Adding upstream version 1.9.15p5.upstream/1.9.15p5upstream

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

1 files changed, 750 insertions, 0 deletions

diff --git a/plugins/sudoers/ldap_util.c b/plugins/sudoers/ldap_util.c
new file mode 100644
index 0000000..3cfd3b0
--- /dev/null
+++ b/plugins/sudoers/ldap_util.c
@@ -0,0 +1,750 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2013, 2016, 2018-2018 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * This code is derived from software contributed by Aaron Spangler.
+ *
+ * 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.
+ */
+
+/*
+ * 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>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <sudoers.h>
+#include <interfaces.h>
+#include <sudo_lbuf.h>
+#include <sudo_ldap.h>
+#include <sudo_digest.h>
+#include <gram.h>
+
+/*
+ * Returns true if the string pointed to by valp begins with an
+ * odd number of '!' characters.  Intervening blanks are ignored.
+ * Stores the address of the string after '!' removal in valp.
+ */
+bool
+sudo_ldap_is_negated(char **valp)
+{
+    char *val = *valp;
+    bool ret = false;
+    debug_decl(sudo_ldap_is_negated, SUDOERS_DEBUG_LDAP);
+
+    while (*val == '!') {
+	ret = !ret;
+	do {
+	    val++;
+	} while (isblank((unsigned char)*val));
+    }
+    *valp = val;
+    debug_return_bool(ret);
+}
+
+/*
+ * Parse an option string into a defaults structure.
+ * The members of def are pointers into optstr (which is modified).
+ */
+int
+sudo_ldap_parse_option(char *optstr, char **varp, char **valp)
+{
+    char *cp, *val = NULL;
+    char *var = optstr;
+    int op;
+    debug_decl(sudo_ldap_parse_option, SUDOERS_DEBUG_LDAP);
+
+    /* check for equals sign past first char */
+    cp = strchr(var, '=');
+    if (cp != NULL && cp > var) {
+	val = cp + 1;
+	op = cp[-1];	/* peek for += or -= cases */
+	if (op == '+' || op == '-') {
+	    /* case var+=val or var-=val */
+	    cp--;
+	} else {
+	    /* case var=val */
+	    op = true;
+	}
+	/* Trim whitespace between var and operator. */
+	while (cp > var && isblank((unsigned char)cp[-1]))
+	    cp--;
+	/* Truncate variable name. */
+	*cp = '\0';
+	/* Trim leading whitespace from val. */
+	while (isblank((unsigned char)*val))
+	    val++;
+	/* Strip double quotes if present. */
+	if (*val == '"') {
+	    char *ep = val + strlen(val);
+	    if (ep != val && ep[-1] == '"') {
+		val++;
+		ep[-1] = '\0';
+	    }
+	}
+    } else {
+	/* Boolean value, either true or false. */
+	op = sudo_ldap_is_negated(&var) ? false : true;
+    }
+    *varp = var;
+    *valp = val;
+
+    debug_return_int(op);
+}
+
+/*
+ * Convert an array of user/group names to a member list.
+ * The caller is responsible for freeing the returned struct member_list.
