/* sha512.c - SHA384 and SHA512 hash functions
 *	Copyright (C) 2003 Free Software Foundation, Inc.
 *
 * Please see below for more legal information!
 *
 * This file is part of GnuPG.
 *
 * GnuPG 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.
 *
 * GnuPG 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */


/*  Test vectors from FIPS-180-2:
 *
 *  "abc"
 * 384:
 *  CB00753F 45A35E8B B5A03D69 9AC65007 272C32AB 0EDED163
 *  1A8B605A 43FF5BED 8086072B A1E7CC23 58BAECA1 34C825A7
 * 512:
 *  DDAF35A1 93617ABA CC417349 AE204131 12E6FA4E 89A97EA2 0A9EEEE6 4B55D39A
 *  2192992A 274FC1A8 36BA3C23 A3FEEBBD 454D4423 643CE80E 2A9AC94F A54CA49F
 *
 *  "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu"
 * 384:
 *  09330C33 F71147E8 3D192FC7 82CD1B47 53111B17 3B3B05D2
 *  2FA08086 E3B0F712 FCC7C71A 557E2DB9 66C3E9FA 91746039
 * 512:
 *  8E959B75 DAE313DA 8CF4F728 14FC143F 8F7779C6 EB9F7FA1 7299AEAD B6889018
 *  501D289E 4900F7E4 331B99DE C4B5433A C7D329EE B6DD2654 5E96E55B 874BE909
 *
 *  "a" x 1000000
 * 384:
 *  9D0E1809 716474CB 086E834E 310A4A1C ED149E9C 00F24852
 *  7972CEC5 704C2A5B 07B8B3DC 38ECC4EB AE97DDD8 7F3D8985
 * 512:
 *  E718483D 0CE76964 4E2E42C7 BC15B463 8E1F98B1 3B204428 5632A803 AFA973EB
 *  DE0FF244 877EA60A 4CB0432C E577C31B EB009C5C 2C49AA2E 4EADB217 AD8CC09B
 */


#include <config.h>
#include <string.h>
#include "util.h"
#include "algorithms.h"


typedef struct {
    u64  h0,h1,h2,h3,h4,h5,h6,h7;
    u64  nblocks;
    byte buf[128];
    int  count;
} SHA512_CONTEXT;

static void
burn_stack (int bytes)
{
    char buf[128];

    wipememory(buf,sizeof buf);
    bytes -= sizeof buf;
    if (bytes > 0)
        burn_stack (bytes);
}


void
sha512_init( SHA512_CONTEXT *hd )
{
    hd->h0 = 0x6a09e667f3bcc908;
    hd->h1 = 0xbb67ae8584caa73b;
    hd->h2 = 0x3c6ef372fe94f82b;
    hd->h3 = 0xa54ff53a5f1d36f1;
    hd->h4 = 0x510e527fade682d1;
    hd->h5 = 0x9b05688c2b3e6c1f;
    hd->h6 = 0x1f83d9abfb41bd6b;
    hd->h7 = 0x5be0cd19137e2179;

    hd->nblocks = 0;
    hd->count = 0;
}

void
sha384_init( SHA512_CONTEXT *hd )
{
  hd->h0 = 0xcbbb9d5dc1059ed8;
  hd->h1 = 0x629a292a367cd507;
  hd->h2 = 0x9159015a3070dd17;
  hd->h3 = 0x152fecd8f70e5939;
  hd->h4 = 0x67332667ffc00b31;
  hd->h5 = 0x8eb44a8768581511;
  hd->h6 = 0xdb0c2e0d64f98fa7;
  hd->h7 = 0x47b5481dbefa4fa4;

  hd->nblocks = 0;
  hd->count = 0;
}


/****************
 * Transform the message W which consists of 16 64-bit-words
 */
static void
transform( SHA512_CONTEXT *hd, byte *data )
{
  u64 a,b,c,d,e,f,g,h;
  u64 w[80];
  int t;
  static const u64 k[]=
    {
      0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f,
      0xe9b5dba58189dbbc, 0x3956c25bf348b538, 0x59f111f1b605d019,
      0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 0xd807aa98a3030242,
      0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2,
      0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235,
      0xc19bf174cf692694, 0xe49b69c19ef14ad2, 0xefbe4786384f25e3,
      0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65, 0x2de92c6f592b0275,
      0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
      0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f,
      0xbf597fc7beef0ee4, 0xc6e00bf33da88fc2, 0xd5a79147930aa725,
      0x06ca6351e003826f, 0x142929670a0e6e70, 0x27b70a8546d22ffc,
      0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df,
      0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6,
      0x92722c851482353b, 0xa2bfe8a14cf10364, 0xa81a664bbc423001,
      0xc24b8b70d0f89791, 0xc76c51a30654be30, 0xd192e819d6ef5218,
      0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8,
      0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99,
      0x34b0bcb5e19b48a8, 0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb,
      0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3, 0x748f82ee5defb2fc,
      0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
      0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915,
      0xc67178f2e372532b, 0xca273eceea26619c, 0xd186b8c721c0c207,
      0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178, 0x06f067aa72176fba,
      0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b,
      0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc,
      0x431d67c49c100d4c, 0x4cc5d4becb3e42b6, 0x597f299cfc657e2a,
      0x5fcb6fab3ad6faec, 0x6c44198c4a475817
    };

