diff options
Diffstat (limited to 'pg/src/main/java/org/spongycastle/bcpg/BCPGInputStream.java')
| -rw-r--r-- | pg/src/main/java/org/spongycastle/bcpg/BCPGInputStream.java | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/pg/src/main/java/org/spongycastle/bcpg/BCPGInputStream.java b/pg/src/main/java/org/spongycastle/bcpg/BCPGInputStream.java new file mode 100644 index 00000000..aec47c5f --- /dev/null +++ b/pg/src/main/java/org/spongycastle/bcpg/BCPGInputStream.java @@ -0,0 +1,395 @@ +package org.spongycastle.bcpg; + +import java.io.EOFException; +import java.io.IOException; +import java.io.InputStream; + +import org.spongycastle.util.io.Streams; + +/** + * Stream reader for PGP objects + */ +public class BCPGInputStream + extends InputStream implements PacketTags +{ + InputStream in; + boolean next = false; + int nextB; + + public BCPGInputStream( + InputStream in) + { + this.in = in; + } + + public int available() + throws IOException + { + return in.available(); + } + + public int read() + throws IOException + { + if (next) + { + next = false; + + return nextB; + } + else + { + return in.read(); + } + } + + public int read( + byte[] buf, + int off, + int len) + throws IOException + { + if (len == 0) + { + return 0; + } + + if (!next) + { + return in.read(buf, off, len); + } + + // We have next byte waiting, so return it + + if (nextB < 0) + { + return -1; // EOF + } + + buf[off] = (byte)nextB; // May throw NullPointerException... + next = false; // ...so only set this afterwards + + return 1; + } + + public void readFully( + byte[] buf, + int off, + int len) + throws IOException + { + if (Streams.readFully(this, buf, off, len) < len) + { + throw new EOFException(); + } + } + + public byte[] readAll() + throws IOException + { + return Streams.readAll(this); + } + + public void readFully( + byte[] buf) + throws IOException + { + readFully(buf, 0, buf.length); + } + + /** + * Obtains the tag of the next packet in the stream. + * + * @return the {@link PacketTags tag number}. + * + * @throws IOException if an error occurs reading the tag from the stream. + */ + public int nextPacketTag() + throws IOException + { + if (!next) + { + try + { + nextB = in.read(); + } + catch (EOFException e) + { + nextB = -1; + } + } + + next = true; + + if (nextB >= 0) + { + if ((nextB & 0x40) != 0) // new + { + return (nextB & 0x3f); + } + else // old + { + return ((nextB & 0x3f) >> 2); + } + } + + return nextB; + } + + /** + * Reads the next packet from the stream. + * @throws IOException + */ + public Packet readPacket() + throws IOException + { + int hdr = this.read(); + + if (hdr < 0) + { + return null; + } + + if ((hdr & 0x80) == 0) + { + throw new IOException("invalid header encountered"); + } + + boolean newPacket = (hdr & 0x40) != 0; + int tag = 0; + int bodyLen = 0; + boolean partial = false; + + if (newPacket) + { + tag = hdr & 0x3f; + + int l = this.read(); + + if (l < 192) + { + bodyLen = l; + } + else if (l <= 223) + { + int b = in.read(); + + bodyLen = ((l - 192) << 8) + (b) + 192; + } + else if (l == 255) + { + bodyLen = (in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read(); + } + else + { + partial = true; + bodyLen = 1 << (l & 0x1f); + } + } + else + { + int lengthType = hdr & 0x3; + + tag = (hdr & 0x3f) >> 2; + + switch (lengthType) + { + case 0: + bodyLen = this.read(); + break; + case 1: + bodyLen = (this.read() << 8) | this.read(); + break; + case 2: + bodyLen = (this.read() << 24) | (this.read() << 16) | (this.read() << 8) | this.read(); + break; + case 3: + partial = true; + break; + default: + throw new IOException("unknown