/* * Copyright (c) 1999-2005, 2007-2008 Todd C. Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Sponsored in part by the Defense Advanced Research Projects * Agency (DARPA) and Air Force Research Laboratory, Air Force * Materiel Command, USAF, under agreement number F39502-99-1-0512. */ #include #include #include #include #ifdef STDC_HEADERS # include # include #else # ifdef HAVE_STDLIB_H # include # endif #endif /* STDC_HEADERS */ #ifdef HAVE_STRING_H # if defined(HAVE_MEMORY_H) && !defined(STDC_HEADERS) # include # endif # include #else # ifdef HAVE_STRINGS_H # include # endif #endif /* HAVE_STRING_H */ #ifdef HAVE_UNISTD_H # include #endif /* HAVE_UNISTD_H */ #include #include #ifdef HAVE_PAM_PAM_APPL_H # include #else # include #endif #ifdef HAVE_DGETTEXT # include # if defined(__LINUX_PAM__) # define PAM_TEXT_DOMAIN "Linux-PAM" # elif defined(__sun__) # define PAM_TEXT_DOMAIN "SUNW_OST_SYSOSPAM" # endif #endif #include "sudo.h" #include "sudo_auth.h" /* Only OpenPAM and Linux PAM use const qualifiers. */ #if defined(_OPENPAM) || defined(__LIBPAM_VERSION) || defined(__LINUX_PAM__) # define PAM_CONST const #else # define PAM_CONST #endif #ifndef lint __unused static const char rcsid[] = "$Sudo: pam.c,v 1.66 2008/12/09 23:48:19 millert Exp $"; #endif /* lint */ static int sudo_conv __P((int, PAM_CONST struct pam_message **, struct pam_response **, void *)); static char *def_prompt; static int gotintr; #ifndef PAM_DATA_SILENT #define PAM_DATA_SILENT 0 #endif static pam_handle_t *pamh; /* global due to pam_prep_user() */ int pam_init(pw, promptp, auth) struct passwd *pw; char **promptp; sudo_auth *auth; { static struct pam_conv pam_conv; static int pam_status; /* Initial PAM setup */ if (auth != NULL) auth->data = (void *) &pam_status; pam_conv.conv = sudo_conv; pam_status = pam_start("sudo", pw->pw_name, &pam_conv, &pamh); if (pam_status != PAM_SUCCESS) { log_error(USE_ERRNO|NO_EXIT|NO_MAIL, "unable to initialize PAM"); return(AUTH_FATAL); } /* * Some versions of pam_lastlog have a bug that * will cause a crash if PAM_TTY is not set so if * there is no tty, set PAM_TTY to the empty string. */ if (user_ttypath == NULL) (void) pam_set_item(pamh, PAM_TTY, ""); else (void) pam_set_item(pamh, PAM_TTY, user_ttypath); return(AUTH_SUCCESS); } int pam_verify(pw, prompt, auth) struct passwd *pw; char *prompt; sudo_auth *auth; { const char *s; int *pam_status = (int *) auth->data; def_prompt = prompt; /* for sudo_conv */ /* PAM_SILENT prevents the authentication service from generating output. */ *pam_status = pam_authenticate(pamh, PAM_SILENT); switch (*pam_status) { case PAM_SUCCESS: *pam_status = pam_acct_mgmt(pamh, PAM_SILENT); switch (*pam_status) { case PAM_SUCCESS: return(AUTH_SUCCESS); case PAM_AUTH_ERR: log_error(NO_EXIT|NO_MAIL, "pam_acct_mgmt: %d", *pam_status); return(AUTH_FAILURE); case PAM_NEW_AUTHTOK_REQD: log_error(NO_EXIT|NO_MAIL, "%s, %s", "Account or password is expired", "reset your password and try again"); *pam_status = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK); if (*pam_status == PAM_SUCCESS) return(AUTH_SUCCESS); if ((s = pam_strerror(pamh, *pam_status))) log_error(NO_EXIT|NO_MAIL, "pam_chauthtok: %s", s); return(AUTH_FAILURE); case PAM_AUTHTOK_EXPIRED: log_error(NO_EXIT|NO_MAIL, "Password expired, contact your system administrator"); return(AUTH_FATAL); case PAM_ACCT_EXPIRED: log_error(NO_EXIT|NO_MAIL, "%s %s", "Account expired or PAM config lacks an \"account\"", "section for sudo, contact your system administrator"); return(AUTH_FATAL); } /* FALLTHROUGH */ case PAM_AUTH_ERR: if (gotintr) { /* error or ^C from tgetpass() */ return(AUTH_INTR); } case PAM_MAXTRIES: case PAM_PERM_DENIED: return(AUTH_FAILURE); default: if ((s = pam_strerror(pamh, *pam_status))) log_error(NO_EXIT|NO_MAIL, "pam_authenticate: %s", s); return(AUTH_FATAL); } } int pam_cleanup(pw, auth) struct passwd *pw; sudo_auth *auth; { int *pam_status = (int *) auth->data; /* If successful, we