Bug#17208 SSL: client does not verify server certificate

- Add new function 'ssl_verify_server_cert' which is used if we are connecting to the server with SSL. It will compare the hostname in the server's cert against the hostname that we used when connecting to the server. Will reject the connection if hostname does not match. - Add new option "OPT_SSL_VERIFY_SERVER_CERT" to be passed to mysql_options which will turn on checking of servers cert. - Add new argument "ssl-verify-server-cert" to all mysql* clients which will activate the above option. - Generate a new server cert with 1024 bits that has "localhost" as the server name. SSL/server-cert.pem: Generate a new server cert that has "localhost" as CN, so that we can test to verify the hostname we connected against with the hostname in the cert client/client_priv.h: Add OPT_SSL_VERIFY_CERT client/mysql.cc: Pass the variable "opt_ssl_verify_server_cert" to the mysql_options function. It's processed/included by include/sslopt*.h files client/mysqladmin.cc: Pass the variable "opt_ssl_verify_server_cert" to the mysql_options function. It's processed/included by include/sslopt*.h files client/mysqldump.c: Pass the variable "opt_ssl_verify_server_cert" to the mysql_options function. It's processed/included by include/sslopt*.h files client/mysqlimport.c: Pass the variable "opt_ssl_verify_server_cert" to the mysql_options function. It's processed/included by include/sslopt*.h files client/mysqlshow.c: Pass the variable "opt_ssl_verify_server_cert" to the mysql_options function. It's processed/included by include/sslopt*.h files client/mysqltest.c: Always set opt_ssl_verify_server_cert on in mysqltest if we are using SSL include/mysql.h: Add variable ssl_verify_cerver_cert include/sslopt-longopts.h: Add ssl-verify-server-cert options to all clients. include/sslopt-vars.h: Add opt_ssl_varify_server_cert to all clients. sql-common/client.c: Add ssl_vertify_server_cert function which is executed if user has set the option ssl_verify_cerver_cert vio/viosslfactories.c: Ask the SSL library to verify servers cert by setting the SSL_VERIFY_PEER flag
2025-03-29 18:35:35 +01:00 · 2006-04-18 17:58:27 +02:00 · 2006-04-18 17:58:27 +02:00 · c1d64ccc1b
commit c1d64ccc1b
parent c3babee88a
13 changed files with 159 additions and 50 deletions
--- a/SSL/server-cert.pem
+++ b/SSL/server-cert.pem
@ -1,13 +1,14 @@
 Certificate:
    Data:
        Version: 3 (0x2)
-        Serial Number: 2 (0x2)
+        Serial Number:
+            e9:07:d1:01:94:ee:66:ca
        Signature Algorithm: md5WithRSAEncryption
-        Issuer: C=SE, L=Uppsala, O=MySQL AB, CN=Abstract MySQL Developer/Email=abstract.mysql.developer@mysql.com
+        Issuer: C=SE, ST=Uppsala, L=Uppsala, O=MySQL AB, CN=localhost/emailAddress=abstract.mysql.developer@mysql.com
        Validity
-            Not Before: Sep 12 16:22:06 2003 GMT
-            Not After : Sep  9 16:22:06 2013 GMT
-        Subject: C=SE, L=Uppsala, O=MySQL AB, CN=MySQL Server/Email=abstract.mysql.developer@mysql.com
+            Not Before: Apr 18 15:35:37 2006 GMT
+            Not After : Jan 12 15:35:37 2009 GMT
+        Subject: C=SE, ST=Uppsala, L=Uppsala, O=MySQL AB, CN=localhost/emailAddress=abstract.mysql.developer@mysql.com
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
            RSA Public Key: (1024 bit)
@ -23,45 +24,42 @@ Certificate:
                    3d:0e:4d:2a:a8:b8:ca:99:8d
                Exponent: 65537 (0x10001)
        X509v3 extensions:
-            X509v3 Basic Constraints: 
-                CA:FALSE
-            Netscape Comment: 
-                OpenSSL Generated Certificate
            X509v3 Subject Key Identifier: 
                6E:E4:9B:6A:C5:EA:E4:E6:C7:EF:D7:1E:C8:63:45:60:2B:1B:D4:D4
            X509v3 Authority Key Identifier: 
-                keyid:88:98:65:D9:F3:F2:8B:03:1D:66:60:61:23:FA:AD:73:6D:D3:68:92
-                DirName:/C=SE/L=Uppsala/O=MySQL AB/CN=Abstract MySQL Developer/Email=abstract.mysql.developer@mysql.com
-                serial:00
+                keyid:6E:E4:9B:6A:C5:EA:E4:E6:C7:EF:D7:1E:C8:63:45:60:2B:1B:D4:D4
+                DirName:/C=SE/ST=Uppsala/L=Uppsala/O=MySQL AB/CN=localhost/emailAddress=abstract.mysql.developer@mysql.com
+                serial:E9:07:D1:01:94:EE:66:CA

