Add dh functions in ffi

4 files changed, 240 insertions, 8 deletions

diff --git a/doc/manual/ffi.rst b/doc/manual/ffi.rst
index 89e075885..db3bd8d53 100644
--- a/doc/manual/ffi.rst
+++ b/doc/manual/ffi.rst
@@ -492,6 +492,8 @@ Public Key Creation, Import and Export
 
 .. cpp:function:: int botan_privkey_create_mceliece(botan_privkey_t* key, botan_rng_t rng, size_t n, size_t t)
 
+.. cpp:function:: int botan_privkey_create_dh(botan_privkey_t* key, botan_rng_t rng, const char* params)
+
 .. cpp:function:: int botan_privkey_load(botan_privkey_t* key, botan_rng_t rng, \
                                  const uint8_t bits[], size_t len, \
                                  const char* password)
@@ -638,7 +640,20 @@ ElGamal specific functions
 .. cpp:function:: int botan_pubkey_load_elgamal(botan_pubkey_t* key, \
                                      botan_mp_t p, botan_mp_t g, botan_mp_t y)
 
-   Initialize a private ElGamal key using group parameters p and g and public key y.
+   Initialize a public ElGamal key using group parameters p and g and public key y.
+
+Diffie Hellmann specific functions
+----------------------------------------
+
+.. cpp:function:: int botan_privkey_load_dh(botan_privkey_t* key, \
+                                     botan_mp_t p, botan_mp_t g, botan_mp_t x)
+
+   Initialize a private Diffie Hellmann key using group parameters p and g and private key x.
+
+.. cpp:function:: int botan_pubkey_load_dh(botan_pubkey_t* key, \
+                                     botan_mp_t p, botan_mp_t g, botan_mp_t y)
+
+   Initialize a public Diffie Hellmann key using group parameters p and g and public key y.
 
 Public Key Encryption/Decryption
 ----------------------------------------
diff --git a/src/lib/ffi/ffi.h b/src/lib/ffi/ffi.h
index f59da0545..565d5ce7b 100644
--- a/src/lib/ffi/ffi.h
+++ b/src/lib/ffi/ffi.h
@@ -693,6 +693,7 @@ BOTAN_DLL int botan_privkey_create_rsa(botan_privkey_t* key, botan_rng_t rng, si
 BOTAN_DLL int botan_privkey_create_ecdsa(botan_privkey_t* key, botan_rng_t rng, const char* params);
 BOTAN_DLL int botan_privkey_create_ecdh(botan_privkey_t* key, botan_rng_t rng, const char* params);
 BOTAN_DLL int botan_privkey_create_mceliece(botan_privkey_t* key, botan_rng_t rng, size_t n, size_t t);
+BOTAN_DLL int botan_privkey_create_dh(botan_privkey_t* key, botan_rng_t rng, const char* param);
 
 /*
 * Input currently assumed to be PKCS #8 structure;
@@ -832,6 +833,41 @@ BOTAN_DLL int botan_pubkey_dsa_get_g(botan_mp_t d, botan_pubkey_t key);
 BOTAN_DLL int botan_pubkey_dsa_get_y(botan_mp_t y, botan_pubkey_t key);
 
 /*
+* Loads Diffie Hellman private key
+*
+* @param key variable populated with key material
+* @param p prime order of a Z_p group
+* @param g group generator
+* @param x private key
+*
+* @pre key is NULL on input
+* @post function allocates memory and assigns to `key'
+*
+* @return 0 on success, a negative value on failure
+*/
+BOTAN_DLL int botan_privkey_load_dh(botan_privkey_t* key,
+                                         botan_mp_t p,
+                                         botan_mp_t g,
+                                         botan_mp_t x);
+/*
+* Loads Diffie Hellman public key
+*
+* @param key variable populated with key material
+* @param p prime order of a Z_p group
+* @param g group generator
+* @param y public key
+*
+* @pre key is NULL on input
+* @post function allocates memory and assigns to `key'
+*
+* @return 0 on success, a negative value on failure
+*/
+BOTAN_DLL int botan_pubkey_load_dh(botan_pubkey_t* key,
+                                        botan_mp_t p,
+                                        botan_mp_t g,
+                                        botan_mp_t y);
+
+/*
 * Algorithm specific key operations: ElGamal
 */
 
