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authorMatt Johnston <matt@ucc.asn.au>2007-01-11 02:41:05 +0000
committerMatt Johnston <matt@ucc.asn.au>2007-01-11 02:41:05 +0000
commita938f4cfe140e8561d9dbf108b896492a662a893 (patch)
treef2a74322f959ff6a505ba5e87274ebe3d17d5e74 /libtomcrypt/src/encauth/gcm/gcm_gf_mult.c
parent692d737a821c5e401c227d936b8f0d76b955650f (diff)
parent28ad393b008b34bc3cdbaa192440b8cc615329f0 (diff)
propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f)
to branch 'au.asn.ucc.matt.dropbear' (head 02c413252c90e9de8e03d91e9939dde3029f5c0a) --HG-- extra : convert_revision : 52ccb0ad0587a62bc64aecb939adbb76546aac16
Diffstat (limited to 'libtomcrypt/src/encauth/gcm/gcm_gf_mult.c')
-rw-r--r--libtomcrypt/src/encauth/gcm/gcm_gf_mult.c179
1 files changed, 153 insertions, 26 deletions
diff --git a/libtomcrypt/src/encauth/gcm/gcm_gf_mult.c b/libtomcrypt/src/encauth/gcm/gcm_gf_mult.c
index 06db22b..52e82dd 100644
--- a/libtomcrypt/src/encauth/gcm/gcm_gf_mult.c
+++ b/libtomcrypt/src/encauth/gcm/gcm_gf_mult.c
@@ -6,17 +6,59 @@
* The library is free for all purposes without any express
* guarantee it works.
*
- * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
*/
/**
@file gcm_gf_mult.c
- GCM implementation, initialize state, by Tom St Denis
+ GCM implementation, do the GF mult, by Tom St Denis
*/
#include "tomcrypt.h"
-#ifdef GCM_MODE
+#if defined(GCM_TABLES) || defined(LRW_TABLES) || ((defined(GCM_MODE) || defined(GCM_MODE)) && defined(LTC_FAST))
+/* this is x*2^128 mod p(x) ... the results are 16 bytes each stored in a packed format. Since only the
+ * lower 16 bits are not zero'ed I removed the upper 14 bytes */
+const unsigned char gcm_shift_table[256*2] = {
+0x00, 0x00, 0x01, 0xc2, 0x03, 0x84, 0x02, 0x46, 0x07, 0x08, 0x06, 0xca, 0x04, 0x8c, 0x05, 0x4e,
+0x0e, 0x10, 0x0f, 0xd2, 0x0d, 0x94, 0x0c, 0x56, 0x09, 0x18, 0x08, 0xda, 0x0a, 0x9c, 0x0b, 0x5e,
+0x1c, 0x20, 0x1d, 0xe2, 0x1f, 0xa4, 0x1e, 0x66, 0x1b, 0x28, 0x1a, 0xea, 0x18, 0xac, 0x19, 0x6e,
+0x12, 0x30, 0x13, 0xf2, 0x11, 0xb4, 0x10, 0x76, 0x15, 0x38, 0x14, 0xfa, 0x16, 0xbc, 0x17, 0x7e,
+0x38, 0x40, 0x39, 0x82, 0x3b, 0xc4, 0x3a, 0x06, 0x3f, 0x48, 0x3e, 0x8a, 0x3c, 0xcc, 0x3d, 0x0e,
+0x36, 0x50, 0x37, 0x92, 0x35, 0xd4, 0x34, 0x16, 0x31, 0x58, 0x30, 0x9a, 0x32, 0xdc, 0x33, 0x1e,
