1 files changed, 350 insertions, 0 deletions
diff --git a/src/engine/gnump/gnump_pk.cpp b/src/engine/gnump/gnump_pk.cpp
new file mode 100644
index 000000000..8d003a5d4
--- /dev/null
+++ b/src/engine/gnump/gnump_pk.cpp
@@ -0,0 +1,350 @@
+/*
+* GnuMP PK operations
+* (C) 1999-2010 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/internal/gnump_engine.h>
+#include <botan/internal/gmp_wrap.h>
+#include <gmp.h>
+
+/* GnuMP 5.0 and later have a side-channel resistent powm */
+#if defined(HAVE_MPZ_POWM_SEC)
+   #undef mpz_powm
+   #define mpz_powm mpz_powm_sec
+#endif
+
+#if defined(BOTAN_HAS_RSA)
+  #include <botan/rsa.h>
+#endif
+
+#if defined(BOTAN_HAS_RW)
+  #include <botan/rw.h>
+#endif
+
+#if defined(BOTAN_HAS_DSA)
+  #include <botan/dsa.h>
+#endif
+
+#if defined(BOTAN_HAS_ELGAMAL)
+  #include <botan/elgamal.h>
+#endif
+
+#if defined(BOTAN_HAS_NYBERG_RUEPPEL)
+  #include <botan/nr.h>
+#endif
+
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+  #include <botan/dh.h>
+#endif
+
+namespace Botan {
+
+namespace {
+
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+class GMP_DH_KA_Operation : public PK_Ops::Key_Agreement
+   {
+   public:
+      GMP_DH_KA_Operation(const DH_PrivateKey& dh) :
+         x(dh.get_x()), p(dh.group_p()) {}
+
+      SecureVector<byte> agree(const byte w[], u32bit w_len)
+         {
+         GMP_MPZ z(w, w_len);
+         mpz_powm(z.value, z.value, x.value, p.value);
+         return z.to_bytes();
+         }
+
+   private:
+      GMP_MPZ x, p;
+   };
+#endif
+
+#if defined(BOTAN_HAS_DSA)
+
+class GMP_DSA_Signature_Operation : public PK_Ops::Signature
+   {
+   public:
+      GMP_DSA_Signature_Operation(const DSA_PrivateKey& dsa) :
+         x(dsa.get_x()),
+         p(dsa.group_p()),
+         q(dsa.group_q()),
+         g(dsa.group_g()),
+         q_bits(dsa.group_q().bits()) {}
+
+      u32bit message_parts() const { return 2; }
+      u32bit message_part_size() const { return (q_bits + 7) / 8; }
+      u32bit max_input_bits() const { return q_bits; }
+
+      SecureVector<byte> sign(const byte msg[], u32bit msg_len,
+                              RandomNumberGenerator& rng);
+   private:
+      const GMP_MPZ x, p, q, g;
+      u32bit q_bits;
+   };
+
+SecureVector<byte>
+GMP_DSA_Signature_Operation::sign(const byte msg[], u32bit msg_len,
+                                  RandomNumberGenerator& rng)
+   {
+   const u32bit q_bytes = (q_bits + 7) / 8;
+
+   rng.add_entropy(msg, msg_len);
+
+   BigInt k_bn;
+   do
+      k_bn.randomize(rng, q_bits);
+   while(k_bn >= q.to_bigint());
+
+   GMP_MPZ i(msg, msg_len);
+   GMP_MPZ k(k_bn);
+
+   GMP_MPZ r;
+   mpz_powm(r.value, g.value, k.value, p.value);
+   mpz_mod(r.value, r.value, q.value);
+
+   mpz_invert(k.value, k.value, q.value);
+
+   GMP_MPZ s;
+   mpz_mul(s.value, x.value, r.value);
+   mpz_add(s.value, s.value, i.value);
+   mpz_mul(s.value, s.value, k.value);
+   mpz_mod(s.value, s.value, q.value);
+
+   if(mpz_cmp_ui(r.value, 0) == 0 || mpz_cmp_ui(s.value, 0) == 0)
+      throw Internal_Error("GMP_DSA_Op::sign: r or s was zero");
+
+   SecureVector<byte> output(2*q_bytes);
+   r.encode(output, q_bytes);
+   s.encode(output + q_bytes, q_bytes);
