Adding upstream version 1.9.15p5.upstream/1.9.15p5upstream

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

1 files changed, 1444 insertions, 0 deletions

diff --git a/plugins/sudoers/env.c b/plugins/sudoers/env.c
new file mode 100644
index 0000000..e3f28f1
--- /dev/null
+++ b/plugins/sudoers/env.c
@@ -0,0 +1,1444 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2000-2005, 2007-2023
+ *	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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#if defined(HAVE_STDINT_H)
+# include <stdint.h>
+#elif defined(HAVE_INTTYPES_H)
+# include <inttypes.h>
+#endif
+#ifdef HAVE_LOGIN_CAP_H
+# include <login_cap.h>
+# ifndef LOGIN_SETENV
+#  define LOGIN_SETENV	0
+# endif
+#endif /* HAVE_LOGIN_CAP_H */
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <pwd.h>
+
+#include <sudoers.h>
+
+/*
+ * Flags used in rebuild_env()
+ */
+#undef DID_TERM
+#define DID_TERM	0x00000001
+#undef DID_PATH
+#define DID_PATH	0x00000002
+#undef DID_HOME
+#define DID_HOME	0x00000004
+#undef DID_SHELL
+#define DID_SHELL	0x00000008
+#undef DID_LOGNAME
+#define DID_LOGNAME	0x00000010
+#undef DID_USER
+#define DID_USER    	0x00000020
+#undef DID_LOGIN
+#define DID_LOGIN   	0x00000040
+#undef DID_MAIL
+#define DID_MAIL   	0x00000080
+#undef DID_MAX
+#define DID_MAX    	0x0000ffff
+
+#undef KEPT_TERM
+#define KEPT_TERM	0x00010000
+#undef KEPT_PATH
+#define KEPT_PATH	0x00020000
+#undef KEPT_HOME
+#define KEPT_HOME	0x00040000
+#undef KEPT_SHELL
+#define KEPT_SHELL	0x00080000
+#undef KEPT_LOGNAME
+#define KEPT_LOGNAME	0x00100000
+#undef KEPT_USER
+#define KEPT_USER    	0x00200000
+#undef KEPT_LOGIN
+#define KEPT_LOGIN	0x00400000
+#undef KEPT_MAIL
+#define KEPT_MAIL	0x00800000
+#undef KEPT_MAX
+#define KEPT_MAX    	0xffff0000
+
+/*
+ * AIX sets the LOGIN environment variable too.
+ */
+#ifdef _AIX
+# define KEPT_USER_VARIABLES (KEPT_LOGIN|KEPT_LOGNAME|KEPT_USER)
+#else
+# define KEPT_USER_VARIABLES (KEPT_LOGNAME|KEPT_USER)
+#endif
+
+/*
+ * Functions to open, close and parse an environment file, either
+ * a system file such as /etc/environment or one specified in sudoers.
+ */
+struct sudoers_env_file {
+    void * (*open)(const char *);
+    void   (*close)(void *);
+    char * (*next)(void *, int *);
+};
+
+/*
+ * State for a local environment file.
+ */
+struct env_file_local {
+    FILE *fp;
+    char *line;
+    size_t linesize;
+};
+
+struct environment {
+    char **envp;		/* pointer to the new environment */
+    char **old_envp;		/* pointer the old environment we allocated */
+    size_t env_size;		/* size of new_environ in char **'s */
+    size_t env_len;		/* number of slots used, not counting NULL */
+};
+
+/*
+ * Copy of the sudo-managed environment.
+ */
+static struct environment env;
+
+/*
+ * Default table of "bad" variables to remove from the environment.
+ * XXX - how to omit TERMCAP if it starts with '/'?
+ */
+static const char *initial_badenv_table[] = {
+    "IFS",
+    "CDPATH",
+    "LOCALDOMAIN",
+    "RES_OPTIONS",
+    "HOSTALIASES",
+    "NLSPATH",
+    "PATH_LOCALE",
+    "LD_*",
+    "_RLD*",
+#ifdef __hpux
+    "SHLIB_PATH",
+#endif /* __hpux */
+#ifdef _AIX
+    "LDR_*",
+    "LIBPATH",
+    "AUTHSTATE",
+#endif
+#ifdef __APPLE__
+    "DYLD_*",
+#endif
+#ifdef HAVE_KERB5
+    "KRB5_CONFIG*",
+    "KRB5_KTNAME",
+#endif /* HAVE_KERB5 */
+#ifdef HAVE_SECURID
+    "VAR_ACE",
+    "USR_ACE",
+    "DLC_ACE",
+#endif /* HAVE_SECURID */
+    "TERMINFO",			/* terminfo, exclusive path to terminfo files */
+    "TERMINFO_DIRS",		/* terminfo, path(s) to terminfo files */
+    "TERMPATH",			/* termcap, path(s) to termcap files */
+    "TERMCAP",			/* XXX - only if it starts with '/' */
+    "ENV",			/* ksh, file to source before script runs */
+    "BASH_ENV",			/* bash, file to source before script runs */
+    "PS4",			/* bash, prefix for lines in xtrace mode */
+    "GLOBIGNORE",		/* bash, globbing patterns to ignore */
+    "BASHOPTS",			/* bash, initial "shopt -s" options */
+    "SHELLOPTS",		/* bash, initial "set -o" options */
+    "JAVA_TOOL_OPTIONS",	/* java, extra command line options */
+    "PERLIO_DEBUG",		/* perl, debugging output file */
+    "PERLLIB",			/* perl, search path for modules/includes */
+    "PERL5LIB",			/* perl 5, search path for modules/includes */
+    "PERL5OPT",			/* perl 5, extra command line options */
+    "PERL5DB",			/* perl 5, command used to load debugger */
+    "FPATH",			/* ksh, search path for functions */
+    "NULLCMD",			/* zsh, command for null file redirection */
+    "READNULLCMD",		/* zsh, command for null file redirection */
+    "ZDOTDIR",			/* zsh, search path for dot files */
+    "TMPPREFIX",		/* zsh, prefix for temporary files */
+    "PYTHONHOME",		/* python, module search path */
+    "PYTHONPATH",		/* python, search path */
+    "PYTHONINSPECT",		/* python, allow inspection */
+    "PYTHONUSERBASE",		/* python, per user site-packages directory */
+    "RUBYLIB",			/* ruby, library load path */
+    "RUBYOPT",			/* ruby, extra command line options */
+    "*=()*",			/* bash functions */
+    NULL
+};
+
+/*
+ * Default table of variables to check for '%' and '/' characters.
