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cpython/Modules/shamodule.c
Gregory P. Smith f21a5f7739 [ 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.
2005-08-21 18:45:59 +00:00

601 lines
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/* SHA module */
/* This module provides an interface to NIST's Secure Hash Algorithm */
/* 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)
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 20
/* The structure for storing SHS info */
typedef struct {
PyObject_HEAD
SHA_INT32 digest[5]; /* 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 */
} 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->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 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.
*
*/
/* NIST Secure Hash Algorithm */
/* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
/* from Peter C. Gutmann's implementation as found in */
/* Applied Cryptography by Bruce Schneier */
/* Further modifications to include the "UNRAVEL" stuff, below */
/* This code is in the public domain */
/* UNRAVEL should be fastest & biggest */
/* UNROLL_LOOPS should be just as big, but slightly slower */
/* both undefined should be smallest and slowest */
#define UNRAVEL
/* #define UNROLL_LOOPS */
/* The SHA f()-functions. The f1 and f3 functions can be optimized to
save one boolean operation each - thanks to Rich Schroeppel,
rcs@cs.arizona.edu for discovering this */
/*#define f1(x,y,z) ((x & y) | (~x & z)) // Rounds 0-19 */
#define f1(x,y,z) (z ^ (x & (y ^ z))) /* Rounds 0-19 */
#define f2(x,y,z) (x ^ y ^ z) /* Rounds 20-39 */
/*#define f3(x,y,z) ((x & y) | (x & z) | (y & z)) // Rounds 40-59 */
#define f3(x,y,z) ((x & y) | (z & (x | y))) /* Rounds 40-59 */
#define f4(x,y,z) (x ^ y ^ z) /* Rounds 60-79 */
/* SHA constants */
#define CONST1 0x5a827999L /* Rounds 0-19 */
#define CONST2 0x6ed9eba1L /* Rounds 20-39 */
#define CONST3 0x8f1bbcdcL /* Rounds 40-59 */
#define CONST4 0xca62c1d6L /* Rounds 60-79 */
/* 32-bit rotate */
#define R32(x,n) ((x << n) | (x >> (32 - n)))
/* the generic case, for when the overall rotation is not unraveled */
#define FG(n) \
T = R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n; \
E = D; D = C; C = R32(B,30); B = A; A = T
/* specific cases, for when the overall rotation is unraveled */
#define FA(n) \
T = R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n; B = R32(B,30)
#define FB(n) \
E = R32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n; A = R32(A,30)
#define FC(n) \
D = R32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n; T = R32(T,30)
#define FD(n) \
C = R32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n; E = R32(E,30)
#define FE(n) \
B = R32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n; D = R32(D,30)
#define FT(n) \
A = R32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n; C = R32(C,30)
/* do SHA transformation */
static void
sha_transform(SHAobject *sha_info)
{
int i;
SHA_INT32 T, A, B, C, D, E, W[80], *WP;
memcpy(W, sha_info->data, sizeof(sha_info->data));
longReverse(W, (int)sizeof(sha_info->data), sha_info->Endianness);
for (i = 16; i < 80; ++i) {
W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
/* extra rotation fix */
W[i] = R32(W[i], 1);
}
A = sha_info->digest[0];
B = sha_info->digest[1];
C = sha_info->digest[2];
D = sha_info->digest[3];
E = sha_info->digest[4];
WP = W;
#ifdef UNRAVEL
FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);
sha_info->digest[0] += E;
sha_info->digest[1] += T;
sha_info->digest[2] += A;
sha_info->digest[3] += B;
sha_info->digest[4] += C;
#else /* !UNRAVEL */
#ifdef UNROLL_LOOPS
FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
#else /* !UNROLL_LOOPS */
for (i = 0; i < 20; ++i) { FG(1); }
for (i = 20; i < 40; ++i) { FG(2); }
for (i = 40; i < 60; ++i) { FG(3); }
for (i = 60; i < 80; ++i) { FG(4); }
#endif /* !UNROLL_LOOPS */
sha_info->digest[0] += A;
sha_info->digest[1] += B;
sha_info->digest[2] += C;
sha_info->digest[3] += D;
sha_info->digest[4] += E;
#endif /* !UNRAVEL */
}
/* initialize the SHA digest */
static void
sha_init(SHAobject *sha_info)
{
TestEndianness(sha_info->Endianness)
sha_info->digest[0] = 0x67452301L;
sha_info->digest[1] = 0xefcdab89L;
sha_info->digest[2] = 0x98badcfeL;
sha_info->digest[3] = 0x10325476L;
sha_info->digest[4] = 0xc3d2e1f0L;
sha_info->count_lo = 0L;
sha_info->count_hi = 0L;
sha_info->local = 0;
}
/* 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[20], 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);
}
/*
* End of copied SHA code.
