diff options
| -rw-r--r-- | src/buffer.c | 36 |
1 files changed, 30 insertions, 6 deletions
diff --git a/src/buffer.c b/src/buffer.c index d8ff9c7..ff14f18 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -11,6 +11,8 @@ #include <stdlib.h> #include <string.h> +static unsigned char FULL_BLOCK_PADDING[16] = { 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16 }; + size_t aes128ecb_encrypt_buffer( const unsigned char* src, size_t src_size, @@ -33,9 +35,13 @@ size_t aes128ecb_encrypt_buffer( store_aes_block128(ciphertext, dest); } - unsigned char padding[16] = { 0x10 }; + unsigned char padding[16]; - if (rem_size != 0) + if (rem_size == 0) + { + memcpy(padding, FULL_BLOCK_PADDING, 16); + } + else { memcpy(padding, src, rem_size); memset(padding + rem_size, padding_size, padding_size); @@ -48,6 +54,18 @@ size_t aes128ecb_encrypt_buffer( return dest_size; } +static unsigned char get_padding_size(const unsigned char* padding) +{ + if (padding[15] < 0x01 || padding[15] > 0x10) + return 0; + + for (int i = 16 - padding[15]; i < 15; ++i) + if (padding[i] != padding[15]) + return 0; + + return padding[15]; +} + size_t aes128ecb_decrypt_buffer( const unsigned char* src, size_t src_size, @@ -73,9 +91,15 @@ size_t aes128ecb_decrypt_buffer( unsigned char padding[16]; store_aes_block128(plaintext, padding); - if (padding[0] == 0x10) - return dest_size - 16; + unsigned char padding_size = get_padding_size(padding); - memcpy(dest, padding, 16 - padding[15]); - return dest_size - padding[15]; + if (padding_size == 0) + { + return dest_size - 16; + } + else + { + memcpy(dest, padding, 16 - padding_size); + return dest_size - padding_size; + } } |