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-rw-r--r--src/external/platform.m412
-rw-r--r--src/responder/common/responder.h4
-rw-r--r--src/responder/common/responder_common.c133
-rw-r--r--src/sss_client/common.c122
4 files changed, 266 insertions, 5 deletions
diff --git a/src/external/platform.m4 b/src/external/platform.m4
index 71b4f2c85..ee0093789 100644
--- a/src/external/platform.m4
+++ b/src/external/platform.m4
@@ -27,3 +27,15 @@ fi
AM_CONDITIONAL([HAVE_FEDORA], [test x"$osname" == xfedora])
AM_CONDITIONAL([HAVE_REDHAT], [test x"$osname" == xredhat])
AM_CONDITIONAL([HAVE_SUSE], [test x"$osname" == xsuse])
+
+AC_CHECK_MEMBERS([struct ucred.pid, struct ucred.uid, struct ucred.gid], , ,
+ [[#define _GNU_SOURCE
+ #include <sys/socket.h>]])
+
+if test x"$ac_cv_member_struct_ucred_pid" = xyes -a \
+ x"$ac_cv_member_struct_ucred_uid" = xyes -a \
+ x"$ac_cv_member_struct_ucred_gid" = xyes ; then
+ AC_DEFINE([HAVE_UCRED], [1], [Define if struct ucred is available])
+else
+ AC_MSG_WARN([struct ucred is not available])
+fi
diff --git a/src/responder/common/responder.h b/src/responder/common/responder.h
index ea6ba5831..6391fcf7c 100644
--- a/src/responder/common/responder.h
+++ b/src/responder/common/responder.h
@@ -101,6 +101,10 @@ struct cli_ctx {
struct cli_request *creq;
struct cli_protocol_version *cli_protocol_version;
int priv;
+ int creds_exchange_done;
+ int client_uid;
+ int client_gid;
+ int client_pid;
};
struct sss_cmd_table {
diff --git a/src/responder/common/responder_common.c b/src/responder/common/responder_common.c
index f524afb93..f4de3a79e 100644
--- a/src/responder/common/responder_common.c
+++ b/src/responder/common/responder_common.c
@@ -19,6 +19,9 @@
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+/* for struct ucred */
+#define _GNU_SOURCE
+
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
@@ -29,7 +32,8 @@
#include <string.h>
#include <sys/time.h>
#include <errno.h>
-#include "popt.h"
+#include <popt.h>
+#include "config.h"
#include "util/util.h"
#include "db/sysdb.h"
#include "confdb/confdb.h"
@@ -144,12 +148,130 @@ static void client_recv(struct tevent_context *ev, struct cli_ctx *cctx)
return;
}
+static void cred_handler(struct cli_ctx *cctx, char action)
+{
+#ifdef HAVE_UCRED
+ int ret;
+ int fd;
+ struct msghdr msg;
+ struct iovec iov;
+ struct cmsghdr *cmsg;
+ struct ucred *creds;
+ char buf[CMSG_SPACE(sizeof(struct ucred))];
+ char dummy='s';
+ int enable=1;
+
+ if (cctx->creds_exchange_done != 0) {
+ DEBUG(1, ("cred_handler called, but creds are already exchanged.\n"));
+ goto failed;
+ }
+
+ fd = cctx->cfd;
+
+ iov.iov_base = &dummy;
+ iov.iov_len = 1;
+
+ memset (&msg, 0, sizeof(msg));
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+
+ msg.msg_control = buf;
+ msg.msg_controllen = sizeof(buf);
+
+ switch (action) {
+ case 'r':
+ ret = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(int));
+ if (ret == -1) {
+ DEBUG(1, ("setsockopt failed: [%d][%s].\n", errno,
+ strerror(errno)));
+ goto failed;
+ }
+
+ ret = recvmsg(fd, &msg, 0);
+ if (ret == -1) {
