MSG_PROCESS_RETURN tls_process_cert_verify(SSL *s, PACKET *pkt)
{
    EVP_PKEY *pkey = NULL;
    unsigned char *sig, *data;
    int al, ret = MSG_PROCESS_ERROR;
    int type = 0, i, j;
    unsigned int len;
    X509 *peer;
    const EVP_MD *md = NULL;
    EVP_MD_CTX mctx;
    EVP_MD_CTX_init(&mctx);
    peer = s->session->peer;
    pkey = X509_get_pubkey(peer);
    type = X509_certificate_type(peer, pkey);
    if (!(type & EVP_PKT_SIGN)) {
        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY,
               SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);
        al = SSL_AD_ILLEGAL_PARAMETER;
        goto f_err;
    }
    if (PACKET_remaining(pkt) == 64 && pkey->type == NID_id_GostR3410_2001) {
        len = 64;
    } else {
        if (SSL_USE_SIGALGS(s)) {
            int rv;
            if (!PACKET_get_bytes(pkt, &sig, 2)) {
                al = SSL_AD_DECODE_ERROR;
                goto f_err;
            }
            rv = tls12_check_peer_sigalg(&md, s, sig, pkey);
            if (rv == -1) {
                al = SSL_AD_INTERNAL_ERROR;
                goto f_err;
            } else if (rv == 0) {
                al = SSL_AD_DECODE_ERROR;
                goto f_err;
            }
#ifdef SSL_DEBUG
            fprintf(stderr, "USING TLSv1.2 HASH %s\n", EVP_MD_name(md));
#endif
        }
        if (!PACKET_get_net_2(pkt, &len)) {
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);
            al = SSL_AD_DECODE_ERROR;
            goto f_err;
        }
    }
    j = EVP_PKEY_size(pkey);
    if (((int)len > j) || ((int)PACKET_remaining(pkt) > j)
            || (PACKET_remaining(pkt) == 0)) {
        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_WRONG_SIGNATURE_SIZE);
        al = SSL_AD_DECODE_ERROR;
        goto f_err;
    }
    if (!PACKET_get_bytes(pkt, &data, len)) {
        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);
        al = SSL_AD_DECODE_ERROR;
        goto f_err;
    }
    if (SSL_USE_SIGALGS(s)
            || pkey->type == NID_id_GostR3410_2001
            || pkey->type == NID_id_GostR3410_2012_256
            || pkey->type == NID_id_GostR3410_2012_512) {
        long hdatalen = 0;
        void *hdata;
        hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
        if (hdatalen <= 0) {
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
            al = SSL_AD_INTERNAL_ERROR;
            goto f_err;
        }
#ifdef SSL_DEBUG
        fprintf(stderr, "Using TLS 1.2 with client verify alg %s\n",
                EVP_MD_name(md));
#endif
        if (!SSL_USE_SIGALGS(s)) {
            int dgst_nid;
            if (EVP_PKEY_get_default_digest_nid(pkey, &dgst_nid) <= 0
                || (md = EVP_get_digestbynid(dgst_nid)) == NULL) {
                SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
                al = SSL_AD_INTERNAL_ERROR;
                goto f_err;
            }
        }
        if (!EVP_VerifyInit_ex(&mctx, md, NULL)
            || !EVP_VerifyUpdate(&mctx, hdata, hdatalen)) {
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_EVP_LIB);
            al = SSL_AD_INTERNAL_ERROR;
            goto f_err;
        }
        if (pkey->type == NID_id_GostR3410_2001
                || pkey->type == NID_id_GostR3410_2012_256
                || pkey->type == NID_id_GostR3410_2012_512) {
            unsigned int j1, j2;
            for (j1 = len - 1, j2 = 0; j2 < len/2; j2++, j1--) {
                char c = data[j2];
                data[j2] = data[j1];
                data[j1] = c;
            }
        }
        if (EVP_VerifyFinal(&mctx, data, len, pkey) <= 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_SIGNATURE);
            goto f_err;
        }
    } else
#ifndef OPENSSL_NO_RSA
    if (pkey->type == EVP_PKEY_RSA) {
