Adding upstream version 1.9.15p5.upstream/1.9.15p5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 325 insertions, 0 deletions

diff --git a/plugins/sudoers/check.c b/plugins/sudoers/check.c
new file mode 100644
index 0000000..4356dd1
--- /dev/null
+++ b/plugins/sudoers/check.c
@@ -0,0 +1,325 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 1993-1996,1998-2005, 2007-2018
+ *	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>
+
+#include <sys/types.h>			/* for ssize_t */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <time.h>
+#include <errno.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include <sudoers.h>
+#include <timestamp.h>
+
+/*
+ * Get passwd entry for the user we are going to authenticate as.
+ * By default, this is the user invoking sudo.  In the most common
+ * case, this matches ctx->user.pw or ctx->runas.pw.
+ */
+static struct passwd *
+get_authpw(struct sudoers_context *ctx, unsigned int mode)
+{
+    struct passwd *pw = NULL;
+    debug_decl(get_authpw, SUDOERS_DEBUG_AUTH);
+
+    if (ISSET(mode, (MODE_CHECK|MODE_LIST))) {
+	/* In list mode we always prompt for the user's password. */
+	sudo_pw_addref(ctx->user.pw);
+	pw = ctx->user.pw;
+    } else {
+	if (def_rootpw) {
+	    if ((pw = sudo_getpwuid(ROOT_UID)) == NULL) {
+		log_warningx(ctx, SLOG_SEND_MAIL, N_("unknown uid %u"),
+		    ROOT_UID);
+	    }
+	} else if (def_runaspw) {
+	    if ((pw = sudo_getpwnam(def_runas_default)) == NULL) {
+		log_warningx(ctx, SLOG_SEND_MAIL,
+		    N_("unknown user %s"), def_runas_default);
+	    }
+	} else if (def_targetpw) {
+	    if (ctx->runas.pw->pw_name == NULL) {
+		/* This should never be NULL as we fake up the passwd struct */
+		log_warningx(ctx, SLOG_RAW_MSG, N_("unknown uid %u"),
+		    (unsigned int) ctx->runas.pw->pw_uid);
+	    } else {
+		sudo_pw_addref(ctx->runas.pw);
+		pw = ctx->runas.pw;
+	    }
+	} else {
+	    sudo_pw_addref(ctx->user.pw);
+	    pw = ctx->user.pw;
+	}
+    }
+
+    debug_return_ptr(pw);
+}
+
+/*
+ * Returns AUTH_SUCCESS if the user successfully authenticates,
+ * AUTH_FAILURE if not or AUTH_ERROR on error.
+ */
+int
+check_user(struct sudoers_context *ctx, unsigned int validated,
+    unsigned int mode)
+{
+    struct getpass_closure closure = { 0 };
+    struct sudo_conv_callback callback;
+    int status = TS_ERROR;
+    int ret = AUTH_ERROR;
+    bool exempt = false;
+    char *prompt;
+    debug_decl(check_user, SUDOERS_DEBUG_AUTH);
+
+    /*
+     * In intercept mode, only check the user if configured to do so.
+     * We already have a session so no need to init the auth subsystem.
+     */
+    if (ISSET(ctx->mode, MODE_POLICY_INTERCEPTED)) {
+	if (!def_intercept_authenticate) {
+	    debug_return_int(AUTH_SUCCESS);
+	}
+    }
+
+    /*
+     * Init authentication system regardless of whether we need a password.
+     * Required for proper PAM session support.
+     */
+    if ((closure.auth_pw = get_authpw(ctx, mode)) == NULL)
+	debug_return_int(AUTH_ERROR);
+    if (sudo_auth_init(ctx, closure.auth_pw, mode) != AUTH_SUCCESS) {
+	sudo_pw_delref(closure.auth_pw);
+	debug_return_int(AUTH_ERROR);
+    }
+    closure.ctx = ctx;
+
+    /*
+     * Don't prompt for the root passwd or if the user is exempt.