+            X509v3 Basic Constraints: 
+                CA:TRUE
    Signature Algorithm: md5WithRSAEncryption
-        31:77:69:b9:bd:ab:29:f3:fc:5a:09:16:6f:5d:42:ea:ba:01:
-        55:69:e3:75:cf:b8:d1:b7:b9:bf:da:63:85:8c:48:92:06:60:
-        76:97:e0:00:78:4b:ad:da:ab:6a:90:6d:8b:03:a8:b1:e9:09:
-        78:e1:29:98:56:12:60:6b:42:fe:e8:a7:c4:f8:d6:15:07:e8:
-        2b:c2:d8:8a:e5:1b:2e:51:08:9b:56:e3:b3:7a:4c:3e:e5:be:
-        4a:4d:f8:65:7b:a8:21:e0:ca:fe:8b:ab:d7:ec:f2:2d:f7:d0:
-        bf:d7:c5:23:1c:08:d8:aa:57:c7:f3:5f:ba:33:3f:78:d1:f4:
-        8e:5e
+        1f:03:59:6e:ff:1f:9d:c7:19:9e:8e:b2:1a:c0:0b:9e:ee:94:
+        35:77:2a:93:04:ea:d5:a8:fc:36:5a:5b:e3:1c:02:b8:cf:04:
+        6e:21:b0:27:f6:96:6e:d6:8f:cd:02:cf:23:f3:e7:ff:6a:ee:
+        a9:09:c5:c9:07:81:b6:d2:bc:bd:13:47:0d:7b:76:f6:8a:c4:
+        76:24:f8:4c:4e:26:fc:d8:c0:1f:3d:40:19:43:8e:41:ab:99:
+        3a:99:9b:24:7c:ae:78:f3:df:2f:a2:ed:8f:27:0a:0a:0b:04:
+        bf:25:74:88:87:96:c8:68:d5:bc:5b:a0:ef:14:aa:53:6e:c4:
+        a3:e3
 -----BEGIN CERTIFICATE-----
-MIIDkTCCAvqgAwIBAgIBAjANBgkqhkiG9w0BAQQFADCBiDELMAkGA1UEBhMCU0Ux
-EDAOBgNVBAcTB1VwcHNhbGExETAPBgNVBAoTCE15U1FMIEFCMSEwHwYDVQQDExhB
-YnN0cmFjdCBNeVNRTCBEZXZlbG9wZXIxMTAvBgkqhkiG9w0BCQEWImFic3RyYWN0
-Lm15c3FsLmRldmVsb3BlckBteXNxbC5jb20wHhcNMDMwOTEyMTYyMjA2WhcNMTMw
-OTA5MTYyMjA2WjB8MQswCQYDVQQGEwJTRTEQMA4GA1UEBxMHVXBwc2FsYTERMA8G
-A1UEChMITXlTUUwgQUIxFTATBgNVBAMTDE15U1FMIFNlcnZlcjExMC8GCSqGSIb3
-DQEJARYiYWJzdHJhY3QubXlzcWwuZGV2ZWxvcGVyQG15c3FsLmNvbTCBnzANBgkq
-hkiG9w0BAQEFAAOBjQAwgYkCgYEA6YZ6VYSITL6k+JJzMBJJC3qFhzk0OQ19C40Y
-wheVE1LSP1UQV8g/WvWy+ovQZ0nMqoL8n84AtHPzNtI608KwDhTD1LIhdKHwMYFg
-h5hzXBDBsRpN8fOwmD/w15ebK/3VIXmyL+tkFcmbnfyeLdT4BFvqqXVLQsM9Dk0q
-qLjKmY0CAwEAAaOCARQwggEQMAkGA1UdEwQCMAAwLAYJYIZIAYb4QgENBB8WHU9w
-ZW5TU0wgR2VuZXJhdGVkIENlcnRpZmljYXRlMB0GA1UdDgQWBBRu5Jtqxerk5sfv
-1x7IY0VgKxvU1DCBtQYDVR0jBIGtMIGqgBSImGXZ8/KLAx1mYGEj+q1zbdNokqGB
-jqSBizCBiDELMAkGA1UEBhMCU0UxEDAOBgNVBAcTB1VwcHNhbGExETAPBgNVBAoT
-CE15U1FMIEFCMSEwHwYDVQQDExhBYnN0cmFjdCBNeVNRTCBEZXZlbG9wZXIxMTAv
-BgkqhkiG9w0BCQEWImFic3RyYWN0Lm15c3FsLmRldmVsb3BlckBteXNxbC5jb22C
-AQAwDQYJKoZIhvcNAQEEBQADgYEAMXdpub2rKfP8WgkWb11C6roBVWnjdc+40be5
-v9pjhYxIkgZgdpfgAHhLrdqrapBtiwOosekJeOEpmFYSYGtC/uinxPjWFQfoK8LY
-iuUbLlEIm1bjs3pMPuW+Sk34ZXuoIeDK/our1+zyLffQv9fFIxwI2KpXx/NfujM/
-eNH0jl4=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==
 -----END CERTIFICATE-----
--- a/client/client_priv.h
+++ b/client/client_priv.h
@ -51,5 +51,5 @@ enum options_client
 #endif
  OPT_TRIGGERS,
  OPT_IGNORE_TABLE,OPT_INSERT_IGNORE,OPT_SHOW_WARNINGS,OPT_DROP_DATABASE,
-  OPT_TZ_UTC, OPT_AUTO_CLOSE
+  OPT_TZ_UTC, OPT_AUTO_CLOSE, OPT_SSL_VERIFY_SERVER_CERT
 };
--- a/client/mysql.cc
+++ b/client/mysql.cc
