Merge GH #1074 Add ability to load ECDSA/ECDH via FFI

2 files changed, 175 insertions, 1 deletions

diff --git a/src/lib/ffi/ffi.cpp b/src/lib/ffi/ffi.cpp
index d7f164b86..f46d7ec11 100644
--- a/src/lib/ffi/ffi.cpp
+++ b/src/lib/ffi/ffi.cpp
@@ -330,7 +330,59 @@ Botan::BigInt privkey_get_field(const Botan::Private_Key& key,
    throw Botan::Exception("Unsupported algorithm type for botan_privkey_get_field");
    }
 
-}
+#if defined(BOTAN_HAS_ECDSA) || defined(BOTAN_HAS_ECDH)
+template<class ECPrivateKey_t>
+int privkey_load_ec(std::unique_ptr<ECPrivateKey_t>& key,
+                    const Botan::BigInt& scalar,
+                    const char* curve_name)
+   {
+
+   if(curve_name == nullptr)
+      return -1;
+
+   try
+      {
+      Botan::Null_RNG null_rng;
+      Botan::EC_Group grp(curve_name);
+      key.reset(new ECPrivateKey_t(null_rng, grp, scalar));
+      return 0;
+      }
+   catch(std::exception& e)
+      {
+      log_exception(BOTAN_CURRENT_FUNCTION, e.what());
+      }
+   return -1;
+   }
+#endif
+
+#if defined(BOTAN_HAS_ECDSA) || defined(BOTAN_HAS_ECDH)
+template<class ECPublicKey_t>
+int pubkey_load_ec( std::unique_ptr<ECPublicKey_t>& key,
+                    const Botan::BigInt& public_x,
+                    const Botan::BigInt& public_y,
+                    const char* curve_name)
+   {
+
+   if(curve_name == nullptr)
+      return -1;
+
+   try
+      {
+      Botan::Null_RNG null_rng;
+      Botan::EC_Group grp(curve_name);
+      Botan::PointGFp uncompressed_point(grp.get_curve(), public_x, public_y);
+      key.reset(new ECPublicKey_t(grp, uncompressed_point));
+      return 0;
+      }
+   catch(std::exception& e)
+      {
+      log_exception(BOTAN_CURRENT_FUNCTION, e.what());
+      }
+   return -1;
+   }
+#endif
+
+} // closes anonymous namespace
 
 extern "C" {
 
@@ -1699,6 +1751,107 @@ int botan_pubkey_ed25519_get_pubkey(botan_pubkey_t key,
 #endif
    }
 
+int botan_pubkey_load_ecdsa(botan_pubkey_t* key,
+                                   const botan_mp_t public_x,
+                                   const botan_mp_t public_y,
+                                   const char* curve_name)
+   {
+#if defined(BOTAN_HAS_ECDSA)
+   std::unique_ptr<Botan::ECDSA_PublicKey> p_key;
+   try
+      {
+      if(!pubkey_load_ec(p_key, safe_get(public_x), safe_get(public_y), curve_name))
+         {
+         *key = new botan_pubkey_struct(p_key.release());
+         return 0;
+         }
+      }
+   catch(std::exception& exn)
+      {
+      log_exception(BOTAN_CURRENT_FUNCTION, exn.what());
+      }
+   return -1;
+#else
+   BOTAN_UNUSED(key, public_x, public_y, curve_name);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+   }
+
+int botan_pubkey_load_ecdh(botan_pubkey_t* key,
+                                   const botan_mp_t public_x,
+                                   const botan_mp_t public_y,
+                                   const char* curve_name)
+   {
+#if defined(BOTAN_HAS_ECDH)
+   std::unique_ptr<Botan::ECDH_PublicKey> p_key;
+   try
+      {
+      if(!pubkey_load_ec(p_key, safe_get(public_x), safe_get(public_y), curve_name))
+         {
+         *key = new botan_pubkey_struct(p_key.release());
+         return 0;
+         }
+      }
+   catch(std::exception& exn)
+      {
+      log_exception(BOTAN_CURRENT_FUNCTION, exn.what());
+      }
+   return -1;
+#else
+   BOTAN_UNUSED(key, public_x, public_y, curve_name);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+   }
+
+int botan_privkey_load_ecdsa(botan_privkey_t* key,
+                          const botan_mp_t scalar,
+                          const char* curve_name)
+   {
+#if defined(BOTAN_HAS_ECDSA)
+   std::unique_ptr<Botan::ECDSA_PrivateKey> p_key;
+   try
+      {
+      if(!privkey_load_ec(p_key, safe_get(scalar), curve_name))
+         {
+         *key = new botan_privkey_struct(p_key.release());
+         return 0;
+         }
+      }
+   catch(std::exception& exn)
+      {
+      log_exception(BOTAN_CURRENT_FUNCTION, exn.what());
+      }
+   return -1;
+#else
+   BOTAN_UNUSED(key, scalar, curve_name);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+   }
+int botan_privkey_load_ecdh(botan_privkey_t* key,
+                          const botan_mp_t scalar,
+                          const char* curve_name)
+   {
+#if defined(BOTAN_HAS_ECDH)
+   std::unique_ptr<Botan::ECDH_PrivateKey> p_key;
+   try
+      {
+      if(!privkey_load_ec(p_key, safe_get(scalar), curve_name))
+         {
+         *key = new botan_privkey_struct(p_key.release());
+         return 0;
+         }
+      }
+   catch(std::exception& exn)
+      {
+      log_exception(BOTAN_CURRENT_FUNCTION, exn.what());
+      }
+   return -1;
+#else
+   BOTAN_UNUSED(key, scalar, curve_name);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+   }
+
 int botan_pubkey_get_field(botan_mp_t output,
                            botan_pubkey_t key,
                            const char* field_name_cstr)
diff --git a/src/lib/ffi/ffi.h b/src/lib/ffi/ffi.h
index 3e64c69cd..a179e5fa4 100644
--- a/src/lib/ffi/ffi.h
+++ b/src/lib/ffi/ffi.h
@@ -862,6 +862,27 @@ BOTAN_DLL int botan_pubkey_ed25519_get_pubkey(botan_pubkey_t key,
                                               uint8_t pubkey[32]);
 
 /*
+* Algorithm specific key operations: ECDSA and ECDH
+*/
+BOTAN_DLL int botan_privkey_load_ecdsa(botan_privkey_t* key,
+                                    const botan_mp_t scalar,
+                                    const char* curve_name);
+
+BOTAN_DLL int botan_pubkey_load_ecdsa(botan_pubkey_t* key,
+                                   const botan_mp_t public_x,
+                                   const botan_mp_t public_y,
+                                   const char* curve_name);
+
+BOTAN_DLL int botan_pubkey_load_ecdh(botan_pubkey_t* key,
+                                   const botan_mp_t public_x,
+                                   const botan_mp_t public_y,
+                                   const char* curve_name);
+
+BOTAN_DLL int botan_privkey_load_ecdh(botan_privkey_t* key,
+                                    const botan_mp_t scalar,
+                                    const char* curve_name);
+
+/*
 * Public Key Encryption
 */
 typedef struct botan_pk_op_encrypt_struct* botan_pk_op_encrypt_t;