| /***************************************************************************** |
| * Copyright (c) 2015-2020 IBM Corporation |
| * All rights reserved. |
| * This program and the accompanying materials |
| * are made available under the terms of the BSD License |
| * which accompanies this distribution, and is available at |
| * http://www.opensource.org/licenses/bsd-license.php |
| * |
| * Contributors: |
| * IBM Corporation - initial implementation |
| *****************************************************************************/ |
| |
| /* |
| * See: NIST standard for SHA-256 in FIPS PUB 180-4 |
| */ |
| |
| #include "config.h" |
| #include "byteorder.h" |
| #include "sha.h" |
| #include "string.h" |
| #include "x86.h" |
| |
| typedef struct _sha256_ctx { |
| u32 h[8]; |
| } sha256_ctx; |
| |
| static inline u32 Ch(u32 x, u32 y, u32 z) |
| { |
| return (x & y) | ((x ^ 0xffffffff) & z); |
| } |
| |
| static inline u32 Maj(u32 x, u32 y, u32 z) |
| { |
| return (x & y) | (x & z) | (y & z); |
| } |
| |
| static inline u32 sum0(u32 x) |
| { |
| return ror(x, 2) ^ ror(x, 13) ^ ror(x, 22); |
| } |
| |
| static inline u32 sum1(u32 x) |
| { |
| return ror(x, 6) ^ ror(x, 11) ^ ror(x, 25); |
| } |
| |
| static inline u32 sigma0(u32 x) |
| { |
| return ror(x, 7) ^ ror(x, 18) ^ (x >> 3); |
| } |
| |
| static inline u32 sigma1(u32 x) |
| { |
| return ror(x, 17) ^ ror(x, 19) ^ (x >> 10); |
| } |
| |
| static void sha256_block(u32 *w, sha256_ctx *ctx) |
| { |
| u32 t; |
| u32 a, b, c, d, e, f, g, h; |
| u32 T1, T2; |
| |
| /* |
| * FIPS 180-4 4.2.2: SHA256 Constants |
| */ |
| static const u32 sha_ko[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 |
| }; |
| |
| /* |
| * FIPS 180-4 6.2.2: step 1 |
| * |
| * 0 <= i <= 15: |
| * W(t) = M(t) |
| * 16 <= i <= 63: |
| * W(t) = sigma1(W(t-2)) + W(t-7) + sigma0(W(t-15)) + W(t-16) |
| */ |
| |
| /* w(0)..w(15) are in big endian format */ |
| for (t = 0; t <= 15; t++) |
| w[t] = be32_to_cpu(w[t]); |
| |
| for (t = 16; t <= 63; t++) |
| w[t] = sigma1(w[t-2]) + w[t-7] + sigma0(w[t-15]) + w[t-16]; |
| |
| /* |
| * step 2: a = H0, b = H1, c = H2, d = H3, e = H4, f = H5, g = H6, h = H7 |
| */ |
| a = ctx->h[0]; |
| b = ctx->h[1]; |
| c = ctx->h[2]; |
| d = ctx->h[3]; |
| e = ctx->h[4]; |
| f = ctx->h[5]; |
| g = ctx->h[6]; |
| h = ctx->h[7]; |
| |
| /* |
| * step 3: For i = 0 to 63: |
| * T1 = h + sum1(e) + Ch(e,f,g) + K(t) + W(t); |
| * T2 = sum0(a) + Maj(a,b,c) |
| * h = g; g = f; f = e; e = d + T1; d = c; c = b; b = a; a + T1 + T2 |
| */ |
| for (t = 0; t <= 63; t++) { |
| T1 = h + sum1(e) + Ch(e, f, g) + sha_ko[t] + w[t]; |
| T2 = sum0(a) + Maj(a, b, c); |
| h = g; |
| g = f; |
| f = e; |
| e = d + T1; |
| d = c; |
| c = b; |
| b = a; |
| a = T1 + T2; |
| } |
| |
| /* |
| * step 4: |
| * H0 = a + H0, H1 = b + H1, H2 = c + H2, H3 = d + H3, H4 = e + H4 |
| */ |
| ctx->h[0] += a; |
| ctx->h[1] += b; |
| ctx->h[2] += c; |
| ctx->h[3] += d; |
| ctx->h[4] += e; |
| ctx->h[5] += f; |
| ctx->h[6] += g; |
| ctx->h[7] += h; |
| } |
| |
| static void sha256_do(sha256_ctx *ctx, const u8 *data32, u32 length) |
| { |
| u32 offset; |
| u16 num; |
| u32 bits = 0; |
| u32 w[64]; |
| u64 tmp; |
| |
| /* treat data in 64-byte chunks */ |
| for (offset = 0; length - offset >= 64; offset += 64) { |
| memcpy(w, data32 + offset, 64); |
| sha256_block((u32 *)w, ctx); |
| bits += (64 * 8); |
| } |
| |
| /* last block with less than 64 bytes */ |
| num = length - offset; |
| bits += (num << 3); |
| |
| memcpy(w, data32 + offset, num); |
| /* |
| * FIPS 180-4 5.1: Padding the Message |
| */ |
| ((u8 *)w)[num] = 0x80; |
| if (64 - (num + 1) > 0) |
| memset( &((u8 *)w)[num + 1], 0, 64 - (num + 1)); |
| |
| if (num >= 56) { |
| /* cannot append number of bits here */ |
| sha256_block((u32 *)w, ctx); |
| memset(w, 0, 60); |
| } |
| |
| /* write number of bits to end of block */ |
| tmp = cpu_to_be64(bits); |
| memcpy(&w[14], &tmp, 8); |
| |
| sha256_block(w, ctx); |
| |
| /* need to switch result's endianness */ |
| for (num = 0; num < 8; num++) |
| ctx->h[num] = cpu_to_be32(ctx->h[num]); |
| } |
| |
| void sha256(const u8 *data, u32 length, u8 *hash) |
| { |
| sha256_ctx ctx = { |
| .h = { |
| /* |
| * FIPS 180-4: 6.2.1 |
| * -> 5.3.3: initial hash value |
| */ |
| 0x6a09e667, |
| 0xbb67ae85, |
| 0x3c6ef372, |
| 0xa54ff53a, |
| 0x510e527f, |
| 0x9b05688c, |
| 0x1f83d9ab, |
| 0x5be0cd19 |
| } |
| }; |
| |
| sha256_do(&ctx, data, length); |
| memcpy(hash, ctx.h, sizeof(ctx.h)); |
| } |