constantine/tests/math/t_bigints.nim

640 lines
20 KiB
Nim

# Constantine
# Copyright (c) 2018-2019 Status Research & Development GmbH
# Copyright (c) 2020-Present Mamy André-Ratsimbazafy
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at http://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at http://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
import
# Standard library
std/unittest,
# Internal
../../constantine/math/io/io_bigints,
../../constantine/math/arithmetic,
../../constantine/platforms/abstractions,
# Test utilities,
support/canaries
echo "\n------------------------------------------------------\n"
proc mainArith() =
suite "isZero" & " [" & $WordBitWidth & "-bit mode]":
test "isZero for zero":
var x: BigInt[128]
check: x.isZero().bool
test "isZero for non-zero":
block:
let x = fromHex(BigInt[128], "0x00000000000000000000000000000001")
check: not x.isZero().bool
block:
let x = fromHex(BigInt[128], "0x00000000000000010000000000000000")
check: not x.isZero().bool
block:
let x = fromHex(BigInt[128], "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF")
check: not x.isZero().bool
test "isZero for zero (compile-time)":
const x = BigInt[128]()
check: static(x.isZero().bool)
test "isZero for non-zero (compile-time)":
block:
const x = fromHex(BigInt[128], "0x00000000000000000000000000000001")
check: static(not x.isZero().bool)
block:
const x = fromHex(BigInt[128], "0x00000000000000010000000000000000")
check: static(not x.isZero().bool)
block:
const x = fromHex(BigInt[128], "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF")
check: static(not x.isZero().bool)
suite "Arithmetic operations - Addition" & " [" & $WordBitWidth & "-bit mode]":
test "Adding 2 zeros":
var a = fromHex(BigInt[128], "0x00000000000000000000000000000000")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000000")
let carry = a.cadd(b, CtTrue)
check: a.isZero().bool
test "Adding 1 zero - real addition":
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000000")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let carry = a.cadd(b, CtTrue)
let c = fromHex(BigInt[128], "0x00000000000000000000000000000001")
check:
bool(a == c)
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000000")
let carry = a.cadd(b, CtTrue)
let c = fromHex(BigInt[128], "0x00000000000000000000000000000001")
check:
bool(a == c)
test "Adding 1 zero - fake addition":
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000000")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let carry = a.cadd(b, CtFalse)
let c = a
check:
bool(a == c)
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000000")
let carry = a.cadd(b, CtFalse)
let c = a
check:
bool(a == c)
test "Adding non-zeros - real addition":
block:
var a = fromHex(BigInt[128], "0x00000000000000010000000000000000")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let carry = a.cadd(b, CtTrue)
let c = fromHex(BigInt[128], "0x00000000000000010000000000000001")
check:
bool(a == c)
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let b = fromHex(BigInt[128], "0x00000000000000010000000000000000")
let carry = a.cadd(b, CtTrue)
let c = fromHex(BigInt[128], "0x00000000000000010000000000000001")
check:
bool(a == c)
test "Adding non-zeros - fake addition":
block:
var a = fromHex(BigInt[128], "0x00000000000000010000000000000000")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let carry = a.cadd(b, CtFalse)
let c = a
check:
bool(a == c)
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let b = fromHex(BigInt[128], "0x00000000000000010000000000000000")
let carry = a.cadd(b, CtFalse)
let c = a
check:
bool(a == c)
test "Addition limbs carry":
block:
