MDEV-31855 validate ssl certificates using client password

if the client enabled --ssl-verify-server-cert, then
the server certificate is verified as follows:

* if --ssl-ca or --ssl-capath were specified, the cert must have
  a proper signature by the specified CA (or CA in the path)
  and the cert's hostname must match the server's hostname.
  If the cert isn't signed or a hostname is wrong - the
  connection is aborted.

* if MARIADB_OPT_TLS_PEER_FP was used and the fingerprint matches,
  the connection is allowed, if it doesn't match - aborted.

* If the connection uses unix socket or named pipes - it's allowed.
  (consistent with server's --require-secure-transport behavior)

otherwise the cert is still in doubt, we don't know if we can trust
it or there's an active MitM in progress.

* If the user has provided no password or the server requested an
  authentication plugin that sends the password in cleartext -
  the connection is aborted.

* Perform the authentication. If the server accepts the password,
  it'll send SHA2(scramble || password hash || cert fingerprint)
  with the OK packet.

* Verify the SHA2 digest, if it matches - the connection is allowed,
  otherwise it's aborted.

debian/libmariadb-dev.install

@@ -20,7 +20,6 @@ usr/include/mariadb/mysql.h
 usr/include/mariadb/mysql/
 usr/include/mariadb/mysql/client_plugin.h
 usr/include/mariadb/mysql/plugin_auth.h
-usr/include/mariadb/mysql/plugin_auth_common.h
 usr/include/mariadb/mysql_com.h
 usr/include/mariadb/mysql_version.h
 usr/include/mariadb/mysqld_error.h

include/sslopt-longopts.h

@@ -53,8 +53,7 @@
 
 #ifdef MYSQL_CLIENT
   {"ssl-verify-server-cert", OPT_SSL_VERIFY_SERVER_CERT,
-   "Verify server's \"Common Name\" in its cert against hostname used "
-   "when connecting. This option is disabled by default.",
+   "Verify server's certificate to prevent man-in-the-middle attacks",
    &opt_ssl_verify_server_cert, &opt_ssl_verify_server_cert,
    0, GET_BOOL, OPT_ARG, 0, 0, 0, 0, 0, 0},
 #endif

mysql-test/lib/generate-ssl-certs.sh

@@ -27,7 +27,7 @@ openssl rsa -in server-key.pem -out server-key.pem
 # sign the server certificate with CA certificate
 openssl ca -keyfile cakey.pem -days 7300 -batch -cert cacert.pem -policy policy_anything -out server-cert.pem -in demoCA/server-req.pem
 
-# server certificate with different validity period (MDEV-7598)
+# server certificate with different validity period (MDEV-16266)
 openssl req -newkey rsa:4096 -keyout server-new-key.pem -out demoCA/server-new-req.pem -days 7301 -nodes -subj '/CN=server-new/C=FI/ST=Helsinki/L=Helsinki/O=MariaDB'
 openssl rsa -in server-new-key.pem -out server-new-key.pem
 openssl ca -keyfile cakey.pem -days 7301 -batch -cert cacert.pem -policy policy_anything -out server-new-cert.pem -in demoCA/server-new-req.pem

mysql-test/main/mysqldump.result

@@ -6666,7 +6666,7 @@ drop table t1;
 mariadb-dump: --xml can't be used with --tab.
 select @@max_connections into @save_max_connections;
 set global max_connections=10;
-mariadb-dump: Got error: 1040: "Too many connections" when trying to connect
+mariadb-dump: Got error: 2002: "Received error packet before completion of TLS handshake. The authenticity of the following error cannot be verified: 1040 - Too many connections" when trying to connect
 set global max_connections=300;
 mariadb-dump: Too many connections
 set global max_connections=@save_max_connections;

mysql-test/main/ssl_7937.test

@@ -14,15 +14,15 @@ create procedure have_ssl()
 
 --disable_abort_on_error
 --echo mysql --ssl-ca=cacert.pem -e "call test.have_ssl()"
---exec $MYSQL --ssl-ca=$MYSQL_TEST_DIR/std_data/cacert.pem -e "call test.have_ssl()" 2>&1
+--exec $MYSQL --protocol tcp --ssl-ca=$MYSQL_TEST_DIR/std_data/cacert.pem -e "call test.have_ssl()" 2>&1
 --echo mysql --ssl -e "call test.have_ssl()"
---exec $MYSQL --ssl -e "call test.have_ssl()" 2>&1
+--exec $MYSQL --protocol tcp --ssl -e "call test.have_ssl()" 2>&1
 --echo mysql --ssl-ca=cacert.pem --ssl-verify-server-cert -e "call test.have_ssl()"
---exec $MYSQL --ssl-ca=$MYSQL_TEST_DIR/std_data/cacert.pem --ssl-verify-server-cert -e "call test.have_ssl()" 2>&1
+--exec $MYSQL --protocol tcp --ssl-ca=$MYSQL_TEST_DIR/std_data/cacert.pem --ssl-verify-server-cert -e "call test.have_ssl()" 2>&1
 
