OSX/libsecurity_cryptkit/lib/ckSHA1_priv.c

   1 /* Copyright (c) 1998,2011,2014 Apple Inc.  All Rights Reserved.
   2  *
   3  * NOTICE: USE OF THE MATERIALS ACCOMPANYING THIS NOTICE IS SUBJECT
   4  * TO THE TERMS OF THE SIGNED "FAST ELLIPTIC ENCRYPTION (FEE) REFERENCE
   5  * SOURCE CODE EVALUATION AGREEMENT" BETWEEN APPLE, INC. AND THE
   6  * ORIGINAL LICENSEE THAT OBTAINED THESE MATERIALS FROM APPLE,
   7  * INC.  ANY USE OF THESE MATERIALS NOT PERMITTED BY SUCH AGREEMENT WILL
   8  * EXPOSE YOU TO LIABILITY.
   9  ***************************************************************************
  10  *
  11  * ckSHA1_priv.c - low-level SHA-1 hash algorithm.
  12  *
  13  * Revision History
  14  * ----------------
  15  * 05 Jan 1998 at Apple
  16  *      Created, based on source by Peter C. Gutmann.
  17  *      Mods: made reentrant, added NIST fix to expand(), eliminated
  18  *      unnecessary copy to local W[] array.
  19  */
  20
  21
  22 /* NIST proposed Secure Hash Standard.
  23
  24    Written 2 September 1992, Peter C. Gutmann.
  25    This implementation placed in the public domain.
  26
  27    Comments to pgut1@cs.aukuni.ac.nz */
  28
  29 #include "ckconfig.h"
  30
  31 #if     !CRYPTKIT_LIBMD_DIGEST
  32
  33 #include "ckSHA1_priv.h"
  34 #include "platform.h"
  35 #include <string.h>
  36
  37 /* The SHS f()-functions */
  38
  39 #define f1(x,y,z)   ( ( x & y ) | ( ~x & z ) )              /* Rounds  0-19 */
  40 #define f2(x,y,z)   ( x ^ y ^ z )                           /* Rounds 20-39 */
  41 #define f3(x,y,z)   ( ( x & y ) | ( x & z ) | ( y & z ) )   /* Rounds 40-59 */
  42 #define f4(x,y,z)   ( x ^ y ^ z )                           /* Rounds 60-79 */
  43
  44 /* The SHS Mysterious Constants */
  45
  46 #define K1  0x5A827999L     /* Rounds  0-19 */
  47 #define K2  0x6ED9EBA1L     /* Rounds 20-39 */
  48 #define K3  0x8F1BBCDCL     /* Rounds 40-59 */
  49 #define K4  0xCA62C1D6L     /* Rounds 60-79 */
  50
  51 /* SHS initial values */
  52
  53 #define h0init  0x67452301L
  54 #define h1init  0xEFCDAB89L
  55 #define h2init  0x98BADCFEL
  56 #define h3init  0x10325476L
  57 #define h4init  0xC3D2E1F0L
  58
  59 /* 32-bit rotate - kludged with shifts */
  60
  61 #define S(n,X)  ( ( X << n ) | ( X >> ( 32 - n ) ) )
  62
  63 /* The initial expanding function */
  64
  65 /*
  66  * 06 Jan 1998. Added left circular shift per NIST FIPS-180-1 (at
  67  * http://www.nist.gov/itl/div897/pubs/fip180-1.htm). Also see
  68  * B. Schneier, Applied Cryptography, Second Edition, section 18.7
  69  * for info on this addenda to the original NIST spec.
