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-rw-r--r--plugins/sudoers/auth/pam.c765
1 files changed, 765 insertions, 0 deletions
diff --git a/plugins/sudoers/auth/pam.c b/plugins/sudoers/auth/pam.c
new file mode 100644
index 0000000..6310364
--- /dev/null
+++ b/plugins/sudoers/auth/pam.c
@@ -0,0 +1,765 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 1999-2005, 2007-2020 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * 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.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#ifdef HAVE_PAM
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <errno.h>
+
+#ifdef HAVE_PAM_PAM_APPL_H
+# include <pam/pam_appl.h>
+#else
+# include <security/pam_appl.h>
+#endif
+
+#ifdef __hpux
+# include <nl_types.h>
+#endif
+
+#ifdef HAVE_LIBINTL_H
+# if defined(__LINUX_PAM__)
+# define PAM_TEXT_DOMAIN "Linux-PAM"
+# elif defined(__sun__)
+# define PAM_TEXT_DOMAIN "SUNW_OST_SYSOSPAM"
+# endif
+#endif
+
+/* We don't want to translate the strings in the calls to dgt(). */
+#ifdef PAM_TEXT_DOMAIN
+# define dgt(d, t) dgettext(d, t)
+#endif
+
+#include "sudoers.h"
+#include "sudo_auth.h"
+
+/* Only OpenPAM and Linux PAM use const qualifiers. */
+#ifdef PAM_SUN_CODEBASE
+# define PAM_CONST
+#else
+# define PAM_CONST const
+#endif
+
+/* Ambiguity in spec: is it an array of pointers or a pointer to an array? */
+#ifdef PAM_SUN_CODEBASE
+# define PAM_MSG_GET(msg, n) (*(msg) + (n))
+#else
+# define PAM_MSG_GET(msg, n) ((msg)[(n)])
+#endif
+
+#ifndef PAM_DATA_SILENT
+#define PAM_DATA_SILENT 0
+#endif
+
+struct conv_filter {
+ char *msg;
+ size_t msglen;
+};
+
+static int converse(int, PAM_CONST struct pam_message **,
+ struct pam_response **, void *);
+static struct sudo_conv_callback *conv_callback;
+static struct pam_conv pam_conv = { converse, &conv_callback };
+static char *def_prompt = PASSPROMPT;
+static bool getpass_error;
+static pam_handle_t *pamh;
+static struct conv_filter *conv_filter;
+
+static void
+conv_filter_init(void)
+{
+ debug_decl(conv_filter_init, SUDOERS_DEBUG_AUTH);
+
+#ifdef __hpux
+ /*
+ * HP-UX displays last login information as part of either account
+ * management (in trusted mode) or session management (regular mode).
+ * Filter those out in the conversation function unless running a shell.
+ */
+ if (!ISSET(sudo_mode, MODE_SHELL|MODE_LOGIN_SHELL)) {
+ int i, nfilt = 0, maxfilters = 0;
+ struct conv_filter *newfilt;
+ nl_catd catd;
+ char *msg;
+
+ /*
+ * Messages from PAM account management when trusted mode is enabled:
+ * 1 Last successful login for %s: %s
+ * 2 Last successful login for %s: %s on %s
+ * 3 Last unsuccessful login for %s: %s
+ * 4 Last unsuccessful login for %s: %s on %s
+ */
+ if ((catd = catopen("pam_comsec", NL_CAT_LOCALE)) != -1) {
+ maxfilters += 4;
+ newfilt = reallocarray(conv_filter, maxfilters + 1,
+ sizeof(*conv_filter));
+ if (newfilt != NULL) {
+ conv_filter = newfilt;
+ for (i = 1; i < 5; i++) {
+ if ((msg = catgets(catd, 1, i, NULL)) == NULL)
+ break;
+ sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
+ "adding \"%s\" to conversation filter", msg);
+ if ((conv_filter[nfilt].msg = strdup(msg)) == NULL)
+ break;
+ conv_filter[nfilt].msglen = strcspn(msg, "%");
+ nfilt++;
+ }
+ }
+ }
+ /*
+ * Messages from PAM session management when trusted mode is disabled:
+ * 3 Last successful login: %s %s %s %s
+ * 4 Last authentication failure: %s %s %s %s
+ */
+ if ((catd = catopen("pam_hpsec", NL_CAT_LOCALE)) != -1) {
+ maxfilters += 2;
+ newfilt = reallocarray(conv_filter, maxfilters + 1,
+ sizeof(*conv_filter));
+ if (newfilt != NULL) {
+ conv_filter = newfilt;
+ for (i = 3; i < 5; i++) {
+ if ((msg = catgets(catd, 1, i, NULL)) == NULL)
+ break;
+ sudo_debug_printf(SUDO_DEBUG_INFO|SUDO_DEBUG_LINENO,
+ "adding \"%s\" to conversation filter", msg);
+ if ((conv_filter[nfilt].msg = strdup(msg)) == NULL)
+ break;
+ conv_filter[nfilt].msglen = strcspn(msg, "%");
+ nfilt++;
+ }
+ }
+ }
+ if (conv_filter != NULL) {
+ conv_filter[nfilt].msg = NULL;
+ conv_filter[nfilt].msglen = 0;
+ }
+ }
+#endif /* __hpux */
+ debug_return;
+}
+
+/*
+ * Like pam_strerror() but never returns NULL and uses strerror(errno)
+ * for PAM_SYSTEM_ERR.