diff --git a/src/lib/ffi/ffi_pkey_algs.cpp b/src/lib/ffi/ffi_pkey_algs.cpp
index 844a38846..bde673487 100644
--- a/src/lib/ffi/ffi_pkey_algs.cpp
+++ b/src/lib/ffi/ffi_pkey_algs.cpp
@@ -60,6 +60,11 @@
   #include <botan/mceies.h>
 #endif
 
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+  #include <botan/dh.h>
+#endif
+
+
 namespace {
 
 #if defined(BOTAN_HAS_ECC_PUBLIC_KEY_CRYPTO)
@@ -496,6 +501,61 @@ int botan_privkey_load_elgamal(botan_privkey_t* key,
 #endif
    }
 
+/* Diffie Hellman specific operations */
+
+int botan_privkey_create_dh(botan_privkey_t* key_obj, botan_rng_t rng_obj, const char* param_str)
+   {
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+   return ffi_guard_thunk(BOTAN_CURRENT_FUNCTION, [=]() {
+      if(key_obj == nullptr || rng_obj == nullptr || param_str == nullptr || *param_str == 0)
+         return BOTAN_FFI_ERROR_NULL_POINTER;
+
+      *key_obj = nullptr;
+
+      Botan::RandomNumberGenerator& rng = safe_get(rng_obj);
+      Botan::DL_Group grp(param_str);
+      *key_obj = new botan_privkey_struct(new Botan::DH_PrivateKey(rng, grp, 0));
+      return BOTAN_FFI_SUCCESS;
+      });
+#else
+   BOTAN_UNUSED(key_obj, rng_obj, param_str);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+   }
+
+int botan_privkey_load_dh(botan_privkey_t* key,
+                               botan_mp_t p, botan_mp_t g, botan_mp_t x)
+   {
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+   *key = nullptr;
+   return ffi_guard_thunk(BOTAN_CURRENT_FUNCTION, [=]() {
+      Botan::Null_RNG null_rng;
+      Botan::DL_Group group(safe_get(p), safe_get(g));
+      *key = new botan_privkey_struct(new Botan::DH_PrivateKey(null_rng, group, safe_get(x)));
+      return BOTAN_FFI_SUCCESS;
+      });
+#else
+   BOTAN_UNUSED(key, p, g, x);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+   }
+
+int botan_pubkey_load_dh(botan_pubkey_t* key,
+                              botan_mp_t p, botan_mp_t g, botan_mp_t y)
+   {
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+   *key = nullptr;
+   return ffi_guard_thunk(BOTAN_CURRENT_FUNCTION, [=]() {
+      Botan::DL_Group group(safe_get(p), safe_get(g));
+      *key = new botan_pubkey_struct(new Botan::DH_PublicKey(group, safe_get(y)));
+      return BOTAN_FFI_SUCCESS;
+      });
+#else
+   BOTAN_UNUSED(key, p, g, y);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+   }
+
 /* ECDH + x25519 specific operations */
 
 int botan_privkey_create_ecdh(botan_privkey_t* key_obj, botan_rng_t rng_obj, const char* param_str)
diff --git a/src/tests/test_ffi.cpp b/src/tests/test_ffi.cpp
index 34d832026..95fb75831 100644
--- a/src/tests/test_ffi.cpp
+++ b/src/tests/test_ffi.cpp
@@ -402,6 +402,10 @@ class FFI_Unit_Tests : public Test
          results.push_back(ffi_test_elgamal(rng));
 #endif
 
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+         results.push_back(ffi_test_dh(rng));
+#endif
+
 #if defined(BOTAN_HAS_ED25519)
          results.push_back(ffi_test_ed25519(rng));
 #endif
@@ -1588,15 +1592,14 @@ class FFI_Unit_Tests : public Test
          botan_pk_op_ka_t ka2;
          REQUIRE_FFI_OK(botan_pk_op_key_agreement_create, (&ka2, priv2, "KDF2(SHA-256)", 0));
 