+ */
+static struct member_list *
+array_to_member_list(void *a, sudo_ldap_iter_t iter)
+{
+    struct member_list negated_members =
+	TAILQ_HEAD_INITIALIZER(negated_members);
+    struct member_list *members;
+    struct member *m;
+    char *val;
+    debug_decl(bv_to_member_list, SUDOERS_DEBUG_LDAP);
+
+    if ((members = calloc(1, sizeof(*members))) == NULL)
+	return NULL;
+    TAILQ_INIT(members);                      
+
+    while ((val = iter(&a)) != NULL) {
+	if ((m = calloc(1, sizeof(*m))) == NULL)
+	    goto bad;
+	m->negated = sudo_ldap_is_negated(&val);
+
+	switch (val[0]) {
+	case '\0':
+	    /* Empty RunAsUser means run as the invoking user. */
+	    m->type = MYSELF;
+	    break;
+	case '+':
+	    m->type = NETGROUP;
+	    break;
+	case '%':
+	    m->type = USERGROUP;
+	    break;
+	case 'A':
+	    if (strcmp(val, "ALL") == 0) {
+		m->type = ALL;
+		break;
+	    }
+	    FALLTHROUGH;
+	default:
+	    m->type = WORD;
+	    break;
+	}
+	if (m->type != ALL && m->type != MYSELF) {
+	    if ((m->name = strdup(val)) == NULL) {
+		free(m);
+		goto bad;
+	    }
+	}
+	if (m->negated)
+	    TAILQ_INSERT_TAIL(&negated_members, m, entries);
+	else
+	    TAILQ_INSERT_TAIL(members, m, entries);
+    }
+
+    /* Negated members take precedence so we insert them at the end. */
+    TAILQ_CONCAT(members, &negated_members, entries);
+    debug_return_ptr(members);
+bad:
+    free_members(&negated_members);
+    free_members(members);
+    free(members);
+    debug_return_ptr(NULL);
+}
+
+static bool
+is_address(char *host)
+{
+    union sudo_in_addr_un addr;
+    bool ret = false;
+    char *slash;
+    debug_decl(is_address, SUDOERS_DEBUG_LDAP);
+
+    /* Check for mask, not currently parsed. */
+    if ((slash = strchr(host, '/')) != NULL)
+	*slash = '\0';
+
+    if (inet_pton(AF_INET, host, &addr.ip4) == 1)
+	ret = true;
+#ifdef HAVE_STRUCT_IN6_ADDR
+    else if (inet_pton(AF_INET6, host, &addr.ip6) == 1)
+	ret = true;
+#endif
+
+    if (slash != NULL)
+	*slash = '/';
+
+    debug_return_bool(ret);
+}
+
+static struct member *
+host_to_member(char *host)
+{
+    struct member *m;
+    debug_decl(host_to_member, SUDOERS_DEBUG_LDAP);
+
+    if ((m = calloc(1, sizeof(*m))) == NULL)
+	goto oom;
+    m->negated = sudo_ldap_is_negated(&host);
+    switch (*host) {
+    case '+':
+	m->type = NETGROUP;
+	break;
+    case 'A':
+	if (strcmp(host, "ALL") == 0) {
+	    m->type = ALL;
+	    break;
+	}
+	FALLTHROUGH;
+    default:
+	if (is_address(host)) {
+	    m->type = NTWKADDR;
+	} else {
+	    m->type = WORD;
+	}
+	break;
+    }
+    if (m->type != ALL) {
+	if ((m->name = strdup(host)) == NULL)
+	    goto oom;
+    }
+
+    debug_return_ptr(m);
+oom:
+    free(m);
+    debug_return_ptr(NULL);
+}
+
+/*
+ * If a digest prefix is present, add it to struct command_digest_list
+ * and update cmnd to point to the command after the digest.
+ * Returns 1 if a digest was parsed, 0 if not and -1 on error.
+ */
+static int
+sudo_ldap_extract_digest(const char *cmnd, char **endptr,
+    struct command_digest_list *digests)
+{
+    const char *ep, *cp = cmnd;
+    struct command_digest *digest;
+    unsigned int digest_type = SUDO_DIGEST_INVALID;
+    debug_decl(sudo_ldap_extract_digest, SUDOERS_DEBUG_LDAP);
+
+    /*
+     * Check for and extract a digest prefix, e.g.
