELK9T6mO7RUMpt2JMiRe91kscD9TLOOjDNMcBw6za0GV/zP7HGbH1w+TkYE"
-         "HziBR/tM/bR3pSRx96mpaRC4VTIu22NA2KAO8JI1BRHjCr7B//njom5/sp+MGDAj"
-         "w1h+ONoAd9m0dj5OS5Syu8GUxmUed8r5ku6qwCMqKBv2s6c5wSJhFoIK6NtYR6Z8"
-         "vvnJCRtGLVOM1ysDdGrnf15iKSwxFWKoRlBdyC24VDOK5J9SNclbkReMzy3Vys70"
-         "A+ydGBDGJysEWztx+dxrgNY/3UqOmtseaWKmlSbUMWHBpB1XDXk42tSkDjKc0OQO"
-         "Zf//////////AoIDAH//////////1vwqLFFdpU1X7isQE56eeOxc4sHnFptK1PCb"
-         "IIoyGf3mSc7nEk2ffL6X8bGxhjrse0DZAVdiML1p749q6v6ysJIZ+o+vgzdoQrGy"
-         "qp72jXnaq4mvP6vkmswnhjhwc0W78VNE7Xn39DkO+KxQm1bzmphWZSekHTy9XgVY"
-         "wVmSfbDohFSl2WRx/dy1bVuwa/o0DqehUe8cpvpXK3bzsbldjIWD0+R3BTa4TwF+"
-         "cOb78XZgGgJmlBoXsMi5f050wsH/xyeJGXd5QMHh/x2NpjfWuZ3a/l4XYRAC4sd4"
-         "wb6LQdljeaUTYNl3/UQ1oRwwj+fubxqtnbKMga3eGnpvfM4BHDDaN+Trc2SDvWyO"
-         "k0j7+/csxlh9YMNsjld/CYTCick4WgmGSd4hvKJ6fqIpcWum6bJ5cQ84+qX/rldB"
-         "Vc5O+090NpXikRsdBtXikMvNhvVtDt/NIWriJCcFXmg1/Snu954NkHcf6s6+EvIO"
-         "lbNPD3i3N6lhiyb6fbyYdPJyxCvbVj6voWtPtow7seeOqoGgAkP6rdK/GOY9OJrk"
-         "Q3faGMV2tQ8Als80GVSDsAVIwJhiNuO8fLjWgBwElMzRmeXFvQ0O3J64oAAeFSdn"
-         "VPzGhWYFQUjm52S+58dk2q0/xFI1ptrUKPogwXDjRQA/LwbsgQX+slsigbY9JzO+"
-         "lhwplR0R3SIhZXqfUx3aKhlNuxJkSL3usljgfqZZx0YZpjgOHWbWgyv+Z/Y4zY+u"
-         "HycjAg+cQKP9pn7aO9KSOPvU1LSIXCqZF22xoGxQB3hJGoKI8YVfYP/88dE3P9lP"
-         "xgwYEeGsPxxtADvs2jsfJyXKWV3gymMyjzvlfMl3VWARlRQN+1nTnOCRMItBBXRt"
-         "rCPTPl985ISNoxapxmuVgbo1c7+vMRSWGIqxVCMoLuQW3CoZxXJPqRrkrciLxmeW"
-         "6uVnegH2TowIYxOVgi2duPzuNcBrH+6lR01tjzSxU0qTahiw4NIOq4a8nG1qUgcZ"
-         "TmhyBzL//////////wIBAg=="
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/srp/6144")
+      {
+      return load_DL_group_info("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
+                                "0x5");
+      }
 