var a = fromHex(BigInt[128], "0x00000000FFFFFFFFFFFFFFFFFFFFFFFE")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let carry = a.cadd(b, CtTrue)
let c = fromHex(BigInt[128], "0x00000000FFFFFFFFFFFFFFFFFFFFFFFF")
check:
bool(a == c)
not bool(carry)
block:
var a = fromHex(BigInt[128], "0x00000000FFFFFFFFFFFFFFFFFFFFFFFF")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let carry = a.cadd(b, CtTrue)
let c = fromHex(BigInt[128], "0x00000001000000000000000000000000")
check:
bool(a == c)
not bool(carry)
suite "BigInt + SecretWord" & " [" & $WordBitWidth & "-bit mode]":
test "Addition limbs carry":
block: # P256 / 2
var a = BigInt[256].fromhex"0x7fffffff800000008000000000000000000000007fffffffffffffffffffffff"
let expected = BigInt[256].fromHex"7fffffff80000000800000000000000000000000800000000000000000000000"
discard a.add(One)
check: bool(a == expected)
proc mainMul() =
suite "Multi-precision multiplication" & " [" & $WordBitWidth & "-bit mode]":
test "Same size operand into double size result":
block:
var r = canary(BigInt[256])
let a = BigInt[128].fromHex"0x12345678FF11FFAA00321321CAFECAFE"
let b = BigInt[128].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
let expected = BigInt[256].fromHex"fd5bdef43d64113f371ab5d8843beca889c07fd549b84d8a5001a8f102e0722"
r.prod(a, b)
check: bool(r == expected)
r.prod(b, a)
check: bool(r == expected)
test "Different size into large result":
block:
var r = canary(BigInt[200])
let a = BigInt[29].fromHex"0x12345678"
let b = BigInt[128].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
let expected = BigInt[200].fromHex"fd5bdee65f787f665f787f665f787f65621ca08"
r.prod(a, b)
check: bool(r == expected)
r.prod(b, a)
check: bool(r == expected)
test "Destination is properly zero-padded if multiplicands are too short":
block:
var r = BigInt[200].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDE"
let a = BigInt[29].fromHex"0x12345678"
let b = BigInt[128].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
let expected = BigInt[200].fromHex"fd5bdee65f787f665f787f665f787f65621ca08"
r.prod(a, b)
check: bool(r == expected)
r.prod(b, a)
check: bool(r == expected)
proc mainMulHigh() =
suite "Multi-precision multiplication keeping only high words" & " [" & $WordBitWidth & "-bit mode]":
test "Same size operand into double size result - discard first word":
block:
var r = canary(BigInt[256])
let a = BigInt[128].fromHex"0x12345678FF11FFAA00321321CAFECAFE"
let b = BigInt[128].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
when WordBitWidth == 32:
let expected = BigInt[256].fromHex"fd5bdef43d64113f371ab5d8843beca889c07fd549b84d8a5001a8f"
else:
let expected = BigInt[256].fromHex"fd5bdef43d64113f371ab5d8843beca889c07fd549b84d8"
r.prodhighwords(a, b, 1)
check: bool(r == expected)
r.prodhighwords(b, a, 1)
check: bool(r == expected)
test "Same size operand into double size result - discard first 3 words":
block:
var r = canary(BigInt[256])
let a = BigInt[128].fromHex"0x12345678FF11FFAA00321321CAFECAFE"
let b = BigInt[128].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
when WordBitWidth == 32:
let expected = BigInt[256].fromHex"fd5bdef43d64113f371ab5d8843beca889c07fd"
else:
let expected = BigInt[256].fromHex"fd5bdef43d64113"
r.prodhighwords(a, b, 3)
check: bool(r == expected)
r.prodhighwords(b, a, 3)
check: bool(r == expected)
test "All lower words trigger a carry":
block:
var r = canary(BigInt[256])
let a = BigInt[256].fromHex"0xFFFFF000FFFFF111FFFFFFFAFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
let b = BigInt[256].fromHex"0xFFFFFFFFFFFFF222FFFFFFFBFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
