Change yaca_key_derive_kdf() API

Key material length should be in bytes.
Fix key exchange example.

Change-Id: I6b408a45d963d806f9abbb50056ed08da3a979fc

diff --git a/api/yaca/yaca_key.h b/api/yaca/yaca_key.h
index 81d0767..8cf4b93 100755 (executable)
--- a/api/yaca/yaca_key.h
+++ b/api/yaca/yaca_key.h
@@ -371,14 +371,14 @@ int yaca_key_derive_dh(const yaca_key_h prv_key,
  *
  * @remarks  The @a key_material should be freed using yaca_free()
  *
- * @param[in]  kdf                    Key derivation function
- * @param[in]  algo                   Digest algorithm that should be used in key derivation
- * @param[in]  secret                 Shared secret
- * @param[in]  secret_len             Size of the shared secret
- * @param[in]  info                   Optional additional info, use NULL if not appending extra info
- * @param[in]  info_len               Length of additional info, use 0 if not using additional info
- * @param[in]  key_material_bit_len   Length of a key material (in bits) to be generated
- * @param[out] key_material           Newly generated key material
+ * @param[in]  kdf               Key derivation function
+ * @param[in]  algo              Digest algorithm that should be used in key derivation
+ * @param[in]  secret            Shared secret
+ * @param[in]  secret_len        Size of the shared secret
+ * @param[in]  info              Optional additional info, use NULL if not appending extra info
+ * @param[in]  info_len          Length of additional info, use 0 if not using additional info
+ * @param[in]  key_material_len  Length of a key material to be generated
+ * @param[out] key_material      Newly generated key material
  *
  * @return #YACA_ERROR_NONE on success, negative on error
  * @retval #YACA_ERROR_NONE Successful
@@ -399,7 +399,7 @@ int yaca_key_derive_kdf(yaca_kdf_e kdf,
                         size_t secret_len,
                         const char *info,
                         size_t info_len,
-                        size_t key_material_bit_len,
+                        size_t key_material_len,
                         char **key_material);
 
 /**

diff --git a/examples/key_exchange.c b/examples/key_exchange.c
index 836cc2a..cc645a9 100644 (file)
--- a/examples/key_exchange.c
+++ b/examples/key_exchange.c
@@ -36,12 +36,18 @@ static yaca_key_h exchange_keys(const yaca_key_h pkey)
        int ret;
        char *secret = NULL;
        size_t secret_len;
+       char *temp_material = NULL;
+       size_t temp_material_len;
        char *key_material = NULL;
+       size_t key_material_len;
+       char *iv_material = NULL;
+       size_t iv_material_len;
 
        yaca_key_h private_key = YACA_KEY_NULL;
        yaca_key_h public_key = YACA_KEY_NULL;
        yaca_key_h params = YACA_KEY_NULL;
        yaca_key_h aes_key = YACA_KEY_NULL;
+       yaca_key_h iv = YACA_KEY_NULL;
 
        ret = yaca_key_extract_parameters(pkey, &params);
        if (ret != YACA_ERROR_NONE)
@@ -60,47 +66,57 @@ static yaca_key_h exchange_keys(const yaca_key_h pkey)
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
+       key_material_len = YACA_KEY_LENGTH_192BIT / 8;
+       iv_material_len = YACA_KEY_LENGTH_IV_128BIT / 8;
+       temp_material_len = key_material_len + iv_material_len;
        ret = yaca_key_derive_kdf(YACA_KDF_X962, YACA_DIGEST_SHA512, secret, secret_len,
-                                 NULL, 0, YACA_KEY_LENGTH_192BIT, &key_material);
+                                 NULL, 0, temp_material_len, &temp_material);
+
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
-       ret = yaca_key_import(YACA_KEY_TYPE_SYMMETRIC, NULL, key_material, YACA_KEY_LENGTH_192BIT,
-                             &aes_key);
+       key_material = temp_material;
+       iv_material = temp_material + key_material_len;
+
+       ret = yaca_key_import(YACA_KEY_TYPE_SYMMETRIC, NULL, key_material, key_material_len, &aes_key);
+       if (ret != YACA_ERROR_NONE)
+               goto exit;
+
+       ret = yaca_key_import(YACA_KEY_TYPE_IV, NULL, iv_material, iv_material_len, &iv);
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
        dump_hex(secret, secret_len, "\n***** Peer Secret: *****");
-       dump_hex(key_material, YACA_KEY_LENGTH_192BIT, "\n***** Peer AES key: *****");
+       dump_hex(key_material, key_material_len, "\n***** Peer AES key: *****");
+       dump_hex(iv_material, iv_material_len, "\n***** Peer IV: *****");
 