+ */
+static const char *initial_checkenv_table[] = {
+    "COLORTERM",
+    "LANG",
+    "LANGUAGE",
+    "LC_*",
+    "LINGUAS",
+    "TERM",
+    "TZ",
+    NULL
+};
+
+/*
+ * Default table of variables to preserve in the environment.
+ */
+static const char *initial_keepenv_table[] = {
+    "COLORS",
+    "DISPLAY",
+    "HOSTNAME",
+    "KRB5CCNAME",
+    "LS_COLORS",
+    "PATH",
+    "PS1",
+    "PS2",
+    "XAUTHORITY",
+    "XAUTHORIZATION",
+    "XDG_CURRENT_DESKTOP",
+    NULL
+};
+
+/*
+ * Free our copy (or copies) of the environment.
+ * This function is only safe to call after the command has executed.
+ */
+void
+env_free(void)
+{
+    sudoers_gc_remove(GC_PTR, env.envp);
+    free(env.envp);
+    sudoers_gc_remove(GC_PTR, env.old_envp);
+    free(env.old_envp);
+    memset(&env, 0, sizeof(env));
+}
+
+/*
+ * Initialize env based on envp.
+ */
+bool
+env_init(char * const envp[])
+{
+    char * const *ep;
+    size_t len;
+    debug_decl(env_init, SUDOERS_DEBUG_ENV);
+
+    if (envp == NULL) {
+	/* Free the old envp we allocated, if any. */
+	sudoers_gc_remove(GC_PTR, env.old_envp);
+	free(env.old_envp);
+
+	/*
+	 * Reset to initial state but keep a pointer to what we allocated
+	 * since it will be passed to execve(2).
+	 */
+	env.old_envp = env.envp;
+	env.envp = NULL;
+	env.env_size = 0;
+	env.env_len = 0;
+    } else {
+	/* Make private copy of envp. */
+	for (ep = envp; *ep != NULL; ep++)
+	    continue;
+	len = (size_t)(ep - envp);
+
+	env.env_len = len;
+	env.env_size = len + 1 + 128;
+	env.envp = reallocarray(NULL, env.env_size, sizeof(char *));
+	if (env.envp == NULL) {
+	    env.env_size = 0;
+	    env.env_len = 0;
+	    sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	    debug_return_bool(false);
+	}
+	sudoers_gc_add(GC_PTR, env.envp);
+#ifdef ENV_DEBUG
+	memset(env.envp, 0, env.env_size * sizeof(char *));
+#endif
+	memcpy(env.envp, envp, len * sizeof(char *));
+	env.envp[len] = NULL;
+
+	/* Free the old envp we allocated, if any. */
+	sudoers_gc_remove(GC_PTR, env.old_envp);
+	free(env.old_envp);
+	env.old_envp = NULL;
+    }
+
+    debug_return_bool(true);
+}
+
+/*
+ * Getter for private copy of the environment.
+ */
+char **
+env_get(void)
+{
+    return env.envp;
+}
+
+/*
+ * Swap the old and new copies of the environment.
+ */
+bool
+env_swap_old(void)
+{
+    char **old_envp;
+
+    if (env.old_envp == NULL)
+	return false;
+    old_envp = env.old_envp;
+    env.old_envp = env.envp;
+    env.envp = old_envp;
+    return true;
+}
+
+/*
+ * Similar to putenv(3) but operates on sudo's private copy of the
+ * environment (not environ) and it always overwrites.  The dupcheck param
+ * determines whether we need to verify that the variable is not already set.
+ * Will only overwrite an existing variable if overwrite is set.
+ * Does not include warnings or debugging to avoid recursive calls.
+ */
+int
+sudo_putenv_nodebug(char *str, bool dupcheck, bool overwrite)
+{
+    char **ep;
+    const char *equal;
+    bool found = false;
+
+    /* Some putenv(3) implementations check for NULL. */
+    if (str == NULL) {
+	errno = EINVAL;
+	return -1;
+    }
+
+    /* The string must contain a '=' char but not start with one. */
+    equal = strchr(str, '=');
+    if (equal == NULL || equal == str) {
+	errno = EINVAL;
+	return -1;
+    }
+
+    /* Make sure there is room for the new entry plus a NULL. */
+    if (env.env_size > 2 && env.env_len > env.env_size - 2) {
+	char **nenvp;
+	size_t nsize;
+
+	if (env.env_size > SIZE_MAX - 128) {
+	    sudo_warnx_nodebug(U_("internal error, %s overflow"),
+		"sudo_putenv_nodebug");
+	    errno = EOVERFLOW;
+	    return -1;
+	}
+	nsize = env.env_size + 128;
+	if (nsize > SIZE_MAX / sizeof(char *)) {
+	    sudo_warnx_nodebug(U_("internal error, %s overflow"),
+		"sudo_putenv_nodebug");
+	    errno = EOVERFLOW;
+	    return -1;
+	}
+	sudoers_gc_remove(GC_PTR, env.envp);
+	nenvp = reallocarray(env.envp, nsize, sizeof(char *));
+	if (nenvp == NULL) {
+	    sudoers_gc_add(GC_PTR, env.envp);
+	    return -1;
+	}
+	sudoers_gc_add(GC_PTR, nenvp);
+	env.envp = nenvp;
+	env.env_size = nsize;
+#ifdef ENV_DEBUG
+	memset(env.envp + env.env_len, 0,
+	    (env.env_size - env.env_len) * sizeof(char *));
+#endif
+    }
+
+#ifdef ENV_DEBUG
+    if (env.envp[env.env_len] != NULL) {
+	errno = EINVAL;
+	return -1;
+    }
+#endif
+
+    if (dupcheck) {
+	size_t len = (size_t)(equal - str) + 1;
+	for (ep = env.envp; *ep != NULL; ep++) {
+	    if (strncmp(str, *ep, len) == 0) {
+		if (overwrite)
+		    *ep = str;
+		found = true;
+		break;
+	    }
+	}
+	/* Prune out extra instances of the variable we just overwrote. */
+	if (found && overwrite) {
+	    while (*++ep != NULL) {
+		if (strncmp(str, *ep, len) == 0) {
+		    char **cur = ep;
+		    while ((*cur = *(cur + 1)) != NULL)
+			cur++;
+		    ep--;
+		}
+	    }
+	    env.env_len = (size_t)(ep - env.envp);
+	}
+    }
+
+    if (!found) {
+	ep = env.envp + env.env_len;
+	env.env_len++;
+	*ep++ = str;
+	*ep = NULL;
+    }
+    return 0;
+}
+
+/*
+ * Similar to putenv(3) but operates on sudo's private copy of the
+ * environment (not environ) and it always overwrites.  The dupcheck param
+ * determines whether we need to verify that the variable is not already set.
