ssl_engine_init.c

apache服务器源代码（版本号：2.2.2）

    if (!(protocol & SSL_PROTOCOL_SSLV2)) {
        SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2);
    }

    if (!(protocol & SSL_PROTOCOL_SSLV3)) {
        SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv3);
    }

    if (!(protocol & SSL_PROTOCOL_TLSV1)) {
        SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1);
    }

#ifdef SSL_OP_CIPHER_SERVER_PREFERENCE
    {
        SSLSrvConfigRec *sc = mySrvConfig(s);
        if (sc->cipher_server_pref == TRUE) {
            SSL_CTX_set_options(ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
        }
    }
#endif

    SSL_CTX_set_app_data(ctx, s);

    /*
     * Configure additional context ingredients
     */
    SSL_CTX_set_options(ctx, SSL_OP_SINGLE_DH_USE);

#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
    /*
     * Disallow a session from being resumed during a renegotiation,
     * so that an acceptable cipher suite can be negotiated.
     */
    SSL_CTX_set_options(ctx, SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
#endif
}

static void ssl_init_ctx_session_cache(server_rec *s,
                                       apr_pool_t *p,
                                       apr_pool_t *ptemp,
                                       modssl_ctx_t *mctx)
{
    SSL_CTX *ctx = mctx->ssl_ctx;
    SSLModConfigRec *mc = myModConfig(s);
    long cache_mode = SSL_SESS_CACHE_OFF;
    if (mc->nSessionCacheMode != SSL_SCMODE_NONE) {
        /* SSL_SESS_CACHE_NO_INTERNAL will force OpenSSL
         * to ignore process local-caching and
         * to always get/set/delete sessions using mod_ssl's callbacks.
         */
        cache_mode = SSL_SESS_CACHE_SERVER|SSL_SESS_CACHE_NO_INTERNAL;
    }

    SSL_CTX_set_session_cache_mode(ctx, cache_mode);

    SSL_CTX_sess_set_new_cb(ctx,    ssl_callback_NewSessionCacheEntry);
    SSL_CTX_sess_set_get_cb(ctx,    ssl_callback_GetSessionCacheEntry);
    SSL_CTX_sess_set_remove_cb(ctx, ssl_callback_DelSessionCacheEntry);
}

static void ssl_init_ctx_callbacks(server_rec *s,
                                   apr_pool_t *p,
                                   apr_pool_t *ptemp,
                                   modssl_ctx_t *mctx)
{
    SSL_CTX *ctx = mctx->ssl_ctx;

    SSL_CTX_set_tmp_rsa_callback(ctx, ssl_callback_TmpRSA);
    SSL_CTX_set_tmp_dh_callback(ctx,  ssl_callback_TmpDH);

    if (s->loglevel >= APLOG_DEBUG) {
        /* this callback only logs if LogLevel >= info */
        SSL_CTX_set_info_callback(ctx, ssl_callback_LogTracingState);
    }
}

static void ssl_init_ctx_verify(server_rec *s,
                                apr_pool_t *p,
                                apr_pool_t *ptemp,
                                modssl_ctx_t *mctx)
{
    SSL_CTX *ctx = mctx->ssl_ctx;

    int verify = SSL_VERIFY_NONE;
    STACK_OF(X509_NAME) *ca_list;

    if (mctx->auth.verify_mode == SSL_CVERIFY_UNSET) {
        mctx->auth.verify_mode = SSL_CVERIFY_NONE;
    }

    if (mctx->auth.verify_depth == UNSET) {
        mctx->auth.verify_depth = 1;
    }

    /*
     *  Configure callbacks for SSL context
     */
    if (mctx->auth.verify_mode == SSL_CVERIFY_REQUIRE) {
        verify |= SSL_VERIFY_PEER_STRICT;
    }

    if ((mctx->auth.verify_mode == SSL_CVERIFY_OPTIONAL) ||
        (mctx->auth.verify_mode == SSL_CVERIFY_OPTIONAL_NO_CA))
    {
        verify |= SSL_VERIFY_PEER;
    }

    SSL_CTX_set_verify(ctx, verify, ssl_callback_SSLVerify);