 exit:
        yaca_key_destroy(private_key);
        yaca_key_destroy(params);
        yaca_key_destroy(aes_key);
+       yaca_key_destroy(iv);
        yaca_free(secret);
-       yaca_free(key_material);
+       yaca_free(temp_material);
 
        return public_key;
 }
 
-void key_exchange_dh_standard_parameters(void)
+void key_derivation(const yaca_key_h private_key)
 {
        int ret;
        char *secret = NULL;
        size_t secret_len;
+       char *temp_material = NULL;
+       size_t temp_material_len;
        char *key_material = NULL;
+       size_t key_material_len;
+       char *iv_material = NULL;
+       size_t iv_material_len;
 
-       yaca_key_h private_key = YACA_KEY_NULL;
        yaca_key_h public_key = YACA_KEY_NULL;
        yaca_key_h peer_key = YACA_KEY_NULL;
        yaca_key_h aes_key = YACA_KEY_NULL;
-
-       printf("\n***** Diffie Hellman key exchange with standard DH parameters *****");
-
-       /* generate private, public key */
-       ret = yaca_key_generate(YACA_KEY_TYPE_DH_PRIV, YACA_KEY_LENGTH_DH_RFC_2048_256, &private_key);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       yaca_key_h iv = YACA_KEY_NULL;
 
        ret = yaca_key_extract_public(private_key, &public_key);
        if (ret != YACA_ERROR_NONE)
@@ -116,158 +132,90 @@ void key_exchange_dh_standard_parameters(void)
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
+       key_material_len = YACA_KEY_LENGTH_192BIT / 8;
+       iv_material_len = YACA_KEY_LENGTH_IV_128BIT / 8;
+       temp_material_len = key_material_len + iv_material_len;
        ret = yaca_key_derive_kdf(YACA_KDF_X962, YACA_DIGEST_SHA512, secret, secret_len,
-                                 NULL, 0, YACA_KEY_LENGTH_192BIT, &key_material);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
-
-       ret = yaca_key_import(YACA_KEY_TYPE_SYMMETRIC, NULL, key_material, YACA_KEY_LENGTH_192BIT,
-                             &aes_key);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
-
-       dump_hex(secret, secret_len, "\n***** My Secret: *****");
-       dump_hex(key_material, YACA_KEY_LENGTH_192BIT, "\n***** My AES key: *****");
-
-exit:
-       yaca_key_destroy(private_key);
-       yaca_key_destroy(public_key);
-       yaca_key_destroy(peer_key);
-       yaca_key_destroy(aes_key);
-       yaca_free(secret);
-       yaca_free(key_material);
-}
-
-void key_exchange_dh_generated_parameters(void)
-{
-       int ret;
-       char *secret = NULL;
-       size_t secret_len;
-       char *key_material = NULL;
-
-       yaca_key_h params = YACA_KEY_NULL;
-       yaca_key_h private_key = YACA_KEY_NULL;
-       yaca_key_h public_key = YACA_KEY_NULL;
-       yaca_key_h peer_key = YACA_KEY_NULL;
-       yaca_key_h aes_key = YACA_KEY_NULL;
-
-       printf("\n***** Diffie Hellman key exchange with parameters generation *****");
+                                 NULL, 0, temp_material_len, &temp_material);
 
-       /* generate parameters */
-       ret = yaca_key_generate(YACA_KEY_TYPE_DH_PARAMS,
-                               YACA_KEY_LENGTH_DH_GENERATOR_2 | 1024, &params);
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
-       /* generate private, public key */
-       ret = yaca_key_generate_from_parameters(params, &private_key);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       key_material = temp_material;
+       iv_material = temp_material + key_material_len;
 
