libcrypt: add support for SHA256-CRYPT password hashing

This is based on Ulrich Drepper's implementation in GLIBC, but hacked up to work
in uClibc.  The differences from the GLIBC version are as follows:

- b64_from_24bit() has been converted into a macro
- Usage of GLIBC-isms (such as libc_freeres_ptr) have been removed

It is enabled by the UCLIBC_HAS_SHA256_CRYPT_IMPL configuration symbol.  You must
have UCLIBC_HAS_CRYPT_IMPL enabled as well.

Signed-off-by: William Pitcock <nenolod@dereferenced.org>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/libcrypt/sha256.h b/libcrypt/sha256.h
new file mode 100644
index 000000000..291674f35
--- /dev/null
+++ b/libcrypt/sha256.h
@@ -0,0 +1,58 @@
+/* Declaration of functions and data types used for SHA256 sum computing
+   library functions.
+   Copyright (C) 2007 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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.
+
+   The GNU C Library 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 the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _SHA256_H
+#define _SHA256_H 1
+
+#include <limits.h>
+#include <stdint.h>
+#include <stdio.h>
+
+
+/* Structure to save state of computation between the single steps.  */
+struct sha256_ctx
+{
+  uint32_t H[8];
+
+  uint32_t total[2];
+  uint32_t buflen;
+  char buffer[128] __attribute__ ((__aligned__ (__alignof__ (uint32_t))));
+};
+
+/* Initialize structure containing state of computation.
+   (FIPS 180-2: 5.3.2)  */
+extern void __sha256_init_ctx (struct sha256_ctx *ctx) attribute_hidden;
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is NOT required that LEN is a multiple of 64.  */
+extern void __sha256_process_bytes (const void *buffer, size_t len,
+				    struct sha256_ctx *ctx) attribute_hidden;
+
+/* Process the remaining bytes in the buffer and put result from CTX
+   in first 32 bytes following RESBUF.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+extern void *__sha256_finish_ctx (struct sha256_ctx *ctx, void *resbuf)
+  attribute_hidden;
+
+#endif /* sha256.h */