-   if(name == "ffdhe/ietf/8192")
-      return
-         "-----BEGIN DSA PARAMETERS-----"
-         "MIIIDAKCBAEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz"
-         "+8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a"
-         "87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7"
-         "YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi"
-         "7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD"
-         "ssbzSibBsu/6iGtCOGEfz9zeNVs7ZRkDW7w09N75nAI4YbRvydbmyQd62R0mkff3"
-         "7lmMsPrBhtkcrv4TCYUTknC0EwyTvEN5RPT9RFLi103TZPLiHnH1S/9croKrnJ32"
-         "nuhtK8UiNjoNq8Uhl5sN6todv5pC1cRITgq80Gv6U93vPBsg7j/VnXwl5B0rZp4e"
-         "8W5vUsMWTfT7eTDp5OWIV7asfV9C1p9tGHdjzx1VA0AEh/VbpX4xzHpxNciG77Qx"
-         "iu1qHgEtnmgyqQdgCpGBMMRtx3j5ca0AOAkpmaMzy4t6Gh25PXFAADwqTs6p+Y0K"
-         "zAqCkc3OyX3Pjsm1Wn+IpGtNtahR9EGC4caKAH5eDdkCC/1ktkUDbHpOZ30sOFMq"
-         "OiO6RELK9T6mO7RUMpt2JMiRe91kscD9TLOOjDNMcBw6za0GV/zP7HGbH1w+TkYE"
-         "HziBR/tM/bR3pSRx96mpaRC4VTIu22NA2KAO8JI1BRHjCr7B//njom5/sp+MGDAj"
-         "w1h+ONoAd9m0dj5OS5Syu8GUxmUed8r5ku6qwCMqKBv2s6c5wSJhFoIK6NtYR6Z8"
-         "vvnJCRtGLVOM1ysDdGrnf15iKSwxFWKoRlBdyC24VDOK5J9SNclbkReMzy3Vys70"
-         "A+ydGBDGJysEWztx+dxrgNY/3UqOmtseaWKmlSbUMWHBpB1XDXk42tSkDjKcz/Rq"
-         "qjatAEz2AMg4HkJaMdlRrmT9sj/OyVCdQ2h/62nt0cxeC4zDvfZLEO+GtjFCo6uI"
-         "KVVbL3R8kyZlyywPHMAb1wIpOIg50q8F5FRQSseLdYKCKEbAujXDX1xZFgzARv2C"
-         "UVQfxoychrAiu3CZh2pGDnRRqKkxCXA/7hwhfmw4JuUsUappHg5CPPyZ6eMWUMEh"
-         "e2JIFs2tmpX51bgBlIjZwKCh/jB1pXfiMYP4HUo/L6RXHvyM4LqKT+i2hV3+crCm"
-         "bt7S+6v75Yow+vq+HF1xqH4vdB74wf6G/qa7/eUwZ38Nl9EdSfeoRD0IIuUGqfRh"
-         "TgEeKpSDj/iM1oyLt8XGQkz//////////wKCBAB//////////9b8KixRXaVNV+4r"
-         "EBOennjsXOLB5xabStTwmyCKMhn95knO5xJNn3y+l/GxsYY67HtA2QFXYjC9ae+P"
-         "aur+srCSGfqPr4M3aEKxsqqe9o152quJrz+r5JrMJ4Y4cHNFu/FTRO159/Q5Dvis"
-         "UJtW85qYVmUnpB08vV4FWMFZkn2w6IRUpdlkcf3ctW1bsGv6NA6noVHvHKb6Vyt2"
-         "87G5XYyFg9PkdwU2uE8BfnDm+/F2YBoCZpQaF7DIuX9OdMLB/8cniRl3eUDB4f8d"
-         "jaY31rmd2v5eF2EQAuLHeMG+i0HZY3mlE2DZd/1ENaEcMI/n7m8arZ2yjIGt3hp6"
-         "b3zOARww2jfk63Nkg71sjpNI+/v3LMZYfWDDbI5XfwmEwonJOFoJhkneIbyien6i"
-         "KXFrpumyeXEPOPql/65XQVXOTvtPdDaV4pEbHQbV4pDLzYb1bQ7fzSFq4iQnBV5o"
-         "Nf0p7veeDZB3H+rOvhLyDpWzTw94tzepYYsm+n28mHTycsQr21Y+r6FrT7aMO7Hn"
-         "jqqBoAJD+q3SvxjmPTia5EN32hjFdrUPAJbPNBlUg7AFSMCYYjbjvHy41oAcBJTM"
-         "0Znlxb0NDtyeuKAAHhUnZ1T8xoVmBUFI5udkvufHZNqtP8RSNaba1Cj6IMFw40UA"
