From d0f7935f637df5d4794aa782def96cc3db8779ed Mon Sep 17 00:00:00 2001
From: Rob Landley <rob@landley.net>
Date: Wed, 16 Oct 2013 19:30:17 -0500
Subject: Prep work for useradd by Ashwini Sharma.

---
 toys/lsb/passwd.c | 113 ++++++++++++------------------------------------------
 1 file changed, 25 insertions(+), 88 deletions(-)

(limited to 'toys')

diff --git a/toys/lsb/passwd.c b/toys/lsb/passwd.c
index 167d5730..1784c049 100644
--- a/toys/lsb/passwd.c
+++ b/toys/lsb/passwd.c
@@ -11,9 +11,9 @@ config PASSWD
   bool "passwd"
   default y
   help
-    usage: passwd [-a ALGO] [-d] [-l] [-u] <account name>
+    usage: passwd [-a ALGO] [-dlu] <account name>
 
-    update user’s authentication tokens. Default : current user
+    update user's authentication tokens. Default : current user
 
     -a ALGO	Encryption method (des, md5, sha256, sha512) default: des
     -d		Set password to ''
@@ -23,81 +23,25 @@ config PASSWD
 
 #define FOR_passwd
 #include "toys.h"
-#include <time.h>
 
 GLOBALS(
   char *algo;
 )
 
-#define MAX_SALT_LEN  20 //3 for id, 16 for key, 1 for '\0'
-#define URANDOM_PATH    "/dev/urandom"
-
 #ifndef _GNU_SOURCE
 char *strcasestr(const char *haystack, const char *needle);
 #endif
 
-unsigned int random_number_generator(int fd)
-{
-  unsigned int randnum;
-
-  xreadall(fd, &randnum, sizeof(randnum));
-  return randnum;
-}
-
-char inttoc(int i)
-{
-  // salt value uses 64 chracters in "./0-9a-zA-Z"
-  const char character_set[]="./0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
-
-  i &= 0x3f; // masking for using 10 bits only
-  return character_set[i];
-}
-
-int get_salt(char *salt)
-{
-  int i, salt_length = 0;
-  int randfd;
-
-  if (!strncmp(TT.algo,"des",3)) {
-    // 2 bytes salt value is used in des
-    salt_length = 2;
-  } else {
-    *salt++ = '$';
-    if (!strncmp(TT.algo,"md5",3)) {
-      *salt++ = '1';
-      // 8 bytes salt value is used in md5
-      salt_length = 8;
-    } else if (!strncmp(TT.algo,"sha256",6)) {
-      *salt++ = '5';
-      // 16 bytes salt value is used in sha256
-      salt_length = 16;
-    } else if (!strncmp(TT.algo,"sha512",6)) {
-      *salt++ = '6';
-      // 16 bytes salt value is used in sha512
-      salt_length = 16;
-    } else return 1;
-
-    *salt++ = '$';
-  }
-
-  randfd = xopen(URANDOM_PATH, O_RDONLY);
-  for (i=0; i<salt_length; i++)
-    salt[i] = inttoc(random_number_generator(randfd));
-  salt[salt_length+1] = '\0';
-  xclose(randfd);
-
-  return 0;
-}
-
 static int str_check(char *s, char *p)
 {
-  if ((strcasestr(s, p) != NULL) || (strcasestr(p, s) != NULL)) return 1;
+  if (strcasestr(s, p) || strcasestr(p, s)) return 1;
   return 0;
 }
 
 static void strength_check(char *newp, char *oldp, char *user)
 {
   char *msg = NULL;
+
   if (strlen(newp) < 6) { //Min passwd len
     msg = "too short";
     xprintf("BAD PASSWORD: %s\n",msg);
@@ -123,7 +67,7 @@ static int verify_passwd(char * pwd)
   if (pwd[0] == '!' || pwd[0] == '*') return 1;
 
   pass = crypt(toybuf, pwd);
-  if (pass != NULL && strcmp(pass, pwd)==0) return 0;
+  if (pass  && !strcmp(pass, pwd)) return 0;
 
   return 1;
 }
@@ -142,32 +86,27 @@ static char *new_password(char *oldp, char *user)
     return NULL; //may be due to Ctrl-C
   }
 