+     * sha224:d06a2617c98d377c250edd470fd5e576327748d82915d6e33b5f8db1 /bin/ls
+     */
+    if (cp[0] == 's' && cp[1] == 'h' && cp[2] == 'a') {
+	switch (cp[3]) {
+	case '2':
+	    if (cp[4] == '2' && cp[5] == '4')
+		digest_type = SUDO_DIGEST_SHA224;
+	    else if (cp[4] == '5' && cp[5] == '6')
+		digest_type = SUDO_DIGEST_SHA256;
+	    break;
+	case '3':
+	    if (cp[4] == '8' && cp[5] == '4')
+		digest_type = SUDO_DIGEST_SHA384;
+	    break;
+	case '5':
+	    if (cp[4] == '1' && cp[5] == '2')
+		digest_type = SUDO_DIGEST_SHA512;
+	    break;
+	}
+	if (digest_type != SUDO_DIGEST_INVALID) {
+	    cp += 6;
+	    while (isblank((unsigned char)*cp))
+		cp++;
+	    if (*cp == ':') {
+		cp++;
+		while (isblank((unsigned char)*cp))
+		    cp++;
+		ep = cp;
+		while (*ep != '\0' && !isblank((unsigned char)*ep) && *ep != ',')
+		    ep++;
+		if (isblank((unsigned char)*ep) || *ep == ',') {
+		    if ((digest = malloc(sizeof(*digest))) == NULL) {
+			sudo_warnx(U_("%s: %s"), __func__,
+			    U_("unable to allocate memory"));
+			debug_return_int(-1);
+		    }
+		    digest->digest_type = digest_type;
+		    digest->digest_str = strndup(cp, (size_t)(ep - cp));
+		    if (digest->digest_str == NULL) {
+			sudo_warnx(U_("%s: %s"), __func__,
+			    U_("unable to allocate memory"));
+			free(digest);
+			debug_return_int(-1);
+		    }
+		    while (isblank((unsigned char)*ep))
+			ep++;
+		    *endptr = (char *)ep;
+		    sudo_debug_printf(SUDO_DEBUG_INFO,
+			"%s digest %s for %s",
+			digest_type_to_name(digest_type),
+			digest->digest_str, cp);
+		    TAILQ_INSERT_TAIL(digests, digest, entries);
+		    debug_return_int(1);
+		}
+	    }
+	}
+    }
+    debug_return_int(0);
+}
+
+/*
+ * If a digest list is present, fill in struct command_digest_list
+ * and update cmnd to point to the command after the digest.
+ * Returns false on error, else true.
+ */
+static bool
+sudo_ldap_extract_digests(char **cmnd, struct command_digest_list *digests)
+{
+    char *cp = *cmnd;
+    int rc;
+    debug_decl(sudo_ldap_extract_digests, SUDOERS_DEBUG_LDAP);
+
+    for (;;) {
+	rc = sudo_ldap_extract_digest(cp, &cp, digests);
+	if (rc != 1)
+	    break;
+
+	/* Check for additional digestspecs, separated by a comma. */
+	if (*cp != ',')
+	    break;
+	do {
+	    cp++;
+	} while (isblank((unsigned char)*cp));
+    }
+    *cmnd = cp;
+
+    debug_return_bool(rc != -1);
+}
+
+/*
+ * Convert an LDAP sudoRole to a sudoers privilege.
+ * Pass in struct berval ** for LDAP or char *** for SSSD.
+ */
+struct privilege *
+sudo_ldap_role_to_priv(const char *cn, void *hosts, void *runasusers,
+    void *runasgroups, void *cmnds, void *opts, const char *notbefore,
+    const char *notafter, bool warnings, bool store_options,
+    sudo_ldap_iter_t iter)
+{
+    struct cmndspec_list negated_cmnds = TAILQ_HEAD_INITIALIZER(negated_cmnds);
+    struct member_list negated_hosts = TAILQ_HEAD_INITIALIZER(negated_hosts);
+    struct cmndspec *prev_cmndspec = NULL;
+    struct privilege *priv;
+    struct member *m;
+    char *cmnd;
+    debug_decl(sudo_ldap_role_to_priv, SUDOERS_DEBUG_LDAP);
+
+    if ((priv = calloc(1, sizeof(*priv))) == NULL)
+	goto oom;
+    TAILQ_INIT(&priv->hostlist);
+    TAILQ_INIT(&priv->cmndlist);
+    TAILQ_INIT(&priv->defaults);
+
+    priv->ldap_role = strdup(cn ? cn : "UNKNOWN");
+    if (priv->ldap_role == NULL)
+	goto oom;
+
+    if (hosts == NULL) {
+	/* The host has already matched, use ALL as wildcard. */
+	if ((m = sudo_ldap_new_member_all()) == NULL)
+	    goto oom;
+	TAILQ_INSERT_TAIL(&priv->hostlist, m, entries);
+    } else {
+	char *host;
+	while ((host = iter(&hosts)) != NULL) {
+	    if ((m = host_to_member(host)) == NULL)
+		goto oom;
+	    if (m->negated)
+		TAILQ_INSERT_TAIL(&negated_hosts, m, entries);
+	    else
+		TAILQ_INSERT_TAIL(&priv->hostlist, m, entries);
+	}
+	/* Negated hosts take precedence so we insert them at the end. */
+	TAILQ_CONCAT(&priv->hostlist, &negated_hosts, entries);
+    }
+
+    /*
+     * Parse sudoCommands and add to cmndlist.