  /* get values from the chaining vars */
  a = hd->h0;
  b = hd->h1;
  c = hd->h2;
  d = hd->h3;
  e = hd->h4;
  f = hd->h5;
  g = hd->h6;
  h = hd->h7;

#ifdef BIG_ENDIAN_HOST
  memcpy( w, data, 128 );
#else
  {
    int i;
    byte *p2;

    for(i=0, p2=(byte*)w; i < 16; i++, p2 += 8 )
      {
	p2[7] = *data++;
	p2[6] = *data++;
	p2[5] = *data++;
	p2[4] = *data++;
	p2[3] = *data++;
	p2[2] = *data++;
	p2[1] = *data++;
	p2[0] = *data++;
      }
  }
#endif

#define ROTR(x,n) (((x)>>(n)) | ((x)<<(64-(n))))
#define Ch(x,y,z) (((x) & (y)) ^ ((~(x)) & (z)))
#define Maj(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
#define Sum0(x) (ROTR((x),28) ^ ROTR((x),34) ^ ROTR((x),39))
#define Sum1(x) (ROTR((x),14) ^ ROTR((x),18) ^ ROTR((x),41))
#define S0(x) (ROTR((x),1) ^ ROTR((x),8) ^ ((x)>>7))
#define S1(x) (ROTR((x),19) ^ ROTR((x),61) ^ ((x)>>6))

  for(t=16;t<80;t++)
    w[t] = S1(w[t-2]) + w[t-7] + S0(w[t-15]) + w[t-16];

  for(t=0;t<80;t++)
    {
      u64 t1,t2;

      t1=h+Sum1(e)+Ch(e,f,g)+k[t]+w[t];
      t2=Sum0(a)+Maj(a,b,c);
      h=g;
      g=f;
      f=e;
      e=d+t1;
      d=c;
      c=b;
      b=a;
      a=t1+t2;

      /* printf("t=%d a=%016llX b=%016llX c=%016llX d=%016llX e=%016llX f=%016llX g=%016llX h=%016llX\n",t,a,b,c,d,e,f,g,h); */
    }

  /* update chaining vars */
  hd->h0 += a;
  hd->h1 += b;
  hd->h2 += c;
  hd->h3 += d;
  hd->h4 += e;
  hd->h5 += f;
  hd->h6 += g;
  hd->h7 += h;
}


/* Update the message digest with the contents
 * of INBUF with length INLEN.
 */
static void
sha512_write( SHA512_CONTEXT *hd, byte *inbuf, size_t inlen)
{
    if( hd->count == 128 ) { /* flush the buffer */
	transform( hd, hd->buf );
        burn_stack (768);
	hd->count = 0;
	hd->nblocks++;
    }
    if( !inbuf )
	return;
    if( hd->count ) {
	for( ; inlen && hd->count < 128; inlen-- )
	    hd->buf[hd->count++] = *inbuf++;
	sha512_write( hd, NULL, 0 );
	if( !inlen )
	    return;
    }

    while( inlen >= 128 ) {
	transform( hd, inbuf );
	hd->count = 0;
	hd->nblocks++;
	inlen -= 128;
	inbuf += 128;
    }
    burn_stack (768);
    for( ; inlen && hd->count < 128; inlen-- )
	hd->buf[hd->count++] = *inbuf++;
}


/* The routine final terminates the computation and
 * returns the digest.
 * The handle is prepared for a new cycle, but adding bytes to the
 * handle will the destroy the returned buffer.
 * Returns: 64 bytes representing the digest.  When used for sha384,
 * we take the leftmost 48 of those bytes.
 */

static void
sha512_final(SHA512_CONTEXT *hd)
{
    u64 t, msb, lsb;
    byte *p;

    sha512_write(hd, NULL, 0); /* flush */;

    t = hd->nblocks;
    /* multiply by 128 to make a byte count */
    lsb = t << 7;
    msb = t >> 57;
    /* add the count */
    t = lsb;
    if( (lsb += hd->count) < t )
	msb++;
    /* multiply by 8 to make a bit count */
    t = lsb;
    lsb <<= 3;
    msb <<= 3;
    msb |= t >> 61;

