[ sf.net patch # 1121611 ]

A new hashlib module to replace the md5 and sha modules.  It adds
support for additional secure hashes such as SHA-256 and SHA-512.  The
hashlib module uses OpenSSL for fast platform optimized
implementations of algorithms when available.  The old md5 and sha
modules still exist as wrappers around hashlib to preserve backwards
compatibility.

1 files changed, 709 insertions, 0 deletions

diff --git a/Modules/sha256module.c b/Modules/sha256module.c
new file mode 100644
index 0000000..8da36b7
--- /dev/null
+++ b/Modules/sha256module.c
@@ -0,0 +1,709 @@
+/* SHA256 module */
+
+/* This module provides an interface to NIST's SHA-256 and SHA-224 Algorithms */
+
+/* See below for information about the original code this module was
+   based upon. Additional work performed by:
+
+   Andrew Kuchling (amk@amk.ca)
+   Greg Stein (gstein@lyra.org)
+   Trevor Perrin (trevp@trevp.net)
+
+   Copyright (C) 2005   Gregory P. Smith (greg@electricrain.com)
+   Licensed to PSF under a Contributor Agreement.
+
+*/
+
+/* SHA objects */
+
+#include "Python.h"
+#include "structmember.h"
+
+
+/* Endianness testing and definitions */
+#define TestEndianness(variable) {int i=1; variable=PCT_BIG_ENDIAN;\
+	if (*((char*)&i)==1) variable=PCT_LITTLE_ENDIAN;}
+
+#define PCT_LITTLE_ENDIAN 1
+#define PCT_BIG_ENDIAN 0
+
+/* Some useful types */
+
+typedef unsigned char SHA_BYTE;
+
+#if SIZEOF_INT == 4
+typedef unsigned int SHA_INT32;	/* 32-bit integer */
+#else
+/* not defined. compilation will die. */
+#endif
+
+/* The SHA block size and message digest sizes, in bytes */
+
+#define SHA_BLOCKSIZE    64
+#define SHA_DIGESTSIZE  32
+
+/* The structure for storing SHA info */
+
+typedef struct {
+    PyObject_HEAD
+    SHA_INT32 digest[8];		/* Message digest */
+    SHA_INT32 count_lo, count_hi;	/* 64-bit bit count */
+    SHA_BYTE data[SHA_BLOCKSIZE];	/* SHA data buffer */
+    int Endianness;
+    int local;				/* unprocessed amount in data */
+    int digestsize;
+} SHAobject;
+
+/* When run on a little-endian CPU we need to perform byte reversal on an
+   array of longwords. */
+
+static void longReverse(SHA_INT32 *buffer, int byteCount, int Endianness)
+{
+    SHA_INT32 value;
+
+    if ( Endianness == PCT_BIG_ENDIAN )
+	return;
+
+    byteCount /= sizeof(*buffer);
+    while (byteCount--) {
+        value = *buffer;
+        value = ( ( value & 0xFF00FF00L ) >> 8  ) | \
+                ( ( value & 0x00FF00FFL ) << 8 );
+        *buffer++ = ( value << 16 ) | ( value >> 16 );
+    }
+}
+
+static void SHAcopy(SHAobject *src, SHAobject *dest)
+{
+    dest->Endianness = src->Endianness;
+    dest->local = src->local;
+    dest->digestsize = src->digestsize;
+    dest->count_lo = src->count_lo;
+    dest->count_hi = src->count_hi;
+    memcpy(dest->digest, src->digest, sizeof(src->digest));
+    memcpy(dest->data, src->data, sizeof(src->data));
+}
+
+
+/* ------------------------------------------------------------------------
+ *
+ * This code for the SHA-256 algorithm was noted as public domain. The
+ * original headers are pasted below.
+ *
+ * Several changes have been made to make it more compatible with the
+ * Python environment and desired interface.
+ *
+ */
+
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * gurantee it works.