+     */
+    while ((cmnd = iter(&cmnds)) != NULL) {
+	bool negated = sudo_ldap_is_negated(&cmnd);
+	struct sudo_command *c = NULL;
+	struct cmndspec *cmndspec;
+
+	/* Allocate storage upfront. */
+	if ((cmndspec = calloc(1, sizeof(*cmndspec))) == NULL)
+	    goto oom;
+	if ((m = calloc(1, sizeof(*m))) == NULL) {
+	    free(cmndspec);
+	    goto oom;
+	}
+	if ((c = calloc(1, sizeof(*c))) == NULL) {
+	    free(cmndspec);
+	    free(m);
+	    goto oom;
+	}
+	m->name = (char *)c;
+	TAILQ_INIT(&c->digests);
+
+	/* Negated commands have precedence so insert them at the end. */
+	if (negated)
+	    TAILQ_INSERT_TAIL(&negated_cmnds, cmndspec, entries);
+	else
+	    TAILQ_INSERT_TAIL(&priv->cmndlist, cmndspec, entries);
+
+	/* Initialize cmndspec */
+	TAGS_INIT(&cmndspec->tags);
+	cmndspec->notbefore = UNSPEC;
+	cmndspec->notafter = UNSPEC;
+	cmndspec->timeout = UNSPEC;
+	cmndspec->cmnd = m;
+
+	if (prev_cmndspec != NULL) {
+	    /* Inherit values from prior cmndspec (common to the sudoRole). */
+	    cmndspec->runasuserlist = prev_cmndspec->runasuserlist;
+	    cmndspec->runasgrouplist = prev_cmndspec->runasgrouplist;
+	    cmndspec->notbefore = prev_cmndspec->notbefore;
+	    cmndspec->notafter = prev_cmndspec->notafter;
+	    cmndspec->timeout = prev_cmndspec->timeout;
+	    cmndspec->runchroot = prev_cmndspec->runchroot;
+	    cmndspec->runcwd = prev_cmndspec->runcwd;
+#ifdef HAVE_SELINUX
+	    cmndspec->role = prev_cmndspec->role;
+	    cmndspec->type = prev_cmndspec->type;
+#endif /* HAVE_SELINUX */
+#ifdef HAVE_PRIV_SET
+	    cmndspec->privs = prev_cmndspec->privs;
+	    cmndspec->limitprivs = prev_cmndspec->limitprivs;
+#endif /* HAVE_PRIV_SET */
+	    cmndspec->tags = prev_cmndspec->tags;
+	    if (cmndspec->tags.setenv == IMPLIED)
+		cmndspec->tags.setenv = UNSPEC;
+	} else {
+	    /* Parse sudoRunAsUser / sudoRunAs */
+	    if (runasusers != NULL) {
+		cmndspec->runasuserlist =
+		    array_to_member_list(runasusers, iter);
+		if (cmndspec->runasuserlist == NULL)
+		    goto oom;
+	    }
+
+	    /* Parse sudoRunAsGroup */
+	    if (runasgroups != NULL) {
+		cmndspec->runasgrouplist =
+		    array_to_member_list(runasgroups, iter);
+		if (cmndspec->runasgrouplist == NULL)
+		    goto oom;
+	    }
+
+	    /* Parse sudoNotBefore / sudoNotAfter */
+	    if (notbefore != NULL)
+		cmndspec->notbefore = parse_gentime(notbefore);
+	    if (notafter != NULL)
+		cmndspec->notafter = parse_gentime(notafter);
+
+	    /* Parse sudoOptions. */
+	    if (opts != NULL) {
+		char *opt, *source = NULL;
+
+		if (store_options) {
+		    /* Use sudoRole in place of file name in defaults. */
+		    size_t slen = sizeof("sudoRole ") - 1 + strlen(priv->ldap_role);
+		    if ((source = sudo_rcstr_alloc(slen)) == NULL)
+			goto oom;
+		    if ((size_t)snprintf(source, slen + 1, "sudoRole %s", priv->ldap_role) != slen) {
+			sudo_warnx(U_("internal error, %s overflow"), __func__);
+			sudo_rcstr_delref(source);
+			goto bad;
+		    }
+		}
+
+		while ((opt = iter(&opts)) != NULL) {
+		    char *var, *val;
+		    int op;
+
+		    op = sudo_ldap_parse_option(opt, &var, &val);
+		    if (strcmp(var, "command_timeout") == 0 && val != NULL) {
+			if (cmndspec->timeout != UNSPEC) {