+ */
+static const char *
+sudo_pam_strerror(pam_handle_t *handle, int errnum)
+{
+ const char *errstr;
+ static char errbuf[32];
+
+ if (errnum == PAM_SYSTEM_ERR)
+ return strerror(errno);
+ if ((errstr = pam_strerror(handle, errnum)) == NULL)
+ (void)snprintf(errbuf, sizeof(errbuf), "PAM error %d", errnum);
+ return errstr;
+}
+
+static int
+sudo_pam_init2(struct passwd *pw, sudo_auth *auth, bool quiet)
+{
+ static int pam_status = PAM_SUCCESS;
+ const char *ttypath = user_ttypath;
+ const char *errstr, *pam_service;
+ int rc;
+ debug_decl(sudo_pam_init, SUDOERS_DEBUG_AUTH);
+
+ /* Stash pointer to last pam status. */
+ auth->data = &pam_status;
+
+#ifdef _AIX
+ if (pamh != NULL) {
+ /* Already initialized (may happen with AIX). */
+ debug_return_int(AUTH_SUCCESS);
+ }
+#endif /* _AIX */
+
+ /* Initial PAM. */
+ pam_service = ISSET(sudo_mode, MODE_LOGIN_SHELL) ?
+ def_pam_login_service : def_pam_service;
+ pam_status = pam_start(pam_service, pw->pw_name, &pam_conv, &pamh);
+ if (pam_status != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(NULL, pam_status);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_start(%s, %s, %p, %p): %s", pam_service, pw->pw_name,
+ &pam_conv, &pamh, errstr);
+ if (!quiet)
+ log_warningx(0, N_("unable to initialize PAM: %s"), errstr);
+ debug_return_int(AUTH_FATAL);
+ }
+
+ /* Initialize conversation function message filter. */
+ conv_filter_init();
+
+ /*
+ * Set PAM_RUSER to the invoking user (the "from" user).
+ * Solaris 7 and below require PAM_RHOST to be set if PAM_RUSER is.
+ * Note: PAM_RHOST may cause a DNS lookup on Linux in libaudit.
+ */
+ if (def_pam_ruser) {
+ rc = pam_set_item(pamh, PAM_RUSER, user_name);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_set_item(pamh, PAM_RUSER, %s): %s", user_name, errstr);
+ }
+ }
+ if (def_pam_rhost) {
+ rc = pam_set_item(pamh, PAM_RHOST, user_host);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_set_item(pamh, PAM_RHOST, %s): %s", user_host, errstr);
+ }
+ }
+
+#if defined(__LINUX_PAM__) || defined(__sun__)
+ /*
+ * Some PAM modules assume PAM_TTY is set and will misbehave (or crash)
+ * if it is not. Known offenders include pam_lastlog and pam_time.
+ */
+ if (ttypath == NULL)
+ ttypath = "";
+#endif
+ if (ttypath != NULL) { // -V547
+ rc = pam_set_item(pamh, PAM_TTY, ttypath);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_set_item(pamh, PAM_TTY, %s): %s", ttypath, errstr);
+ }
+ }
+
+ /*
+ * If PAM session and setcred support is disabled we don't
+ * need to keep a sudo process around to close the session.
