summary refs log tree commit diff
path: root/crypto/src/crypto/prng/X931SecureRandom.cs
blob: d40134851d8097d9dc10f633baab11fe7cba65bf (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
using System;

using Org.BouncyCastle.Security;

namespace Org.BouncyCastle.Crypto.Prng
{
    public class X931SecureRandom
        :   SecureRandom
    {
        private readonly bool           mPredictionResistant;
        private readonly SecureRandom   mRandomSource;
        private readonly X931Rng        mDrbg;

        internal X931SecureRandom(SecureRandom randomSource, X931Rng drbg, bool predictionResistant)
            : base(null)
        {
            this.mRandomSource = randomSource;
            this.mDrbg = drbg;
            this.mPredictionResistant = predictionResistant;
        }

        public override void SetSeed(byte[] seed)
        {
            lock (this)
            {
                if (mRandomSource != null)
                {
                    this.mRandomSource.SetSeed(seed);
                }
            }
        }

#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
        public override void SetSeed(Span<byte> seed)
        {
            lock (this)
            {
                if (mRandomSource != null)
                {
                    this.mRandomSource.SetSeed(seed);
                }
            }
        }
#endif

        public override void SetSeed(long seed)
        {
            lock (this)
            {
                // this will happen when SecureRandom() is created
                if (mRandomSource != null)
                {
                    this.mRandomSource.SetSeed(seed);
                }
            }
        }

        public override void NextBytes(byte[] bytes)
        {
            NextBytes(bytes, 0, bytes.Length);
        }

        public override void NextBytes(byte[] buf, int off, int len)
        {
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
            NextBytes(buf.AsSpan(off, len));
#else
            lock (this)
            {
                // check if a reseed is required...
                if (mDrbg.Generate(buf, off, len, mPredictionResistant) < 0)
                {
                    mDrbg.Reseed();
                    mDrbg.Generate(buf, off, len, mPredictionResistant);
                }
            }
#endif
        }

#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
        public override void NextBytes(Span<byte> buffer)
        {
            lock (this)
            {
                // check if a reseed is required...
                if (mDrbg.Generate(buffer, mPredictionResistant) < 0)
                {
                    mDrbg.Reseed();
                    mDrbg.Generate(buffer, mPredictionResistant);
                }
            }
        }
#endif

        public override byte[] GenerateSeed(int numBytes)
        {
            return EntropyUtilities.GenerateSeed(mDrbg.EntropySource, numBytes);
        }
    }
}