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author | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-02-27 19:55:53 +0700 |
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committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-02-27 19:55:53 +0700 |
commit | dffd5540d611f199901fe3a5ee64e7553963b7c1 (patch) | |
tree | ccf79f5a90b0f145ae2a28ba419b4d1e5fe1b6b2 /crypto/src/math/ec/Mod.cs | |
parent | Equality/hashcode should ignore "excess" words (diff) | |
download | BouncyCastle.NET-ed25519-dffd5540d611f199901fe3a5ee64e7553963b7c1.tar.xz |
Optimized Sqrt() for custom secp224r1
Diffstat (limited to 'crypto/src/math/ec/Mod.cs')
-rw-r--r-- | crypto/src/math/ec/Mod.cs | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/crypto/src/math/ec/Mod.cs b/crypto/src/math/ec/Mod.cs index a05ff77aa..37958e57e 100644 --- a/crypto/src/math/ec/Mod.cs +++ b/crypto/src/math/ec/Mod.cs @@ -1,6 +1,7 @@ using System; using System.Diagnostics; +using Org.BouncyCastle.Crypto.Utilities; using Org.BouncyCastle.Utilities; namespace Org.BouncyCastle.Math.EC @@ -73,6 +74,31 @@ namespace Org.BouncyCastle.Math.EC } } + public static uint[] Random(uint[] p) + { + int len = p.Length; + Random rand = new Random(); + uint[] s = Nat.Create(len); + + uint m = p[len - 1]; + m |= m >> 1; + m |= m >> 2; + m |= m >> 4; + m |= m >> 8; + m |= m >> 16; + + do + { + byte[] bytes = new byte[len << 2]; + rand.NextBytes(bytes); + Pack.BE_To_UInt32(bytes, 0, s); + s[len - 1] &= m; + } + while (Nat.Gte(len, s, p)); + + return s; + } + public static void Subtract(uint[] p, uint[] x, uint[] y, uint[] z) { int len = p.Length; |