LeaseSet (Javadocs [I2P+ 2.13.0+] - API Version 0.9.70+)

java.lang.Object
- net.i2p.data.DataStructureImpl
- - net.i2p.data.DatabaseEntry
  - - net.i2p.data.LeaseSet

All Implemented Interfaces:
Serializable, DataStructure
Direct Known Subclasses:
LeaseSet2
```
public class LeaseSet
extends DatabaseEntry
```
Defines the set of leases that a destination currently has available for routing messages.
LeaseSet is the fundamental routing structure in I2P, containing:
- Destination: The service endpoint identity
- Encryption Key: Public key for encrypting messages to the destination
- Signing Key: Public key for verifying LeaseSet authenticity
- Leases: List of tunnel endpoints and their validity periods
- Signature: Cryptographic signature proving authenticity
Lease Structure:
- Gateway: Router identity that hosts the tunnel endpoint
- Tunnel ID: Unique identifier for the tunnel on the gateway
- Expiration: Time when the lease becomes invalid
Encryption Support (Legacy):
- ⚠️ SECURITY WARNING: Encryption is poorly designed and probably insecure
- Not Recommended: Use modern alternatives like EncryptedLeaseSet
- Limited Scope: Only encrypts gateway and tunnel ID data
- No Indication: Encrypted leases appear identical to unencrypted ones
- Keyring Required: Routers need desthash and key to decrypt
Encryption Process:
- Client Side: Encryption performed in I2CP client
- Router Side: Local router must decrypt for usage
- Network: Encrypted form transmitted to floodfills
- Access: Decrypted leases only available via getLease(int)
Usage:
- Routing: Primary mechanism for message delivery in I2P
- Load Balancing: Multiple leases provide redundancy and distribution
- Mobility: Leases can be updated as endpoints change
- Discovery: Published to network database for lookup
Security Considerations:
- Signature Verification: Always verify LeaseSet signatures
- Expiration Checking: Ensure leases are still valid
- Encryption Avoidance: Legacy encryption should not be used
- Modern Alternatives: Use LeaseSet2, EncryptedLeaseSet, or MetaLeaseSet
Migration Path:
- LeaseSet2: Enhanced format with better security and features
- EncryptedLeaseSet: Proper encryption with authentication
- MetaLeaseSet: Advanced routing and load balancing
leases and the original leaseset signature. Revocation (zero leases) isn't used anywhere. In addition: - A revoked leaseset has an EarliestLeaseDate of -1, so it will never be stored successfully. - Revocation of an encrypted leaseset will explode. - So having an included signature at all is pointless?
See Also:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`protected byte[]`	`_byteified` Cached serialized byte array for performance.
`protected boolean`	`_checked` Whether decryption has been attempted.
`protected Destination`	`_destination` Destination this LeaseSet is for.
`protected PublicKey`	`_encryptionKey` Encryption public key for the destination.
`protected long`	`_lastExpiration` Latest expiration time among all leases.
`protected List<Lease>`	`_leases` Leases must stay in the order received, or signature verification will fail.
`protected SigningPublicKey`	`_signingKey` Revocation or blinded signing key.
`static int`	`MAX_LEASES` Unlimited before 0.6.3; 6 as of 0.6.3; Increased in version 0.9.

Fields inherited from class net.i2p.data.DatabaseEntry
_signature, KEY_TYPE_ENCRYPTED_LS2, KEY_TYPE_LEASESET, KEY_TYPE_LS2, KEY_TYPE_META_LS2, KEY_TYPE_ROUTERINFO, KEY_TYPE_SERVICE_LIST, KEY_TYPE_SERVICE_RECORD

Constructor Summary
Constructors
Constructor and Description
LeaseSet()
Creates a new leaseset with default values.

