diff options
Diffstat (limited to 'crypto/src/bcpg/BcpgInputStream.cs')
| -rw-r--r-- | crypto/src/bcpg/BcpgInputStream.cs | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/crypto/src/bcpg/BcpgInputStream.cs b/crypto/src/bcpg/BcpgInputStream.cs new file mode 100644 index 000000000..3c69fbdf5 --- /dev/null +++ b/crypto/src/bcpg/BcpgInputStream.cs @@ -0,0 +1,355 @@ +using System; +using System.IO; + +using Org.BouncyCastle.Asn1; +using Org.BouncyCastle.Utilities.IO; + +namespace Org.BouncyCastle.Bcpg +{ + /// <remarks>Reader for PGP objects.</remarks> + public class BcpgInputStream + : BaseInputStream + { + private Stream m_in; + private bool next = false; + private int nextB; + + internal static BcpgInputStream Wrap( + Stream inStr) + { + if (inStr is BcpgInputStream) + { + return (BcpgInputStream) inStr; + } + + return new BcpgInputStream(inStr); + } + + private BcpgInputStream( + Stream inputStream) + { + this.m_in = inputStream; + } + + public override int ReadByte() + { + if (next) + { + next = false; + return nextB; + } + + return m_in.ReadByte(); + } + + public override int Read( + byte[] buffer, + int offset, + int count) + { + // Strangely, when count == 0, we should still attempt to read a byte +// if (count == 0) +// return 0; + + if (!next) + return m_in.Read(buffer, offset, count); + + // We have next byte waiting, so return it + + if (nextB < 0) + return 0; // EndOfStream + + if (buffer == null) + throw new ArgumentNullException("buffer"); + + buffer[offset] = (byte) nextB; + next = false; + + return 1; + } + + public byte[] ReadAll() + { + return Streams.ReadAll(this); + } + + public void ReadFully( + byte[] buffer, + int off, + int len) + { + if (Streams.ReadFully(this, buffer, off, len) < len) + throw new EndOfStreamException(); + } + + public void ReadFully( + byte[] buffer) + { + ReadFully(buffer, 0, buffer.Length); + } + + /// <summary>Returns the next packet tag in the stream.</summary> + public PacketTag NextPacketTag() + { + if (!next) + { + try + { + nextB = m_in.ReadByte(); + } + catch (EndOfStreamException) + { + nextB = -1; + } + + next = true; + } + + if (nextB >= 0) + { + if ((nextB & 0x40) != 0) // new + { + return (PacketTag)(nextB & 0x3f); + } + else // old + { + return (PacketTag)((nextB & 0x3f) >> 2); + } + } + + return (PacketTag) nextB; + } + + public Packet ReadPacket() + { + int hdr = this.ReadByte(); + + if (hdr < 0) + { + return null; + } + + if ((hdr & 0x80) == 0) + { + throw new IOException("invalid header encountered"); + } + + bool newPacket = (hdr & 0x40) != 0; + PacketTag tag = 0; + int bodyLen = 0; + bool partial = false; + + if (newPacket) + { + tag = (PacketTag)(hdr & 0x3f); + + int l = this.ReadByte(); + + if (l < 192) + { + bodyLen = l; + } + else if (l <= 223) + { + int b = m_in.ReadByte(); + bodyLen = ((l - 192) << 8) + (b) + 192; + } + else if (l == 255) + { + bodyLen = (m_in.ReadByte() << 24) | (m_in.ReadByte() << 16) + | (m_in.ReadByte() << 8) | m_in.ReadByte(); + } + else + { + partial = true; + bodyLen = 1 << (l & 0x1f); + } + } + else + { + int lengthType = hdr & 0x3; + + tag = (PacketTag)((hdr & 0x3f) >> 2); + + switch (lengthType) + { + case 0: + bodyLen = this.ReadByte(); + break; + case 1: + bodyLen = (this.ReadByte() << 8) | this.ReadByte(); + break; + case 2: + bodyLen = (this.ReadByte() << 24) | (this.ReadByte() << 16) + | (this.ReadByte() << 8) | this.ReadByte(); + break; + case 3: + partial = true; + break; + default: + throw new IOException("unknown length type encountered"); + } + } + + BcpgInputStream objStream; + if (bodyLen == 0 && partial) + { + objStream = this; + } + else + { + PartialInputStream pis = new