diff options
| -rw-r--r-- | README.md | 1 | ||||
| -rw-r--r-- | aes.c | 17 |
2 files changed, 11 insertions, 7 deletions
@@ -28,6 +28,7 @@ void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); Note: * No padding is provided so for CBC and ECB all buffers should be multiples of 16 bytes. For padding [PKCS7](https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7) is recommendable. * ECB mode is considered unsafe for most uses and is not implemented in streaming mode. If you need this mode, call the function for every block of 16 bytes you need encrypted. See [wikipedia's article on ECB](https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Electronic_Codebook_(ECB)) for more details. + * This library is not super fast. It is intended for portability and small size, not high speed. OpenSSL for example, is probably much faster. You can choose to use any or all of the modes-of-operations, by defining the symbols CBC, CTR or ECB. See the header file for clarification. @@ -95,6 +95,7 @@ static const uint8_t sbox[256] = { 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) static const uint8_t rsbox[256] = { 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, @@ -112,6 +113,7 @@ static const uint8_t rsbox[256] = { 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d }; +#endif // The round constant word array, Rcon[i], contains the values given by // x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8) @@ -139,13 +141,6 @@ static uint8_t getSBoxValue(uint8_t num) } */ #define getSBoxValue(num) (sbox[(num)]) -/* -static uint8_t getSBoxInvert(uint8_t num) -{ - return rsbox[num]; -} -*/ -#define getSBoxInvert(num) (rsbox[(num)]) // This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. static void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key) @@ -341,6 +336,14 @@ static uint8_t Multiply(uint8_t x, uint8_t y) #endif #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) +/* +static uint8_t getSBoxInvert(uint8_t num) +{ + return rsbox[num]; +} +*/ +#define getSBoxInvert(num) (rsbox[(num)]) + // MixColumns function mixes the columns of the state matrix. // The method used to multiply may be difficult to understand for the inexperienced. // Please use the references to gain more information. |