+0x24, 0x60, 0x25, 0xa2, 0x27, 0xe4, 0x26, 0x26, 0x23, 0x68, 0x22, 0xaa, 0x20, 0xec, 0x21, 0x2e,
+0x2a, 0x70, 0x2b, 0xb2, 0x29, 0xf4, 0x28, 0x36, 0x2d, 0x78, 0x2c, 0xba, 0x2e, 0xfc, 0x2f, 0x3e,
+0x70, 0x80, 0x71, 0x42, 0x73, 0x04, 0x72, 0xc6, 0x77, 0x88, 0x76, 0x4a, 0x74, 0x0c, 0x75, 0xce,
+0x7e, 0x90, 0x7f, 0x52, 0x7d, 0x14, 0x7c, 0xd6, 0x79, 0x98, 0x78, 0x5a, 0x7a, 0x1c, 0x7b, 0xde,
+0x6c, 0xa0, 0x6d, 0x62, 0x6f, 0x24, 0x6e, 0xe6, 0x6b, 0xa8, 0x6a, 0x6a, 0x68, 0x2c, 0x69, 0xee,
+0x62, 0xb0, 0x63, 0x72, 0x61, 0x34, 0x60, 0xf6, 0x65, 0xb8, 0x64, 0x7a, 0x66, 0x3c, 0x67, 0xfe,
+0x48, 0xc0, 0x49, 0x02, 0x4b, 0x44, 0x4a, 0x86, 0x4f, 0xc8, 0x4e, 0x0a, 0x4c, 0x4c, 0x4d, 0x8e,
+0x46, 0xd0, 0x47, 0x12, 0x45, 0x54, 0x44, 0x96, 0x41, 0xd8, 0x40, 0x1a, 0x42, 0x5c, 0x43, 0x9e,
+0x54, 0xe0, 0x55, 0x22, 0x57, 0x64, 0x56, 0xa6, 0x53, 0xe8, 0x52, 0x2a, 0x50, 0x6c, 0x51, 0xae,
+0x5a, 0xf0, 0x5b, 0x32, 0x59, 0x74, 0x58, 0xb6, 0x5d, 0xf8, 0x5c, 0x3a, 0x5e, 0x7c, 0x5f, 0xbe,
+0xe1, 0x00, 0xe0, 0xc2, 0xe2, 0x84, 0xe3, 0x46, 0xe6, 0x08, 0xe7, 0xca, 0xe5, 0x8c, 0xe4, 0x4e,
+0xef, 0x10, 0xee, 0xd2, 0xec, 0x94, 0xed, 0x56, 0xe8, 0x18, 0xe9, 0xda, 0xeb, 0x9c, 0xea, 0x5e,
+0xfd, 0x20, 0xfc, 0xe2, 0xfe, 0xa4, 0xff, 0x66, 0xfa, 0x28, 0xfb, 0xea, 0xf9, 0xac, 0xf8, 0x6e,
+0xf3, 0x30, 0xf2, 0xf2, 0xf0, 0xb4, 0xf1, 0x76, 0xf4, 0x38, 0xf5, 0xfa, 0xf7, 0xbc, 0xf6, 0x7e,
+0xd9, 0x40, 0xd8, 0x82, 0xda, 0xc4, 0xdb, 0x06, 0xde, 0x48, 0xdf, 0x8a, 0xdd, 0xcc, 0xdc, 0x0e,
+0xd7, 0x50, 0xd6, 0x92, 0xd4, 0xd4, 0xd5, 0x16, 0xd0, 0x58, 0xd1, 0x9a, 0xd3, 0xdc, 0xd2, 0x1e,
+0xc5, 0x60, 0xc4, 0xa2, 0xc6, 0xe4, 0xc7, 0x26, 0xc2, 0x68, 0xc3, 0xaa, 0xc1, 0xec, 0xc0, 0x2e,
+0xcb, 0x70, 0xca, 0xb2, 0xc8, 0xf4, 0xc9, 0x36, 0xcc, 0x78, 0xcd, 0xba, 0xcf, 0xfc, 0xce, 0x3e,
+0x91, 0x80, 0x90, 0x42, 0x92, 0x04, 0x93, 0xc6, 0x96, 0x88, 0x97, 0x4a, 0x95, 0x0c, 0x94, 0xce,
+0x9f, 0x90, 0x9e, 0x52, 0x9c, 0x14, 0x9d, 0xd6, 0x98, 0x98, 0x99, 0x5a, 0x9b, 0x1c, 0x9a, 0xde,
+0x8d, 0xa0, 0x8c, 0x62, 0x8e, 0x24, 0x8f, 0xe6, 0x8a, 0xa8, 0x8b, 0x6a, 0x89, 0x2c, 0x88, 0xee,
+0x83, 0xb0, 0x82, 0x72, 0x80, 0x34, 0x81, 0xf6, 0x84, 0xb8, 0x85, 0x7a, 0x87, 0x3c, 0x86, 0xfe,
+0xa9, 0xc0, 0xa8, 0x02, 0xaa, 0x44, 0xab, 0x86, 0xae, 0xc8, 0xaf, 0x0a, 0xad, 0x4c, 0xac, 0x8e,
+0xa7, 0xd0, 0xa6, 0x12, 0xa4, 0x54, 0xa5, 0x96, 0xa0, 0xd8, 0xa1, 0x1a, 0xa3, 0x5c, 0xa2, 0x9e,
