updated sha1 to automatically detect endianess

This commit is contained in:
Arvid Norberg 2004-08-01 22:15:44 +00:00
parent 433b3fd27a
commit cf9bbf1f45
3 changed files with 327 additions and 14 deletions

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@ -56,7 +56,7 @@ SOURCES =
tracker_manager.cpp
http_tracker_connection.cpp
udp_tracker_connection.cpp
sha1.c
sha1.cpp
;
ZLIB_SOURCES =

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@ -34,21 +34,23 @@ POSSIBILITY OF SUCH DAMAGE.
#define TORRENT_HASHER_HPP_INCLUDED
#include <cassert>
#include <boost/cstdint.hpp>
// from sha1.cpp
struct SHA1_CTX
{
boost::uint32_t state[5];
boost::uint32_t count[2];
boost::uint8_t buffer[64];
};
void SHA1Init(SHA1_CTX* context);
void SHA1Update(SHA1_CTX* context, boost::uint8_t const* data, boost::uint32_t len);
void SHA1Final(SHA1_CTX* context, boost::uint8_t* digest);
extern "C"
{
typedef struct {
unsigned int state[5];
unsigned int count[2];
unsigned char buffer[64];
} SHA1_CTX;
/* from sha1.c */
void SHA1Init(SHA1_CTX* context);
void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int len);
void SHA1Final(unsigned char* digest, SHA1_CTX* context);
/* from zlib/adler32.c */
// from zlib/adler32.c
unsigned long adler32(unsigned long adler, const char* data, unsigned int len);
}
@ -90,7 +92,7 @@ namespace libtorrent
sha1_hash final()
{
sha1_hash digest;
SHA1Final(digest.begin(), &m_context);
SHA1Final(&m_context, digest.begin());
return digest;
}

