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author | Steve Langasek <steve.langasek@ubuntu.com> | 2019-01-03 17:05:01 -0800 |
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committer | Steve Langasek <steve.langasek@ubuntu.com> | 2019-01-03 17:27:13 -0800 |
commit | 419bd504587ec2bfc9085fe56e7a53433fd1eae6 (patch) | |
tree | d516c2ccae28dbd020cb69f50162f5d32acd7648 /modules/pam_shells/pam_shells.c | |
parent | c68dce23face9f26b651917b418c7f80931fa7b7 (diff) | |
parent | 9c52e721044e7501c3d4567b36d222dc7326224a (diff) | |
download | pam-419bd504587ec2bfc9085fe56e7a53433fd1eae6.tar.gz pam-419bd504587ec2bfc9085fe56e7a53433fd1eae6.tar.bz2 pam-419bd504587ec2bfc9085fe56e7a53433fd1eae6.zip |
merge upstream version 1.0.1
Diffstat (limited to 'modules/pam_shells/pam_shells.c')
-rw-r--r-- | modules/pam_shells/pam_shells.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/modules/pam_shells/pam_shells.c b/modules/pam_shells/pam_shells.c new file mode 100644 index 00000000..89fc297e --- /dev/null +++ b/modules/pam_shells/pam_shells.c @@ -0,0 +1,146 @@ +/* pam_shells module */ + +#define SHELL_FILE "/etc/shells" + +/* + * by Erik Troan <ewt@redhat.com>, Red Hat Software. + * August 5, 1996. + * This code shamelessly ripped from the pam_securetty module. + */ + +#include "config.h" + +#include <pwd.h> +#include <stdarg.h> +#include <string.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <syslog.h> +#include <unistd.h> + +/* + * here, we make a definition for the externally accessible function + * in this file (this definition is required for static a module + * but strongly encouraged generally) it is used to instruct the + * modules include file to define the function prototypes. + */ + +#define PAM_SM_AUTH +#define PAM_SM_ACCOUNT + +#include <security/pam_modules.h> +#include <security/pam_modutil.h> +#include <security/pam_ext.h> + +static int perform_check(pam_handle_t *pamh) +{ + int retval = PAM_AUTH_ERR; + const char *userName; + char *userShell; + char shellFileLine[256]; + struct stat sb; + struct passwd * pw; + FILE * shellFile; + + retval = pam_get_user(pamh, &userName, NULL); + if (retval != PAM_SUCCESS) { + return PAM_SERVICE_ERR; + } + + if (!userName || (userName[0] == '\0')) { + + /* Don't let them use a NULL username... */ + retval = pam_get_user(pamh,&userName,NULL); + if (retval != PAM_SUCCESS) + return PAM_SERVICE_ERR; + + /* It could still be NULL the second time. */ + if (!userName || (userName[0] == '\0')) + return PAM_SERVICE_ERR; + } + + pw = pam_modutil_getpwnam(pamh, userName); + if (!pw) { + return PAM_AUTH_ERR; /* user doesn't exist */ + } + userShell = pw->pw_shell; + + if (stat(SHELL_FILE,&sb)) { + pam_syslog(pamh, LOG_ERR, "Cannot stat %s: %m", SHELL_FILE); + return PAM_AUTH_ERR; /* must have /etc/shells */ + } + + if ((sb.st_mode & S_IWOTH) || !S_ISREG(sb.st_mode)) { + pam_syslog(pamh, LOG_ERR, + "%s is either world writable or not a normal file", + SHELL_FILE); + return PAM_AUTH_ERR; + } + + shellFile = fopen(SHELL_FILE,"r"); + if (shellFile == NULL) { /* Check that we opened it successfully */ + pam_syslog(pamh, LOG_ERR, "Error opening %s: %m", SHELL_FILE); + return PAM_SERVICE_ERR; + } + + retval = 1; + + while(retval && (fgets(shellFileLine, 255, shellFile) != NULL)) { + if (shellFileLine[strlen(shellFileLine) - 1] == '\n') + shellFileLine[strlen(shellFileLine) - 1] = '\0'; + retval = strcmp(shellFileLine, userShell); + } + + fclose(shellFile); + + if (retval) { + return PAM_AUTH_ERR; + } else { + return PAM_SUCCESS; + } +} + +/* --- authentication management functions (only) --- */ + +PAM_EXTERN +int pam_sm_authenticate(pam_handle_t *pamh, int flags UNUSED, + int argc UNUSED, const char **argv UNUSED) +{ + return perform_check(pamh); +} + +PAM_EXTERN +int pam_sm_setcred(pam_handle_t *pamh UNUSED, int flags UNUSED, + int argc UNUSED, const char **argv UNUSED) +{ + return PAM_SUCCESS; +} + +/* --- account management functions (only) --- */ + +PAM_EXTERN +int pam_sm_acct_mgmt(pam_handle_t *pamh, int flags UNUSED, + int argc UNUSED, const char **argv UNUSED) +{ + return perform_check(pamh); +} + +#ifdef PAM_STATIC + +/* static module data */ + +struct pam_module _pam_shells_modstruct = { + "pam_shells", + pam_sm_authenticate, + pam_sm_setcred, + pam_sm_acct_mgmt, + NULL, + NULL, + NULL, +}; + +#endif /* PAM_STATIC */ + +/* end of module definition */ |