 --echo mysql --ssl --ssl-verify-server-cert -e "call test.have_ssl()"
 --replace_regex /TLS\/SSL error.*certificate[^\n]*/TLS\/SSL error: Failed to verify the server certificate/
---exec $MYSQL --ssl --ssl-verify-server-cert -e "call test.have_ssl()" 2>&1
+--exec $MYSQL --protocol tcp --ssl --ssl-verify-server-cert -e "call test.have_ssl()" 2>&1
 
 --echo #
 --echo # MDEV-27105 --ssl option set as default for mariadb CLI

mysql-test/main/ssl_autoverify,win.rdiff

@@ -0,0 +1,14 @@
+--- main/ssl_autoverify.reject
++++ main/ssl_autoverify.result
+@@ -18,9 +18,9 @@
+ yes
+ # mysql -uroot --ssl-verify-server-cert -e "select test.have_ssl()"
+ ERROR 2026 (HY000): TLS/SSL error: Failed to verify the server certificate
+-# mysql --protocol socket -uroot --ssl-verify-server-cert -e "select test.have_ssl()"
++# mysql --protocol pipe -uroot --ssl-verify-server-cert -e "select test.have_ssl()"
+ test.have_ssl()
+-yes
++no
+ # mysql -unative -pfoo --ssl-verify-server-cert -e "select test.have_ssl()"
+ test.have_ssl()
+ yes

mysql-test/main/ssl_autoverify.opt

@@ -0,0 +1 @@
+--loose-enable-named-pipe

mysql-test/main/ssl_autoverify.result

@@ -0,0 +1,47 @@
+install soname 'auth_ed25519';
+install plugin three_attempts soname 'dialog_examples';
+create user native@'%' identified via mysql_native_password using password('foo');
+create user ed@'%' identified via ed25519 using password('bar');
+create user nohash@'%' identified via three_attempts using 'onetwothree';
+create user multi@'%' identified via mysql_native_password using password('pw1')
+or ed25519 using password('pw2');
+grant all privileges on test.* to native@'%';
+grant all privileges on test.* to ed@'%';
+grant all privileges on test.* to nohash@'%';
+grant all privileges on test.* to multi@'%';
+create function have_ssl() returns char(3)
+return (select if(variable_value > '','yes','no') as 'have_ssl'
+  from information_schema.session_status
+where variable_name='ssl_cipher');
+# mysql -uroot --disable-ssl-verify-server-cert -e "select test.have_ssl()"
+test.have_ssl()
+yes
+# mysql -uroot --ssl-verify-server-cert -e "select test.have_ssl()"
+ERROR 2026 (HY000): TLS/SSL error: Failed to verify the server certificate
+# mysql --protocol socket -uroot --ssl-verify-server-cert -e "select test.have_ssl()"
+test.have_ssl()
+yes
+# mysql -unative -pfoo --ssl-verify-server-cert -e "select test.have_ssl()"
+test.have_ssl()
+yes
+# mysql -ued -pbar --ssl-verify-server-cert -e "select test.have_ssl()"
+test.have_ssl()
+yes
+# mysql -unohash -ponetwothree --disable-ssl-verify-server-cert -e "select test.have_ssl()"
+test.have_ssl()
+yes
+# mysql -unohash -ponetwothree --ssl-verify-server-cert -e "select test.have_ssl()"
+ERROR 2026 (HY000): TLS/SSL error: Failed to verify the server certificate
+# mysql -umulti -ppw1 --ssl-verify-server-cert -e "select test.have_ssl()"
+test.have_ssl()
+yes
+# mysql -umulti -ppw2 --ssl-verify-server-cert -e "select test.have_ssl()"
+test.have_ssl()
+yes
+drop function have_ssl;
+drop user native@'%';
+drop user ed@'%';
+drop user nohash@'%';
+drop user multi@'%';
+uninstall plugin ed25519;
+uninstall plugin three_attempts;