    /*
     * Configure Client Authentication details
     */
    if (mctx->auth.ca_cert_file || mctx->auth.ca_cert_path) {
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                     "Configuring client authentication");

        if (!SSL_CTX_load_verify_locations(ctx,
                         MODSSL_PCHAR_CAST mctx->auth.ca_cert_file,
                         MODSSL_PCHAR_CAST mctx->auth.ca_cert_path))
        {
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                    "Unable to configure verify locations "
                    "for client authentication");
            ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
            ssl_die();
        }

        if (mctx->pks && (mctx->pks->ca_name_file || mctx->pks->ca_name_path)) {
            ca_list = ssl_init_FindCAList(s, ptemp,
                                          mctx->pks->ca_name_file,
                                          mctx->pks->ca_name_path);
        } else
            ca_list = ssl_init_FindCAList(s, ptemp,
                                          mctx->auth.ca_cert_file,
                                          mctx->auth.ca_cert_path);
        if (!ca_list) {
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                    "Unable to determine list of acceptable "
                    "CA certificates for client authentication");
            ssl_die();
        }

        SSL_CTX_set_client_CA_list(ctx, (STACK *)ca_list);
    }

    /*
     * Give a warning when no CAs were configured but client authentication
     * should take place. This cannot work.
     */
    if (mctx->auth.verify_mode == SSL_CVERIFY_REQUIRE) {
        ca_list = (STACK_OF(X509_NAME) *)SSL_CTX_get_client_CA_list(ctx);

        if (sk_X509_NAME_num(ca_list) == 0) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s,
                         "Init: Oops, you want to request client "
                         "authentication, but no CAs are known for "
                         "verification!?  [Hint: SSLCACertificate*]");
        }
    }
}

static void ssl_init_ctx_cipher_suite(server_rec *s,
                                      apr_pool_t *p,
                                      apr_pool_t *ptemp,
                                      modssl_ctx_t *mctx)
{
    SSL_CTX *ctx = mctx->ssl_ctx;
    const char *suite = mctx->auth.cipher_suite;

    /*
     *  Configure SSL Cipher Suite
     */
    if (!suite) {
        return;
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                 "Configuring permitted SSL ciphers [%s]",
                 suite);

    if (!SSL_CTX_set_cipher_list(ctx, MODSSL_PCHAR_CAST suite)) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                "Unable to configure permitted SSL ciphers");
        ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
        ssl_die();
    }
}

static void ssl_init_ctx_crl(server_rec *s,
                             apr_pool_t *p,
                             apr_pool_t *ptemp,
                             modssl_ctx_t *mctx)
{
    /*
     * Configure Certificate Revocation List (CRL) Details
     */

    if (!(mctx->crl_file || mctx->crl_path)) {
        return;
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                 "Configuring certificate revocation facility");

    mctx->crl =
        SSL_X509_STORE_create((char *)mctx->crl_file,
                              (char *)mctx->crl_path);

    if (!mctx->crl) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                "Unable to configure X.509 CRL storage "
                "for certificate revocation");
        ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
        ssl_die();
    }
}

static void ssl_init_ctx_cert_chain(server_rec *s,
                                    apr_pool_t *p,
                                    apr_pool_t *ptemp,
                                    modssl_ctx_t *mctx)
{
    BOOL skip_first = FALSE;
    int i, n;
    const char *chain = mctx->cert_chain;

    /*
     * Optionally configure extra server certificate chain certificates.
     * This is usually done by OpenSSL automatically when one of the
     * server cert issuers are found under SSLCACertificatePath or in
     * SSLCACertificateFile. But because these are intended for client
     * authentication it can conflict. For instance when you use a
     * Global ID server certificate you've to send out the intermediate
     * CA certificate, too. When you would just configure this with
     * SSLCACertificateFile and also use client authentication mod_ssl
     * would accept all clients also issued by this CA. Obviously this
     * isn't what we want in this situation. So this feature here exists
     * to allow one to explicity configure CA certificates which are
     * used only for the server certificate chain.
     */
    if (!chain) {
        return;
    }

    for (i = 0; (i < SSL_AIDX_MAX) && mctx->pks->cert_files[i]; i++) {
        if (strEQ(mctx->pks->cert_files[i], chain)) {
            skip_first = TRUE;
            break;
        }
    }

    n = SSL_CTX_use_certificate_chain(mctx->ssl_ctx,
                                      (char *)chain,
                                      skip_first, NULL);
    if (n < 0) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                "Failed to configure CA certificate chain!");
        ssl_die();
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                 "Configuring server certificate chain "
                 "(%d CA certificate%s)",
                 n, n == 1 ? "" : "s");
}

static void ssl_init_ctx(server_rec *s,
                         apr_pool_t *p,
                         apr_pool_t *ptemp,
                         modssl_ctx_t *mctx)
{
    ssl_init_ctx_protocol(s, p, ptemp, mctx);

    ssl_init_ctx_session_cache(s, p, ptemp, mctx);

    ssl_init_ctx_callbacks(s, p, ptemp, mctx);

