diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/crypto.cpp | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/src/crypto.cpp b/src/crypto.cpp index 5277b86..e93a1e9 100644 --- a/src/crypto.cpp +++ b/src/crypto.cpp @@ -107,26 +107,13 @@ void axolotl::curve25519_shared_secret( } -std::size_t axolotl::aes_pkcs_7_padded_length( +std::size_t axolotl::aes_encrypt_cbc_length( std::size_t input_length ) { return input_length + AES_BLOCK_LENGTH - input_length % AES_BLOCK_LENGTH; } -void axolotl::aes_pkcs_7_padding( - std::uint8_t const * input, std::size_t input_length, - std::uint8_t * output -) { - std::memcpy(output, input, input_length); - std::size_t padded_length = axolotl::aes_pkcs_7_padded_length(input_length); - std::uint8_t padding = padded_length - input_length; - for (std::size_t i = input_length; i < padded_length; ++i) { - output[i] = padding; - } -} - - void axolotl::aes_encrypt_cbc( axolotl::Aes256Key const & key, axolotl::Aes256Iv const & iv, @@ -137,17 +124,28 @@ void axolotl::aes_encrypt_cbc( ::aes_key_setup(key.key, key_schedule, 256); std::uint8_t input_block[AES_BLOCK_LENGTH]; std::memcpy(input_block, iv.iv, AES_BLOCK_LENGTH); - for (std::size_t i = 0; i < input_length; i += AES_BLOCK_LENGTH) { - xor_block<AES_BLOCK_LENGTH>(input_block, &input[i]); - ::aes_encrypt(input_block, &output[i], key_schedule, 256); - std::memcpy(input_block, &output[i], AES_BLOCK_LENGTH); + while (input_length >= AES_BLOCK_LENGTH) { + xor_block<AES_BLOCK_LENGTH>(input_block, input); + ::aes_encrypt(input_block, output, key_schedule, 256); + std::memcpy(input_block, output, AES_BLOCK_LENGTH); + input += AES_BLOCK_LENGTH; + output += AES_BLOCK_LENGTH; + input_length -= AES_BLOCK_LENGTH; + } + std::size_t i = 0; + for (; i < input_length; ++i) { + input_block[i] ^= input[i]; + } + for (; i < AES_BLOCK_LENGTH; ++i) { + input_block[i] ^= AES_BLOCK_LENGTH - input_length; } + ::aes_encrypt(input_block, output, key_schedule, 256); std::memset(key_schedule, 0, sizeof(key_schedule)); std::memset(input_block, 0, sizeof(AES_BLOCK_LENGTH)); } -void axolotl::aes_decrypt_cbc( +std::size_t axolotl::aes_decrypt_cbc( axolotl::Aes256Key const & key, axolotl::Aes256Iv const & iv, std::uint8_t const * input, std::size_t input_length, @@ -164,6 +162,8 @@ void axolotl::aes_decrypt_cbc( } } std::memset(key_schedule, 0, sizeof(key_schedule)); + std::size_t padding = output[input_length - 1]; + return (padding > input_length) ? std::size_t(-1) : (input_length - padding); } |