+ *
+ * Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org
+ */
+
+
+/* SHA256 by Tom St Denis */
+
+/* Various logical functions */
+#define ROR(x, y)\
+( ((((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)((y)&31)) | \
+((unsigned long)(x)<<(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)
+#define Ch(x,y,z)       (z ^ (x & (y ^ z)))
+#define Maj(x,y,z)      (((x | y) & z) | (x & y)) 
+#define S(x, n)         ROR((x),(n))
+#define R(x, n)         (((x)&0xFFFFFFFFUL)>>(n))
+#define Sigma0(x)       (S(x, 2) ^ S(x, 13) ^ S(x, 22))
+#define Sigma1(x)       (S(x, 6) ^ S(x, 11) ^ S(x, 25))
+#define Gamma0(x)       (S(x, 7) ^ S(x, 18) ^ R(x, 3))
+#define Gamma1(x)       (S(x, 17) ^ S(x, 19) ^ R(x, 10))
+
+
+static void
+sha_transform(SHAobject *sha_info)
+{
+    int i;
+	SHA_INT32 S[8], W[64], t0, t1;
+
+    memcpy(W, sha_info->data, sizeof(sha_info->data));
+    longReverse(W, (int)sizeof(sha_info->data), sha_info->Endianness);
+
+    for (i = 16; i < 64; ++i) {
+		W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16];
+    }
+    for (i = 0; i < 8; ++i) {
+        S[i] = sha_info->digest[i];
+    }
+
+    /* Compress */
+#define RND(a,b,c,d,e,f,g,h,i,ki)                    \
+     t0 = h + Sigma1(e) + Ch(e, f, g) + ki + W[i];   \
+     t1 = Sigma0(a) + Maj(a, b, c);                  \
+     d += t0;                                        \
+     h  = t0 + t1;
+
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],0,0x428a2f98);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],1,0x71374491);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],2,0xb5c0fbcf);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],3,0xe9b5dba5);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],4,0x3956c25b);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],5,0x59f111f1);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],6,0x923f82a4);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],7,0xab1c5ed5);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],8,0xd807aa98);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],9,0x12835b01);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],10,0x243185be);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],11,0x550c7dc3);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],12,0x72be5d74);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],13,0x80deb1fe);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],14,0x9bdc06a7);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],15,0xc19bf174);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],16,0xe49b69c1);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],17,0xefbe4786);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],18,0x0fc19dc6);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],19,0x240ca1cc);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],20,0x2de92c6f);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],21,0x4a7484aa);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],22,0x5cb0a9dc);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],23,0x76f988da);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],24,0x983e5152);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],25,0xa831c66d);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],26,0xb00327c8);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],27,0xbf597fc7);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],28,0xc6e00bf3);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],29,0xd5a79147);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],30,0x06ca6351);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],31,0x14292967);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],32,0x27b70a85);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],33,0x2e1b2138);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],34,0x4d2c6dfc);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],35,0x53380d13);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],36,0x650a7354);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