  70  */
  71 #define expand(count) { \
  72     W[count] = W[count - 3] ^ W[count - 8] ^ W[count - 14] ^ W[count - 16]; \
  73     W[count] = S(1, W[count]); \
  74 }
  75
  76 /* The four SHS sub-rounds */
  77
  78 #define subRound1(count)    \
  79     { \
  80     temp = S( 5, A ) + f1( B, C, D ) + E + W[ count ] + K1; \
  81     E = D; \
  82     D = C; \
  83     C = S( 30, B ); \
  84     B = A; \
  85     A = temp; \
  86     }
  87
  88 #define subRound2(count)    \
  89     { \
  90     temp = S( 5, A ) + f2( B, C, D ) + E + W[ count ] + K2; \
  91     E = D; \
  92     D = C; \
  93     C = S( 30, B ); \
  94     B = A; \
  95     A = temp; \
  96     }
  97
  98 #define subRound3(count)    \
  99     { \
 100     temp = S( 5, A ) + f3( B, C, D ) + E + W[ count ] + K3; \
 101     E = D; \
 102     D = C; \
 103     C = S( 30, B ); \
 104     B = A; \
 105     A = temp; \
 106     }
 107
 108 #define subRound4(count)    \
 109     { \
 110     temp = S( 5, A ) + f4( B, C, D ) + E + W[ count ] + K4; \
 111     E = D; \
 112     D = C; \
 113     C = S( 30, B ); \
 114     B = A; \
 115     A = temp; \
 116     }
 117
 118 /* Initialize the SHS values */
 119
 120 void shsInit( SHS_INFO *shsInfo )
 121     {
 122     /* Set the h-vars to their initial values */
 123     shsInfo->digest[ 0 ] = h0init;
 124     shsInfo->digest[ 1 ] = h1init;
 125     shsInfo->digest[ 2 ] = h2init;
 126     shsInfo->digest[ 3 ] = h3init;
 127     shsInfo->digest[ 4 ] = h4init;
 128
 129     /* Initialise bit count */
 130     shsInfo->countLo = shsInfo->countHi = 0L;
 131     }
 132
 133 /* Perform the SHS transformation.  Note that this code, like MD5, seems to
 134    break some optimizing compilers - it may be necessary to split it into
 135    sections, eg based on the four subrounds */
 136
 137 static void shsTransform( SHS_INFO *shsInfo )
 138 {
 139     LONG *W, temp;
 140     LONG A, B, C, D, E;
 141
 142     /* Step A.  Copy the data buffer into the local work buffer. */
 143     /* 07 Jan 1998, dmitch: skip this bogus move, and let the caller
 144      * copy data directly into the W[] array. To minimize changes,
 145      * we'll just increase the size of shsInfo->data[] and make W
 146      * a pointer here.
 147      */
 148     W = shsInfo->data;
 149
 150     /* Step B.  Expand the 16 words into 64 temporary data words */
 151
 152     /*
 153      * Note: I tried optimizing this via a for loop, and for some reason,
 154      * the "optimized" version ran slower on PPC than the original
 155      * unrolled version. The optimized version does run faster on i486 than
 156      * the unrolled version.
 157      *
 158      * Similarly, the set of subRounds, below, runs slower on i486 when
 159      * optimized via 4 'for' loops. The "optimized" version of that is
 160      * a wash on PPC.
 161      *
 162      * Conclusion: leave both of 'em unrolled. We could ifdef per machine,
 163      * but this would get messy once we had more than two architectures.
