sha1_hmac_ctx_init
sha1_hmac_ctx_init(&ctx->hc_ctx_u.sha1_ctx, sha1_ipad,
void sha1_hmac_ctx_init(sha1_hc_ctx_t *, uint32_t *, uint32_t *);
sha1_hmac_ctx_init(&sha1_hmac_ctx, sha1_ipad, sha1_opad);