From 0da41281822ae09674487a921d32a3ba29d76820 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 09:55:15 -0500 Subject: Refactor to pull the long running stuff out of the if statement and into a function --- src/pam-freerdp.c | 69 ++++++++++++++++++++++++++++++++----------------------- 1 file changed, 40 insertions(+), 29 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 7770970..4e43ec4 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -249,6 +249,43 @@ done: return retval; } +static int +session_socket_handler (const char * buffer, int buffer_len, struct passwd * pwdent, int socketfd) +{ + /* Locks to carry over */ + mlock(buffer, buffer_len); + + if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || + setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { + return EXIT_FAILURE; + } + + if (listen(socketfd, 1) < 0) { + return EXIT_FAILURE; + } + + socklen_t connected_addr_size; + int connectfd; + struct sockaddr_un connected_addr; + + connected_addr_size = sizeof(struct sockaddr_un); + connectfd = accept(socketfd, (struct sockaddr *)&connected_addr, &connected_addr_size); + if (connectfd < 0) { + return EXIT_FAILURE; + } + + int writedata; + writedata = write(connectfd, buffer, buffer_len); + + close(connectfd); + + if (writedata == buffer_len) { + return 0; + } + + return EXIT_FAILURE; +} + pid_t session_pid = 0; /* Open Session. Here we need to fork a little process so that we can give the credentials to the session itself so that it can startup the @@ -330,40 +367,14 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv pid_t pid = fork(); if (pid == 0) { - /* Locks to carry over */ - mlock(buffer, buffer_len); + int retval = 0; - if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || - setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { - _exit(EXIT_FAILURE); - } - - if (listen(socketfd, 1) < 0) { - _exit(EXIT_FAILURE); - } - - socklen_t connected_addr_size; - int connectfd; - struct sockaddr_un connected_addr; + retval = session_socket_handler(buffer, buffer_len, pwdent, socketfd); - connected_addr_size = sizeof(struct sockaddr_un); - connectfd = accept(socketfd, (struct sockaddr *)&connected_addr, &connected_addr_size); - if (connectfd < 0) { - _exit(EXIT_FAILURE); - } - - int writedata; - writedata = write(connectfd, buffer, buffer_len); - - close(connectfd); close(socketfd); free(buffer); - if (writedata == buffer_len) { - _exit(0); - } else { - _exit(EXIT_FAILURE); - } + _exit(retval); } else if (pid < 0) { retval = PAM_SYSTEM_ERR; close(socketfd); -- cgit v1.2.3 From c8bbce31973ad6a2c86549f88b7cae4286e1be20 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 10:20:59 -0500 Subject: Move the socket creation into the fork'd function --- src/pam-freerdp.c | 80 +++++++++++++++++++++++++++---------------------------- 1 file changed, 40 insertions(+), 40 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 4e43ec4..1aab5dd 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -250,17 +250,45 @@ done: } static int -session_socket_handler (const char * buffer, int buffer_len, struct passwd * pwdent, int socketfd) +session_socket_handler (const char * buffer, int buffer_len, struct passwd * pwdent) { - /* Locks to carry over */ - mlock(buffer, buffer_len); - if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { return EXIT_FAILURE; } + /* Make our socket and bind it */ + int socketfd; + struct sockaddr_un socket_addr; + + socketfd = socket(AF_UNIX, SOCK_STREAM, 0); + if (socketfd < 0) { + return EXIT_FAILURE; + } + + memset(&socket_addr, 0, sizeof(struct sockaddr_un)); + socket_addr.sun_family = AF_UNIX; + strncpy(socket_addr.sun_path, pwdent->pw_dir, sizeof(socket_addr.sun_path) - 1); + strncpy(socket_addr.sun_path + strlen(pwdent->pw_dir), "/.freerdp-socket", (sizeof(socket_addr.sun_path) - strlen(pwdent->pw_dir)) - 1); + + /* We bind the socket before forking so that we ensure that + there isn't a race condition to get to it. Things will block + otherwise. */ + if (bind(socketfd, (struct sockaddr *)&socket_addr, sizeof(struct sockaddr_un)) < 0) { + close(socketfd); + return EXIT_FAILURE; + } + + /* Set the socket file permissions to be 600 and the user and group + to be