revision-id: ed2dcf00fd26e363f34638a841ff17a111b7e324 (mariadb-10.3.6-33-ged2dcf0) parent(s): 4b0cedf82d8d8ba582648dcb4a2620c146862a43 committer: Alexey Botchkov timestamp: 2018-07-01 12:23:54 +0400 message: MDEV-15473 Isolate/sandbox PAM modules, so that they can't crash the server. The new 'safe' version of the PAM plugin. It works using the auth_pam_tool executable. That isolates possible crashes in pam modules and, since we can set the +s bit for the tool, we can normally run modules that read protected information. --- mysql-test/mysql-test-run.pl | 14 ++ mysql-test/suite/plugins/t/pam_init_safe.inc | 14 ++ mysql-test/suite/plugins/t/pam_safe.test | 40 +++++ plugin/auth_pam/CMakeLists.txt | 4 + plugin/auth_pam/auth_pam.c | 145 +---------------- plugin/auth_pam/auth_pam_base.c | 171 +++++++++++++++++++ plugin/auth_pam/auth_pam_safe.c | 235 +++++++++++++++++++++++++++ plugin/auth_pam/auth_pam_tool.c | 132 +++++++++++++++ plugin/auth_pam/auth_pam_tool.h | 75 +++++++++ 9 files changed, 693 insertions(+), 137 deletions(-) diff --git a/mysql-test/mysql-test-run.pl b/mysql-test/mysql-test-run.pl index ddb79b9..dfb0cee 100755 --- a/mysql-test/mysql-test-run.pl +++ b/mysql-test/mysql-test-run.pl @@ -2603,8 +2603,22 @@ sub setup_vardir() { unlink "$plugindir/symlink_test"; } + for (<$bindir/plugin/auth_pam/auth_pam_tool>) + { + mkpath("$plugindir/auth_pam_tool_dir"); + if ($opt_use_copy) + { + copy rel2abs($_), "$plugindir/auth_pam_tool_dir/auth_pam_tool" + } + else + { + symlink rel2abs($_), "$plugindir/auth_pam_tool_dir/auth_pam_tool"; + } + } + for (<$bindir/storage/*/*.so>, <$bindir/plugin/*/*.so>, + <$bindir/plugin/*/auth_pam_tool_dir>, <$bindir/libmariadb/plugins/*/*.so>, <$bindir/libmariadb/*.so>, <$bindir/sql/*.so>) diff --git a/mysql-test/suite/plugins/t/pam_init_safe.inc b/mysql-test/suite/plugins/t/pam_init_safe.inc new file mode 100644 index 0000000..9ca5705 --- /dev/null +++ b/mysql-test/suite/plugins/t/pam_init_safe.inc @@ -0,0 +1,14 @@ + +--source include/not_embedded.inc + +if (!$AUTH_PAM_SAFE_SO) { + skip No pam auth plugin; +} + +eval install plugin pam soname '$AUTH_PAM_SAFE_SO'; +create user test_pam identified via pam using 'mariadb_mtr'; +create user pam_test; +grant proxy on pam_test to test_pam; + +let $plugindir=`SELECT @@global.plugin_dir`; + diff --git a/mysql-test/suite/plugins/t/pam_safe.test b/mysql-test/suite/plugins/t/pam_safe.test new file mode 100644 index 0000000..f8a346e --- /dev/null +++ b/mysql-test/suite/plugins/t/pam_safe.test @@ -0,0 +1,40 @@ + +--source pam_init.inc + +--write_file $MYSQLTEST_VARDIR/tmp/pam_good.txt +not very secret challenge +9225 +select user(), current_user(), database(); +EOF + +--write_file $MYSQLTEST_VARDIR/tmp/pam_bad.txt +not very secret challenge +9224 +select user(), current_user(), database(); +EOF + +--echo # +--echo # athentication is successful, challenge/pin are ok +--echo # note that current_user() differs from user() +--echo # +--exec $MYSQL_TEST -u test_pam --plugin-dir=$plugindir < $MYSQLTEST_VARDIR/tmp/pam_good.txt + +--echo # +--echo # athentication is unsuccessful +--echo # +--error 1 +--exec $MYSQL_TEST -u test_pam --plugin-dir=$plugindir < $MYSQLTEST_VARDIR/tmp/pam_bad.txt + +--echo # +--echo # pam module crashes +--echo # +--error 1 +--exec $MYSQL_TEST -u crash_pam_tool --plugin-dir=$plugindir < $MYSQLTEST_VARDIR/tmp/pam_good.txt + +--remove_file $MYSQLTEST_VARDIR/tmp/pam_good.txt +--remove_file $MYSQLTEST_VARDIR/tmp/pam_bad.txt +drop user test_pam; +drop user pam_test; +let $count_sessions= 1; +--source include/wait_until_count_sessions.inc +uninstall plugin pam; diff --git a/plugin/auth_pam/CMakeLists.txt b/plugin/auth_pam/CMakeLists.txt index 5131752..9c0859c 100644 --- a/plugin/auth_pam/CMakeLists.txt +++ b/plugin/auth_pam/CMakeLists.txt @@ -8,6 +8,10 @@ IF(HAVE_PAM_APPL_H) IF(HAVE_STRNDUP) ADD_DEFINITIONS(-DHAVE_STRNDUP) ENDIF(HAVE_STRNDUP) + ADD_DEFINITIONS(-D_GNU_SOURCE) MYSQL_ADD_PLUGIN(auth_pam auth_pam.c LINK_LIBRARIES pam MODULE_ONLY) + MYSQL_ADD_PLUGIN(auth_pam_safe auth_pam_safe.c LINK_LIBRARIES pam dl MODULE_ONLY) + MYSQL_ADD_EXECUTABLE(auth_pam_tool auth_pam_tool.c DESTINATION ${INSTALL_PLUGINDIR}/auth_pam_tool_dir COMPONENT Server) + TARGET_LINK_LIBRARIES(auth_pam_tool pam) ENDIF(HAVE_PAM_APPL_H) diff --git a/plugin/auth_pam/auth_pam.c b/plugin/auth_pam/auth_pam.c index ffc3d6f..c785ba4 100644 --- a/plugin/auth_pam/auth_pam.c +++ b/plugin/auth_pam/auth_pam.c @@ -1,5 +1,5 @@ /* - Copyright (c) 2011, 2012, Monty Program Ab + Copyright (c) 2018 MariaDB Corporation This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -14,160 +14,31 @@ along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */ -#define _GNU_SOURCE 1 /* for strndup */ - #include <mysql/plugin_auth.h> -#include <stdio.h> -#include <string.h> -#include <security/pam_appl.h> -#include <security/pam_modules.h> struct param { unsigned char buf[10240], *ptr; MYSQL_PLUGIN_VIO *vio; }; -/* It least solaris doesn't have strndup */ - -#ifndef HAVE_STRNDUP -char *strndup(const char *from, size_t length) +static int write_packet(struct param *param, const unsigned char *buf, + int buf_len) { - char *ptr; - size_t max_length= strlen(from); - if (length > max_length) - length= max_length; - if ((ptr= (char*) malloc(length+1)) != 0) - { - memcpy((char*) ptr, (char*) from, length); - ptr[length]=0; - } - return ptr; + return param->vio->write_packet(param->vio, buf, buf_len); } -#endif -#ifndef DBUG_OFF -static char pam_debug = 0; -#define PAM_DEBUG(X) do { if (pam_debug) { fprintf X; } } while(0) -#else -#define PAM_DEBUG(X) /* no-op */ -#endif - -static int conv(int n, const struct pam_message **msg, - struct pam_response **resp, void *data) +static int read_packet(struct param *param, unsigned char **pkt) { - struct param *param = (struct param *)data; - unsigned char *end = param->buf + sizeof(param->buf) - 1; - int i; - - *resp = 0; - - for (i = 0; i < n; i++) - { - /* if there's a message - append it to the buffer */ - if (msg[i]->msg) - { - int len = strlen(msg[i]->msg); - if (len > end - param->ptr) - len = end - param->ptr; - if (len > 0) - { - memcpy(param->ptr, msg[i]->msg, len); - param->ptr+= len; - *(param->ptr)++ = '\n'; - } - } - /* if the message style is *_PROMPT_*, meaning PAM asks a question, - send the accumulated text to the client, read the reply */ - if (msg[i]->msg_style == PAM_PROMPT_ECHO_OFF || - msg[i]->msg_style == PAM_PROMPT_ECHO_ON) - { - int pkt_len; - unsigned char *pkt; - - /* allocate the response array. - freeing it is the responsibility of the caller */ - if (*resp == 0) - { - *resp = calloc(sizeof(struct pam_response), n); - if (*resp == 0) - return PAM_BUF_ERR; - } - - /* dialog plugin interprets the first byte of the packet - as the magic number. - 2 means "read the input with the echo enabled" - 4 means "password-like input, echo disabled" - C'est la vie. */ - param->buf[0] = msg[i]->msg_style == PAM_PROMPT_ECHO_ON ? 