From d3430352e7a38cffd796c645281d9433f0ea8f00 Mon Sep 17 00:00:00 2001 From: David Phillips Date: Sun, 28 May 2017 18:58:15 +1200 Subject: Remove ssse3 algorithm, tighten decoder --- onion_base32.c | 81 +++++----------------------------------------------------- onion_base32.h | 4 --- 2 files changed, 7 insertions(+), 78 deletions(-) diff --git a/onion_base32.c b/onion_base32.c index 6f1713d..7863f8c 100644 --- a/onion_base32.c +++ b/onion_base32.c @@ -37,17 +37,16 @@ onion_base32(char output[16], unsigned char sum[20]) { unsigned char base32_dec_single(char b) { - int ret = 0; + if (b >= 'a' && b <= 'z') + return b - 'a'; + else if (b >= '2' && b <= '7') + return b - '2' + 26; - if (b < 'a') - ret = b - '2' + 26; - else - ret = b - 'a'; - - printf("%d «%d»\n", ret, b); - return ret; + return 0; } +/* Simple algorithm to decode a 16-byte base32 sequence to the 10 bytes + * it represents, placing the result in dec */ void onion_base32_dec(unsigned char dec[10], char base32[16]) { @@ -61,70 +60,4 @@ onion_base32_dec(unsigned char dec[10], char base32[16]) dec[c++] = base32_dec_single(base32[i+4]) << 7 | base32_dec_single(base32[i+5]) << 2 | base32_dec_single(base32[i+6]) >> 3; dec[c++] = base32_dec_single(base32[i+7]) | base32_dec_single(base32[i+6]) << 5; } - -} -#ifdef __SSSE3__ -#include - -/* A slightly-parallel base32 algorithm using SSSE3 - * Note: This is not a general base32 algorithm; it outputs only the - * first 16 base32 symbols of the input buffer, using only the first - * 20 bytes of that buffer. - * - * Somewhat inspired by http://www.alfredklomp.com/programming/sse-base64/ - */ -void -onion_base32_ssse3(char output[16], unsigned char sum[20]) { - __m128i res; - __m128i ssum; - __m128i masklow5; - __m128i lmask, l; - __m128i nmask, n; - - ssum = _mm_loadu_si128((__m128i*)sum); - - /* FIXME seems a little hacky */ - masklow5 = _mm_set1_epi32(0x1F000000); - masklow5 = _mm_slli_epi64(masklow5, 32); - - ssum = _mm_shuffle_epi8(ssum, - _mm_setr_epi8(9,9,9,9,8,7,6,5,4,4,4,4,3,2,1,0 )); - - /* remember how I said "slightly parallel" ? */ - res = _mm_srli_epi64(ssum, 3) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - res |= _mm_srli_epi64(ssum, 6) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - res |= _mm_srli_epi64(ssum, 9) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - res |= _mm_srli_epi64(ssum, 12) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - res |= _mm_srli_epi64(ssum, 15) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - res |= _mm_srli_epi64(ssum, 18) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - res |= _mm_srli_epi64(ssum, 21) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - res |= _mm_srli_epi64(ssum, 24) & masklow5; - masklow5 = _mm_srli_epi64(masklow5, 8); - - - res = _mm_shuffle_epi8(res, - _mm_setr_epi8(15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)); - - lmask = _mm_cmplt_epi8(res, _mm_set1_epi8(26)); - nmask = _mm_andnot_si128(lmask, _mm_cmplt_epi8(res, _mm_set1_epi8(32))); - - l = lmask & _mm_add_epi8(res, _mm_set1_epi8('a')); - n = nmask & _mm_add_epi8(res, _mm_set1_epi8('2' - 26)); - - _mm_storeu_si128((__m128i*)output, l|n); } -#endif /* ifdef __SSSE3__ */ diff --git a/onion_base32.h b/onion_base32.h index 23e7bd2..854c6f9 100644 --- a/onion_base32.h +++ b/onion_base32.h @@ -1,7 +1,3 @@ int check_base32(char *); void onion_base32(char [16], unsigned char (*)); void onion_base32_dec(unsigned char [10], char[16]); - -#ifdef __SSSE3__ -void onion_base32_ssse3(char [16], unsigned char (*)); -#endif -- cgit v1.1