Remove Algo_Registry usage from public key code.

Instead the key types exposes operations like `create_encryption_op`
which will return the relevant operation if the algorithm supports it.

Changes pubkey.h interface, now RNG is passed at init time.
Blinder previous created its own RNG, now it takes it from app.

2 files changed, 36 insertions, 8 deletions

diff --git a/src/lib/pubkey/elgamal/elgamal.cpp b/src/lib/pubkey/elgamal/elgamal.cpp
index 37dfe89cf..fbbd09226 100644
--- a/src/lib/pubkey/elgamal/elgamal.cpp
+++ b/src/lib/pubkey/elgamal/elgamal.cpp
@@ -5,8 +5,8 @@
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
-#include <botan/internal/pk_utils.h>
 #include <botan/elgamal.h>
+#include <botan/internal/pk_ops_impl.h>
 #include <botan/keypair.h>
 #include <botan/reducer.h>
 #include <botan/blinding.h>
@@ -134,7 +134,9 @@ class ElGamal_Decryption_Operation : public PK_Ops::Decryption_with_EME
       size_t max_raw_input_bits() const override
          { return m_mod_p.get_modulus().bits() - 1; }
 
-      ElGamal_Decryption_Operation(const ElGamal_PrivateKey& key, const std::string& eme);
+      ElGamal_Decryption_Operation(const ElGamal_PrivateKey& key,
+                                   const std::string& eme,
+                                   RandomNumberGenerator& rng);
 
       secure_vector<byte> raw_decrypt(const byte msg[], size_t msg_len) override;
    private:
@@ -144,13 +146,15 @@ class ElGamal_Decryption_Operation : public PK_Ops::Decryption_with_EME
    };
 
 ElGamal_Decryption_Operation::ElGamal_Decryption_Operation(const ElGamal_PrivateKey& key,
-                                                           const std::string& eme) :
+                                                           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(),
-           [](const BigInt& k) { return k; },
-           [this](const BigInt& k) { return m_powermod_x_p(k); })
+             rng,
+             [](const BigInt& k) { return k; },
+             [this](const BigInt& k) { return m_powermod_x_p(k); })
    {
    }
 
@@ -177,9 +181,22 @@ ElGamal_Decryption_Operation::raw_decrypt(const byte msg[], size_t msg_len)
    return BigInt::encode_1363(m_blinder.unblind(r), p_bytes);
    }
 
-BOTAN_REGISTER_PK_ENCRYPTION_OP("ElGamal", ElGamal_Encryption_Operation);
-BOTAN_REGISTER_PK_DECRYPTION_OP("ElGamal", ElGamal_Decryption_Operation);
-
 }
 
+std::unique_ptr<PK_Ops::Encryption>
+ElGamal_PublicKey::create_encryption_op(RandomNumberGenerator& /*rng*/,
+                                        const std::string& params,
+                                        const std::string& /*provider*/) const
+   {
+   return std::unique_ptr<PK_Ops::Encryption>(new ElGamal_Encryption_Operation(*this, params));
+   }
+
+std::unique_ptr<PK_Ops::Decryption>
+ElGamal_PrivateKey::create_decryption_op(RandomNumberGenerator& rng,
+                                         const std::string& params,
+                                         const std::string& /*provider*/) const
+   {
+   return std::unique_ptr<PK_Ops::Decryption>(new ElGamal_Decryption_Operation(*this, params, rng));
+   }
+
 }
diff --git a/src/lib/pubkey/elgamal/elgamal.h b/src/lib/pubkey/elgamal/elgamal.h
index 9f287158d..8ca4facc2 100644
--- a/src/lib/pubkey/elgamal/elgamal.h
+++ b/src/lib/pubkey/elgamal/elgamal.h
@@ -29,6 +29,12 @@ class BOTAN_DLL ElGamal_PublicKey : public virtual DL_Scheme_PublicKey
          {}
 
       ElGamal_PublicKey(const DL_Group& group, const BigInt& y);
+
+      std::unique_ptr<PK_Ops::Encryption>
+         create_encryption_op(RandomNumberGenerator& rng,
+                              const std::string& params,
+                              const std::string& provider) const override;
+
    protected:
       ElGamal_PublicKey() {}
    };
@@ -49,6 +55,11 @@ class BOTAN_DLL ElGamal_PrivateKey : public ElGamal_PublicKey,
       ElGamal_PrivateKey(RandomNumberGenerator& rng,
                          const DL_Group& group,
                          const BigInt& priv_key = 0);
+
+      std::unique_ptr<PK_Ops::Decryption>
+         create_decryption_op(RandomNumberGenerator& rng,
+                              const std::string& params,
+                              const std::string& provider) const override;
    };
 
 }