@ -3123,6 +3123,8 @@ sql_real_connect(char *host,char *database,char *user,char *password,
  if (opt_use_ssl)
    mysql_ssl_set(&mysql, opt_ssl_key, opt_ssl_cert, opt_ssl_ca,
 		  opt_ssl_capath, opt_ssl_cipher);
+  mysql_options(&mysql,MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
+                (char*)&opt_ssl_verify_server_cert);
 #endif
  if (opt_protocol)
    mysql_options(&mysql,MYSQL_OPT_PROTOCOL,(char*)&opt_protocol);
--- a/client/mysqladmin.cc
+++ b/client/mysqladmin.cc
@ -340,6 +340,8 @@ int main(int argc,char *argv[])
  if (opt_use_ssl)
    mysql_ssl_set(&mysql, opt_ssl_key, opt_ssl_cert, opt_ssl_ca,
 		  opt_ssl_capath, opt_ssl_cipher);
+  mysql_options(&mysql,MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
+                (char*)&opt_ssl_verify_server_cert);
 #endif
  if (opt_protocol)
    mysql_options(&mysql,MYSQL_OPT_PROTOCOL,(char*)&opt_protocol);
--- a/client/mysqldump.c
+++ b/client/mysqldump.c
@ -905,6 +905,8 @@ static int dbConnect(char *host, char *user,char *passwd)
  if (opt_use_ssl)
    mysql_ssl_set(&mysql_connection, opt_ssl_key, opt_ssl_cert, opt_ssl_ca,
 		  opt_ssl_capath, opt_ssl_cipher);
+  mysql_options(&mysql_connection,MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
+                (char*)&opt_ssl_verify_server_cert);
 #endif
  if (opt_protocol)
    mysql_options(&mysql_connection,MYSQL_OPT_PROTOCOL,(char*)&opt_protocol);
--- a/client/mysqlimport.c
+++ b/client/mysqlimport.c
@ -384,6 +384,8 @@ static MYSQL *db_connect(char *host, char *database, char *user, char *passwd)
  if (opt_use_ssl)
    mysql_ssl_set(&mysql_connection, opt_ssl_key, opt_ssl_cert, opt_ssl_ca,
 		  opt_ssl_capath, opt_ssl_cipher);
+  mysql_options(&mysql_connection,MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
+                (char*)&opt_ssl_verify_server_cert);
 #endif
  if (opt_protocol)
    mysql_options(&mysql_connection,MYSQL_OPT_PROTOCOL,(char*)&opt_protocol);
--- a/client/mysqlshow.c
+++ b/client/mysqlshow.c
@ -109,6 +109,8 @@ int main(int argc, char **argv)
  if (opt_use_ssl)
    mysql_ssl_set(&mysql, opt_ssl_key, opt_ssl_cert, opt_ssl_ca,
 		  opt_ssl_capath, opt_ssl_cipher);
+  mysql_options(&mysql,MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
+                (char*)&opt_ssl_verify_server_cert);
 #endif
  if (opt_protocol)
    mysql_options(&mysql,MYSQL_OPT_PROTOCOL,(char*)&opt_protocol);
--- a/client/mysqltest.c
+++ b/client/mysqltest.c
@ -108,7 +108,7 @@ enum {OPT_MANAGER_USER=256,OPT_MANAGER_HOST,OPT_MANAGER_PASSWD,
      OPT_MANAGER_PORT,OPT_MANAGER_WAIT_TIMEOUT, OPT_SKIP_SAFEMALLOC,
      OPT_SSL_SSL, OPT_SSL_KEY, OPT_SSL_CERT, OPT_SSL_CA, OPT_SSL_CAPATH,
      OPT_SSL_CIPHER,OPT_PS_PROTOCOL,OPT_SP_PROTOCOL,OPT_CURSOR_PROTOCOL,
-      OPT_VIEW_PROTOCOL};
+      OPT_VIEW_PROTOCOL, OPT_SSL_VERIFY_SERVER_CERT};

