diff options
Diffstat (limited to 'comm/third_party/botan/src/lib/pubkey/ed25519/sc_reduce.cpp')
| -rw-r--r-- | comm/third_party/botan/src/lib/pubkey/ed25519/sc_reduce.cpp | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/pubkey/ed25519/sc_reduce.cpp b/comm/third_party/botan/src/lib/pubkey/ed25519/sc_reduce.cpp new file mode 100644 index 0000000000..c69dd5eccd --- /dev/null +++ b/comm/third_party/botan/src/lib/pubkey/ed25519/sc_reduce.cpp @@ -0,0 +1,159 @@ +/* +* Ed25519 +* (C) 2017 Ribose Inc +* +* Based on the public domain code from SUPERCOP ref10 by +* Peter Schwabe, Daniel J. Bernstein, Niels Duif, Tanja Lange, Bo-Yin Yang +* +* Botan is released under the Simplified BSD License (see license.txt) +*/ + +#include <botan/internal/ed25519_internal.h> + +namespace Botan { + +/* +Input: + s[0]+256*s[1]+...+256^63*s[63] = s + +Output: + s[0]+256*s[1]+...+256^31*s[31] = s mod l + where l = 2^252 + 27742317777372353535851937790883648493. + Overwrites s in place. +*/ + +void sc_reduce(uint8_t* s) + { + const uint32_t MASK = 0x1fffff; + + int64_t s0 = MASK & load_3(s); + int64_t s1 = MASK & (load_4(s + 2) >> 5); + int64_t s2 = MASK & (load_3(s + 5) >> 2); + int64_t s3 = MASK & (load_4(s + 7) >> 7); + int64_t s4 = MASK & (load_4(s + 10) >> 4); + int64_t s5 = MASK & (load_3(s + 13) >> 1); + int64_t s6 = MASK & (load_4(s + 15) >> 6); + int64_t s7 = MASK & (load_3(s + 18) >> 3); + int64_t s8 = MASK & load_3(s + 21); + int64_t s9 = MASK & (load_4(s + 23) >> 5); + int64_t s10 = MASK & (load_3(s + 26) >> 2); + int64_t s11 = MASK & (load_4(s + 28) >> 7); + int64_t s12 = MASK & (load_4(s + 31) >> 4); + int64_t s13 = MASK & (load_3(s + 34) >> 1); + int64_t s14 = MASK & (load_4(s + 36) >> 6); + int64_t s15 = MASK & (load_3(s + 39) >> 3); + int64_t s16 = MASK & load_3(s + 42); + int64_t s17 = MASK & (load_4(s + 44) >> 5); + int64_t s18 = MASK & (load_3(s + 47) >> 2); + int64_t s19 = MASK & (load_4(s + 49) >> 7); + int64_t s20 = MASK & (load_4(s + 52) >> 4); + int64_t s21 = MASK & (load_3(s + 55) >> 1); + int64_t s22 = MASK & (load_4(s + 57) >> 6); + int64_t s23 = (load_4(s + 60) >> 3); + + redc_mul(s11, s12, s13, s14, s15, s16, s23); + redc_mul(s10, s11, s12, s13, s14, s15, s22); + redc_mul( s9, s10, s11, s12, s13, s14, s21); + redc_mul( s8, s9, s10, s11, s12, s13, s20); + redc_mul( s7, s8, s9, s10, s11, s12, s19); + redc_mul( s6, s7, s8, s9, s10, s11, s18); + + carry<21>(s6, s7); + carry<21>(s8, s9); + carry<21>(s10, s11); + carry<21>(s12, s13); + carry<21>(s14, s15); + carry<21>(s16, s17); + + carry<21>(s7, s8); + carry<21>(s9, s10); + carry<21>(s11, s12); + carry<21>(s13, s14); + carry<21>