Convert Ed25519 and Curve25519 functions to plain C

7 files changed, 108 insertions, 96 deletions

diff --git a/include/olm/account.hh b/include/olm/account.hh
index 6ea0d19..4b7b190 100644
--- a/include/olm/account.hh
+++ b/include/olm/account.hh
@@ -25,14 +25,14 @@ namespace olm {
 
 
 struct IdentityKeys {
-    Ed25519KeyPair ed25519_key;
-    Curve25519KeyPair curve25519_key;
+    _olm_ed25519_key_pair ed25519_key;
+    _olm_curve25519_key_pair curve25519_key;
 };
 
 struct OneTimeKey {
     std::uint32_t id;
     bool published;
-    Curve25519KeyPair key;
+    _olm_curve25519_key_pair key;
 };
 
 
@@ -128,12 +128,12 @@ struct Account {
 
     /** Lookup a one time key with the given public key */
     OneTimeKey const * lookup_key(
-        Curve25519PublicKey const & public_key
+        _olm_curve25519_public_key const & public_key
     );
 
     /** Remove a one time key with the given public key */
     std::size_t remove_key(
-        Curve25519PublicKey const & public_key
+        _olm_curve25519_public_key const & public_key
     );
 };
 
diff --git a/include/olm/crypto.h b/include/olm/crypto.h
index 325080e..9fc3842 100644
--- a/include/olm/crypto.h
+++ b/include/olm/crypto.h
@@ -57,9 +57,35 @@ extern "C" {
 /** length of an aes256 initialisation vector */
 #define AES256_IV_LENGTH 16
 
+struct _olm_curve25519_public_key {
+    uint8_t public_key[CURVE25519_KEY_LENGTH];
+};
 
-/** Computes SHA-256 of the input. The output buffer must be a least 32
- * bytes long. */
+struct _olm_curve25519_private_key {
+    uint8_t private_key[CURVE25519_KEY_LENGTH];
+};
+
+struct _olm_curve25519_key_pair {
+    struct _olm_curve25519_public_key public_key;
+    struct _olm_curve25519_private_key private_key;
+};
+
+struct _olm_ed25519_public_key {
+    uint8_t public_key[ED25519_PUBLIC_KEY_LENGTH];
+};
+
+struct _olm_ed25519_private_key {
+    uint8_t private_key[ED25519_PRIVATE_KEY_LENGTH];
+};
+
+struct _olm_ed25519_key_pair {
+    struct _olm_ed25519_public_key public_key;
+    struct _olm_ed25519_private_key private_key;
+};
+
+
+/** Computes SHA-256 of the input. The output buffer must be a least
+ * SHA256_OUTPUT_LENGTH (32) bytes long. */
 void _olm_crypto_sha256(
     uint8_t const * input, size_t input_length,
     uint8_t * output
@@ -68,7 +94,7 @@ void _olm_crypto_sha256(
 /** HMAC: Keyed-Hashing for Message Authentication
  * http://tools.ietf.org/html/rfc2104
  * Computes HMAC-SHA-256 of the input for the key. The output buffer must
- * be at least 32 bytes long. */
+ * be at least SHA256_OUTPUT_LENGTH (32) bytes long. */
 void _olm_crypto_hmac_sha256(
     uint8_t const * key, size_t key_length,
     uint8_t const * input, size_t input_length,
@@ -87,6 +113,53 @@ void _olm_crypto_hkdf_sha256(
 );
 
 
+/** Generate a curve25519 key pair
+ * random_32_bytes should be CURVE25519_RANDOM_LENGTH (32) bytes long.
+ */
+void _olm_crypto_curve25519_generate_key(
+    uint8_t const * random_32_bytes,
+    struct _olm_curve25519_key_pair *output
+);
+
+
+/** Create a shared secret using our private key and their public key.
+ * The output buffer must be at least CURVE25519_SHARED_SECRET_LENGTH (32) bytes long.
+ */
+void _olm_crypto_curve25519_shared_secret(
+    const struct _olm_curve25519_key_pair *our_key,
+    const struct _olm_curve25519_public_key *their_key,
+    uint8_t * output
+);
+
+/** Generate an ed25519 key pair
+ * random_32_bytes should be ED25519_RANDOM_LENGTH (32) bytes long.
+ */
+void _olm_crypto_ed25519_generate_key(
+    uint8_t const * random_bytes,
+    struct _olm_ed25519_key_pair *output
+);
+
+/** Signs the message using our private key.
+ *
+ * The output buffer must be at least ED25519_SIGNATURE_LENGTH (64) bytes
+ * long. */
+void _olm_crypto_ed25519_sign(
+    const struct _olm_ed25519_key_pair *our_key,
+    const uint8_t * message, size_t message_length,
+    uint8_t * output
+);
+
+/** Verify an ed25519 signature
+ * The signature input buffer must be ED25519_SIGNATURE_LENGTH (64) bytes long.
+ * Returns non-zero if the signature is valid. */
+int _olm_crypto_ed25519_verify(
+    const struct _olm_ed25519_public_key *their_key,
+    const uint8_t * message, size_t message_length,
+    const uint8_t * signature
+);
+
+
+
 #ifdef __cplusplus
 } // extern "C"
 #endif
diff --git a/include/olm/crypto.hh b/include/olm/crypto.hh
index 13fd7e9..e3098cc 100644
--- a/include/olm/crypto.hh
+++ b/include/olm/crypto.hh
@@ -25,67 +25,6 @@
 
