With no non-crypto API users of this function, we can move it into the generic crypto/ code where it belongs. Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> Cc: linux-crypto@xxxxxxxxxxxxxxx Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> --- crypto/sha1_generic.c | 114 +++++++++++++++++++++++++++++++++++ include/crypto/sha1.h | 10 --- lib/Makefile | 2 +- lib/sha1.c | 137 ------------------------------------------ 4 files changed, 115 insertions(+), 148 deletions(-) delete mode 100644 lib/sha1.c diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c index 325b57fe28dc..a2b019803561 100644 --- a/crypto/sha1_generic.c +++ b/crypto/sha1_generic.c @@ -16,9 +16,123 @@ #include <linux/module.h> #include <linux/mm.h> #include <linux/types.h> +#include <linux/bitops.h> +#include <linux/string.h> #include <crypto/sha1.h> #include <crypto/sha1_base.h> #include <asm/byteorder.h> +#include <asm/unaligned.h> + +#define SHA1_DIGEST_WORDS (SHA1_DIGEST_SIZE / 4) +#define SHA1_WORKSPACE_WORDS 16 + +/* + * 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); \ + TEMP = E; E = D; D = C; C = B; B = A; A = TEMP; } 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 ) + +/** + * sha1_transform - single block SHA1 transform (deprecated) + * + * @digest: 160 bit digest to update + * @data: 512 bits of data to hash + * @array: 16 words of workspace (see note) + * + * This function executes SHA-1's internal compression function. It updates the + * 160-bit internal state (@digest) with a single 512-bit data block (@data). + * + * Don't use this function. SHA-1 is no longer considered secure. And even if + * you do have to use SHA-1, this isn't the correct way to hash something with + * SHA-1 as this doesn't handle padding and finalization. + * + * 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 sha1_transform(__u32 *digest, const char *data, __u32 *array) +{ + __u32 A, B, C, D, E; + unsigned int i = 0; + + 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' */ + for (; i < 16; ++i) + T_0_15(i, A, B, C, D, E); + + /* Round 1 - tail. Input from 512-bit mixing array */ + for (; i < 20; ++i) + T_16_19(i, A, B, C, D, E); + + /* Round 2 */ + for (; i < 40; ++i) + T_20_39(i, A, B, C, D, E); + + /* Round 3 */ + for (; i < 60; ++i) + T_40_59(i, A, B, C, D, E); + + /* Round 4 */ + for (; i < 80; ++i) + T_60_79(i, A, B, C, D, E); + + digest[0] += A; + digest[1] += B; + digest[2] += C; + digest[3] += D; + digest[4] += E; +} const u8 sha1_zero_message_hash[SHA1_DIGEST_SIZE] = { 0xda, 0x39, 0xa3, 0xee, 0x5e, 0x6b, 0x4b, 0x0d, diff --git a/include/crypto/sha1.h b/include/crypto/sha1.h index 044ecea60ac8..118a3cad5eb3 100644 --- a/include/crypto/sha1.h +++ b/include/crypto/sha1.h @@ -33,14 +33,4 @@ extern int crypto_sha1_update(struct shash_desc *desc, const u8 *data, extern int crypto_sha1_finup(struct shash_desc *desc, const u8 *data, unsigned int len, u8 *hash); -/* - * An implementation of SHA-1's compression function. Don't use in new code! - * You shouldn't be using SHA-1, and even if you *have* to use SHA-1, this isn't - * the correct way to hash something with SHA-1 (use crypto_shash instead). - */ -#define SHA1_DIGEST_WORDS (SHA1_DIGEST_SIZE / 4) -#define SHA1_WORKSPACE_WORDS 16 -void sha1_init(__u32 *buf); -void sha1_transform(__u32 *digest, const char *data, __u32 *W); - #endif /* _CRYPTO_SHA1_H */ diff --git a/lib/Makefile b/lib/Makefile index 364c23f15578..83ac3f0c1fbe 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -29,7 +29,7 @@ endif lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o timerqueue.o xarray.o \ - idr.o extable.o sha1.o irq_regs.o argv_split.o \ + idr.o extable.o irq_regs.o argv_split.o \ flex_proportions.o ratelimit.o show_mem.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \ earlycpio.o seq_buf.o siphash.o dec_and_lock.o \ diff --git a/lib/sha1.c b/lib/sha1.c deleted file mode 100644 index 0494766fc574..000000000000 --- a/lib/sha1.c +++ /dev/null @@ -1,137 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * SHA1 routine optimized to do word accesses rather than byte accesses, - * and to avoid unnecessary copies into the context array. - * - * This was based on the git SHA1 implementation. - */ - -#include <linux/kernel.h> -#include <linux/export.h> -#include <linux/bitops.h> -#include <linux/string.h> -#include <crypto/sha1.h> -#include <asm/unaligned.h> - -/* - * 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); \ - TEMP = E; E = D; D = C; C = B; B = A; A = TEMP; } 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 ) - -/** - * sha1_transform - single block SHA1 transform (deprecated) - * - * @digest: 160 bit digest to update - * @data: 512 bits of data to hash - * @array: 16 words of workspace (see note) - * - * This function executes SHA-1's internal compression function. It updates the - * 160-bit internal state (@digest) with a single 512-bit data block (@data). - * - * Don't use this function. SHA-1 is no longer considered secure. And even if - * you do have to use SHA-1, this isn't the correct way to hash something with - * SHA-1 as this doesn't handle padding and finalization. - * - * 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. - */ -void sha1_transform(__u32 *digest, const char *data, __u32 *array) -{ - __u32 A, B, C, D, E; - unsigned int i = 0; - - 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' */ - for (; i < 16; ++i) - T_0_15(i, A, B, C, D, E); - - /* Round 1 - tail. Input from 512-bit mixing array */ - for (; i < 20; ++i) - T_16_19(i, A, B, C, D, E); - - /* Round 2 */ - for (; i < 40; ++i) - T_20_39(i, A, B, C, D, E); - - /* Round 3 */ - for (; i < 60; ++i) - T_40_59(i, A, B, C, D, E); - - /* Round 4 */ - for (; i < 80; ++i) - T_60_79(i, A, B, C, D, E); - - digest[0] += A; - digest[1] += B; - digest[2] += C; - digest[3] += D; - digest[4] += E; -} -EXPORT_SYMBOL(sha1_transform); - -/** - * sha1_init - initialize the vectors for a SHA1 digest - * @buf: vector to initialize - */ -void sha1_init(__u32 *buf) -{ - buf[0] = 0x67452301; - buf[1] = 0xefcdab89; - buf[2] = 0x98badcfe; - buf[3] = 0x10325476; - buf[4] = 0xc3d2e1f0; -} -EXPORT_SYMBOL(sha1_init); -- 2.34.1