# Full product:
# fffff000ffffe33500ddc21a00cf39720000810900000013fffffffffffffffe
# 00000fff00001ccb000000090000000000000000000000000000000000000001
let expected = BigInt[256].fromHex"0xfffff000ffffe33500ddc21a00cf39720000810900000013fffffffffffffffe"
when WordBitWidth == 32:
const startWord = 8
else:
const startWord = 4
r.prodhighwords(a, b, startWord)
check: bool(r == expected)
r.prodhighwords(b, a, startWord)
check: bool(r == expected)
test "Different size into large result":
block:
var r = canary(BigInt[200])
let a = BigInt[29].fromHex"0x12345678"
let b = BigInt[128].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
when WordBitWidth == 32:
let expected = BigInt[200].fromHex"fd5bdee65f787f665f787f6"
else:
let expected = BigInt[200].fromHex"fd5bdee"
r.prodhighwords(a, b, 2)
check: bool(r == expected)
r.prodhighwords(b, a, 2)
check: bool(r == expected)
test "Destination is properly zero-padded if multiplicands are too short":
block:
var r = BigInt[200].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDE"
let a = BigInt[29].fromHex"0x12345678"
let b = BigInt[128].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
when WordBitWidth == 32:
let expected = BigInt[200].fromHex"fd5bdee65f787f665f787f6"
else:
let expected = BigInt[200].fromHex"fd5bdee"
r.prodhighwords(a, b, 2)
check: bool(r == expected)
r.prodhighwords(b, a, 2)
check: bool(r == expected)
proc mainSquare() =
suite "Multi-precision multiplication" & " [" & $WordBitWidth & "-bit mode]":
test "Squaring is consistent with multiplication (rBits = 2*aBits)":
block:
let a = BigInt[200].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDE"
var rmul, rsqr: BigInt[400]
rmul.prod(a, a)
rsqr.square(a)
check: bool(rmul == rsqr)
test "Squaring is consistent with multiplication (truncated)":
block:
let a = BigInt[200].fromHex"0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDE"
var rmul, rsqr: BigInt[256]
rmul.prod(a, a)
rsqr.square(a)
check: bool(rmul == rsqr)
proc mainModular() =
suite "Modular operations - small modulus" & " [" & $WordBitWidth & "-bit mode]":
# Vectors taken from Stint - https://github.com/status-im/nim-stint
test "100 mod 13":
# Test 1 word and more than 1 word
block:
let a = BigInt[7].fromUint(100'u32)
let m = BigInt[4].fromUint(13'u8)
var r = canary(BigInt[4])
r.reduce(a, m)
let expected = BigInt[4].fromUint(100'u8 mod 13)
doAssert bool(r == expected),
"\n r (low-level repr): " & $r &
"\n expected (ll repr): " & $expected
block: #
let a = BigInt[32].fromUint(100'u32)
let m = BigInt[4].fromUint(13'u8)
var r = canary(BigInt[4])
r.reduce(a, m)
let expected = BigInt[4].fromUint(100'u8 mod 13)
doAssert bool(r == expected),
"\n r (low-level repr): " & $r &
"\n expected (ll repr): " & $expected
block: #
let a = BigInt[64].fromUint(100'u32)
let m = BigInt[4].fromUint(13'u8)
var r = canary(BigInt[4])
r.reduce(a, m)
let expected = BigInt[4].fromUint(100'u8 mod 13)
doAssert bool(r == expected),
"\n r (low-level repr): " & $r &
"\n expected (ll repr): " & $expected
test "2^64 mod 3":
let a = BigInt[65].fromHex("0x10000000000000000")
let m = BigInt[8].fromUint(3'u8)
var r = canary(BigInt[8])
r.reduce(a, m)
let expected = BigInt[8].fromUint(1'u8)
doAssert bool(r == expected),
"\n r (low-level repr): " & $r &
"\n expected (ll repr): " & $expected
test "1234567891234567890 mod 10":
let a = BigInt[64].fromUint(1234567891234567890'u64)
let m = BigInt[8].fromUint(10'u8)
var r = canary(BigInt[8])
r.reduce(a, m)
let expected = BigInt[8].fromUint(0'u8)
doAssert bool(r == expected),
"\n r (low-level repr): " & $r &
"\n expected (ll repr): " & $expected
suite "Modular operations - small modulus - Stint specific failures highlighted by property-based testing" & " [" & $WordBitWidth & "-bit mode]":