-       ret = yaca_key_extract_public(private_key, &public_key);
+       ret = yaca_key_import(YACA_KEY_TYPE_SYMMETRIC, NULL, key_material, key_material_len, &aes_key);
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
-       /* get peer public key */
-       peer_key = exchange_keys(public_key);
-       if (peer_key == YACA_KEY_NULL)
-               goto exit;
-
-       /* derive secret */
-       ret = yaca_key_derive_dh(private_key, peer_key, &secret, &secret_len);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
-
-       ret = yaca_key_derive_kdf(YACA_KDF_X962, YACA_DIGEST_SHA512, secret, secret_len,
-                                 NULL, 0, YACA_KEY_LENGTH_192BIT, &key_material);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
-
-       ret = yaca_key_import(YACA_KEY_TYPE_SYMMETRIC, NULL, key_material, YACA_KEY_LENGTH_192BIT,
-                             &aes_key);
+       ret = yaca_key_import(YACA_KEY_TYPE_IV, NULL, iv_material, iv_material_len, &iv);
        if (ret != YACA_ERROR_NONE)
                goto exit;
 
        dump_hex(secret, secret_len, "\n***** My Secret: *****");
-       dump_hex(key_material, YACA_KEY_LENGTH_192BIT, "\n***** My AES key: *****");
+       dump_hex(key_material, key_material_len, "\n***** My AES key: *****");
+       dump_hex(iv_material, iv_material_len, "\n***** My IV: *****");
 
 exit:
-       yaca_key_destroy(params);
-       yaca_key_destroy(private_key);
        yaca_key_destroy(public_key);
        yaca_key_destroy(peer_key);
        yaca_key_destroy(aes_key);
+       yaca_key_destroy(iv);
        yaca_free(secret);
-       yaca_free(key_material);
+       yaca_free(temp_material);
 }
 
-void key_exchange_ecdh(void)
+int main()
 {
-       int ret;
-       char *secret = NULL;
-       size_t secret_len;
-       char *key_material = NULL;
-
-       yaca_key_h private_key = YACA_KEY_NULL;
-       yaca_key_h public_key = YACA_KEY_NULL;
-       yaca_key_h peer_key = YACA_KEY_NULL;
-       yaca_key_h aes_key = YACA_KEY_NULL;
-
-       printf("\n***** Elliptic Curve Diffie Hellman key exchange *****");
-
-       /* generate  private, public key */
-       ret = yaca_key_generate(YACA_KEY_TYPE_EC_PRIV, YACA_KEY_LENGTH_EC_PRIME256V1, &private_key);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
-
-       ret = yaca_key_extract_public(private_key, &public_key);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       yaca_debug_set_error_cb(debug_func);
 
-       /* get peer public key */
-       peer_key = exchange_keys(public_key);
-       if (peer_key == YACA_KEY_NULL)
-               goto exit;
+       yaca_key_h ecdh_key = YACA_KEY_NULL;
+       yaca_key_h dh_params = YACA_KEY_NULL;
+       yaca_key_h dh_key_from_params = YACA_KEY_NULL;
+       yaca_key_h dh_key = YACA_KEY_NULL;
 
-       /* derive secret */
-       ret = yaca_key_derive_dh(private_key, peer_key, &secret, &secret_len);
+       int ret = yaca_initialize();
        if (ret != YACA_ERROR_NONE)
-               goto exit;
+               return ret;
 
-       ret = yaca_key_derive_kdf(YACA_KDF_X962, YACA_DIGEST_SHA512, secret, secret_len,
-                                 NULL, 0, YACA_KEY_LENGTH_192BIT, &key_material);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+       printf("\n***** Elliptic Curve Diffie Hellman key exchange and key/iv derivation *****");
+       {
+               ret = yaca_key_generate(YACA_KEY_TYPE_EC_PRIV, YACA_KEY_LENGTH_EC_PRIME256V1, &ecdh_key);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
 
-       ret = yaca_key_import(YACA_KEY_TYPE_SYMMETRIC, NULL, key_material, YACA_KEY_LENGTH_192BIT,
-                             &aes_key);
-       if (ret != YACA_ERROR_NONE)
-               goto exit;
+               key_derivation(ecdh_key);
+       }
 
