aboutsummaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/crypto/ed25519/internal
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/golang.org/x/crypto/ed25519/internal')
-rw-r--r--vendor/golang.org/x/crypto/ed25519/internal/edwards25519/edwards25519.go22
1 files changed, 22 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/ed25519/internal/edwards25519/edwards25519.go b/vendor/golang.org/x/crypto/ed25519/internal/edwards25519/edwards25519.go
index 5f8b994..fd03c25 100644
--- a/vendor/golang.org/x/crypto/ed25519/internal/edwards25519/edwards25519.go
+++ b/vendor/golang.org/x/crypto/ed25519/internal/edwards25519/edwards25519.go
@@ -4,6 +4,8 @@
package edwards25519
+import "encoding/binary"
+
// This code is a port of the public domain, “ref10” implementation of ed25519
// from SUPERCOP.
@@ -1769,3 +1771,23 @@ func ScReduce(out *[32]byte, s *[64]byte) {
out[30] = byte(s11 >> 9)
out[31] = byte(s11 >> 17)
}
+
+// order is the order of Curve25519 in little-endian form.
+var order = [4]uint64{0x5812631a5cf5d3ed, 0x14def9dea2f79cd6, 0, 0x1000000000000000}
+
+// ScMinimal returns true if the given scalar is less than the order of the
+// curve.
+func ScMinimal(scalar *[32]byte) bool {
+ for i := 3; ; i-- {
+ v := binary.LittleEndian.Uint64(scalar[i*8:])
+ if v > order[i] {
+ return false
+ } else if v < order[i] {
+ break
+ } else if i == 0 {
+ return false
+ }
+ }
+
+ return true
+}