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Diffstat (limited to 'vendor/golang.org/x/crypto/ed25519/ed25519.go')
-rw-r--r--vendor/golang.org/x/crypto/ed25519/ed25519.go13
1 files changed, 10 insertions, 3 deletions
diff --git a/vendor/golang.org/x/crypto/ed25519/ed25519.go b/vendor/golang.org/x/crypto/ed25519/ed25519.go
index 4f26b49b6..a57771a1e 100644
--- a/vendor/golang.org/x/crypto/ed25519/ed25519.go
+++ b/vendor/golang.org/x/crypto/ed25519/ed25519.go
@@ -171,9 +171,16 @@ func Verify(publicKey PublicKey, message, sig []byte) bool {
edwards25519.ScReduce(&hReduced, &digest)
var R edwards25519.ProjectiveGroupElement
- var b [32]byte
- copy(b[:], sig[32:])
- edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &b)
+ var s [32]byte
+ copy(s[:], sig[32:])
+
+ // https://tools.ietf.org/html/rfc8032#section-5.1.7 requires that s be in
+ // the range [0, order) in order to prevent signature malleability.
+ if !edwards25519.ScMinimal(&s) {
+ return false
+ }
+
+ edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &s)
var checkR [32]byte
R.ToBytes(&checkR)