2 * Copyright (c) 2011 Dag-Erling Smørgrav
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote
14 * products derived from this software without specific prior written
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * $OpenPAM: openpam_subst.c 938 2017-04-30 21:34:42Z des $
36 #include <security/pam_appl.h>
38 #include "openpam_impl.h"
40 #define subst_char(ch) do { \
42 if (buf && len < *bufsize) \
47 #define subst_string(s) do { \
48 const char *s_ = (s); \
53 #define subst_item(i) do { \
56 ret = pam_get_item(pamh, i_, &p_); \
57 if (ret == PAM_SUCCESS && p_ != NULL) \
64 * Substitute PAM item values in a string
68 openpam_subst(const pam_handle_t *pamh,
69 char *buf, size_t *bufsize, const char *template)
78 len = 1; /* initialize to 1 for terminating NUL */
80 while (*template && ret == PAM_SUCCESS) {
81 if (template[0] == '%') {
85 subst_item(PAM_SERVICE);
97 subst_item(PAM_RHOST);
100 subst_item(PAM_RUSER);
107 subst_char(*template);
111 subst_char(*template++);
116 if (ret == PAM_SUCCESS) {
133 * The =openpam_subst function expands a string, substituting PAM item
134 * values for all occurrences of specific substitution codes.
135 * The =template argument points to the initial string.
136 * The result is stored in the buffer pointed to by the =buf argument; the
137 * =bufsize argument specifies the size of that buffer.
138 * The actual size of the resulting string, including the terminating NUL
139 * character, is stored in the location pointed to by the =bufsize
142 * If =buf is NULL, or if the buffer is too small to hold the expanded
143 * string, =bufsize is updated to reflect the amount of space required to
144 * hold the entire string, and =openpam_subst returns =PAM_TRY_AGAIN.
146 * If =openpam_subst fails for any other reason, the =bufsize argument is
147 * untouched, but part of the buffer may still have been overwritten.
149 * Substitution codes are introduced by a percent character and correspond
153 * Replaced by the current value of the =PAM_RHOST item.
155 * Replaced by the current value of the =PAM_HOST item.
157 * Replaced by the current value of the =PAM_SERVICE item.
159 * Replaced by the current value of the =PAM_TTY item.
161 * Replaced by the current value of the =PAM_RUSER item.
163 * Replaced by the current value of the =PAM_USER item.