length type encountered"); + } + } + + BCPGInputStream objStream; + + if (bodyLen == 0 && partial) + { + objStream = this; + } + else + { + objStream = new BCPGInputStream(new PartialInputStream(this, partial, bodyLen)); + } + + switch (tag) + { + case RESERVED: + return new InputStreamPacket(objStream); + case PUBLIC_KEY_ENC_SESSION: + return new PublicKeyEncSessionPacket(objStream); + case SIGNATURE: + return new SignaturePacket(objStream); + case SYMMETRIC_KEY_ENC_SESSION: + return new SymmetricKeyEncSessionPacket(objStream); + case ONE_PASS_SIGNATURE: + return new OnePassSignaturePacket(objStream); + case SECRET_KEY: + return new SecretKeyPacket(objStream); + case PUBLIC_KEY: + return new PublicKeyPacket(objStream); + case SECRET_SUBKEY: + return new SecretSubkeyPacket(objStream); + case COMPRESSED_DATA: + return new CompressedDataPacket(objStream); + case SYMMETRIC_KEY_ENC: + return new SymmetricEncDataPacket(objStream); + case MARKER: + return new MarkerPacket(objStream); + case LITERAL_DATA: + return new LiteralDataPacket(objStream); + case TRUST: + return new TrustPacket(objStream); + case USER_ID: + return new UserIDPacket(objStream); + case USER_ATTRIBUTE: + return new UserAttributePacket(objStream); + case PUBLIC_SUBKEY: + return new PublicSubkeyPacket(objStream); + case SYM_ENC_INTEGRITY_PRO: + return new SymmetricEncIntegrityPacket(objStream); + case MOD_DETECTION_CODE: + return new ModDetectionCodePacket(objStream); + case EXPERIMENTAL_1: + case EXPERIMENTAL_2: + case EXPERIMENTAL_3: + case EXPERIMENTAL_4: + return new ExperimentalPacket(tag, objStream); + default: + throw new IOException("unknown packet type encountered: " + tag); + } + } + + public void close() + throws IOException + { + in.close(); + } + + /** + * 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. + */ + private static class PartialInputStream + extends InputStream + { + private BCPGInputStream in; + private boolean partial; + private int dataLength; + + PartialInputStream( + BCPGInputStream in, + boolean partial, + int dataLength) + { + this.in = in; + this.partial = partial; + this.dataLength = dataLength; + } + + public int available() + throws IOException + { + int avail = in.available(); + + if (avail <= dataLength || dataLength < 0) + { + return avail; + } + else + { + if (partial && dataLength == 0) + { + return 1; + } + return dataLength; + } + } + + private int loadDataLength() + throws IOException + { + int l = in.read(); + + if (l < 0) + { + return -1; + } + + partial = false; + if (l < 192) + { + dataLength = l; + } + else if (l <= 223) + { + dataLength = ((l - 192) << 8) + (in.read()) + 192; + } + else if (l == 255) + { + dataLength = (in.read() << 24) | (in.read() << 16) | (in.read() << 8) | in.read(); + } + else + { + partial = true; + dataLength = 1 << (l & 0x1f); + } + + return dataLength; + } + + public int read(byte[] buf, int offset, int len) + throws IOException + { + do + { + if (dataLength != 0) + { + int readLen = (dataLength > len || dataLength < 0) ? len : dataLength; + readLen = in.read(buf, offset, readLen); + if (readLen < 0) + { + throw new EOFException("premature end of stream in PartialInputStream"); + } + dataLength -= readLen; + return readLen; + } + } + while (partial && loadDataLength() >= 0); + + return -1; + } + + public int read() + throws IOException + { + do + { + if (dataLength != 0) + { + int ch = in.read(); + if (ch < 0) + { + throw new EOFException("premature end of stream in PartialInputStream"); + } + dataLength--; + return ch; + } + } + while (partial && loadDataLength() >= 0); + + return -1; + } + } +} |