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Code Issues Projects Releases Wiki Activity

Added factory methods for segmented connection readers.

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This commit is contained in:
akwizgran
2012-01-17 20:21:26 +00:00
parent 87e1c42bf8
commit dbeb7a207e
21 changed files with 175 additions and 88 deletions
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47
components/net/sf/briar/transport/ConnectionReaderFactoryImpl.java
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@@ -7,8 +7,10 @@ import javax.crypto.Mac;
import net.sf.briar.api.crypto.CryptoComponent;
import net.sf.briar.api.crypto.ErasableKey;
import net.sf.briar.api.plugins.SegmentSource;
import net.sf.briar.api.transport.ConnectionReader;
import net.sf.briar.api.transport.ConnectionReaderFactory;
import net.sf.briar.api.transport.Segment;
import net.sf.briar.util.ByteUtils;
import com.google.inject.Inject;
@@ -24,22 +26,16 @@ class ConnectionReaderFactoryImpl implements ConnectionReaderFactory {
public ConnectionReader createConnectionReader(InputStream in,
byte[] secret, byte[] tag) {
// Validate the tag
Cipher tagCipher = crypto.getTagCipher();
ErasableKey tagKey = crypto.deriveTagKey(secret, true);
long segmentNumber = TagEncoder.decodeTag(tag, tagCipher, tagKey);
tagKey.erase();
if(segmentNumber != 0) throw new IllegalArgumentException();
return createConnectionReader(in, true, secret);
return createConnectionReader(in, secret, tag, true);
}
public ConnectionReader createConnectionReader(InputStream in,
byte[] secret) {
return createConnectionReader(in, false, secret);
return createConnectionReader(in, secret, null, false);
}
private ConnectionReader createConnectionReader(InputStream in,
boolean initiator, byte[] secret) {
byte[] secret, byte[] tag, boolean initiator) {
// Derive the keys and erase the secret
ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
ErasableKey macKey = crypto.deriveMacKey(secret, initiator);
@@ -50,7 +46,38 @@ class ConnectionReaderFactoryImpl implements ConnectionReaderFactory {
Cipher frameCipher = crypto.getFrameCipher();
Mac mac = crypto.getMac();
IncomingEncryptionLayer decrypter = new IncomingEncryptionLayerImpl(in,
tagCipher, frameCipher, tagKey, frameKey, false);
tagCipher, frameCipher, tagKey, frameKey, false, tag);
// No error correction
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);
// Create the reader
return new ConnectionReaderImpl(correcter, mac, macKey);
}
public ConnectionReader createConnectionReader(SegmentSource in,
byte[] secret, Segment buffered) {
return createConnectionReader(in, secret, buffered, true);
}
public ConnectionReader createConnectionReader(SegmentSource in,
byte[] secret) {
return createConnectionReader(in, secret, new SegmentImpl(), false);
}
private ConnectionReader createConnectionReader(SegmentSource in,
byte[] secret, Segment buffered, boolean initiator) {
// Derive the keys and erase the secret
ErasableKey frameKey = crypto.deriveFrameKey(secret, initiator);
ErasableKey macKey = crypto.deriveMacKey(secret, initiator);
ErasableKey tagKey = crypto.deriveTagKey(secret, initiator);
ByteUtils.erase(secret);
// Create the decrypter
Cipher tagCipher = crypto.getTagCipher();
Cipher frameCipher = crypto.getFrameCipher();
Mac mac = crypto.getMac();
IncomingEncryptionLayer decrypter =
new IncomingSegmentedEncryptionLayer(in, tagCipher, frameCipher,
tagKey, frameKey, false, buffered);
// No error correction
IncomingErrorCorrectionLayer correcter =
new NullIncomingErrorCorrectionLayer(decrypter);

2
components/net/sf/briar/transport/IncomingEncryptionLayer.java
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@@ -2,7 +2,7 @@ package net.sf.briar.transport;
import java.io.IOException;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.transport.Segment;
interface IncomingEncryptionLayer {