2 : 4; - PAM_DEBUG((stderr, "PAM: conv: send(%.*s)\n", (int)(param->ptr - param->buf - 1), param->buf)); - if (param->vio->write_packet(param->vio, param->buf, param->ptr - param->buf - 1)) - return PAM_CONV_ERR; - - pkt_len = param->vio->read_packet(param->vio, &pkt); - if (pkt_len < 0) - { - PAM_DEBUG((stderr, "PAM: conv: recv() ERROR\n")); - return PAM_CONV_ERR; - } - PAM_DEBUG((stderr, "PAM: conv: recv(%.*s)\n", pkt_len, pkt)); - /* allocate and copy the reply to the response array */ - if (!((*resp)[i].resp= strndup((char*) pkt, pkt_len))) - return PAM_CONV_ERR; - param->ptr = param->buf + 1; - } - } - return PAM_SUCCESS; + return param->vio->read_packet(param->vio, pkt); } -#define DO(X) if ((status = (X)) != PAM_SUCCESS) goto end - -#if defined(SOLARIS) || defined(__sun) -typedef void** pam_get_item_3_arg; -#else -typedef const void** pam_get_item_3_arg; -#endif +#include "auth_pam_base.c" static int pam_auth(MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *info) { - pam_handle_t *pamh = NULL; - int status; - const char *new_username= NULL; struct param param; - /* The following is written in such a way to make also solaris happy */ - struct pam_conv pam_start_arg = { &conv, (char*) ¶m }; - - /* - get the service name, as specified in - - CREATE USER ... IDENTIFIED WITH pam AS "service" - */ - const char *service = info->auth_string && info->auth_string[0] - ? info->auth_string : "mysql"; - - param.ptr = param.buf + 1; param.vio = vio; - - PAM_DEBUG((stderr, "PAM: pam_start(%s, %s)\n", service, info->user_name)); - DO( pam_start(service, info->user_name, &pam_start_arg, &pamh) ); - - PAM_DEBUG((stderr, "PAM: pam_authenticate(0)\n")); - DO( pam_authenticate (pamh, 0) ); - - PAM_DEBUG((stderr, "PAM: pam_acct_mgmt(0)\n")); - DO( pam_acct_mgmt(pamh, 0) ); - - PAM_DEBUG((stderr, "PAM: pam_get_item(PAM_USER)\n")); - DO( pam_get_item(pamh, PAM_USER, (pam_get_item_3_arg) &new_username) ); - - if (new_username && strcmp(new_username, info->user_name)) - strncpy(info->authenticated_as, new_username, - sizeof(info->authenticated_as)); - info->authenticated_as[sizeof(info->authenticated_as)-1]= 0; - -end: - pam_end(pamh, status); - PAM_DEBUG((stderr, "PAM: status = %d user = %s\n", status, info->authenticated_as)); - return status == PAM_SUCCESS ? CR_OK : CR_ERROR; + return pam_auth_base(¶m, info); } static struct st_mysql_auth info = diff --git a/plugin/auth_pam/auth_pam_base.c b/plugin/auth_pam/auth_pam_base.c new file mode 100644 index 0000000..30b4e01 --- /dev/null +++ b/plugin/auth_pam/auth_pam_base.c @@ -0,0 +1,171 @@ +/* + Copyright (c) 2018 MariaDB Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */ + +// struct param { + // unsigned char buf[10240], *ptr; + // MYSQL_PLUGIN_VIO *vio; +// }; +//static int write_packet(struct param *param, const unsigned char *buf, + //int buf_len) +//static int read_packet(struct param *param, unsigned char **pkt) + +#include <stdio.h> +#include <string.h> +#include <security/pam_appl.h> +#include <security/pam_modules.h> + +/* It least solaris doesn't have strndup */ + +#ifndef HAVE_STRNDUP +char *strndup(const char *from, size_t length) +{ + char *ptr; + size_t max_length= strlen(from); + if (length > max_length) + length= max_length; + if ((ptr= (char*) malloc(length+1)) != 0) + { + memcpy((char*) ptr, (char*) from, length); + ptr[length]=0; + } + return ptr; +} +#endif + +#ifndef DBUG_OFF +static char pam_debug = 0; +#define PAM_DEBUG(X) do { if (pam_debug) { fprintf X; } } while(0) +#else +#define PAM_DEBUG(X) /* no-op */ +#endif + +static int conv(int n, const struct pam_message **msg, + struct pam_response **resp, void *data) +{ + struct param *param = (struct param *)data; + unsigned char *end = param->buf + sizeof(param->buf) - 1; + int i; + + *resp = 0; + + for (i = 0; i < n; i++) + { + /* if there's a message - append it to the buffer */ + if (msg[i]->msg) + { + int len = strlen(msg[i]->msg); + if (len > end - param->ptr) + len = end - param->ptr; + if (len > 0) + { + memcpy(param->ptr, msg[i]->msg, len); + param->ptr+= len; + *(param->ptr)++ = '\n'; + } + } + /* if the message style is *_PROMPT_*, meaning PAM asks a question, + send the accumulated text to the client, read the reply */ + if (msg[i]->msg_style == PAM_PROMPT_ECHO_OFF || + msg[i]->msg_style == PAM_PROMPT_ECHO_ON) + { + int pkt_len; + unsigned char *pkt; + + /* allocate the response array. + freeing it is the responsibility of the caller */ + if (*resp == 0) + { + *resp = calloc(sizeof(struct pam_response), n); + if (*resp == 0) + return PAM_BUF_ERR; + } + + /* dialog plugin interprets the first byte of the packet + as the magic number. + 2 means "read the input with the echo enabled" + 4 means "password-like input, echo disabled" + C'est la vie. */ + param->buf[0] = msg[i]->msg_style == PAM_PROMPT_ECHO_ON ? 2 : 4; + PAM_DEBUG((stderr, "PAM: conv: send(%.*s)\n", + (int)(param->ptr - param->buf - 1), param->buf)); + if (write_packet(param, param->buf, param->ptr - param->buf - 1)) + return PAM_CONV_ERR; + + pkt_len = read_packet(param, &pkt); + if (pkt_len < 0) + { + PAM_DEBUG((stderr, "PAM: conv: recv() ERROR\n")); + return PAM_CONV_ERR; + } + PAM_DEBUG((stderr, "PAM: conv: recv(%.*s)\n", pkt_len, pkt)); + /* allocate and copy the reply to the response array */ + if (!((*resp)[i].resp= strndup((char*) pkt, pkt_len))) + return PAM_CONV_ERR; + param->ptr = param->buf + 1; + } + } + return PAM_SUCCESS; +} + +#define DO(X) if ((status = (X)) != PAM_SUCCESS) goto end + +#if defined(SOLARIS) || defined(__sun) +typedef void** pam_get_item_3_arg; +#else +typedef const void** pam_get_item_3_arg; +#endif + +static int pam_auth_base(struct param *param, MYSQL_SERVER_AUTH_INFO *info) +{ + pam_handle_t *pamh = NULL; + int status; + const char *new_username= NULL; + /* The following is written in such a way to make also solaris happy */ + struct pam_conv pam_start_arg = { &conv, (char*) param }; + + /* + get the service name, as specified in + + CREATE USER ... IDENTIFIED WITH pam AS "service" + */ + const char *service = info->auth_string && info->auth_string[0] + ? info->auth_string : "mysql"; + + param->ptr = param->buf + 1; + + PAM_DEBUG((stderr, "PAM: pam_start(%s, %s)\n", service, info->user_name)); + DO( pam_start(service, info->user_name, &pam_start_arg, &pamh) ); + + PAM_DEBUG((stderr, "PAM: pam_authenticate(0)\n")); + DO( pam_authenticate (pamh, 0) ); + + PAM_DEBUG((stderr, "PAM: pam_acct_mgmt(0)\n")); + DO( pam_acct_mgmt(pamh, 0) ); + + PAM_DEBUG((stderr, "PAM: pam_get_item(PAM_USER)\n")); + DO( pam_get_item(pamh, PAM_USER, (pam_get_item_3_arg) &new_username) ); + + if (new_username && strcmp(new_username, info->user_name)) + strncpy(info->authenticated_as, new_username, + sizeof(info->authenticated_as)); + info->authenticated_as[sizeof(info->authenticated_as)-1]= 0; + +end: + pam_end(pamh, status); + PAM_DEBUG((stderr, "PAM: status = %d user = %s\n", status, info->authenticated_as)); + return status == PAM_SUCCESS ? CR_OK : CR_ERROR; +} + diff --git a/plugin/auth_pam/auth_pam_safe.c b/plugin/auth_pam/auth_pam_safe.c new file mode 100644 index 0000000..9dac90d --- /dev/null +++ b/plugin/auth_pam/auth_pam_safe.c @@ -0,0 +1,235 @@ +/* + Copyright (c) 2018 MariaDB Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */ + + +#include <unistd.h> +#include <string.h> +#include <mysql/plugin_auth.h> +#include "auth_pam_tool.h" +#include <my_global.h> + +#ifndef DBUG_OFF +static char pam_debug = 0; +#define PAM_DEBUG(X) do { if (pam_debug) { fprintf X; } } while(0) +#else +#define PAM_DEBUG(X) /* no-op */ +#endif + +static char *opt_plugin_dir; /* To be dynamically linked. */ +static const char *tool_name= "auth_pam_tool_dir/auth_pam_tool"; +static const int tool_name_len= 31; + +static int pam_auth(MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *info) +{ + int p_to_c[2], c_to_p[2]; /* Parent-to-child and child-to-parent pipes. */ + pid_t proc_id; + int result= CR_ERROR; + unsigned char field; + + PAM_DEBUG((stderr, "PAM: opening pipes.\n")); + if (pipe(p_to_c) < 0 || pipe(c_to_p) < 0) + { + /* Error creating pipes. */ + return CR_ERROR; + } + PAM_DEBUG((stderr, "PAM: forking.\n")); + if ((proc_id= fork()) < 0) + { + /* Error forking. */ + close(p_to_c[0]); + close(c_to_p[1]); + goto error_ret; + } + + if (proc_id == 0) + { + /* The 'sandbox' process started. */ + char toolpath[FN_REFLEN]; + size_t plugin_dir_len; + + PAM_DEBUG((stderr, "PAM: Child process prepares pipes.\n")); + + if (close(p_to_c[1]) < 0 || + close(c_to_p[0]) < 0 || + dup2(p_to_c[0], 0) < 0 || /* Parent's pipe to STDIN. */ + dup2(c_to_p[1], 1) < 0) /* Sandbox's pipe to STDOUT. */ + { + exit(-1); + } + + PAM_DEBUG((stderr, "PAM: check tool directory: %s, %s.\n", + opt_plugin_dir, tool_name)); + plugin_dir_len= strlen(opt_plugin_dir); + if (plugin_dir_len + tool_name_len + 2 > sizeof(toolpath)) + { + /* Tool path too long. */ + exit(-1); + } + + memcpy(toolpath, opt_plugin_dir, plugin_dir_len); + if (plugin_dir_len && toolpath[plugin_dir_len-1] != FN_LIBCHAR) + toolpath[plugin_dir_len++]= FN_LIBCHAR; + memcpy(toolpath+plugin_dir_len, tool_name, tool_name_len+1); + + PAM_DEBUG((stderr, "PAM: execute pam sandbox [%s].\n", toolpath)); + (void) execl(toolpath, toolpath, NULL); + PAM_DEBUG((stderr, "PAM: exec() failed.\n")); + exit(-1); + } + + /* Parent process continues. */ + + PAM_DEBUG((stderr, "PAM: parent continues.\n")); + if (close(p_to_c[0]) < 0 || + close(c_to_p[1]) < 0) + goto error_ret; + + + PAM_DEBUG((stderr, "PAM: parent sends user data [%s], [%s].\n", + info->user_name, info->auth_string)); + +#ifndef DBUG_OFF + field= pam_debug; +#else + field= 0; +#endif + if (write(p_to_c[1], &field, 1) != 1 || + write_string(p_to_c[1], (const uchar *) info->user_name, + info->user_name_length) || + write_string(p_to_c[1], (const uchar *) info->auth_string, + info->auth_string_length)) + goto error_ret; + + for (;;) + { + PAM_DEBUG((stderr, "PAM: listening to the sandbox.\n")); + if (read(c_to_p[0], &field, 1) < 1) + { + PAM_DEBUG((stderr, "PAM: read failed.