dbus-sha.c
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-sha.c SHA-1 implementation
*
* Copyright (C) 2003 Red Hat Inc.
* Copyright (C) 1995 A. M. Kuchling
* SPDX-License-Identifier: (AFL-2.1 OR GPL-2.0-or-later) AND LicenseRef-pycrypto-orig
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include "dbus-internals.h"
#include "dbus-sha.h"
#include "dbus-marshal-basic.h" /* for byteswap routines */
#include <string.h>
/* The following comments have the history of where this code
* comes from. I actually copied it from GNet in GNOME CVS.
* - hp@redhat.com
*/
/*
* sha.h : Implementation of the Secure Hash Algorithm
*
* Part of the Python Cryptography Toolkit, version 1.0.0
*
* Copyright (C) 1995, A.M. Kuchling
*
* Distribute and use freely; there are no restrictions on further
* dissemination and usage except those imposed by the laws of your
* country of residence.
*
*/
/* SHA: NIST's Secure Hash Algorithm */
/* Based on SHA code originally posted to sci.crypt by Peter Gutmann
in message <30ajo5$oe8@ccu2.auckland.ac.nz>.
Modified to test for endianness on creation of SHA objects by AMK.
Also, the original specification of SHA was found to have a weakness
by NSA/NIST. This code implements the fixed version of SHA.
*/
/* Here's the first paragraph of Peter Gutmann's posting:
The following is my SHA (FIPS 180) code updated to allow use of the "fixed"
SHA, thanks to Jim Gillogly and an anonymous contributor for the information on
what's changed in the new version. The fix is a simple change which involves
adding a single rotate in the initial expansion function. It is unknown
whether this is an optimal solution to the problem which was discovered in the
SHA or whether it's simply a bandaid which fixes the problem with a minimum of
effort (for example the reengineering of a great many Capstone chips).
*/
#ifndef DOXYGEN_SHOULD_SKIP_THIS
/* The SHA block size and message digest sizes, in bytes */
#define SHA_DATASIZE 64
#define SHA_DIGESTSIZE 20
/* 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 */
/* The SHA Mysterious Constants */
#define K1 0x5A827999L /* Rounds 0-19 */
#define K2 0x6ED9EBA1L /* Rounds 20-39 */
#define K3 0x8F1BBCDCL /* Rounds 40-59 */
#define K4 0xCA62C1D6L /* Rounds 60-79 */
/* SHA initial values */
#define h0init 0x67452301L
#define h1init 0xEFCDAB89L
#define h2init 0x98BADCFEL
#define h3init 0x10325476L
#define h4init 0xC3D2E1F0L
/* Note that it may be necessary to add parentheses to these macros if they
are to be called with expressions as arguments */
/* 32-bit rotate left - kludged with shifts */
#define ROTL(n,X) ( ( ( X ) << n ) | ( ( X ) >> ( 32 - n ) ) )
/* The initial expanding function. The hash function is defined over an
80-word expanded input array W, where the first 16 are copies of the input
data, and the remaining 64 are defined by
W[ i ] = W[ i - 16 ] ^ W[ i - 14 ] ^ W[ i - 8 ] ^ W[ i - 3 ]
This implementation generates these values on the fly in a circular
buffer - thanks to Colin Plumb, colin@nyx10.cs.du.edu for this
optimization.
The updated SHA changes the expanding function by adding a rotate of 1
bit. Thanks to Jim Gillogly, jim@rand.org, and an anonymous contributor
for this information */
#define expand(W,i) ( W[ i & 15 ] = ROTL( 1, ( W[ i & 15 ] ^ W[ (i - 14) & 15 ] ^ \
W[ (i - 8) & 15 ] ^ W[ (i - 3) & 15 ] ) ) )
/* The prototype SHA sub-round. The fundamental sub-round is:
a' = e + ROTL( 5, a ) + f( b, c, d ) + k + data;
b' = a;
c' = ROTL( 30, b );
d' = c;
e' = d;
but this is implemented by unrolling the loop 5 times and renaming the
variables ( e, a, b, c, d ) = ( a', b', c', d', e' ) each iteration.