+ * Will only overwrite an existing variable if overwrite is set.
+ */
+static int
+sudo_putenv(char *str, bool dupcheck, bool overwrite)
+{
+    int ret;
+    debug_decl(sudo_putenv, SUDOERS_DEBUG_ENV);
+
+    sudo_debug_printf(SUDO_DEBUG_INFO, "sudo_putenv: %s", str);
+
+    ret = sudo_putenv_nodebug(str, dupcheck, overwrite);
+    if (ret == -1) {
+#ifdef ENV_DEBUG
+	if (env.envp[env.env_len] != NULL) {
+	    sudo_warnx("%s",
+		U_("sudo_putenv: corrupted envp, length mismatch"));
+	}
+#endif
+    }
+    debug_return_int(ret);
+}
+
+/*
+ * Similar to setenv(3) but operates on a private copy of the environment.
+ * The dupcheck param determines whether we need to verify that the variable
+ * is not already set.
+ */
+static int
+sudo_setenv2(const char *var, const char *val, bool dupcheck, bool overwrite)
+{
+    char *estring;
+    size_t esize;
+    int ret = -1;
+    debug_decl(sudo_setenv2, SUDOERS_DEBUG_ENV);
+
+    esize = strlen(var) + 1 + strlen(val) + 1;
+    if ((estring = malloc(esize)) == NULL) {
+	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+	    "unable to allocate memory");
+	debug_return_int(-1);
+    }
+
+    /* Build environment string and insert it. */
+    if (strlcpy(estring, var, esize) >= esize ||
+	strlcat(estring, "=", esize) >= esize ||
+	strlcat(estring, val, esize) >= esize) {
+
+	sudo_warnx(U_("internal error, %s overflow"), __func__);
+	errno = EOVERFLOW;
+    } else {
+	ret = sudo_putenv(estring, dupcheck, overwrite);
+    }
+    if (ret == -1)
+	free(estring);
+    else
+	sudoers_gc_add(GC_PTR, estring);
+    debug_return_int(ret);
+}
+
+/*
+ * Similar to setenv(3) but operates on a private copy of the environment.
+ */
+int
+sudo_setenv(const char *var, const char *val, int overwrite)
+{
+    return sudo_setenv2(var, val, true, (bool)overwrite);
+}
+
+/*
+ * Similar to unsetenv(3) but operates on a private copy of the environment.
+ * Does not include warnings or debugging to avoid recursive calls.
+ */
+int
+sudo_unsetenv_nodebug(const char *var)
+{
+    char **ep = env.envp;
+    size_t len;
+
+    if (ep == NULL || var == NULL || *var == '\0' || strchr(var, '=') != NULL) {
+	errno = EINVAL;
+	return -1;
+    }
+
+    len = strlen(var);
+    while (*ep != NULL) {
+	if (strncmp(var, *ep, len) == 0 && (*ep)[len] == '=') {
+	    /* Found it; shift remainder + NULL over by one. */
+	    char **cur = ep;
+	    while ((*cur = *(cur + 1)) != NULL)
+		cur++;
+	    env.env_len--;
+	    /* Keep going, could be multiple instances of the var. */
+	} else {
+	    ep++;
+	}
+    }
+    return 0;
+}
+
+/*
+ * Similar to unsetenv(3) but operates on a private copy of the environment.
+ */
+int
+sudo_unsetenv(const char *name)
+{
+    int ret;
+    debug_decl(sudo_unsetenv, SUDOERS_DEBUG_ENV);
+
+    sudo_debug_printf(SUDO_DEBUG_INFO, "sudo_unsetenv: %s", name);
+
+    ret = sudo_unsetenv_nodebug(name);
+
+    debug_return_int(ret);
+}
+
+/*
+ * Similar to getenv(3) but operates on a private copy of the environment.
+ * Does not include warnings or debugging to avoid recursive calls.
+ */
+char *
+sudo_getenv_nodebug(const char *name)
+{
+    char **ep, *val = NULL;
+    size_t namelen = 0;
+
+    if (env.env_len != 0) {
+	/* For BSD compatibility, treat '=' in name like end of string. */
+	while (name[namelen] != '\0' && name[namelen] != '=')
+	    namelen++;
+	for (ep = env.envp; *ep != NULL; ep++) {
+	    if (strncmp(*ep, name, namelen) == 0 && (*ep)[namelen] == '=') {
+		val = *ep + namelen + 1;
+		break;
+	    }
+	}
+    }
+    return val;
+}
+
+/*
+ * Similar to getenv(3) but operates on a private copy of the environment.
+ */
+char *
+sudo_getenv(const char *name)
+{
+    char *val;
+    debug_decl(sudo_getenv, SUDOERS_DEBUG_ENV);
+
+    sudo_debug_printf(SUDO_DEBUG_INFO, "sudo_getenv: %s", name);
+
+    val = sudo_getenv_nodebug(name);
+
+    debug_return_str(val);
+}
+
+/*
+ * Check for var against patterns in the specified environment list.
+ * Returns true if the variable was found, else false.
+ */
+static bool
+matches_env_list(const char *var, struct list_members *list, bool *full_match)
+{
+    struct list_member *cur;
+    bool is_logname = false;
+    debug_decl(matches_env_list, SUDOERS_DEBUG_ENV);
+
+    switch (*var) {
+    case 'L':
+	if (strncmp(var, "LOGNAME=", 8) == 0)
+	    is_logname = true;
+#ifdef _AIX
+	else if (strncmp(var, "LOGIN=", 6) == 0)
+	    is_logname = true;
+#endif
+	break;
+    case 'U':
+	if (strncmp(var, "USER=", 5) == 0)
+	    is_logname = true;
+	break;
+    }
+
+    if (is_logname) {
+	/*
+	 * We treat LOGIN, LOGNAME and USER specially.
