libkeccak_hmac_update3
Partially hmac-hash a message with erasure
Usage
#include <libkeccak.h> int libkeccak_hmac_update(struct libkeccak_state *state, const void *msg, size_t msglen);
Link with -lkeccak.
Overview
The libkeccak_hmac_update() function continues (or starts) HMAC-hashing a message. The current state of the hashing is stored in *state, and will be updated. The message specified by the msg parameter with the byte-size specified by the msglen parameter, will be hashed.
The libkeccak_hmac_update() function may reallocate the state's message chunk buffer. When doing so, it attempts to do so as securely as possible, rather than as fast as possible.
Return values
The libkeccak_hmac_update() function returns 0 upon successful completion. On error, -1 is returned and errno is set to describe the error.
Errors
The libkeccak_hmac_update() function may fail for any reason specified by the function malloc(3).
Notes
Neither parameter by be NULL or 0.