aes.h

Headers for the implementation of the AES cipher-algorithm.

GETU32( pt)
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2
(((u32)(pt)[0] << 24) ^ ((u32)(pt)[1] << 16) ^ \
                     ((u32)(pt)[2] <<  8) ^ ((u32)(pt)[3]))
PUTU32( ct, st)
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2
3
4
{ (ct)[0] = (u8)((st) >> 24); \
                          (ct)[1] = (u8)((st) >> 16); \
                          (ct)[2] = (u8)((st) >>  8); \
                          (ct)[3] = (u8)(st); }
AES_MAXNR
1
14
AES_BLOCK_SIZE
1
16
AES_KEY_SIZE
1
16
uint32_t u32
uint16_t u16
uint8_t u8
struct aes_key_st AES_KEY
int aes_init(cipher_context_t * context, const uint8_t * key, uint8_t keySize)

initializes the AES Cipher-algorithm with the passed parameters

Parameters

context:the cipher_context_t-struct to save the initialization of the cipher in
keySize:the size of the key
key:a pointer to the key

Return values

  • CIPHER_INIT_SUCCESS if the initialization was successful.
  • CIPHER_ERR_BAD_CONTEXT_SIZE if CIPHER_MAX_CONTEXT_SIZE has not been defined (which means that the cipher has not been included in the build)
int aes_encrypt(const cipher_context_t * context, const uint8_t * plain_block, uint8_t * cipher_block)

encrypts one plainBlock-block and saves the result in cipherblock.

encrypts one blocksize long block of plaintext pointed to by plainBlock to one blocksize long block of ciphertext which will be written to the the memory-area pointed to by cipherBlock

Parameters

context:the cipher_context_t-struct to use for this encryption
plain_block:a pointer to the plaintext-block (of size blocksize)
cipher_block:a pointer to the place where the ciphertext will be stored

Return values

  • 1 on success
  • A negative value if the cipher key cannot be expanded with the AES key schedule
int aes_decrypt(const cipher_context_t * context, const uint8_t * cipher_block, uint8_t * plain_block)

decrypts one cipher-block and saves the plain-block in plainBlock.

decrypts one blocksize long block of ciphertext pointed to by cipherBlock to one blocksize long block of plaintext and stores the plaintext in the memory-area pointed to by plainBlock

Parameters

context:the cipher_context_t-struct to use for this decryption
cipher_block:a pointer to the ciphertext-block (of size blocksize) to be decrypted
plain_block:a pointer to the place where the decrypted plaintext will be stored

Return values

  • 1 on success
  • A negative value if the cipher key cannot be expanded with the AES key schedule
struct aes_key_st

AES key.

See also

cipher_context_t

struct aes_context_t

the cipher_context_t-struct adapted for AES

uint32_t context()

context data buffer