From b8935d00b0a60be24ee9073349c2a185cebbacd4 Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Sun, 15 Jan 2017 20:16:27 +0100
Subject: sha512: use larger constant table only if sha512 is in fact selected

function                                             old     new   delta
sha_K                                                640     256    -384

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 libbb/hash_md5_sha.c | 112 ++++++++++++++++++++++++++++++---------------------
 1 file changed, 66 insertions(+), 46 deletions(-)

(limited to 'libbb')

diff --git a/libbb/hash_md5_sha.c b/libbb/hash_md5_sha.c
index 7e7d8da2f..d325584d7 100644
--- a/libbb/hash_md5_sha.c
+++ b/libbb/hash_md5_sha.c
@@ -9,6 +9,8 @@
 
 #include "libbb.h"
 
+#define NEED_SHA512 (ENABLE_SHA512SUM || ENABLE_USE_BB_CRYPT_SHA)
+
 /* gcc 4.2.1 optimizes rotr64 better with inline than with macro
  * (for rotX32, there is no difference). Why? My guess is that
  * macro requires clever common subexpression elimination heuristics
@@ -564,48 +566,59 @@ static void FAST_FUNC sha1_process_block64(sha1_ctx_t *ctx)
  * are the most significant half of first 64 elements
  * of the same array.
  */
-static const uint64_t sha_K[80] = {
-	0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
-	0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
-	0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
-	0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
-	0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
-	0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
-	0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
-	0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
-	0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
-	0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
-	0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
-	0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
-	0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
-	0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
-	0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
-	0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
-	0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
-	0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
-	0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
-	0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
-	0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
-	0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
-	0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
-	0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
-	0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
-	0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
-	0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
-	0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
-	0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
-	0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
-	0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
-	0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
-	0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, /* [64]+ are used for sha512 only */
-	0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
-	0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
-	0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
-	0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
-	0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
-	0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
-	0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
+#undef K
+#if NEED_SHA512
+typedef uint64_t sha_K_int;
+# define K(v) v
+#else
+typedef uint32_t sha_K_int;
+# define K(v) (uint32_t)(v >> 32)
+#endif
+static const sha_K_int sha_K[] = {
+	K(0x428a2f98d728ae22ULL), K(0x7137449123ef65cdULL),
+	K(0xb5c0fbcfec4d3b2fULL), K(0xe9b5dba58189dbbcULL),
+	K(0x3956c25bf348b538ULL), K(0x59f111f1b605d019ULL),
+	K(0x923f82a4af194f9bULL), K(0xab1c5ed5da6d8118ULL),
+	K(0xd807aa98a3030242ULL), K(0x12835b0145706fbeULL),
+	K(0x243185be4ee4b28cULL), K(0x550c7dc3d5ffb4e2ULL),
+	K(0x72be5d74f27b896fULL), K(0x80deb1fe3b1696b1ULL),
+	K(0x9bdc06a725c71235ULL), K(0xc19bf174cf692694ULL),
+	K(0xe49b69c19ef14ad2ULL), K(0xefbe4786384f25e3ULL),
+	K(0x0fc19dc68b8cd5b5ULL), K(0x240ca1cc77ac9c65ULL),
+	K(0x2de92c6f592b0275ULL), K(0x4a7484aa6ea6e483ULL),
+	K(0x5cb0a9dcbd41fbd4ULL), K(0x76f988da831153b5ULL),
+	K(0x983e5152ee66dfabULL), K(0xa831c66d2db43210ULL),
+	K(0xb00327c898fb213fULL), K(0xbf597fc7beef0ee4ULL),
+	K(0xc6e00bf33da88fc2ULL), K(0xd5a79147930aa725ULL),
+	K(0x06ca6351e003826fULL), K(0x142929670a0e6e70ULL),
+	K(0x27b70a8546d22ffcULL), K(0x2e1b21385c26c926ULL),
+	K(0x4d2c6dfc5ac42aedULL), K(0x53380d139d95b3dfULL),
+	K(0x650a73548baf63deULL), K(0x766a0abb3c77b2a8ULL),
+	K(0x81c2c92e47edaee6ULL), K(0x92722c851482353bULL),
+	K(0xa2bfe8a14cf10364ULL), K(0xa81a664bbc423001ULL),
+	K(0xc24b8b70d0f89791ULL), K(0xc76c51a30654be30ULL),
+	K(0xd192e819d6ef5218ULL), K(0xd69906245565a910ULL),
+	K(0xf40e35855771202aULL), K(0x106aa07032bbd1b8ULL),
+	K(0x19a4c116b8d2d0c8ULL), K(0x1e376c085141ab53ULL),
+	K(0x2748774cdf8eeb99ULL), K(0x34b0bcb5e19b48a8ULL),
+	K(0x391c0cb3c5c95a63ULL), K(0x4ed8aa4ae3418acbULL),
+	K(0x5b9cca4f7763e373ULL), K(0x682e6ff3d6b2b8a3ULL),
+	K(0x748f82ee5defb2fcULL), K(0x78a5636f43172f60ULL),
+	K(0x84c87814a1f0ab72ULL), K(0x8cc702081a6439ecULL),
+	K(0x90befffa23631e28ULL), K(0xa4506cebde82bde9ULL),
+	K(0xbef9a3f7b2c67915ULL), K(0xc67178f2e372532bULL),
+#if NEED_SHA512  /* [64]+ are used for sha512 only */
+	K(0xca273eceea26619cULL), K(0xd186b8c721c0c207ULL),
+	K(0xeada7dd6cde0eb1eULL), K(0xf57d4f7fee6ed178ULL),
+	K(0x06f067aa72176fbaULL), K(0x0a637dc5a2c898a6ULL),
+	K(0x113f9804bef90daeULL), K(0x1b710b35131c471bULL),
+	K(0x28db77f523047d84ULL), K(0x32caab7b40c72493ULL),
+	K(0x3c9ebe0a15c9bebcULL), K(0x431d67c49c100d4cULL),
+	K(0x4cc5d4becb3e42b6ULL), K(0x597f299cfc657e2aULL),
+	K(0x5fcb6fab3ad6faecULL), K(0x6c44198c4a475817ULL),
+#endif
 };
+#undef K
 