+0xb5, 0xe0, 0xb4, 0x22, 0xb6, 0x64, 0xb7, 0xa6, 0xb2, 0xe8, 0xb3, 0x2a, 0xb1, 0x6c, 0xb0, 0xae,
+0xbb, 0xf0, 0xba, 0x32, 0xb8, 0x74, 0xb9, 0xb6, 0xbc, 0xf8, 0xbd, 0x3a, 0xbf, 0x7c, 0xbe, 0xbe };
+
+#endif
+
+
+#if defined(GCM_MODE) || defined(LRW_MODE)
+
+#ifndef LTC_FAST
/* right shift */
static void gcm_rightshift(unsigned char *a)
{
@@ -33,7 +75,7 @@ static const unsigned char poly[] = { 0x00, 0xE1 };
/**
- GCM GF multiplier (internal use only)
+ GCM GF multiplier (internal use only) bitserial
@param a First value
@param b Second value
@param c Destination for a * b
@@ -58,37 +100,122 @@ void gcm_gf_mult(const unsigned char *a, const unsigned char *b, unsigned char *
XMEMCPY(c, Z, 16);
}
+#else
+
+/* map normal numbers to "ieee" way ... e.g. bit reversed */
+#define M(x) ( ((x&8)>>3) | ((x&4)>>1) | ((x&2)<<1) | ((x&1)<<3) )
+
+#define BPD (sizeof(LTC_FAST_TYPE) * 8)
+#define WPV (1 + (16 / sizeof(LTC_FAST_TYPE)))
+
/**
- GCM multiply by H
- @param gcm The GCM state which holds the H value
- @param I The value to multiply H by
- */
-void gcm_mult_h(gcm_state *gcm, unsigned char *I)
+ GCM GF multiplier (internal use only) word oriented
+ @param a First value
+ @param b Second value
+ @param c Destination for a * b
+ */
+void gcm_gf_mult(const unsigned char *a, const unsigned char *b, unsigned char *c)
{
- unsigned char T[16];
-#ifdef GCM_TABLES
- int x, y;
- XMEMCPY(T, &gcm->PC[0][I[0]][0], 16);
- for (x = 1; x < 16; x++) {
-#ifdef LTC_FAST
- for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
- *((LTC_FAST_TYPE *)(T + y)) ^= *((LTC_FAST_TYPE *)(&gcm->PC[x][I[x]][y]));
+ int i, j, k, u;
+ LTC_FAST_TYPE B[16][WPV], tmp[32 / sizeof(LTC_FAST_TYPE)], pB[16 / sizeof(LTC_FAST_TYPE)], zz, z;
+ unsigned char pTmp[32];
+
+ /* create simple tables */
+ zeromem(B[0], sizeof(B[0]));
+ zeromem(B[M(1)], sizeof(B[M(1)]));
+
+#ifdef ENDIAN_32BITWORD
+ for (i = 0; i < 4; i++) {
+ LOAD32H(B[M(1)][i], a + (i<<2));
+ LOAD32L(pB[i], b + (i<<2));
+ }
+#else
+ for (i = 0; i < 2; i++) {
+ LOAD64H(B[M(1)][i], a + (i<<3));
+ LOAD64L(pB[i], b + (i<<3));
+ }
+#endif
+
+ /* now create 2, 4 and 8 */
+ B[M(2)][0] = B[M(1)][0] >> 1;
+ B[M(4)][0] = B[M(1)][0] >> 2;
+ B[M(8)][0] = B[M(1)][0] >> 3;
+ for (i = 1; i < (int)WPV; i++) {
+ B[M(2)][i] = (B[M(1)][i-1] << (BPD-1)) | (B[M(1)][i] >> 1);
