Add some _XOPEN_CRYPT stuff.

1 files changed, 66 insertions, 0 deletions

diff --git a/crypt/crypt.go b/crypt/crypt.go
new file mode 100644
index 0000000..40b5149
--- /dev/null
+++ b/crypt/crypt.go
@@ -0,0 +1,66 @@
+// Copyright 2015-2016 Luke Shumaker <lukeshu@sbcglobal.net>.
+//
+// This is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation; either version 2.1 of the
+// License, or (at your option) any later version.
+//
+// This software is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this manual; if not, see
+// <http://www.gnu.org/licenses/>.
+
+// Package crypt provides an interface to the POSIX CRYPT option
+// group.
+//
+// Actually, it doesn't yet support encrypt() or setkey()
+package crypt
+
+import "unsafe"
+
+/*
+#cgo LDFLAGS: -lcrypt
+#define _GNU_SOURCE // for crypt_r(3) in crypt.h
+#include <stdlib.h> // for free(3)
+#include <crypt.h>  // for crypt_r(3)
+#include <string.h> // for strdup(3) and memset(3)
+char *c_crypt(const char *key, const char *salt)
+{
+  struct crypt_data data;
+  data.initialized = 0;
+  char *hash = crypt_r(key, salt, &data);
+  if (hash)
+    hash = strdup(hash);
+  memset(&data, 0, sizeof(data));
+  return hash;
+}
+*/
+import "C"
+
+func Crypt(key string, salt string) string {
+	ckey := C.CString(key)
+	defer C.free(unsafe.Pointer(ckey))
+	csalt := C.CString(salt)
+	defer C.free(unsafe.Pointer(csalt))
+	chash := C.c_crypt(ckey, csalt)
+	defer C.free(unsafe.Pointer(chash))
+	hash := C.GoString(chash)
+	return hash
+}
+
+func SaltOk(salt string) bool {
+	if len(salt) < 2 {
+		return false
+	}
+	hash := Crypt("", salt)
+	if len(hash) < 2 {
+		return false
+	}
+	return salt[0] == hash[0] && salt[1] == hash[1]
+}
+
+const SaltAlphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789./"