int ssl3_get_cert_verify(SSL *s)
{
    EVP_PKEY *pkey = NULL;
    unsigned char *p;
    int al, ok, ret = 0;
    long n;
    int type = 0, i, j;
    X509 *peer;
    const EVP_MD *md = NULL;
    EVP_MD_CTX mctx;
    EVP_MD_CTX_init(&mctx);
    n = s->method->ssl_get_message(s,
                                   SSL3_ST_SR_CERT_VRFY_A,
                                   SSL3_ST_SR_CERT_VRFY_B,
                                   -1, SSL3_RT_MAX_PLAIN_LENGTH, &ok);
    if (!ok)
        return ((int)n);
    if (s->session->peer != NULL) {
        peer = s->session->peer;
        pkey = X509_get_pubkey(peer);
        type = X509_certificate_type(peer, pkey);
    } else {
        peer = NULL;
        pkey = NULL;
    }
    if (s->s3->tmp.message_type != SSL3_MT_CERTIFICATE_VERIFY) {
        s->s3->tmp.reuse_message = 1;
        if (peer != NULL) {
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_MISSING_VERIFY_MESSAGE);
            goto f_err;
        }
        ret = 1;
        goto end;
    }
    if (peer == NULL) {
        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_NO_CLIENT_CERT_RECEIVED);
        al = SSL_AD_UNEXPECTED_MESSAGE;
        goto f_err;
    }
    if (!(type & EVP_PKT_SIGN)) {
        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY,
               SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);
        al = SSL_AD_ILLEGAL_PARAMETER;
        goto f_err;
    }
    if (s->s3->change_cipher_spec) {
        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_CCS_RECEIVED_EARLY);
        al = SSL_AD_UNEXPECTED_MESSAGE;
        goto f_err;
    }
    p = (unsigned char *)s->init_msg;
    if (n == 64 && (pkey->type == NID_id_GostR3410_94 ||
                    pkey->type == NID_id_GostR3410_2001)) {
        i = 64;
    } else {
        if (SSL_USE_SIGALGS(s)) {
            int rv = tls12_check_peer_sigalg(&md, s, p, 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
            p += 2;
            n -= 2;
        }
        n2s(p, i);
        n -= 2;
        if (i > n) {
            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);
            al = SSL_AD_DECODE_ERROR;
            goto f_err;
        }
    }
    j = EVP_PKEY_size(pkey);
    if ((i > j) || (n > j) || (n <= 0)) {
        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_WRONG_SIGNATURE_SIZE);
        al = SSL_AD_DECODE_ERROR;
        goto f_err;
    }
    if (SSL_USE_SIGALGS(s)) {
        long hdatalen = 0;
        void *hdata;
        hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
        if (hdatalen <= 0) {
            SSLerr(SSL_F_SSL3_GET_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 (!EVP_VerifyInit_ex(&mctx, md, NULL)
            || !EVP_VerifyUpdate(&mctx, hdata, hdatalen)) {
            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, ERR_R_EVP_LIB);
            al = SSL_AD_INTERNAL_ERROR;
            goto f_err;
        }
        if (EVP_VerifyFinal(&mctx, p, i, pkey) <= 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_SSL3_GET_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, p, i,
                       pkey->pkey.rsa);
        if (i < 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_BAD_RSA_DECRYPT);
            goto f_err;
        }
        if (i == 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_SSL3_GET_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, p, i, pkey->pkey.dsa);
        if (j <= 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_BAD_DSA_SIGNATURE);
            goto f_err;
        }
    } else
#endif
#ifndef OPENSSL_NO_ECDSA
    if (pkey->type == EVP_PKEY_EC) {
        j = ECDSA_verify(pkey->save_type,
                         &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]),
                         SHA_DIGEST_LENGTH, p, i, pkey->pkey.ec);
        if (j <= 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_BAD_ECDSA_SIGNATURE);
            goto f_err;
        }
    } else
#endif
    if (pkey->type == NID_id_GostR3410_94
            || pkey->type == NID_id_GostR3410_2001) {
        unsigned char signature[64];
        int idx;
        EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new(pkey, NULL);
        EVP_PKEY_verify_init(pctx);
        if (i != 64) {
            fprintf(stderr, "GOST signature length is %d", i);
        }
        for (idx = 0; idx < 64; idx++) {
            signature[63 - idx] = p[idx];
        }
        j = EVP_PKEY_verify(pctx, signature, 64, s->s3->tmp.cert_verify_md,
                            32);
        EVP_PKEY_CTX_free(pctx);
        if (j <= 0) {
            al = SSL_AD_DECRYPT_ERROR;
            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_BAD_ECDSA_SIGNATURE);
            goto f_err;
        }
    } else {
        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
        al = SSL_AD_UNSUPPORTED_CERTIFICATE;
        goto f_err;
    }
    ret = 1;
    if (0) {
 f_err:
        ssl3_send_alert(s, SSL3_AL_FATAL, al);
    }
 end:
    if (s->s3->handshake_buffer) {
        BIO_free(s->s3->handshake_buffer);
        s->s3->handshake_buffer = NULL;
        s->s3->flags &= ~TLS1_FLAGS_KEEP_HANDSHAKE;
    }