+ DEBUG(1, ("recvmsg failed.[%d][%s]\n", errno, strerror(errno)));
+ goto failed;
+ }
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+
+ if (cmsg->cmsg_level == SOL_SOCKET &&
+ cmsg->cmsg_type == SCM_CREDENTIALS) {
+ creds = (struct ucred *) CMSG_DATA(cmsg);
+ DEBUG(1, ("creds: [%d][%d][%d]\n",creds->uid, creds->gid,
+ creds->pid));
+ cctx->client_uid = creds->uid;
+ cctx->client_gid = creds->gid;
+ cctx->client_pid = creds->pid;
+ }
+
+ TEVENT_FD_WRITEABLE(cctx->cfde);
+
+ return;
+ break;
+ case 's':
+ cmsg = CMSG_FIRSTHDR(&msg);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_CREDENTIALS;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
+
+ creds = (struct ucred *) CMSG_DATA(cmsg);
+
+ creds->uid = geteuid();
+ creds->gid = getegid();
+ creds->pid = getpid();
+
+ msg.msg_controllen = cmsg->cmsg_len;
+
+ ret = sendmsg(fd, &msg, 0);
+ if (ret == -1) {
+ DEBUG(1, ("sendmsg failed.[%d][%s]\n", errno, strerror(errno)));
+ goto failed;
+ }
+ DEBUG(4, ("Send creds to the client succesfully.\n"));
+ cctx->creds_exchange_done = 1;
+
+ TEVENT_FD_NOT_WRITEABLE(cctx->cfde);
+ return;
+ default:
+ DEBUG(1, ("Unknown action [%c].\n", action));
+ goto failed;
+ }
+
+failed:
+ talloc_free(cctx);
+ return;
+
+#else
+
+ DEBUG(9, ("Credential exchange not available over socket, "
+ "continuing without.\n"));
+ cctx->creds_exchange_done = 1;
+ return;
+
+#endif
+}
+
static void client_fd_handler(struct tevent_context *ev,
struct tevent_fd *fde,
uint16_t flags, void *ptr)
{
struct cli_ctx *cctx = talloc_get_type(ptr, struct cli_ctx);
+ if (cctx->creds_exchange_done == 0) {
+ if (flags & TEVENT_FD_READ) {
+ cred_handler(cctx, 'r');
+ return;
+ }
+ if (flags & TEVENT_FD_WRITE) {
+ cred_handler(cctx, 's');
+ return;
+ }
+ }
+
if (flags & TEVENT_FD_READ) {
client_recv(ev, cctx);
return;
@@ -213,6 +335,10 @@ static void accept_priv_fd_handler(struct tevent_context *ev,
}
cctx->priv = 1;
+ cctx->creds_exchange_done = 0;
+ cctx->client_uid = -1;
+ cctx->client_gid = -1;
+ cctx->client_pid = -1;
cctx->cfde = tevent_add_fd(ev, cctx, cctx->cfd,
TEVENT_FD_READ, client_fd_handler, cctx);
@@ -265,6 +391,11 @@ static void accept_fd_handler(struct tevent_context *ev,
return;
}
+ cctx->creds_exchange_done = 0;
+ cctx->client_uid = -1;
+ cctx->client_gid = -1;
+ cctx->client_pid = -1;
+
cctx->cfde = tevent_add_fd(ev, cctx, cctx->cfd,
TEVENT_FD_READ, client_fd_handler, cctx);
if (!cctx->cfde) {
diff --git a/src/sss_client/common.c b/src/sss_client/common.c
index 6732c24fc..f1c8d1853 100644
--- a/src/sss_client/common.c
+++ b/src/sss_client/common.c
@@ -23,6 +23,9 @@
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+/* for struct ucred */
+#define _GNU_SOURCE
+
#include <nss.h>
#include <security/pam_modules.h>
#include <errno.h>
@@ -36,6 +39,8 @@
#include <string.h>
#include <fcntl.h>
#include <poll.h>
+
+#include "config.h"
#include "sss_cli.h"
/* common functions */
@@ -50,6 +55,104 @@ static void sss_cli_close_socket(void)
}
}
+static int exchange_credentials(void)
+{
+#ifdef HAVE_UCRED
+ int ret;
+ struct msghdr msg;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+ char dummy='a';