# Vectors taken from Stint - https://github.com/status-im/nim-stint
test "Modulo: 65696211516342324 mod 174261910798982":
let u = 65696211516342324'u64
let v = 174261910798982'u64
let a = BigInt[56].fromUint(u)
let m = BigInt[48].fromUint(v)
var r = canary(BigInt[48])
r.reduce(a, m)
let expected = BigInt[48].fromUint(u mod v)
doAssert bool(r == expected),
"\n r (low-level repr): " & $r &
"\n expected (ll repr): " & $expected
test "Modulo: 15080397990160655 mod 600432699691":
let u = 15080397990160655'u64
let v = 600432699691'u64
let a = BigInt[54].fromUint(u)
let m = BigInt[40].fromUint(v)
var r = canary(BigInt[40])
r.reduce(a, m)
let expected = BigInt[40].fromUint(u mod v)
doAssert bool(r == expected),
"\n r (low-level repr): " & $r &
"\n expected (ll repr): " & $expected
proc mainNeg() =
suite "Conditional negation" & " [" & $WordBitWidth & "-bit mode]":
test "Conditional negation":
block:
var a = fromHex(BigInt[128], "0x12345678FF11FFAA00321321CAFECAFE")
var b = fromHex(BigInt[128], "0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF")
let a2 = a
let b2 = b
a.cneg(CtTrue)
b.cneg(CtTrue)
discard a.add(a2)
discard b.add(b2)
check:
bool(a.isZero)
bool(b.isZero)
block:
var a = fromHex(BigInt[128], "0x12345678FF11FFAA00321321CAFECAFE")
var b = fromHex(BigInt[128], "0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF")
let a2 = a
let b2 = b
a.cneg(CtFalse)
b.cneg(CtFalse)
check:
bool(a == a2)
bool(b == b2)
test "Conditional negation with carries":
block:
var a = fromHex(BigInt[128], "0x12345678FF11FFAA00321321FFFFFFFF")
var b = fromHex(BigInt[128], "0xFFFFFFFFFFFFFFFF0000000000000000")
let a2 = a
let b2 = b
a.cneg(CtTrue)
b.cneg(CtTrue)
discard a.add(a2)
discard b.add(b2)
check:
bool(a.isZero)
bool(b.isZero)
block:
var a = fromHex(BigInt[128], "0x123456780000000000321321FFFFFFFF")
var b = fromHex(BigInt[128], "0xFFFFFFFFFFFFFFFF0000000000000000")
let a2 = a
let b2 = b
a.cneg(CtFalse)
b.cneg(CtFalse)
check:
bool(a == a2)
bool(b == b2)
test "Conditional all-zero bit or all-one bit":
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000000")
var b = fromHex(BigInt[128], "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF")
let a2 = a
let b2 = b
a.cneg(CtTrue)
b.cneg(CtTrue)
discard a.add(a2)
discard b.add(b2)
check:
bool(a.isZero)
bool(b.isZero)
block:
var a = fromHex(BigInt[128], "0x00000000000000000000000000000000")
var b = fromHex(BigInt[128], "0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF")
let a2 = a
let b2 = b
a.cneg(CtFalse)
b.cneg(CtFalse)
check:
bool(a == a2)
bool(b == b2)
proc mainCopySwap() =
suite "Copy and Swap" & " [" & $WordBitWidth & "-bit mode]":
test "Conditional copy":
block:
var a = fromHex(BigInt[128], "0x12345678FF11FFAA00321321CAFECAFE")
let b = fromHex(BigInt[128], "0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF")
var expected = a
a.ccopy(b, CtFalse)
check: bool(expected == a)
block:
var a = fromHex(BigInt[128], "0x00000000FFFFFFFFFFFFFFFFFFFFFFFF")
let b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
var expected = b
a.ccopy(b, CtTrue)
check: bool(expected == b)
test "Conditional swap":
block:
var a = fromHex(BigInt[128], "0x12345678FF11FFAA00321321CAFECAFE")
var b = fromHex(BigInt[128], "0xDEADBEEFDEADBEEFDEADBEEFDEADBEEF")
let eA = a
let eB = b
a.cswap(b, CtFalse)
check:
bool(eA == a)
bool(eB == b)
block:
var a = fromHex(BigInt[128], "0x00000000FFFFFFFFFFFFFFFFFFFFFFFF")
var b = fromHex(BigInt[128], "0x00000000000000000000000000000001")
let eA = b
let eB = a
a.cswap(b, CtTrue)
check:
bool(eA == a)
bool(eB == b)
proc mainModularInverse() =
suite "Modular Inverse (with odd modulus)" & " [" & $WordBitWidth & "-bit mode]":
