bird/lib/sha1.c

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7 KiB
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/*
* BIRD Library -- SHA-1 Hash Function (FIPS 180-1, RFC 3174)
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*
* (c) 2015 CZ.NIC z.s.p.o.
*
* Based on the code from libucw-6.4
* (c) 2008--2009 Martin Mares <mj@ucw.cz>
*
* Based on the code from libgcrypt-1.2.3, which is
* (c) 1998, 2001, 2002, 2003 Free Software Foundation, Inc.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include "lib/sha1.h"
#include "lib/unaligned.h"
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void
sha1_init(struct hash_context *CTX)
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{
struct sha1_context *ctx = (void *) CTX;
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ctx->h0 = 0x67452301;
ctx->h1 = 0xefcdab89;
ctx->h2 = 0x98badcfe;
ctx->h3 = 0x10325476;
ctx->h4 = 0xc3d2e1f0;
ctx->nblocks = 0;
ctx->count = 0;
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}
/*
* Transform the message X which consists of 16 32-bit-words
*/
static void
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sha1_transform(struct sha1_context *ctx, const byte *data)
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{
u32 a,b,c,d,e,tm;
u32 x[16];
/* Get values from the chaining vars. */
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a = ctx->h0;
b = ctx->h1;
c = ctx->h2;
d = ctx->h3;
e = ctx->h4;
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#ifdef CPU_BIG_ENDIAN
memcpy(x, data, 64);
#else
int i;
for (i = 0; i < 16; i++)
x[i] = get_u32(data+4*i);
#endif
#define K1 0x5A827999L
#define K2 0x6ED9EBA1L
#define K3 0x8F1BBCDCL
#define K4 0xCA62C1D6L
#define F1(x,y,z) ( z ^ ( x & ( y ^ z ) ) )
#define F2(x,y,z) ( x ^ y ^ z )
#define F3(x,y,z) ( ( x & y ) | ( z & ( x | y ) ) )
#define F4(x,y,z) ( x ^ y ^ z )
#define M(i) (tm = x[i&0x0f] ^ x[(i-14)&0x0f] ^ x[(i-8)&0x0f] ^ x[(i-3)&0x0f], (x[i&0x0f] = ROL(tm, 1)))
/* Bitwise rotation of an unsigned int to the left **/
#define ROL(x, bits) (((x) << (bits)) | ((uint)(x) >> (sizeof(uint)*8 - (bits))))
#define R(a, b, c, d, e, f, k, m) \
do \
{ \
e += ROL(a, 5) + f(b, c, d) + k + m; \
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b = ROL(b, 30); \
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} while(0)
R( a, b, c, d, e, F1, K1, x[ 0] );
R( e, a, b, c, d, F1, K1, x[ 1] );
R( d, e, a, b, c, F1, K1, x[ 2] );
R( c, d, e, a, b, F1, K1, x[ 3] );
R( b, c, d, e, a, F1, K1, x[ 4] );
R( a, b, c, d, e, F1, K1, x[ 5] );
R( e, a, b, c, d, F1, K1, x[ 6] );
R( d, e, a, b, c, F1, K1, x[ 7] );
R( c, d, e, a, b, F1, K1, x[ 8] );
R( b, c, d, e, a, F1, K1, x[ 9] );
R( a, b, c, d, e, F1, K1, x[10] );
R( e, a, b, c, d, F1, K1, x[11] );
R( d, e, a, b, c, F1, K1, x[12] );
R( c, d, e, a, b, F1, K1, x[13] );
R( b, c, d, e, a, F1, K1, x[14] );
R( a, b, c, d, e, F1, K1, x[15] );
R( e, a, b, c, d, F1, K1, M(16) );
R( d, e, a, b, c, F1, K1, M(17) );
R( c, d, e, a, b, F1, K1, M(18) );
R( b, c, d, e, a, F1, K1, M(19) );
R( a, b, c, d, e, F2, K2, M(20) );
R( e, a, b, c, d, F2, K2, M(21) );
R( d, e, a, b, c, F2, K2, M(22) );
R( c, d, e, a, b, F2, K2, M(23) );
R( b, c, d, e, a, F2, K2, M(24) );
R( a, b, c, d, e, F2, K2, M(25) );
R( e, a, b, c, d, F2, K2, M(26) );
R( d, e, a, b, c, F2, K2, M(27) );
R( c, d, e, a, b, F2, K2, M(28) );
R( b, c, d, e, a, F2, K2, M(29) );
R( a, b, c, d, e, F2, K2, M(30) );
R( e, a, b, c, d, F2, K2, M(31) );
R( d, e, a, b, c, F2, K2, M(32) );
R( c, d, e, a, b, F2, K2, M(33) );
R( b, c, d, e, a, F2, K2, M(34) );
R( a, b, c, d, e, F2, K2, M(35) );
R( e, a, b, c, d, F2, K2, M(36) );
R( d, e, a, b, c, F2, K2, M(37) );
R( c, d, e, a, b, F2, K2, M(38) );
R( b, c, d, e, a, F2, K2, M(39) );
R( a, b, c, d, e, F3, K3, M(40) );
R( e, a, b, c, d, F3, K3, M(41) );
R( d, e, a, b, c, F3, K3, M(42) );
R( c, d, e, a, b, F3, K3, M(43) );
R( b, c, d, e, a, F3, K3, M(44) );
R( a, b, c, d, e, F3, K3, M(45) );
R( e, a, b, c, d, F3, K3, M(46) );
R( d, e, a, b, c, F3, K3, M(47) );
R( c, d, e, a, b, F3, K3, M(48) );
R( b, c, d, e, a, F3, K3, M(49) );
R( a, b, c, d, e, F3, K3, M(50) );
R( e, a, b, c, d, F3, K3, M(51) );
R( d, e, a, b, c, F3, K3, M(52) );
R( c, d, e, a, b, F3, K3, M(53) );
R( b, c, d, e, a, F3, K3, M(54) );
R( a, b, c, d, e, F3, K3, M(55) );
R( e, a, b, c, d, F3, K3, M(56) );
R( d, e, a, b, c, F3, K3, M(57) );
R( c, d, e, a, b, F3, K3, M(58) );
R( b, c, d, e, a, F3, K3, M(59) );
R( a, b, c, d, e, F4, K4, M(60) );
R( e, a, b, c, d, F4, K4, M(61) );
R( d, e, a, b, c, F4, K4, M(62) );
R( c, d, e, a, b, F4, K4, M(63) );
R( b, c, d, e, a, F4, K4, M(64) );
R( a, b, c, d, e, F4, K4, M(65) );
R( e, a, b, c, d, F4, K4, M(66) );