This code is then replicated 20 times for each of the 4 functions, using
the next 20 values from the W[] array each time */
#define subRound(a, b, c, d, e, f, k, data) \
( e += ROTL( 5, a ) + f( b, c, d ) + k + data, b = ROTL( 30, b ) )
#endif /* !DOXYGEN_SHOULD_SKIP_THIS */
/* Perform the SHA transformation. Note that this code, like MD5, seems to
break some optimizing compilers due to the complexity of the expressions
and the size of the basic block. It may be necessary to split it into
sections, e.g. based on the four subrounds
Note that this corrupts the context->data area */
static void
SHATransform(dbus_uint32_t *digest, dbus_uint32_t *data)
{
dbus_uint32_t A, B, C, D, E; /* Local vars */
dbus_uint32_t eData[16]; /* Expanded data */
/* Set up first buffer and local data buffer */
A = digest[0];
B = digest[1];
C = digest[2];
D = digest[3];
E = digest[4];
memmove (eData, data, SHA_DATASIZE);
/* Heavy mangling, in 4 sub-rounds of 20 interations each. */
subRound (A, B, C, D, E, f1, K1, eData[0]);
subRound (E, A, B, C, D, f1, K1, eData[1]);
subRound (D, E, A, B, C, f1, K1, eData[2]);
subRound (C, D, E, A, B, f1, K1, eData[3]);
subRound (B, C, D, E, A, f1, K1, eData[4]);
subRound (A, B, C, D, E, f1, K1, eData[5]);
subRound (E, A, B, C, D, f1, K1, eData[6]);
subRound (D, E, A, B, C, f1, K1, eData[7]);
subRound (C, D, E, A, B, f1, K1, eData[8]);
subRound (B, C, D, E, A, f1, K1, eData[9]);
subRound (A, B, C, D, E, f1, K1, eData[10]);
subRound (E, A, B, C, D, f1, K1, eData[11]);
subRound (D, E, A, B, C, f1, K1, eData[12]);
subRound (C, D, E, A, B, f1, K1, eData[13]);
subRound (B, C, D, E, A, f1, K1, eData[14]);
subRound (A, B, C, D, E, f1, K1, eData[15]);
subRound (E, A, B, C, D, f1, K1, expand ( eData, 16) );
subRound (D, E, A, B, C, f1, K1, expand ( eData, 17) );
subRound (C, D, E, A, B, f1, K1, expand ( eData, 18) );
subRound (B, C, D, E, A, f1, K1, expand ( eData, 19) );
subRound (A, B, C, D, E, f2, K2, expand ( eData, 20) );
subRound (E, A, B, C, D, f2, K2, expand ( eData, 21) );
subRound (D, E, A, B, C, f2, K2, expand ( eData, 22) );
subRound (C, D, E, A, B, f2, K2, expand ( eData, 23) );
subRound (B, C, D, E, A, f2, K2, expand ( eData, 24) );
subRound (A, B, C, D, E, f2, K2, expand ( eData, 25) );
subRound (E, A, B, C, D, f2, K2, expand ( eData, 26) );
subRound (D, E, A, B, C, f2, K2, expand ( eData, 27) );
subRound (C, D, E, A, B, f2, K2, expand ( eData, 28) );
subRound (B, C, D, E, A, f2, K2, expand ( eData, 29) );
subRound (A, B, C, D, E, f2, K2, expand ( eData, 30) );
subRound (E, A, B, C, D, f2, K2, expand ( eData, 31) );
subRound (D, E, A, B, C, f2, K2, expand ( eData, 32) );
subRound (C, D, E, A, B, f2, K2, expand ( eData, 33) );
subRound (B, C, D, E, A, f2, K2, expand ( eData, 34) );
subRound (A, B, C, D, E, f2, K2, expand ( eData, 35) );
subRound (E, A, B, C, D, f2, K2, expand ( eData, 36) );
subRound (D, E, A, B, C, f2, K2, expand ( eData, 37) );
subRound (C, D, E, A, B, f2, K2, expand ( eData, 38) );
subRound (B, C, D, E, A, f2, K2, expand ( eData, 39) );