+ */
+ if (!def_pam_session && !def_pam_setcred)
+ auth->end_session = NULL;
+
+ debug_return_int(AUTH_SUCCESS);
+}
+
+int
+sudo_pam_init(struct passwd *pw, sudo_auth *auth)
+{
+ return sudo_pam_init2(pw, auth, false);
+}
+
+#ifdef _AIX
+int
+sudo_pam_init_quiet(struct passwd *pw, sudo_auth *auth)
+{
+ return sudo_pam_init2(pw, auth, true);
+}
+#endif /* _AIX */
+
+int
+sudo_pam_verify(struct passwd *pw, char *prompt, sudo_auth *auth, struct sudo_conv_callback *callback)
+{
+ const char *envccname;
+ const char *s;
+ int *pam_status = (int *) auth->data;
+ debug_decl(sudo_pam_verify, SUDOERS_DEBUG_AUTH);
+
+ def_prompt = prompt; /* for converse */
+ getpass_error = false; /* set by converse if user presses ^C */
+ conv_callback = callback; /* passed to conversation function */
+
+ /* Set KRB5CCNAME from the user environment if not set to propagate this
+ * information to PAM modules that may use it to authentication. */
+ envccname = sudo_getenv("KRB5CCNAME");
+ if (envccname == NULL && user_ccname != NULL) {
+ if (sudo_setenv("KRB5CCNAME", user_ccname, true) != 0) {
+ sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO,
+ "unable to set KRB5CCNAME");
+ debug_return_int(AUTH_FAILURE);
+ }
+ }
+
+ /* PAM_SILENT prevents the authentication service from generating output. */
+ *pam_status = pam_authenticate(pamh, PAM_SILENT);
+
+ /* Restore KRB5CCNAME to its original value. */
+ if (envccname == NULL && sudo_unsetenv("KRB5CCNAME") != 0) {
+ sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO,
+ "unable to restore KRB5CCNAME");
+ debug_return_int(AUTH_FAILURE);
+ }
+
+ if (getpass_error) {
+ /* error or ^C from tgetpass() */
+ debug_return_int(AUTH_INTR);
+ }
+ switch (*pam_status) {
+ case PAM_SUCCESS:
+ debug_return_int(AUTH_SUCCESS);
+ case PAM_AUTH_ERR:
+ case PAM_AUTHINFO_UNAVAIL:
+ case PAM_MAXTRIES:
+ case PAM_PERM_DENIED:
+ sudo_debug_printf(SUDO_DEBUG_WARN|SUDO_DEBUG_LINENO,
+ "pam_authenticate: %d", *pam_status);
+ debug_return_int(AUTH_FAILURE);
+ default:
+ s = sudo_pam_strerror(pamh, *pam_status);
+ log_warningx(0, N_("PAM authentication error: %s"), s);
+ debug_return_int(AUTH_FATAL);
+ }
+}
+
+int
+sudo_pam_approval(struct passwd *pw, sudo_auth *auth, bool exempt)
+{
+ const char *s;
+ int rc, status = AUTH_SUCCESS;
+ int *pam_status = (int *) auth->data;
+ debug_decl(sudo_pam_approval, SUDOERS_DEBUG_AUTH);
+
+ if (def_pam_acct_mgmt) {
+ rc = pam_acct_mgmt(pamh, PAM_SILENT);
+ switch (rc) {
+ case PAM_SUCCESS:
+ break;
+ case PAM_AUTH_ERR:
+ log_warningx(0, N_("account validation failure, "
+ "is your account locked?"));
+ status = AUTH_FATAL;
+ break;
+ case PAM_NEW_AUTHTOK_REQD:
+ /* Ignore if user is exempt from password restrictions. */
+ if (exempt) {
+ rc = *pam_status;
+ break;
+ }
+ /* New password required, try to change it. */
+ log_warningx(0, N_("Account or password is "
+ "expired, reset your password and try again"));
+ rc = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
+ if (rc == PAM_SUCCESS)
+ break;
+ s = pam_strerror(pamh, rc);
+ log_warningx(0, N_("unable to change expired password: %s"), s);
+ status = AUTH_FAILURE;
+ break;
+ case PAM_AUTHTOK_EXPIRED:
+ /* Ignore if user is exempt from password restrictions. */
+ if (exempt) {
+ rc = *pam_status;
+ break;
+ }
+ /* Password expired, cannot be updated by user. */
+ log_warningx(0,
+ N_("Password expired, contact your system administrator"));
+ status = AUTH_FATAL;
+ break;
+ case PAM_ACCT_EXPIRED:
+ log_warningx(0,
+ N_("Account expired or PAM config lacks an \"account\" "