-         "Py8G7IEF/rJbIoG2PSczvpYcKZUdEd0iIWV6n1Md2ioZTbsSZEi97rJY4H6mWcdG"
-         "GaY4Dh1m1oMr/mf2OM2Prh8nIwIPnECj/aZ+2jvSkjj71NS0iFwqmRdtsaBsUAd4"
-         "SRqCiPGFX2D//PHRNz/ZT8YMGBHhrD8cbQA77No7Hyclylld4MpjMo875XzJd1Vg"
-         "EZUUDftZ05zgkTCLQQV0bawj0z5ffOSEjaMWqcZrlYG6NXO/rzEUlhiKsVQjKC7k"
-         "FtwqGcVyT6ka5K3Ii8ZnlurlZ3oB9k6MCGMTlYItnbj87jXAax/upUdNbY80sVNK"
-         "k2oYsODSDquGvJxtalIHGU5n+jVVG1aAJnsAZBwPIS0Y7KjXMn7ZH+dkqE6htD/1"
-         "tPbo5i8FxmHe+yWId8NbGKFR1cQUqq2Xuj5JkzLllgeOYA3rgRScRBzpV4LyKigl"
-         "Y8W6wUEUI2BdGuGvriyLBmAjfsEoqg/jRk5DWBFduEzDtSMHOijUVJiEuB/3DhC/"
-         "NhwTcpYo1TSPByEefkz08YsoYJC9sSQLZtbNSvzq3ADKRGzgUFD/GDrSu/EYwfwO"
-         "pR+X0iuPfkZwXUUn9FtCrv85WFM3b2l91f3yxRh9fV8OLrjUPxe6D3xg/0N/U13+"
-         "8pgzv4bL6I6k+9QiHoQRcoNU+jCnAI8VSkHH/EZrRkXb4uMhJn//////////AgEC"
-         "-----END DSA PARAMETERS-----";
+   if(name == "modp/srp/8192")
+      {
+      return load_DL_group_info("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
+                                "0x13");
+      }
+
+   /* DSA groups */
+
+   if(name == "dsa/jce/1024")
+      {
+      return load_DL_group_info("0xFD7F53811D75122952DF4A9C2EECE4E7F611B7523CEF4400C31E3F80B6512669455D402251FB593D8D58FABFC5F5BA30F6CB9B556CD7813B801D346FF26660B76B9950A5A49F9FE8047B1022C24FBBA9D7FEB7C61BF83B57E7C6A8A6150F04FB83F6D3C51EC3023554135A169132F675F3AE2B61D72AEFF22203199DD14801C7",
+                                "0x9760508F15230BCCB292B982A2EB840BF0581CF5",
+                                "0x469603512E30278CD3947595DB22EEC9826A6322ADC97344F41D740C325724C8F9EFBAA7D4D803FF8C609DCD100EBC5BDFCFAD7C6A425FAEA786EA2050EBE98351EA1FDA1FDF24D6947AA6B9AA23766953802F4D7D4A8ECBA06D19768A2491FFB16D0EF9C43A99B5F71672FF6F0A24B444D0736D04D38A1A1322DAF6CDD88C9D");
+      }
+
+   if(name == "dsa/botan/2048")
+      {
+      return load_DL_group_info("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
+                                "0x8CD7D450F86F0AD94EEE4CE469A8756D1EBD1058241943EAFFB0B354585E924D",
+                                "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
+      }
+
+   if(name == "dsa/botan/3072")
+      {
+      return load_DL_group_info("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
+                                "0xB3EBD364EC69EF8CF3BAF643B75734B16339B2E49E5CDE1B59C1E9FB40EE0C5B",
+                                "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
+      }
 