 /* ************************************************************************ */
 /*
@ -2378,8 +2378,12 @@ int do_connect(struct st_query *q)

 #ifdef HAVE_OPENSSL
  if (opt_use_ssl || con_ssl)
+  {
    mysql_ssl_set(&next_con->mysql, opt_ssl_key, opt_ssl_cert, opt_ssl_ca,
 		  opt_ssl_capath, opt_ssl_cipher);
+    mysql_options(&next_con->mysql, MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
+                  &opt_ssl_verify_server_cert);
+  }
 #endif
  if (con_sock && !free_con_sock && *con_sock && *con_sock != FN_LIBCHAR)
    con_sock=fn_format(buff, con_sock, TMPDIR, "",0);
@ -4604,9 +4608,14 @@ int main(int argc, char **argv)
  mysql_options(&cur_con->mysql, MYSQL_SET_CHARSET_NAME, charset_name);

 #ifdef HAVE_OPENSSL
+  opt_ssl_verify_server_cert= TRUE; /* Always on in mysqltest */
  if (opt_use_ssl)
+  {
    mysql_ssl_set(&cur_con->mysql, opt_ssl_key, opt_ssl_cert, opt_ssl_ca,
 		  opt_ssl_capath, opt_ssl_cipher);
+    mysql_options(&cur_con->mysql, MYSQL_OPT_SSL_VERIFY_SERVER_CERT,
+                  &opt_ssl_verify_server_cert);
+  }
 #endif

  if (!(cur_con->name = my_strdup("default", MYF(MY_WME))))
--- a/include/mysql.h
+++ b/include/mysql.h
@ -149,7 +149,8 @@ enum mysql_option
  MYSQL_OPT_WRITE_TIMEOUT, MYSQL_OPT_USE_RESULT,
  MYSQL_OPT_USE_REMOTE_CONNECTION, MYSQL_OPT_USE_EMBEDDED_CONNECTION,
  MYSQL_OPT_GUESS_CONNECTION, MYSQL_SET_CLIENT_IP, MYSQL_SECURE_AUTH,
-  MYSQL_REPORT_DATA_TRUNCATION, MYSQL_OPT_RECONNECT
+  MYSQL_REPORT_DATA_TRUNCATION, MYSQL_OPT_RECONNECT,
+  MYSQL_OPT_SSL_VERIFY_SERVER_CERT
 };