        i = RSA_verify(NID_md5_sha1, s->s3->tmp.cert_verify_md,
                       MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, data, len,
                       pkey->pkey.rsa);
        if (i < 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_RSA_DECRYPT);
            goto f_err;
        }
        if (i == 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_RSA_SIGNATURE);
            goto f_err;
        }
    } else
#endif
#ifndef OPENSSL_NO_DSA
    if (pkey->type == EVP_PKEY_DSA) {
        j = DSA_verify(pkey->save_type,
                       &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]),
                       SHA_DIGEST_LENGTH, data, len, pkey->pkey.dsa);
        if (j <= 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_DSA_SIGNATURE);
            goto f_err;
        }
    } else
#endif
#ifndef OPENSSL_NO_EC
    if (pkey->type == EVP_PKEY_EC) {
        j = ECDSA_verify(pkey->save_type,
                         &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]),
                         SHA_DIGEST_LENGTH, data, len, pkey->pkey.ec);
        if (j <= 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_ECDSA_SIGNATURE);
            goto f_err;
        }
    } else
#endif
    {
        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
        al = SSL_AD_UNSUPPORTED_CERTIFICATE;
        goto f_err;
    }
    ret = MSG_PROCESS_CONTINUE_PROCESSING;
    if (0) {
 f_err:
        ssl3_send_alert(s, SSL3_AL_FATAL, al);
        ossl_statem_set_error(s);
    }
    BIO_free(s->s3->handshake_buffer);
    s->s3->handshake_buffer = NULL;
    EVP_MD_CTX_cleanup(&mctx);
    EVP_PKEY_free(pkey);
    return ret;
}
['MSG_PROCESS_RETURN tls_process_cert_verify(SSL *s, PACKET *pkt)\n{\n    EVP_PKEY *pkey = NULL;\n    unsigned char *sig, *data;\n    int al, ret = MSG_PROCESS_ERROR;\n    int type = 0, i, j;\n    unsigned int len;\n    X509 *peer;\n    const EVP_MD *md = NULL;\n    EVP_MD_CTX mctx;\n    EVP_MD_CTX_init(&mctx);\n    peer = s->session->peer;\n    pkey = X509_get_pubkey(peer);\n    type = X509_certificate_type(peer, pkey);\n    if (!(type & EVP_PKT_SIGN)) {\n        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY,\n               SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);\n        al = SSL_AD_ILLEGAL_PARAMETER;\n        goto f_err;\n    }\n    if (PACKET_remaining(pkt) == 64 && pkey->type == NID_id_GostR3410_2001) {\n        len = 64;\n    } else {\n        if (SSL_USE_SIGALGS(s)) {\n            int rv;\n            if (!PACKET_get_bytes(pkt, &sig, 2)) {\n                al = SSL_AD_DECODE_ERROR;\n                goto f_err;\n            }\n            rv = tls12_check_peer_sigalg(&md, s, sig, pkey);\n            if (rv == -1) {\n                al = SSL_AD_INTERNAL_ERROR;\n                goto f_err;\n            } else if (rv == 0) {\n                al = SSL_AD_DECODE_ERROR;\n                goto f_err;\n            }\n#ifdef SSL_DEBUG\n            fprintf(stderr, "USING TLSv1.2 HASH %s\\n", EVP_MD_name(md));\n#endif\n        }\n        if (!PACKET_get_net_2(pkt, &len)) {\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);\n            al = SSL_AD_DECODE_ERROR;\n            goto f_err;\n        }\n    }\n    j = EVP_PKEY_size(pkey);\n    if (((int)len > j) || ((int)PACKET_remaining(pkt) > j)\n            || (PACKET_remaining(pkt) == 0)) {\n        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_WRONG_SIGNATURE_SIZE);\n        al = SSL_AD_DECODE_ERROR;\n        goto f_err;\n    }\n    if (!PACKET_get_bytes(pkt, &data, len)) {\n        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);\n        al = SSL_AD_DECODE_ERROR;\n        goto f_err;\n    }\n    if (SSL_USE_SIGALGS(s)\n            || pkey->type == NID_id_GostR3410_2001\n            || pkey->type == NID_id_GostR3410_2012_256\n            || pkey->type == NID_id_GostR3410_2012_512) {\n        long hdatalen = 0;\n        void *hdata;\n        hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);\n        if (hdatalen <= 0) {\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);\n            al = SSL_AD_INTERNAL_ERROR;\n            goto f_err;\n        }\n#ifdef SSL_DEBUG\n        fprintf(stderr, "Using TLS 1.2 with client verify alg %s\\n",\n                EVP_MD_name(md));\n#endif\n        if (!SSL_USE_SIGALGS(s)) {\n            int dgst_nid;\n            if (EVP_PKEY_get_default_digest_nid(pkey, &dgst_nid) <= 0\n                || (md = EVP_get_digestbynid(dgst_nid)) == NULL) {\n                SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);\n                al = SSL_AD_INTERNAL_ERROR;\n                goto f_err;\n            }\n        }\n        if (!EVP_VerifyInit_ex(&mctx, md, NULL)\n            || !EVP_VerifyUpdate(&mctx, hdata, hdatalen)) {\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_EVP_LIB);\n            al = SSL_AD_INTERNAL_ERROR;\n            goto f_err;\n        }\n        if (pkey->type == NID_id_GostR3410_2001\n                || pkey->type == NID_id_GostR3410_2012_256\n                || pkey->type == NID_id_GostR3410_2012_512) {\n            unsigned int j1, j2;\n            for (j1 = len - 1, j2 = 0; j2 < len/2; j2++, j1--) {\n                char c = data[j2];\n                data[j2] = data[j1];\n                data[j1] = c;\n            }\n        }\n        if (EVP_VerifyFinal(&mctx, data, len, pkey) <= 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_SIGNATURE);\n            goto f_err;\n        }\n    } else\n#ifndef OPENSSL_NO_RSA\n    if (pkey->type == EVP_PKEY_RSA) {\n        i = RSA_verify(NID_md5_sha1, s->s3->tmp.cert_verify_md,\n                       MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH, data, len,\n                       pkey->pkey.rsa);\n        if (i < 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_RSA_DECRYPT);\n            goto f_err;\n        }\n        if (i == 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_RSA_SIGNATURE);\n            goto f_err;\n        }\n    } else\n#endif\n#ifndef OPENSSL_NO_DSA\n    if (pkey->type == EVP_PKEY_DSA) {\n        j = DSA_verify(pkey->save_type,\n                       &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]),\n                       SHA_DIGEST_LENGTH, data, len, pkey->pkey.dsa);\n        if (j <= 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_DSA_SIGNATURE);\n            goto f_err;\n        }\n    } else\n#endif\n#ifndef OPENSSL_NO_EC\n    if (pkey->type == EVP_PKEY_EC) {\n        j = ECDSA_verify(pkey->save_type,\n                         &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]),\n                         SHA_DIGEST_LENGTH, data, len, pkey->pkey.ec);\n        if (j <= 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_ECDSA_SIGNATURE);\n            goto f_err;\n        }\n    } else\n#endif\n    {\n        SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);\n        al = SSL_AD_UNSUPPORTED_CERTIFICATE;\n        goto f_err;\n    }\n    ret = MSG_PROCESS_CONTINUE_PROCESSING;\n    if (0) {\n f_err:\n        ssl3_send_alert(s, SSL3_AL_FATAL, al);\n        ossl_statem_set_error(s);\n    }\n    BIO_free(s->s3->handshake_buffer);\n    s->s3->handshake_buffer = NULL;\n    EVP_MD_CTX_cleanup(&mctx);\n    EVP_PKEY_free(pkey);\n    return ret;\n}', 'void EVP_MD_CTX_init(EVP_MD_CTX *ctx)\n{\n    memset(ctx, 0, sizeof(*ctx));\n}', 'EVP_PKEY *X509_get_pubkey(X509 *x)\n{\n    if (x == NULL)\n        return (NULL);\n    return (X509_PUBKEY_get(x->cert_info.key));\n}', 'static inline size_t PACKET_remaining(const PACKET *pkt)\n{\n    return pkt->remaining;\n}']