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      1 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
      2 //  LibSha1
      3 //
      4 //  Implementation of SHA1 hash function.
      5 //  Original author:  Steve Reid <sreid (at) sea-to-sky.net>
      6 //  Contributions by: James H. Brown <jbrown (at) burgoyne.com>, Saul Kravitz <Saul.Kravitz (at) celera.com>,
      7 //  and Ralph Giles <giles (at) ghostscript.com>
      8 //  Modified by WaterJuice retaining Public Domain license.
      9 //
     10 //  This is free and unencumbered software released into the public domain - June 2013 waterjuice.org
     11 //  Modified to:
     12 //    - stop symbols being exported for libselinux shared library - October 2015
     13 //								       Richard Haines <richard_c_haines (at) btinternet.com>
     14 //    - Not cast the workspace from a byte array to a CHAR64LONG16 due to allignment isses.
     15 //      Fixes:
     16 //        sha1.c:73:33: error: cast from 'uint8_t *' (aka 'unsigned char *') to 'CHAR64LONG16 *' increases required alignment from 1 to 4 [-Werror,-Wcast-align]
     17 //             CHAR64LONG16*       block = (CHAR64LONG16*) workspace;
     18 //                                                                     William Roberts <william.c.roberts (at) intel.com>
     19 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     20 
     21 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     22 //  IMPORTS
     23 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     24 
     25 #include "sha1.h"
     26 #include "dso.h"
     27 #include <memory.h>
     28 
     29 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     30 //  TYPES
     31 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     32 
     33 typedef union
     34 {
     35     uint8_t     c [64];
     36     uint32_t    l [16];
     37 } CHAR64LONG16;
     38 
     39 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     40 //  INTERNAL FUNCTIONS
     41 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     42 
     43 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
     44 
     45 // blk0() and blk() perform the initial expand.
     46 #define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
     47     |(rol(block->l[i],8)&0x00FF00FF))
     48 
     49 #define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
     50     ^block->l[(i+2)&15]^block->l[i&15],1))
     51 
     52 // (R0+R1), R2, R3, R4 are the different operations used in SHA1
     53 #define R0(v,w,x,y,z,i)  z += ((w&(x^y))^y)     + blk0(i)+ 0x5A827999 + rol(v,5); w=rol(w,30);
     54 #define R1(v,w,x,y,z,i)  z += ((w&(x^y))^y)     + blk(i) + 0x5A827999 + rol(v,5); w=rol(w,30);
     55 #define R2(v,w,x,y,z,i)  z += (w^x^y)           + blk(i) + 0x6ED9EBA1 + rol(v,5); w=rol(w,30);
     56 #define R3(v,w,x,y,z,i)  z += (((w|x)&y)|(w&x)) + blk(i) + 0x8F1BBCDC + rol(v,5); w=rol(w,30);
     57 #define R4(v,w,x,y,z,i)  z += (w^x^y)           + blk(i) + 0xCA62C1D6 + rol(v,5); w=rol(w,30);
     58 
     59 
     60 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     61 //  TransformFunction
     62 //
     63 //  Hash a single 512-bit block. This is the core of the algorithm
     64 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     65 static
     66 void
     67     TransformFunction
     68     (
     69         uint32_t            state[5],
     70         const uint8_t       buffer[64]
     71     )
     72 {
     73     uint32_t            a;
     74     uint32_t            b;
     75     uint32_t            c;
     76     uint32_t            d;
     77     uint32_t            e;
     78     CHAR64LONG16        workspace;
     79     CHAR64LONG16*       block = &workspace;
     80 
     81     memcpy( block, buffer, 64 );
     82 
     83     // Copy context->state[] to working vars
     84     a = state[0];
     85     b = state[1];
     86     c = state[2];
     87     d = state[3];
     88     e = state[4];
     89 
     90     // 4 rounds of 20 operations each. Loop unrolled.
