Avoid overflow in newhope.go.
Depending on bittedness of the runner, uint16 * uint16 can overflow an int.
There's other computations that can overflow a uint32 as well, so I just made
everything uint64 to avoid thinking about it too much.
Change-Id: Ia3c976987f39f78285c865a2d7688600d73c2514
Reviewed-on: https://boringssl-review.googlesource.com/8193
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/newhope/newhope.go b/ssl/test/runner/newhope/newhope.go
index 36c2c85..8f7a530 100644
--- a/ssl/test/runner/newhope/newhope.go
+++ b/ssl/test/runner/newhope/newhope.go
@@ -153,24 +153,24 @@
// details of how this works.
func ntt(in *Poly, omega, preScaleBase, postScaleBase, postScale uint16) *Poly {
out := new(Poly)
- omega_to_the_i := 1
+ omega_to_the_i := uint64(1)
for i := range out {
- omegaToTheIJ := 1
- preScale := int(1)
- sum := 0
+ omegaToTheIJ := uint64(1)
+ preScale := uint64(1)
+ sum := uint64(0)
for j := range in {
- t := (int(in[j]) * preScale) % q
+ t := (uint64(in[j]) * preScale) % q
sum += (t * omegaToTheIJ) % q
omegaToTheIJ = (omegaToTheIJ * omega_to_the_i) % q
- preScale = (int(preScaleBase) * preScale) % q
+ preScale = (uint64(preScaleBase) * preScale) % q
}
- out[i] = uint16((sum * int(postScale)) % q)
+ out[i] = uint16((sum * uint64(postScale)) % q)
- omega_to_the_i = (omega_to_the_i * int(omega)) % q
- postScale = uint16((int(postScale) * int(postScaleBase)) % q)
+ omega_to_the_i = (omega_to_the_i * uint64(omega)) % q
+ postScale = uint16((uint64(postScale) * uint64(postScaleBase)) % q)
}
return out
@@ -255,7 +255,7 @@
bFreq := new(Poly)
for i := range bFreq {
- bFreq[i] = uint16((int(sFreq[i])*int(aFreq[i]) + int(eFreq[i])) % q)
+ bFreq[i] = uint16((uint64(sFreq[i])*uint64(aFreq[i]) + uint64(eFreq[i])) % q)
}
offerMsg = encodePoly(bFreq)
@@ -279,18 +279,18 @@
uFreq := new(Poly)
for i := range uFreq {
- uFreq[i] = uint16((int(sPrimeFreq[i])*int(aFreq[i]) + int(ePrimeFreq[i])) % q)
+ uFreq[i] = uint16((uint64(sPrimeFreq[i])*uint64(aFreq[i]) + uint64(ePrimeFreq[i])) % q)
}
vFreq := new(Poly)
for i := range vFreq {
- vFreq[i] = uint16((int(sPrimeFreq[i]) * int(bFreq[i])) % q)
+ vFreq[i] = uint16((uint64(sPrimeFreq[i]) * uint64(bFreq[i])) % q)
}
v := inverseNTT(vFreq)
ePrimePrime := sampleNoise(rand)
for i := range v {
- v[i] = uint16((int(v[i]) + int(ePrimePrime[i])) % q)
+ v[i] = uint16((uint64(v[i]) + uint64(ePrimePrime[i])) % q)
}
rec := helprec(rand, v)
@@ -311,7 +311,7 @@
rec := decodeRec(acceptMsg[encodedPolyLen:])
for i, u := range uFreq {
- uFreq[i] = uint16((int(u) * int(sk[i])) % q)
+ uFreq[i] = uint16((uint64(u) * uint64(sk[i])) % q)
}
u := inverseNTT(uFreq)