+			    sudo_warnx(U_("duplicate sudoOption: %s%s%s"), var,
+				op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+			}
+			cmndspec->timeout = parse_timeout(val);
+		    } else if (strcmp(var, "runchroot") == 0 && val != NULL) {
+			if (cmndspec->runchroot != NULL) {
+			    free(cmndspec->runchroot);
+			    sudo_warnx(U_("duplicate sudoOption: %s%s%s"), var,
+				op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+			}
+			if ((cmndspec->runchroot = strdup(val)) == NULL)
+			    break;
+		    } else if (strcmp(var, "runcwd") == 0 && val != NULL) {
+			if (cmndspec->runcwd != NULL) {
+			    free(cmndspec->runcwd);
+			    sudo_warnx(U_("duplicate sudoOption: %s%s%s"), var,
+				op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+			}
+			if ((cmndspec->runcwd = strdup(val)) == NULL)
+			    break;
+#ifdef HAVE_SELINUX
+		    } else if (strcmp(var, "role") == 0 && val != NULL) {
+			if (cmndspec->role != NULL) {
+			    free(cmndspec->role);
+			    sudo_warnx(U_("duplicate sudoOption: %s%s%s"), var,
+				op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+			}
+			if ((cmndspec->role = strdup(val)) == NULL)
+			    break;
+		    } else if (strcmp(var, "type") == 0 && val != NULL) {
+			if (cmndspec->type != NULL) {
+			    free(cmndspec->type);
+			    sudo_warnx(U_("duplicate sudoOption: %s%s%s"), var,
+				op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+			}
+			if ((cmndspec->type = strdup(val)) == NULL)
+			    break;
+#endif /* HAVE_SELINUX */
+#ifdef HAVE_PRIV_SET
+		    } else if (strcmp(var, "privs") == 0 && val != NULL) {
+			if (cmndspec->privs != NULL) {
+			    free(cmndspec->privs);
+			    sudo_warnx(U_("duplicate sudoOption: %s%s%s"), var,
+				op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+			}
+			if ((cmndspec->privs = strdup(val)) == NULL)
+			    break;
+		    } else if (strcmp(var, "limitprivs") == 0 && val != NULL) {
+			if (cmndspec->limitprivs != NULL) {
+			    free(cmndspec->limitprivs);
+			    sudo_warnx(U_("duplicate sudoOption: %s%s%s"), var,
+				op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+			}
+			if ((cmndspec->limitprivs = strdup(val)) == NULL)
+			    break;
+#endif /* HAVE_PRIV_SET */
+		    } else if (store_options) {
+			if (!append_default(var, val, op, source,
+			    &priv->defaults)) {
+			    break;
+			}
+		    } else {
+			/* Convert to tags. */
+			bool converted = sudoers_defaults_to_tags(var, val, op,
+			    &cmndspec->tags);
+			if (!converted) {
+			    if (warnings) {
+				/* XXX - callback to process unsupported options. */
+				if (val != NULL) {
+				    sudo_warnx(U_("unable to convert sudoOption: %s%s%s"), var, op == '+' ? "+=" : op == '-' ? "-=" : "=", val);
+				} else {
+				    sudo_warnx(U_("unable to convert sudoOption: %s%s%s"), op == false ? "!" : "", var, "");
+				}
+			    }
+			    continue;
+			}
+		    }
+		}
+		sudo_rcstr_delref(source);
+		if (opt != NULL) {
+		    /* Defer oom until we drop the ref on source. */
+		    goto oom;
+		}
+	    }
+
+	    /* So we can inherit previous values. */
+	    prev_cmndspec = cmndspec;
+	}
+
+	/* Fill in command member now that options have been processed. */
+	m->negated = negated;