 #undef Ch
 #undef Maj
@@ -649,7 +662,7 @@ static void FAST_FUNC sha256_process_block64(sha256_ctx_t *ctx)
 		 * (I hope compiler is clever enough to just fetch
 		 * upper half)
 		 */
-		uint32_t K_t = sha_K[t] >> 32;
+		uint32_t K_t = NEED_SHA512 ? (sha_K[t] >> 32) : sha_K[t];
 		uint32_t T1 = h + S1(e) + Ch(e, f, g) + K_t + W[t];
 		uint32_t T2 = S0(a) + Maj(a, b, c);
 		h = g;
@@ -679,6 +692,7 @@ static void FAST_FUNC sha256_process_block64(sha256_ctx_t *ctx)
 	ctx->hash[7] += h;
 }
 
+#if NEED_SHA512
 static void FAST_FUNC sha512_process_block128(sha512_ctx_t *ctx)
 {
 	unsigned t;
@@ -740,7 +754,7 @@ static void FAST_FUNC sha512_process_block128(sha512_ctx_t *ctx)
 	ctx->hash[6] += g;
 	ctx->hash[7] += h;
 }
-
+#endif /* NEED_SHA512 */
 
 void FAST_FUNC sha1_begin(sha1_ctx_t *ctx)
 {
@@ -765,6 +779,7 @@ static const uint32_t init256[] = {
 	0x1f83d9ab,
 	0x5be0cd19,
 };
+#if NEED_SHA512
 static const uint32_t init512_lo[] = {
 	0,
 	0,
@@ -777,6 +792,7 @@ static const uint32_t init512_lo[] = {
 	0xfb41bd6b,
 	0x137e2179,
 };
+#endif /* NEED_SHA512 */
 
 /* Initialize structure containing state of computation.
    (FIPS 180-2:5.3.2)  */
@@ -787,6 +803,7 @@ void FAST_FUNC sha256_begin(sha256_ctx_t *ctx)
 	ctx->process_block = sha256_process_block64;
 }
 
+#if NEED_SHA512
 /* Initialize structure containing state of computation.
    (FIPS 180-2:5.3.3)  */
 void FAST_FUNC sha512_begin(sha512_ctx_t *ctx)
@@ -810,7 +827,7 @@ void FAST_FUNC sha512_hash(sha512_ctx_t *ctx, const void *buffer, size_t len)
 	ctx->total64[0] += len;
 	if (ctx->total64[0] < len)
 		ctx->total64[1]++;
-#if 0
+# if 0
 	remaining = 128 - bufpos;
 
 	/* Hash whole blocks */
@@ -825,7 +842,7 @@ void FAST_FUNC sha512_hash(sha512_ctx_t *ctx, const void *buffer, size_t len)
 
 	/* Save last, partial blosk */
 	memcpy(ctx->wbuffer + bufpos, buffer, len);
-#else
+# else
 	while (1) {
 		remaining = 128 - bufpos;
 		if (remaining > len)
@@ -843,8 +860,9 @@ void FAST_FUNC sha512_hash(sha512_ctx_t *ctx, const void *buffer, size_t len)
 		sha512_process_block128(ctx);
 		/*bufpos = 0; - already is */
 	}
-#endif
+# endif
 }
+#endif /* NEED_SHA512 */
 
 /* Used also for sha256 */
 void FAST_FUNC sha1_end(sha1_ctx_t *ctx, void *resbuf)
@@ -864,6 +882,7 @@ void FAST_FUNC sha1_end(sha1_ctx_t *ctx, void *resbuf)
 	memcpy(resbuf, ctx->hash, sizeof(ctx->hash[0]) * hash_size);
 }
 
+#if NEED_SHA512
 void FAST_FUNC sha512_end(sha512_ctx_t *ctx, void *resbuf)
 {
 	unsigned bufpos = ctx->total64[0] & 127;
@@ -897,6 +916,7 @@ void FAST_FUNC sha512_end(sha512_ctx_t *ctx, void *resbuf)
 	}
 	memcpy(resbuf, ctx->hash, sizeof(ctx->hash));
 }
+#endif /* NEED_SHA512 */
 
 
 /*
-- 
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