--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/mkpasswd.c	Wed Oct 16 20:41:56 2013 -0500
@@ -0,0 +1,103 @@
+/* mkpasswd.c - encrypt the given passwd using salt
+ *
+ * Copyright 2013 Ashwini Kumar <ak.ashwini@gmail.com>
+ * Copyright 2013 Kyungwan Han <asura321@gmail.com>
+ *
+ * No Standard
+
+USE_MKPASSWD(NEWTOY(mkpasswd, ">2S:m:P#=0<0", TOYFLAG_USR|TOYFLAG_BIN))
+
+config MKPASSWD
+  bool "mkpasswd"
+  default n
+  help
+    usage: mkpasswd [OPTIONS] [PASSWORD] [SALT]
+
+    Crypt PASSWORD using crypt(3)
+
+    -P N    Read password from fd N
+    -m TYPE Encryption method, when TYPE='help', then show the methods available
+    -S SALT
+*/
+
+#define FOR_mkpasswd
+#include "toys.h"
+#include "lib/xregcomp.h"
+
+GLOBALS(
+  long pfd;
+  char *method;
+  char *salt;
+)
+
+
+/*
+ * validate the salt provided by user.
+ * the allowed character set for salt is [./A-Za-z0-9]
+ */
+static void is_salt_valid(char *salt)
+{
+  regex_t rp;
+  regmatch_t rm[1];
+  char *regex = "[./A-Za-z0-9]*"; //salt REGEX
+
+  xregcomp(&rp, regex, REG_NEWLINE);
+
+  /* compare string against pattern --  remember that patterns 
+     are anchored to the beginning of the line */
+  if (regexec(&rp, salt, 1, rm, 0) == 0 && rm[0].rm_so == 0 
+      && rm[0].rm_eo == strlen(salt))
+      return;
+
+  error_exit("salt should be in character set [./A-Za-z0-9]");
+}
+
+void mkpasswd_main(void)
+{
+  int offset = 0;
+  char salt[MAX_SALT_LEN] = {0,};
+
+  if (!(toys.optflags & FLAG_m)) TT.method = "des";
+  else if (!strcmp(TT.method, "help")) {
+    xprintf("Available encryption methods are:\n"
+        " des\n md5\n sha256\n sha512\n");
+    return;
+  }
+  // If arguments are there, then the second argument is Salt, can be NULL also
+  if ((toys.optc == 2) && !(toys.optflags & FLAG_S)) TT.salt = toys.optargs[1];
+
+  offset= get_salt(salt, TT.method);
+  if (offset == -1) error_exit("unknown encryption method");
+  if (TT.salt) {
+    is_salt_valid(TT.salt);
+    snprintf(salt + offset, MAX_SALT_LEN - offset, "%s", TT.salt);
+  }
+
+  if (toys.optflags & FLAG_P) {
+    if (dup2(TT.pfd, STDIN_FILENO) == -1) perror_exit("fd");
+    close(TT.pfd);
+  }
+
+  if (!toys.optc) {
+    if (isatty(STDIN_FILENO)) {
+      if (read_password(toybuf, sizeof(toybuf), "Password: ")) 
+        perror_exit("password read failed");
+    } else {
+      // read from the given FD
+      int i = 0;
+      while (1) {
+        int ret = read(0, &toybuf[i], 1);
+        if ( ret < 0 ) perror_exit("password read failed");
+        else if (ret == 0 || toybuf[i] == '\n' || toybuf[i] == '\r' ||
+            sizeof(toybuf) == i+1) {
+          toybuf[i] = '\0';
+          break;
+        }
+        i++;
+      }
+    }
+  } else snprintf(toybuf, sizeof(toybuf), "%s", toys.optargs[0]);
+
+  // encrypt & print the password
+  xprintf("%s\n",crypt(toybuf, salt));
+}