diff options
Diffstat (limited to 'crypto/src/math/raw/Nat.cs')
| -rw-r--r-- | crypto/src/math/raw/Nat.cs | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/crypto/src/math/raw/Nat.cs b/crypto/src/math/raw/Nat.cs index 9f2412580..d67de0a5c 100644 --- a/crypto/src/math/raw/Nat.cs +++ b/crypto/src/math/raw/Nat.cs @@ -515,32 +515,42 @@ namespace Org.BouncyCastle.Math.Raw public static uint[] FromBigInteger(int bits, BigInteger x) { + if (bits < 1) + throw new ArgumentException(); if (x.SignValue < 0 || x.BitLength > bits) throw new ArgumentException(); int len = (bits + 31) >> 5; + Debug.Assert(len > 0); uint[] z = Create(len); - int i = 0; - while (x.SignValue != 0) + + // NOTE: Use a fixed number of loop iterations + z[0] = (uint)x.IntValue; + for (int i = 1; i < len; ++i) { - z[i++] = (uint)x.IntValue; x = x.ShiftRight(32); + z[i] = (uint)x.IntValue; } return z; } public static ulong[] FromBigInteger64(int bits, BigInteger x) { + if (bits < 1) + throw new ArgumentException(); if (x.SignValue < 0 || x.BitLength > bits) throw new ArgumentException(); int len = (bits + 63) >> 6; + Debug.Assert(len > 0); ulong[] z = Create64(len); - int i = 0; - while (x.SignValue != 0) + + // NOTE: Use a fixed number of loop iterations + z[0] = (ulong)x.LongValue; + for (int i = 1; i < len; ++i) { - z[i++] = (ulong)x.LongValue; x = x.ShiftRight(64); + z[i] = (ulong)x.LongValue; } return z; } |