diff options
-rw-r--r-- | src/freerdp-auth-check.c | 15 | ||||
-rw-r--r-- | src/pam-freerdp.c | 334 |
2 files changed, 267 insertions, 82 deletions
diff --git a/src/freerdp-auth-check.c b/src/freerdp-auth-check.c index d50833b..e5e9d13 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(); @@ -77,7 +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) { @@ -88,10 +91,14 @@ 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; } diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 7770970..b271834 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -27,12 +27,15 @@ #include <sys/mman.h> #include <sys/un.h> #include <pwd.h> +#include <grp.h> +#include <errno.h> #include <security/pam_modules.h> #include <security/pam_modutil.h> #include <security/pam_appl.h> #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 @@ -109,6 +112,18 @@ 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) { @@ -145,12 +160,22 @@ 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); - mlock(global_password, strlen(global_password)); - retval = global_password; + if (mlock(global_password, strlen(global_password) + 1) != 0) { + /* Woah, can't lock it. Can't keep it. */ + free(global_password); + global_password = NULL; + } else { + retval = global_password; + } + } + + if (type == PAM_AUTHTOK) { + memset(promptval, 0, strlen(promptval) + 1); + munlock(promptval, strlen(promptval) + 1); } free(promptval); @@ -210,11 +235,25 @@ 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); } + if (clearenv() != 0) { + _exit(EXIT_FAILURE); + } + + if (chdir(pwdent->pw_dir) != 0) { + _exit(EXIT_FAILURE); + } + setenv("HOME", pwdent->pw_dir, 1); execvp(args[0], args); @@ -249,6 +288,150 @@ done: return retval; } +static int +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; + 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; + int buffer_fill = 0; + + /* Track write out */ + int writedata = 0; + + /* 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 */ + return EXIT_FAILURE; + } + + if (clearenv() != 0) { + /* Don't need to clean up yet */ + 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 */ + 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 */ + + 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 */ + 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); + if (socketfd < 0) { + goto cleanup; + } + + 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) { + 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) { + goto cleanup; + } + + if (listen(socketfd, 1) < 0) { + 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) { + goto cleanup; + } + + writedata = write(connectfd, buffer, buffer_len); + +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; + } + + 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 @@ -281,115 +464,110 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv retval = PAM_SYSTEM_ERR; 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) { + int sessionready[2]; + if (pipe(sessionready) != 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); + pid_t pid = fork(); + if (pid == 0) { + int retval = 0; + + 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]); - /* 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; + } else { + char readbuffer[strlen(ALL_GOOD_SIGNAL) + 1]; + int readlen = 0; + + readlen = read(sessionready[0], readbuffer, strlen(ALL_GOOD_SIGNAL) + 1); + + close(sessionready[0]); + + if (readlen == strlen(ALL_GOOD_SIGNAL) + 1) { + session_pid = pid; + } else { + retval = PAM_SYSTEM_ERR; + } } - /* 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; +done: + return retval; +} + +/* Close Session. Make sure our little guy has died so he doesn't become + a zombie and eat things. */ +PAM_EXTERN int +pam_sm_close_session (pam_handle_t *pamh, int flags, int argc, const char **argv) +{ + if (session_pid == 0) { + return PAM_IGNORE; } - /* 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 * username = NULL; + int retval = PAM_SUCCESS; - 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); + 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) { - /* Locks to carry over */ - mlock(buffer, buffer_len); + /* 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); } - if (listen(socketfd, 1) < 0) { + if (clearenv() != 0) { _exit(EXIT_FAILURE); } - socklen_t connected_addr_size; - int connectfd; - struct sockaddr_un connected_addr; + int killval = kill(session_pid, SIGKILL); + session_pid = 0; - connected_addr_size = sizeof(struct sockaddr_un); - connectfd = accept(socketfd, (struct sockaddr *)&connected_addr, &connected_addr_size); - if (connectfd < 0) { - _exit(EXIT_FAILURE); + if (killval != 0) { + printf("Unable to kill\n"); } - int writedata; - writedata = write(connectfd, buffer, buffer_len); - - close(connectfd); - close(socketfd); - free(buffer); - - if (writedata == buffer_len) { - _exit(0); - } else { - _exit(EXIT_FAILURE); - } + /* 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; - close(socketfd); } else { - session_pid = pid; + int forkret = 0; + + if (waitpid(pid, &forkret, 0) < 0) { + retval = PAM_SYSTEM_ERR; + } } - memset(buffer, 0, buffer_len); - munlock(buffer, buffer_len); - free(buffer); + /* 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; -} - -/* Close Session. Make sure our little guy has died so he doesn't become - a zombie and eat things. */ -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); - session_pid = 0; - } - - return PAM_IGNORE; + return retval; } /* LightDM likes to have this function around, but we don't need it as we |