can't close the session until pam_prep_user() */ if (auth->status == AUTH_SUCCESS) return(AUTH_SUCCESS); *pam_status = pam_end(pamh, *pam_status | PAM_DATA_SILENT); return(*pam_status == PAM_SUCCESS ? AUTH_SUCCESS : AUTH_FAILURE); } int pam_prep_user(pw) struct passwd *pw; { int eval; if (pamh == NULL) pam_init(pw, NULL, NULL); /* * Set PAM_USER to the user we are changing *to* and * set PAM_RUSER to the user we are coming *from*. * We set PAM_RHOST to avoid a bug in Solaris 7 and below. */ (void) pam_set_item(pamh, PAM_USER, pw->pw_name); (void) pam_set_item(pamh, PAM_RUSER, user_name); (void) pam_set_item(pamh, PAM_RHOST, user_host); /* * Set credentials (may include resource limits, device ownership, etc). * We don't check the return value here because in Linux-PAM 0.75 * it returns the last saved return code, not the return code * for the setcred module. Because we haven't called pam_authenticate(), * this is not set and so pam_setcred() returns PAM_PERM_DENIED. * We can't call pam_acct_mgmt() with Linux-PAM for a similar reason. */ (void) pam_setcred(pamh, PAM_ESTABLISH_CRED); #ifndef NO_PAM_SESSION /* * To fully utilize PAM sessions we would need to keep a * sudo process around until the command exits. However, we * can at least cause pam_limits to be run by opening and then * immediately closing the session. */ if ((eval = pam_open_session(pamh, 0)) != PAM_SUCCESS) { (void) pam_end(pamh, eval | PAM_DATA_SILENT); return(AUTH_FAILURE); } (void) pam_close_session(pamh, 0); #endif if (pam_end(pamh, PAM_SUCCESS | PAM_DATA_SILENT) == PAM_SUCCESS) return(AUTH_SUCCESS); else return(AUTH_FAILURE); } /* * ``Conversation function'' for PAM. * XXX - does not handle PAM_BINARY_PROMPT */ static int sudo_conv(num_msg, msg, response, appdata_ptr) int num_msg; PAM_CONST struct pam_message **msg; struct pam_response **response; void *appdata_ptr; { struct pam_response *pr; PAM_CONST struct pam_message *pm; const char *prompt; char *pass; int n, flags, std_prompt; if ((*response = malloc(num_msg * sizeof(struct pam_response))) == NULL) return(PAM_SYSTEM_ERR); zero_bytes(*response, num_msg * sizeof(struct pam_response)); for (pr = *response, pm = *msg, n = num_msg; n--; pr++, pm++) { flags = tgetpass_flags; switch (pm->msg_style) { case PAM_PROMPT_ECHO_ON: SET(flags, TGP_ECHO); case PAM_PROMPT_ECHO_OFF: prompt = def_prompt; /* Is the sudo prompt standard? (If so, we'l just use PAM's) */ std_prompt = strncmp(def_prompt, "Password:", 9) == 0 && (def_prompt[9] == '\0' || (def_prompt[9] == ' ' && def_prompt[10] == '\0')); /* Only override PAM prompt if it matches /^Password: ?/ */ #if defined(PAM_TEXT_DOMAIN) && defined(HAVE_DGETTEXT) if (!def_passprompt_override && (std_prompt || (strcmp(pm->msg, dgettext(PAM_TEXT_DOMAIN, "Password: ")) && strcmp(pm->msg, dgettext(PAM_TEXT_DOMAIN, "Password:"))))) prompt = pm->msg; #else if (!def_passprompt_override && (std_prompt || strncmp(pm->msg, "Password:", 9) || (pm->msg[9] != '\0' && (pm->msg[9] != ' ' || pm->msg[10] != '\0')))) prompt = pm->msg; #endif /* Read the password unless interrupted. */ pass = tgetpass(prompt, def_passwd_timeout * 60, flags); if (pass == NULL) { /* We got ^C instead of a password; abort quickly. */ if (errno == EINTR) gotintr = 1; #if defined(__darwin__) || defined(__APPLE__) pass = ""; #else goto err; #endif } pr->resp = estrdup(pass); zero_bytes(pass, strlen(pass)); break; case PAM_TEXT_INFO: if (pm->msg) (void) puts(pm->msg); break; case PAM_ERROR_MSG: if (pm->msg) { (void) fputs(pm->msg, stderr); (void) fputc('\n', stderr); } break; default: goto err; } } return(PAM_SUCCESS); err: /* Zero and free allocated memory and return an error. */ for (pr = *response, n = num_msg; n--; pr++) { if (pr->resp != NULL) { zero_bytes(pr->resp, strlen(pr->resp)); free(pr->resp); pr->resp = NULL; } } zero_bytes(*response, num_msg * sizeof(struct pam_response)); free(*response); *response = NULL; return(gotintr ? PAM_AUTH_ERR : PAM_CONV_ERR); }