 struct st_mysql_options {
@ -164,6 +165,7 @@ struct st_mysql_options {
  char *ssl_ca;					/* PEM CA file */
  char *ssl_capath;				/* PEM directory of CA-s? */
  char *ssl_cipher;				/* cipher to use */
+  my_bool ssl_verify_server_cert;		/* if to verify server cert */
  char *shared_memory_base_name;
  unsigned long max_allowed_packet;
  my_bool use_ssl;				/* if to use SSL or not */
--- a/include/sslopt-longopts.h
+++ b/include/sslopt-longopts.h
@ -37,5 +37,10 @@
  {"ssl-cipher", OPT_SSL_CIPHER, "SSL cipher to use (implies --ssl).",
   (gptr*) &opt_ssl_cipher, (gptr*) &opt_ssl_cipher, 0, GET_STR, REQUIRED_ARG,
   0, 0, 0, 0, 0, 0},
-
+#ifdef MYSQL_CLIENT
+  {"ssl-verify-server-cert", OPT_SSL_VERIFY_SERVER_CERT,
+   "Verify servers \"Common Name\" in it's cert against hostname used when connecting. This option is disabled by default.",
+   (gptr*) &opt_ssl_verify_server_cert, (gptr*) &opt_ssl_verify_server_cert,
+    0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
+#endif
 #endif /* HAVE_OPENSSL */
--- a/include/sslopt-vars.h
+++ b/include/sslopt-vars.h
@ -21,4 +21,7 @@ static char *opt_ssl_cert   = 0;
 static char *opt_ssl_ca     = 0;
 static char *opt_ssl_capath = 0;
 static char *opt_ssl_cipher = 0;
+#ifdef MYSQL_CLIENT
+static my_bool opt_ssl_verify_server_cert= 0;
+#endif
 #endif
--- a/sql-common/client.c
+++ b/sql-common/client.c
@ -1500,6 +1500,7 @@ mysql_ssl_set(MYSQL *mysql __attribute__((unused)) ,
  mysql->options.ssl_ca=     strdup_if_not_null(ca);
  mysql->options.ssl_capath= strdup_if_not_null(capath);
  mysql->options.ssl_cipher= strdup_if_not_null(cipher);
+  mysql->options.ssl_verify_server_cert= FALSE; /* Off by default */
 #endif /* HAVE_OPENSSL */
  DBUG_RETURN(0);
 }
@ -1521,7 +1522,7 @@ mysql_ssl_free(MYSQL *mysql __attribute__((unused)))
  my_free(mysql->options.ssl_cert, MYF(MY_ALLOW_ZERO_PTR));
  my_free(mysql->options.ssl_ca, MYF(MY_ALLOW_ZERO_PTR));
  my_free(mysql->options.ssl_capath, MYF(MY_ALLOW_ZERO_PTR));
-  my_free(mysql->options.ssl_cipher, MYF(MY_ALLOW_ZERO_PTR));  
+  my_free(mysql->options.ssl_cipher, MYF(MY_ALLOW_ZERO_PTR));
  if (ssl_fd)
    SSL_CTX_free(ssl_fd->ssl_context);
  my_free(mysql->connector_fd,MYF(MY_ALLOW_ZERO_PTR));
@ -1534,6 +1535,77 @@ mysql_ssl_free(MYSQL *mysql __attribute__((unused)))
  mysql->connector_fd = 0;
  DBUG_VOID_RETURN;
 }
+
+/*
+  Check the server's (subject) Common Name against the
+  hostname we connected to
+
+  SYNOPSIS
+  ssl_verify_server_cert()
+    vio              pointer to a SSL connected vio
+    server_hostname  name of the server that we connected to
+
+  RETURN VALUES
+   0 Success
+   1 Failed to validate server
+
+ */
+static int ssl_verify_server_cert(Vio *vio, const char* server_hostname)
+{
+  SSL *ssl;
+  X509 *server_cert;
+  char *cp1, *cp2;
+  char buf[256];
+  DBUG_ENTER("ssl_verify_server_cert");
+  DBUG_PRINT("enter", ("server_hostname: %s", server_hostname));
+
+  if (!(ssl= (SSL*)vio->ssl_arg))
+  {
+    DBUG_PRINT("error", ("No SSL pointer found"));
+    DBUG_RETURN(1);
+  }
+
+  if (!server_hostname)
+  {
+    DBUG_PRINT("error", ("No server hostname supplied"));
+    DBUG_RETURN(1);
+  }
+
+  if (!(server_cert= SSL_get_peer_certificate(ssl)))
+  {
+    DBUG_PRINT("error", ("Could not get server certificate"));
+    DBUG_RETURN(1);
+  }
+
+  /*
+    We already know that the certificate exchanged was valid; the SSL library
+    handled that. Now we need to verify that the contents of the certificate
+    are what we expect.
+  */
+
+  X509_NAME_oneline(X509_get_subject_name(server_cert), buf, sizeof(buf));
+  X509_free (server_cert);
+
+  DBUG_PRINT("info", ("hostname in cert: %s", buf));
+  cp1 = strstr(buf, "/CN=");
+  if (cp1)
+  {
+    cp1 += 4; // Skip the "/CN=" that we found
+    // Search for next / which might be the delimiter for email
+    cp2 = strchr(cp1, '/');
+    if (cp2)
+      *cp2 = '\0';
+    DBUG_PRINT("info", ("Server hostname in cert: %s", cp1));
+    if (!strcmp(cp1, server_hostname))
+    {
+      /* Success */
+      DBUG_RETURN(0);
+    }
+  }
+  DBUG_PRINT("error", ("SSL certificate validation failure"));
+  DBUG_RETURN(1);
+}
+
 #endif /* HAVE_OPENSSL */


