/*- * Copyright (c) 2011-2023 Dag-Erling Smørgrav * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include "openpam_impl.h" #define subst_char(ch) do { \ int ch_ = (ch); \ if (buf && len < *bufsize) \ *buf++ = ch_; \ ++len; \ } while (0) #define subst_string(s) do { \ const char *s_ = (s); \ while (*s_) \ subst_char(*s_++); \ } while (0) #define subst_item(i) do { \ int i_ = (i); \ const void *p_; \ ret = pam_get_item(pamh, i_, &p_); \ if (ret == PAM_SUCCESS && p_ != NULL) \ subst_string(p_); \ } while (0) /* * OpenPAM internal * * Substitute PAM item values in a string */ int openpam_subst(const pam_handle_t *pamh, char *buf, size_t *bufsize, const char *template) { size_t len; int ret; ENTERS(template); if (template == NULL) template = "(null)"; len = 1; /* initialize to 1 for terminating NUL */ ret = PAM_SUCCESS; while (*template && ret == PAM_SUCCESS) { if (template[0] == '%') { ++template; switch (*template) { case 's': subst_item(PAM_SERVICE); break; case 't': subst_item(PAM_TTY); break; case 'h': subst_item(PAM_HOST); break; case 'u': subst_item(PAM_USER); break; case 'H': subst_item(PAM_RHOST); break; case 'U': subst_item(PAM_RUSER); break; case '\0': subst_char('%'); break; default: subst_char('%'); subst_char(*template); } if (*template) ++template; } else { subst_char(*template++); } } if (buf) *buf = '\0'; if (ret == PAM_SUCCESS) { if (len > *bufsize) ret = PAM_TRY_AGAIN; *bufsize = len; } RETURNC(ret); } /* * Error codes: * * =pam_get_item * !PAM_SYMBOL_ERR * PAM_TRY_AGAIN */ /** * The =openpam_subst function expands a string, substituting PAM item * values for all occurrences of specific substitution codes. * The =template argument points to the initial string. * The result is stored in the buffer pointed to by the =buf argument; the * =bufsize argument specifies the size of that buffer. * The actual size of the resulting string, including the terminating NUL * character, is stored in the location pointed to by the =bufsize * argument. * * If =buf is NULL, or if the buffer is too small to hold the expanded * string, =bufsize is updated to reflect the amount of space required to * hold the entire string, and =openpam_subst returns =PAM_TRY_AGAIN. * * If =openpam_subst fails for any other reason, the =bufsize argument is * untouched, but part of the buffer may still have been overwritten. * * Substitution codes are introduced by a percent character and correspond * to PAM items: * * %H: * Replaced by the current value of the =PAM_RHOST item. * %h: * Replaced by the current value of the =PAM_HOST item. * %s: * Replaced by the current value of the =PAM_SERVICE item. * %t: * Replaced by the current value of the =PAM_TTY item. * %U: * Replaced by the current value of the =PAM_RUSER item. * %u: * Replaced by the current value of the =PAM_USER item. * * >pam_get_authtok * >pam_get_item * >pam_get_user * * AUTHOR DES */