-   return "";
+   return std::shared_ptr<DL_Group_Data>();
    }
 
 }
diff --git a/src/lib/pubkey/dsa/dsa.cpp b/src/lib/pubkey/dsa/dsa.cpp
index 9a8418d46..f1d412013 100644
--- a/src/lib/pubkey/dsa/dsa.cpp
+++ b/src/lib/pubkey/dsa/dsa.cpp
@@ -47,14 +47,14 @@ DSA_PrivateKey::DSA_PrivateKey(RandomNumberGenerator& rng,
    else
       m_x = x_arg;
 
-   m_y = power_mod(group_g(), m_x, group_p());
+   m_y = m_group.power_g_p(m_x);
    }
 
 DSA_PrivateKey::DSA_PrivateKey(const AlgorithmIdentifier& alg_id,
                                const secure_vector<uint8_t>& key_bits) :
    DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_57)
    {
-   m_y = power_mod(group_g(), m_x, group_p());
+   m_y = m_group.power_g_p(m_x);
    }
 
 /*
@@ -81,9 +81,8 @@ class DSA_Signature_Operation final : public PK_Ops::Signature_with_EMSA
    public:
       DSA_Signature_Operation(const DSA_PrivateKey& dsa, const std::string& emsa) :
          PK_Ops::Signature_with_EMSA(emsa),
-         m_q(dsa.group_q()),
+         m_group(dsa.get_group()),
          m_x(dsa.get_x()),
-         m_powermod_g_p(dsa.group_g(), dsa.group_p()),
          m_mod_q(dsa.group_q())
          {
 #if defined(BOTAN_HAS_RFC6979_GENERATOR)
@@ -91,14 +90,13 @@ class DSA_Signature_Operation final : public PK_Ops::Signature_with_EMSA
 #endif
          }
 
-      size_t max_input_bits() const override { return m_q.bits(); }
+      size_t max_input_bits() const override { return m_group.get_q().bits(); }
 
       secure_vector<uint8_t> raw_sign(const uint8_t msg[], size_t msg_len,
                                    RandomNumberGenerator& rng) override;
    private:
-      const BigInt& m_q;
+      const DL_Group m_group;
       const BigInt& m_x;
-      Fixed_Base_Power_Mod m_powermod_g_p;
       Modular_Reducer m_mod_q;
 #if defined(BOTAN_HAS_RFC6979_GENERATOR)
       std::string m_rfc6979_hash;
@@ -109,36 +107,38 @@ secure_vector<uint8_t>
 DSA_Signature_Operation::raw_sign(const uint8_t msg[], size_t msg_len,
                                   RandomNumberGenerator& rng)
    {
+   const BigInt& q = m_group.get_q();
+
    BigInt i(msg, msg_len);
 
-   while(i >= m_q)
-      i -= m_q;
+   while(i >= q)
+      i -= q;
 
 #if defined(BOTAN_HAS_RFC6979_GENERATOR)
    BOTAN_UNUSED(rng);
-   const BigInt k = generate_rfc6979_nonce(m_x, m_q, i, m_rfc6979_hash);
+   const BigInt k = generate_rfc6979_nonce(m_x, q, i, m_rfc6979_hash);
 #else
-   const BigInt k = BigInt::random_integer(rng, 1, m_q);
+   const BigInt k = BigInt::random_integer(rng, 1, q);
 #endif
 
 #if defined(BOTAN_TARGET_OS_HAS_THREADS)
    auto future_r = std::async(std::launch::async,
-                              [&]() { return m_mod_q.reduce(m_powermod_g_p(k)); });
+                              [&]() { return m_mod_q.reduce(m_group.power_g_p(k)); });
 
-   BigInt s = inverse_mod(k, m_q);
+   BigInt s = inverse_mod(k, q);
    const BigInt r = future_r.get();
 #else
-   BigInt s = inverse_mod(k, m_q);
-   const BigInt r = m_mod_q.reduce(m_powermod_g_p(k));
+   BigInt s = inverse_mod(k, q);
+   const BigInt r = m_mod_q.reduce(m_group.power_g_p(k));
 #endif
 
    s = m_mod_q.multiply(s, mul_add(m_x, r, i));
 
    // With overwhelming probability, a bug rather than actual zero r/s
-   BOTAN_ASSERT(s != 0, "invalid s");
-   BOTAN_ASSERT(r != 0, "invalid r");
+   if(r.is_zero() || s.is_zero())
+      throw Internal_Error("Computed zero r/s during DSA signature");
 
-   return BigInt::encode_fixed_length_int_pair(r, s, m_q.bytes());
+   return BigInt::encode_fixed_length_int_pair(r, s, q.bytes());
    }
 
 /**
@@ -150,52 +150,56 @@ class DSA_Verification_Operation final : public PK_Ops::Verification_with_EMSA
       DSA_Verification_Operation(const DSA_PublicKey& dsa,
                                  const std::string& emsa) :
          PK_Ops::Verification_with_EMSA(emsa),
-         m_q(dsa.group_q()), m_y(dsa.get_y()), m_powermod_g_p{Fixed_Base_Power_Mod(dsa.group_g(), dsa.group_p())},
-         m_powermod_y_p{Fixed_Base_Power_Mod(m_y, dsa.group_p())}, m_mod_p{Modular_Reducer(dsa.group_p())},
-         m_mod_q{Modular_Reducer(dsa.group_q())}
+         m_group(dsa.get_group()),
+         m_y(dsa.get_y()),
+         m_powermod_y_p(m_y, dsa.group_p()),
+         m_mod_q(dsa.group_q())
          {}
 
