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Diffstat (limited to 'module/zfs/sha256.c')
| -rw-r--r-- | module/zfs/sha256.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/module/zfs/sha256.c b/module/zfs/sha256.c new file mode 100644 index 000000000..ca7076cb6 --- /dev/null +++ b/module/zfs/sha256.c @@ -0,0 +1,129 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright 2007 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#pragma ident "%Z%%M% %I% %E% SMI" + +#include <sys/zfs_context.h> +#include <sys/zio.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) +{ + 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]); +} |