Added Lorenz Quack's native C implementation of all SHA-2 algorithm

(as submitted here https://bugs.launchpad.net/pycrypto/+bug/544792)
so that they are available also in Python 2.1, 2.2, 2.3 and 2.4.

Regardless where the implementation comes from (Python standard
library or our native modules, depending on the Python version),
all Crypto.Hash objects are always used as front-ends.

1 files changed, 104 insertions, 0 deletions

diff --git a/src/hash_SHA2.h b/src/hash_SHA2.h
new file mode 100644
index 0000000..5867191
--- /dev/null
+++ b/src/hash_SHA2.h
@@ -0,0 +1,104 @@
+/*
+ * An generic header for the SHA-2 hash family.
+ *
+ * Written in 2010 by Lorenz Quack <don@amberfisharts.com>
+ * 
+ * ===================================================================
+ * The contents of this file are dedicated to the public domain.  To
+ * the extent that dedication to the public domain is not available,
+ * everyone is granted a worldwide, perpetual, royalty-free,
+ * non-exclusive license to exercise all rights associated with the
+ * contents of this file for any purpose whatsoever.
+ * No rights are reserved.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * ===================================================================
+ *
+ */
+
+#ifndef __HASH_SHA2_H
+#define __HASH_SHA2_H
+
+/* check if implementation set the correct macros */
+#ifndef MODULE_NAME
+#error SHA2 Implementation must define MODULE_NAME before including this header
+#endif
+
+#ifndef DIGEST_SIZE
+#error SHA2 Implementation must define DIGEST_SIZE before including this header
+#else
+#define DIGEST_SIZE_BITS (DIGEST_SIZE*8)
+#endif
+
+#ifndef BLOCK_SIZE
+#error SHA2 Implementation must define BLOCK_SIZE before including this header
+#else
+#define BLOCK_SIZE_BITS (BLOCK_SIZE*8)
+#endif
+
+#ifndef WORD_SIZE
+#error SHA2 Implementation must define WORD_SIZE before including this header
+#else
+#if ((WORD_SIZE != 4) && (WORD_SIZE != 8))
+#error WORD_SIZE must be either 4 or 8
+#else
+#define WORD_SIZE_BITS (WORD_SIZE*8)
+#endif
+#endif
+
+#ifndef SCHEDULE_SIZE
+#error SHA2 Implementation must define SCHEDULE_SIZE before including this header
+#endif
+
+/* define some helper macros */
+#define PADDING_SIZE (2 * WORD_SIZE)
+#define LAST_BLOCK_SIZE (BLOCK_SIZE - PADDING_SIZE)
+
+/* define generic SHA-2 family functions */
+#define Ch(x,y,z)   ((x & y) ^ (~x & z))
+#define Maj(x,y,z)  ((x & y) ^ (x & z) ^ (y & z))
+#define ROTR(x, n)  (((x)>>((n)&(WORD_SIZE_BITS-1)))|((x)<<(WORD_SIZE_BITS-((n)&(WORD_SIZE_BITS-1)))))
+#define SHR(x, n)   ((x)>>(n))
+
+/* determine fixed size types */
+#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)
+#include <stdint.h>
+typedef uint8_t				U8;
+typedef uint32_t			U32;
+typedef uint64_t			U64;
+#elif defined(_MSC_VER)
+typedef unsigned char		U8;
+typedef unsigned __int64	U64;
+typedef unsigned int		U32;
+#elif defined(__sun) || defined(__sun__)
+#include <sys/inttypes.h>
+typedef uint8_t				U8;
+typedef uint32_t			U32;
+typedef uint64_t			U64;
+#endif
+
+/* typedef a sha2_word_t type of appropriate size */
+#if (WORD_SIZE_BITS == 64)
+typedef U64 sha2_word_t;
+#elif (WORD_SIZE_BITS == 32)
+typedef U32 sha2_word_t;
+#else
+#error According to the FIPS Standard WORD_SIZE_BITS must be either 32 or 64
+#endif
+
+/* define the hash_state structure */
+typedef struct{
+    sha2_word_t state[8];
+    int curlen;
+    sha2_word_t length_upper, length_lower;
+    unsigned char buf[BLOCK_SIZE];
+} hash_state;
+
+#endif /* __HASH_SHA2_H */