-      size_t max_input_bits() const override { return m_q.bits(); }
+      size_t max_input_bits() const override { return m_group.get_q().bits(); }
 
       bool with_recovery() const override { return false; }
 
       bool verify(const uint8_t msg[], size_t msg_len,
                   const uint8_t sig[], size_t sig_len) override;
    private:
-      const BigInt& m_q;
+      const DL_Group m_group;
       const BigInt& m_y;
 
-      Fixed_Base_Power_Mod m_powermod_g_p, m_powermod_y_p;
-      Modular_Reducer m_mod_p, m_mod_q;
+      Fixed_Base_Power_Mod m_powermod_y_p;
+      Modular_Reducer m_mod_q;
    };
 
 bool DSA_Verification_Operation::verify(const uint8_t msg[], size_t msg_len,
                                         const uint8_t sig[], size_t sig_len)
    {
-   if(sig_len != 2*m_q.bytes() || msg_len > m_q.bytes())
+   const BigInt& q = m_group.get_q();
+   const size_t q_bytes = q.bytes();
+
+   if(sig_len != 2*q_bytes || msg_len > q_bytes)
       return false;
 
-   BigInt r(sig, m_q.bytes());
-   BigInt s(sig + m_q.bytes(), m_q.bytes());
+   BigInt r(sig, q_bytes);
+   BigInt s(sig + q_bytes, q_bytes);
    BigInt i(msg, msg_len);
 
-   if(r <= 0 || r >= m_q || s <= 0 || s >= m_q)
+   if(r <= 0 || r >= q || s <= 0 || s >= q)
       return false;
 
-   s = inverse_mod(s, m_q);
+   s = inverse_mod(s, q);
 
 #if defined(BOTAN_TARGET_OS_HAS_THREADS)
    auto future_s_i = std::async(std::launch::async,
-      [&]() { return m_powermod_g_p(m_mod_q.multiply(s, i)); });
+                                [&]() { return m_group.power_g_p(m_mod_q.multiply(s, i)); });
 
    BigInt s_r = m_powermod_y_p(m_mod_q.multiply(s, r));
    BigInt s_i = future_s_i.get();
 #else
    BigInt s_r = m_powermod_y_p(m_mod_q.multiply(s, r));
-   BigInt s_i = m_powermod_g_p(m_mod_q.multiply(s, i));
+   BigInt s_i = m_group.power_g_p(m_mod_q.multiply(s, i));
 #endif
 
-   s = m_mod_p.multiply(s_i, s_r);
+   s = m_group.multiply_mod_p(s_i, s_r);
 
    return (m_mod_q.reduce(s) == r);
    }
diff --git a/src/lib/pubkey/ec_group/ec_group.cpp b/src/lib/pubkey/ec_group/ec_group.cpp
index 4123994b5..771bd4b0f 100644
--- a/src/lib/pubkey/ec_group/ec_group.cpp
+++ b/src/lib/pubkey/ec_group/ec_group.cpp
@@ -188,11 +188,6 @@ EC_Group_Data_Map& EC_Group::ec_group_data()
    * This exists purely to ensure the allocator is constructed before g_ec_data,
    * which ensures that its destructor runs after ~g_ec_data is complete.
    */
-   class Allocator_Initializer
-      {
-      public:
-         Allocator_Initializer() { initialize_allocator(); }
-      };
 
    static Allocator_Initializer g_init_allocator;
    static EC_Group_Data_Map g_ec_data;
diff --git a/src/lib/pubkey/elgamal/elgamal.cpp b/src/lib/pubkey/elgamal/elgamal.cpp
index a44f352f5..3a5d8b81e 100644
--- a/src/lib/pubkey/elgamal/elgamal.cpp
+++ b/src/lib/pubkey/elgamal/elgamal.cpp
@@ -1,6 +1,6 @@
 /*
 * ElGamal
-* (C) 1999-2007 Jack Lloyd
+* (C) 1999-2007,2018 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
@@ -18,33 +18,34 @@ namespace Botan {
 /*
 * ElGamal_PublicKey Constructor
 */
-ElGamal_PublicKey::ElGamal_PublicKey(const DL_Group& grp, const BigInt& y1)
+ElGamal_PublicKey::ElGamal_PublicKey(const DL_Group& group, const BigInt& y) :
+   DL_Scheme_PublicKey(group, y)
    {
-   m_group = grp;
-   m_y = y1;
    }
 