+ "section for sudo, contact your system administrator"));
+ status = AUTH_FATAL;
+ break;
+ case PAM_AUTHINFO_UNAVAIL:
+ case PAM_MAXTRIES:
+ case PAM_PERM_DENIED:
+ s = sudo_pam_strerror(pamh, rc);
+ log_warningx(0, N_("PAM account management error: %s"), s);
+ status = AUTH_FAILURE;
+ break;
+ default:
+ s = sudo_pam_strerror(pamh, rc);
+ log_warningx(0, N_("PAM account management error: %s"), s);
+ status = AUTH_FATAL;
+ break;
+ }
+ *pam_status = rc;
+ }
+ debug_return_int(status);
+}
+
+int
+sudo_pam_cleanup(struct passwd *pw, sudo_auth *auth, bool force)
+{
+ int *pam_status = (int *) auth->data;
+ debug_decl(sudo_pam_cleanup, SUDOERS_DEBUG_AUTH);
+
+ /* If successful, we can't close the session until sudo_pam_end_session() */
+ if (force || *pam_status != PAM_SUCCESS || auth->end_session == NULL) {
+ *pam_status = pam_end(pamh, *pam_status | PAM_DATA_SILENT);
+ pamh = NULL;
+ }
+ debug_return_int(*pam_status == PAM_SUCCESS ? AUTH_SUCCESS : AUTH_FAILURE);
+}
+
+int
+sudo_pam_begin_session(struct passwd *pw, char **user_envp[], sudo_auth *auth)
+{
+ int rc, status = AUTH_SUCCESS;
+ int *pam_status = (int *) auth->data;
+ const char *errstr;
+ debug_decl(sudo_pam_begin_session, SUDOERS_DEBUG_AUTH);
+
+ /*
+ * If there is no valid user we cannot open a PAM session.
+ * This is not an error as sudo can run commands with arbitrary
+ * uids, it just means we are done from a session management standpoint.
+ */
+ if (pw == NULL) {
+ if (pamh != NULL) {
+ rc = pam_end(pamh, PAM_SUCCESS | PAM_DATA_SILENT);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_end: %s", errstr);
+ }
+ pamh = NULL;
+ }
+ goto done;
+ }
+
+ /*
+ * Update PAM_USER to reference the user we are running the command
+ * as, as opposed to the user we authenticated as.
+ */
+ rc = pam_set_item(pamh, PAM_USER, pw->pw_name);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_set_item(pamh, PAM_USER, %s): %s", pw->pw_name, errstr);
+ }
+
+ /*
+ * Reinitialize credentials when changing the user.
+ * We don't worry about a failure from pam_setcred() since with
+ * stacked PAM auth modules a failure from one module may override
+ * PAM_SUCCESS from another. For example, given a non-local user,
+ * pam_unix will fail but pam_ldap or pam_sss may succeed, but if
+ * pam_unix is first in the stack, pam_setcred() will fail.
+ */
+ if (def_pam_setcred) {
+ rc = pam_setcred(pamh, PAM_REINITIALIZE_CRED);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_setcred: %s", errstr);
+ def_pam_setcred = false;
+ }
+ }
+
+ if (def_pam_session) {
+ /*
+ * We use PAM_SILENT to prevent pam_lastlog from printing last login
+ * information except when explicitly running a shell.
+ */
+ const bool silent = !ISSET(sudo_mode, MODE_SHELL|MODE_LOGIN_SHELL);
+ rc = pam_open_session(pamh, silent ? PAM_SILENT : 0);
+ switch (rc) {
+ case PAM_SUCCESS:
+ break;
+ case PAM_SESSION_ERR:
+ /* Treat PAM_SESSION_ERR as a non-fatal error. */
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_open_session: %s", errstr);
+ /* Avoid closing session that was not opened. */
+ def_pam_session = false;
+ break;
+ default:
+ /* Unexpected session failure, treat as fatal error. */
+ *pam_status = rc;
+ errstr = sudo_pam_strerror(pamh, rc);
+ log_warningx(0, N_("%s: %s"), "pam_open_session", errstr);
+ rc = pam_end(pamh, *pam_status | PAM_DATA_SILENT);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_end: %s", errstr);
+ }
+ pamh = NULL;
+ status = AUTH_FATAL;
+ goto done;
+ }
+ }
+
+#ifdef HAVE_PAM_GETENVLIST
+ /*
+ * Update environment based on what is stored in pamh.