+	 * If one is preserved/deleted we want to preserve/delete them all.
+	 */
+	SLIST_FOREACH(cur, list, entries) {
+	    if (matches_env_pattern(cur->value, "LOGNAME", full_match) ||
+#ifdef _AIX
+		matches_env_pattern(cur->value, "LOGIN", full_match) ||
+#endif
+		matches_env_pattern(cur->value, "USER", full_match))
+		debug_return_bool(true);
+	}
+    } else {
+	SLIST_FOREACH(cur, list, entries) {
+	    if (matches_env_pattern(cur->value, var, full_match))
+		debug_return_bool(true);
+	}
+    }
+    debug_return_bool(false);
+}
+
+/*
+ * Check the env_delete blocklist.
+ * Returns true if the variable was found, else false.
+ */
+static bool
+matches_env_delete(const char *var)
+{
+    bool full_match;	/* unused */
+    debug_decl(matches_env_delete, SUDOERS_DEBUG_ENV);
+
+    /* Skip anything listed in env_delete. */
+    debug_return_bool(matches_env_list(var, &def_env_delete, &full_match));
+}
+
+/*
+ * Verify the TZ environment variable is safe.
+ * On many systems it is possible to set this to a pathname.
+ */
+static bool
+tz_is_safe(const char *tzval)
+{
+    const char *cp;
+    char lastch;
+    debug_decl(tz_is_safe, SUDOERS_DEBUG_ENV);
+
+    /* tzcode treats a value beginning with a ':' as a path. */
+    if (tzval[0] == ':')
+	tzval++;
+
+    /* Reject fully-qualified TZ that doesn't being with the zoneinfo dir. */
+    if (tzval[0] == '/') {
+#ifdef _PATH_ZONEINFO
+	if (strncmp(tzval, _PATH_ZONEINFO, sizeof(_PATH_ZONEINFO) - 1) != 0 ||
+	    tzval[sizeof(_PATH_ZONEINFO) - 1] != '/')
+	    debug_return_bool(false);
+#else
+	/* Assume the worst. */
+	debug_return_bool(false);
+#endif
+    }
+
+    /*
+     * Make sure TZ only contains printable non-space characters
+     * and does not contain a '..' path element.
+     */
+    lastch = '/';
+    for (cp = tzval; *cp != '\0'; cp++) {
+	if (isspace((unsigned char)*cp) || !isprint((unsigned char)*cp))
+	    debug_return_bool(false);
+	if (lastch == '/' && cp[0] == '.' && cp[1] == '.' &&
+	    (cp[2] == '/' || cp[2] == '\0'))
+	    debug_return_bool(false);
+	lastch = *cp;
+    }
+
+    /* Reject extra long TZ values (even if not a path). */
+    if ((size_t)(cp - tzval) >= PATH_MAX)
+	debug_return_bool(false);
+
+    debug_return_bool(true);
+}
+
+/*
+ * Apply the env_check list.
+ * Returns true if the variable is allowed, false if denied
+ * or -1 if no match.
+ */
+static int
+matches_env_check(const char *var, bool *full_match)
+{
+    int keepit = -1;
+    debug_decl(matches_env_check, SUDOERS_DEBUG_ENV);
+
+    /* Skip anything listed in env_check that includes '/' or '%'. */
+    if (matches_env_list(var, &def_env_check, full_match)) {
+	if (strncmp(var, "TZ=", 3) == 0) {
+	    /* Special case for TZ */
+	    keepit = tz_is_safe(var + 3);
+	} else {
+	    const char *val = strchr(var, '=');
+	    if (val != NULL)
+		keepit = !strpbrk(val + 1, "/%");
+	}
+    }
+    debug_return_int(keepit);
+}
+
+/*
+ * Check the env_keep list.
+ * Returns true if the variable is allowed else false.
+ */
+static bool
+matches_env_keep(const struct sudoers_context *ctx, const char *var,
+    bool *full_match)
+{
+    bool keepit = false;
+    debug_decl(matches_env_keep, SUDOERS_DEBUG_ENV);
+
+    /* Preserve SHELL variable for "sudo -s". */
+    if (ISSET(ctx->mode, MODE_SHELL) && strncmp(var, "SHELL=", 6) == 0) {
+	keepit = true;
+    } else if (matches_env_list(var, &def_env_keep, full_match)) {
+	keepit = true;
+    }
+    debug_return_bool(keepit);
+}
+
+/*
+ * Look up var in the env_delete and env_check.
+ * Returns true if we should delete the variable, else false.
+ */
+static bool
+env_should_delete(const char *var)
+{
+    int delete_it;
+    bool full_match = false;
+    debug_decl(env_should_delete, SUDOERS_DEBUG_ENV);
+
+    delete_it = matches_env_delete(var);
+    if (!delete_it)
+	delete_it = matches_env_check(var, &full_match) == false;
+
+    sudo_debug_printf(SUDO_DEBUG_INFO, "delete %s: %s",
+	var, delete_it ? "YES" : "NO");
+    debug_return_bool(delete_it);
+}
+
+/*
+ * Lookup var in the env_check and env_keep lists.
+ * Returns true if the variable is allowed else false.
+ */
+static bool
+env_should_keep(const struct sudoers_context *ctx, const char *var)
+{
+    int keepit;
+    bool full_match = false;
+    const char *cp;
+    debug_decl(env_should_keep, SUDOERS_DEBUG_ENV);
+
+    keepit = matches_env_check(var, &full_match);
+    if (keepit == -1)
+	keepit = matches_env_keep(ctx, var, &full_match);
+
+    /* Skip bash functions unless we matched on the value as well as name. */
+    if (keepit && !full_match) {
+	if ((cp = strchr(var, '=')) != NULL) {
+	    if (strncmp(cp, "=() ", 4) == 0)
+		keepit = false;
+	}
+    }
+    sudo_debug_printf(SUDO_DEBUG_INFO, "keep %s: %s",
+	var, keepit == true ? "YES" : "NO");
+    debug_return_bool(keepit == true);
+}
+
+#ifdef HAVE_PAM
+/*
+ * Merge another environment with our private copy.