mysql-test/main/ssl_autoverify.test

@@ -0,0 +1,84 @@
+source include/platform.inc;
+source include/not_embedded.inc;
+if (!$AUTH_ED25519_SO) {
+  skip No auth_ed25519 plugin;
+}
+if (!$DIALOG_EXAMPLES_SO) {
+  skip No dialog_examples plugin;
+}
+
+install soname 'auth_ed25519';
+install plugin three_attempts soname 'dialog_examples';
+
+create user native@'%' identified via mysql_native_password using password('foo');
+create user ed@'%' identified via ed25519 using password('bar');
+create user nohash@'%' identified via three_attempts using 'onetwothree';
+create user multi@'%' identified via mysql_native_password using password('pw1')
+                                  or ed25519 using password('pw2');
+grant all privileges on test.* to native@'%';
+grant all privileges on test.* to ed@'%';
+grant all privileges on test.* to nohash@'%';
+grant all privileges on test.* to multi@'%';
+
+create function have_ssl() returns char(3)
+  return (select if(variable_value > '','yes','no') as 'have_ssl'
+  from information_schema.session_status
+  where variable_name='ssl_cipher');
+
+#
+# root user, no password, so cannot validate cert.
+#
+--echo # mysql -uroot --disable-ssl-verify-server-cert -e "select test.have_ssl()"
+--exec $MYSQL --protocol tcp -uroot --disable-ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+--echo # mysql -uroot --ssl-verify-server-cert -e "select test.have_ssl()"
+--replace_regex /TLS\/SSL error.*certificate[^\n]*/TLS\/SSL error: Failed to verify the server certificate/
+--error 1
+--exec $MYSQL --protocol tcp -uroot --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+#
+# unless using a secure transport, like unix_socket or named pipes
+#
+# note that SSL works over unix_socket, and it doesn't work over named pipes
+# but the connection is allowed either way, as the transport is secure
+#
+let proto=socket;
+if ($MTR_COMBINATION_WIN) {
+  let proto=pipe;
+}
+--echo # mysql --protocol $proto -uroot --ssl-verify-server-cert -e "select test.have_ssl()"
+--exec $MYSQL --protocol $proto -uroot --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+#
+# mysql_native_password with password works fine
+#
+--echo # mysql -unative -pfoo --ssl-verify-server-cert -e "select test.have_ssl()"
+--exec $MYSQL --protocol tcp -unative -pfoo --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+#
+# ed25519 with password works fine
+#
+--echo # mysql -ued -pbar --ssl-verify-server-cert -e "select test.have_ssl()"
+--exec $MYSQL --protocol tcp -ued -pbar --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+#
+# three_attempts uses auth string as is, doesn't hash.
+# so it's not safe over untrusted connection and thus cannot validate cert
+#
+--echo # mysql -unohash -ponetwothree --disable-ssl-verify-server-cert -e "select test.have_ssl()"
+--exec $MYSQL --protocol tcp -unohash -ponetwothree --disable-ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+--echo # mysql -unohash -ponetwothree --ssl-verify-server-cert -e "select test.have_ssl()"
+--replace_regex /TLS\/SSL error.*certificate[^\n]*/TLS\/SSL error: Failed to verify the server certificate/
+--error 1
+--exec $MYSQL --protocol tcp -unohash -ponetwothree --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+#
+# multi-auth case, both client and server must use
+# the same plugin for cert validation
+#
+--echo # mysql -umulti -ppw1 --ssl-verify-server-cert -e "select test.have_ssl()"
+--exec $MYSQL --protocol tcp -umulti -ppw1 --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+--echo # mysql -umulti -ppw2 --ssl-verify-server-cert -e "select test.have_ssl()"
+--exec $MYSQL --protocol tcp -umulti -ppw2 --ssl-verify-server-cert -e "select test.have_ssl()" 2>&1
+
+drop function have_ssl;
+drop user native@'%';
+drop user ed@'%';
+drop user nohash@'%';
+drop user multi@'%';
+uninstall plugin ed25519;
+uninstall plugin three_attempts;

sql/mysqld.cc

@@ -4518,6 +4518,7 @@ struct SSL_ACCEPTOR_STATS
   long verify_depth;
   long zero;
   const char *session_cache_mode;
+  uchar fprint[256/8];
 
