[PATCH] chpasswd: support -c argument and respect DEFAULT_PASSWD_ALGO

[Tito]

On 12/18/2015 07:00 PM, Denys Vlasenko wrote:
> On Fri, Dec 18, 2015 at 2:45 PM, Pascal Bach <pascal.bach at siemens.com> wrote:
>>   int chpasswd_main(int argc UNUSED_PARAM, char **argv)
>>   {
>>          char *name;
>> +       char *algo = CONFIG_FEATURE_DEFAULT_PASSWD_ALGO;
>
> It warns here.
>
>>          int opt;
>>
>>          if (getuid() != 0)
>>                  bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
>>
>> -       opt_complementary = "m--e:e--m";
>> +       opt_complementary = "m--ec:e--mc:c--em";
>>          IF_LONG_OPTS(applet_long_options = chpasswd_longopts;)
>> -       opt = getopt32(argv, "em");
>> +       opt = getopt32(argv, "emc:", &algo);
>>
>>          while ((name = xmalloc_fgetline(stdin)) != NULL) {
>>                  char *free_me;
>> @@ -77,15 +79,14 @@ int chpasswd_main(int argc UNUSED_PARAM, char **argv)
>>
>>                  free_me = NULL;
>>                  if (!(opt & OPT_ENC)) {
>> -                       char salt[sizeof("$N$XXXXXXXX")];
>> +                       char salt[MAX_PW_SALT_LEN];
>>
>> -                       crypt_make_salt(salt, 1);
>>                          if (opt & OPT_MD5) {
>> -                               salt[0] = '$';
>> -                               salt[1] = '1';
>> -                               salt[2] = '$';
>> -                               crypt_make_salt(salt + 3, 4);
>> +                               /* Force MD5 if the -m flag is set */
>> +                               algo = "md5";
>>                          }
>> +
>> +                       crypt_make_pw_salt(salt, algo);
>
> crypt_make_pw_salt() accepts lowercase algos, such as "md5".
> chpasswd examples I googled use uppercase: "MD5".
> So, this won't be compatible.
>
>>                          free_me = pass = pw_encrypt(pass, salt, 0);
>>                  }
Hi,
maybe we could change crypt_make_salt to accept lowercase and uppercase 
algo arguments to keep compatibility with both ways, e.g:

  diff -uNp libbb/pw_encrypt.c.orig libbb/pw_encrypt.c
--- libbb/pw_encrypt.c.orig     2015-03-14 14:39:57.000000000 +0100
+++ libbb/pw_encrypt.c  2015-12-22 14:03:11.645788040 +0100
@@ -52,14 +52,14 @@ char* FAST_FUNC crypt_make_pw_salt(char
  {
         int len = 2/2;
         char *salt_ptr = salt;
-       if (algo[0] != 'd') { /* not des */
+       if (algo[0] != 'd' && algo[0] != 'D') { /* not des */
                 len = 8/2; /* so far assuming md5 */
                 *salt_ptr++ = '$';
                 *salt_ptr++ = '1';
                 *salt_ptr++ = '$';
  #if !ENABLE_USE_BB_CRYPT || ENABLE_USE_BB_CRYPT_SHA
-               if (algo[0] == 's') { /* sha */
-                       salt[1] = '5' + (strcmp(algo, "sha512") == 0);
+               if (algo[0] == 's' && algo[0] == 'S') { /* sha */
+                       salt[1] = '5' + (strcasecmp(algo, "sha512") == 0);
                         len = 16/2;
                 }
  #endif


Only compile tested. Just my 2 cents.

Ciao,
Tito