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Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
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* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: sha512 - reduce stack usage to safe number
  crypto: sha512 - make it work, undo percpu message schedule
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torvalds committed Jan 26, 2012
2 parents aaad641 + 51fc6dc commit 87f71ae
Showing 1 changed file with 34 additions and 28 deletions.
62 changes: 34 additions & 28 deletions crypto/sha512_generic.c
Original file line number Diff line number Diff line change
Expand Up @@ -21,8 +21,6 @@
#include <linux/percpu.h>
#include <asm/byteorder.h>

static DEFINE_PER_CPU(u64[80], msg_schedule);

static inline u64 Ch(u64 x, u64 y, u64 z)
{
return z ^ (x & (y ^ z));
Expand Down Expand Up @@ -80,7 +78,7 @@ static inline void LOAD_OP(int I, u64 *W, const u8 *input)

static inline void BLEND_OP(int I, u64 *W)
{
W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
W[I % 16] += s1(W[(I-2) % 16]) + W[(I-7) % 16] + s0(W[(I-15) % 16]);
}

static void
Expand All @@ -89,47 +87,55 @@ sha512_transform(u64 *state, const u8 *input)
u64 a, b, c, d, e, f, g, h, t1, t2;

int i;
u64 *W = get_cpu_var(msg_schedule);
u64 W[16];

/* load the input */
for (i = 0; i < 16; i++)
LOAD_OP(i, W, input);

for (i = 16; i < 80; i++) {
BLEND_OP(i, W);
}

/* load the state into our registers */
a=state[0]; b=state[1]; c=state[2]; d=state[3];
e=state[4]; f=state[5]; g=state[6]; h=state[7];

/* now iterate */
for (i=0; i<80; i+=8) {
t1 = h + e1(e) + Ch(e,f,g) + sha512_K[i ] + W[i ];
t2 = e0(a) + Maj(a,b,c); d+=t1; h=t1+t2;
t1 = g + e1(d) + Ch(d,e,f) + sha512_K[i+1] + W[i+1];
t2 = e0(h) + Maj(h,a,b); c+=t1; g=t1+t2;
t1 = f + e1(c) + Ch(c,d,e) + sha512_K[i+2] + W[i+2];
t2 = e0(g) + Maj(g,h,a); b+=t1; f=t1+t2;
t1 = e + e1(b) + Ch(b,c,d) + sha512_K[i+3] + W[i+3];
t2 = e0(f) + Maj(f,g,h); a+=t1; e=t1+t2;
t1 = d + e1(a) + Ch(a,b,c) + sha512_K[i+4] + W[i+4];
t2 = e0(e) + Maj(e,f,g); h+=t1; d=t1+t2;
t1 = c + e1(h) + Ch(h,a,b) + sha512_K[i+5] + W[i+5];
t2 = e0(d) + Maj(d,e,f); g+=t1; c=t1+t2;
t1 = b + e1(g) + Ch(g,h,a) + sha512_K[i+6] + W[i+6];
t2 = e0(c) + Maj(c,d,e); f+=t1; b=t1+t2;
t1 = a + e1(f) + Ch(f,g,h) + sha512_K[i+7] + W[i+7];
t2 = e0(b) + Maj(b,c,d); e+=t1; a=t1+t2;
#define SHA512_0_15(i, a, b, c, d, e, f, g, h) \
t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[i]; \
t2 = e0(a) + Maj(a, b, c); \
d += t1; \
h = t1 + t2

#define SHA512_16_79(i, a, b, c, d, e, f, g, h) \
BLEND_OP(i, W); \
t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[(i)%16]; \
t2 = e0(a) + Maj(a, b, c); \
d += t1; \
h = t1 + t2

for (i = 0; i < 16; i += 8) {
SHA512_0_15(i, a, b, c, d, e, f, g, h);
SHA512_0_15(i + 1, h, a, b, c, d, e, f, g);
SHA512_0_15(i + 2, g, h, a, b, c, d, e, f);
SHA512_0_15(i + 3, f, g, h, a, b, c, d, e);
SHA512_0_15(i + 4, e, f, g, h, a, b, c, d);
SHA512_0_15(i + 5, d, e, f, g, h, a, b, c);
SHA512_0_15(i + 6, c, d, e, f, g, h, a, b);
SHA512_0_15(i + 7, b, c, d, e, f, g, h, a);
}
for (i = 16; i < 80; i += 8) {
SHA512_16_79(i, a, b, c, d, e, f, g, h);
SHA512_16_79(i + 1, h, a, b, c, d, e, f, g);
SHA512_16_79(i + 2, g, h, a, b, c, d, e, f);
SHA512_16_79(i + 3, f, g, h, a, b, c, d, e);
SHA512_16_79(i + 4, e, f, g, h, a, b, c, d);
SHA512_16_79(i + 5, d, e, f, g, h, a, b, c);
SHA512_16_79(i + 6, c, d, e, f, g, h, a, b);
SHA512_16_79(i + 7, b, c, d, e, f, g, h, a);
}

state[0] += a; state[1] += b; state[2] += c; state[3] += d;
state[4] += e; state[5] += f; state[6] += g; state[7] += h;

/* erase our data */
a = b = c = d = e = f = g = h = t1 = t2 = 0;
memset(W, 0, sizeof(__get_cpu_var(msg_schedule)));
put_cpu_var(msg_schedule);
}

static int
Expand Down

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