the guest user. NOTE: This won't protect on BSD */ + if (chmod(socket_addr.sun_path, S_IRUSR | S_IWUSR) != 0 || + chown(socket_addr.sun_path, pwdent->pw_uid, pwdent->pw_gid) != 0) { + close(socketfd); + return EXIT_FAILURE; + } + if (listen(socketfd, 1) < 0) { + close(socketfd); return EXIT_FAILURE; } @@ -271,12 +299,14 @@ session_socket_handler (const char * buffer, int buffer_len, struct passwd * pwd connected_addr_size = sizeof(struct sockaddr_un); connectfd = accept(socketfd, (struct sockaddr *)&connected_addr, &connected_addr_size); if (connectfd < 0) { + close(socketfd); return EXIT_FAILURE; } int writedata; writedata = write(connectfd, buffer, buffer_len); + close(socketfd); close(connectfd); if (writedata == buffer_len) { @@ -319,39 +349,6 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv goto done; } - /* Make our socket and bind it */ - int socketfd; - struct sockaddr_un socket_addr; - - socketfd = socket(AF_UNIX, SOCK_STREAM, 0); - if (socketfd < 0) { - retval = PAM_SYSTEM_ERR; - goto done; - } - - memset(&socket_addr, 0, sizeof(struct sockaddr_un)); - socket_addr.sun_family = AF_UNIX; - strncpy(socket_addr.sun_path, pwdent->pw_dir, sizeof(socket_addr.sun_path) - 1); - strncpy(socket_addr.sun_path + strlen(pwdent->pw_dir), "/.freerdp-socket", (sizeof(socket_addr.sun_path) - strlen(pwdent->pw_dir)) - 1); - - /* We bind the socket before forking so that we ensure that - there isn't a race condition to get to it. Things will block - otherwise. */ - if (bind(socketfd, (struct sockaddr *)&socket_addr, sizeof(struct sockaddr_un)) < 0) { - close(socketfd); - retval = PAM_SYSTEM_ERR; - goto done; - } - - /* Set the socket file permissions to be 600 and the user and group - to be the guest user. NOTE: This won't protect on BSD */ - if (chmod(socket_addr.sun_path, S_IRUSR | S_IWUSR) != 0 || - chown(socket_addr.sun_path, pwdent->pw_uid, pwdent->pw_gid) != 0) { - close(socketfd); - retval = PAM_SYSTEM_ERR; - goto done; - } - /* Build this up as a buffer so we can just write it and see that very, very clearly */ int buffer_len = 0; @@ -369,15 +366,18 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv if (pid == 0) { int retval = 0; - retval = session_socket_handler(buffer, buffer_len, pwdent, socketfd); + /* Locks to carry over */ + mlock(buffer, buffer_len); - close(socketfd); + retval = session_socket_handler(buffer, buffer_len, pwdent); + + munlock(buffer, buffer_len); + memset(buffer, 0, buffer_len); free(buffer); _exit(retval); } else if (pid < 0) { retval = PAM_SYSTEM_ERR; - close(socketfd); } else { session_pid = pid; } -- cgit v1.2.3 From 7513bc73b72d2478047efac55970470c7ce2cba5 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:02:37 -0500 Subject: Moving buffer allocation into the function --- src/pam-freerdp.c | 43 ++++++++++++++++--------------------------- 1 file changed, 16 insertions(+), 27 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 1aab5dd..a090f02 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -250,15 +250,28 @@ done: } static int -session_socket_handler (const char * buffer, int buffer_len, struct passwd * pwdent) +session_socket_handler (struct passwd * pwdent, const char * ruser, const char * rhost, const char * rdomain, const char * password) { if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { return EXIT_FAILURE; } + /* Build this up as a buffer so we can just write it and see that + very, very clearly */ + int buffer_len = 0; + buffer_len += strlen(ruser) + 1; /* Add one for the space */ + buffer_len += strlen(rhost) + 1; /* Add one for the space */ + buffer_len += strlen(rdomain) + 1; /* Add one for the space */ + buffer_len += strlen(password) + 1; /* Add one for the NULL */ + + char * buffer = malloc(buffer_len); + /* Lock the buffer before writing */ + mlock(buffer, buffer_len); + snprintf(buffer, buffer_len, "%s %s %s %s", ruser, password, rdomain, rhost); + /* Make our socket and bind it */ - int socketfd; + int socketfd = 0; struct sockaddr_un socket_addr; socketfd = socket(AF_UNIX, SOCK_STREAM, 0); @@ -348,32 +361,12 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv retval = PAM_SYSTEM_ERR; goto done; } - - /* Build this up as a buffer so we