+     * If the user is not changing uid/gid, no need for a password.
+     */
+    if (!def_authenticate || user_is_exempt(ctx)) {
+	sudo_debug_printf(SUDO_DEBUG_INFO, "%s: %s", __func__,
+	    !def_authenticate ? "authentication disabled" :
+	    "user exempt from authentication");
+	exempt = true;
+	ret = AUTH_SUCCESS;
+	goto done;
+    }
+    if (ctx->user.uid == 0 || (ctx->user.uid == ctx->runas.pw->pw_uid &&
+	(ctx->runas.gr == NULL ||
+	user_in_group(ctx->user.pw, ctx->runas.gr->gr_name)))) {
+#ifdef HAVE_SELINUX
+	if (ctx->runas.role == NULL && ctx->runas.type == NULL)
+#endif
+#ifdef HAVE_APPARMOR
+	if (ctx->runas.apparmor_profile == NULL)
+#endif
+#ifdef HAVE_PRIV_SET
+	if (ctx->runas.privs == NULL && ctx->runas.limitprivs == NULL)
+#endif
+	{
+	    sudo_debug_printf(SUDO_DEBUG_INFO,
+		"%s: user running command as self", __func__);
+	    ret = AUTH_SUCCESS;
+	    goto done;
+	}
+    }
+
+    /* Construct callback for getpass function. */
+    memset(&callback, 0, sizeof(callback));
+    callback.version = SUDO_CONV_CALLBACK_VERSION;
+    callback.closure = &closure;
+
+    /* Open, lock and read time stamp file if we are using it. */
+    if (!ISSET(mode, MODE_IGNORE_TICKET)) {
+	/* Open time stamp file and check its status. */
+	closure.cookie = timestamp_open(ctx);
+	if (closure.cookie != NULL) {
+	    if (timestamp_lock(closure.cookie, closure.auth_pw)) {
+		status = timestamp_status(closure.cookie, closure.auth_pw);
+	    }
+	}
+    }
+
+    switch (status) {
+    case TS_FATAL:
+	/* Fatal error (usually setuid failure), unsafe to proceed. */
+	goto done;
+
+    case TS_CURRENT:
+	/* Time stamp file is valid and current. */
+	if (!ISSET(validated, FLAG_CHECK_USER)) {
+	    ret = AUTH_SUCCESS;
+	    break;
+	}
+	sudo_debug_printf(SUDO_DEBUG_INFO,
+	    "%s: check user flag overrides time stamp", __func__);
+	FALLTHROUGH;
+
+    default:
+	if (ISSET(mode, MODE_NONINTERACTIVE) && !def_noninteractive_auth) {
+	    validated |= FLAG_NO_USER_INPUT;
+	    log_auth_failure(ctx, validated, 0);
+	    goto done;
+	}
+
+	/* Expand any escapes in the prompt. */
+	prompt = expand_prompt(ctx,
+	    ctx->user.prompt ? ctx->user.prompt : def_passprompt,
+	    closure.auth_pw->pw_name);
+	if (prompt == NULL)
+	    goto done;
+
+	ret = verify_user(ctx, closure.auth_pw, prompt, validated, &callback);
+	if (ret == AUTH_SUCCESS && closure.lectured)
+	    (void)set_lectured(ctx);	/* lecture error not fatal */
+	free(prompt);
+	break;
+    }
+
+done:
+    if (ret == AUTH_SUCCESS) {
+	/* The approval function may disallow a user post-authentication. */
+	ret = sudo_auth_approval(ctx, closure.auth_pw, validated, exempt);
+
+	/*
+	 * Only update time stamp if user validated and was approved.
+	 * Failure to update the time stamp is not a fatal error.