Constructors
Constructor and Description
`LeaseSet()` Creates a new leaseset with default values.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addLease(Lease lease)` Adds a lease to this leaseset.
`void`	`encrypt(SessionKey key)` Encrypt the gateway and tunnel ID of each lease, leaving the expire dates unchanged.
`boolean`	`equals(Object object)`
`protected byte[]`	`getBytes()` without sig!
`long`	`getDate()` Same as getEarliestLeaseDate()
`Destination`	`getDestination()` Warning - will be null for LS2 EncryptedLeaseSets if not decrypted
`long`	`getEarliestLeaseDate()` Retrieve the end date of the earliest lease included in this leaseSet.
`PublicKey`	`getEncryptionKey()` Encryption public key.
`PublicKey`	`getEncryptionKey(Set<EncType> supported)` If more than one key, return the first supported one.
`KeysAndCert`	`getKeysAndCert()` Keys and certificate for this lease set.
`long`	`getLatestLeaseDate()` Retrieve the end date of the latest lease included in this leaseSet.
`Lease`	`getLease(int index)` Get the lease at the given index.
`int`	`getLeaseCount()` Gets the number of leases in this leaseset.
`SigningPublicKey`	`getSigningKey()` The revocation key.
`int`	`getType()` Lease set type for the network database.
`int`	`hashCode()` the destination has enough randomness in it to use it by itself for speed
`boolean`	`isCurrent(long fudge)` Determine whether ANY lease is currently valid, at least within a given fudge factor
`void`	`readBytes(InputStream in)` This does NOT validate the signature
`void`	`setDestination(Destination dest)` Sets the destination for this leaseset.
`void`	`setEncryptionKey(PublicKey encryptionKey)` Sets the encryption key for this leaseset.
`void`	`setReceivedBy(Hash localClient)` As of 0.9.65, no longer sets receivedAsReply to true
`void`	`setSigningKey(SigningPublicKey key)` The revocation key.
`int`	`size()` Number of bytes, NOT including signature
`String`	`toString()`
`boolean`	`verifySignature()` Verify that the signature matches the leaseset's destination's signing public key.
`void`	`writeBytes(OutputStream out)` This does NOT validate the signature

Methods inherited from class net.i2p.data.DatabaseEntry
getHash, getReceivedAsPublished, getReceivedAsReply, getReceivedBy, getRoutingKey, getSignature, getSigningPublicKey, isLeaseSet, isLeaseSet, isRouterInfo, setReceivedAsPublished, setReceivedAsReply, setSignature, sign, validateRoutingKey

Methods inherited from class net.i2p.data.DataStructureImpl
calculateHash, fromBase64, fromByteArray, read, toBase64, toByteArray