    if( hd->count < 112 ) { /* enough room */
	hd->buf[hd->count++] = 0x80; /* pad */
	while( hd->count < 112 )
	    hd->buf[hd->count++] = 0;  /* pad */
    }
    else { /* need one extra block */
	hd->buf[hd->count++] = 0x80; /* pad character */
	while( hd->count < 128 )
	    hd->buf[hd->count++] = 0;
	sha512_write(hd, NULL, 0);  /* flush */;
	memset(hd->buf, 0, 112 ); /* fill next block with zeroes */
    }
    /* append the 128 bit count */
    hd->buf[112] = msb >> 56;
    hd->buf[113] = msb >> 48;
    hd->buf[114] = msb >> 40;
    hd->buf[115] = msb >> 32;
    hd->buf[116] = msb >> 24;
    hd->buf[117] = msb >> 16;
    hd->buf[118] = msb >>  8;
    hd->buf[119] = msb	   ;

    hd->buf[120] = lsb >> 56;
    hd->buf[121] = lsb >> 48;
    hd->buf[122] = lsb >> 40;
    hd->buf[123] = lsb >> 32;
    hd->buf[124] = lsb >> 24;
    hd->buf[125] = lsb >> 16;
    hd->buf[126] = lsb >>  8;
    hd->buf[127] = lsb	   ;
    transform( hd, hd->buf );
    burn_stack (768);

    p = hd->buf;
  #ifdef BIG_ENDIAN_HOST
    #define X(a) do { *(u64*)p = hd->h##a ; p += 8; } while(0)
  #else /* little endian */
    #define X(a) do { *p++ = hd->h##a >> 56; *p++ = hd->h##a >> 48;	 \
                      *p++ = hd->h##a >> 40; *p++ = hd->h##a >> 32;	 \
                      *p++ = hd->h##a >> 24; *p++ = hd->h##a >> 16;	 \
		      *p++ = hd->h##a >> 8; *p++ = hd->h##a; } while(0)
  #endif
    X(0);
    X(1);
    X(2);
    X(3);
    X(4);
    X(5);
    /* Note that these last two chunks are included even for SHA384.
       We just ignore them. */
    X(6);
    X(7);
  #undef X
}

static byte *
sha512_read( SHA512_CONTEXT *hd )
{
    return hd->buf;
}

/****************
 * Return some information about the algorithm.  We need algo here to
 * distinguish different flavors of the algorithm.
 * Returns: A pointer to string describing the algorithm or NULL if
 *	    the ALGO is invalid.
 */
const char *
sha512_get_info( int algo, size_t *contextsize,
		 byte **r_asnoid, int *r_asnlen, int *r_mdlen,
		 void (**r_init)( void *c ),
		 void (**r_write)( void *c, byte *buf, size_t nbytes ),
		 void (**r_final)( void *c ),
		 byte *(**r_read)( void *c )
		 )
{
  static byte asn[] = /* Object ID is 2.16.840.1.101.3.4.2.3 */
    { 
      0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
      0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05,
      0x00, 0x04, 0x40
    };

    if( algo != 10 )
	return NULL;

    *contextsize = sizeof(SHA512_CONTEXT);
    *r_asnoid = asn;
    *r_asnlen = DIM(asn);
    *r_mdlen = 64;
    *(void  (**)(SHA512_CONTEXT *))r_init 	  	  = sha512_init;
    *(void  (**)(SHA512_CONTEXT *, byte*, size_t))r_write = sha512_write;
    *(void  (**)(SHA512_CONTEXT *))r_final		  = sha512_final;
    *(byte *(**)(SHA512_CONTEXT *))r_read 		  = sha512_read;

    return "SHA512";
}

/* SHA384 is really a truncated SHA512 with a different
   initialization */
const char *
sha384_get_info( int algo, size_t *contextsize,
		 byte **r_asnoid, int *r_asnlen, int *r_mdlen,
		 void (**r_init)( void *c ),
		 void (**r_write)( void *c, byte *buf, size_t nbytes ),
		 void (**r_final)( void *c ),
		 byte *(**r_read)( void *c )
		 )
{
  static byte asn[] = /* Object ID is 2.16.840.1.101.3.4.2.2 */
    {
      0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
      0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05,
      0x00, 0x04, 0x30
    };

    if( algo != 9 )
	return NULL;

    *contextsize = sizeof(SHA512_CONTEXT);
    *r_asnoid = asn;
    *r_asnlen = DIM(asn);
    *r_mdlen = 48;
    *(void  (**)(SHA512_CONTEXT *))r_init 	  	  = sha384_init;
    *(void  (**)(SHA512_CONTEXT *, byte*, size_t))r_write = sha512_write;
    *(void  (**)(SHA512_CONTEXT *))r_final		  = sha512_final;
    *(byte *(**)(SHA512_CONTEXT *))r_read 		  = sha512_read;

    return "SHA384";
}