+ B[M(4)][i] = (B[M(1)][i-1] << (BPD-2)) | (B[M(1)][i] >> 2);
+ B[M(8)][i] = (B[M(1)][i-1] << (BPD-3)) | (B[M(1)][i] >> 3);
+ }
+
+ /* now all values with two bits which are 3, 5, 6, 9, 10, 12 */
+ for (i = 0; i < (int)WPV; i++) {
+ B[M(3)][i] = B[M(1)][i] ^ B[M(2)][i];
+ B[M(5)][i] = B[M(1)][i] ^ B[M(4)][i];
+ B[M(6)][i] = B[M(2)][i] ^ B[M(4)][i];
+ B[M(9)][i] = B[M(1)][i] ^ B[M(8)][i];
+ B[M(10)][i] = B[M(2)][i] ^ B[M(8)][i];
+ B[M(12)][i] = B[M(8)][i] ^ B[M(4)][i];
+
+ /* now all 3 bit values and the only 4 bit value: 7, 11, 13, 14, 15 */
+ B[M(7)][i] = B[M(3)][i] ^ B[M(4)][i];
+ B[M(11)][i] = B[M(3)][i] ^ B[M(8)][i];
+ B[M(13)][i] = B[M(1)][i] ^ B[M(12)][i];
+ B[M(14)][i] = B[M(6)][i] ^ B[M(8)][i];
+ B[M(15)][i] = B[M(7)][i] ^ B[M(8)][i];
+ }
+
+ zeromem(tmp, sizeof(tmp));
+
+ /* compute product four bits of each word at a time */
+ /* for each nibble */
+ for (i = (BPD/4)-1; i >= 0; i--) {
+ /* for each word */
+ for (j = 0; j < (int)(WPV-1); j++) {
+ /* grab the 4 bits recall the nibbles are backwards so it's a shift by (i^1)*4 */
+ u = (pB[j] >> ((i^1)<<2)) & 15;
+
+ /* add offset by the word count the table looked up value to the result */
+ for (k = 0; k < (int)WPV; k++) {
+ tmp[k+j] ^= B[u][k];
+ }
}
-#else
- for (y = 0; y < 16; y++) {
- T[y] ^= gcm->PC[x][I[x]][y];
+ /* shift result up by 4 bits */
+ if (i != 0) {
+ for (z = j = 0; j < (int)(32 / sizeof(LTC_FAST_TYPE)); j++) {
+ zz = tmp[j] << (BPD-4);
+ tmp[j] = (tmp[j] >> 4) | z;
+ z = zz;
+ }
}
-#endif
}
-#else
- gcm_gf_mult(gcm->H, I, T);
+
+ /* store product */
+#ifdef ENDIAN_32BITWORD
+ for (i = 0; i < 8; i++) {
+ STORE32H(tmp[i], pTmp + (i<<2));
+ }
+#else
+ for (i = 0; i < 4; i++) {
+ STORE64H(tmp[i], pTmp + (i<<3));
+ }
#endif
- XMEMCPY(I, T, 16);
+
+ /* reduce by taking most significant byte and adding the appropriate two byte sequence 16 bytes down */
+ for (i = 31; i >= 16; i--) {
+ pTmp[i-16] ^= gcm_shift_table[((unsigned)pTmp[i]<<1)];
+ pTmp[i-15] ^= gcm_shift_table[((unsigned)pTmp[i]<<1)+1];
+ }
+
+ for (i = 0; i < 16; i++) {
+ c[i] = pTmp[i];
+ }
+
}
+#endif
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/encauth/gcm/gcm_gf_mult.c,v $ */
-/* $Revision: 1.16 $ */
-/* $Date: 2005/05/21 14:33:42 $ */
+/* $Revision: 1.23 $ */
+/* $Date: 2006/03/31 14:15:35 $ */
+