# Note: We don't define multi-precision multiplication
# because who needs it when you have Montgomery?
# ¯\(ツ)/¯
test "42^-1 (mod 2017) = 1969":
block: # small int
let a = BigInt[16].fromUint(42'u16)
let M = BigInt[16].fromUint(2017'u16)
let expected = BigInt[16].fromUint(1969'u16)
var r = canary(BigInt[16])
r.invmod(a, M)
check: bool(r == expected)
block: # huge int
let a = BigInt[381].fromUint(42'u16)
let M = BigInt[381].fromUint(2017'u16)
let expected = BigInt[381].fromUint(1969'u16)
var r = canary(BigInt[381])
r.invmod(a, M)
check: bool(r == expected)
test "271^-1 (mod 383) = 106":
block: # small int
let a = BigInt[16].fromUint(271'u16)
let M = BigInt[16].fromUint(383'u16)
let expected = BigInt[16].fromUint(106'u16)
var r = canary(BigInt[16])
r.invmod(a, M)
check: bool(r == expected)
block: # huge int
let a = BigInt[381].fromUint(271'u16)
let M = BigInt[381].fromUint(383'u16)
let expected = BigInt[381].fromUint(106'u16)
var r = canary(BigInt[381])
r.invmod(a, M)
check: bool(r == expected)
test "BN254_Modulus^-1 (mod BLS12_381)":
let a = BigInt[381].fromHex("0x30644e72e131a029b85045b68181585d97816a916871ca8d3c208c16d87cfd47")
let M = BigInt[381].fromHex("0x1a0111ea397fe69a4b1ba7b6434bacd764774b84f38512bf6730d2a0f6b0f6241eabfffeb153ffffb9feffffffffaaab")
let expected = BigInt[381].fromHex("0x0636759a0f3034fa47174b2c0334902f11e9915b7bd89c6a2b3082b109abbc9837da17201f6d8286fe6203caa1b9d4c8")
var r = canary(BigInt[381])
r.invmod(a, M)
check: bool(r == expected)
test "0^-1 (mod any) = 0 (need for tower of extension fields)":
block:
let a = BigInt[16].fromUint(0'u16)
let M = BigInt[16].fromUint(2017'u16)
let expected = BigInt[16].fromUint(0'u16)
var r = canary(BigInt[16])
r.invmod(a, M)
check: bool(r == expected)
block:
let a = BigInt[381].fromUint(0'u16)
let M = BigInt[381].fromHex("0x1a0111ea397fe69a4b1ba7b6434bacd764774b84f38512bf6730d2a0f6b0f6241eabfffeb153ffffb9feffffffffaaab")
let expected = BigInt[381].fromUint(0'u16)
var r = canary(BigInt[381])
r.invmod(a, M)
check: bool(r == expected)
mainArith()
mainMul()
mainMulHigh()
mainSquare()
mainModular()
mainNeg()
mainCopySwap()
mainModularInverse()