 namespace olm {
 
-struct Curve25519PublicKey {
-    std::uint8_t public_key[CURVE25519_KEY_LENGTH];
-};
-
-
-struct Curve25519KeyPair : public Curve25519PublicKey {
-    std::uint8_t private_key[CURVE25519_KEY_LENGTH];
-};
-
-
-struct Ed25519PublicKey {
-    std::uint8_t public_key[ED25519_PUBLIC_KEY_LENGTH];
-};
-
-
-struct Ed25519KeyPair : public Ed25519PublicKey {
-    std::uint8_t private_key[ED25519_PRIVATE_KEY_LENGTH];
-};
-
-
-/** Generate a curve25519 key pair from 32 random bytes. */
-void curve25519_generate_key(
-    std::uint8_t const * random_32_bytes,
-    Curve25519KeyPair & key_pair
-);
-
-
-/** Create a shared secret using our private key and their public key.
- * The output buffer must be at least 32 bytes long. */
-void curve25519_shared_secret(
-    Curve25519KeyPair const & our_key,
-    Curve25519PublicKey const & their_key,
-    std::uint8_t * output
-);
-
-
-/** Generate a curve25519 key pair from 32 random bytes. */
-void ed25519_generate_key(
-    std::uint8_t const * random_32_bytes,
-    Ed25519KeyPair & key_pair
-);
-
-
-/** Signs the message using our private key.
- * The output buffer must be at least 64 bytes long. */
-void ed25519_sign(
-    Ed25519KeyPair const & our_key,
-    std::uint8_t const * message, std::size_t message_length,
-    std::uint8_t * output
-);
-
-
-/** Verify their message using their public key.
- * The signature input buffer must be 64 bytes long.
- * Returns true if the signature is valid. */
-bool ed25519_verify(
-    Ed25519PublicKey const & their_key,
-    std::uint8_t const * message, std::size_t message_length,
-    std::uint8_t const * signature
-);
-
 
 struct Aes256Key {
     std::uint8_t key[AES256_KEY_LENGTH];
diff --git a/include/olm/pickle.hh b/include/olm/pickle.hh
index 13e6b01..c0b6ebf 100644
--- a/include/olm/pickle.hh
+++ b/include/olm/pickle.hh
@@ -109,70 +109,70 @@ std::uint8_t const * unpickle_bytes(
 
 
 std::size_t pickle_length(
-    const Curve25519PublicKey & value
+    const _olm_curve25519_public_key & value
 );
 
 
 std::uint8_t * pickle(
     std::uint8_t * pos,
-    const Curve25519PublicKey & value
+    const _olm_curve25519_public_key & value
 );
 
 
 std::uint8_t const * unpickle(
     std::uint8_t const * pos, std::uint8_t const * end,
-    Curve25519PublicKey & value
+    _olm_curve25519_public_key & value
 );
 
 
 std::size_t pickle_length(
-    const Curve25519KeyPair & value
+    const _olm_curve25519_key_pair & value
 );
 
 
 std::uint8_t * pickle(
     std::uint8_t * pos,
-    const Curve25519KeyPair & value
+    const _olm_curve25519_key_pair & value
 );
 
 
 std::uint8_t const * unpickle(
     std::uint8_t const * pos, std::uint8_t const * end,
-    Curve25519KeyPair & value
+    _olm_curve25519_key_pair & value
 );
 
 
 std::size_t pickle_length(
-    const Ed25519PublicKey & value
+    const _olm_ed25519_public_key & value
 );
 
 
 std::uint8_t * pickle(
     std::uint8_t * pos,
-    const Ed25519PublicKey & value
+    const _olm_ed25519_public_key & value
 );
 
 
 std::uint8_t const * unpickle(
     std::uint8_t const * pos, std::uint8_t const * end,
-    Ed25519PublicKey & value
+    _olm_ed25519_public_key & value
 );
 
 
 std::size_t pickle_length(
-    const Ed25519KeyPair & value
+    const _olm_ed25519_key_pair & value
 );
 
 
 std::uint8_t * pickle(
     std::uint8_t * pos,
-    const Ed25519KeyPair & value
+    const _olm_ed25519_key_pair & value
 );
 
 
 std::uint8_t const * unpickle(
     std::uint8_t const * pos, std::uint8_t const * end,
-    Ed25519KeyPair & value
+    _olm_ed25519_key_pair & value
 );
 
