md5_hmac_ctx_init
md5_hmac_ctx_init(&ctx->hc_ctx_u.md5_ctx, md5_ipad, md5_opad);
void md5_hmac_ctx_init(md5_hc_ctx_t *, uint32_t *, uint32_t *);
md5_hmac_ctx_init(&md5_hmac_ctx, md5_ipad, md5_opad);