+	 */
+	if (ret == AUTH_SUCCESS && ISSET(validated, VALIDATE_SUCCESS)) {
+	    if (ISSET(mode, MODE_UPDATE_TICKET) && status != TS_ERROR)
+		(void)timestamp_update(closure.cookie, closure.auth_pw);
+	}
+    }
+    timestamp_close(closure.cookie);
+    sudo_auth_cleanup(ctx, closure.auth_pw, !ISSET(validated, VALIDATE_SUCCESS));
+    sudo_pw_delref(closure.auth_pw);
+
+    debug_return_int(ret);
+}
+
+/*
+ * Display sudo lecture (standard or custom).
+ * Returns true if the user was lectured, else false.
+ */
+void
+display_lecture(struct sudo_conv_callback *callback)
+{
+    struct getpass_closure *closure;
+    struct sudo_conv_message msg[2];
+    struct sudo_conv_reply repl[2];
+    char buf[BUFSIZ];
+    struct stat sb;
+    ssize_t nread;
+    int fd, msgcount = 1;
+    debug_decl(lecture, SUDOERS_DEBUG_AUTH);
+
+    if (callback == NULL || (closure = callback->closure) == NULL)
+	debug_return;
+
+    if (closure->lectured)
+	debug_return;
+
+    if (def_lecture == never ||
+	    (def_lecture == once && already_lectured(closure->ctx)))
+	debug_return;
+
+    memset(&msg, 0, sizeof(msg));
+    memset(&repl, 0, sizeof(repl));
+
+    if (def_lecture_file) {
+	fd = open(def_lecture_file, O_RDONLY|O_NONBLOCK);
+	if (fd != -1 && fstat(fd, &sb) == 0) {
+	    if (S_ISREG(sb.st_mode)) {
+		(void) fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) & ~O_NONBLOCK);
+		while ((nread = read(fd, buf, sizeof(buf) - 1)) > 0) {
+		    buf[nread] = '\0';
+		    msg[0].msg_type = SUDO_CONV_ERROR_MSG|SUDO_CONV_PREFER_TTY;
+		    msg[0].msg = buf;
+		    sudo_conv(1, msg, repl, NULL);
+		}
+		if (nread == 0) {
+		    close(fd);
+		    goto done;
+		}
+		log_warning(closure->ctx, SLOG_RAW_MSG,
+		    N_("error reading lecture file %s"), def_lecture_file);
+	    } else {
+		log_warningx(closure->ctx, SLOG_RAW_MSG,
+		    N_("ignoring lecture file %s: not a regular file"),
+		    def_lecture_file);
+	    }
+	} else {
+	    log_warning(closure->ctx, SLOG_RAW_MSG|SLOG_NO_STDERR,
+		N_("unable to open %s"), def_lecture_file);
+	}
+	if (fd != -1)
+	    close(fd);
+    }
+
+    /* Default sudo lecture. */
+    msg[0].msg_type = SUDO_CONV_ERROR_MSG|SUDO_CONV_PREFER_TTY;
+    msg[0].msg = _("\n"
+	"We trust you have received the usual lecture from the local System\n"
+	"Administrator. It usually boils down to these three things:\n\n"
+	"    #1) Respect the privacy of others.\n"
+	"    #2) Think before you type.\n"
+	"    #3) With great power comes great responsibility.\n\n");
+    if (!def_pwfeedback) {
+	msg[1].msg_type = SUDO_CONV_ERROR_MSG|SUDO_CONV_PREFER_TTY;
+	msg[1].msg = _("For security reasons, the password you type will not be visible.\n\n");
+	msgcount++;
+    }
+    sudo_conv(msgcount, msg, repl, NULL);
+
+done:
+    closure->lectured = true;
+    debug_return;
+}
+
+/*
+ * Checks if the user is exempt from supplying a password.
+ */
+bool
+user_is_exempt(const struct sudoers_context *ctx)
+{
+    bool ret = false;
+    debug_decl(user_is_exempt, SUDOERS_DEBUG_AUTH);
+
+    if (def_exempt_group) {
+	if (user_in_group(ctx->user.pw, def_exempt_group))
+	    ret = true;
+    }
+    debug_return_bool(ret);
+}