-         std::vector<uint8_t> pubkey1(256); // length problem again
-         size_t pubkey1_len = pubkey1.size();
+         size_t pubkey1_len = 0;
+         TEST_FFI_RC(BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE, botan_pk_op_key_agreement_export_public, (priv1, nullptr, &pubkey1_len));
+         std::vector<uint8_t> pubkey1(pubkey1_len);
          REQUIRE_FFI_OK(botan_pk_op_key_agreement_export_public, (priv1, pubkey1.data(), &pubkey1_len));
-         pubkey1.resize(pubkey1_len);
-
-         std::vector<uint8_t> pubkey2(256); // length problem again
-         size_t pubkey2_len = pubkey2.size();
+         size_t pubkey2_len = 0;
+         TEST_FFI_RC(BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE, botan_pk_op_key_agreement_export_public, (priv2, nullptr, &pubkey2_len));
+         std::vector<uint8_t> pubkey2(pubkey2_len);
          REQUIRE_FFI_OK(botan_pk_op_key_agreement_export_public, (priv2, pubkey2.data(), &pubkey2_len));
-         pubkey2.resize(pubkey2_len);
 
          std::vector<uint8_t> salt(32);
          TEST_FFI_OK(botan_rng_get, (rng, salt.data(), salt.size()));
@@ -1824,6 +1827,124 @@ class FFI_Unit_Tests : public Test
          }
 
