/* * Copyright (c) 1999-2004 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 "config.h" #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 #ifdef HAVE_PAM_PAM_APPL_H # include #else # include #endif #include "sudo.h" #include "sudo_auth.h" /* Only OpenPAM and Linux PAM use const qualifiers. */ #if defined(_OPENPAM) || defined(__LIBPAM_VERSION) # define PAM_CONST const #else # define PAM_CONST #endif #ifndef lint static const char rcsid[] = "$Sudo: pam.c,v 1.43 2004/06/28 14:51:50 millert Exp $"; #endif /* lint */ static int sudo_conv __P((int, PAM_CONST struct pam_message **, struct pam_response **, VOID *)); static char *def_prompt; #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); } if (strcmp(user_tty, "unknown")) (void) pam_set_item(pamh, PAM_TTY, user_tty); 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_ACCT_EXPIRED: log_error(NO_EXIT|NO_MAIL, "%s, %s" "Account or password is expired", "contact your system administrator"); /* FALLTHROUGH */ default: return(AUTH_FAILURE); } case PAM_AUTH_ERR: case PAM_MAXTRIES: 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; { 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*. */ (void) pam_set_item(pamh, PAM_USER, pw->pw_name); (void) pam_set_item(pamh, PAM_RUSER, user_name); /* * 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); 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 *p = def_prompt; char *pass; int n, flags; extern int nil_pw; if ((*response = malloc(num_msg * sizeof(struct pam_response))) == NULL) return(PAM_CONV_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: /* Only override PAM prompt if it matches /^Password: ?/ */ if (strncmp(pm->msg, "Password:", 9) || (pm->msg[9] != '\0' && (pm->msg[9] != ' ' || pm->msg[10] != '\0'))) p = pm->msg; /* Read the password. */ pass = tgetpass(p, def_passwd_timeout * 60, flags); pr->resp = estrdup(pass ? pass : ""); if (*pr->resp == '\0') nil_pw = 1; /* empty password */ else 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: /* 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(PAM_CONV_ERR); } } return(PAM_SUCCESS); }