\n")); + goto error_ret; + } + + if (field == AP_EOF) + { + PAM_DEBUG((stderr, "PAM: auth OK returned.\n")); + break; + } + + switch (field) + { + case AP_AUTHENTICATED_AS: + PAM_DEBUG((stderr, "PAM: reading authenticated_as string.\n")); + if (read_string(c_to_p[0], info->authenticated_as, + sizeof(info->authenticated_as) - 1) < 0) + goto error_ret; + break; + + case AP_CONV: + { + unsigned char buf[10240]; + int buf_len; + unsigned char *pkt; + + PAM_DEBUG((stderr, "PAM: getting CONV string.\n")); + if ((buf_len= read_string(c_to_p[0], (char *) buf, sizeof(buf))) < 0) + goto error_ret; + + PAM_DEBUG((stderr, "PAM: sending CONV string.\n")); + if (vio->write_packet(vio, buf, buf_len)) + goto error_ret; + + PAM_DEBUG((stderr, "PAM: reading CONV answer.\n")); + if ((buf_len= vio->read_packet(vio, &pkt)) < 0) + goto error_ret; + + PAM_DEBUG((stderr, "PAM: answering CONV.\n")); + if (write_string(p_to_c[1], pkt, buf_len)) + goto error_ret; + } + break; + + default: + PAM_DEBUG((stderr, "PAM: unknown sandbox field.\n")); + goto error_ret; + } + } + result= CR_OK; + +error_ret: + close(p_to_c[1]); + close(c_to_p[0]); + + PAM_DEBUG((stderr, "PAM: auth result %d.\n", result)); + return result; +} + +static struct st_mysql_auth info = +{ + MYSQL_AUTHENTICATION_INTERFACE_VERSION, + "dialog", + pam_auth +}; + +static char use_cleartext_plugin; +static MYSQL_SYSVAR_BOOL(use_cleartext_plugin, use_cleartext_plugin, + PLUGIN_VAR_NOCMDARG | PLUGIN_VAR_READONLY, + "Use mysql_cleartext_plugin on the client side instead of the dialog " + "plugin. This may be needed for compatibility reasons, but it only " + "supports simple PAM policies that don't require anything besides " + "a password", NULL, NULL, 0); + +#ifndef DBUG_OFF +static MYSQL_SYSVAR_BOOL(debug, pam_debug, PLUGIN_VAR_OPCMDARG, + "Log all PAM activity", NULL, NULL, 0); +#endif + + +static struct st_mysql_sys_var* vars[] = { + MYSQL_SYSVAR(use_cleartext_plugin), +#ifndef DBUG_OFF + MYSQL_SYSVAR(debug), +#endif + NULL +}; + + +static int init(void *p __attribute__((unused))) +{ + if (use_cleartext_plugin) + info.client_auth_plugin= "mysql_clear_password"; + if (!(opt_plugin_dir= dlsym(RTLD_DEFAULT, "opt_plugin_dir"))) + return 1; + + return 0; +} + +maria_declare_plugin(pam) +{ + MYSQL_AUTHENTICATION_PLUGIN, + &info, + "pam", + "MariaDB Corp", + "PAM based authentication (safe)", + PLUGIN_LICENSE_GPL, + init, + NULL, + 0x0100, + NULL, + vars, + "1.0", + MariaDB_PLUGIN_MATURITY_BETA +} +maria_declare_plugin_end; diff --git a/plugin/auth_pam/auth_pam_tool.c b/plugin/auth_pam/auth_pam_tool.c new file mode 100644 index 0000000..5f19d29 --- /dev/null +++ b/plugin/auth_pam/auth_pam_tool.c @@ -0,0 +1,132 @@ +/* + Copyright (c) 2018 MariaDB Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */ + +#include <stdlib.h> +#include <unistd.h> +#include <mysql/plugin_auth_common.h> + +struct param { + unsigned char buf[10240], *ptr; +}; + + +#include "auth_pam_tool.h" + + +static int write_packet(struct param *param __attribute__((unused)), + const unsigned char *buf, int buf_len) +{ + unsigned char b= AP_CONV; + return write(1, &b, 1) < 1 || + write_string(1, buf, buf_len); +} + + +static int read_packet(struct param *param, unsigned char **pkt) +{ + *pkt= (unsigned char *) param->buf; + return read_string(0, (char *) param->buf, (int) sizeof(param->buf)) - 1; +} + + +typedef struct