+ char buf[CMSG_SPACE(sizeof(struct ucred))];
+ struct ucred *creds;
+ int enable = 1;
+ struct pollfd pfd;
+
+ ret = setsockopt(sss_cli_sd, SOL_SOCKET, SO_PASSCRED, &enable, sizeof(int));
+ if (ret == -1) {
+ return errno;
+ }
+
+ iov.iov_base = &dummy;
+ iov.iov_len = 1;
+
+ memset(&msg, 0, sizeof(msg));
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+
+ msg.msg_control = buf;
+ msg.msg_controllen = sizeof(buf);
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_CREDENTIALS;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
+
+ creds = (struct ucred *) CMSG_DATA(cmsg);
+
+ creds->uid = geteuid();
+ creds->gid = getegid();
+ creds->pid = getpid();
+
+ msg.msg_controllen = cmsg->cmsg_len;
+
+ pfd.fd = sss_cli_sd;
+ pfd.events = POLLOUT;
+ ret = poll(&pfd, 1, SSS_CLI_SOCKET_TIMEOUT);
+ if (ret != 1 || !(pfd.revents & POLLOUT) ) {
+ return errno;
+ }
+
+ ret = sendmsg(sss_cli_sd, &msg, 0);
+ if (ret == -1) {
+ return errno;
+ }
+
+ memset(&msg, 0, sizeof(msg));
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+
+ msg.msg_control = buf;
+ msg.msg_controllen = sizeof(buf);
+
+ pfd.fd = sss_cli_sd;
+ pfd.events = POLLIN;
+ ret = poll(&pfd, 1, SSS_CLI_SOCKET_TIMEOUT);
+
+ if (ret != 1 || !(pfd.revents & POLLIN) ) {
+ return errno;
+ }
+
+ ret = recvmsg(sss_cli_sd, &msg, 0);
+ if (ret == -1) {
+ return errno;
+ }
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+
+ if (msg.msg_controllen != 0 && cmsg->cmsg_level == SOL_SOCKET &&
+ cmsg->cmsg_type == SCM_CREDENTIALS) {
+ creds = (struct ucred *) CMSG_DATA(cmsg);
+ if (creds->uid != 0 || creds->gid!= 0) {
+ return SSS_STATUS_UNAVAIL;
+ }
+ }
+
+ return SSS_STATUS_SUCCESS;
+
+#else
+
+ return SSS_STATUS_SUCCESS;
+
+#endif
+}
+
/* Requests:
*
* byte 0-3: 32bit unsigned with length (the complete packet length: 0 to X)
@@ -599,9 +702,10 @@ static enum sss_status sss_cli_check_socket(int *errnop, const char *socket_name
sss_cli_sd = mysd;
- if (sss_nss_check_version(socket_name) == NSS_STATUS_SUCCESS) {
- return SSS_STATUS_SUCCESS;
- }
+ if (exchange_credentials() == SSS_STATUS_SUCCESS)
+ if (sss_nss_check_version(socket_name) == NSS_STATUS_SUCCESS) {
+ return SSS_STATUS_SUCCESS;
+ }
sss_cli_close_socket();
*errnop = EFAULT;
@@ -653,12 +757,22 @@ int sss_pam_make_request(enum sss_cli_command cmd,
if (ret != 0) return PAM_SERVICE_ERR;
if ( ! (stat_buf.st_uid == 0 &&
stat_buf.st_gid == 0 &&
- (stat_buf.st_mode&(S_IFSOCK|S_IRUSR|S_IWUSR)) == stat_buf.st_mode)) {
+ S_ISSOCK(stat_buf.st_mode) &&
+ (stat_buf.st_mode & ~S_IFMT) == 0600 )) {
return PAM_SERVICE_ERR;
}
ret = sss_cli_check_socket(errnop, SSS_PAM_PRIV_SOCKET_NAME);
} else {
+ ret = stat(SSS_PAM_SOCKET_NAME, &stat_buf);
+ if (ret != 0) return PAM_SERVICE_ERR;
+ if ( ! (stat_buf.st_uid == 0 &&
+ stat_buf.st_gid == 0 &&
+ S_ISSOCK(stat_buf.st_mode) &&
+ (stat_buf.st_mode & ~S_IFMT) == 0666 )) {
+ return PAM_SERVICE_ERR;
+ }
+
ret = sss_cli_check_socket(errnop, SSS_PAM_SOCKET_NAME);
}
if (ret != NSS_STATUS_SUCCESS) {
generated by cgit (git 2.34.1) at 2024-11-09 22:58:25 +0000