],37,0x766a0abb);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],38,0x81c2c92e);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],39,0x92722c85);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],40,0xa2bfe8a1);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],41,0xa81a664b);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],42,0xc24b8b70);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],43,0xc76c51a3);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],44,0xd192e819);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],45,0xd6990624);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],46,0xf40e3585);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],47,0x106aa070);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],48,0x19a4c116);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],49,0x1e376c08);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],50,0x2748774c);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],51,0x34b0bcb5);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],52,0x391c0cb3);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],53,0x4ed8aa4a);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],54,0x5b9cca4f);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],55,0x682e6ff3);
+    RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],56,0x748f82ee);
+    RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],57,0x78a5636f);
+    RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],58,0x84c87814);
+    RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],59,0x8cc70208);
+    RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],60,0x90befffa);
+    RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],61,0xa4506ceb);
+    RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],62,0xbef9a3f7);
+    RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],63,0xc67178f2);
+
+#undef RND     
+    
+    /* feedback */
+    for (i = 0; i < 8; i++) {
+        sha_info->digest[i] = sha_info->digest[i] + S[i];
+    }
+
+}
+
+
+
+/* initialize the SHA digest */
+
+static void
+sha_init(SHAobject *sha_info)
+{
+    TestEndianness(sha_info->Endianness)
+    sha_info->digest[0] = 0x6A09E667L;
+    sha_info->digest[1] = 0xBB67AE85L;
+    sha_info->digest[2] = 0x3C6EF372L;
+    sha_info->digest[3] = 0xA54FF53AL;
+    sha_info->digest[4] = 0x510E527FL;
+    sha_info->digest[5] = 0x9B05688CL;
+    sha_info->digest[6] = 0x1F83D9ABL;
+    sha_info->digest[7] = 0x5BE0CD19L;
+    sha_info->count_lo = 0L;
+    sha_info->count_hi = 0L;
+    sha_info->local = 0;
+    sha_info->digestsize = 32;
+}
+
+static void
+sha224_init(SHAobject *sha_info)
+{
+    TestEndianness(sha_info->Endianness)
+    sha_info->digest[0] = 0xc1059ed8L;
+    sha_info->digest[1] = 0x367cd507L;
+    sha_info->digest[2] = 0x3070dd17L;
+    sha_info->digest[3] = 0xf70e5939L;
+    sha_info->digest[4] = 0xffc00b31L;
+    sha_info->digest[5] = 0x68581511L;
+    sha_info->digest[6] = 0x64f98fa7L;
+    sha_info->digest[7] = 0xbefa4fa4L;
+    sha_info->count_lo = 0L;
+    sha_info->count_hi = 0L;
+    sha_info->local = 0;
+    sha_info->digestsize = 28;
+}
+
+
+/* update the SHA digest */
+
+static void
+sha_update(SHAobject *sha_info, SHA_BYTE *buffer, int count)
+{
+    int i;
+    SHA_INT32 clo;
+
+    clo = sha_info->count_lo + ((SHA_INT32) count << 3);
+    if (clo < sha_info->count_lo) {
+        ++sha_info->count_hi;
+    }
+    sha_info->count_lo = clo;
+    sha_info->count_hi += (SHA_INT32) count >> 29;
+    if (sha_info->local) {
+        i = SHA_BLOCKSIZE - sha_info->local;
+        if (i > count) {
+            i = count;
+        }
+        memcpy(((SHA_BYTE *) sha_info->data) + sha_info->local, buffer, i);
+        count -= i;
+        buffer += i;
+        sha_info->local += i;
+        if (sha_info->local == SHA_BLOCKSIZE) {
+            sha_transform(sha_info);
+        }
+        else {
+            return;
+        }
+    }
+    while (count >= SHA_BLOCKSIZE) {