+	if (!sudo_ldap_extract_digests(&cmnd, &c->digests))
+	    goto oom;
+	if (strcmp(cmnd, "ALL") == 0) {
+	    if (cmndspec->tags.setenv == UNSPEC)
+		cmndspec->tags.setenv = IMPLIED;
+	    m->type = ALL;
+	} else {
+	    char *args = strpbrk(cmnd, " \t");
+	    if (args != NULL) {
+		*args++ = '\0';
+		if ((c->args = strdup(args)) == NULL)
+		    goto oom;
+	    }
+	    if ((c->cmnd = strdup(cmnd)) == NULL)
+		goto oom;
+	    m->type = COMMAND;
+	}
+    }
+    /* Negated commands take precedence so we insert them at the end. */
+    TAILQ_CONCAT(&priv->cmndlist, &negated_cmnds, entries);
+
+    debug_return_ptr(priv);
+
+oom:
+    sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+bad:
+    if (priv != NULL) {
+	TAILQ_CONCAT(&priv->hostlist, &negated_hosts, entries);
+	TAILQ_CONCAT(&priv->cmndlist, &negated_cmnds, entries);
+	free_privilege(priv);
+    }
+    debug_return_ptr(NULL);
+}
+
+/* So ldap.c and sssd.c don't need to include gram.h */
+struct member *
+sudo_ldap_new_member_all(void)
+{
+    struct member *m;
+    debug_decl(sudo_ldap_new_member_all, SUDOERS_DEBUG_LDAP);
+
+    if ((m = calloc(1, sizeof(*m))) != NULL)
+	m->type = ALL;
+    debug_return_ptr(m);
+}
+
+/*
+ * Determine length of query value after escaping characters
+ * as per RFC 4515.
+ */
+size_t
+sudo_ldap_value_len(const char *value)
+{
+    const char *s;
+    size_t len = 0;
+
+    for (s = value; *s != '\0'; s++) {
+	switch (*s) {
+	case '\\':
+	case '(':
+	case ')':
+	case '*':
+	    len += 2;
+	    break;
+	}
+    }
+    len += (size_t)(s - value);
+    return len;
+}
+
+/*
+ * Like strlcat() but escapes characters as per RFC 4515.
+ */
+size_t
+sudo_ldap_value_cat(char * restrict dst, const char * restrict src, size_t size)
+{
+    char *d = dst;
+    const char *s = src;
+    size_t n = size;
+    size_t dlen;
+
+    /* Find the end of dst and adjust bytes left but don't go past end */
+    while (n-- != 0 && *d != '\0')
+	d++;
+    dlen = (size_t)(d - dst);
+    n = size - dlen;
+
+    if (n == 0)
+	return dlen + strlen(s);
+    while (*s != '\0') {
+	switch (*s) {
+	case '\\':
+	    if (n < 3)
+		goto done;
+	    *d++ = '\\';
+	    *d++ = '5';
+	    *d++ = 'c';
+	    n -= 3;
+	    break;
+	case '(':
+	    if (n < 3)
+		goto done;
+	    *d++ = '\\';
+	    *d++ = '2';
+	    *d++ = '8';
+	    n -= 3;
+	    break;
+	case ')':
+	    if (n < 3)
+		goto done;
+	    *d++ = '\\';
+	    *d++ = '2';
+	    *d++ = '9';
+	    n -= 3;
+	    break;
+	case '*':
+	    if (n < 3)
+		goto done;
+	    *d++ = '\\';
+	    *d++ = '2';
+	    *d++ = 'a';
+	    n -= 3;
+	    break;
+	default:
+	    if (n < 1)
+		goto done;
+	    *d++ = *s;
+	    n--;
+	    break;
+	}
+	s++;
+    }
+done:
+    *d = '\0';
+    while (*s != '\0')
+	s++;
+    return dlen + (size_t)(s - src);	/* count does not include NUL */
+}
+
+/*
+ * Like strdup() but escapes characters as per RFC 4515.
+ */
+char *
+sudo_ldap_value_dup(const char *src)
+{
+    char *dst;
+    size_t size;
+
+    size = sudo_ldap_value_len(src) + 1;
+    dst = malloc(size);
+    if (dst == NULL)
+	return NULL;
+
+    *dst = '\0';
+    if (sudo_ldap_value_cat(dst, src, size) >= size) {
+	/* Should not be possible... */
+	free(dst);
+	dst = NULL;
+    }
+    return dst;
+}