diff options
Diffstat (limited to 'include/axolotl/crypto.hh')
| -rw-r--r-- | include/axolotl/crypto.hh | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/include/axolotl/crypto.hh b/include/axolotl/crypto.hh index d3586b3..09e5b8e 100644 --- a/include/axolotl/crypto.hh +++ b/include/axolotl/crypto.hh @@ -28,7 +28,7 @@ struct Curve25519KeyPair : public Curve25519PublicKey { std::uint8_t private_key[32]; }; - +/** Generate a curve25519 key pair from 32 random bytes. */ void generate_key( std::uint8_t const * random_32_bytes, Curve25519KeyPair & key_pair @@ -37,7 +37,8 @@ void generate_key( const std::size_t CURVE25519_SHARED_SECRET_LENGTH = 32; - +/** 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, @@ -57,11 +58,14 @@ struct Aes256Iv { }; +/** The length of output the aes_encrypt_cbc function will write */ std::size_t aes_encrypt_cbc_length( std::size_t input_length ); +/** Encrypts the input using AES256 in CBC mode with PKCS#7 padding. + * The output buffer must be big enough to hold the output including padding */ void aes_encrypt_cbc( Aes256Key const & key, Aes256Iv const & iv, @@ -70,6 +74,10 @@ void aes_encrypt_cbc( ); +/** Decrypts the input using AES256 in CBC mode. The output buffer must be at + * least the same size as the input buffer. Returns the length of the plaintext + * without padding on success or std::size_t(-1) if the padding is invalid. + */ std::size_t aes_decrypt_cbc( Aes256Key const & key, Aes256Iv const & iv, @@ -78,6 +86,8 @@ std::size_t aes_decrypt_cbc( ); +/** Computes SHA-256 of the input. The output buffer must be a least 32 + * bytes long. */ void sha256( std::uint8_t const * input, std::size_t input_length, std::uint8_t * output @@ -87,6 +97,10 @@ void sha256( const std::size_t HMAC_SHA256_OUTPUT_LENGTH = 32; +/** 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. */ void hmac_sha256( std::uint8_t const * key, std::size_t key_length, std::uint8_t const * input, std::size_t input_length, @@ -94,6 +108,9 @@ void hmac_sha256( ); +/** HMAC-based Key Derivation Function (HKDF) + * https://tools.ietf.org/html/rfc5869 + * Derives key material from the input bytes. */ void hkdf_sha256( std::uint8_t const * input, std::size_t input_length, std::uint8_t const * info, std::size_t info_length, |