 /*
 * ElGamal_PrivateKey Constructor
 */
 ElGamal_PrivateKey::ElGamal_PrivateKey(RandomNumberGenerator& rng,
-                                       const DL_Group& grp,
-                                       const BigInt& x_arg)
+                                       const DL_Group& group,
+                                       const BigInt& x)
    {
-   m_group = grp;
-   m_x = x_arg;
+   m_x = x;
+   m_group = group;
 
-   if(m_x == 0)
+   if(m_x.is_zero())
+      {
       m_x.randomize(rng, dl_exponent_size(group_p().bits()));
+      }
 
-   m_y = power_mod(group_g(), m_x, group_p());
+   m_y = m_group.power_g_p(m_x);
    }
 
 ElGamal_PrivateKey::ElGamal_PrivateKey(const AlgorithmIdentifier& alg_id,
                                        const secure_vector<uint8_t>& key_bits) :
    DL_Scheme_PrivateKey(alg_id, key_bits, DL_Group::ANSI_X9_42)
    {
-   m_y = power_mod(group_g(), m_x, group_p());
+   m_y = m_group.power_g_p(m_x);
    }
 
 /*
@@ -71,7 +72,7 @@ class ElGamal_Encryption_Operation final : public PK_Ops::Encryption_with_EME
    {
    public:
 
-      size_t max_raw_input_bits() const override { return m_mod_p.get_modulus().bits() - 1; }
+      size_t max_raw_input_bits() const override { return m_group.p_bits() - 1; }
 
       ElGamal_Encryption_Operation(const ElGamal_PublicKey& key, const std::string& eme);
 
@@ -79,41 +80,34 @@ class ElGamal_Encryption_Operation final : public PK_Ops::Encryption_with_EME
                                       RandomNumberGenerator& rng) override;
 
    private:
-      Fixed_Base_Power_Mod m_powermod_g_p, m_powermod_y_p;
-      Modular_Reducer m_mod_p;
+      const DL_Group m_group;
+      Fixed_Base_Power_Mod m_powermod_y_p;
    };
 
 ElGamal_Encryption_Operation::ElGamal_Encryption_Operation(const ElGamal_PublicKey& key,
                                                            const std::string& eme) :
-   PK_Ops::Encryption_with_EME(eme)
+   PK_Ops::Encryption_with_EME(eme),
+   m_group(key.get_group()),
+   m_powermod_y_p(key.get_y(), m_group.get_p())
    {
-   const BigInt& p = key.group_p();
-
-   m_powermod_g_p = Fixed_Base_Power_Mod(key.group_g(), p);
-   m_powermod_y_p = Fixed_Base_Power_Mod(key.get_y(), p);
-   m_mod_p = Modular_Reducer(p);
    }
 
 secure_vector<uint8_t>
 ElGamal_Encryption_Operation::raw_encrypt(const uint8_t msg[], size_t msg_len,
                                           RandomNumberGenerator& rng)
    {
-   const BigInt& p = m_mod_p.get_modulus();
-
    BigInt m(msg, msg_len);
 
-   if(m >= p)
+   if(m >= m_group.get_p())
       throw Invalid_Argument("ElGamal encryption: Input is too large");
 
-   BigInt k(rng, dl_exponent_size(p.bits()));
+   const size_t k_bits = dl_exponent_size(m_group.p_bits());
+   const BigInt k(rng, k_bits);
 
-   BigInt a = m_powermod_g_p(k);
-   BigInt b = m_mod_p.multiply(m, m_powermod_y_p(k));
+   const BigInt a = m_group.power_g_p(k);
+   const BigInt b = m_group.multiply_mod_p(m, m_powermod_y_p(k));
 
-   secure_vector<uint8_t> output(2*p.bytes());
-   a.binary_encode(&output[p.bytes() - a.bytes()]);
-   b.binary_encode(&output[output.size() / 2 + (p.bytes() - b.bytes())]);
-   return output;
+   return BigInt::encode_fixed_length_int_pair(a, b, m_group.p_bytes());
    }
 
 /**
@@ -123,8 +117,7 @@ class ElGamal_Decryption_Operation final : public PK_Ops::Decryption_with_EME
    {
    public:
 
