* libmisc/obscure.c, libmisc/salt.c, src/passwd.c: Match DES, MD5,

SHA256, and SHA512 exactly (not only the first 3/6 chars).
* libmisc/salt.c (SHA_salt_rounds): Set rounds to the specified
  prefered_rounds value, if specified.
* src/gpasswd.c, libmisc/salt.c: Fix compilation warnings (use
  size_t for lengths).
* src/chpasswd.c, src/chgpasswd.c: Add missing parenthesis.

lib/encrypt.c

@@ -49,6 +49,29 @@ char *pw_encrypt (const char *clear, const char *salt)
 		perror ("crypt");
 		exit (1);
 	}
+	if (salt && salt[0] == '$' && strlen (cp) <= 13)
+	{
+		/* The crypt algorithm was not recognized by libcrypt */
+		char *method = "$1$";
+		switch (salt[1])
+		{
+			case '1':
+				method = "MD5";
+				break;
+			case '5':
+				method = "SHA256";
+				break;
+			case '6':
+				method = "SHA512";
+				break;
+			default:
+				method[1] = salt[1];
+		}
+		fprintf (stderr,
+			 _("Unknown crypt method (%s)\n"),
+			  method);
+		exit (1);
+	}
 	if (strlen (cp) != 13)
 		return cp;	/* nonstandard crypt() in libc, better bail out */
 	strcpy (cipher, cp);