subRound (A, B, C, D, E, f3, K3, expand ( eData, 40) );
subRound (E, A, B, C, D, f3, K3, expand ( eData, 41) );
subRound (D, E, A, B, C, f3, K3, expand ( eData, 42) );
subRound (C, D, E, A, B, f3, K3, expand ( eData, 43) );
subRound (B, C, D, E, A, f3, K3, expand ( eData, 44) );
subRound (A, B, C, D, E, f3, K3, expand ( eData, 45) );
subRound (E, A, B, C, D, f3, K3, expand ( eData, 46) );
subRound (D, E, A, B, C, f3, K3, expand ( eData, 47) );
subRound (C, D, E, A, B, f3, K3, expand ( eData, 48) );
subRound (B, C, D, E, A, f3, K3, expand ( eData, 49) );
subRound (A, B, C, D, E, f3, K3, expand ( eData, 50) );
subRound (E, A, B, C, D, f3, K3, expand ( eData, 51) );
subRound (D, E, A, B, C, f3, K3, expand ( eData, 52) );
subRound (C, D, E, A, B, f3, K3, expand ( eData, 53) );
subRound (B, C, D, E, A, f3, K3, expand ( eData, 54) );
subRound (A, B, C, D, E, f3, K3, expand ( eData, 55) );
subRound (E, A, B, C, D, f3, K3, expand ( eData, 56) );
subRound (D, E, A, B, C, f3, K3, expand ( eData, 57) );
subRound (C, D, E, A, B, f3, K3, expand ( eData, 58) );
subRound (B, C, D, E, A, f3, K3, expand ( eData, 59) );
subRound (A, B, C, D, E, f4, K4, expand ( eData, 60) );
subRound (E, A, B, C, D, f4, K4, expand ( eData, 61) );
subRound (D, E, A, B, C, f4, K4, expand ( eData, 62) );
subRound (C, D, E, A, B, f4, K4, expand ( eData, 63) );
subRound (B, C, D, E, A, f4, K4, expand ( eData, 64) );
subRound (A, B, C, D, E, f4, K4, expand ( eData, 65) );
subRound (E, A, B, C, D, f4, K4, expand ( eData, 66) );
subRound (D, E, A, B, C, f4, K4, expand ( eData, 67) );
subRound (C, D, E, A, B, f4, K4, expand ( eData, 68) );
subRound (B, C, D, E, A, f4, K4, expand ( eData, 69) );
subRound (A, B, C, D, E, f4, K4, expand ( eData, 70) );
subRound (E, A, B, C, D, f4, K4, expand ( eData, 71) );
subRound (D, E, A, B, C, f4, K4, expand ( eData, 72) );
subRound (C, D, E, A, B, f4, K4, expand ( eData, 73) );
subRound (B, C, D, E, A, f4, K4, expand ( eData, 74) );
subRound (A, B, C, D, E, f4, K4, expand ( eData, 75) );
subRound (E, A, B, C, D, f4, K4, expand ( eData, 76) );
subRound (D, E, A, B, C, f4, K4, expand ( eData, 77) );
subRound (C, D, E, A, B, f4, K4, expand ( eData, 78) );
subRound (B, C, D, E, A, f4, K4, expand ( eData, 79) );
/* Build message digest */
digest[0] += A;
digest[1] += B;
digest[2] += C;
digest[3] += D;
digest[4] += E;
}
/* When run on a little-endian CPU we need to perform byte reversal on an
array of longwords. */
#ifdef WORDS_BIGENDIAN
#define swap_words(buffer, byte_count)
#else
static void
swap_words (dbus_uint32_t *buffer,
int byte_count)
{
byte_count /= sizeof (dbus_uint32_t);
while (byte_count--)
{
*buffer = DBUS_UINT32_SWAP_LE_BE (*buffer);
++buffer;
}
}
#endif
static void
sha_init (DBusSHAContext *context)
{
/* Set the h-vars to their initial values */
context->digest[0] = h0init;
context->digest[1] = h1init;
context->digest[2] = h2init;
context->digest[3] = h3init;
context->digest[4] = h4init;
/* Initialise bit count */