can just write it and see that - very, very clearly */ - int buffer_len = 0; - buffer_len += strlen(ruser) + 1; /* Add one for the space */ - buffer_len += strlen(rhost) + 1; /* Add one for the space */ - buffer_len += strlen(rdomain) + 1; /* Add one for the space */ - buffer_len += strlen(password) + 1; /* Add one for the NULL */ - - char * buffer = malloc(buffer_len); - /* Lock the buffer before writing */ - mlock(buffer, buffer_len); - snprintf(buffer, buffer_len, "%s %s %s %s", ruser, password, rdomain, rhost); pid_t pid = fork(); if (pid == 0) { int retval = 0; - /* Locks to carry over */ - mlock(buffer, buffer_len); - - retval = session_socket_handler(buffer, buffer_len, pwdent); - - munlock(buffer, buffer_len); - memset(buffer, 0, buffer_len); - free(buffer); + retval = session_socket_handler(pwdent, ruser, rhost, rdomain, password); _exit(retval); } else if (pid < 0) { @@ -382,10 +375,6 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv session_pid = pid; } - memset(buffer, 0, buffer_len); - munlock(buffer, buffer_len); - free(buffer); - done: return retval; } -- cgit v1.2.3 From a2ece3e4d7694e940e0cca31d663233cf623272b Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:11:19 -0500 Subject: Restructure so that clean up is all at the end of the function --- src/pam-freerdp.c | 71 +++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 50 insertions(+), 21 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index a090f02..33105d4 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -252,31 +252,55 @@ done: static int session_socket_handler (struct passwd * pwdent, const char * ruser, const char * rhost, const char * rdomain, const char * password) { + /* Socket stuff */ + int socketfd = 0; + struct sockaddr_un socket_addr; + + /* Connected user */ + socklen_t connected_addr_size; + int connectfd = 0; + struct sockaddr_un connected_addr; + + /* Our buffer */ + char * buffer = NULL; + int buffer_len = 0; + + /* Track write out */ + int writedata = 0; + if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { + /* Don't need to clean up yet */ return EXIT_FAILURE; } /* Build this up as a buffer so we can just write it and see that very, very clearly */ - int buffer_len = 0; buffer_len += strlen(ruser) + 1; /* Add one for the space */ buffer_len += strlen(rhost) + 1; /* Add one for the space */ buffer_len += strlen(rdomain) + 1; /* Add one for the space */ buffer_len += strlen(password) + 1; /* Add one for the NULL */ - char * buffer = malloc(buffer_len); + if (buffer_len < 5) { + /* Don't need to clean up yet */ + return EXIT_FAILURE; + } + + buffer = malloc(buffer_len); + + if (buffer == NULL) { + /* Don't need to clean up yet */ + return EXIT_FAILURE; + } + /* Lock the buffer before writing */ mlock(buffer, buffer_len); snprintf(buffer, buffer_len, "%s %s %s %s", ruser, password, rdomain, rhost); /* Make our socket and bind it */ - int socketfd = 0; - struct sockaddr_un socket_addr; - socketfd = socket(AF_UNIX, SOCK_STREAM, 0); if (socketfd < 0) { - return EXIT_FAILURE; + goto cleanup; } memset(&socket_addr, 0, sizeof(struct sockaddr_un)); @@ -288,40 +312,45 @@ session_socket_handler (struct passwd * pwdent, const char * ruser, const char * there isn't a race condition to get to it. Things will block otherwise. */ if (bind(socketfd, (struct sockaddr *)&socket_addr, sizeof(struct sockaddr_un)) < 0) { - close(socketfd); - return EXIT_FAILURE; + goto cleanup; } /* Set the socket file permissions to be 600 and the user and group to be the guest user. NOTE: This won't protect on BSD */ if (chmod(socket_addr.sun_path, S_IRUSR | S_IWUSR) != 0 || chown(socket_addr.sun_path, pwdent->pw_uid, pwdent->pw_gid) != 0) { - close(socketfd); - return EXIT_FAILURE; + goto cleanup; } if (listen(socketfd, 1) < 0) { - close(socketfd); - return EXIT_FAILURE; + goto cleanup; } - socklen_t connected_addr_size; - int connectfd; - struct sockaddr_un connected_addr; - connected_addr_size = sizeof(struct sockaddr_un); connectfd = accept(socketfd, (struct sockaddr *)&connected_addr, &connected_addr_size); if (connectfd < 0) { - close(socketfd); - return EXIT_FAILURE; + goto cleanup; } - int writedata; writedata = write(connectfd, buffer, buffer_len); - close(socketfd); - close(connectfd); +cleanup: + if (socketfd != 0) { + close(socketfd); + } + if (connectfd != 0) { + close(connectfd); + } + + if (buffer != NULL) { + memset(buffer, 0, buffer_len); + munlock(buffer, buffer_len); + free(buffer); + buffer = NULL; + } + /* This should be only true on the write, so we can use this to check + out as writedata is init to 0 */ if (writedata == buffer_len) { return 0; } -- cgit v1.2.3 From d40d11a475fa08d52dc8a66f34ca2ce28ab39b7e Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:14:46 -0500 Subject: Checking the return for mlock and snprintf --- src/pam-freerdp.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 33105d4..5696bbd 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -264,6 +264,7 @@ session_socket_handler (struct passwd * pwdent, const char * ruser, const char * /* Our buffer */ char * buffer = NULL; int buffer_len = 0; + int buffer_fill = 0; /* Track write out */ int writedata = 0; @@ -294,8 +295,18 @@ session_socket_handler (struct passwd * pwdent, const char * ruser, const char * } /* Lock the buffer before writing */ - mlock(buffer, buffer_len); - snprintf(buffer, buffer_len, "%s %s %s %s", ruser, password, rdomain, rhost); + if (mlock(buffer, buffer_len) != 0) { + /* We can't lock, we go home */ + goto cleanup; + } + + buffer_fill = snprintf(buffer, buffer_len, "%s %s %s %s", ruser, password, rdomain, rhost); + if (buffer_fill > buffer_len) { + /* This really shouldn't happen, but if for some reason we have an + difference between they way that the lengths are calculated we want + to catch that. */ + goto cleanup; + } /* Make our socket and bind it */ socketfd = socket(AF_UNIX, SOCK_STREAM, 0); -- cgit v1.2.3 From 49131cc81474a9bc7f872f948ea148ca8a602e29 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:24:18 -0500 Subject: Setting up a pipe to communicate with the sub process --- src/pam-freerdp.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 5696bbd..9007a52 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -250,7 +250,7 @@ done: } static int -session_socket_handler (struct passwd * pwdent, const char * ruser, const char * rhost, const char * rdomain, const char * password) +session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruser, const char * rhost, const char * rdomain, const char * password) { /* Socket stuff */ int socketfd = 0; @@ -402,16 +402,27 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv goto done; } + int sessionready[2]; + if (pipe(sessionready) != 0) { + retval = PAM_SYSTEM_ERR; + goto done; + } + pid_t pid = fork(); if (pid == 0) { int retval = 0; - retval = session_socket_handler(pwdent, ruser, rhost, rdomain, password); + retval = session_socket_handler(pwdent, sessionready[1], ruser, rhost, rdomain, password); + close(sessionready[1]); _exit(retval); } else if (pid < 0) { + close(sessionready[0]); + close(sessionready[1]); + retval = PAM_SYSTEM_ERR; } else { + close(sessionready[0]); session_pid = pid; } -- cgit v1.2.3 From 63889954b78abbb9396fce05620f61e834e8a2ed Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:34:13 -0500 Subject: Use the pipe to signal when the subprocess has gotten to a point where it can opperate. --- src/pam-freerdp.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 9007a52..89c5d5d 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -33,6 +33,7 @@ #include #define PAM_TYPE_DOMAIN 1234 +#define ALL_GOOD_SIGNAL "Ar, ready to authenticate cap'n" static char * global_domain = NULL; /* FIXME? This is a work around to the fact that PAM seems to be clearing @@ -269,6 +270,9 @@ session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruse /* Track write out */ int writedata = 0; + /* Track ready writing */ + int readywrite = 0; + if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { /* Don't need to clean up yet */ @@ -337,6 +341,11 @@ session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruse goto cleanup; } + readywrite = write(readypipe, ALL_GOOD_SIGNAL, strlen(ALL_GOOD_SIGNAL) + 1); + if (readywrite != strlen(ALL_GOOD_SIGNAL) + 1) { + goto cleanup; + } + connected_addr_size = sizeof(struct sockaddr_un); connectfd = accept(socketfd, (struct sockaddr *)&connected_addr, &connected_addr_size); if (connectfd < 0) { @@ -422,8 +431,18 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv retval = PAM_SYSTEM_ERR; } else { + char readbuffer[strlen(ALL_GOOD_SIGNAL) + 1]; + int readlen = 0; + + readlen = read(sessionready[0], readbuffer, strlen(ALL_GOOD_SIGNAL) + 1); + close(sessionready[0]); - session_pid = pid; + + if (readlen == strlen(ALL_GOOD_SIGNAL) + 1) { + session_pid = pid; + } else { + retval = PAM_SYSTEM_ERR; + } } done: -- cgit v1.2.3 From bda98f787c631e65e347e414b2bb1a3e0c10423a Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:49:06 -0500 Subject: Checking the return value of the mlock --- src/pam-freerdp.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 89c5d5d..0e5c3fa 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -150,8 +150,13 @@ get_item (pam_handle_t * pamh, int type) free(global_password); } global_password = strdup(promptval); - mlock(global_password, strlen(global_password)); - retval = global_password; + if (mlock(global_password, strlen(global_password)) != 0) { + /* Woah, can't lock it. Can't keep it. */ + free(global_password); + global_password = NULL; + } else { + retval = global_password; + } } free(promptval); -- cgit v1.2.3 From 58bca1e60eaccd13b99cfcba93a6ad7ab6d93f75 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:53:42 -0500 Subject: Locking memory if we expect the prompt to be returning a password --- src/pam-freerdp.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 0e5c3fa..43b16d5 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -110,6 +110,18 @@ get_item (pam_handle_t * pamh, int type) char * promptval = responses->resp; free(responses); + /* If we didn't get anything, just move on */ + if (promptval == NULL) { + return NULL; + } + + if (type == PAM_AUTHTOK) { + if (mlock(promptval, strlen(promptval) + 1) != 0) { + free(promptval); + return NULL; + } + } + if (type == PAM_RHOST) { char * subloc = strstr(promptval, "://"); if (subloc != NULL) { @@ -146,11 +158,11 @@ get_item (pam_handle_t * pamh, int type) /* We also save the password globally if we've got one */ if (global_password != NULL) { memset(global_password, 0, strlen(global_password)); - munlock(global_password, strlen(global_password)); + munlock(global_password, strlen(global_password) + 1); free(global_password); } global_password = strdup(promptval); - if (mlock(global_password, strlen(global_password)) != 0) { + if (mlock(global_password, strlen(global_password) + 1) != 0) { /* Woah, can't lock it. Can't keep it. */ free(global_password); global_password = NULL; @@ -159,6 +171,11 @@ get_item (pam_handle_t * pamh, int type) } } + if (type == PAM_AUTHTOK) { + memset(promptval, 0, strlen(promptval) + 1); + munlock(promptval, strlen(promptval) + 1); + } + free(promptval); } -- cgit v1.2.3 From 3058f050cdb8f65f176281a82def12804ae85d05 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:55:41 -0500 Subject: Make sure to clear the environments --- src/pam-freerdp.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 43b16d5..ed83402 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -238,6 +238,10 @@ pam_sm_authenticate (pam_handle_t *pamh, int flags, int argc, const char **argv) _exit(EXIT_FAILURE); } + if (clearenv() != 0) { + _exit(EXIT_FAILURE); + } + setenv("HOME", pwdent->pw_dir, 1); execvp(args[0], args); @@ -301,6 +305,11 @@ session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruse return EXIT_FAILURE; } + if (clearenv() != 0) { + /* Don't need to clean up yet */ + return EXIT_FAILURE; + } + /* Build this up as a buffer so we can just write it and see that very, very clearly */ buffer_len += strlen(ruser) + 1; /* Add one for the space */ -- cgit v1.2.3 From f839484b45f89e62a3e635c35402ebd807e78499 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 11:58:02 -0500 Subject: Clear the groups when dropping privs --- src/pam-freerdp.