     91     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);
     92     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);
     93     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);
     94     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);
     95     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);
     96     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);
     97     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);
     98     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);
     99     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);
    100     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);
    101     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);
    102     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);
    103     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);
    104     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);
    105     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);
    106     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);
    107     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);
    108     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);
    109     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);
    110     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);
    111 
    112     // Add the working vars back into context.state[]
    113     state[0] += a;
    114     state[1] += b;
    115     state[2] += c;
    116     state[3] += d;
    117     state[4] += e;
    118 }
    119 
    120 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    121 //  PUBLIC FUNCTIONS
    122 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    123 
    124 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    125 //  Sha1Initialise
    126 //
    127 //  Initialises an SHA1 Context. Use this to initialise/reset a context.
    128 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    129 void hidden
    130     Sha1Initialise
    131     (
    132         Sha1Context*                Context
    133     )
    134 {
    135     // SHA1 initialization constants
    136     Context->State[0] = 0x67452301;
    137     Context->State[1] = 0xEFCDAB89;
    138     Context->State[2] = 0x98BADCFE;
    139     Context->State[3] = 0x10325476;
    140     Context->State[4] = 0xC3D2E1F0;
    141     Context->Count[0] = 0;
    142     Context->Count[1] = 0;
    143 }
    144 
    145 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    146 //  Sha1Update
    147 //
    148 //  Adds data to the SHA1 context. This will process the data and update the internal state of the context. Keep on
    149 //  calling this function until all the data has been added. Then call Sha1Finalise to calculate the hash.
    150 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    151 void hidden
    152     Sha1Update
    153     (
    154         Sha1Context*        Context,
    155         void*               Buffer,
    156         uint32_t            BufferSize
    157     )
    158 {
    159     uint32_t    i;
    160     uint32_t    j;
    161 
    162     j = (Context->Count[0] >> 3) & 63;
    163     if( (Context->Count[0] += BufferSize << 3) < (BufferSize << 3) )
    164     {
    165         Context->Count[1]++;
    166     }
    167 
    168     Context->Count[1] += (BufferSize >> 29);
    169     if( (j + BufferSize) > 63 )
    170     {
    171         i = 64 - j;
    172         memcpy( &Context->Buffer[j], Buffer, i );
    173         TransformFunction(Context->State, Context->Buffer);
    174         for( ; i + 63 < BufferSize; i += 64 )
    175         {
    176             TransformFunction(Context->State, (uint8_t*)Buffer + i);
    177         }
    178         j = 0;
    179     }
    180     else
    181     {
    182         i = 0;
    183     }
    184 
    185     memcpy( &Context->Buffer[j], &((uint8_t*)Buffer)[i], BufferSize - i );
    186 }
    187 
    188 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    189 //  Sha1Finalise
    190 //
    191 //  Performs the final calculation of the hash and returns the digest (20 byte buffer containing 160bit hash). After
    192 //  calling this, Sha1Initialised must be used to reuse the context.
    193 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    194 void hidden
    195     Sha1Finalise
    196     (
    197         Sha1Context*                Context,
    198         SHA1_HASH*                  Digest
    199     )
    200 {
    201     uint32_t    i;
    202     uint8_t     finalcount[8];
    203 
    204     for( i=0; i<8; i++ )
    205     {
    206         finalcount[i] = (unsigned char)((Context->Count[(i >= 4 ? 0 : 1)]
    207          >> ((3-(i & 3)) * 8) ) & 255);  // Endian independent
    208     }
    209     Sha1Update( Context, (uint8_t*)"\x80", 1 );
    210     while( (Context->Count[0] & 504) != 448 )
    211     {
    212         Sha1Update( Context, (uint8_t*)"\0", 1 );
    213     }
    214 
    215     Sha1Update( Context, finalcount, 8 );  // Should cause a Sha1TransformFunction()
    216     for( i=0; i<SHA1_HASH_SIZE; i++ )
    217     {
    218         Digest->bytes[i] = (uint8_t)((Context->State[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
    219     }
    220 }
    221