With SHA-1 no longer being used for anything performance oriented, and also soon to be phased out entirely, we can make up for the space added by unrolled BLAKE2s by simply re-rolling SHA-1. Since SHA-1 is so much more complex, re-rolling it more or less takes care of the code size added by BLAKE2s. And eventually, hopefully we'll see SHA-1 removed entirely from most small kernel builds.
Cc: Geert Uytterhoeven <[email protected]> Cc: Herbert Xu <[email protected]> Cc: Ard Biesheuvel <[email protected]> Signed-off-by: Jason A. Donenfeld <[email protected]> --- lib/sha1.c | 117 ++++++++++++----------------------------------------- 1 file changed, 25 insertions(+), 92 deletions(-) diff --git a/lib/sha1.c b/lib/sha1.c index 9bd1935a1472..f2acfa294e64 100644 --- a/lib/sha1.c +++ b/lib/sha1.c @@ -9,6 +9,7 @@ #include <linux/kernel.h> #include <linux/export.h> #include <linux/bitops.h> +#include <linux/string.h> #include <crypto/sha1.h> #include <asm/unaligned.h> @@ -83,109 +84,41 @@ */ void sha1_transform(__u32 *digest, const char *data, __u32 *array) { - __u32 A, B, C, D, E; + u32 d[5]; + unsigned int i = 0; - A = digest[0]; - B = digest[1]; - C = digest[2]; - D = digest[3]; - E = digest[4]; + memcpy(d, digest, sizeof(d)); /* 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); + for (; i < 16; ++i) + T_0_15(i, d[(-6 - i) % 5], d[(-5 - i) % 5], + d[(-4 - i) % 5], d[(-3 - i) % 5], d[(-2 - i) % 5]); /* 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); + for (; i < 20; ++i) + T_16_19(i, d[(-6 - i) % 5], d[(-5 - i) % 5], + d[(-4 - i) % 5], d[(-3 - i) % 5], d[(-2 - i) % 5]); /* 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); + for (; i < 40; ++i) + T_20_39(i, d[(-6 - i) % 5], d[(-5 - i) % 5], + d[(-4 - i) % 5], d[(-3 - i) % 5], d[(-2 - i) % 5]); /* 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); + for (; i < 60; ++i) + T_40_59(i, d[(-6 - i) % 5], d[(-5 - i) % 5], + d[(-4 - i) % 5], d[(-3 - i) % 5], d[(-2 - i) % 5]); /* 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; + for (; i < 80; ++i) + T_60_79(i, d[(-6 - i) % 5], d[(-5 - i) % 5], + d[(-4 - i) % 5], d[(-3 - i) % 5], d[(-2 - i) % 5]); + + digest[0] += d[0]; + digest[1] += d[1]; + digest[2] += d[2]; + digest[3] += d[3]; + digest[4] += d[4]; } EXPORT_SYMBOL(sha1_transform); -- 2.34.1