@ -2049,7 +2121,14 @@ CLI_MYSQL_REAL_CONNECT(MYSQL *mysql,const char *host, const char *user,
    }
    DBUG_PRINT("info", ("IO layer change done!"));

-    /* TODO Verify server cert */
+    /* Verify server cert */
+    if (mysql->options.ssl_verify_server_cert &&
+        ssl_verify_server_cert(mysql->net.vio, mysql->host))
+    {
+      set_mysql_error(mysql, CR_SSL_CONNECTION_ERROR, unknown_sqlstate);
+      goto error;
+    }
+
  }
 #endif /* HAVE_OPENSSL */

@ -2789,6 +2868,9 @@ mysql_options(MYSQL *mysql,enum mysql_option option, const char *arg)
  case MYSQL_OPT_RECONNECT:
    mysql->reconnect= *(my_bool *) arg;
    break;
+  case MYSQL_OPT_SSL_VERIFY_SERVER_CERT:
+    mysql->options.ssl_verify_server_cert= *(my_bool *) arg;
+    break;
  default:
    DBUG_RETURN(1);
  }
--- a/vio/viosslfactories.c
+++ b/vio/viosslfactories.c
@ -290,20 +290,20 @@ new_VioSSLConnectorFd(const char *key_file, const char *cert_file,
                      const char *cipher)
 {
  struct st_VioSSLFd *ssl_fd;
-  int verify= SSL_VERIFY_NONE;
+  int verify= SSL_VERIFY_PEER;
  if (!(ssl_fd= new_VioSSLFd(key_file, cert_file, ca_file,
                             ca_path, cipher, TLSv1_client_method())))
  {
    return 0;
  }
+
  /* Init the the VioSSLFd as a "connector" ie. the client side */

  /*
    The verify_callback function is used to control the behaviour
-    when the SSL_VERIFY_PEER flag is set. Here it is SSL_VERIFY_NONE
-    and thus callback is set to NULL
+    when the SSL_VERIFY_PEER flag is set.
  */
-  SSL_CTX_set_verify(ssl_fd->ssl_context, verify, NULL);
+  SSL_CTX_set_verify(ssl_fd->ssl_context, verify, vio_verify_callback);

  return ssl_fd;
 }