+ * Only overwrite an existing variable if it is not
+ * being preserved from the user's environment.
+ * Returns true on success or false on failure.
+ */
+bool
+env_merge(const struct sudoers_context *ctx, char * const envp[])
+{
+    char * const *ep;
+    bool ret = true;
+    debug_decl(env_merge, SUDOERS_DEBUG_ENV);
+
+    for (ep = envp; *ep != NULL; ep++) {
+	/* XXX - avoid checking value here, should only check name */
+	bool overwrite = def_env_reset ? !env_should_keep(ctx, *ep) : env_should_delete(*ep);
+	if (sudo_putenv(*ep, true, overwrite) == -1) {
+	    /* XXX cannot undo on failure */
+	    ret = false;
+	    break;
+	}
+    }
+    debug_return_bool(ret);
+}
+#endif /* HAVE_PAM */
+
+static void
+env_update_didvar(const char *ep, unsigned int *didvar)
+{
+    switch (*ep) {
+	case 'H':
+	    if (strncmp(ep, "HOME=", 5) == 0)
+		SET(*didvar, DID_HOME);
+	    break;
+	case 'L':
+#ifdef _AIX
+	    if (strncmp(ep, "LOGIN=", 8) == 0)
+		SET(*didvar, DID_LOGIN);
+#endif
+	    if (strncmp(ep, "LOGNAME=", 8) == 0)
+		SET(*didvar, DID_LOGNAME);
+	    break;
+	case 'M':
+	    if (strncmp(ep, "MAIL=", 5) == 0)
+		SET(*didvar, DID_MAIL);
+	    break;
+	case 'P':
+	    if (strncmp(ep, "PATH=", 5) == 0)
+		SET(*didvar, DID_PATH);
+	    break;
+	case 'S':
+	    if (strncmp(ep, "SHELL=", 6) == 0)
+		SET(*didvar, DID_SHELL);
+	    break;
+	case 'T':
+	    if (strncmp(ep, "TERM=", 5) == 0)
+		SET(*didvar, DID_TERM);
+	    break;
+	case 'U':
+	    if (strncmp(ep, "USER=", 5) == 0)
+		SET(*didvar, DID_USER);
+	    break;
+    }
+}
+
+#define CHECK_PUTENV(a, b, c)	do {					       \
+    if (sudo_putenv((char *)(a), (b), (c)) == -1) {			       \
+	goto bad;							       \
+    }									       \
+} while (0)
+
+#define CHECK_SETENV2(a, b, c, d)	do {				       \
+    if (sudo_setenv2((char *)(a), (b), (c), (d)) == -1) {		       \
+	goto bad;							       \
+    }									       \
+} while (0)
+
+/*
+ * Build a new environment and either clear potentially dangerous
+ * variables from the old one or start with a clean slate.
+ * Also adds sudo-specific variables (SUDO_*).
+ * Returns true on success or false on failure.
+ */
+bool
+rebuild_env(const struct sudoers_context *ctx)
+{
+    char **ep, *cp, *ps1;
+    char idbuf[STRLEN_MAX_UNSIGNED(uid_t) + 1];
+    unsigned int didvar;
+    bool reset_home = false;
+    int len;
+    debug_decl(rebuild_env, SUDOERS_DEBUG_ENV);
+
+    /*
+     * Either clean out the environment or reset to a safe default.
+     */
+    ps1 = NULL;
+    didvar = 0;
+    env.env_len = 0;
+    env.env_size = 128;
+    sudoers_gc_remove(GC_PTR, env.old_envp);
+    free(env.old_envp);
+    env.old_envp = env.envp;
+    env.envp = reallocarray(NULL, env.env_size, sizeof(char *));
+    if (env.envp == NULL) {
+	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+	    "unable to allocate memory");
+	env.env_size = 0;
+	goto bad;
+    }
+    sudoers_gc_add(GC_PTR, env.envp);
+#ifdef ENV_DEBUG
+    memset(env.envp, 0, env.env_size * sizeof(char *));
+#else
+    env.envp[0] = NULL;
+#endif
+
+    /* Reset HOME based on target user if configured to. */
+    if (ISSET(ctx->mode, MODE_RUN)) {
+	if (def_always_set_home ||
+	    ISSET(ctx->mode, MODE_RESET_HOME | MODE_LOGIN_SHELL) || 
+	    (ISSET(ctx->mode, MODE_SHELL) && def_set_home))
+	    reset_home = true;
+    }
+
+    if (def_env_reset || ISSET(ctx->mode, MODE_LOGIN_SHELL)) {
+	/*
+	 * If starting with a fresh environment, initialize it based on
+	 * /etc/environment or login.conf.  For "sudo -i" we want those
+	 * variables to override the invoking user's environment, so we
+	 * defer reading them until later.
+	 */
+	if (!ISSET(ctx->mode, MODE_LOGIN_SHELL)) {
+#ifdef HAVE_LOGIN_CAP_H
+	    /* Insert login class environment variables. */
+	    if (ctx->runas.class) {
+		login_cap_t *lc = login_getclass(ctx->runas.class);
+		if (lc != NULL) {
+		    setusercontext(lc, ctx->runas.pw,
+			ctx->runas.pw->pw_uid, LOGIN_SETPATH|LOGIN_SETENV);
+		    login_close(lc);
+		}
+	    }
+#endif /* HAVE_LOGIN_CAP_H */
+#ifdef _PATH_ENVIRONMENT
+	    /* Insert system-wide environment variables. */
+	    if (!read_env_file(ctx, _PATH_ENVIRONMENT, true, false))
+		sudo_warn("%s", _PATH_ENVIRONMENT);
+#endif
+	    for (ep = env.envp; *ep; ep++)
+		env_update_didvar(*ep, &didvar);
+	}
+
+	/* Pull in vars we want to keep from the old environment. */
+	if (env.old_envp != NULL) {
+	    for (ep = env.old_envp; *ep; ep++) {
+		bool keepit;
+
+		/*
+		 * Look up the variable in the env_check and env_keep lists.
