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#include <sys/stat.h>
#include "error.h"
#include "pathexec.h"
#include "prot.h"
#include "stralloc.h"
#include "openreadclose.h"
#include "env.h"
#include "global.h"
#include "md5.h"
#include "auto_maildir.h"
#include "auto_password.h"
#include "auto_patrn.h"
#include <pwd.h>
static struct passwd *pw;
static char up[513];
static int uplen;
static stralloc stored = {0};
static stralloc pwfile = {0};
static char *hextable = "0123456789abcdef";
void cleanup()
{
int i;
for (i = 0;i < sizeof(up);++i) up[i] = 0;
for (i = 0;i < stored.len;++i) stored.s[i] = 0;
}
void die(int x)
{
cleanup();
_exit(x);
}
main(int argc,char **argv)
{
char *login;
char *dash;
char *ext;
char *password;
char *timestamp;
struct stat st;
int r;
int i;
MD5_CTX context;
unsigned char digest[16];
char encrypted[16*2+1];
char *s;
if (!argv[1]) _exit(2);
dash = env_get("DASH");
uplen = 0;
for (;;) {
do
r = read(3,up + uplen,sizeof(up) - uplen);
while ((r == -1) && (errno == error_intr));
if (r == -1) _exit(111);
if (r == 0) break;
uplen += r;
if (uplen >= sizeof(up)) _exit(1);
}
close(3);
i = 0;
if (i >= uplen) _exit(2);
login = up + i;
while (up[i++]) if (i >= uplen) _exit(2);
password = up + i;
if (i >= uplen) _exit(2);
while (up[i++]) if (i >= uplen) _exit(2);
timestamp = up + i;
if (i >= uplen) _exit(2);
while (up[i++]) if (i >= uplen) _exit(2);
i = 0;
ext = login + str_len(login);
for (;;) {
pw = getpwnam(login);
if (pw) break;
if (errno == error_txtbsy) die(111);
for (; ext != login && *ext != '-'; --ext);
if (ext == login) die(1);
if (i) login[i] = '-';
i = ext - login;
login[i] = 0;
++ext;
}
if (chdir(pw->pw_dir) == -1) die(111);
if (!stralloc_copys(&pwfile, auto_maildir)) die(111);
if (dash && *ext) {
if (!stralloc_cats(&pwfile, dash)) die(111);
if (!stralloc_cats(&pwfile, ext)) die(111);
}
if (!stralloc_append(&pwfile, "/")) die(111);
if (!stralloc_cats(&pwfile, auto_password)) die(111);
if (!stralloc_0(&pwfile)) die(111);
if (stat(pwfile.s,&st) == -1) die(1);
if (st.st_uid != pw->pw_uid) die(1);
if (st.st_mode & auto_patrn) die(111);
if (openreadclose(pwfile.s,&stored,32) != 1) die(111);
if (!stralloc_0(&stored)) die(111);
stored.s[str_chr(stored.s,'\n')] = 0;
MD5Init(&context);
MD5Update(&context, timestamp, str_len(timestamp));
MD5Update(&context, stored.s, str_len(stored.s));
MD5Final(digest, &context);
s = encrypted;
for (i = 0; i < sizeof(digest); ++i) {
*s = hextable[digest[i]/16]; ++s;
*s = hextable[digest[i]%16]; ++s;
}
*s = '\0';
if (strcmp(password,encrypted)) die(1);
if (prot_gid((int) pw->pw_gid) == -1) die(1);
if (prot_uid((int) pw->pw_uid) == -1) die(1);
if (!pathexec_env("USER",pw->pw_name)) die(111);
if (!pathexec_env("EXT",ext)) die(111);
if (!pathexec_env("HOME",pw->pw_dir)) die(111);
if (!pathexec_env("SHELL",pw->pw_shell)) die(111);
cleanup();
pathexec(argv + 1);
_exit(111);
}
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