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authorRob Landley <rob@landley.net>2007-11-24 22:05:29 -0600
committerRob Landley <rob@landley.net>2007-11-24 22:05:29 -0600
commit57389ec1d8f5b32e5de97f0f557e5f5c5b7054bb (patch)
tree1775a2b365fd19cd2acabce2d46220d38400f362 /toys/sha1.c
parentf1980822a807409f7332e4c8f4c0fb60d467d676 (diff)
downloadtoybox-57389ec1d8f5b32e5de97f0f557e5f5c5b7054bb.tar.gz
Re-roll loop, making code smaller. Also localize all the crypto information
into a struct that can be blanked in finalize (no more zeroing local variables).
Diffstat (limited to 'toys/sha1.c')
-rw-r--r--toys/sha1.c78
1 files changed, 35 insertions, 43 deletions
diff --git a/toys/sha1.c b/toys/sha1.c
index b57805f9..77228afb 100644
--- a/toys/sha1.c
+++ b/toys/sha1.c
@@ -13,6 +13,7 @@
struct sha1 {
uint32_t state[5];
+ uint32_t oldstate[5];
uint64_t count;
union {
unsigned char c[64];
@@ -38,12 +39,7 @@ void sha1_final(struct sha1 *this, unsigned char digest[20]);
#define blk(i) (block[i&15] = rol(block[(i+13)&15]^block[(i+8)&15] \
^block[(i+2)&15]^block[i&15],1))
-/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
-#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
-#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
-#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
-#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
-#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
+static const uint32_t rconsts[]={0x5A827999,0x6ED9EBA1,0x8F1BBCDC,0xCA62C1D6};
void printy(unsigned char *this)
{
@@ -57,45 +53,41 @@ void printy(unsigned char *this)
void sha1_transform(struct sha1 *this)
{
- unsigned int a, b, c, d, e;
+ int i, j, k, count;
uint32_t *block = this->buffer.i;
+ uint32_t *rot[5], *temp;
/* Copy context->state[] to working vars */
- a = this->state[0];
- b = this->state[1];
- c = this->state[2];
- d = this->state[3];
- e = this->state[4];
- /* 4 rounds of 20 operations each. Loop unrolled. */
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- 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);
- /* Add the working vars back into context.state[] */
- this->state[0] += a;
- this->state[1] += b;
- this->state[2] += c;
- this->state[3] += d;
- this->state[4] += e;
-printy(this->state);
- /* Wipe variables */
- a = b = c = d = e = 0;
+ for (i=0; i<5; i++) {
+ this->oldstate[i] = this->state[i];
+ rot[i] = this->state + i;
+ }
+ /* 4 rounds of 20 operations each. */
+ for (i=count=0; i<4; i++) {
+ for (j=0; j<20; j++) {
+ uint32_t work;
+
+ work = *rot[2] ^ *rot[3];
+ if (!i) work = (work & *rot[1]) ^ *rot[3];
+ else {
+ if (i==2)
+ work = ((*rot[1]|*rot[2])&*rot[3])|(*rot[1]&*rot[2]);
+ else work ^= *rot[1];
+ }
+ if (!i && j<16) work += blk0(count);
+ else work += blk(count);
+ *rot[4] += work + rol(*rot[0],5) + rconsts[i];
+ *rot[1] = rol(*rot[1],30);
+
+ // Rotate by one for next time.
+ temp = rot[4];
+ for (k=4; k; k--) rot[k] = rot[k-1];
+ *rot = temp;
+ count++;
+ }
+ }
+ /* Add the previous values of state[] */
+ for (i=0; i<5; i++) this->state[i] += this->oldstate[i];
}
@@ -163,7 +155,7 @@ void sha1_final(struct sha1 *this, unsigned char digest[20])
((this->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
}
/* Wipe variables */
- i = 0;
+ memset(this, 0, sizeof(struct sha1));
}