From 6bd54d48f44b65464dd637add13292ca8189e1ef Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Thu, 13 Nov 2008 12:55:11 +0000 Subject: libbb/pw_encrypt_sha: -28 bytes --- libbb/pw_encrypt_sha.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'libbb') diff --git a/libbb/pw_encrypt_sha.c b/libbb/pw_encrypt_sha.c index 08b064750..3dbaeabc9 100644 --- a/libbb/pw_encrypt_sha.c +++ b/libbb/pw_encrypt_sha.c @@ -196,25 +196,23 @@ do { \ resptr = to64(resptr, w, N); \ } while (0) if (is_sha512 == '5') { - unsigned i = 0; - unsigned j = 10; - unsigned k = 20; - /* strange swap of one byte (see below why) */ - unsigned char alt_result_31 = alt_result[31]; - alt_result[31] = alt_result[1]; + int i = 0; + int j = 10; + int k = 20; while (1) { b64_from_24bit(alt_result[i], alt_result[j], alt_result[k], 4); if (i == 9) break; - i += 21; i = (((i >> 4) & 2) + i) & 0x1f; - j += 21; j = (((j >> 4) & 2) + j) & 0x1f; - k += 21; k = (((k >> 4) & 2) + k) & 0x1f; + /* if x - 9 produces < 0, subtract 2 more: + * ((i >> 8) << 1) is either 0 or binary 111111...1110 */ + i -= 9; i = (i & 0x1f) + ((i >> 8) << 1); + j -= 9; j = (j & 0x1f) + ((j >> 8) << 1); + k -= 9; k = (k & 0x1f) + ((k >> 8) << 1); } - b64_from_24bit(0, alt_result_31, alt_result[30], 3); + b64_from_24bit(0, alt_result[31], alt_result[30], 3); /* was: b64_from_24bit(alt_result[0], alt_result[10], alt_result[20], 4); b64_from_24bit(alt_result[21], alt_result[1], alt_result[11], 4); - ...............................^^^^^^^^^^^^^ why [1] and not [31]? b64_from_24bit(alt_result[12], alt_result[22], alt_result[2], 4); b64_from_24bit(alt_result[3], alt_result[13], alt_result[23], 4); b64_from_24bit(alt_result[24], alt_result[4], alt_result[14], 4); -- cgit v1.2.3