On Sat, Jun 28, 2008 at 10:49 PM, <toad at freenetproject.org> wrote:
> Author: toad
> Date: 2008-06-28 14:49:23 +0000 (Sat, 28 Jun 2008)
> New Revision: 20845
>
> Modified:
>
> branches/db4o/freenet/src/freenet/support/io/PaddedEphemerallyEncryptedBucket.java
> Log:
> Don't store the RNG here. Just store a seed created on startup.
>
If we restarted the node twice... The PRNG will be seeded with the
same seed in the two times... -- Is this behavior expected?
IMO, make Node a static field would make the code much simpler in most
code -- we can refer to the node object when we need a prng, database,
etc.... For "many node in a jvm", we can use some ClassLoader
hacks....
> Modified:
> branches/db4o/freenet/src/freenet/support/io/PaddedEphemerallyEncryptedBucket.java
> ===================================================================
> ---
> branches/db4o/freenet/src/freenet/support/io/PaddedEphemerallyEncryptedBucket.java
> 2008-06-28 14:48:55 UTC (rev 20844)
> +++
> branches/db4o/freenet/src/freenet/support/io/PaddedEphemerallyEncryptedBucket.java
> 2008-06-28 14:49:23 UTC (rev 20845)
> @@ -18,6 +18,8 @@
> import freenet.support.api.Bucket;
> import java.util.Random;
>
> +import org.spaceroots.mantissa.random.MersenneTwister;
> +
> import com.db4o.ObjectContainer;
>
> /**
> @@ -29,10 +31,10 @@
>
> private final Bucket bucket;
> private final int minPaddedSize;
> - private final Random randomSource;
> private transient SoftReference /* <Rijndael> */ aesRef;
> /** The decryption key. */
> private final byte[] key;
> + private final byte[] randomSeed;
> private long dataLength;
> private boolean readOnly;
> private int lastOutputStream;
> @@ -49,10 +51,11 @@
> * @throws UnsupportedCipherException
> */
> public PaddedEphemerallyEncryptedBucket(Bucket bucket, int minSize,
> RandomSource strongPRNG, Random weakPRNG) {
> - this.randomSource = weakPRNG;
> this.bucket = bucket;
> if(bucket.size() != 0) throw new
> IllegalArgumentException("Bucket must be empty");
> byte[] tempKey = new byte[32];
> + randomSeed = new byte[32];
> + weakPRNG.nextBytes(randomSeed);
> strongPRNG.nextBytes(tempKey);
> this.key = tempKey;
> this.minPaddedSize = minSize;
> @@ -76,9 +79,10 @@
> if(bucket.size() < knownSize)
> throw new IOException("Bucket "+bucket+" is too small
> on disk - knownSize="+knownSize+" but bucket.size="+bucket.size()+" for
> "+bucket);
> this.dataLength = knownSize;
> - this.randomSource = origRandom;
> this.bucket = bucket;
> if(key.length != 32) throw new IllegalArgumentException("Key
> wrong length: "+key.length);
> + randomSeed = new byte[32];
> + origRandom.nextBytes(randomSeed);
> this.key = key;
> this.minPaddedSize = minSize;
> readOnly = false;
> @@ -86,7 +90,6 @@
> }
>
> public PaddedEphemerallyEncryptedBucket(SimpleFieldSet fs,
> RandomSource origRandom, PersistentFileTracker f) throws
> CannotCreateFromFieldSetException {
> - this.randomSource = origRandom;
> String tmp = fs.get("DataLength");
> if(tmp == null)
> throw new CannotCreateFromFieldSetException("No
> DataLength");
> @@ -116,6 +119,8 @@
> }
> if(dataLength > bucket.size())
> throw new
> CannotCreateFromFieldSetException("Underlying bucket "+bucket+" is too small:
> should be "+dataLength+" actually "+bucket.size());
> + randomSeed = new byte[32];
> + origRandom.nextBytes(randomSeed);
> }
>
> public OutputStream getOutputStream() throws IOException {
> @@ -184,6 +189,7 @@
> Logger.normal(this, "Not padding out
> to length because have been superceded: "+getName());
> return;
> }
> + Random random = new
> MersenneTwister(randomSeed);
>
> synchronized(PaddedEphemerallyEncryptedBucket.this) {
> long finalLength = paddedLength();
> long padding = finalLength -
> dataLength;
> @@ -191,7 +197,7 @@
> long writtenPadding = 0;
> while(writtenPadding < padding) {
> int left = (int)
> Math.min((padding - writtenPadding), (long)buf.length);
> - randomSource.nextBytes(buf);
> + random.nextBytes(buf);
> out.write(buf, 0, left);
> writtenPadding += left;
> }
>
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