/*
* Copyright (c) 1993-1996,1998-2005, 2007-2013
* Todd C. Miller <Todd.Miller@courtesan.com>
*
* 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.
*/
#include <config.h>
#include <sys/types.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <pwd.h>
#include <grp.h>
#include "sudoers.h"
/*
* Expand %h and %u escapes in the prompt and pass back the dynamically
* allocated result. Returns the same string if there are no escapes.
*/
char *
expand_prompt(const char *old_prompt, const char *user, const char *host)
{
size_t len, n;
int subst;
const char *p;
char *np, *new_prompt, *endp;
debug_decl(expand_prompt, SUDO_DEBUG_AUTH)
/* How much space do we need to malloc for the prompt? */
subst = 0;
for (p = old_prompt, len = strlen(old_prompt); *p; p++) {
if (p[0] =='%') {
switch (p[1]) {
case 'h':
p++;
len += strlen(user_shost) - 2;
subst = 1;
break;
case 'H':
p++;
len += strlen(user_host) - 2;
subst = 1;
break;
case 'p':
p++;
if (def_rootpw)
len += 2;
else if (def_targetpw || def_runaspw)
len += strlen(runas_pw->pw_name) - 2;
else
len += strlen(user_name) - 2;
subst = 1;
break;
case 'u':
p++;
len += strlen(user_name) - 2;
subst = 1;
break;
case 'U':
p++;
len += strlen(runas_pw->pw_name) - 2;
subst = 1;
break;
case '%':
p++;
len--;
subst = 1;
break;
default:
break;
}
}
}
if (subst) {
new_prompt = emalloc(++len);
endp = new_prompt + len;
for (p = old_prompt, np = new_prompt; *p; p++) {
if (p[0] =='%') {
switch (p[1]) {
case 'h':
p++;
n = strlcpy(np, user_shost, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case 'H':
p++;
n = strlcpy(np, user_host, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case 'p':
p++;
if (def_rootpw)
n = strlcpy(np, "root", np - endp);
else if (def_targetpw || def_runaspw)
n = strlcpy(np, runas_pw->pw_name, np - endp);
else
n = strlcpy(np, user_name, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case 'u':
p++;
n = strlcpy(np, user_name, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case 'U':
p++;
n = strlcpy(np, runas_pw->pw_name, np - endp);
if (n >= np - endp)
goto oflow;
np += n;
continue;
case '%':
/* convert %% -> % */
p++;
break;
default:
/* no conversion */
break;
}
}
*np++ = *p;
if (np >= endp)
goto oflow;
}
*np = '\0';
} else
new_prompt = estrdup(old_prompt);
debug_return_str(new_prompt);
oflow:
/* We pre-allocate enough space, so this should never happen. */
fatalx(_("internal error, %s overflow"), "expand_prompt()");
}
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