-  if (strcmp(newp, toybuf) == 0) return newp;
+  if (!strcmp(newp, toybuf)) return newp;
   else error_msg("Passwords do not match.\n");
-  /*Failure Case */
+  // Failure Case
   free(newp);
-
   return NULL;
 }
 
-
 void passwd_main(void)
 {
   uid_t myuid;
   struct passwd *pw;
   struct spwd *sp;
-  char *name = NULL;
-  char *pass = NULL, *encrypted = NULL, *newp = NULL;
-  char *orig = (char *)"";
-  char salt[MAX_SALT_LEN];
+  char *name = NULL, *pass = NULL, *encrypted = NULL, *newp = NULL,
+       *orig = (char *)"", salt[MAX_SALT_LEN];
   int ret = -1;
 
   myuid = getuid();
-  if ((myuid != 0) && (toys.optflags & (FLAG_l | FLAG_u | FLAG_d)))
+  if ((myuid) && (toys.optflags & (FLAG_l | FLAG_u | FLAG_d)))
     error_exit("You need to be root to do these actions\n");
 
   pw = getpwuid(myuid);
-
   if (!pw) error_exit("Unknown uid '%u'",myuid);
 
   if (toys.optargs[0]) name = toys.optargs[0];
@@ -176,23 +115,28 @@ void passwd_main(void)
   pw = getpwnam(name);
   if (!pw) error_exit("Unknown user '%s'",name);
 
-  if (myuid != 0 && (myuid != pw->pw_uid))
+  if (myuid && (myuid != pw->pw_uid))
     error_exit("You need to be root to change '%s' password\n", name);
 
   pass = pw->pw_passwd;
   if (pw->pw_passwd[0] == 'x') {
-    /*get shadow passwd */
+    //get shadow passwd
     sp = getspnam(name);
     if (sp) pass = sp->sp_pwdp;
   }
 
 
   if (!(toys.optflags & (FLAG_l | FLAG_u | FLAG_d))) {
+    
+    if (!(toys.optflags & FLAG_a)) TT.algo = "des";
+    if (get_salt(salt, TT.algo) == -1)
+      error_exit("Error: Unkown encryption algorithm\n");
+
     printf("Changing password for %s\n",name);
-    if (pass[0] == '!')
+    if (myuid && pass[0] == '!')
       error_exit("Can't change, password is locked for %s",name);
-    if (myuid != 0) {
-      /*Validate user */
+    if (myuid) {
+      //Validate user 
 
       if (read_password(toybuf, sizeof(toybuf), "Origial password:")) {
         if (!toys.optargs[0]) free(name);
@@ -204,7 +148,7 @@ void passwd_main(void)
 
     orig = xstrdup(orig);
 
-    /*Get new password */
+    // Get new password
     newp = new_password(orig, name);
     if (!newp) {
       free(orig);
@@ -212,31 +156,24 @@ void passwd_main(void)
       return; //new password is not set well.
     }
 
-    /*Encrypt the passwd */
-    if (!(toys.optflags & FLAG_a)) TT.algo = "des";
-
-    if (get_salt(salt)) error_exit("Error: Unkown encryption algorithm\n");
-
     encrypted = crypt(newp, salt);
     free(newp);
     free(orig);
   } else if (toys.optflags & FLAG_l) {
-    if (pass[0] == '!')
-      error_exit("password is already locked for %s",name);
+    if (pass[0] == '!') error_exit("password is already locked for %s",name);
     printf("Locking password for %s\n",name);
     encrypted = xmsprintf("!%s",pass);
   } else if (toys.optflags & FLAG_u) {
-    if (pass[0] != '!')
-      error_exit("password is already unlocked for %s",name);
+    if (pass[0] != '!') error_exit("password is already unlocked for %s",name);
 
     printf("Unlocking password for %s\n",name);
     encrypted = xstrdup(&pass[1]);
   } else if (toys.optflags & FLAG_d) {
     printf("Deleting password for %s\n",name);
-    encrypted = (char*)xzalloc(sizeof(char)*2); //1 = "", 2 = '\0'
+    encrypted = xstrdup(""); //1 = "", 2 = '\0'
   }
 
-  /*Update the passwd */
+  // Update the passwd
   if (pw->pw_passwd[0] == 'x')
     ret = update_password("/etc/shadow", name, encrypted);
   else ret = update_password("/etc/passwd", name, encrypted);
-- 
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