/* 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@krypto.org) | |
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, unsigned int count) | |
{ | |
unsigned 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 *unused) | |
{ | |
SHAobject *newobj; | |
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 *unused) | |
{ | |
unsigned char digest[SHA_DIGESTSIZE]; | |
SHAobject temp; | |
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 *unused) | |
{ | |
unsigned char digest[SHA_DIGESTSIZE]; | |
SHAobject temp; | |
PyObject *retval; | |
char *hex_digest; | |
int i, j; | |
/* 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) | |
{ | |
Py_buffer view; | |
Py_ssize_t n; | |
unsigned char *buf; | |
if (!PyArg_ParseTuple(args, "s*:update", &view)) | |
return NULL; | |
n = view.len; | |
buf = (unsigned char *) view.buf; | |
while (n > 0) { | |
Py_ssize_t nbytes; | |
if (n > INT_MAX) | |
nbytes = INT_MAX; | |
else | |
nbytes = n; | |
sha_update(self, buf, | |
Py_SAFE_DOWNCAST(nbytes, Py_ssize_t, unsigned int)); | |
buf += nbytes; | |
n -= nbytes; | |
} | |
PyBuffer_Release(&view); | |
Py_RETURN_NONE; | |
} | |
static PyMethodDef SHA_methods[] = { | |
{"copy", (PyCFunction)SHA_copy, METH_NOARGS, SHA_copy__doc__}, | |
{"digest", (PyCFunction)SHA_digest, METH_NOARGS, SHA_digest__doc__}, | |
{"hexdigest", (PyCFunction)SHA_hexdigest, METH_NOARGS, 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 = { | |
PyVarObject_HEAD_INIT(NULL, 0) | |
"_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; | |
Py_buffer view = { 0 }; | |
Py_ssize_t n; | |
unsigned char *buf; | |
if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s*:new", kwlist, | |
&view)) { | |
return NULL; | |
} | |
if ((new = newSHAobject()) == NULL) { | |
PyBuffer_Release(&view); | |
return NULL; | |
} | |
sha_init(new); | |
if (PyErr_Occurred()) { | |
Py_DECREF(new); | |
PyBuffer_Release(&view); | |
return NULL; | |
} | |
n = view.len; | |
buf = (unsigned char *) view.buf; | |
while (n > 0) { | |
Py_ssize_t nbytes; | |
if (n > INT_MAX) | |
nbytes = INT_MAX; | |
else | |
nbytes = n; | |
sha_update(new, buf, | |
Py_SAFE_DOWNCAST(nbytes, Py_ssize_t, unsigned int)); | |
buf += nbytes; | |
n -= nbytes; | |
} | |
PyBuffer_Release(&view); | |
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; | |
Py_TYPE(&SHAtype) = &PyType_Type; | |
if (PyType_Ready(&SHAtype) < 0) | |
return; | |
m = Py_InitModule("_sha", SHA_functions); | |
if (m == NULL) | |
return; | |
/* 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); | |
} |