diff options
| -rw-r--r-- | src/pam-freerdp.c | 119 |
1 files changed, 117 insertions, 2 deletions
diff --git a/src/pam-freerdp.c b/src/pam-freerdp.c index 189c82f..b927672 100644 --- a/src/pam-freerdp.c +++ b/src/pam-freerdp.c @@ -4,6 +4,8 @@ #include <unistd.h> #include <sys/wait.h> #include <sys/types.h> +#include <sys/socket.h> +#include <sys/un.h> #include <pwd.h> #include <security/pam_modules.h> @@ -176,13 +178,121 @@ done: return retval; } +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 xfreerdp viewer for the login */ PAM_EXTERN int -pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char **argv) +pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char ** argv) { - return PAM_IGNORE; + if (session_pid != 0) { + kill(session_pid, SIGKILL); + session_pid = 0; + } + + char * username = NULL; + char * password = NULL; + char * ruser = NULL; + char * rhost = NULL; + char * rdomain = NULL; + int retval = PAM_SUCCESS; + + /* Get all the values, or prompt for them, or return with + an auth error */ + GET_ITEM(username, PAM_USER); + GET_ITEM(ruser, PAM_RUSER); + GET_ITEM(rhost, PAM_RHOST); + GET_ITEM(rdomain, PAM_TYPE_DOMAIN); + GET_ITEM(password, PAM_AUTHTOK); + + struct passwd * pwdent = getpwnam(username); + if (pwdent == NULL) { + 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) { + 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) - 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; + } + + /* 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); + snprintf(buffer, buffer_len, "%s %s %s %s", ruser, password, rdomain, rhost); + + 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 (listen(socketfd, 1) < 0) { + _exit(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) { + _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); + } + } else if (pid < 0) { + retval = PAM_SYSTEM_ERR; + } else { + session_pid = pid; + } + +done: + if (username != NULL) { free(username); } + if (password != NULL) { free(password); } + if (ruser != NULL) { free(ruser); } + if (rhost != NULL) { free(rhost); } + if (rdomain != NULL) { free(rdomain); } + + return retval; } /* Close Session. Make sure our little guy has died so he doesn't become @@ -190,6 +300,11 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char **argv) 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; } |