+ * If no authentication is done we will only have environment
+ * variables if pam_env is called via session.
+ */
+ if (user_envp != NULL) {
+ char **pam_envp = pam_getenvlist(pamh);
+ if (pam_envp != NULL) {
+ /* Merge pam env with user env. */
+ if (!env_init(*user_envp) || !env_merge(pam_envp))
+ status = AUTH_FATAL;
+ *user_envp = env_get();
+ (void)env_init(NULL);
+ free(pam_envp);
+ /* XXX - we leak any duplicates that were in pam_envp */
+ }
+ }
+#endif /* HAVE_PAM_GETENVLIST */
+
+done:
+ debug_return_int(status);
+}
+
+int
+sudo_pam_end_session(struct passwd *pw, sudo_auth *auth)
+{
+ int rc, status = AUTH_SUCCESS;
+ const char *errstr;
+ debug_decl(sudo_pam_end_session, SUDOERS_DEBUG_AUTH);
+
+ if (pamh != NULL) {
+ /*
+ * Update PAM_USER to reference the user we are running the command
+ * as, as opposed to the user we authenticated as.
+ * XXX - still needed now that session init is in parent?
+ */
+ rc = pam_set_item(pamh, PAM_USER, pw->pw_name);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_set_item(pamh, PAM_USER, %s): %s", pw->pw_name, errstr);
+ }
+ if (def_pam_session) {
+ rc = pam_close_session(pamh, PAM_SILENT);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_close_session: %s", errstr);
+ }
+ }
+ if (def_pam_setcred) {
+ rc = pam_setcred(pamh, PAM_DELETE_CRED | PAM_SILENT);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_setcred: %s", errstr);
+ }
+ }
+ rc = pam_end(pamh, PAM_SUCCESS | PAM_DATA_SILENT);
+ if (rc != PAM_SUCCESS) {
+ errstr = sudo_pam_strerror(pamh, rc);
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "pam_end: %s", errstr);
+ status = AUTH_FATAL;
+ }
+ pamh = NULL;
+ }
+
+ debug_return_int(status);
+}
+
+#define PROMPT_IS_PASSWORD(_p) \
+ (strncmp((_p), "Password:", 9) == 0 && \
+ ((_p)[9] == '\0' || ((_p)[9] == ' ' && (_p)[10] == '\0')))
+
+#ifdef PAM_TEXT_DOMAIN
+# define PAM_PROMPT_IS_PASSWORD(_p) \
+ (strcmp((_p), dgt(PAM_TEXT_DOMAIN, "Password:")) == 0 || \
+ strcmp((_p), dgt(PAM_TEXT_DOMAIN, "Password: ")) == 0 || \
+ PROMPT_IS_PASSWORD(_p))
+#else
+# define PAM_PROMPT_IS_PASSWORD(_p) PROMPT_IS_PASSWORD(_p)
+#endif /* PAM_TEXT_DOMAIN */
+
+/*
+ * We use the PAM prompt in preference to sudo's as long
+ * as passprompt_override is not set and:
+ * a) the (translated) sudo prompt matches /^Password: ?/
+ * or:
+ * b) the PAM prompt itself *doesn't* match /^Password: ?/
+ * or /^username's Password: ?/
+ *
+ * The intent is to use the PAM prompt for things like
+ * challenge-response, otherwise use sudo's prompt.
+ * There may also be cases where a localized translation
+ * of "Password: " exists for PAM but not for sudo.
+ */
+static bool
+use_pam_prompt(const char *pam_prompt)
+{
+ size_t user_len;
+ debug_decl(use_pam_prompt, SUDOERS_DEBUG_AUTH);
+
+ /* Always use sudo prompt if passprompt_override is set. */
+ if (def_passprompt_override)
+ debug_return_bool(false);
+
+ /* If sudo prompt matches "^Password: ?$", use PAM prompt. */
+ if (PROMPT_IS_PASSWORD(def_prompt))
+ debug_return_bool(true);
+
+ /* If PAM prompt matches "^Password: ?$", use sudo prompt. */
+ if (PAM_PROMPT_IS_PASSWORD(pam_prompt))
+ debug_return_bool(false);
+
+ /*
+ * Some PAM modules use "^username's Password: ?$" instead of
+ * "^Password: ?" so check for that too.