+   return output;
+   }
+
+class GMP_DSA_Verification_Operation : public PK_Ops::Verification
+   {
+   public:
+      GMP_DSA_Verification_Operation(const DSA_PublicKey& dsa) :
+         y(dsa.get_y()),
+         p(dsa.group_p()),
+         q(dsa.group_q()),
+         g(dsa.group_g()),
+         q_bits(dsa.group_q().bits()) {}
+
+      u32bit message_parts() const { return 2; }
+      u32bit message_part_size() const { return (q_bits + 7) / 8; }
+      u32bit max_input_bits() const { return q_bits; }
+
+      bool with_recovery() const { return false; }
+
+      bool verify(const byte msg[], u32bit msg_len,
+                  const byte sig[], u32bit sig_len);
+   private:
+      const GMP_MPZ y, p, q, g;
+      u32bit q_bits;
+   };
+
+bool GMP_DSA_Verification_Operation::verify(const byte msg[], u32bit msg_len,
+                                            const byte sig[], u32bit sig_len)
+   {
+   const u32bit q_bytes = q.bytes();
+
+   if(sig_len != 2*q_bytes || msg_len > q_bytes)
+      return false;
+
+   GMP_MPZ r(sig, q_bytes);
+   GMP_MPZ s(sig + q_bytes, q_bytes);
+   GMP_MPZ i(msg, msg_len);
+
+   if(mpz_cmp_ui(r.value, 0) <= 0 || mpz_cmp(r.value, q.value) >= 0)
+      return false;
+   if(mpz_cmp_ui(s.value, 0) <= 0 || mpz_cmp(s.value, q.value) >= 0)
+      return false;
+
+   if(mpz_invert(s.value, s.value, q.value) == 0)
+      return false;
+
+   GMP_MPZ si;
+   mpz_mul(si.value, s.value, i.value);
+   mpz_mod(si.value, si.value, q.value);
+   mpz_powm(si.value, g.value, si.value, p.value);
+
+   GMP_MPZ sr;
+   mpz_mul(sr.value, s.value, r.value);
+   mpz_mod(sr.value, sr.value, q.value);
+   mpz_powm(sr.value, y.value, sr.value, p.value);
+
+   mpz_mul(si.value, si.value, sr.value);
+   mpz_mod(si.value, si.value, p.value);
+   mpz_mod(si.value, si.value, q.value);
+
+   if(mpz_cmp(si.value, r.value) == 0)
+      return true;
+   return false;
+   }
+
+#endif
+
+#if defined(BOTAN_HAS_RSA)
+
+class GMP_RSA_Private_Operation : public PK_Ops::Signature,
+                                  public PK_Ops::Decryption
+   {
+   public:
+      GMP_RSA_Private_Operation(const RSA_PrivateKey& rsa) :
+         mod(rsa.get_n()),
+         p(rsa.get_p()),
+         q(rsa.get_q()),
+         d1(rsa.get_d1()),
+         d2(rsa.get_d2()),
+         c(rsa.get_c()),
+         n_bits(rsa.get_n().bits())
+         {}
+
+      u32bit max_input_bits() const { return (n_bits - 1); }
+
+      SecureVector<byte> sign(const byte msg[], u32bit msg_len,
+                              RandomNumberGenerator&)
+         {
+         BigInt m(msg, msg_len);
+         BigInt x = private_op(m);
+         return BigInt::encode_1363(x, (n_bits + 7) / 8);
+         }
+
+      SecureVector<byte> decrypt(const byte msg[], u32bit msg_len)
+         {
+         BigInt m(msg, msg_len);
+         return BigInt::encode(private_op(m));
+         }
+
+   private:
+      BigInt private_op(const BigInt& m) const;
+
+      GMP_MPZ mod, p, q, d1, d2, c;
+      u32bit n_bits;
+   };
+
+BigInt GMP_RSA_Private_Operation::private_op(const BigInt& m) const
+   {
+   GMP_MPZ j1, j2, h(m);
+
+   mpz_powm(j1.value, h.value, d1.value, p.value);