   SSL_ACCEPTOR_STATS():
     accept(),accept_good(),cache_size(),verify_mode(),verify_depth(),zero(),
@@ -4527,7 +4528,8 @@ struct SSL_ACCEPTOR_STATS
 
   void init()
   {
-    DBUG_ASSERT(ssl_acceptor_fd !=0 && ssl_acceptor_fd->ssl_context != 0);
+    DBUG_ASSERT(ssl_acceptor_fd !=0);
+    DBUG_ASSERT(ssl_acceptor_fd->ssl_context != 0);
     SSL_CTX *ctx= ssl_acceptor_fd->ssl_context;
     accept= 0;
     accept_good= 0;
@@ -4551,6 +4553,9 @@ struct SSL_ACCEPTOR_STATS
     default:
       session_cache_mode= "Unknown"; break;
     }
+    X509 *cert= SSL_CTX_get0_certificate(ctx);
+    uint fplen= sizeof(fprint);
+    X509_digest(cert, EVP_sha256(), fprint, &fplen);
   }
 };
 
@@ -4562,6 +4567,11 @@ void ssl_acceptor_stats_update(int sslaccept_ret)
     statistic_increment(ssl_acceptor_stats.accept_good,&LOCK_status);
 }
 
+LEX_CUSTRING ssl_acceptor_fingerprint()
+{
+  return { ssl_acceptor_stats.fprint, sizeof(ssl_acceptor_stats.fprint) };
+}
+
 static void init_ssl()
 {
 #if !defined(EMBEDDED_LIBRARY)

sql/mysqld.h

@@ -728,6 +728,7 @@ extern pthread_t signal_thread;
 
 #ifdef HAVE_OPENSSL
 extern struct st_VioSSLFd * ssl_acceptor_fd;
+extern LEX_CUSTRING ssl_acceptor_fingerprint();
 #endif /* HAVE_OPENSSL */
 
 /*

sql/sql_acl.cc

@@ -201,15 +201,11 @@ class ACL_USER_PARAM
 };
 
 
-class ACL_USER :public ACL_USER_BASE,
-                public ACL_USER_PARAM
+class ACL_USER :public ACL_USER_BASE, public ACL_USER_PARAM
 {
 public:
-
   ACL_USER() = default;
-  ACL_USER(THD *thd, const LEX_USER &combo,
-           const Account_options &options,
-           const privilege_t privileges);
+  ACL_USER(THD *, const LEX_USER &, const Account_options &, const privilege_t);
 
   ACL_USER *copy(MEM_ROOT *root)
   {
@@ -14390,6 +14386,29 @@ static bool acl_check_ssl(THD *thd, const ACL_USER *acl_user)
   return 1;
 }
 
+static void make_ssl_info(THD *thd, LEX_CSTRING salt, char *info)
+{
+#ifdef HAVE_OPENSSL
+  uchar digest[256/8];
+  if (!salt.length)
+    return;
+
+  /*
+    mark that it's after-auth mysql->info version 1.
+    meaning, it contains sha2(salt, scramble, sha2_cert_fingerprint)
+    encoded in 64 lowercase letters 'a'..'p', one letter per 4 bits (0..15)
+  */
+  *info++= 1; // Version 1
+
+  DBUG_ASSERT(thd->scramble[SCRAMBLE_LENGTH] == 0);
+
+  LEX_CUSTRING fp= ssl_acceptor_fingerprint();
+  my_sha256_multi(digest, salt.str, salt.length, thd->scramble,
+                  (size_t)SCRAMBLE_LENGTH, fp.str, fp.length, NULL);
+  octet2hex(info, digest, sizeof(digest));
+
+#endif
+}
 
 static int do_auth_once(THD *thd, const LEX_CSTRING *auth_plugin_name,
                         MPVIO_EXT *mpvio)
@@ -14507,6 +14526,7 @@ bool acl_authenticate(THD *thd, uint com_change_user_pkt_len)
 {
   int res= CR_OK;
   MPVIO_EXT mpvio;
+  char ssl_info[256/4 + 2]= {0}; // '\1', SHA256 (1 char per 4 bits), '\0'
   enum  enum_server_command command= com_change_user_pkt_len ? COM_CHANGE_USER
                                                              : COM_CONNECT;
   DBUG_ENTER("acl_authenticate");
@@ -14844,7 +14864,10 @@ bool acl_authenticate(THD *thd, uint com_change_user_pkt_len)
     sctx->external_user= my_strdup(key_memory_MPVIO_EXT_auth_info,
                                    mpvio.auth_info.external_user, MYF(0));
 
-  my_ok(thd);
+  if (initialized && !com_change_user_pkt_len)
+    make_ssl_info(thd, acl_user->auth[mpvio.curr_auth-1].salt, ssl_info);
+
+  my_ok(thd, 0, 0, ssl_info[0] == '\1' ? ssl_info : NULL);
 
   PSI_CALL_set_thread_account
     (thd->main_security_ctx.user, static_cast<uint>(strlen(thd->main_security_ctx.user)),