    ssl_init_ctx_verify(s, p, ptemp, mctx);

    ssl_init_ctx_cipher_suite(s, p, ptemp, mctx);

    ssl_init_ctx_crl(s, p, ptemp, mctx);

    if (mctx->pks) {
        /* XXX: proxy support? */
        ssl_init_ctx_cert_chain(s, p, ptemp, mctx);
    }
}

static int ssl_server_import_cert(server_rec *s,
                                  modssl_ctx_t *mctx,
                                  const char *id,
                                  int idx)
{
    SSLModConfigRec *mc = myModConfig(s);
    ssl_asn1_t *asn1;
    MODSSL_D2I_X509_CONST unsigned char *ptr;
    const char *type = ssl_asn1_keystr(idx);
    X509 *cert;

    if (!(asn1 = ssl_asn1_table_get(mc->tPublicCert, id))) {
        return FALSE;
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                 "Configuring %s server certificate", type);

    ptr = asn1->cpData;
    if (!(cert = d2i_X509(NULL, &ptr, asn1->nData))) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                "Unable to import %s server certificate", type);
        ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
        ssl_die();
    }

    if (SSL_CTX_use_certificate(mctx->ssl_ctx, cert) <= 0) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                "Unable to configure %s server certificate", type);
        ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
        ssl_die();
    }

    mctx->pks->certs[idx] = cert;

    return TRUE;
}

static int ssl_server_import_key(server_rec *s,
                                 modssl_ctx_t *mctx,
                                 const char *id,
                                 int idx)
{
    SSLModConfigRec *mc = myModConfig(s);
    ssl_asn1_t *asn1;
    MODSSL_D2I_PrivateKey_CONST unsigned char *ptr;
    const char *type = ssl_asn1_keystr(idx);
    int pkey_type = (idx == SSL_AIDX_RSA) ? EVP_PKEY_RSA : EVP_PKEY_DSA;
    EVP_PKEY *pkey;

    if (!(asn1 = ssl_asn1_table_get(mc->tPrivateKey, id))) {
        return FALSE;
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                 "Configuring %s server private key", type);

    ptr = asn1->cpData;
    if (!(pkey = d2i_PrivateKey(pkey_type, NULL, &ptr, asn1->nData)))
    {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                "Unable to import %s server private key", type);
        ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
        ssl_die();
    }

    if (SSL_CTX_use_PrivateKey(mctx->ssl_ctx, pkey) <= 0) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                "Unable to configure %s server private key", type);
        ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
        ssl_die();
    }

    /*
     * XXX: wonder if this is still needed, this is old todo doc.
     * (see http://www.psy.uq.edu.au/~ftp/Crypto/ssleay/TODO.html)
     */
    if ((pkey_type == EVP_PKEY_DSA) && mctx->pks->certs[idx]) {
        EVP_PKEY *pubkey = X509_get_pubkey(mctx->pks->certs[idx]);

        if (pubkey && EVP_PKEY_missing_parameters(pubkey)) {
            EVP_PKEY_copy_parameters(pubkey, pkey);
            ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
                    "Copying DSA parameters from private key to certificate");
            ssl_log_ssl_error(APLOG_MARK, APLOG_ERR, s);
            EVP_PKEY_free(pubkey);
        }
    }

    mctx->pks->keys[idx] = pkey;

    return TRUE;
}

static void ssl_check_public_cert(server_rec *s,
                                  apr_pool_t *ptemp,
                                  X509 *cert,
                                  int type)
{
    int is_ca, pathlen;
    char *cn;

    if (!cert) {
        return;
    }

    /*
     * Some information about the certificate(s)
     */

    if (SSL_X509_isSGC(cert)) {
        ap_log_error(APLOG_MARK, APLOG_INFO, 0, s,
                     "%s server certificate enables "
                     "Server Gated Cryptography (SGC)",
                     ssl_asn1_keystr(type));
    }

    if (SSL_X509_getBC(cert, &is_ca, &pathlen)) {
        if (is_ca) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s,
                         "%s server certificate is a CA certificate "
                         "(BasicConstraints: CA == TRUE !?)",
                         ssl_asn1_keystr(type));
        }

        if (pathlen > 0) {
            ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s,
                         "%s server certificate is not a leaf certificate "
                         "(BasicConstraints: pathlen == %d > 0 !?)",
                         ssl_asn1_keystr(type), pathlen);
        }
    }

    if (SSL_X509_getCN(ptemp, cert, &cn)) {
        int fnm_flags = APR_FNM_PERIOD|APR_FNM_CASE_BLIND;