diff options
Diffstat (limited to 'crypto/src/asn1/BERBitString.cs')
| -rw-r--r-- | crypto/src/asn1/BERBitString.cs | 179 |
1 files changed, 168 insertions, 11 deletions
diff --git a/crypto/src/asn1/BERBitString.cs b/crypto/src/asn1/BERBitString.cs index a738a75e6..1756ee9c0 100644 --- a/crypto/src/asn1/BERBitString.cs +++ b/crypto/src/asn1/BERBitString.cs @@ -1,4 +1,5 @@ using System; +using System.Diagnostics; using Org.BouncyCastle.Utilities; @@ -7,36 +8,192 @@ namespace Org.BouncyCastle.Asn1 public class BerBitString : DerBitString { - public BerBitString(byte[] data, int padBits) + private const int DefaultSegmentLimit = 1000; + + internal static byte[] FlattenBitStrings(DerBitString[] bitStrings) + { + int count = bitStrings.Length; + switch (count) + { + case 0: + // No bits + return new byte[]{ 0 }; + case 1: + return bitStrings[0].contents; + default: + { + int last = count - 1, totalLength = 0; + for (int i = 0; i < last; ++i) + { + byte[] elementContents = bitStrings[i].contents; + if (elementContents[0] != 0) + throw new ArgumentException("only the last nested bitstring can have padding", "bitStrings"); + + totalLength += elementContents.Length - 1; + } + + // Last one can have padding + byte[] lastElementContents = bitStrings[last].contents; + byte padBits = lastElementContents[0]; + totalLength += lastElementContents.Length; + + byte[] contents = new byte[totalLength]; + contents[0] = padBits; + + int pos = 1; + for (int i = 0; i < count; ++i) + { + byte[] elementContents = bitStrings[i].contents; + int length = elementContents.Length - 1; + Array.Copy(elementContents, 1, contents, pos, length); + pos += length; + } + + Debug.Assert(pos == totalLength); + return contents; + } + } + } + + private readonly int segmentLimit; + private readonly DerBitString[] elements; + + public BerBitString(byte data, int padBits) : base(data, padBits) - { - } + { + this.elements = null; + this.segmentLimit = DefaultSegmentLimit; + } + + public BerBitString(byte[] data) + : this(data, 0) + { + } - public BerBitString(byte[] data) - : base(data) + public BerBitString(byte[] data, int padBits) + : this(data, padBits, DefaultSegmentLimit) { - } + } + + public BerBitString(byte[] data, int padBits, int segmentLimit) + : base(data, padBits) + { + this.elements = null; + this.segmentLimit = segmentLimit; + } public BerBitString(int namedBits) : base(namedBits) { + this.elements = null; + this.segmentLimit = DefaultSegmentLimit; } public BerBitString(Asn1Encodable obj) - : base(obj) + : this(obj.GetDerEncoded(), 0) { - } + } + + public BerBitString(DerBitString[] elements) + : this(elements, DefaultSegmentLimit) + { + } + + public BerBitString(DerBitString[] elements, int segmentLimit) + : base(FlattenBitStrings(elements), false) + { + this.elements = elements; + this.segmentLimit = segmentLimit; + } + + internal BerBitString(byte[] contents, bool check) + : base(contents, check) + { + this.elements = null; + this.segmentLimit = DefaultSegmentLimit; + } + + private bool IsConstructed + { + get { return null != elements || contents.Length > segmentLimit; } + } + + internal override int EncodedLength(bool withID) + { + throw Platform.CreateNotImplementedException("BerBitString.EncodedLength"); + + // TODO This depends on knowing it's not DER + //if (!IsConstructed) + // return EncodedLength(withID, contents.Length); + + //int totalLength = withID ? 4 : 3; + + //if (null != elements) + //{ + // for (int i = 0; i < elements.Length; ++i) + // { + // totalLength += elements[i].EncodedLength(true); + // } + //} + //else if (contents.Length < 2) + //{ + // // No bits + //} + //else + //{ + // int extraSegments = (contents.Length - 2) / (segmentLimit - 1); + // totalLength += extraSegments * EncodedLength(true, segmentLimit); + + // int lastSegmentLength = contents.Length - (extraSegments * (segmentLimit - 1)); + // totalLength += EncodedLength(true, lastSegmentLength); + //} + + //return totalLength; + } internal override void Encode(Asn1OutputStream asn1Out, bool withID) { - if (asn1Out.IsBer) + if (!asn1Out.IsBer) + { + base.Encode(asn1Out, withID); + return; + } + + if (!IsConstructed) { - asn1Out.WriteEncodingDL(withID, Asn1Tags.BitString, (byte)mPadBits, mData, 0, mData.Length); + Encode(asn1Out, withID, contents, 0, contents.Length); + return; + } + + asn1Out.WriteIdentifier(withID, Asn1Tags.Constructed | Asn1Tags.BitString); + asn1Out.WriteByte(0x80); + + if (null != elements) + { + asn1Out.WritePrimitives(elements); + } + else if (contents.Length < 2) + { + // No bits } else { - base.Encode(asn1Out, withID); + byte pad = contents[0]; + int length = contents.Length; + int remaining = length - 1; + int segmentLength = segmentLimit - 1; + + while (remaining > segmentLength) + { + Encode(asn1Out, true, (byte)0, contents, length - remaining, segmentLength); + remaining -= segmentLength; + } + + Encode(asn1Out, true, pad, contents, length - remaining, remaining); } + + asn1Out.WriteByte(0x00); + asn1Out.WriteByte(0x00); } } } |