diff options
Diffstat (limited to 'aes.h')
| -rw-r--r-- | aes.h | 52 |
1 files changed, 44 insertions, 8 deletions
@@ -28,26 +28,62 @@ //#define AES192 1 //#define AES256 1 -#if defined(ECB) && (ECB == 1) +#define AES_BLOCKLEN 16 //Block length in bytes AES is 128b block only + +#if defined(AES256) && (AES256 == 1) + #define AES_KEYLEN 32 + #define AES_keyExpSize 240 +#elif defined(AES192) && (AES192 == 1) + #define AES_KEYLEN 24 + #define AES_keyExpSize 208 +#else + #define AES_KEYLEN 16 // Key length in bytes + #define AES_keyExpSize 176 +#endif + +struct AES_ctx { + uint8_t RoundKey[AES_keyExpSize]; + #if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) + uint8_t Iv[AES_BLOCKLEN]; + #endif +}; + +void AES_init_ctx(struct AES_ctx *ctx,const uint8_t* key); +#if defined(CBC) && (CBC == 1) +void AES_init_ctx_iv(struct AES_ctx *ctx,const uint8_t* key,const uint8_t* iv); +void AES_ctx_set_iv(struct AES_ctx *ctx,const uint8_t* iv); +#endif -void AES_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length); -void AES_ECB_decrypt(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length); +#if defined(ECB) && (ECB == 1) +// buffer size is exactly AES_BLOCKLEN bytes; +// you need only AES_init_ctx as Iv is not used in ECB +// NB: ECB s considered insecure +void AES_ECB_encrypt(struct AES_ctx *ctx, const uint8_t* input, uint8_t *output); +void AES_ECB_decrypt(struct AES_ctx *ctx, const uint8_t* input, uint8_t *output); #endif // #if defined(ECB) && (ECB == !) #if defined(CBC) && (CBC == 1) - -void AES_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv); -void AES_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv); +// buffer size MUST be mutile of AES_BLOCKLEN; +// We suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 if you need one +// you need to set iv in ctx via AES_init_ctx_iv or AES_ctx_set_iv +// NB: no IV should ever be reused with the same key +void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input, uint32_t length); +void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input, uint32_t length); #endif // #if defined(CBC) && (CBC == 1) #if defined(CTR) && (CTR == 1) -/* Same function for encrypting as for decrypting. Note no IV/nonce should ever be reused with the same key */ -void AES_CTR_xcrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* nonce); +// Same function for encrypting as for decrypting. +// iv is incremented for every block, and usesd after encryption as xor compliment for output +// buffer size MUST be mutile of AES_BLOCKLEN; +// We suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 if you need one +// you need to set iv in ctx via AES_init_ctx_iv or AES_ctx_set_iv +// NB: no IV should ever be reused with the same key +void AES_CTR_xcrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input, uint32_t length); #endif // #if defined(CTR) && (CTR == 1) |