/* * Cryptographic API. * * SHA1 Secure Hash Algorithm. * * Derived from cryptoapi implementation, adapted for in-place * scatterlist interface. * * Copyright (c) Alan Smithee. * Copyright (c) Andrew McDonald * Copyright (c) Jean-Francois Dive * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ #include #include #include #include #include #include #include #include #define SHA_WORKSPACE_WORDS 16 static int sha1_init(struct digest *desc) { struct sha1_state *ctx = digest_ctx(desc); ctx->count = 0; ctx->state[0] = SHA1_H0; ctx->state[1] = SHA1_H1; ctx->state[2] = SHA1_H2; ctx->state[3] = SHA1_H3; ctx->state[4] = SHA1_H4; return 0; } /* * If you have 32 registers or more, the compiler can (and should) * try to change the array[] accesses into registers. However, on * machines with less than ~25 registers, that won't really work, * and at least gcc will make an unholy mess of it. * * So to avoid that mess which just slows things down, we force * the stores to memory to actually happen (we might be better off * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as * suggested by Artur Skawina - that will also make gcc unable to * try to do the silly "optimize away loads" part because it won't * see what the value will be). * * Ben Herrenschmidt reports that on PPC, the C version comes close * to the optimized asm with this (ie on PPC you don't want that * 'volatile', since there are lots of registers). * * On ARM we get the best code generation by forcing a full memory barrier * between each SHA_ROUND, otherwise gcc happily get wild with spilling and * the stack frame size simply explode and performance goes down the drain. */ #ifdef CONFIG_X86 #define setW(x, val) (*(volatile __u32 *)&W(x) = (val)) #elif defined(CONFIG_ARM) #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0) #else #define setW(x, val) (W(x) = (val)) #endif /* This "rolls" over the 512-bit array */ #define W(x) (array[(x)&15]) /* * Where do we get the source from? The first 16 iterations get it from * the input data, the next mix it from the 512-bit array. */ #define SHA_SRC(t) get_unaligned_be32((__u32 *)data + t) #define SHA_MIX(t) rol32(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1) #define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \ __u32 TEMP = input(t); setW(t, TEMP); \ E += TEMP + rol32(A,5) + (fn) + (constant); \ B = ror32(B, 2); } while (0) #define T_0_15(t, A, B, C, D, E) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) #define T_16_19(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) #define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E ) #define T_40_59(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc, A, B, C, D, E ) #define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E ) /** * sha_transform - single block SHA1 transform * * @digest: 160 bit digest to update * @data: 512 bits of data to hash * @array: 16 words of workspace (see note) * * This function generates a SHA1 digest for a single 512-bit block. * Be warned, it does not handle padding and message digest, do not * confuse it with the full FIPS 180-1 digest algorithm for variable * length messages. * * Note: If the hash is security sensitive, the caller should be sure * to clear the workspace. This is left to the caller to avoid * unnecessary clears between chained hashing operations. */ static void sha_transform(__u32 *digest, const char *data, __u32 *array) { __u32 A, B, C, D, E; A = digest[0]; B = digest[1]; C = digest[2]; D = digest[3]; E = digest[4]; /* Round 1 - iterations 0-16 take their input from 'data' */ T_0_15( 0, A, B, C, D, E); T_0_15( 1, E, A, B, C, D); T_0_15( 2, D, E, A, B, C); T_0_15( 3, C, D, E, A, B); T_0_15( 4, B, C, D, E, A); T_0_15( 5, A, B, C, D, E); T_0_15( 6, E, A, B, C, D); T_0_15( 7, D, E, A, B, C); T_0_15( 8, C, D, E, A, B); T_0_15( 