PartialInputStream(this, partial, bodyLen); + objStream = new BcpgInputStream(pis); + } + + switch (tag) + { + case PacketTag.Reserved: + return new InputStreamPacket(objStream); + case PacketTag.PublicKeyEncryptedSession: + return new PublicKeyEncSessionPacket(objStream); + case PacketTag.Signature: + return new SignaturePacket(objStream); + case PacketTag.SymmetricKeyEncryptedSessionKey: + return new SymmetricKeyEncSessionPacket(objStream); + case PacketTag.OnePassSignature: + return new OnePassSignaturePacket(objStream); + case PacketTag.SecretKey: + return new SecretKeyPacket(objStream); + case PacketTag.PublicKey: + return new PublicKeyPacket(objStream); + case PacketTag.SecretSubkey: + return new SecretSubkeyPacket(objStream); + case PacketTag.CompressedData: + return new CompressedDataPacket(objStream); + case PacketTag.SymmetricKeyEncrypted: + return new SymmetricEncDataPacket(objStream); + case PacketTag.Marker: + return new MarkerPacket(objStream); + case PacketTag.LiteralData: + return new LiteralDataPacket(objStream); + case PacketTag.Trust: + return new TrustPacket(objStream); + case PacketTag.UserId: + return new UserIdPacket(objStream); + case PacketTag.UserAttribute: + return new UserAttributePacket(objStream); + case PacketTag.PublicSubkey: + return new PublicSubkeyPacket(objStream); + case PacketTag.SymmetricEncryptedIntegrityProtected: + return new SymmetricEncIntegrityPacket(objStream); + case PacketTag.ModificationDetectionCode: + return new ModDetectionCodePacket(objStream); + case PacketTag.Experimental1: + case PacketTag.Experimental2: + case PacketTag.Experimental3: + case PacketTag.Experimental4: + return new ExperimentalPacket(tag, objStream); + default: + throw new IOException("unknown packet type encountered: " + tag); + } + } + + public override void Close() + { + m_in.Close(); + base.Close(); + } + + /// <summary> + /// A stream that overlays our input stream, allowing the user to only read a segment of it. + /// NB: dataLength will be negative if the segment length is in the upper range above 2**31. + /// </summary> + private class PartialInputStream + : BaseInputStream + { + private BcpgInputStream m_in; + private bool partial; + private int dataLength; + + internal PartialInputStream( + BcpgInputStream bcpgIn, + bool partial, + int dataLength) + { + this.m_in = bcpgIn; + this.partial = partial; + this.dataLength = dataLength; + } + + public override int ReadByte() + { + do + { + if (dataLength != 0) + { + int ch = m_in.ReadByte(); + if (ch < 0) + { + throw new EndOfStreamException("Premature end of stream in PartialInputStream"); + } + dataLength--; + return ch; + } + } + while (partial && ReadPartialDataLength() >= 0); + + return -1; + } + + public override int Read(byte[] buffer, int offset, int count) + { + do + { + if (dataLength != 0) + { + int readLen = (dataLength > count || dataLength < 0) ? count : dataLength; + int len = m_in.Read(buffer, offset, readLen); + if (len < 1) + { + throw new EndOfStreamException("Premature end of stream in PartialInputStream"); + } + dataLength -= len; + return len; + } + } + while (partial && ReadPartialDataLength() >= 0); + + return 0; + } + + private int ReadPartialDataLength() + { + int l = m_in.ReadByte(); + + if (l < 0) + { + return -1; + } + + partial = false; + + if (l < 192) + { + dataLength = l; + } + else if (l <= 223) + { + dataLength = ((l - 192) << 8) + (m_in.ReadByte()) + 192; + } + else if (l == 255) + { + dataLength = (m_in.ReadByte() << 24) | (m_in.ReadByte() << 16) + | (m_in.ReadByte() << 8) | m_in.ReadByte(); + } + else + { + partial = true; + dataLength = 1 << (l & 0x1f); + } + + return 0; + } + } + } +} |