Prerequisites

# Should be somewhere in $I2P/lib
$CORE=path/to/core.jar
# The destination you want to sign with
$SIGN_WITH=path/to/key.dat
# The destination you want to sign(doesn't have to exist, will be generated if it doesn't exist yet)
$DEST_FILE=path/to/some/other/key.dat

Doing it

java -cp $CORE net.i2p.data.PrivateKeyFile -s $DEST_FILE $SIGN_WITH

Notes

• Make sure that no I2PTunnel-instance is running while doing that(or restart the tunnel after doing this)