Package net.i2p.router.transport.crypto
Class DHSessionKeyBuilder
java.lang.Object
net.i2p.router.transport.crypto.DHSessionKeyBuilder
public class DHSessionKeyBuilder extends Object
Generate a new session key through a diffie hellman exchange. This uses the
constants defined in CryptoConstants, which causes the exchange to create a
256 bit session key.
This class precalcs a set of values on its own thread.
Whenever the pool has
less than the minimum, it fills it up again to the max. There is a delay after
each precalculation so that the CPU isn't hosed during startup.
These three parameters are controlled by java environmental variables and
can be adjusted via:
-Dcrypto.dh.precalc.min=40 -Dcrypto.dh.precalc.max=100 -Dcrypto.dh.precalc.delay=60000
(delay is milliseconds)
To disable precalculation, set min to 0
- Since:
- 0.9 moved from net.i2p.crypto
- Author:
- jrandom
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Nested Class Summary
Nested Classes Modifier and Type Class Description static interfaceDHSessionKeyBuilder.Factorystatic classDHSessionKeyBuilder.InvalidPublicParameterExceptionstatic classDHSessionKeyBuilder.PrecalcRunnerTry to keep DH pairs at the ready. -
Constructor Summary
Constructors Constructor Description DHSessionKeyBuilder()Create a new public/private value pair for the DH exchange.DHSessionKeyBuilder(I2PAppContext ctx)Create a new public/private value pair for the DH exchange. -
Method Summary
Modifier and Type Method Description ByteArraygetExtraBytes()Retrieve the extra bytes beyond the session key resulting from the DH exchange.BigIntegergetMyPublicValue()Retrieve the public value used by the local participant in the DH exchange,byte[]getMyPublicValueBytes()Return a 256 byte representation of our public key, with leading 0s if necessary.BigIntegergetPeerPublicValue()byte[]getPeerPublicValueBytes()Return a 256 byte representation of his public key, with leading 0s if necessary.SessionKeygetSessionKey()Retrieve the session key, calculating it if necessary (and if possible).voidsetPeerPublicValue(byte[] val)voidsetPeerPublicValue(BigInteger peerVal)Specify the value given by the peer for use in the session key negotiation
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Constructor Details
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DHSessionKeyBuilder
DHSessionKeyBuilder()Create a new public/private value pair for the DH exchange. Only for internal use and unit tests. Others should get instances from PrecalcRunner.getBuilder() -
DHSessionKeyBuilder
DHSessionKeyBuilder(I2PAppContext ctx)Create a new public/private value pair for the DH exchange. Only for internal use and unit tests. Others should get instances from PrecalcRunner.getBuilder()
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Method Details
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getMyPublicValue
Retrieve the public value used by the local participant in the DH exchange, -
getMyPublicValueBytes
public byte[] getMyPublicValueBytes()Return a 256 byte representation of our public key, with leading 0s if necessary. -
setPeerPublicValue
public void setPeerPublicValue(BigInteger peerVal) throws DHSessionKeyBuilder.InvalidPublicParameterExceptionSpecify the value given by the peer for use in the session key negotiation- Throws:
IllegalStateException- if already setDHSessionKeyBuilder.InvalidPublicParameterException
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setPeerPublicValue
public void setPeerPublicValue(byte[] val) throws DHSessionKeyBuilder.InvalidPublicParameterException- Parameters:
val- 256 bytes- Throws:
DHSessionKeyBuilder.InvalidPublicParameterException
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getPeerPublicValue
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getPeerPublicValueBytes
public byte[] getPeerPublicValueBytes()Return a 256 byte representation of his public key, with leading 0s if necessary. -
getSessionKey
Retrieve the session key, calculating it if necessary (and if possible).- Returns:
- session key exchanged, or null if the exchange is not complete
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getExtraBytes
Retrieve the extra bytes beyond the session key resulting from the DH exchange. If there aren't enough bytes (with all of them being consumed by the 32 byte key), the SHA256 of the key itself is used - but that won't ever happen. Used only by UDP. getData() will be non-null and have at least 32 bytes after call to getSessionKey()- Returns:
- non-null (but rv.getData() may be null)
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