R( d, e, a, b, c, F4, K4, M(67) );
R( c, d, e, a, b, F4, K4, M(68) );
R( b, c, d, e, a, F4, K4, M(69) );
R( a, b, c, d, e, F4, K4, M(70) );
R( e, a, b, c, d, F4, K4, M(71) );
R( d, e, a, b, c, F4, K4, M(72) );
R( c, d, e, a, b, F4, K4, M(73) );
R( b, c, d, e, a, F4, K4, M(74) );
R( a, b, c, d, e, F4, K4, M(75) );
R( e, a, b, c, d, F4, K4, M(76) );
R( d, e, a, b, c, F4, K4, M(77) );
R( c, d, e, a, b, F4, K4, M(78) );
R( b, c, d, e, a, F4, K4, M(79) );
/* Update chaining vars. */
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ctx->h0 += a;
ctx->h1 += b;
ctx->h2 += c;
ctx->h3 += d;
ctx->h4 += e;
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}
/*
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* Update the message digest with the contents of BUF with length LEN.
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*/
void
sha1_update(struct hash_context *CTX, const byte *buf, uint len)
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{
struct sha1_context *ctx = (void *) CTX;
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if (ctx->count)
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{
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/* Fill rest of internal buffer */
for (; len && ctx->count < SHA1_BLOCK_SIZE; len--)
ctx->buf[ctx->count++] = *buf++;
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if (ctx->count < SHA1_BLOCK_SIZE)
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return;
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/* Process data from internal buffer */
sha1_transform(ctx, ctx->buf);
ctx->nblocks++;
ctx->count = 0;
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}
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if (!len)
return;
/* Process data from input buffer */
while (len >= SHA1_BLOCK_SIZE)
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{
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sha1_transform(ctx, buf);
ctx->nblocks++;
buf += SHA1_BLOCK_SIZE;
len -= SHA1_BLOCK_SIZE;
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}
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/* Copy remaining data to internal buffer */
memcpy(ctx->buf, buf, len);
ctx->count = len;
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}
/*
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* 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.
*
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* Returns: 20 bytes representing the digest.
*/
byte *
sha1_final(struct hash_context *CTX)
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{
struct sha1_context *ctx = (void *) CTX;
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u32 t, msb, lsb;
sha1_update(CTX, NULL, 0); /* flush */
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t = ctx->nblocks;
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/* multiply by 64 to make a byte count */
lsb = t << 6;
msb = t >> 26;
/* add the count */
t = lsb;
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if ((lsb += ctx->count) < t)
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msb++;
/* multiply by 8 to make a bit count */
t = lsb;
lsb <<= 3;
msb <<= 3;
msb |= t >> 29;
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if (ctx->count < 56)
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{
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/* enough room */
ctx->buf[ctx->count++] = 0x80; /* pad */
while (ctx->count < 56)
ctx->buf[ctx->count++] = 0; /* pad */
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}
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else
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{
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/* need one extra block */
ctx->buf[ctx->count++] = 0x80; /* pad character */
while (ctx->count < 64)
ctx->buf[ctx->count++] = 0;
sha1_update(CTX, NULL, 0); /* flush */
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memset(ctx->buf, 0, 56); /* fill next block with zeroes */
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}
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/* append the 64 bit count */
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ctx->buf[56] = msb >> 24;
ctx->buf[57] = msb >> 16;
ctx->buf[58] = msb >> 8;
ctx->buf[59] = msb;
ctx->buf[60] = lsb >> 24;
ctx->buf[61] = lsb >> 16;
ctx->buf[62] = lsb >> 8;
ctx->buf[63] = lsb;
sha1_transform(ctx, ctx->buf);
byte *p = ctx->buf;
#define X(a) do { put_u32(p, ctx->h##a); p += 4; } while(0)
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X(0);
X(1);
X(2);
X(3);
X(4);
#undef X
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return ctx->buf;
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}