+   mpz_powm(j2.value, h.value, d2.value, q.value);
+   mpz_sub(h.value, j1.value, j2.value);
+   mpz_mul(h.value, h.value, c.value);
+   mpz_mod(h.value, h.value, p.value);
+   mpz_mul(h.value, h.value, q.value);
+   mpz_add(h.value, h.value, j2.value);
+   return h.to_bigint();
+   }
+
+class GMP_RSA_Public_Operation : public PK_Ops::Verification,
+                                 public PK_Ops::Encryption
+   {
+   public:
+      GMP_RSA_Public_Operation(const RSA_PublicKey& rsa) :
+         n(rsa.get_n()), e(rsa.get_e()), mod(rsa.get_n())
+         {}
+
+      u32bit max_input_bits() const { return (n.bits() - 1); }
+      bool with_recovery() const { return true; }
+
+      SecureVector<byte> encrypt(const byte msg[], u32bit msg_len,
+                                 RandomNumberGenerator&)
+         {
+         BigInt m(msg, msg_len);
+         return BigInt::encode_1363(public_op(m), n.bytes());
+         }
+
+      SecureVector<byte> verify_mr(const byte msg[], u32bit msg_len)
+         {
+         BigInt m(msg, msg_len);
+         return BigInt::encode(public_op(m));
+         }
+
+   private:
+      BigInt public_op(const BigInt& m) const
+         {
+         if(m >= n)
+            throw Invalid_Argument("RSA public op - input is too large");
+
+         GMP_MPZ m_gmp(m);
+         mpz_powm(m_gmp.value, m_gmp.value, e.value, mod.value);
+         return m_gmp.to_bigint();
+         }
+
+      const BigInt& n;
+      const GMP_MPZ e, mod;
+   };
+
+#endif
+
+}
+
+PK_Ops::Key_Agreement*
+GMP_Engine::get_key_agreement_op(const Private_Key& key) const
+   {
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+   if(const DH_PrivateKey* dh = dynamic_cast<const DH_PrivateKey*>(&key))
+      return new GMP_DH_KA_Operation(*dh);
+#endif
+
+   return 0;
+   }
+
+PK_Ops::Signature*
+GMP_Engine::get_signature_op(const Private_Key& key) const
+   {
+#if defined(BOTAN_HAS_RSA)
+   if(const RSA_PrivateKey* s = dynamic_cast<const RSA_PrivateKey*>(&key))
+      return new GMP_RSA_Private_Operation(*s);
+#endif
+
+#if defined(BOTAN_HAS_DSA)
+   if(const DSA_PrivateKey* s = dynamic_cast<const DSA_PrivateKey*>(&key))
+      return new GMP_DSA_Signature_Operation(*s);
+#endif
+
+   return 0;
+   }
+
+PK_Ops::Verification*
+GMP_Engine::get_verify_op(const Public_Key& key) const
+   {
+#if defined(BOTAN_HAS_RSA)
+   if(const RSA_PublicKey* s = dynamic_cast<const RSA_PublicKey*>(&key))
+      return new GMP_RSA_Public_Operation(*s);
+#endif
+
+#if defined(BOTAN_HAS_DSA)
+   if(const DSA_PublicKey* s = dynamic_cast<const DSA_PublicKey*>(&key))
+      return new GMP_DSA_Verification_Operation(*s);
+#endif
+
+   return 0;
+   }
+
+PK_Ops::Encryption*
+GMP_Engine::get_encryption_op(const Public_Key& key) const
+   {
+#if defined(BOTAN_HAS_RSA)
+   if(const RSA_PublicKey* s = dynamic_cast<const RSA_PublicKey*>(&key))
+      return new GMP_RSA_Public_Operation(*s);
+#endif
+
+   return 0;
+   }
+
+PK_Ops::Decryption*
+GMP_Engine::get_decryption_op(const Private_Key& key) const
+   {
+#if defined(BOTAN_HAS_RSA)
+   if(const RSA_PrivateKey* s = dynamic_cast<const RSA_PrivateKey*>(&key))
+      return new GMP_RSA_Private_Operation(*s);
+#endif
+
+   return 0;
+   }
+
+}