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - _byteified
```
protected volatile byte[] _byteified
```
    Cached serialized byte array for performance.
  - _checked
```
protected boolean _checked
```
    Whether decryption has been attempted.
  - _destination
```
protected Destination _destination
```
    Destination this LeaseSet is for.
  - _encryptionKey
```
protected PublicKey _encryptionKey
```
    Encryption public key for the destination.
  - _lastExpiration
```
protected long _lastExpiration
```
    Latest expiration time among all leases.
  - _leases
```
protected final List<Lease> _leases
```
    Leases must stay in the order received, or signature verification will fail.
  - _signingKey
```
protected SigningPublicKey _signingKey
```
    Revocation or blinded signing key. For LS1, the revocation key; for LS2, null except the blinded key for encrypted LS2.
  - MAX_LEASES
```
public static final int MAX_LEASES
```
    Unlimited before 0.6.3; 6 as of 0.6.3; Increased in version 0.9. Leasesets larger than 6 should be used with caution, as each lease adds 44 bytes, and routers older than version 0.9 will not be able to connect as they will throw an exception in readBytes(). Also, the churn will be quite rapid, leading to frequent netdb stores and transmission on existing connections. However we increase it now in case some hugely popular eepsite arrives. Strategies elsewhere in the router to efficiently handle large leasesets are TBD.
    See Also:
    Constant Field Values
- Constructor Detail
  - LeaseSet
```
public LeaseSet()
```
    Creates a new leaseset with default values.
- Method Detail
  - addLease
```
public void addLease(Lease lease)
```
    Adds a lease to this leaseset.
    Throws:
    IllegalStateException - if already signed
  - encrypt
```
public void encrypt(SessionKey key)
```
    Encrypt the gateway and tunnel ID of each lease, leaving the expire dates unchanged. This adds an extra dummy lease, because AES data must be padded to 16 bytes. The fact that it is encrypted is not stored anywhere. Must be called after all the leases are in place, but before sign().
  - equals
```
public boolean equals(Object object)
```
    Overrides:
    equals in class Object
  - getBytes
```
protected byte[] getBytes()
```
    without sig!
    Specified by:
    getBytes in class DatabaseEntry
    Returns:
    the raw payload data, or null on error (for example, if this is a RouterInfo, a DataFormatException is thrown instead)
  - getDate
```
public long getDate()
```
    Same as getEarliestLeaseDate()
    Specified by:
    getDate in class DatabaseEntry
    Returns:
    the date
  - getDestination
```
public Destination getDestination()
```
    Warning - will be null for LS2 EncryptedLeaseSets if not decrypted
    Returns:
    Destination or null
  - getEarliestLeaseDate
```
public long getEarliestLeaseDate()
```
    Retrieve the end date of the earliest lease included in this leaseSet. This is the date that should be used in comparisons for leaseSet age - to determine which LeaseSet was published more recently (later earliestLeaseSetDate means it was published later) Warning - do not use this for version comparison for LeaseSet2. Use LeaseSet2.getPublished() instead.
    Returns:
    earliest end date of any lease in the set, or -1 if there are no leases
  - getEncryptionKey
```
public PublicKey getEncryptionKey()
```
    Encryption public key.
    Returns:
    the encryption public key
  - getEncryptionKey
```
public PublicKey getEncryptionKey(Set<EncType> supported)
```
    If more than one key, return the first supported one. If none supported, return null.
    Parameters:
    supported - what return types are allowed
    Returns:
    ElGamal key or null if ElGamal not in supported
  - getKeysAndCert
```
public KeysAndCert getKeysAndCert()
```
    Keys and certificate for this lease set.
    Specified by:
    getKeysAndCert in class DatabaseEntry
    Returns:
    KAC or null
  - getLatestLeaseDate
```
public long getLatestLeaseDate()
```
    Retrieve the end date of the latest lease included in this leaseSet. This is the date used in isCurrent().
    Returns:
    latest end date of any lease in the set, or 0 if there are no leases
  - getLease
```
public Lease getLease(int index)
```
    Get the lease at the given index.
    Parameters:
    index - the lease index
    Returns:
    the lease
  - getLeaseCount
```
public int getLeaseCount()
```
    Gets the number of leases in this leaseset.
    Returns:
    0-16 A LeaseSet with no leases is revoked.
  - getSigningKey
```
public SigningPublicKey getSigningKey()
```
    The revocation key. Undeprecated as of 0.9.38, used for the blinded key in EncryptedLeaseSet.
    Returns:
    the revocation key for LS1, null for LS2 except blinded key for encrypted LS2
  - getType
```
public int getType()
```
    Lease set type for the network database.
    Specified by:
    getType in class DatabaseEntry
    Returns:
    KEY_TYPE_ROUTERINFO or KEY_TYPE_LEASESET or LS2 types
  - hashCode
```
public int hashCode()
```
    the destination has enough randomness in it to use it by itself for speed
    Overrides:
    hashCode in class Object
  - isCurrent
```
public boolean isCurrent(long fudge)
```
    Determine whether ANY lease is currently valid, at least within a given fudge factor
    Parameters:
    fudge - milliseconds fudge factor to allow between the current time
    Returns:
    true if there are current leases, false otherwise
  - readBytes
```
public void readBytes(InputStream in)
               throws DataFormatException,
                      IOException
```
    This does NOT validate the signature
    Parameters:
    in - stream to read from
    Throws:
    IllegalStateException - if called more than once or Destination already set
    DataFormatException - if the data is improperly formatted
    IOException - if there was a problem reading the stream
  - setDestination
```
public void setDestination(Destination dest)
```
    Sets the destination for this leaseset.
    Throws:
    IllegalStateException - if already signed
  - setEncryptionKey
```
public void setEncryptionKey(PublicKey encryptionKey)
```
    Sets the encryption key for this leaseset.
    Throws:
    IllegalStateException - if already signed
  - setReceivedBy
```
public void setReceivedBy(Hash localClient)
```
    As of 0.9.65, no longer sets receivedAsReply to true
    Overrides:
    setReceivedBy in class DatabaseEntry
    Parameters:
    localClient - may be null
  - setSigningKey
```
public void setSigningKey(SigningPublicKey key)
```
    The revocation key. Unused except for encrypted LS2. Must be the same type as the Destination's SigningPublicKey.
    Throws:
    IllegalArgumentException - if different type
  - size
```
public int size()
```
    Number of bytes, NOT including signature
    Returns:
    the size in bytes
  - toString
```
public String toString()
```
    Overrides:
    toString in class Object
  - verifySignature
```
public boolean verifySignature()
```
    Verify that the signature matches the leaseset's destination's signing public key. As of 0.9.47, revocation is not checked.
    Overrides:
    verifySignature in class DatabaseEntry
    Returns:
    true only if the signature matches
  - writeBytes
```
public void writeBytes(OutputStream out)
                throws DataFormatException,
                       IOException
```
    This does NOT validate the signature
    Parameters:
    out - stream to write to
    Throws:
    DataFormatException - if the data was incomplete or not yet ready to be written
    IOException - if there was a problem writing to the stream

Class LeaseSet

Field Summary

Fields inherited from class net.i2p.data.DatabaseEntry

Constructor Summary

Method Summary

Methods inherited from class net.i2p.data.DatabaseEntry

Methods inherited from class net.i2p.data.DataStructureImpl

Methods inherited from class java.lang.Object

Field Detail

_byteified

_checked

_destination

_encryptionKey

_lastExpiration

_leases

_signingKey

MAX_LEASES

Constructor Detail

LeaseSet

Method Detail

addLease

encrypt

equals

getBytes

getDate

getDestination

getEarliestLeaseDate

getEncryptionKey

getEncryptionKey

getKeysAndCert

getLatestLeaseDate

getLease

getLeaseCount

getSigningKey

getType

hashCode

isCurrent

readBytes

setDestination

setEncryptionKey

setReceivedBy

setSigningKey

size

toString

verifySignature

writeBytes