47
components/net/sf/briar/transport/IncomingEncryptionLayerImpl.java
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@@ -16,7 +16,7 @@ import javax.crypto.spec.IvParameterSpec;
import net.sf.briar.api.FormatException;
import net.sf.briar.api.crypto.ErasableKey;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.transport.Segment;
class IncomingEncryptionLayerImpl implements IncomingEncryptionLayer {
@@ -27,18 +27,20 @@ class IncomingEncryptionLayerImpl implements IncomingEncryptionLayer {
private final byte[] iv, ciphertext;
private final boolean tagEverySegment;
private byte[] bufferedTag;
private boolean firstSegment = true;
private long segmentNumber = 0L;
IncomingEncryptionLayerImpl(InputStream in, Cipher tagCipher,
Cipher frameCipher, ErasableKey tagKey, ErasableKey frameKey,
boolean tagEverySegment) {
boolean tagEverySegment, byte[] bufferedTag) {
this.in = in;
this.tagCipher = tagCipher;
this.frameCipher = frameCipher;
this.tagKey = tagKey;
this.frameKey = frameKey;
this.tagEverySegment = tagEverySegment;
this.bufferedTag = bufferedTag;
blockSize = frameCipher.getBlockSize();
if(blockSize < FRAME_HEADER_LENGTH)
throw new IllegalArgumentException();
@@ -47,29 +49,41 @@ class IncomingEncryptionLayerImpl implements IncomingEncryptionLayer {
}
public boolean readSegment(Segment s) throws IOException {
boolean tag = tagEverySegment && !firstSegment;
boolean expectTag = tagEverySegment || firstSegment;
firstSegment = false;
try {
// If a tag is expected then read, decrypt and validate it
if(tag) {
int offset = 0;
while(offset < TAG_LENGTH) {
int read = in.read(ciphertext, offset, TAG_LENGTH - offset);
if(read == -1) {
if(offset == 0) return false;
throw new EOFException();
if(expectTag) {
// Read the tag if we don't have one buffered
if(bufferedTag == null) {
int offset = 0;
while(offset < TAG_LENGTH) {
int read = in.read(ciphertext, offset,
TAG_LENGTH - offset);
if(read == -1) {
if(offset == 0) return false;
throw new EOFException();
}
offset += read;
}
offset += read;
long seg = TagEncoder.decodeTag(ciphertext, tagCipher,
tagKey);
if(seg == -1) throw new FormatException();
segmentNumber = seg;
} else {
System.out.println("Buffered tag");
long seg = TagEncoder.decodeTag(bufferedTag, tagCipher,
tagKey);
bufferedTag = null;
if(seg == -1) throw new FormatException();
segmentNumber = seg;
}
long seg = TagEncoder.decodeTag(ciphertext, tagCipher, tagKey);
if(seg == -1) throw new FormatException();
segmentNumber = seg;
}
// Read the first block of the frame/segment
int offset = 0;
while(offset < blockSize) {
int read = in.read(ciphertext, offset, blockSize - offset);
if(read == -1) {
if(offset == 0 && !tag && !firstSegment) return false;
if(offset == 0 && !expectTag) return false;
throw new EOFException();
}
offset += read;
@@ -108,7 +122,6 @@ class IncomingEncryptionLayerImpl implements IncomingEncryptionLayer {
}
s.setLength(length);
s.setSegmentNumber(segmentNumber++);
firstSegment = false;
return true;
} catch(IOException e) {
frameKey.erase();

28
components/net/sf/briar/transport/IncomingSegmentedEncryptionLayer.java
View File

