Interface: BlockCipher

Author: Naveen Sastry

Components providing this interface:: tos.lib.TinySec.SkipJackM

Components requiring this interface:: tos.lib.TinySec.CBCMAC
tos.lib.TinySec.CBCModeM

Commands

result_t init (CipherContext *context, uint8_t blockSize, uint8_t keySize, uint8_t *key) Initialize the BlockCipher context.
result_t encrypt (CipherContext *context, uint8_t *plainBlock, uint8_t *cipherBlock) Encrypts a single block (of blockSize) using the key in the keySize.
result_t decrypt (CipherContext *context, uint8_t *cipherBlock, uint8_t *plainBlock) Decrypts a single block (of blockSize) using the key in the keySize.

Commands - Details

init

result_t init(CipherContext *context, uint8_t blockSize, uint8_t keySize, uint8_t *key)

Initialize the BlockCipher context.

Parameters:	context - structure to hold the opaque data from this initialization call. It should be passed to future invocations of this module which use this particular key. blockSize - size of the block in bytes. Some cipher implementation may support multiple block sizes, in which case any valid size is valid. keySize - key size in bytes key - pointer to the key
Returns:	Whether initialization was successful. The command may be unsuccessful if the key size or blockSize are not valid for the given cipher implementation.

encrypt

result_t encrypt(CipherContext *context, uint8_t *plainBlock, uint8_t *cipherBlock)

Encrypts a single block (of blockSize) using the key in the keySize.

Parameters:	context - holds the module specific opaque data related to the key (perhaps key expansions). plainBlock - a plaintext block of blockSize cipherBlock - the resulting ciphertext block of blockSize
Returns:	Whether the encryption was successful. Possible failure reasons include not calling init().

decrypt

result_t decrypt(CipherContext *context, uint8_t *cipherBlock, uint8_t *plainBlock)

Decrypts a single block (of blockSize) using the key in the keySize. Not all ciphers will implement this function (since providing encryption is a useful primitive).

Parameters:	context - holds the module specific opaque data related to the key (perhaps key expansions). cipherBlock - a ciphertext block of blockSize plainBlock - the resulting plaintext block of blockSize
Returns:	Whether the decryption was successful. Possible failure reasons include not calling init() or an unimplimented decrypt function.