 164      * We may want to revisit this.  --dpm
 165      */
 166     expand( 16 ); expand( 17 ); expand( 18 ); expand( 19 ); expand( 20 );
 167     expand( 21 ); expand( 22 ); expand( 23 ); expand( 24 ); expand( 25 );
 168     expand( 26 ); expand( 27 ); expand( 28 ); expand( 29 ); expand( 30 );
 169     expand( 31 ); expand( 32 ); expand( 33 ); expand( 34 ); expand( 35 );
 170     expand( 36 ); expand( 37 ); expand( 38 ); expand( 39 ); expand( 40 );
 171     expand( 41 ); expand( 42 ); expand( 43 ); expand( 44 ); expand( 45 );
 172     expand( 46 ); expand( 47 ); expand( 48 ); expand( 49 ); expand( 50 );
 173     expand( 51 ); expand( 52 ); expand( 53 ); expand( 54 ); expand( 55 );
 174     expand( 56 ); expand( 57 ); expand( 58 ); expand( 59 ); expand( 60 );
 175     expand( 61 ); expand( 62 ); expand( 63 ); expand( 64 ); expand( 65 );
 176     expand( 66 ); expand( 67 ); expand( 68 ); expand( 69 ); expand( 70 );
 177     expand( 71 ); expand( 72 ); expand( 73 ); expand( 74 ); expand( 75 );
 178     expand( 76 ); expand( 77 ); expand( 78 ); expand( 79 );
 179
 180     /* Step C.  Set up first buffer */
 181     A = shsInfo->digest[ 0 ];
 182     B = shsInfo->digest[ 1 ];
 183     C = shsInfo->digest[ 2 ];
 184     D = shsInfo->digest[ 3 ];
 185     E = shsInfo->digest[ 4 ];
 186
 187     /* Step D.  Serious mangling, divided into four sub-rounds */
 188     subRound1( 0 ); subRound1( 1 ); subRound1( 2 ); subRound1( 3 );
 189     subRound1( 4 ); subRound1( 5 ); subRound1( 6 ); subRound1( 7 );
 190     subRound1( 8 ); subRound1( 9 ); subRound1( 10 ); subRound1( 11 );
 191     subRound1( 12 ); subRound1( 13 ); subRound1( 14 ); subRound1( 15 );
 192     subRound1( 16 ); subRound1( 17 ); subRound1( 18 ); subRound1( 19 );
 193     subRound2( 20 ); subRound2( 21 ); subRound2( 22 ); subRound2( 23 );
 194     subRound2( 24 ); subRound2( 25 ); subRound2( 26 ); subRound2( 27 );
 195     subRound2( 28 ); subRound2( 29 ); subRound2( 30 ); subRound2( 31 );
 196     subRound2( 32 ); subRound2( 33 ); subRound2( 34 ); subRound2( 35 );
 197     subRound2( 36 ); subRound2( 37 ); subRound2( 38 ); subRound2( 39 );
 198     subRound3( 40 ); subRound3( 41 ); subRound3( 42 ); subRound3( 43 );
 199     subRound3( 44 ); subRound3( 45 ); subRound3( 46 ); subRound3( 47 );
 200     subRound3( 48 ); subRound3( 49 ); subRound3( 50 ); subRound3( 51 );
 201     subRound3( 52 ); subRound3( 53 ); subRound3( 54 ); subRound3( 55 );
 202     subRound3( 56 ); subRound3( 57 ); subRound3( 58 ); subRound3( 59 );
 203     subRound4( 60 ); subRound4( 61 ); subRound4( 62 ); subRound4( 63 );
 204     subRound4( 64 ); subRound4( 65 ); subRound4( 66 ); subRound4( 67 );
 205     subRound4( 68 ); subRound4( 69 ); subRound4( 70 ); subRound4( 71 );
 206     subRound4( 72 ); subRound4( 73 ); subRound4( 74 ); subRound4( 75 );
 207     subRound4( 76 ); subRound4( 77 ); subRound4( 78 ); subRound4( 79 );
 208
 209     /* Step E.  Build message digest */
 210     shsInfo->digest[ 0 ] += A;
 211     shsInfo->digest[ 1 ] += B;
 212     shsInfo->digest[ 2 ] += C;
 213     shsInfo->digest[ 3 ] += D;
 214     shsInfo->digest[ 4 ] += E;
 215 }
 216
 217 /* __LITTLE_ENDIAN__ is in fact #defined on OS X on  PPC.... */
 218 //#ifdef __LITTLE_ENDIAN__
 219 #if 0
 220
 221 /* When run on a little-endian CPU we need to perform byte reversal on an
 222    array of longwords.  It is possible to make the code endianness-