-      size_t max_raw_input_bits() const override
-         { return m_mod_p.get_modulus().bits() - 1; }
+      size_t max_raw_input_bits() const override { return m_group.p_bits() - 1; }
 
       ElGamal_Decryption_Operation(const ElGamal_PrivateKey& key,
                                    const std::string& eme,
@@ -132,8 +125,8 @@ class ElGamal_Decryption_Operation final : public PK_Ops::Decryption_with_EME
 
       secure_vector<uint8_t> raw_decrypt(const uint8_t msg[], size_t msg_len) override;
    private:
+      const DL_Group m_group;
       Fixed_Exponent_Power_Mod m_powermod_x_p;
-      Modular_Reducer m_mod_p;
       Blinder m_blinder;
    };
 
@@ -141,9 +134,9 @@ ElGamal_Decryption_Operation::ElGamal_Decryption_Operation(const ElGamal_Private
                                                            const std::string& eme,
                                                            RandomNumberGenerator& rng) :
    PK_Ops::Decryption_with_EME(eme),
-   m_powermod_x_p(Fixed_Exponent_Power_Mod(key.get_x(), key.group_p())),
-   m_mod_p(Modular_Reducer(key.group_p())),
-   m_blinder(key.group_p(),
+   m_group(key.get_group()),
+   m_powermod_x_p(key.get_x(), m_group.get_p()),
+   m_blinder(m_group.get_p(),
              rng,
              [](const BigInt& k) { return k; },
              [this](const BigInt& k) { return m_powermod_x_p(k); })
@@ -153,22 +146,20 @@ ElGamal_Decryption_Operation::ElGamal_Decryption_Operation(const ElGamal_Private
 secure_vector<uint8_t>
 ElGamal_Decryption_Operation::raw_decrypt(const uint8_t msg[], size_t msg_len)
    {
-   const BigInt& p = m_mod_p.get_modulus();
-
-   const size_t p_bytes = p.bytes();
+   const size_t p_bytes = m_group.p_bytes();
 
    if(msg_len != 2 * p_bytes)
       throw Invalid_Argument("ElGamal decryption: Invalid message");
 
    BigInt a(msg, p_bytes);
-   BigInt b(msg + p_bytes, p_bytes);
+   const BigInt b(msg + p_bytes, p_bytes);
 
-   if(a >= p || b >= p)
+   if(a >= m_group.get_p() || b >= m_group.get_p())
       throw Invalid_Argument("ElGamal decryption: Invalid message");
 
    a = m_blinder.blind(a);
 
-   BigInt r = m_mod_p.multiply(b, inverse_mod(m_powermod_x_p(a), p));
+   const BigInt r = m_group.multiply_mod_p(m_group.inverse_mod_p(m_powermod_x_p(a)), b);
 
    return BigInt::encode_1363(m_blinder.unblind(r), p_bytes);
    }
diff --git a/src/lib/pubkey/rsa/rsa.cpp b/src/lib/pubkey/rsa/rsa.cpp
index cfb1ae7ba..1ba4d6b25 100644
--- a/src/lib/pubkey/rsa/rsa.cpp
+++ b/src/lib/pubkey/rsa/rsa.cpp
@@ -219,7 +219,7 @@ class RSA_Private_Operation
       BigInt private_op(const BigInt& m) const
          {
 #if defined(BOTAN_TARGET_OS_HAS_THREADS)
-         auto future_j1 = std::async(std::launch::async, m_powermod_d1_p, m);
+         auto future_j1 = std::async(std::launch::async, std::ref(m_powermod_d1_p), m);
          BigInt j2 = m_powermod_d2_q(m);
          BigInt j1 = future_j1.get();
 #else
diff --git a/src/lib/utils/mem_ops.h b/src/lib/utils/mem_ops.h
index 5fb5752fc..c59c02d5a 100644
--- a/src/lib/utils/mem_ops.h
+++ b/src/lib/utils/mem_ops.h
@@ -37,6 +37,12 @@ BOTAN_PUBLIC_API(2,3) void deallocate_memory(void* p, size_t elems, size_t elem_
 */
 void initialize_allocator();
 
+class Allocator_Initializer
+   {
+   public:
+      Allocator_Initializer() { initialize_allocator(); }
+   };
+
 /**
 * Scrub memory contents in a way that a compiler should not elide,
 * using some system specific technique. Note that this function might