+        memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
+        buffer += SHA_BLOCKSIZE;
+        count -= SHA_BLOCKSIZE;
+        sha_transform(sha_info);
+    }
+    memcpy(sha_info->data, buffer, count);
+    sha_info->local = count;
+}
+
+/* finish computing the SHA digest */
+
+static void
+sha_final(unsigned char digest[SHA_DIGESTSIZE], SHAobject *sha_info)
+{
+    int count;
+    SHA_INT32 lo_bit_count, hi_bit_count;
+
+    lo_bit_count = sha_info->count_lo;
+    hi_bit_count = sha_info->count_hi;
+    count = (int) ((lo_bit_count >> 3) & 0x3f);
+    ((SHA_BYTE *) sha_info->data)[count++] = 0x80;
+    if (count > SHA_BLOCKSIZE - 8) {
+	memset(((SHA_BYTE *) sha_info->data) + count, 0,
+	       SHA_BLOCKSIZE - count);
+	sha_transform(sha_info);
+	memset((SHA_BYTE *) sha_info->data, 0, SHA_BLOCKSIZE - 8);
+    }
+    else {
+	memset(((SHA_BYTE *) sha_info->data) + count, 0,
+	       SHA_BLOCKSIZE - 8 - count);
+    }
+
+    /* GJS: note that we add the hi/lo in big-endian. sha_transform will
+       swap these values into host-order. */
+    sha_info->data[56] = (hi_bit_count >> 24) & 0xff;
+    sha_info->data[57] = (hi_bit_count >> 16) & 0xff;
+    sha_info->data[58] = (hi_bit_count >>  8) & 0xff;
+    sha_info->data[59] = (hi_bit_count >>  0) & 0xff;
+    sha_info->data[60] = (lo_bit_count >> 24) & 0xff;
+    sha_info->data[61] = (lo_bit_count >> 16) & 0xff;
+    sha_info->data[62] = (lo_bit_count >>  8) & 0xff;
+    sha_info->data[63] = (lo_bit_count >>  0) & 0xff;
+    sha_transform(sha_info);
+    digest[ 0] = (unsigned char) ((sha_info->digest[0] >> 24) & 0xff);
+    digest[ 1] = (unsigned char) ((sha_info->digest[0] >> 16) & 0xff);
+    digest[ 2] = (unsigned char) ((sha_info->digest[0] >>  8) & 0xff);
+    digest[ 3] = (unsigned char) ((sha_info->digest[0]      ) & 0xff);
+    digest[ 4] = (unsigned char) ((sha_info->digest[1] >> 24) & 0xff);
+    digest[ 5] = (unsigned char) ((sha_info->digest[1] >> 16) & 0xff);
+    digest[ 6] = (unsigned char) ((sha_info->digest[1] >>  8) & 0xff);
+    digest[ 7] = (unsigned char) ((sha_info->digest[1]      ) & 0xff);
+    digest[ 8] = (unsigned char) ((sha_info->digest[2] >> 24) & 0xff);
+    digest[ 9] = (unsigned char) ((sha_info->digest[2] >> 16) & 0xff);
+    digest[10] = (unsigned char) ((sha_info->digest[2] >>  8) & 0xff);
+    digest[11] = (unsigned char) ((sha_info->digest[2]      ) & 0xff);
+    digest[12] = (unsigned char) ((sha_info->digest[3] >> 24) & 0xff);
+    digest[13] = (unsigned char) ((sha_info->digest[3] >> 16) & 0xff);
+    digest[14] = (unsigned char) ((sha_info->digest[3] >>  8) & 0xff);
+    digest[15] = (unsigned char) ((sha_info->digest[3]      ) & 0xff);
+    digest[16] = (unsigned char) ((sha_info->digest[4] >> 24) & 0xff);
+    digest[17] = (unsigned char) ((sha_info->digest[4] >> 16) & 0xff);
+    digest[18] = (unsigned char) ((sha_info->digest[4] >>  8) & 0xff);
+    digest[19] = (unsigned char) ((sha_info->digest[4]      ) & 0xff);
+    digest[20] = (unsigned char) ((sha_info->digest[5] >> 24) & 0xff);
+    digest[21] = (unsigned char) ((sha_info->digest[5] >> 16) & 0xff);
+    digest[22] = (unsigned char) ((sha_info->digest[5] >>  8) & 0xff);
+    digest[23] = (unsigned char) ((sha_info->digest[5]      ) & 0xff);
+    digest[24] = (unsigned char) ((sha_info->digest[6] >> 24) & 0xff);
+    digest[25] = (unsigned char) ((sha_info->digest[6] >> 16) & 0xff);
+    digest[26] = (unsigned char) ((sha_info->digest[6] >>  8) & 0xff);
+    digest[27] = (unsigned char) ((sha_info->digest[6]      ) & 0xff);
+    digest[28] = (unsigned char) ((sha_info->digest[7] >> 24) & 0xff);
+    digest[29] = (unsigned char) ((sha_info->digest[7] >> 16) & 0xff);
+    digest[30] = (unsigned char) ((sha_info->digest[7] >>  8) & 0xff);
+    digest[31] = (unsigned char) ((sha_info->digest[7]      ) & 0xff);
+}
+
+/*
+ * End of copied SHA code.
+ *
+ * ------------------------------------------------------------------------
+ */
+
+static PyTypeObject SHA224type;
+static PyTypeObject SHA256type;
+
+
+static SHAobject *
