Add --insecure option to command line tools. (redis#8416)

Disable certificate validation, making it possible to connect to servers
without configuring full trust chain.

The use of this option is insecure and makes the connection vulnerable
to man in the middle attacks.

src/cli_common.c

@@ -54,7 +54,7 @@ int cliSecureConnection(redisContext *c, cliSSLconfig config, const char **err)
             goto error;
         }
         SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
-        SSL_CTX_set_verify(ssl_ctx, SSL_VERIFY_PEER, NULL);
+        SSL_CTX_set_verify(ssl_ctx, config.skip_cert_verify ? SSL_VERIFY_NONE : SSL_VERIFY_PEER, NULL);
 
         if (config.cacert || config.cacertdir) {
             if (!SSL_CTX_load_verify_locations(ssl_ctx, config.cacert, config.cacertdir)) {

src/cli_common.h

@@ -10,6 +10,8 @@ typedef struct cliSSLconfig {
     char *cacert;
     /* Directory where trusted CA certificates are stored, or NULL */
     char *cacertdir;
+    /* Skip server certificate verification. */
+    int skip_cert_verify;
     /* Client certificate to authenticate with, or NULL */
     char *cert;
     /* Private key file to authenticate with, or NULL */

src/redis-benchmark.c

@@ -1516,6 +1516,8 @@ int parseOptions(int argc, const char **argv) {
         } else if (!strcmp(argv[i],"--cacert")) {
             if (lastarg) goto invalid;
             config.sslconfig.cacert = strdup(argv[++i]);
+        } else if (!strcmp(argv[i],"--insecure")) {
+            config.sslconfig.skip_cert_verify = 1;
         } else if (!strcmp(argv[i],"--cert")) {
             if (lastarg) goto invalid;
             config.sslconfig.cert = strdup(argv[++i]);
@@ -1585,6 +1587,7 @@ int parseOptions(int argc, const char **argv) {
 " --cacertdir <dir>  Directory where trusted CA certificates are stored.\n"
 "                    If neither cacert nor cacertdir are specified, the default\n"
 "                    system-wide trusted root certs configuration will apply.\n"
+" --insecure         Allow insecure TLS connection by skipping cert validation.\n"
 " --cert <file>      Client certificate to authenticate with.\n"
 " --key <file>       Private key file to authenticate with.\n"
 " --tls-ciphers <list> Sets the list of prefered ciphers (TLSv1.2 and below)\n"
@@ -1682,6 +1685,7 @@ int main(int argc, const char **argv) {
     signal(SIGHUP, SIG_IGN);
     signal(SIGPIPE, SIG_IGN);
 
+    memset(&config.sslconfig, 0, sizeof(config.sslconfig));
     config.numclients = 50;
     config.requests = 100000;
     config.liveclients = 0;

src/redis-cli.c

@@ -1695,6 +1695,8 @@ static int parseOptions(int argc, char **argv) {
             config.sslconfig.key = argv[++i];
         } else if (!strcmp(argv[i],"--tls-ciphers") && !lastarg) {
             config.sslconfig.ciphers = argv[++i];
+        } else if (!strcmp(argv[i],"--insecure")) {
+            config.sslconfig.skip_cert_verify = 1;
         #ifdef TLS1_3_VERSION
         } else if (!strcmp(argv[i],"--tls-ciphersuites") && !lastarg) {
             config.sslconfig.ciphersuites = argv[++i];
@@ -1820,6 +1822,7 @@ static void usage(void) {
 "  --cacertdir <dir>  Directory where trusted CA certificates are stored.\n"
 "                     If neither cacert nor cacertdir are specified, the default\n"
 "                     system-wide trusted root certs configuration will apply.\n"
+"  --insecure         Allow insecure TLS connection by skipping cert validation.\n"
 "  --cert <file>      Client certificate to authenticate with.\n"
 "  --key <file>       Private key file to authenticate with.\n"
 "  --tls-ciphers <list> Sets the list of prefered ciphers (TLSv1.2 and below)\n"
@@ -8131,6 +8134,7 @@ int main(int argc, char **argv) {
     int firstarg;
     struct timeval tv;
 
+    memset(&config.sslconfig, 0, sizeof(config.sslconfig));
     config.hostip = sdsnew("127.0.0.1");
     config.hostport = 6379;
     config.hostsocket = NULL;