@@ -13,8 +13,8 @@ import javax.crypto.spec.IvParameterSpec;
import net.sf.briar.api.FormatException;
import net.sf.briar.api.crypto.ErasableKey;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.plugins.SegmentSource;
import net.sf.briar.api.transport.Segment;
class IncomingSegmentedEncryptionLayer implements IncomingEncryptionLayer {
@@ -23,15 +23,16 @@ class IncomingSegmentedEncryptionLayer implements IncomingEncryptionLayer {
private final ErasableKey tagKey, frameKey;
private final int blockSize;
private final byte[] iv;
private final Segment segment;
private final boolean tagEverySegment;
private final Segment segment;
private Segment bufferedSegment;
private boolean firstSegment = true;
private long segmentNumber = 0L;
IncomingSegmentedEncryptionLayer(SegmentSource in, Cipher tagCipher,
Cipher frameCipher, ErasableKey tagKey, ErasableKey frameKey,
boolean tagEverySegment) {
boolean tagEverySegment, Segment s) {
this.in = in;
this.tagCipher = tagCipher;
this.frameCipher = frameCipher;
@@ -43,20 +44,30 @@ class IncomingSegmentedEncryptionLayer implements IncomingEncryptionLayer {
throw new IllegalArgumentException();
iv = IvEncoder.encodeIv(0L, blockSize);
segment = new SegmentImpl();
bufferedSegment = s;
}
public boolean readSegment(Segment s) throws IOException {
boolean tag = tagEverySegment && !firstSegment;
boolean expectTag = tagEverySegment || firstSegment;
firstSegment = false;
try {
// Read the segment
if(!in.readSegment(segment)) return false;
int offset = tag ? TAG_LENGTH : 0, length = segment.getLength();
// Read the segment, unless we have one buffered
Segment segment;
if(bufferedSegment == null) {
segment = this.segment;
if(!in.readSegment(segment)) return false;
} else {
segment = bufferedSegment;
bufferedSegment = null;
}
int offset = expectTag ? TAG_LENGTH : 0;
int length = segment.getLength();
if(length > MAX_SEGMENT_LENGTH) throw new FormatException();
if(length < offset + FRAME_HEADER_LENGTH + MAC_LENGTH)
throw new FormatException();
byte[] ciphertext = segment.getBuffer();
// If a tag is expected then decrypt and validate it
if(tag) {
if(expectTag) {
long seg = TagEncoder.decodeTag(ciphertext, tagCipher, tagKey);
if(seg == -1) throw new FormatException();
segmentNumber = seg;
@@ -74,7 +85,6 @@ class IncomingSegmentedEncryptionLayer implements IncomingEncryptionLayer {
}
s.setLength(length - offset);
s.setSegmentNumber(segmentNumber++);
firstSegment = false;
return true;
} catch(IOException e) {
frameKey.erase();

2
components/net/sf/briar/transport/NullIncomingErrorCorrectionLayer.java
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@@ -3,7 +3,7 @@ package net.sf.briar.transport;
import java.io.IOException;
import java.util.Collection;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.transport.Segment;
class NullIncomingErrorCorrectionLayer implements IncomingErrorCorrectionLayer {

2
components/net/sf/briar/transport/NullOutgoingErrorCorrectionLayer.java
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@@ -4,7 +4,7 @@ import static net.sf.briar.util.ByteUtils.MAX_32_BIT_UNSIGNED;
import java.io.IOException;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.transport.Segment;
class NullOutgoingErrorCorrectionLayer implements OutgoingErrorCorrectionLayer {

2
components/net/sf/briar/transport/OutgoingEncryptionLayer.java
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@@ -2,7 +2,7 @@ package net.sf.briar.transport;
import java.io.IOException;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.transport.Segment;
interface OutgoingEncryptionLayer {

2
components/net/sf/briar/transport/OutgoingEncryptionLayerImpl.java
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@@ -11,7 +11,7 @@ import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import net.sf.briar.api.crypto.ErasableKey;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.transport.Segment;
class OutgoingEncryptionLayerImpl implements OutgoingEncryptionLayer {

2
components/net/sf/briar/transport/OutgoingSegmentedEncryptionLayer.java
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@@ -9,8 +9,8 @@ import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import net.sf.briar.api.crypto.ErasableKey;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.plugins.SegmentSink;
import net.sf.briar.api.transport.Segment;
class OutgoingSegmentedEncryptionLayer implements OutgoingEncryptionLayer {

2
components/net/sf/briar/transport/SegmentImpl.java
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@@ -1,7 +1,7 @@
package net.sf.briar.transport;
import static net.sf.briar.api.transport.TransportConstants.MAX_SEGMENT_LENGTH;
import net.sf.briar.api.plugins.Segment;
import net.sf.briar.api.transport.Segment;
import net.sf.briar.util.ByteUtils;
class SegmentImpl implements Segment {