 
+      Test::Result ffi_test_dh(botan_rng_t rng)
+         {
+         Test::Result result("FFI DH");
+
+            botan_mp_t private_x, public_g, public_p, public_y;
+
+            botan_privkey_t loaded_privkey1;
+            botan_pubkey_t loaded_pubkey1;
+
+            botan_mp_init(&private_x);
+
+            botan_mp_init(&public_g);
+            botan_mp_init(&public_p);
+            botan_mp_init(&public_y);
+
+            botan_privkey_t priv1;
+            REQUIRE_FFI_OK(botan_privkey_create_dh, (&priv1, rng, "modp/ietf/2048"));
+
+            botan_privkey_t priv2;
+            REQUIRE_FFI_OK(botan_privkey_create_dh, (&priv2, rng, "modp/ietf/2048"));
+
+            botan_pubkey_t pub1;
+            REQUIRE_FFI_OK(botan_privkey_export_pubkey, (&pub1, priv1));
+
+            botan_pubkey_t pub2;
+            REQUIRE_FFI_OK(botan_privkey_export_pubkey, (&pub2, priv2));
+
+            // Reload key-pair1 in order to test functions for key loading
+            TEST_FFI_OK(botan_privkey_get_field, (private_x, priv1, "x"));
+            TEST_FFI_OK(botan_pubkey_get_field, (public_g, pub1, "g"));
+            TEST_FFI_OK(botan_pubkey_get_field, (public_p, pub1, "p"));
+            TEST_FFI_OK(botan_pubkey_get_field, (public_y, pub1, "y"));
+
+            TEST_FFI_OK(botan_privkey_load_dh, (&loaded_privkey1, public_p, public_g, private_x));
+
+            TEST_FFI_OK(botan_pubkey_load_dh, (&loaded_pubkey1, public_p, public_g, public_y));
+
+            TEST_FFI_OK(botan_privkey_check_key, (loaded_privkey1, rng, 0));
+            TEST_FFI_OK(botan_pubkey_check_key, (loaded_pubkey1, rng, 0));
+
+            botan_mp_t loaded_public_g, loaded_public_p, loaded_public_y;
+            botan_mp_init(&loaded_public_g);
+            botan_mp_init(&loaded_public_p);
+            botan_mp_init(&loaded_public_y);
+
+            TEST_FFI_OK(botan_pubkey_get_field, (loaded_public_g, loaded_pubkey1, "g"));
+            TEST_FFI_OK(botan_pubkey_get_field, (loaded_public_p, loaded_pubkey1, "p"));
+            TEST_FFI_OK(botan_pubkey_get_field, (loaded_public_y, loaded_pubkey1, "y"));
+
+            int cmp;
+
+            TEST_FFI_OK(botan_mp_cmp, (&cmp, loaded_public_g, public_g));
+            result.confirm("bigint_mp_cmp(g, g)", cmp == 0);
+
+            TEST_FFI_OK(botan_mp_cmp, (&cmp, loaded_public_p, public_p));
+            result.confirm("bigint_mp_cmp(p, p)", cmp == 0);
+
+            TEST_FFI_OK(botan_mp_cmp, (&cmp, loaded_public_y, public_y));
+            result.confirm("bigint_mp_cmp(y, y)", cmp == 0);
+
+            botan_pk_op_ka_t ka1;
+            REQUIRE_FFI_OK(botan_pk_op_key_agreement_create, (&ka1, loaded_privkey1, "Raw", 0));
+            botan_pk_op_ka_t ka2;
+            REQUIRE_FFI_OK(botan_pk_op_key_agreement_create, (&ka2, priv2, "Raw", 0));
+
+            size_t pubkey1_len = 0;
+            TEST_FFI_RC(BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE, botan_pk_op_key_agreement_export_public, (priv1, nullptr, &pubkey1_len));
+            std::vector<uint8_t> pubkey1(pubkey1_len);
+            REQUIRE_FFI_OK(botan_pk_op_key_agreement_export_public, (priv1, pubkey1.data(), &pubkey1_len));
+            size_t pubkey2_len = 0;
+            TEST_FFI_RC(BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE, botan_pk_op_key_agreement_export_public, (priv2, nullptr, &pubkey2_len));
+            std::vector<uint8_t> pubkey2(pubkey2_len);
+            REQUIRE_FFI_OK(botan_pk_op_key_agreement_export_public, (priv2, pubkey2.data(), &pubkey2_len));
+
+            std::vector<uint8_t> salt(32);
+
+            TEST_FFI_OK(botan_rng_get, (rng, salt.data(), salt.size()));
+
+            const size_t shared_key_len = 256;
+
+            std::vector<uint8_t> key1(shared_key_len);
+            size_t key1_len = key1.size();
+
+            TEST_FFI_OK(botan_pk_op_key_agreement, (ka1, key1.data(), &key1_len,
+                                                    pubkey2.data(), pubkey2.size(),
+                                                    salt.data(), salt.size()));
+
+            std::vector<uint8_t> key2(shared_key_len);
+            size_t key2_len = key2.size();
+
+            TEST_FFI_OK(botan_pk_op_key_agreement, (ka2, key2.data(), &key2_len,
+                                                    pubkey1.data(), pubkey1.size(),
+                                                    salt.data(), salt.size()));
+
+            result.test_eq("shared DH key", key1, key2);
+
+            TEST_FFI_OK(botan_mp_destroy, (private_x));
+            TEST_FFI_OK(botan_mp_destroy, (public_p));
+            TEST_FFI_OK(botan_mp_destroy, (public_g));
+            TEST_FFI_OK(botan_mp_destroy, (public_y));
+
+            TEST_FFI_OK(botan_mp_destroy, (loaded_public_p));
+            TEST_FFI_OK(botan_mp_destroy, (loaded_public_g));
+            TEST_FFI_OK(botan_mp_destroy, (loaded_public_y));
+
+            TEST_FFI_OK(botan_pk_op_key_agreement_destroy, (ka1));
+            TEST_FFI_OK(botan_pk_op_key_agreement_destroy, (ka2));
+            TEST_FFI_OK(botan_privkey_destroy, (priv1));
+            TEST_FFI_OK(botan_privkey_destroy, (priv2));
+            TEST_FFI_OK(botan_pubkey_destroy, (pub1));
+            TEST_FFI_OK(botan_pubkey_destroy, (pub2));
+            TEST_FFI_OK(botan_privkey_destroy, (loaded_privkey1));
+            TEST_FFI_OK(botan_pubkey_destroy, (loaded_pubkey1));
+
+         return result;
+         }
+
+
    };
 
 BOTAN_REGISTER_TEST("ffi", FFI_Unit_Tests);