+newSHA224object(void)
+{
+    return (SHAobject *)PyObject_New(SHAobject, &SHA224type);
+}
+
+static SHAobject *
+newSHA256object(void)
+{
+    return (SHAobject *)PyObject_New(SHAobject, &SHA256type);
+}
+
+/* Internal methods for a hash object */
+
+static void
+SHA_dealloc(PyObject *ptr)
+{
+    PyObject_Del(ptr);
+}
+
+
+/* External methods for a hash object */
+
+PyDoc_STRVAR(SHA256_copy__doc__, "Return a copy of the hash object.");
+
+static PyObject *
+SHA256_copy(SHAobject *self, PyObject *args)
+{
+    SHAobject *newobj;
+
+    if (!PyArg_ParseTuple(args, ":copy")) {
+        return NULL;
+    }
+
+    if (((PyObject*)self)->ob_type == &SHA256type) {
+        if ( (newobj = newSHA256object())==NULL)
+            return NULL;
+    } else {
+        if ( (newobj = newSHA224object())==NULL)
+            return NULL;
+    }
+
+    SHAcopy(self, newobj);
+    return (PyObject *)newobj;
+}
+
+PyDoc_STRVAR(SHA256_digest__doc__,
+"Return the digest value as a string of binary data.");
+
+static PyObject *
+SHA256_digest(SHAobject *self, PyObject *args)
+{
+    unsigned char digest[SHA_DIGESTSIZE];
+    SHAobject temp;
+
+    if (!PyArg_ParseTuple(args, ":digest"))
+        return NULL;
+
+    SHAcopy(self, &temp);
+    sha_final(digest, &temp);
+    return PyString_FromStringAndSize((const char *)digest, self->digestsize);
+}
+
+PyDoc_STRVAR(SHA256_hexdigest__doc__,
+"Return the digest value as a string of hexadecimal digits.");
+
+static PyObject *
+SHA256_hexdigest(SHAobject *self, PyObject *args)
+{
+    unsigned char digest[SHA_DIGESTSIZE];
+    SHAobject temp;
+    PyObject *retval;
+    char *hex_digest;
+    int i, j;
+
+    if (!PyArg_ParseTuple(args, ":hexdigest"))
+        return NULL;
+
+    /* Get the raw (binary) digest value */
+    SHAcopy(self, &temp);
+    sha_final(digest, &temp);
+
+    /* Create a new string */
+    retval = PyString_FromStringAndSize(NULL, self->digestsize * 2);
+    if (!retval)
+	    return NULL;
+    hex_digest = PyString_AsString(retval);
+    if (!hex_digest) {
+	    Py_DECREF(retval);
+	    return NULL;
+    }
+
+    /* Make hex version of the digest */
+    for(i=j=0; i<self->digestsize; i++) {
+        char c;
+        c = (digest[i] >> 4) & 0xf;
+	c = (c>9) ? c+'a'-10 : c + '0';
+        hex_digest[j++] = c;
+        c = (digest[i] & 0xf);
+	c = (c>9) ? c+'a'-10 : c + '0';
+        hex_digest[j++] = c;
+    }
+    return retval;
+}
+
+PyDoc_STRVAR(SHA256_update__doc__,
+"Update this hash object's state with the provided string.");
+
+static PyObject *
+SHA256_update(SHAobject *self, PyObject *args)
+{
+    unsigned char *cp;
+    int len;
+
+    if (!PyArg_ParseTuple(args, "s#:update", &cp, &len))
+        return NULL;
+
+    sha_update(self, cp, len);
+
+    Py_INCREF(Py_None);
+    return Py_None;
+}
+
+static PyMethodDef SHA_methods[] = {
+    {"copy",	  (PyCFunction)SHA256_copy,      METH_VARARGS, SHA256_copy__doc__},
+    {"digest",	  (PyCFunction)SHA256_digest,    METH_VARARGS, SHA256_digest__doc__},
+    {"hexdigest", (PyCFunction)SHA256_hexdigest, METH_VARARGS, SHA256_hexdigest__doc__},
+    {"update",	  (PyCFunction)SHA256_update,    METH_VARARGS, SHA256_update__doc__},
+    {NULL,	  NULL}		/* sentinel */
+};
+
+static PyObject *
+SHA256_get_block_size(PyObject *self, void *closure)
+{
+    return PyInt_FromLong(SHA_BLOCKSIZE);
+}
+
+static PyObject *
+SHA256_get_name(PyObject *self, void *closure)
+{
+    if (((SHAobject *)self)->digestsize == 32)
+        return PyString_FromStringAndSize("SHA256", 6);
+    else
+        return PyString_FromStringAndSize("SHA224", 6);
+}
+
+static PyGetSetDef SHA_getseters[] = {
+    {"block_size",
+     (getter)SHA256_get_block_size, NULL,
+     NULL,
+     NULL},
+    {"name",
+     (getter)SHA256_get_name, NULL,
+     NULL,
+     NULL},
+    {NULL}  /* Sentinel */
+};
+
+static PyMemberDef SHA_members[] = {
+    {"digest_size", T_INT, offsetof(SHAobject, digestsize), READONLY, NULL},
+    /* the old md5 and sha modules support 'digest_size' as in PEP 247.