+		 */
+		keepit = env_should_keep(ctx, *ep);
+
+		/*
+		 * Do SUDO_PS1 -> PS1 conversion.
+		 * This must happen *after* env_should_keep() is called.
+		 */
+		if (strncmp(*ep, "SUDO_PS1=", 9) == 0)
+		    ps1 = *ep + 5;
+
+		if (keepit) {
+		    /* Preserve variable. */
+		    CHECK_PUTENV(*ep, true, false);
+		    env_update_didvar(*ep, &didvar);
+		}
+	    }
+	}
+	didvar |= didvar << 16;		/* convert DID_* to KEPT_* */
+
+	/*
+	 * Add in defaults.  In -i mode these come from the runas user,
+	 * otherwise they may be from the user's environment (depends
+	 * on sudoers options).
+	 */
+	if (ISSET(ctx->mode, MODE_LOGIN_SHELL)) {
+	    CHECK_SETENV2("SHELL", ctx->runas.pw->pw_shell,
+		ISSET(didvar, DID_SHELL), true);
+#ifdef _AIX
+	    CHECK_SETENV2("LOGIN", ctx->runas.pw->pw_name,
+		ISSET(didvar, DID_LOGIN), true);
+#endif
+	    CHECK_SETENV2("LOGNAME", ctx->runas.pw->pw_name,
+		ISSET(didvar, DID_LOGNAME), true);
+	    CHECK_SETENV2("USER", ctx->runas.pw->pw_name,
+		ISSET(didvar, DID_USER), true);
+	} else {
+	    /* We will set LOGNAME later in the def_set_logname case. */
+	    if (!def_set_logname) {
+#ifdef _AIX
+		if (!ISSET(didvar, DID_LOGIN))
+		    CHECK_SETENV2("LOGIN", ctx->user.name, false, true);
+#endif
+		if (!ISSET(didvar, DID_LOGNAME))
+		    CHECK_SETENV2("LOGNAME", ctx->user.name, false, true);
+		if (!ISSET(didvar, DID_USER))
+		    CHECK_SETENV2("USER", ctx->user.name, false, true);
+	    }
+	}
+
+	/* If we didn't keep HOME, reset it based on target user. */
+	if (!ISSET(didvar, KEPT_HOME))
+	    reset_home = true;
+
+	/*
+	 * Set MAIL to target user in -i mode or if MAIL is not preserved
+	 * from user's environment.
+	 */
+	if (ISSET(ctx->mode, MODE_LOGIN_SHELL) || !ISSET(didvar, KEPT_MAIL)) {
+	    if (_PATH_MAILDIR[sizeof(_PATH_MAILDIR) - 2] == '/') {
+		len = asprintf(&cp, "MAIL=%s%s", _PATH_MAILDIR,
+		    ctx->runas.pw->pw_name);
+	    } else {
+		len = asprintf(&cp, "MAIL=%s/%s", _PATH_MAILDIR,
+		    ctx->runas.pw->pw_name);
+	    }
+	    if (len == -1)
+		    goto bad;
+	    if (sudo_putenv(cp, ISSET(didvar, DID_MAIL), true) == -1) {
+		free(cp);
+		goto bad;
+	    }
+	    sudoers_gc_add(GC_PTR, cp);
+	}
+    } else {
+	/*
+	 * Copy environ entries as long as they don't match env_delete or
+	 * env_check.
+	 */
+	if (env.old_envp != NULL) {
+	    for (ep = env.old_envp; *ep; ep++) {
+		/* Add variable unless it matches a blocklist. */
+		if (!env_should_delete(*ep)) {
+		    if (strncmp(*ep, "SUDO_PS1=", 9) == 0)
+			ps1 = *ep + 5;
+		    else if (strncmp(*ep, "SHELL=", 6) == 0)
+			SET(didvar, DID_SHELL);
+		    else if (strncmp(*ep, "PATH=", 5) == 0)
+			SET(didvar, DID_PATH);
+		    else if (strncmp(*ep, "TERM=", 5) == 0)
+			SET(didvar, DID_TERM);
+		    CHECK_PUTENV(*ep, true, false);
+		}
+	    }
+	}
+    }
+    /* Replace the PATH envariable with a secure one? */
+    if (def_secure_path && !user_is_exempt(ctx)) {
+	CHECK_SETENV2("PATH", def_secure_path, true, true);
+	SET(didvar, DID_PATH);
+    }
+
+    /*
+     * Set LOGIN, LOGNAME, and USER to target if "set_logname" is not
+     * disabled.  We skip this if we are running a login shell (because
+     * they have already been set).
+     */
+    if (def_set_logname && !ISSET(ctx->mode, MODE_LOGIN_SHELL)) {
+	if ((didvar & KEPT_USER_VARIABLES) == 0) {
+	    /* Nothing preserved, set them all. */
+#ifdef _AIX
+	    CHECK_SETENV2("LOGIN", ctx->runas.pw->pw_name, true, true);
+#endif
+	    CHECK_SETENV2("LOGNAME", ctx->runas.pw->pw_name, true, true);
+	    CHECK_SETENV2("USER", ctx->runas.pw->pw_name, true, true);
+	} else if ((didvar & KEPT_USER_VARIABLES) != KEPT_USER_VARIABLES) {
+	    /*
+	     * Preserved some of LOGIN, LOGNAME, USER but not all.
+	     * Make the unset ones match so we don't end up with some
+	     * set to the invoking user and others set to the runas user.