311
src/sha1.cpp Executable file
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@ -0,0 +1,311 @@
/*
SHA-1 C++ conversion
original version:
SHA-1 in C
By Steve Reid <sreid@sea-to-sky.net>
100% Public Domain
changelog at the end of the file.
*/
#include <cstdio>
#include <cstring>
// if you don't want boost
// replace with
// #include <stdint.h>
#include <boost/cstdint.hpp>
using boost::int32_t;
using boost::uint32_t;
using boost::uint8_t;
struct SHA1_CTX
{
uint32_t state[5];
uint32_t count[2];
uint8_t buffer[64];
};
void SHA1Init(SHA1_CTX* context);
void SHA1Update(SHA1_CTX* context, uint8_t const* data, uint32_t len);
void SHA1Final(SHA1_CTX* context, uint8_t* digest);
namespace
{
union CHAR64LONG16
{
uint8_t c[64];
uint32_t l[16];
};
#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
// blk0() and blk() perform the initial expand.
// I got the idea of expanding during the round function from SSLeay
struct little_endian_blk0
{
static uint32_t apply(CHAR64LONG16* block, int i)
{
return block->l[i] = (rol(block->l[i],24)&0xFF00FF00)
| (rol(block->l[i],8)&0x00FF00FF);
}
};
struct big_endian_blk0
{
static uint32_t apply(CHAR64LONG16* block, int i)
{
return block->l[i];
}
};
#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
^block->l[(i+2)&15]^block->l[i&15],1))
// (R0+R1), R2, R3, R4 are the different operations used in SHA1
#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+BlkFun::apply(block, i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
// Hash a single 512-bit block. This is the core of the algorithm.
template <class BlkFun>
void SHA1Transform(uint32_t state[5], uint8_t const buffer[64])
{
uint32_t a, b, c, d, e;
CHAR64LONG16* block;
uint8_t workspace[64];
block = (CHAR64LONG16*)workspace;
std::memcpy(block, buffer, 64);
// Copy context->state[] to working vars
a = state[0];
b = state[1];
c = state[2];
d = state[3];
e = state[4];
// 4 rounds of 20 operations each. Loop unrolled.
R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
// Add the working vars back into context.state[]
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
state[4] += e;
// Wipe variables
a = b = c = d = e = 0;
}
void SHAPrintContext(SHA1_CTX *context, char *msg)
{
std::printf("%s (%d,%d) %x %x %x %x %x\n"
, msg, context->count[0], context->count[1]
, context->state[0], context->state[1]
, context->state[2], context->state[3]
, context->state[4]);
}
template <class BlkFun>
void internal_update(SHA1_CTX* context, uint8_t const* data, uint32_t len)
{
uint32_t i, j; // JHB
#ifdef VERBOSE
SHAPrintContext(context, "before");
#endif
j = (context->count[0] >> 3) & 63;
if ((context->count[0] += len << 3) < (len << 3)) context->count[1]++;
context->count[1] += (len >> 29);
if ((j + len) > 63)
{
std::memcpy(&context->buffer[j], data, (i = 64-j));
SHA1Transform<BlkFun>(context->state, context->buffer);
for ( ; i + 63 < len; i += 64)
{
SHA1Transform<BlkFun>(context->state, &data[i]);
}
j = 0;
}
else
{
i = 0;
}
std::memcpy(&context->buffer[j], &data[i], len - i);
#ifdef VERBOSE
SHAPrintContext(context, "after ");
#endif
}
bool is_big_endian()
{
uint32_t test = 1;
return *reinterpret_cast<uint8_t*>(&test) == 0;
}
}
// SHA1Init - Initialize new context
void SHA1Init(SHA1_CTX* context)
{
// SHA1 initialization constants
context->state[0] = 0x67452301;
context->state[1] = 0xEFCDAB89;
context->state[2] = 0x98BADCFE;
context->state[3] = 0x10325476;
context->state[4] = 0xC3D2E1F0;
context->count[0] = context->count[1] = 0;
}
// Run your data through this.
void SHA1Update(SHA1_CTX* context, uint8_t const* data, uint32_t len)
{
#if defined __BIG_ENDIAN__
internal_update<big_endian_blk0>(context, data, len);
#elif defined LITTLE_ENDIAN
internal_update<little_endian_blk0>(context, data, len);
#else
// select different functions depending on endianess
// and figure out the endianess runtime
if (is_big_endian())
internal_update<big_endian_blk0>(context, data, len);
else
internal_update<little_endian_blk0>(context, data, len);
#endif
}
// Add padding and return the message digest.
void SHA1Final(SHA1_CTX* context, uint8_t* digest)
{
uint8_t finalcount[8];
for (uint32_t i = 0; i < 8; ++i)
{
// Endian independent
finalcount[i] = static_cast<uint8_t>(
(context->count[(i >= 4 ? 0 : 1)]
>> ((3-(i & 3)) * 8) ) & 255);
}
SHA1Update(context, (uint8_t const*)"\200", 1);
while ((context->count[0] & 504) != 448)
SHA1Update(context, (uint8_t const*)"\0", 1);
SHA1Update(context, finalcount, 8); // Should cause a SHA1Transform()
for (uint32_t i = 0; i < 20; ++i)
{
digest[i] = static_cast<unsigned char>(
(context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
}
}
/************************************************************
-----------------
Modified 7/98
By James H. Brown <jbrown@burgoyne.com>
Still 100% Public Domain
Corrected a problem which generated improper hash values on 16 bit machines
Routine SHA1Update changed from
void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int
len)
to
void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned
long len)
The 'len' parameter was declared an int which works fine on 32 bit machines.
However, on 16 bit machines an int is too small for the shifts being done
against
it. This caused the hash function to generate incorrect values if len was
greater than 8191 (8K - 1) due to the 'len << 3' on line 3 of SHA1Update().
Since the file IO in main() reads 16K at a time, any file 8K or larger would
be guaranteed to generate the wrong hash (e.g. Test Vector #3, a million
"a"s).
I also changed the declaration of variables i & j in SHA1Update to
unsigned long from unsigned int for the same reason.
These changes should make no difference to any 32 bit implementations since
an
int and a long are the same size in those environments.
--
I also corrected a few compiler warnings generated by Borland C.
1. Added #include <process.h> for exit() prototype
2. Removed unused variable 'j' in SHA1Final
3. Changed exit(0) to return(0) at end of main.
ALL changes I made can be located by searching for comments containing 'JHB'
-----------------
Modified 8/98
By Steve Reid <sreid@sea-to-sky.net>
Still 100% public domain
1- Removed #include <process.h> and used return() instead of exit()
2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall)
3- Changed email address from steve@edmweb.com to sreid@sea-to-sky.net
-----------------
Modified 4/01
By Saul Kravitz <Saul.Kravitz@celera.com>
Still 100% PD
Modified to run on Compaq Alpha hardware.
-----------------
Converted to C++ 6/04
By Arvid Norberg <arvidn@sourceforge.net>
1- made the input buffer const, and made the
previous SHA1HANDSOFF implicit
2- uses C99 types with size guarantees
from boost
3- if none of __BIG_ENDIAN__ or LITTLE_ENDIAN
are defined, endianess is determined
at runtime. templates are used to duplicate
the transform function for each endianess
4- using anonymous namespace to avoid external
linkage on internal functions
5- using standard C++ includes
still 100% PD
*/
/*
Test Vectors (from FIPS PUB 180-1)
"abc"
A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D
"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"
84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1
A million repetitions of "a"
34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F
*/