*
* ------------------------------------------------------------------------
*/
static PyTypeObject SHAtype;
static SHAobject *
newSHAobject(void)
{
return (SHAobject *)PyObject_New(SHAobject, &SHAtype);
}
/* Internal methods for a hashing object */
static void
SHA_dealloc(PyObject *ptr)
{
PyObject_Del(ptr);
}
/* External methods for a hashing object */
PyDoc_STRVAR(SHA_copy__doc__, "Return a copy of the hashing object.");
static PyObject *
SHA_copy(SHAobject *self, PyObject *args)
{
SHAobject *newobj;
if (!PyArg_ParseTuple(args, ":copy")) {
return NULL;
}
if ( (newobj = newSHAobject())==NULL)
return NULL;
SHAcopy(self, newobj);
return (PyObject *)newobj;
}
PyDoc_STRVAR(SHA_digest__doc__,
"Return the digest value as a string of binary data.");
static PyObject *
SHA_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, sizeof(digest));
}
PyDoc_STRVAR(SHA_hexdigest__doc__,
"Return the digest value as a string of hexadecimal digits.");
static PyObject *
SHA_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, sizeof(digest) * 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<sizeof(digest); 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(SHA_update__doc__,
"Update this hashing object's state with the provided string.");
static PyObject *
SHA_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)SHA_copy, METH_VARARGS, SHA_copy__doc__},
{"digest", (PyCFunction)SHA_digest, METH_VARARGS, SHA_digest__doc__},
{"hexdigest", (PyCFunction)SHA_hexdigest, METH_VARARGS, SHA_hexdigest__doc__},
{"update", (PyCFunction)SHA_update, METH_VARARGS, SHA_update__doc__},
{NULL, NULL} /* sentinel */
};
static PyObject *
SHA_get_block_size(PyObject *self, void *closure)
{
return PyInt_FromLong(SHA_BLOCKSIZE);
}
static PyObject *
SHA_get_digest_size(PyObject *self, void *closure)
{
return PyInt_FromLong(SHA_DIGESTSIZE);
}
static PyObject *
SHA_get_name(PyObject *self, void *closure)
{
return PyString_FromStringAndSize("SHA1", 4);
}
static PyGetSetDef SHA_getseters[] = {
{"digest_size",
(getter)SHA_get_digest_size, NULL,
NULL,
NULL},
{"block_size",
(getter)SHA_get_block_size, NULL,
NULL,
NULL},
{"name",
(getter)SHA_get_name, NULL,
NULL,
NULL},
/* the old md5 and sha modules support 'digest_size' as in PEP 247.
* the old sha module also supported 'digestsize'. ugh. */
{"digestsize",
(getter)SHA_get_digest_size, NULL,
NULL,
NULL},
{NULL} /* Sentinel */
};
static PyTypeObject SHAtype = {
PyObject_HEAD_INIT(NULL)
0, /*ob_size*/
"_sha.sha", /*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 */
0, /* tp_members */
SHA_getseters, /* tp_getset */
};
/* The single module-level function: new() */
PyDoc_STRVAR(SHA_new__doc__,
"Return a new SHA hashing object. An optional string argument\n\
may be provided; if present, this string will be automatically\n\
hashed.");
static PyObject *
SHA_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 = newSHAobject()) == NULL)
return NULL;
sha_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[] = {
{"new", (PyCFunction)SHA_new, METH_VARARGS|METH_KEYWORDS, SHA_new__doc__},
{NULL, NULL} /* Sentinel */
};
/* Initialize this module. */
#define insint(n,v) { PyModule_AddIntConstant(m,n,v); }
PyMODINIT_FUNC
init_sha(void)
{
PyObject *m;
SHAtype.ob_type = &PyType_Type;
if (PyType_Ready(&SHAtype) < 0)
return;
m = Py_InitModule("_sha", SHA_functions);
/* Add some symbolic constants to the module */
insint("blocksize", 1); /* For future use, in case some hash
functions require an integral number of
blocks */
insint("digestsize", 20);
insint("digest_size", 20);
}
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