///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// LibSha1
//
// Implementation of SHA1 hash function.
// Original author: Steve Reid <sreid@sea-to-sky.net>
// Contributions by: James H. Brown <jbrown@burgoyne.com>, Saul Kravitz <Saul.Kravitz@celera.com>,
// and Ralph Giles <giles@ghostscript.com>
// Modified by WaterJuice retaining Public Domain license.
//
// This is free and unencumbered software released into the public domain - June 2013 waterjuice.org
// Modified to stop symbols being exported for libselinux shared library - October 2015
// Richard Haines <richard_c_haines@btinternet.com>
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// IMPORTS
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#include "sha1.h"
#include "dso.h"
#include <memory.h>
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// TYPES
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
typedef union
{
uint8_t c [64];
uint32_t l [16];
} CHAR64LONG16;
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// INTERNAL FUNCTIONS
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
// blk0() and blk() perform the initial expand.
#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
|(rol(block->l[i],8)&0x00FF00FF))
#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) + blk0(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);
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// TransformFunction
//
// Hash a single 512-bit block. This is the core of the algorithm
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
static
void
TransformFunction
(
uint32_t state[5],
const uint8_t buffer[64]
)
{
uint32_t a;
uint32_t b;
uint32_t c;
uint32_t d;
uint32_t e;
uint8_t workspace[64];
CHAR64LONG16* block = (CHAR64LONG16*) workspace;
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;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// PUBLIC FUNCTIONS
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Sha1Initialise
//
// Initialises an SHA1 Context. Use this to initialise/reset a context.
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void hidden
Sha1Initialise
(
Sha1Context* 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] = 0;
Context->Count[1] = 0;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Sha1Update
//
// Adds data to the SHA1 context. This will process the data and update the internal state of the context. Keep on
// calling this function until all the data has been added. Then call Sha1Finalise to calculate the hash.
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void hidden
Sha1Update
(
Sha1Context* Context,
void* Buffer,
uint32_t BufferSize
)
{
uint32_t i;
uint32_t j;
j = (Context->Count[0] >> 3) & 63;
if( (Context->Count[0] += BufferSize << 3) < (BufferSize << 3) )
{
Context->Count[1]++;
}
Context->Count[1] += (BufferSize >> 29);
if( (j + BufferSize) > 63 )
{
i = 64 - j;
memcpy( &Context->Buffer[j], Buffer, i );
TransformFunction(Context->State, Context->Buffer);
for( ; i + 63 < BufferSize; i += 64 )
{
TransformFunction(Context->State, (uint8_t*)Buffer + i);
}
j = 0;
}
else
{
i = 0;
}
memcpy( &Context->Buffer[j], &((uint8_t*)Buffer)[i], BufferSize - i );
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Sha1Finalise
//
// Performs the final calculation of the hash and returns the digest (20 byte buffer containing 160bit hash). After
// calling this, Sha1Initialised must be used to reuse the context.
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
void hidden
Sha1Finalise
(
Sha1Context* Context,
SHA1_HASH* Digest
)
{
uint32_t i;
uint8_t finalcount[8];
for( i=0; i<8; i++ )
{
finalcount[i] = (unsigned char)((Context->Count[(i >= 4 ? 0 : 1)]
>> ((3-(i & 3)) * 8) ) & 255); // Endian independent
}
Sha1Update( Context, (uint8_t*)"\x80", 1 );
while( (Context->Count[0] & 504) != 448 )
{
Sha1Update( Context, (uint8_t*)"\0", 1 );
}
Sha1Update( Context, finalcount, 8 ); // Should cause a Sha1TransformFunction()
for( i=0; i<SHA1_HASH_SIZE; i++ )
{
Digest->bytes[i] = (uint8_t)((Context->State[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
}
}