+     * the old sha module also supported 'digestsize'.  ugh. */
+    {"digestsize", T_INT, offsetof(SHAobject, digestsize), READONLY, NULL},
+    {NULL}  /* Sentinel */
+};
+
+static PyTypeObject SHA224type = {
+    PyObject_HEAD_INIT(NULL)
+    0,			/*ob_size*/
+    "_sha256.sha224",	/*tp_name*/
+    sizeof(SHAobject),	/*tp_size*/
+    0,			/*tp_itemsize*/
+    /* methods */
+    SHA_dealloc,	/*tp_dealloc*/
+    0,			/*tp_print*/
+    0,          	/*tp_getattr*/
+    0,                  /*tp_setattr*/
+    0,                  /*tp_compare*/
+    0,                  /*tp_repr*/
+    0,                  /*tp_as_number*/
+    0,                  /*tp_as_sequence*/
+    0,                  /*tp_as_mapping*/
+    0,                  /*tp_hash*/
+    0,                  /*tp_call*/
+    0,                  /*tp_str*/
+    0,                  /*tp_getattro*/
+    0,                  /*tp_setattro*/
+    0,                  /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT, /*tp_flags*/
+    0,                  /*tp_doc*/
+    0,                  /*tp_traverse*/
+    0,			/*tp_clear*/
+    0,			/*tp_richcompare*/
+    0,			/*tp_weaklistoffset*/
+    0,			/*tp_iter*/
+    0,			/*tp_iternext*/
+    SHA_methods,	/* tp_methods */
+    SHA_members,	/* tp_members */
+    SHA_getseters,      /* tp_getset */
+};
+
+static PyTypeObject SHA256type = {
+    PyObject_HEAD_INIT(NULL)
+    0,			/*ob_size*/
+    "_sha256.sha256",	/*tp_name*/
+    sizeof(SHAobject),	/*tp_size*/
+    0,			/*tp_itemsize*/
+    /* methods */
+    SHA_dealloc,	/*tp_dealloc*/
+    0,			/*tp_print*/
+    0,          	/*tp_getattr*/
+    0,                  /*tp_setattr*/
+    0,                  /*tp_compare*/
+    0,                  /*tp_repr*/
+    0,                  /*tp_as_number*/
+    0,                  /*tp_as_sequence*/
+    0,                  /*tp_as_mapping*/
+    0,                  /*tp_hash*/
+    0,                  /*tp_call*/
+    0,                  /*tp_str*/
+    0,                  /*tp_getattro*/
+    0,                  /*tp_setattro*/
+    0,                  /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT, /*tp_flags*/
+    0,                  /*tp_doc*/
+    0,                  /*tp_traverse*/
+    0,			/*tp_clear*/
+    0,			/*tp_richcompare*/
+    0,			/*tp_weaklistoffset*/
+    0,			/*tp_iter*/
+    0,			/*tp_iternext*/
+    SHA_methods,	/* tp_methods */
+    SHA_members,	/* tp_members */
+    SHA_getseters,      /* tp_getset */
+};
+
+
+/* The single module-level function: new() */
+
+PyDoc_STRVAR(SHA256_new__doc__,
+"Return a new SHA-256 hash object; optionally initialized with a string.");
+
+static PyObject *
+SHA256_new(PyObject *self, PyObject *args, PyObject *kwdict)
+{
+    static char *kwlist[] = {"string", NULL};
+    SHAobject *new;
+    unsigned char *cp = NULL;
+    int len;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s#:new", kwlist,
+                                     &cp, &len)) {
+        return NULL;
+    }
+
+    if ((new = newSHA256object()) == NULL)
+        return NULL;
+
+    sha_init(new);
+
+    if (PyErr_Occurred()) {
+        Py_DECREF(new);
+        return NULL;
+    }
+    if (cp)
+        sha_update(new, cp, len);
+
+    return (PyObject *)new;
+}
+
+PyDoc_STRVAR(SHA224_new__doc__,
+"Return a new SHA-224 hash object; optionally initialized with a string.");
+
+static PyObject *
+SHA224_new(PyObject *self, PyObject *args, PyObject *kwdict)
+{
+    static char *kwlist[] = {"string", NULL};
+    SHAobject *new;
+    unsigned char *cp = NULL;
+    int len;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s#:new", kwlist,
+                                     &cp, &len)) {
+        return NULL;
+    }
+
+    if ((new = newSHA224object()) == NULL)
+        return NULL;
+
+    sha224_init(new);
+
+    if (PyErr_Occurred()) {
+        Py_DECREF(new);
+        return NULL;
+    }
+    if (cp)
+        sha_update(new, cp, len);
+
+    return (PyObject *)new;
+}
+
+
+/* List of functions exported by this module */
+
+static struct PyMethodDef SHA_functions[] = {
+    {"sha256", (PyCFunction)SHA256_new, METH_VARARGS|METH_KEYWORDS, SHA256_new__doc__},
+    {"sha224", (PyCFunction)SHA224_new, METH_VARARGS|METH_KEYWORDS, SHA224_new__doc__},
+    {NULL,	NULL}		 /* Sentinel */
+};
+
+
+/* Initialize this module. */
+
+#define insint(n,v) { PyModule_AddIntConstant(m,n,v); }
+
+PyMODINIT_FUNC
+init_sha256(void)
+{
+    PyObject *m;
+
+    SHA224type.ob_type = &PyType_Type;
+    if (PyType_Ready(&SHA224type) < 0)
+        return;
+    SHA256type.ob_type = &PyType_Type;
+    if (PyType_Ready(&SHA256type) < 0)
+        return;
+    m = Py_InitModule("_sha256", SHA_functions);
+}