diff options
| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2017-06-16 09:53:56 +0700 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2017-06-16 09:53:56 +0700 |
| commit | 76e3e8a975c97f959abd6b45e9b9b94c0087f93e (patch) | |
| tree | ef45e916d12005ed0822c19685457b79f291fff7 /crypto | |
| parent | Improve TLS exception handling (diff) | |
| download | BouncyCastle.NET-ed25519-76e3e8a975c97f959abd6b45e9b9b94c0087f93e.tar.xz | |
Use slightly improved addition chain for sm2p256v1 field sqrt
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs b/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs index 669c73bd2..4f6428f9e 100644 --- a/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs +++ b/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs @@ -143,13 +143,13 @@ namespace Org.BouncyCastle.Math.EC.Custom.GM uint[] x2 = Nat256.Create(); SM2P256V1Field.Square(x1, x2); SM2P256V1Field.Multiply(x2, x1, x2); - uint[] x3 = x2; - SM2P256V1Field.Square(x2, x3); - SM2P256V1Field.Multiply(x3, x1, x3); + uint[] x4 = Nat256.Create(); + SM2P256V1Field.SquareN(x2, 2, x4); + SM2P256V1Field.Multiply(x4, x2, x4); uint[] x6 = Nat256.Create(); - SM2P256V1Field.SquareN(x3, 3, x6); - SM2P256V1Field.Multiply(x6, x3, x6); - uint[] x12 = x3; + SM2P256V1Field.SquareN(x4, 2, x6); + SM2P256V1Field.Multiply(x6, x2, x6); + uint[] x12 = x2; SM2P256V1Field.SquareN(x6, 6, x12); SM2P256V1Field.Multiply(x12, x6, x12); uint[] x24 = Nat256.Create(); @@ -162,25 +162,23 @@ namespace Org.BouncyCastle.Math.EC.Custom.GM SM2P256V1Field.Square(x30, x31); SM2P256V1Field.Multiply(x31, x1, x31); - uint[] t1 = x31; - SM2P256V1Field.Square(x31, t1); + uint[] t1 = x24; + SM2P256V1Field.SquareN(x31, 31, t1); - uint[] x32 = x12; - SM2P256V1Field.Multiply(t1, x1, x32); + uint[] x62 = x30; + SM2P256V1Field.Multiply(t1, x31, x62); SM2P256V1Field.SquareN(t1, 32, t1); - SM2P256V1Field.Multiply(t1, x32, t1); - - uint[] t2 = x24; - SM2P256V1Field.SquareN(t1, 32, t2); - SM2P256V1Field.Multiply(t2, x1, t2); - SM2P256V1Field.SquareN(t2, 32, t2); - SM2P256V1Field.Multiply(t2, t1, t2); - SM2P256V1Field.SquareN(t2, 32, t2); - SM2P256V1Field.Multiply(t2, x32, t2); - SM2P256V1Field.SquareN(t2, 32, t2); - SM2P256V1Field.Multiply(t2, x1, t2); - SM2P256V1Field.SquareN(t2, 62, t1); + SM2P256V1Field.Multiply(t1, x62, t1); + SM2P256V1Field.SquareN(t1, 62, t1); + SM2P256V1Field.Multiply(t1, x62, t1); + SM2P256V1Field.SquareN(t1, 4, t1); + SM2P256V1Field.Multiply(t1, x4, t1); + SM2P256V1Field.SquareN(t1, 32, t1); + SM2P256V1Field.Multiply(t1, x1, t1); + SM2P256V1Field.SquareN(t1, 62, t1); + + uint[] t2 = x4; SM2P256V1Field.Square(t1, t2); return Nat256.Eq(x1, t2) ? new SM2P256V1FieldElement(t1) : null; |