st_mysql_server_auth_info +{ + /** + User name as sent by the client and shown in USER(). + NULL if the client packet with the user name was not received yet. + */ + char *user_name; + + /** + A corresponding column value from the mysql.user table for the + matching account name + */ + char *auth_string; + + /** + Matching account name as found in the mysql.user table. + A plugin can override it with another name that will be + used by MySQL for authorization, and shown in CURRENT_USER() + */ + char authenticated_as[MYSQL_USERNAME_LENGTH+1]; +} MYSQL_SERVER_AUTH_INFO; + + +#include "auth_pam_base.c" + + +int main(int argc, char **argv) +{ + struct param param; + MYSQL_SERVER_AUTH_INFO info; + unsigned char field; + int res; + char a_buf[MYSQL_USERNAME_LENGTH + 1 + 1024]; + + if (read(0, &field, 1) < 1) + return -1; +#ifndef DBUG_OFF + pam_debug= field; +#endif + + PAM_DEBUG((stderr, "PAM: sandbox started [%s].\n", argv[0])); + + info.user_name= a_buf; + if ((res= read_string(0, info.user_name, sizeof(a_buf))) < 0) + return -1; + PAM_DEBUG((stderr, "PAM: sandbox username [%s].\n", info.user_name)); + +#ifndef DBUG_OFF + /* Produce the crash for testing purposes. */ + if ((res == 14) && + memcmp(info.user_name, "crash_pam_tool", 14) == 0) + { + info.user_name= 0; + memcpy(info.user_name, a_buf, sizeof(a_buf)); + return -1; + } +#endif + + info.auth_string= info.user_name + res + 1; + if (read_string(0, info.auth_string, sizeof(a_buf) - 1 - res) < 0) + return -1; + + PAM_DEBUG((stderr, "PAM: sandbox auth string [%s].\n", info.auth_string)); + + if ((res= pam_auth_base(¶m, &info)) != CR_OK) + { + PAM_DEBUG((stderr, "PAM: auth failed, sandbox closed.\n")); + return -1; + } + + if (info.authenticated_as[0]) + { + PAM_DEBUG((stderr, "PAM: send authenticated_as field.\n")); + field= AP_AUTHENTICATED_AS; + if (write(1, &field, 1) < 1 || + write_string(1, (unsigned char *) info.authenticated_as, + strlen(info.authenticated_as))) + return -1; + } + + PAM_DEBUG((stderr, "PAM: send OK result.\n")); + field= AP_EOF; + if (write(1, &field, 1) != 1) + return -1; + + PAM_DEBUG((stderr, "PAM: sandbox closed.\n")); + return 0; +} diff --git a/plugin/auth_pam/auth_pam_tool.h b/plugin/auth_pam/auth_pam_tool.h new file mode 100644 index 0000000..688ff69 --- /dev/null +++ b/plugin/auth_pam/auth_pam_tool.h @@ -0,0 +1,75 @@ +/* + Copyright (c) 2018 MariaDB Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */ + +#define AP_USER 'U' +#define AP_AUTHENTICATED_AS 'A' +#define AP_CONV 'C' +#define AP_EOF 'E' + + +static int read_length(int file) +{ + unsigned char hdr[2]; + + if (read(file, hdr, 2) < 2) + return -1; + + return (((int) hdr[0]) << 8) + (int) hdr[1]; +} + + +static void store_length(int len, unsigned char *p_len) +{ + p_len[0]= (unsigned char) ((len >> 8) & 0xFF); + p_len[1]= (unsigned char) (len & 0xFF); +} + + +/* + Returns the length of the string read, + or -1 on error. +*/ + +static int read_string(int file, char *s, int s_size) +{ + int len; + + len= read_length(file); + + if (len < 0 || len > s_size-1 || + read(file, s, len) < len) + return -1; + + s[len]= 0; + + return len; +} + + +/* + Returns 0 on success. +*/ + +static int write_string(int file, const unsigned char *s, int s_len) +{ + unsigned char hdr[2]; + store_length(s_len, hdr); + return write(file, hdr, 2) < 2 || + write(file, s, s_len) < s_len; +} + + +#define MAX_PAM_SERVICE_NAME 1024