From: Luke Kenneth Casson Leighton Date: Wed, 21 Feb 2024 12:17:32 +0000 (+0000) Subject: bug 1151: add beginnings of curve25519_mul X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8051365d9b8c82681b2799e8e0c3685bdc147dd4;p=openpower-isa.git bug 1151: add beginnings of curve25519_mul https://bugs.libre-soc.org/show_bug.cgi?id=773#c1 --- diff --git a/src/openpower/decoder/isa/ed25519/curve25519_mul.py b/src/openpower/decoder/isa/ed25519/curve25519_mul.py new file mode 100644 index 00000000..1b6d6390 --- /dev/null +++ b/src/openpower/decoder/isa/ed25519/curve25519_mul.py @@ -0,0 +1,84 @@ +""" +Copyright (C) 2023 2024 Luke Kenneth Casson Leighton +License: LGPLv3+ +Funding: NLnet NGI-ASSURE Project funded under EU grant agreement No 957073. +""" + +""" +start here... https://bugs.libre-soc.org/show_bug.cgi?id=773#c1 + +t[0] = r0 * s0 +t[1] = r0 * s1 + r1 * s0; +t[2] = r0 * s2 + r1 * s1 + r2 * s0; +t[3] = r0 * s3 + r1 * s2 + r2 * s1 + r3 * s0; +t[4] = r0 * s4 + r1 * s3 + r2 * s2 + r3 * s1 + r4 * s0; + + r1 *= 19; + r2 *= 19; + r3 *= 19; + r4 *= 19; + +t[0] += r4 * s1 + r3 * s2 + r2 * s3 + r1 * s4; +t[1] += r4 * s2 + r3 * s3 + r2 * s4; +t[2] += r4 * s3 + r3 * s4; +t[3] += r4 * s4; + + r0 = lo128(t[0]) & reduce_mask_51; shr128(c, t[0], 51); +add128_64(t[1], c) r1 = lo128(t[1]) & reduce_mask_51; shr128(c, t[1], 51); +add128_64(t[2], c) r2 = lo128(t[2]) & reduce_mask_51; shr128(c, t[2], 51); +add128_64(t[3], c) r3 = lo128(t[3]) & reduce_mask_51; shr128(c, t[3], 51); +add128_64(t[4], c) r4 = lo128(t[4]) & reduce_mask_51; shr128(c, t[4], 51); +r0 += c * 19; c = r0 >> 51; r0 = r0 & reduce_mask_51; +r1 += c; + +""" + +import random + +def curve25519_mul(r, s): + + t = [0] * 5 + + for i in range(5): + print("t%d += " % i, end='') + for j in range(i+1): + sidx = i-j + print("r%d*s%d + " % (i, sidx), end='') + t[i] += r[i] * s[sidx] + print() + + for i in range(1,5): + r[i] *= 19 + + print() + for i in range(4,0,-1): + tidx = 4-i + print("t%d += " % tidx, end='') + for j in range(i): + jidx, sidx = 4-j, 5-(i-j) + print("r%d*s%d + " % (jidx, sidx), end='') + t[tidx] += r[jidx] * s[sidx] + print() + + # this is the one where i *think* it possible to do some sort + # of single-operation similar to dsld. + + c = 0 + for i in range(5): + add128_64(t[i], c); + r[i] = lo128(t[i]) & reduce_mask_51; + shr128(c, t[i], 51); + + r[0] += c * 19; c = r[0] >> 51; r[0] = r[0] & reduce_mask_51; + r[1] += c; + +if __name__ == '__main__': + random.seed(2) # set the same seed (consistent test) + r, s = [], [] + for j in range(5): + r.append(random.randint(0, 2^50)) + s.append(random.randint(0, 2^50)) + print ("r", r) + print ("s", s) + t = curve25519_mul(r, s) + print ("t", t)