(s15, s16); + + redc_mul(s5, s6, s7, s8, s9, s10, s17); + redc_mul(s4, s5, s6, s7, s8, s9, s16); + redc_mul(s3, s4, s5, s6, s7, s8, s15); + redc_mul(s2, s3, s4, s5, s6, s7, s14); + redc_mul(s1, s2, s3, s4, s5, s6, s13); + redc_mul(s0, s1, s2, s3, s4, s5, s12); + + carry<21>(s0, s1); + carry<21>(s2, s3); + carry<21>(s4, s5); + carry<21>(s6, s7); + carry<21>(s8, s9); + carry<21>(s10, s11); + + carry<21>(s1, s2); + carry<21>(s3, s4); + carry<21>(s5, s6); + carry<21>(s7, s8); + carry<21>(s9, s10); + carry<21>(s11, s12); + + redc_mul(s0, s1, s2, s3, s4, s5, s12); + + carry0<21>(s0, s1); + carry0<21>(s1, s2); + carry0<21>(s2, s3); + carry0<21>(s3, s4); + carry0<21>(s4, s5); + carry0<21>(s5, s6); + carry0<21>(s6, s7); + carry0<21>(s7, s8); + carry0<21>(s8, s9); + carry0<21>(s9, s10); + carry0<21>(s10, s11); + carry0<21>(s11, s12); + + redc_mul(s0, s1, s2, s3, s4, s5, s12); + + carry0<21>(s0, s1); + carry0<21>(s1, s2); + carry0<21>(s2, s3); + carry0<21>(s3, s4); + carry0<21>(s4, s5); + carry0<21>(s5, s6); + carry0<21>(s6, s7); + carry0<21>(s7, s8); + carry0<21>(s8, s9); + carry0<21>(s9, s10); + carry0<21>(s10, s11); + carry0<21>(s11, s12); + + s[0] = static_cast<uint8_t>(s0 >> 0); + s[1] = static_cast<uint8_t>(s0 >> 8); + s[2] = static_cast<uint8_t>((s0 >> 16) | (s1 << 5)); + s[3] = static_cast<uint8_t>(s1 >> 3); + s[4] = static_cast<uint8_t>(s1 >> 11); + s[5] = static_cast<uint8_t>((s1 >> 19) | (s2 << 2)); + s[6] = static_cast<uint8_t>(s2 >> 6); + s[7] = static_cast<uint8_t>((s2 >> 14) | (s3 << 7)); + s[8] = static_cast<uint8_t>(s3 >> 1); + s[9] = static_cast<uint8_t>(s3 >> 9); + s[10] = static_cast<uint8_t>((s3 >> 17) | (s4 << 4)); + s[11] = static_cast<uint8_t>(s4 >> 4); + s[12] = static_cast<uint8_t>(s4 >> 12); + s[13] = static_cast<uint8_t>((s4 >> 20) | (s5 << 1)); + s[14] = static_cast<uint8_t>(s5 >> 7); + s[15] = static_cast<uint8_t>((s5 >> 15) | (s6 << 6)); + s[16] = static_cast<uint8_t>(s6 >> 2); + s[17] = static_cast<uint8_t>(s6 >> 10); + s[18] = static_cast<uint8_t>((s6 >> 18) | (s7 << 3)); + s[19] = static_cast<uint8_t>(s7 >> 5); + s[20] = static_cast<uint8_t>(s7 >> 13); + s[21] = static_cast<uint8_t>(s8 >> 0); + s[22] = static_cast<uint8_t>(s8 >> 8); + s[23] = static_cast<uint8_t>((s8 >> 16) | (s9 << 5)); + s[24] = static_cast<uint8_t>(s9 >> 3); + s[25] = static_cast<uint8_t>(s9 >> 11); + s[26] = static_cast<uint8_t>((s9 >> 19) | (s10 << 2)); + s[27] = static_cast<uint8_t>(s10 >> 6); + s[28] = static_cast<uint8_t>((s10 >> 14) | (s11 << 7)); + s[29] = static_cast<uint8_t>(s11 >> 1); + s[30] = static_cast<uint8_t>(s11 >> 9); + s[31] = static_cast<uint8_t>(s11 >> 17); + } + +} |