9, B, C, D, E, A); T_0_15(10, A, B, C, D, E); T_0_15(11, E, A, B, C, D); T_0_15(12, D, E, A, B, C); T_0_15(13, C, D, E, A, B); T_0_15(14, B, C, D, E, A); T_0_15(15, A, B, C, D, E); /* Round 1 - tail. Input from 512-bit mixing array */ T_16_19(16, E, A, B, C, D); T_16_19(17, D, E, A, B, C); T_16_19(18, C, D, E, A, B); T_16_19(19, B, C, D, E, A); /* Round 2 */ T_20_39(20, A, B, C, D, E); T_20_39(21, E, A, B, C, D); T_20_39(22, D, E, A, B, C); T_20_39(23, C, D, E, A, B); T_20_39(24, B, C, D, E, A); T_20_39(25, A, B, C, D, E); T_20_39(26, E, A, B, C, D); T_20_39(27, D, E, A, B, C); T_20_39(28, C, D, E, A, B); T_20_39(29, B, C, D, E, A); T_20_39(30, A, B, C, D, E); T_20_39(31, E, A, B, C, D); T_20_39(32, D, E, A, B, C); T_20_39(33, C, D, E, A, B); T_20_39(34, B, C, D, E, A); T_20_39(35, A, B, C, D, E); T_20_39(36, E, A, B, C, D); T_20_39(37, D, E, A, B, C); T_20_39(38, C, D, E, A, B); T_20_39(39, B, C, D, E, A); /* Round 3 */ T_40_59(40, A, B, C, D, E); T_40_59(41, E, A, B, C, D); T_40_59(42, D, E, A, B, C); T_40_59(43, C, D, E, A, B); T_40_59(44, B, C, D, E, A); T_40_59(45, A, B, C, D, E); T_40_59(46, E, A, B, C, D); T_40_59(47, D, E, A, B, C); T_40_59(48, C, D, E, A, B); T_40_59(49, B, C, D, E, A); T_40_59(50, A, B, C, D, E); T_40_59(51, E, A, B, C, D); T_40_59(52, D, E, A, B, C); T_40_59(53, C, D, E, A, B); T_40_59(54, B, C, D, E, A); T_40_59(55, A, B, C, D, E); T_40_59(56, E, A, B, C, D); T_40_59(57, D, E, A, B, C); T_40_59(58, C, D, E, A, B); T_40_59(59, B, C, D, E, A); /* Round 4 */ T_60_79(60, A, B, C, D, E); T_60_79(61, E, A, B, C, D); T_60_79(62, D, E, A, B, C); T_60_79(63, C, D, E, A, B); T_60_79(64, B, C, D, E, A); T_60_79(65, A, B, C, D, E); T_60_79(66, E, A, B, C, D); T_60_79(67, D, E, A, B, C); T_60_79(68, C, D, E, A, B); T_60_79(69, B, C, D, E, A); T_60_79(70, A, B, C, D, E); T_60_79(71, E, A, B, C, D); T_60_79(72, D, E, A, B, C); T_60_79(73, C, D, E, A, B); T_60_79(74, B, C, D, E, A); T_60_79(75, A, B, C, D, E); T_60_79(76, E, A, B, C, D); T_60_79(77, D, E, A, B, C); T_60_79(78, C, D, E, A, B); T_60_79(79, B, C, D, E, A); digest[0] += A; digest[1] += B; digest[2] += C; digest[3] += D; digest[4] += E; } static int sha1_update(struct digest *desc, const void *data, unsigned long len) { struct sha1_state *sctx = digest_ctx(desc); unsigned int partial, done; const u8 *src; partial = sctx->count % SHA1_BLOCK_SIZE; sctx->count += len; done = 0; src = data; if ((partial + len) >= SHA1_BLOCK_SIZE) { u32 temp[SHA_WORKSPACE_WORDS]; if (partial) { done = -partial; memcpy(sctx->buffer + partial, data, done + SHA1_BLOCK_SIZE); src = sctx->buffer; } do { sha_transform(sctx->state, src, temp); done += SHA1_BLOCK_SIZE; src = data + done; } while (done + SHA1_BLOCK_SIZE <= len); memset(temp, 0, sizeof(temp)); partial = 0; } memcpy(sctx->buffer + partial, src, len - done); return 0; } static int sha1_final(struct digest *desc, unsigned char *md) { struct sha1_state *sctx = digest_ctx(desc); __be32 *dst = (__be32 *)md; u32 i, index, padlen; __be64 bits; static const u8 padding[64] = { 0x80, }; bits = cpu_to_be64(sctx->count << 3); /* Pad out to 56 mod 64 */ index = sctx->count & 0x3f; padlen = (index < 56) ? (56 - index) : ((64+56) - index); sha1_update(desc, padding, padlen); /* Append length */ sha1_update(desc, (const u8 *)&bits, sizeof(bits)); /* Store state in digest */ for (i = 0; i < 5; i++) dst[i] = cpu_to_be32(sctx->state[i]); /* Wipe context */ memset(sctx, 0, sizeof *sctx); return 0; } static struct digest_algo m = { .base = { .name = "sha1", .driver_name = "sha1-generic", .priority = 0, .algo = HASH_ALGO_SHA1, }, .init = sha1_init, .update = sha1_update, .final = sha1_final, .digest = digest_generic_digest, .verify = digest_generic_verify, .length = SHA1_DIGEST_SIZE, .ctx_length = sizeof(struct sha1_state), }; static int sha1_digest_register(void) { return digest_algo_register(&m); } device_initcall(sha1_digest_register);