/* crypt() - one-way password encryption function Author: Kees J. Bot * 7 Feb 1994 * This routine does not encrypt anything, it uses the pwdauth * program to do the hard work. */ #define nil 0 #define pipe _pipe #define fork _fork #define close _close #define dup2 _dup2 #define execl _execl #define read _read #define _exit __exit #define write _write #define waitpid _waitpid #include <sys/types.h> #include <unistd.h> #include <string.h> #include <stdio.h> #include <sys/wait.h> /* Set-uid root program to read /etc/shadow or encrypt passwords. */ static char PWDAUTH[] = "/usr/lib/pwdauth"; #define LEN 1024 char *crypt(const char *key, const char *salt) { pid_t pid; int status; int pfd[2]; static char pwdata[LEN]; char *p= pwdata; const char *k= key; const char *s= salt; int n; /* Fill pwdata[] with the key and salt. */ while ((*p++ = *k++) != 0) if (p == pwdata+LEN-1) goto fail; while ((*p++ = *s++) != 0) if (p == pwdata+LEN-0) goto fail; if (pipe(pfd) < 0) goto fail; /* Prefill the pipe. */ (void) write(pfd[1], pwdata, p - pwdata); switch ((pid= fork())) { case -1: close(pfd[0]); close(pfd[1]); goto fail; case 0: /* Connect both input and output to the pipe. */ if (pfd[0] != 0) { dup2(pfd[0], 0); close(pfd[0]); } if (pfd[1] != 1) { dup2(pfd[1], 1); close(pfd[1]); } execl(PWDAUTH, PWDAUTH, (char *) nil); /* No pwdauth? Fail! */ (void) read(0, pwdata, LEN); _exit(1); } close(pfd[1]); if (waitpid(pid, &status, 0) < 0 || status != 0) { close(pfd[0]); goto fail; } /* Read and return the result. Check if it contains exactly one * string. */ n= read(pfd[0], pwdata, LEN); close(pfd[0]); if (n < 0) goto fail; p = pwdata + n; n = 0; while (p > pwdata) if (*--p == 0) n++; if (n != 1) goto fail; return pwdata; fail: pwdata[0] = salt[0] ^ 1; /* make result != salt */ pwdata[1] = 0; return pwdata; } /* * $PchHeader: /mount/hd2/minix/lib/misc/RCS/crypt.c,v 1.3 1994/12/22 13:51:49 philip Exp $ */