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index ed83402..90686a9 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -238,6 +239,10 @@ pam_sm_authenticate (pam_handle_t *pamh, int flags, int argc, const char **argv) _exit(EXIT_FAILURE); } + if (setgroups(1, &pwdent->pw_gid) != 0) { + _exit(EXIT_FAILURE); + } + if (clearenv() != 0) { _exit(EXIT_FAILURE); } @@ -305,6 +310,11 @@ session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruse return EXIT_FAILURE; } + if (setgroups(1, &pwdent->pw_gid) != 0) { + /* Don't need to clean up yet */ + return EXIT_FAILURE; + } + if (clearenv() != 0) { /* Don't need to clean up yet */ return EXIT_FAILURE; -- cgit v1.2.3 From d71967fdfecdc1ed309eac4e68b4a72d522d3633 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 12:01:14 -0500 Subject: Make sure to lock the password buffer --- src/freerdp-auth-check.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/freerdp-auth-check.c b/src/freerdp-auth-check.c index d50833b..178db98 100644 --- a/src/freerdp-auth-check.c +++ b/src/freerdp-auth-check.c @@ -60,6 +60,10 @@ main (int argc, char * argv[]) return -1; } + if (mlock(password, sizeof(password)) != 0) { + return -1; + } + freerdp_channels_global_init(); freerdp * instance = freerdp_new(); @@ -88,10 +92,14 @@ main (int argc, char * argv[]) instance->settings->port = strtoul(colonloc, NULL, 10); } + int retval = -1; if (freerdp_connect(instance)) { freerdp_disconnect(instance); - return 0; - } else { - return -1; + retval = 0; } + + memset(password, 0, sizeof(password)); + munlock(password, sizeof(password)); + + return retval; } -- cgit v1.2.3 From 4b95b652e1567fe781be8e91450903169cc45e12 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 12:02:34 -0500 Subject: Dropping the ignoring of the cert --- src/freerdp-auth-check.c | 1 - 1 file changed, 1 deletion(-) (limited to 'src') diff --git a/src/freerdp-auth-check.c b/src/freerdp-auth-check.c index 178db98..e5e9d13 100644 --- a/src/freerdp-auth-check.c +++ b/src/freerdp-auth-check.c @@ -81,7 +81,6 @@ main (int argc, char * argv[]) instance->settings->username = argv[2]; instance->settings->domain = argv[3]; instance->settings->password = password; - instance->settings->ignore_certificate = true; char * colonloc = strstr(argv[1], ":"); if (colonloc != NULL) { -- cgit v1.2.3 From 716fa94e881301ddbc923fbde787d32b70a7243c Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 12:06:11 -0500 Subject: Make sure to change the working directory for the subprocesses to the guest user's home directory --- src/pam-freerdp.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 90686a9..f097ae2 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -247,6 +247,10 @@ pam_sm_authenticate (pam_handle_t *pamh, int flags, int argc, const char **argv) _exit(EXIT_FAILURE); } + if (chdir(pwdent->pw_dir) != 0) { + _exit(EXIT_FAILURE); + } + setenv("HOME", pwdent->pw_dir, 1); execvp(args[0], args); @@ -320,6 +324,11 @@ session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruse return EXIT_FAILURE; } + if (chdir(pwdent->pw_dir) != 0) { + /* Don't need to clean up yet */ + return EXIT_FAILURE; + } + /* Build this up as a buffer so we can just write it and see that very, very clearly */ buffer_len += strlen(ruser) + 1; /* Add one for the space */ -- cgit v1.2.3 From 0501a4375073d9e098446cb3b4c1515b08704a23 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 12:16:31 -0500 Subject: Making sure to kill as the user so that if there is PID wrap or something else we won't kill the wrong thing --- src/pam-freerdp.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 51 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index f097ae2..4b97bb8 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -504,12 +504,60 @@ done: PAM_EXTERN int pam_sm_close_session (pam_handle_t *pamh, int flags, int argc, const char **argv) { - if (session_pid != 0) { - kill(session_pid, SIGKILL); + if (session_pid == 0) { + return PAM_IGNORE; + } + + char * username = NULL; + int retval = PAM_SUCCESS; + + GET_ITEM(username, PAM_USER); + + struct passwd * pwdent = getpwnam(username); + if (pwdent == NULL) { + retval = PAM_SYSTEM_ERR; + goto done; + } + + pid_t pid = fork(); + if (pid == 0) { + if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || + setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { + _exit(EXIT_FAILURE); + } + + if (setgroups(1, &pwdent->pw_gid) != 0) { + _exit(EXIT_FAILURE); + } + + if (clearenv() != 