 223    independant by fiddling around with data at the byte level, but this
 224    makes for very slow code, so we rely on the user to sort out endianness
 225    at compile time */
 226
 227 static void byteReverse( buffer, byteCount )
 228   LONG *buffer;
 229   int byteCount;
 230
 231     {
 232     LONG value;
 233     int count;
 234
 235     byteCount /= sizeof( LONG );
 236     for( count = 0; count < byteCount; count++ )
 237         {
 238         value = ( buffer[ count ] << 16 ) | ( buffer[ count ] >> 16 );
 239         buffer[ count ] = ( ( value & 0xFF00FF00L ) >> 8 ) | ( ( value & 0x00FF00FFL ) << 8 );
 240         }
 241     }
 242
 243 #else   /* __LITTLE_ENDIAN__ */
 244
 245 /*
 246  * Nop for big-endian machines
 247  */
 248 #define byteReverse( buffer, byteCount )
 249
 250 #endif /* __LITTLE_ENDIAN__ */
 251
 252
 253 /* Update SHS for a block of data.  This code assumes that the buffer size
 254    is a multiple of SHS_BLOCKSIZE bytes long, which makes the code a lot
 255    more efficient since it does away with the need to handle partial blocks
 256    between calls to shsUpdate() */
 257
 258 void shsUpdate(
 259   SHS_INFO *shsInfo,
 260   const BYTE *buffer,
 261   int count)
 262
 263     {
 264     /* Update bitcount */
 265     if( ( shsInfo->countLo + ( ( LONG ) count << 3 ) ) < shsInfo->countLo )
 266         shsInfo->countHi++; /* Carry from low to high bitCount */
 267     shsInfo->countLo += ( ( LONG ) count << 3 );
 268     shsInfo->countHi += ( ( LONG ) count >> 29 );
 269
 270     /* Process data in SHS_BLOCKSIZE chunks */
 271     while( count >= SHS_BLOCKSIZE )
 272         {
 273         memcpy( shsInfo->data, buffer, SHS_BLOCKSIZE );
 274         byteReverse( shsInfo->data, SHS_BLOCKSIZE );
 275         shsTransform( shsInfo );
 276         buffer += SHS_BLOCKSIZE;
 277         count -= SHS_BLOCKSIZE;
 278         }
 279
 280     /* Handle any remaining bytes of data.  This should only happen once
 281        on the final lot of data */
 282     memcpy( shsInfo->data, buffer, count );
 283     }
 284
 285 void shsFinal(SHS_INFO *shsInfo)
 286     {
 287     int count;
 288     LONG lowBitcount = shsInfo->countLo, highBitcount = shsInfo->countHi;
 289
 290     /* Compute number of bytes mod 64 */
 291     count = ( int ) ( ( shsInfo->countLo >> 3 ) & 0x3F );
 292
 293     /* Set the first char of padding to 0x80.  This is safe since there is
 294        always at least one byte free */
 295     ( ( BYTE * ) shsInfo->data )[ count++ ] = 0x80;
 296
 297     /* Pad out to 56 mod 64 */
 298     if( count > 56 )
 299         {
 300         /* Two lots of padding:  Pad the first block to 64 bytes */
 301         memset( ( BYTE * ) &shsInfo->data + count, 0, 64 - count );
 302         byteReverse( shsInfo->data, SHS_BLOCKSIZE );
 303         shsTransform( shsInfo );
 304
 305         /* Now fill the next block with 56 bytes */
 306         memset( &shsInfo->data, 0, 56 );
 307         }
 308     else
 309         /* Pad block to 56 bytes */
 310         memset( ( BYTE * ) &shsInfo->data + count, 0, 56 - count );
 311         byteReverse( shsInfo->data, SHS_BLOCKSIZE );
 312
 313     /* Append length in bits and transform */
 314     shsInfo->data[ 14 ] = highBitcount;
 315     shsInfo->data[ 15 ] = lowBitcount;
 316
 317     shsTransform( shsInfo );
 318     byteReverse( shsInfo->data, SHS_DIGESTSIZE );
 319     }
 320
 321 #endif  /* CRYPTKIT_LIBMD_DIGEST */