| [9] | 1 | /* crypt() - one-way password encryption function Author: Kees J. Bot
|
|---|
| 2 | * 7 Feb 1994
|
|---|
| 3 | * This routine does not encrypt anything, it uses the pwdauth
|
|---|
| 4 | * program to do the hard work.
|
|---|
| 5 | */
|
|---|
| 6 | #define nil ((void*)0)
|
|---|
| 7 | #define pipe _pipe
|
|---|
| 8 | #define fork _fork
|
|---|
| 9 | #define close _close
|
|---|
| 10 | #define dup2 _dup2
|
|---|
| 11 | #define execl _execl
|
|---|
| 12 | #define read _read
|
|---|
| 13 | #define _exit __exit
|
|---|
| 14 | #define write _write
|
|---|
| 15 | #define waitpid _waitpid
|
|---|
| 16 | #include <sys/types.h>
|
|---|
| 17 | #include <unistd.h>
|
|---|
| 18 | #include <string.h>
|
|---|
| 19 | #include <stdio.h>
|
|---|
| 20 | #include <errno.h>
|
|---|
| 21 | #include <stdarg.h>
|
|---|
| 22 | #include <sys/wait.h>
|
|---|
| 23 |
|
|---|
| 24 | /* Set-uid root program to read /etc/shadow or encrypt passwords. */
|
|---|
| 25 | static char PWDAUTH[] = "/usr/lib/pwdauth";
|
|---|
| 26 | #define LEN 1024
|
|---|
| 27 |
|
|---|
| 28 | static void tell(const char *s0, ...)
|
|---|
| 29 | {
|
|---|
| 30 | va_list ap;
|
|---|
| 31 | const char *s;
|
|---|
| 32 |
|
|---|
| 33 | va_start(ap, s0);
|
|---|
| 34 | s= s0;
|
|---|
| 35 | while (s != nil) {
|
|---|
| 36 | (void) write(2, s, strlen(s));
|
|---|
| 37 | s= va_arg(ap, const char *);
|
|---|
| 38 | }
|
|---|
| 39 | va_end(ap);
|
|---|
| 40 | }
|
|---|
| 41 |
|
|---|
| 42 | char *crypt(const char *key, const char *salt)
|
|---|
| 43 | {
|
|---|
| 44 | pid_t pid;
|
|---|
| 45 | int status;
|
|---|
| 46 | int pfd[2];
|
|---|
| 47 | static char pwdata[LEN];
|
|---|
| 48 | char *p= pwdata;
|
|---|
| 49 | const char *k= key;
|
|---|
| 50 | const char *s= salt;
|
|---|
| 51 | int n;
|
|---|
| 52 |
|
|---|
| 53 | /* Fill pwdata[] with the key and salt. */
|
|---|
| 54 | while ((*p++ = *k++) != 0) if (p == pwdata+LEN-1) goto fail;
|
|---|
| 55 | while ((*p++ = *s++) != 0) if (p == pwdata+LEN-0) goto fail;
|
|---|
| 56 |
|
|---|
| 57 | if (pipe(pfd) < 0) goto fail;
|
|---|
| 58 |
|
|---|
| 59 | /* Prefill the pipe. */
|
|---|
| 60 | (void) write(pfd[1], pwdata, p - pwdata);
|
|---|
| 61 |
|
|---|
| 62 | switch ((pid= fork())) {
|
|---|
| 63 | case -1:
|
|---|
| 64 | close(pfd[0]);
|
|---|
| 65 | close(pfd[1]);
|
|---|
| 66 | goto fail;
|
|---|
| 67 | case 0:
|
|---|
| 68 | /* Connect both input and output to the pipe. */
|
|---|
| 69 | if (pfd[0] != 0) {
|
|---|
| 70 | dup2(pfd[0], 0);
|
|---|
| 71 | close(pfd[0]);
|
|---|
| 72 | }
|
|---|
| 73 | if (pfd[1] != 1) {
|
|---|
| 74 | dup2(pfd[1], 1);
|
|---|
| 75 | close(pfd[1]);
|
|---|
| 76 | }
|
|---|
| 77 |
|
|---|
| 78 | execl(PWDAUTH, PWDAUTH, (char *) nil);
|
|---|
| 79 |
|
|---|
| 80 | tell("crypt(): ", PWDAUTH, ": ", strerror(errno), "\r\n",
|
|---|
| 81 | (char *) nil);
|
|---|
| 82 | /* No pwdauth? Fail! */
|
|---|
| 83 | (void) read(0, pwdata, LEN);
|
|---|
| 84 | _exit(1);
|
|---|
| 85 | }
|
|---|
| 86 | close(pfd[1]);
|
|---|
| 87 |
|
|---|
| 88 | status= -1;
|
|---|
| 89 | while (waitpid(pid, &status, 0) == -1 && errno == EINTR) {}
|
|---|
| 90 | if (status != 0) {
|
|---|
| 91 | close(pfd[0]);
|
|---|
| 92 | goto fail;
|
|---|
| 93 | }
|
|---|
| 94 |
|
|---|
| 95 | /* Read and return the result. Check if it contains exactly one
|
|---|
| 96 | * string.
|
|---|
| 97 | */
|
|---|
| 98 | n= read(pfd[0], pwdata, LEN);
|
|---|
| 99 | close(pfd[0]);
|
|---|
| 100 | if (n < 0) goto fail;
|
|---|
| 101 | p = pwdata + n;
|
|---|
| 102 | n = 0;
|
|---|
| 103 | while (p > pwdata) if (*--p == 0) n++;
|
|---|
| 104 | if (n != 1) goto fail;
|
|---|
| 105 | return pwdata;
|
|---|
| 106 |
|
|---|
| 107 | fail:
|
|---|
| 108 | pwdata[0] = salt[0] ^ 1; /* make result != salt */
|
|---|
| 109 | pwdata[1] = 0;
|
|---|
| 110 | return pwdata;
|
|---|
| 111 | }
|
|---|
| 112 |
|
|---|
| 113 | /*
|
|---|
| 114 | * $PchId: crypt.c,v 1.5 1996/04/11 07:46:11 philip Exp $
|
|---|
| 115 | */
|
|---|