0) { + _exit(EXIT_FAILURE); + } + + int killval = kill(session_pid, SIGKILL); session_pid = 0; + + if (killval != 0) { + printf("Unable to kill\n"); + } + + /* NOTE: We're ignoring whether we could kill it or not. It'd be nice to + track that but there are a lot of reason that we could fail there and + it's not a bad thing. Really we're attempting a best effort to clean up + we won't be able to gaurantee it. */ + _exit(EXIT_SUCCESS); + } else if (pid < 0) { + retval = PAM_SYSTEM_ERR; + } else { + int forkret = 0; + + if (waitpid(pid, &forkret, 0) < 0) { + retval = PAM_SYSTEM_ERR; + } } - return PAM_IGNORE; +done: + return retval; } /* LightDM likes to have this function around, but we don't need it as we -- cgit v1.2.3 From 73858946b83ff5fe24aea484af32bb8ed4c1a1c2 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 13:49:41 -0500 Subject: Clear the session_pid after trying to kill it. --- src/pam-freerdp.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 4b97bb8..88286c9 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -556,6 +556,10 @@ pam_sm_close_session (pam_handle_t *pamh, int flags, int argc, const char **argv } } + /* We reset this no matter. If we error'd trying to do it, we don't + want to try again. We'll just return the error for this time. */ + session_pid = 0; + done: return retval; } -- cgit v1.2.3 From 85bd7adb19764abedb6ef072c17a16ebd53a2b1c Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 14:52:01 -0500 Subject: Removing setgroups as it doesn't seem to be working --- src/pam-freerdp.c | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 88286c9..24a55d0 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -239,10 +239,6 @@ pam_sm_authenticate (pam_handle_t *pamh, int flags, int argc, const char **argv) _exit(EXIT_FAILURE); } - if (setgroups(1, &pwdent->pw_gid) != 0) { - _exit(EXIT_FAILURE); - } - if (clearenv() != 0) { _exit(EXIT_FAILURE); } @@ -314,11 +310,6 @@ session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruse return EXIT_FAILURE; } - if (setgroups(1, &pwdent->pw_gid) != 0) { - /* Don't need to clean up yet */ - return EXIT_FAILURE; - } - if (clearenv() != 0) { /* Don't need to clean up yet */ return EXIT_FAILURE; @@ -526,10 +517,6 @@ pam_sm_close_session (pam_handle_t *pamh, int flags, int argc, const char **argv _exit(EXIT_FAILURE); } - if (setgroups(1, &pwdent->pw_gid) != 0) { - _exit(EXIT_FAILURE); - } - if (clearenv() != 0) { _exit(EXIT_FAILURE); } -- cgit v1.2.3 From dbef2c50ce25e1fbb6a517fa1103d953c5c50dd8 Mon Sep 17 00:00:00 2001 From: Ted Gould Date: Thu, 30 Aug 2012 22:35:28 -0500 Subject: Clearing the groups, but handling the EPERM issue with not being root --- src/pam-freerdp.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'src') diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 24a55d0..b271834 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -234,6 +235,12 @@ pam_sm_authenticate (pam_handle_t *pamh, int flags, int argc, const char **argv) _exit(EXIT_FAILURE); } + /* Setting groups, but allowing EPERM as if we're not 100% root + we might not be able to do this */ + if (setgroups(1, &pwdent->pw_gid) != 0 && errno != EPERM) { + _exit(EXIT_FAILURE); + } + if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { _exit(EXIT_FAILURE); @@ -304,6 +311,12 @@ session_socket_handler (struct passwd * pwdent, int readypipe, const char * ruse /* Track ready writing */ int readywrite = 0; + /* Setting groups, but allowing EPERM as if we're not 100% root + we might not be able to do this */ + if (setgroups(1, &pwdent->pw_gid) != 0 && errno != EPERM) { + _exit(EXIT_FAILURE); + } + if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { /* Don't need to clean up yet */ @@ -512,6 +525,12 @@ pam_sm_close_session (pam_handle_t *pamh, int flags, int argc, const char **argv pid_t pid = fork(); if (pid == 0) { + /* Setting groups, but allowing EPERM as if we're not 100% root + we might not be able to do this */ + if (setgroups(1, &pwdent->pw_gid) != 0 && errno != EPERM) { + _exit(EXIT_FAILURE); + } + if (setgid(pwdent->pw_gid) < 0 || setuid(pwdent->pw_uid) < 0 || setegid(pwdent->pw_gid) < 0 || seteuid(pwdent->pw_uid) < 0) { _exit(EXIT_FAILURE); -- cgit v1.2.3