    EVP_MD_CTX_cleanup(&mctx);
    EVP_PKEY_free(pkey);
    return (ret);
}
['int ssl3_get_cert_verify(SSL *s)\n{\n    EVP_PKEY *pkey = NULL;\n    unsigned char *p;\n    int al, ok, ret = 0;\n    long n;\n    int type = 0, i, j;\n    X509 *peer;\n    const EVP_MD *md = NULL;\n    EVP_MD_CTX mctx;\n    EVP_MD_CTX_init(&mctx);\n    n = s->method->ssl_get_message(s,\n                                   SSL3_ST_SR_CERT_VRFY_A,\n                                   SSL3_ST_SR_CERT_VRFY_B,\n                                   -1, SSL3_RT_MAX_PLAIN_LENGTH, &ok);\n    if (!ok)\n        return ((int)n);\n    if (s->session->peer != NULL) {\n        peer = s->session->peer;\n        pkey = X509_get_pubkey(peer);\n        type = X509_certificate_type(peer, pkey);\n    } else {\n        peer = NULL;\n        pkey = NULL;\n    }\n    if (s->s3->tmp.message_type != SSL3_MT_CERTIFICATE_VERIFY) {\n        s->s3->tmp.reuse_message = 1;\n        if (peer != NULL) {\n            al = SSL_AD_UNEXPECTED_MESSAGE;\n            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_MISSING_VERIFY_MESSAGE);\n            goto f_err;\n        }\n        ret = 1;\n        goto end;\n    }\n    if (peer == NULL) {\n        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_NO_CLIENT_CERT_RECEIVED);\n        al = SSL_AD_UNEXPECTED_MESSAGE;\n        goto f_err;\n    }\n    if (!(type & EVP_PKT_SIGN)) {\n        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY,\n               SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);\n        al = SSL_AD_ILLEGAL_PARAMETER;\n        goto f_err;\n    }\n    if (s->s3->change_cipher_spec) {\n        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_CCS_RECEIVED_EARLY);\n        al = SSL_AD_UNEXPECTED_MESSAGE;\n        goto f_err;\n    }\n    p = (unsigned char *)s->init_msg;\n    if (n == 64 && (pkey->type == NID_id_GostR3410_94 ||\n                    pkey->type == NID_id_GostR3410_2001)) {\n        i = 64;\n    } else {\n        if (SSL_USE_SIGALGS(s)) {\n            int rv = tls12_check_peer_sigalg(&md, s, p, 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            p += 2;\n            n -= 2;\n        }\n        n2s(p, i);\n        n -= 2;\n        if (i > n) {\n            SSLerr(SSL_F_SSL3_GET_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 ((i > j) || (n > j) || (n <= 0)) {\n        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_WRONG_SIGNATURE_SIZE);\n        al = SSL_AD_DECODE_ERROR;\n        goto f_err;\n    }\n    if (SSL_USE_SIGALGS(s)) {\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_SSL3_GET_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 (!EVP_VerifyInit_ex(&mctx, md, NULL)\n            || !EVP_VerifyUpdate(&mctx, hdata, hdatalen)) {\n            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, ERR_R_EVP_LIB);\n            al = SSL_AD_INTERNAL_ERROR;\n            goto f_err;\n        }\n        if (EVP_VerifyFinal(&mctx, p, i, pkey) <= 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_SSL3_GET_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, p, i,\n                       pkey->pkey.rsa);\n        if (i < 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_SSL3_GET_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_SSL3_GET_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, p, i, pkey->pkey.dsa);\n        if (j <= 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_BAD_DSA_SIGNATURE);\n            goto f_err;\n        }\n    } else\n#endif\n#ifndef OPENSSL_NO_ECDSA\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, p, i, pkey->pkey.ec);\n        if (j <= 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_BAD_ECDSA_SIGNATURE);\n            goto f_err;\n        }\n    } else\n#endif\n    if (pkey->type == NID_id_GostR3410_94\n            || pkey->type == NID_id_GostR3410_2001) {\n        unsigned char signature[64];\n        int idx;\n        EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new(pkey, NULL);\n        EVP_PKEY_verify_init(pctx);\n        if (i != 64) {\n            fprintf(stderr, "GOST signature length is %d", i);\n        }\n        for (idx = 0; idx < 64; idx++) {\n            signature[63 - idx] = p[idx];\n        }\n        j = EVP_PKEY_verify(pctx, signature, 64, s->s3->tmp.cert_verify_md,\n                            32);\n        EVP_PKEY_CTX_free(pctx);\n        if (j <= 0) {\n            al = SSL_AD_DECRYPT_ERROR;\n            SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, SSL_R_BAD_ECDSA_SIGNATURE);\n            goto f_err;\n        }\n    } else {\n        SSLerr(SSL_F_SSL3_GET_CERT_VERIFY, ERR_R_INTERNAL_ERROR);\n        al = SSL_AD_UNSUPPORTED_CERTIFICATE;\n        goto f_err;\n    }\n    ret = 1;\n    if (0) {\n f_err:\n        ssl3_send_alert(s, SSL3_AL_FATAL, al);\n    }\n end:\n    if (s->s3->handshake_buffer) {\n        BIO_free(s->s3->handshake_buffer);\n        s->s3->handshake_buffer = NULL;\n        s->s3->flags &= ~TLS1_FLAGS_KEEP_HANDSHAKE;\n    }\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) || (x->cert_info == NULL))\n        return (NULL);\n    return (X509_PUBKEY_get(x->cert_info->key));\n}']