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authorBrian Behlendorf <[email protected]>2010-08-26 11:52:05 -0700
committerBrian Behlendorf <[email protected]>2010-08-31 13:41:59 -0700
commit9c905c550bb9cb095a5d9707bc7cf72d3f2562af (patch)
tree30671b0210e40f961b0cc3e1ced1bc7908bbfba8 /module/zfs
parenta26baf285f71eb95f1eace8c79d12d647a694488 (diff)
Add linux sha2 support
The upstream ZFS code has correctly moved to a faster native sha2 implementation. Unfortunately, under Linux that's going to be a little problematic so we revert the code to the more portable version contained in earlier ZFS releases. Using the native sha2 implementation in Linux is possible but the API is slightly different in kernel version user space depending on which libraries are used. Ideally, we need a fast implementation of SHA256 which builds as part of ZFS this shouldn't be that hard to do but it will take some effort. Signed-off-by: Brian Behlendorf <[email protected]>
Diffstat (limited to 'module/zfs')
-rw-r--r--module/zfs/sha256.c117
1 files changed, 97 insertions, 20 deletions
diff --git a/module/zfs/sha256.c b/module/zfs/sha256.c
index f515be6bb..cf9dd8fcb 100644
--- a/module/zfs/sha256.c
+++ b/module/zfs/sha256.c
@@ -19,32 +19,109 @@
* CDDL HEADER END
*/
/*
- * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
+ * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
+
#include <sys/zfs_context.h>
#include <sys/zio.h>
-#include <sys/sha2.h>
+#include <sys/zio_checksum.h>
+
+/*
+ * SHA-256 checksum, as specified in FIPS 180-3, available at:
+ * http://csrc.nist.gov/publications/PubsFIPS.html
+ *
+ * This is a very compact implementation of SHA-256.
+ * It is designed to be simple and portable, not to be fast.
+ */
+
+/*
+ * The literal definitions of Ch() and Maj() according to FIPS 180-3 are:
+ *
+ * Ch(x, y, z) (x & y) ^ (~x & z)
+ * Maj(x, y, z) (x & y) ^ (x & z) ^ (y & z)
+ *
+ * We use equivalent logical reductions here that require one less op.
+ */
+#define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
+#define Maj(x, y, z) (((x) & (y)) ^ ((z) & ((x) ^ (y))))
+#define Rot32(x, s) (((x) >> s) | ((x) << (32 - s)))
+#define SIGMA0(x) (Rot32(x, 2) ^ Rot32(x, 13) ^ Rot32(x, 22))
+#define SIGMA1(x) (Rot32(x, 6) ^ Rot32(x, 11) ^ Rot32(x, 25))
+#define sigma0(x) (Rot32(x, 7) ^ Rot32(x, 18) ^ ((x) >> 3))
+#define sigma1(x) (Rot32(x, 17) ^ Rot32(x, 19) ^ ((x) >> 10))
+
+static const uint32_t SHA256_K[64] = {
+ 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+ 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+ 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+ 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+ 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+ 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+ 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+ 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+ 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+ 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+ 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+ 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+ 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+ 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+ 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+ 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+};
+
+static void
+SHA256Transform(uint32_t *H, const uint8_t *cp)
+{
+ uint32_t a, b, c, d, e, f, g, h, t, T1, T2, W[64];
+
+ for (t = 0; t < 16; t++, cp += 4)
+ W[t] = (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3];
+
+ for (t = 16; t < 64; t++)
+ W[t] = sigma1(W[t - 2]) + W[t - 7] +
+ sigma0(W[t - 15]) + W[t - 16];
+
+ a = H[0]; b = H[1]; c = H[2]; d = H[3];
+ e = H[4]; f = H[5]; g = H[6]; h = H[7];
+
+ for (t = 0; t < 64; t++) {
+ T1 = h + SIGMA1(e) + Ch(e, f, g) + SHA256_K[t] + W[t];
+ T2 = SIGMA0(a) + Maj(a, b, c);
+ h = g; g = f; f = e; e = d + T1;
+ d = c; c = b; b = a; a = T1 + T2;
+ }
+
+ H[0] += a; H[1] += b; H[2] += c; H[3] += d;
+ H[4] += e; H[5] += f; H[6] += g; H[7] += h;
+}
void
zio_checksum_SHA256(const void *buf, uint64_t size, zio_cksum_t *zcp)
{
- SHA2_CTX ctx;
- zio_cksum_t tmp;
-
- SHA2Init(SHA256, &ctx);
- SHA2Update(&ctx, buf, size);
- SHA2Final(&tmp, &ctx);
-
- /*
- * A prior implementation of this function had a
- * private SHA256 implementation always wrote things out in
- * Big Endian and there wasn't a byteswap variant of it.
- * To preseve on disk compatibility we need to force that
- * behaviour.
- */
- zcp->zc_word[0] = BE_64(tmp.zc_word[0]);
- zcp->zc_word[1] = BE_64(tmp.zc_word[1]);
- zcp->zc_word[2] = BE_64(tmp.zc_word[2]);
- zcp->zc_word[3] = BE_64(tmp.zc_word[3]);
+ uint32_t H[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+ 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };
+ uint8_t pad[128];
+ int i, padsize;
+
+ for (i = 0; i < (size & ~63ULL); i += 64)
+ SHA256Transform(H, (uint8_t *)buf + i);
+
+ for (padsize = 0; i < size; i++)
+ pad[padsize++] = *((uint8_t *)buf + i);
+
+ for (pad[padsize++] = 0x80; (padsize & 63) != 56; padsize++)
+ pad[padsize] = 0;
+
+ for (i = 56; i >= 0; i -= 8)
+ pad[padsize++] = (size << 3) >> i;
+
+ for (i = 0; i < padsize; i += 64)
+ SHA256Transform(H, pad + i);
+
+ ZIO_SET_CHECKSUM(zcp,
+ (uint64_t)H[0] << 32 | H[1],
+ (uint64_t)H[2] << 32 | H[3],
+ (uint64_t)H[4] << 32 | H[5],
+ (uint64_t)H[6] << 32 | H[7]);
}