 } // namespace olm
diff --git a/include/olm/ratchet.hh b/include/olm/ratchet.hh
index e91d634..cdcba6b 100644
--- a/include/olm/ratchet.hh
+++ b/include/olm/ratchet.hh
@@ -41,19 +41,19 @@ struct MessageKey {
 
 
 struct SenderChain {
-    Curve25519KeyPair ratchet_key;
+    _olm_curve25519_key_pair ratchet_key;
     ChainKey chain_key;
 };
 
 
 struct ReceiverChain {
-    Curve25519PublicKey ratchet_key;
+    _olm_curve25519_public_key ratchet_key;
     ChainKey chain_key;
 };
 
 
 struct SkippedMessageKey {
-    Curve25519PublicKey ratchet_key;
+    _olm_curve25519_public_key ratchet_key;
     MessageKey message_key;
 };
 
@@ -108,14 +108,14 @@ struct Ratchet {
      * remote's first ratchet key */
     void initialise_as_bob(
         std::uint8_t const * shared_secret, std::size_t shared_secret_length,
-        Curve25519PublicKey const & their_ratchet_key
+        _olm_curve25519_public_key const & their_ratchet_key
     );
 
     /** Initialise the session using a shared secret and the public/private key
      * pair for the first ratchet key */
     void initialise_as_alice(
         std::uint8_t const * shared_secret, std::size_t shared_secret_length,
-        Curve25519KeyPair const & our_ratchet_key
+        _olm_curve25519_key_pair const & our_ratchet_key
     );
 
     /** The number of bytes of output the encrypt method will write for
diff --git a/include/olm/session.hh b/include/olm/session.hh
index 5b91cb1..9d44816 100644
--- a/include/olm/session.hh
+++ b/include/olm/session.hh
@@ -35,9 +35,9 @@ struct Session {
 
     bool received_message;
 
-    Curve25519PublicKey alice_identity_key;
-    Curve25519PublicKey alice_base_key;
-    Curve25519PublicKey bob_one_time_key;
+    _olm_curve25519_public_key alice_identity_key;
+    _olm_curve25519_public_key alice_base_key;
+    _olm_curve25519_public_key bob_one_time_key;
 
     /** The number of random bytes that are needed to create a new outbound
      * session. This will be 64 bytes since two ephemeral keys are needed. */
@@ -48,8 +48,8 @@ struct Session {
      * NOT_ENOUGH_RANDOM if the number of random bytes was too small. */
     std::size_t new_outbound_session(
         Account const & local_account,
-        Curve25519PublicKey const & identity_key,
-        Curve25519PublicKey const & one_time_key,
+        _olm_curve25519_public_key const & identity_key,
+        _olm_curve25519_public_key const & one_time_key,
         std::uint8_t const * random, std::size_t random_length
     );
 
@@ -59,7 +59,7 @@ struct Session {
      * the message headers could not be decoded. */
     std::size_t new_inbound_session(
         Account & local_account,
-        Curve25519PublicKey const * their_identity_key,
+        _olm_curve25519_public_key const * their_identity_key,
         std::uint8_t const * pre_key_message, std::size_t message_length
     );
 
@@ -82,7 +82,7 @@ struct Session {
      * session does not match or the pre-key message could not be decoded.
      */
     bool matches_inbound_session(
-        Curve25519PublicKey const * their_identity_key,
+        _olm_curve25519_public_key const * their_identity_key,
         std::uint8_t const * pre_key_message, std::size_t message_length
     );
 
diff --git a/include/olm/utility.hh b/include/olm/utility.hh
index 1339fe5..d650abc 100644
--- a/include/olm/utility.hh
+++ b/include/olm/utility.hh
@@ -21,9 +21,9 @@
 #include <cstddef>
 #include <cstdint>
 
-namespace olm {
+struct _olm_ed25519_public_key;
 
-struct Ed25519PublicKey;
+namespace olm {
 
 struct Utility {
 
@@ -48,7 +48,7 @@ struct Utility {
      * last_error will be set with an error code. If the signature was too short
      * or was not a valid signature then last_error will be BAD_MESSAGE_MAC. */
     std::size_t ed25519_verify(
-        Ed25519PublicKey const & key,
+        _olm_ed25519_public_key const & key,
         std::uint8_t const * message, std::size_t message_length,
         std::uint8_t const * signature, std::size_t signature_length
     );