+	     */
+	    if (ISSET(didvar, KEPT_LOGNAME))
+		cp = sudo_getenv("LOGNAME");
+#ifdef _AIX
+	    else if (ISSET(didvar, KEPT_LOGIN))
+		cp = sudo_getenv("LOGIN");
+#endif
+	    else if (ISSET(didvar, KEPT_USER))
+		cp = sudo_getenv("USER");
+	    else
+		cp = NULL;
+	    if (cp != NULL) {
+#ifdef _AIX
+		if (!ISSET(didvar, KEPT_LOGIN))
+		    CHECK_SETENV2("LOGIN", cp, true, true);
+#endif
+		if (!ISSET(didvar, KEPT_LOGNAME))
+		    CHECK_SETENV2("LOGNAME", cp, true, true);
+		if (!ISSET(didvar, KEPT_USER))
+		    CHECK_SETENV2("USER", cp, true, true);
+	    }
+	}
+    }
+
+    /* Set $HOME to target user if not preserving user's value. */
+    if (reset_home)
+	CHECK_SETENV2("HOME", ctx->runas.pw->pw_dir, true, true);
+
+    /* Provide default values for $SHELL, $TERM and $PATH if not set. */
+    if (!ISSET(didvar, DID_SHELL))
+	CHECK_SETENV2("SHELL", ctx->runas.pw->pw_shell, false, false);
+    if (!ISSET(didvar, DID_TERM))
+	CHECK_PUTENV("TERM=unknown", false, false);
+    if (!ISSET(didvar, DID_PATH))
+	CHECK_SETENV2("PATH", _PATH_STDPATH, false, true);
+
+    /* Set PS1 if SUDO_PS1 is set. */
+    if (ps1 != NULL)
+	CHECK_PUTENV(ps1, true, true);
+
+    /* Add the SUDO_COMMAND envariable (cmnd + args). */
+    if (ctx->user.cmnd_args) {
+	/*
+	 * We limit ctx->user.cmnd_args to 4096 bytes to avoid an execve(2)
+	 * failure for very long argument vectors.  The command's environment
+	 * also counts against the ARG_MAX limit.
+	 */
+	len = asprintf(&cp, "SUDO_COMMAND=%s %.*s", ctx->user.cmnd, 4096,
+	    ctx->user.cmnd_args);
+	if (len == -1)
+	    goto bad;
+	if (sudo_putenv(cp, true, true) == -1) {
+	    free(cp);
+	    goto bad;
+	}
+	sudoers_gc_add(GC_PTR, cp);
+    } else {
+	CHECK_SETENV2("SUDO_COMMAND", ctx->user.cmnd, true, true);
+    }
+
+    /* Add the SUDO_USER, SUDO_UID, SUDO_GID environment variables. */
+    CHECK_SETENV2("SUDO_USER", ctx->user.name, true, true);
+    (void)snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) ctx->user.uid);
+    CHECK_SETENV2("SUDO_UID", idbuf, true, true);
+    (void)snprintf(idbuf, sizeof(idbuf), "%u", (unsigned int) ctx->user.gid);
+    CHECK_SETENV2("SUDO_GID", idbuf, true, true);
+
+    debug_return_bool(true);
+
+bad:
+    sudo_warn("%s", U_("unable to rebuild the environment"));
+    debug_return_bool(false);
+}
+
+/*
+ * Insert all environment variables in envp into the private copy
+ * of the environment.
+ * Returns true on success or false on failure.
+ */
+bool
+insert_env_vars(char * const envp[])
+{
+    char * const *ep;
+    bool ret = true;
+    debug_decl(insert_env_vars, SUDOERS_DEBUG_ENV);
+
+    /* Add user-specified environment variables. */
+    if (envp != NULL) {
+	for (ep = envp; *ep != NULL; ep++) {
+	    /* XXX - no undo on failure */
+	    if (sudo_putenv(*ep, true, true) == -1) {
+		ret = false;
+		break;
+	    }
+	}
+    }
+    debug_return_bool(ret);
+}
+
+/*
+ * Validate the list of environment variables passed in on the command
+ * line against env_delete, env_check, and env_keep.
+ * Calls log_warning() if any specified variables are not allowed.
+ * Returns true if allowed, else false.
+ */
+bool
+validate_env_vars(const struct sudoers_context *ctx, char * const env_vars[])
+{
+    char * const *ep;
+    char errbuf[4096];
+    char *errpos = errbuf;
+    bool okvar, ret = true;
+    debug_decl(validate_env_vars, SUDOERS_DEBUG_ENV);
+
+    if (env_vars == NULL)
+	debug_return_bool(true);	/* nothing to do */
+
+    /* Add user-specified environment variables. */
+    for (ep = env_vars; *ep != NULL; ep++) {
+	char *eq = strchr(*ep, '=');
+	if (eq == NULL || eq == *ep) {
+	    /* Must be in the form var=val. */
+	    okvar = false;
+	} else if (def_secure_path && !user_is_exempt(ctx) &&
+	    strncmp(*ep, "PATH=", 5) == 0) {
+	    okvar = false;
+	} else if (def_env_reset) {
+	    okvar = env_should_keep(ctx, *ep);
+	} else {
+	    okvar = !env_should_delete(*ep);
+	}
+	if (okvar == false) {
+	    /* Not allowed, append to error buffer if space remains. */
+	    if (errpos < &errbuf[sizeof(errbuf)]) {
+		const size_t varlen = strcspn(*ep, "=");
+		const size_t errsize = sizeof(errbuf) - (size_t)(errpos - errbuf);
+		int len = snprintf(errpos, errsize, "%s%.*s",
+		    errpos != errbuf ? ", " : "", (int)varlen, *ep);
+		if (len >= ssizeof(errbuf) - (errpos - errbuf)) {
+		    memcpy(&errbuf[sizeof(errbuf) - 4], "...", 4);
+		    errpos = &errbuf[sizeof(errbuf)];
+		} else {
+		    errpos += len;
+		}
+	    }
+	}
+    }
+    if (errpos != errbuf) {
+	/* XXX - audit? */
+	log_warningx(ctx, 0,
+	    N_("sorry, you are not allowed to set the following environment variables: %s"), errbuf);
+	ret = false;
+    }
+    debug_return_bool(ret);
+}
+
+static void *
+env_file_open_local(const char *path)
+{
+    struct env_file_local *efl;
+    debug_decl(env_file_open_local, SUDOERS_DEBUG_ENV);
+
+    efl = calloc(1, sizeof(*efl));
+    if (efl != NULL) {
+	if ((efl->fp = fopen(path, "r")) == NULL) {
+	    if (errno != ENOENT) {
+		free(efl);
+		efl = NULL;
+	    }
+	}
+    }
+    debug_return_ptr(efl);
+}
+
+static void
+env_file_close_local(void *cookie)
+{
+    struct env_file_local *efl = cookie;
+    debug_decl(env_file_close_local, SUDOERS_DEBUG_ENV);
+
+    if (efl != NULL) {
+	if (efl->fp != NULL)
+	    fclose(efl->fp);
+	free(efl->line);
+	free(efl);
+    }
+    debug_return;
+}
+
+/*
+ * Parse /etc/environment lines ala AIX and Linux.