context->count_lo = context->count_hi = 0;
}
static void
sha_append (DBusSHAContext *context,
const unsigned char *buffer,
unsigned int count)
{
dbus_uint32_t tmp;
unsigned int dataCount;
/* Update bitcount */
tmp = context->count_lo;
if (( context->count_lo = tmp + ( ( dbus_uint32_t) count << 3) ) < tmp)
context->count_hi++; /* Carry from low to high */
context->count_hi += count >> 29;
/* Get count of bytes already in data */
dataCount = (int) (tmp >> 3) & 0x3F;
/* Handle any leading odd-sized chunks */
if (dataCount)
{
unsigned char *p = (unsigned char *) context->data + dataCount;
dataCount = SHA_DATASIZE - dataCount;
if (count < dataCount)
{
memmove (p, buffer, count);
return;
}
memmove (p, buffer, dataCount);
swap_words (context->data, SHA_DATASIZE);
SHATransform (context->digest, context->data);
buffer += dataCount;
count -= dataCount;
}
/* Process data in SHA_DATASIZE chunks */
while (count >= SHA_DATASIZE)
{
memmove (context->data, buffer, SHA_DATASIZE);
swap_words (context->data, SHA_DATASIZE);
SHATransform (context->digest, context->data);
buffer += SHA_DATASIZE;
count -= SHA_DATASIZE;
}
/* Handle any remaining bytes of data. */
memmove (context->data, buffer, count);
}
/* Final wrapup - pad to SHA_DATASIZE-byte boundary with the bit pattern
1 0* (64-bit count of bits processed, MSB-first) */
static void
sha_finish (DBusSHAContext *context, unsigned char digest[20])
{
int count;
unsigned char *data_p;
/* Compute number of bytes mod 64 */
count = (int) context->count_lo;
count = (count >> 3) & 0x3F;
/* Set the first char of padding to 0x80. This is safe since there is
always at least one byte free */
data_p = (unsigned char *) context->data + count;
*data_p++ = 0x80;
/* Bytes of padding needed to make 64 bytes */
count = SHA_DATASIZE - 1 - count;
/* Pad out to 56 mod 64 */
if (count < 8)
{
/* Two lots of padding: Pad the first block to 64 bytes */
memset (data_p, 0, count);
swap_words (context->data, SHA_DATASIZE);
SHATransform (context->digest, context->data);
/* Now fill the next block with 56 bytes */
memset (context->data, 0, SHA_DATASIZE - 8);
}
else
/* Pad block to 56 bytes */
memset (data_p, 0, count - 8);
/* Append length in bits and transform */
context->data[14] = context->count_hi;
context->data[15] = context->count_lo;
swap_words (context->data, SHA_DATASIZE - 8);
SHATransform (context->digest, context->data);
swap_words (context->digest, SHA_DIGESTSIZE);
memmove (digest, context->digest, SHA_DIGESTSIZE);
}
/* End of internals */
void
_dbus_sha_init (DBusSHAContext *context)
{
sha_init (context);
}
void
_dbus_sha_update (DBusSHAContext *context,
const DBusString *data)
{
unsigned int inputLen;
const unsigned char *input;
input = (const unsigned char*) _dbus_string_get_const_data (data);
inputLen = _dbus_string_get_length (data);
sha_append (context, input, inputLen);
}
dbus_bool_t
_dbus_sha_final (DBusSHAContext *context,
DBusString *results)
{
unsigned char digest[20];
sha_finish (context, digest);
if (!_dbus_string_append_len (results, (const char *) digest, 20))
