diff options
Diffstat (limited to 'aes.c')
| -rw-r--r-- | aes.c | 30 |
1 files changed, 15 insertions, 15 deletions
@@ -42,6 +42,7 @@ NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0) /*****************************************************************************/ // The number of columns comprising a state in AES. This is a constant in AES. Value=4 #define Nb 4 +#define BLOCKLEN 16 //Block length in bytes AES is 128b block only #ifdef AES256 #define Nk 8 @@ -177,7 +178,7 @@ static void KeyExpansion(void) // All other round keys are found from the previous round keys. //i == Nk - for(i = Nk; i < Nb * (Nr + 1); ++i) + for(; i < Nb * (Nr + 1); ++i) { { tempa[0]=RoundKey[(i-1) * 4 + 0]; @@ -494,7 +495,7 @@ void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, static void XorWithIv(uint8_t* buf) { uint8_t i; - for(i = 0; i < 16; ++i) //WAS for(i = 0; i < KEYLEN; ++i) but the block in AES is always 128bit so 16 bytes! + for(i = 0; i < BLOCKLEN; ++i) //WAS for(i = 0; i < KEYLEN; ++i) but the block in AES is always 128bit so 16 bytes! { buf[i] ^= Iv[i]; } @@ -503,9 +504,9 @@ static void XorWithIv(uint8_t* buf) void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv) { uintptr_t i; - uint8_t extra = length % 16; /* Remaining bytes in the last non-full block */ + uint8_t extra = length % BLOCKLEN; /* Remaining bytes in the last non-full block */ - memcpy(output, input, 16); + memcpy(output, input, BLOCKLEN); state = (state_t*)output; // Skip the key expansion if key is passed as 0 @@ -520,21 +521,20 @@ void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, co Iv = (uint8_t*)iv; } - for(i = 0; i < length; i += 16) + for(i = 0; i < length; i += BLOCKLEN) { XorWithIv(input); - memcpy(output, input, 16); + memcpy(output, input, BLOCKLEN); state = (state_t*)output; Cipher(); Iv = output; - input += 16; - output += 16; + input += BLOCKLEN; + output += BLOCKLEN; //printf("Step %d - %d", i/16, i); } if(extra) { - printf("NONO\n"); memcpy(output, input, extra); state = (state_t*)output; Cipher(); @@ -544,9 +544,9 @@ void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, co void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv) { uintptr_t i; - uint8_t extra = length % 16; /* Remaining bytes in the last non-full block */ + uint8_t extra = length % BLOCKLEN; /* Remaining bytes in the last non-full block */ - memcpy(output, input, 16); + memcpy(output, input, BLOCKLEN); state = (state_t*)output; // Skip the key expansion if key is passed as 0 @@ -562,15 +562,15 @@ void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, co Iv = (uint8_t*)iv; } - for(i = 0; i < length; i += 16) + for(i = 0; i < length; i += BLOCKLEN) { - memcpy(output, input, 16); + memcpy(output, input, BLOCKLEN); state = (state_t*)output; InvCipher(); XorWithIv(output); Iv = input; - input += 16; - output += 16; + input += BLOCKLEN; + output += BLOCKLEN; } if(extra) |