+ * Lines may be in either of three formats:
+ *  NAME=VALUE
+ *  NAME="VALUE"
+ *  NAME='VALUE'
+ * with an optional "export" prefix so the shell can source the file.
+ * Invalid lines, blank lines, or lines consisting solely of a comment
+ * character are skipped.
+ */
+static char *
+env_file_next_local(void *cookie, int *errnum)
+{
+    struct env_file_local *efl = cookie;
+    char *var, *val, *ret = NULL;
+    size_t var_len, val_len;
+    debug_decl(env_file_next_local, SUDOERS_DEBUG_ENV);
+
+    *errnum = 0;
+    if (efl->fp == NULL)
+	debug_return_ptr(NULL);
+
+    for (;;) {
+	if (sudo_parseln(&efl->line, &efl->linesize, NULL, efl->fp, PARSELN_CONT_IGN) == -1) {
+	    if (!feof(efl->fp))
+		*errnum = errno;
+	    break;
+	}
+
+	/* Skip blank or comment lines */
+	if (*(var = efl->line) == '\0')
+	    continue;
+
+	/* Skip optional "export " */
+	if (strncmp(var, "export", 6) == 0 && isspace((unsigned char) var[6])) {
+	    var += 7;
+	    while (isspace((unsigned char) *var)) {
+		var++;
+	    }
+	}
+
+	/* Must be of the form name=["']value['"] */
+	for (val = var; *val != '\0' && *val != '='; val++)
+	    continue;
+	if (var == val || *val != '=')
+	    continue;
+	var_len = (size_t)(val - var);
+	val_len = strlen(++val);
+
+	/* Strip leading and trailing single/double quotes */
+	if ((val[0] == '\'' || val[0] == '\"') && val_len > 1 && val[0] == val[val_len - 1]) {
+	    val[val_len - 1] = '\0';
+	    val++;
+	    val_len -= 2;
+	}
+
+	if ((ret = malloc(var_len + 1 + val_len + 1)) == NULL) {
+	    *errnum = errno;
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"unable to allocate memory");
+	} else {
+	    memcpy(ret, var, var_len + 1); /* includes '=' */
+	    memcpy(ret + var_len + 1, val, val_len + 1); /* includes NUL */
+	    sudoers_gc_add(GC_PTR, ret);
+	}
+	break;
+    }
+    debug_return_str(ret);
+}
+
+static struct sudoers_env_file env_file_sudoers = {
+    env_file_open_local,
+    env_file_close_local,
+    env_file_next_local
+};
+
+static struct sudoers_env_file env_file_system = {
+    env_file_open_local,
+    env_file_close_local,
+    env_file_next_local
+};
+
+void
+register_env_file(void * (*ef_open)(const char *), void (*ef_close)(void *),
+    char * (*ef_next)(void *, int *), bool sys)
+{
+    struct sudoers_env_file *ef = sys ? &env_file_system : &env_file_sudoers;
+
+    ef->open = ef_open;
+    ef->close = ef_close;
+    ef->next = ef_next;
+}
+
+bool
+read_env_file(const struct sudoers_context *ctx, const char *path,
+    bool overwrite, bool restricted)
+{
+    struct sudoers_env_file *ef;
+    bool ret = true;
+    char *envstr;
+    void *cookie;
+    int errnum;
+    debug_decl(read_env_file, SUDOERS_DEBUG_ENV);
+
+    /*
+     * The environment file may be handled differently depending on
+     * whether it is specified in sudoers or the system.
+     */
+    if (path == def_env_file || path == def_restricted_env_file)
+	ef = &env_file_sudoers;
+    else
+	ef = &env_file_system;
+
+    cookie = ef->open(path);
+    if (cookie == NULL)
+	debug_return_bool(false);
+
+    for (;;) {
+	/* Keep reading until EOF or error. */
+	if ((envstr = ef->next(cookie, &errnum)) == NULL) {
+	    if (errnum != 0)
+		ret = false;
+	    break;
+	}
+
+	/*
+	 * If the env file is restricted, apply env_check and env_keep
+	 * when env_reset is set or env_delete when it is not.
+	 */
+	if (restricted) {
+	    if (def_env_reset ? !env_should_keep(ctx, envstr) : env_should_delete(envstr)) {
+		free(envstr);
+		continue;
+	    }
+	}
+	if (sudo_putenv(envstr, true, overwrite) == -1) {
+	    /* XXX - no undo on failure */
+	    ret = false;
+	    break;
+	}
+    }
+    ef->close(cookie);
+
+    debug_return_bool(ret);
+}
+
+bool
+init_envtables(void)
+{
+    struct list_member *cur;
+    const char **p;
+    debug_decl(init_envtables, SUDOERS_DEBUG_ENV);
+
+    /* Fill in the "env_delete" list. */
+    for (p = initial_badenv_table; *p; p++) {
+	cur = calloc(1, sizeof(struct list_member));
+	if (cur == NULL || (cur->value = strdup(*p)) == NULL) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"unable to allocate memory");
+	    free(cur);
+	    debug_return_bool(false);
+	}
+	SLIST_INSERT_HEAD(&def_env_delete, cur, entries);
+    }
+
+    /* Fill in the "env_check" list. */
+    for (p = initial_checkenv_table; *p; p++) {
+	cur = calloc(1, sizeof(struct list_member));
+	if (cur == NULL || (cur->value = strdup(*p)) == NULL) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"unable to allocate memory");
+	    free(cur);
+	    debug_return_bool(false);
+	}
+	SLIST_INSERT_HEAD(&def_env_check, cur, entries);
+    }
+
+    /* Fill in the "env_keep" list. */
+    for (p = initial_keepenv_table; *p; p++) {
+	cur = calloc(1, sizeof(struct list_member));
+	if (cur == NULL || (cur->value = strdup(*p)) == NULL) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"unable to allocate memory");
+	    free(cur);
+	    debug_return_bool(false);
+	}
+	SLIST_INSERT_HEAD(&def_env_keep, cur, entries);
+    }
+    debug_return_bool(true);
+}