return FALSE;
/* some kind of security paranoia, though it seems pointless
* to me given the nonzeroed stuff flying around
*/
_DBUS_ZERO(*context);
return TRUE;
}
dbus_bool_t
_dbus_sha_compute (const DBusString *data,
DBusString *ascii_output)
{
DBusSHAContext context;
DBusString digest;
_dbus_sha_init (&context);
_dbus_sha_update (&context, data);
if (!_dbus_string_init (&digest))
return FALSE;
if (!_dbus_sha_final (&context, &digest))
goto error;
if (!_dbus_string_hex_encode (&digest, 0, ascii_output,
_dbus_string_get_length (ascii_output)))
goto error;
_dbus_string_free (&digest);
return TRUE;
error:
_dbus_string_free (&digest);
return FALSE;
}
/* end of exported functions */
_DBUS_ZERO
#define _DBUS_ZERO(object)
Sets all bits in an object to zero.
Definition dbus-internals.h:194
TRUE
#define TRUE
Expands to "1".
Definition dbus-macros.h:41
FALSE
#define FALSE
Expands to "0".
Definition dbus-macros.h:44
_dbus_sha_compute
dbus_bool_t _dbus_sha_compute(const DBusString *data, DBusString *ascii_output)
Computes the ASCII hex-encoded shasum of the given data and appends it to the output string.
Definition dbus-sha.c:484
_dbus_sha_init
void _dbus_sha_init(DBusSHAContext *context)
Initializes the SHA context.
Definition dbus-sha.c:421
_dbus_sha_update
void _dbus_sha_update(DBusSHAContext *context, const DBusString *data)
Feeds more data into an existing shasum computation.
Definition dbus-sha.c:433
_dbus_sha_final
dbus_bool_t _dbus_sha_final(DBusSHAContext *context, DBusString *results)
SHA finalization.
Definition dbus-sha.c:457
_dbus_string_init
dbus_bool_t _dbus_string_init(DBusString *str)
Initializes a string.
Definition dbus-string.c:182
_dbus_string_append_len
dbus_bool_t _dbus_string_append_len(DBusString *str, const char *buffer, int len)
Appends block of bytes with the given length to a DBusString.
Definition dbus-string.c:1170
_dbus_string_free
void _dbus_string_free(DBusString *str)
Frees a string created by _dbus_string_init(), and fills it with the same contents as _DBUS_STRING_IN...
Definition dbus-string.c:278
_dbus_string_hex_encode
dbus_bool_t _dbus_string_hex_encode(const DBusString *source, int start, DBusString *dest, int insert_at)
Encodes a string in hex, the way MD5 and SHA-1 are usually encoded.
Definition dbus-string.c:2382
dbus_uint32_t
unsigned int dbus_uint32_t
A 32-bit unsigned integer on all platforms.
Definition dbus-arch-deps.h:45
dbus_bool_t
dbus_uint32_t dbus_bool_t
A boolean, valid values are TRUE and FALSE.
Definition dbus-types.h:37
DBusSHAContext
Struct storing state of the SHA algorithm.
Definition dbus-sha.h:40
DBusSHAContext::digest
dbus_uint32_t digest[5]
Message digest.
Definition dbus-sha.h:41
DBusSHAContext::data
dbus_uint32_t data[16]
SHA data buffer.
Definition dbus-sha.h:44
DBusSHAContext::count_lo
dbus_uint32_t count_lo
64-bit bit count
Definition dbus-sha.h:42
DBusSHAContext::count_hi
dbus_uint32_t count_hi
No clue.
Definition dbus-sha.h:43
DBusString
Definition dbus-string.h:47