+ */
+ user_len = strlen(user_name);
+ if (strncmp(pam_prompt, user_name, user_len) == 0) {
+ const char *cp = pam_prompt + user_len;
+ if (strncmp(cp, "'s Password:", 12) == 0 &&
+ (cp[12] == '\0' || (cp[12] == ' ' && cp[13] == '\0')))
+ debug_return_bool(false);
+ }
+
+ /* Otherwise, use the PAM prompt. */
+ debug_return_bool(true);
+}
+
+static bool
+is_filtered(const char *msg)
+{
+ bool filtered = false;
+
+ if (conv_filter != NULL) {
+ struct conv_filter *filt = conv_filter;
+ while (filt->msg != NULL) {
+ if (strncmp(msg, filt->msg, filt->msglen) == 0) {
+ filtered = true;
+ break;
+ }
+ filt++;
+ }
+ }
+ return filtered;
+}
+
+/*
+ * ``Conversation function'' for PAM <-> human interaction.
+ */
+static int
+converse(int num_msg, PAM_CONST struct pam_message **msg,
+ struct pam_response **reply_out, void *vcallback)
+{
+ struct sudo_conv_callback *callback = NULL;
+ struct pam_response *reply;
+ const char *prompt;
+ char *pass;
+ int n, type;
+ int ret = PAM_SUCCESS;
+ debug_decl(converse, SUDOERS_DEBUG_AUTH);
+
+ if (num_msg <= 0 || num_msg > PAM_MAX_NUM_MSG) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "invalid number of PAM messages: %d", num_msg);
+ debug_return_int(PAM_CONV_ERR);
+ }
+ sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+ "number of PAM messages: %d", num_msg);
+
+ if ((reply = calloc(num_msg, sizeof(struct pam_response))) == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ debug_return_int(PAM_BUF_ERR);
+ }
+ *reply_out = reply;
+
+ if (vcallback != NULL)
+ callback = *((struct sudo_conv_callback **)vcallback);
+
+ for (n = 0; n < num_msg; n++) {
+ PAM_CONST struct pam_message *pm = PAM_MSG_GET(msg, n);
+
+ type = SUDO_CONV_PROMPT_ECHO_OFF;
+ switch (pm->msg_style) {
+ case PAM_PROMPT_ECHO_ON:
+ type = SUDO_CONV_PROMPT_ECHO_ON;
+ FALLTHROUGH;
+ case PAM_PROMPT_ECHO_OFF:
+ /* Error out if the last password read was interrupted. */
+ if (getpass_error)
+ goto done;
+
+ /* Choose either the sudo prompt or the PAM one. */
+ prompt = use_pam_prompt(pm->msg) ? pm->msg : def_prompt;
+
+ /* Read the password unless interrupted. */
+ pass = auth_getpass(prompt, type, callback);
+ if (pass == NULL) {
+ /* Error (or ^C) reading password, don't try again. */
+ getpass_error = true;
+ ret = PAM_CONV_ERR;
+ goto done;
+ }
+ if (strlen(pass) >= PAM_MAX_RESP_SIZE) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "password longer than %d", PAM_MAX_RESP_SIZE);
+ ret = PAM_CONV_ERR;
+ explicit_bzero(pass, strlen(pass));
+ goto done;
+ }
+ reply[n].resp = pass; /* auth_getpass() malloc's a copy */
+ break;
+ case PAM_TEXT_INFO:
+ if (pm->msg != NULL && !is_filtered(pm->msg))
+ sudo_printf(SUDO_CONV_INFO_MSG|SUDO_CONV_PREFER_TTY,
+ "%s\n", pm->msg);
+ break;
+ case PAM_ERROR_MSG:
+ if (pm->msg != NULL)
+ sudo_printf(SUDO_CONV_ERROR_MSG|SUDO_CONV_PREFER_TTY,
+ "%s\n", pm->msg);
+ break;
+ default:
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unsupported message style: %d", pm->msg_style);
+ ret = PAM_CONV_ERR;
+ goto done;
+ }
+ }
+
+done:
+ if (ret != PAM_SUCCESS) {
+ /* Zero and free allocated memory and return an error. */
+ for (n = 0; n < num_msg; n++) {
+ struct pam_response *pr = &reply[n];
+
+ if (pr->resp != NULL) {
+ freezero(pr->resp, strlen(pr->resp));
+ pr->resp = NULL;
+ }
+ }
+ free(reply);
+ *reply_out = NULL;
+ }
+ debug_return_int(ret);
+}
+
+#endif /* HAVE_PAM */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-03 19:18:22 +0000