-       dump_hex(secret, secret_len, "\n***** My Secret: *****");
-       dump_hex(key_material, YACA_KEY_LENGTH_192BIT, "\n***** My AES key: *****");
+       printf("\n***** Diffie Hellman Diffie Hellman key exchange and key/iv derivation *****");
+       {
+               ret = yaca_key_generate(YACA_KEY_TYPE_DH_PARAMS,
+                                       YACA_KEY_LENGTH_DH_GENERATOR_2 | 1024, &dh_params);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
 
-exit:
-       yaca_key_destroy(private_key);
-       yaca_key_destroy(public_key);
-       yaca_key_destroy(peer_key);
-       yaca_key_destroy(aes_key);
-       yaca_free(secret);
-       yaca_free(key_material);
-}
+               ret = yaca_key_generate_from_parameters(dh_params, &dh_key_from_params);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
 
-int main()
-{
-       yaca_debug_set_error_cb(debug_func);
+               key_derivation(dh_key_from_params);
+       }
 
-       int ret = yaca_initialize();
-       if (ret != YACA_ERROR_NONE)
-               return ret;
+       printf("\n***** Diffie Hellman Diffie Hellman key exchange and key/iv derivation *****");
+       {
+               ret = yaca_key_generate(YACA_KEY_TYPE_DH_PRIV, YACA_KEY_LENGTH_DH_RFC_2048_256, &dh_key);
+               if (ret != YACA_ERROR_NONE)
+                       goto exit;
 
-       key_exchange_dh_standard_parameters();
-       key_exchange_dh_generated_parameters();
-       key_exchange_ecdh();
+               key_derivation(dh_key);
+       }
 
+exit:
+       yaca_key_destroy(ecdh_key);
+       yaca_key_destroy(dh_params);
+       yaca_key_destroy(dh_key_from_params);
+       yaca_key_destroy(dh_key);
        yaca_cleanup();
+
        return ret;
 }

diff --git a/src/key.c b/src/key.c
index a79010c..92bc8a3 100644 (file)
--- a/src/key.c
+++ b/src/key.c
@@ -1827,7 +1827,7 @@ API int yaca_key_derive_kdf(yaca_kdf_e kdf,
                             size_t secret_len,
                             const char *info,
                             size_t info_len,
-                            size_t key_material_bit_len,
+                            size_t key_material_len,
                             char **key_material)
 {
        int ret;
@@ -1836,10 +1836,10 @@ API int yaca_key_derive_kdf(yaca_kdf_e kdf,
 
        if (secret == NULL || secret_len == 0 ||
            (info == NULL && info_len > 0) || (info != NULL && info_len == 0) ||
-           key_material_bit_len == 0 || key_material == NULL)
+           key_material_len == 0 || key_material == NULL)
                return YACA_ERROR_INVALID_PARAMETER;
 
-       ret = yaca_zalloc(key_material_bit_len, (void**)&out);
+       ret = yaca_zalloc(key_material_len, (void**)&out);
        if (ret != YACA_ERROR_NONE)
                return ret;
 
@@ -1849,7 +1849,7 @@ API int yaca_key_derive_kdf(yaca_kdf_e kdf,
 
        switch (kdf) {
        case YACA_KDF_X942:
-               ret = DH_KDF_X9_42((unsigned char*)out, key_material_bit_len,
+               ret = DH_KDF_X9_42((unsigned char*)out, key_material_len,
                                   (unsigned char*)secret, secret_len,
                                   OBJ_nid2obj(NID_id_smime_alg_ESDH), (unsigned char*)info, info_len, md);
                if (ret != 1 || out == NULL) {
@@ -1859,7 +1859,7 @@ API int yaca_key_derive_kdf(yaca_kdf_e kdf,
                }
                break;
        case YACA_KDF_X962:
-               ret = ECDH_KDF_X9_62((unsigned char*)out, key_material_bit_len,
+               ret = ECDH_KDF_X9_62((unsigned char*)out, key_material_len,
                                     (unsigned char*)secret, secret_len,
                                     (unsigned char*)info, info_len, md);
                if (ret != 1 || out == NULL) {