SignerKey (stellar-sdk 2.0.0-beta1 API)

java.lang.Object
- org.stellar.sdk.SignerKey

```
public final class SignerKey
extends java.lang.Object
```
Represents a Stellar signer key used for transaction authorization.
This class supports four types of signers as defined in the Stellar protocol:
- ED25519 - Standard Ed25519 public key signer
- PRE_AUTH_TX - Pre-authorized transaction hash signer
- HASH_X - SHA-256 hash preimage signer
- ED25519_SIGNED_PAYLOAD - Ed25519 signed payload signer (CAP-40)
The Ed25519 Signed Payload Signer (introduced in CAP-40) is particularly useful for multi-party contracts like payment channels, as it allows all parties to share a set of transactions for signing and guarantees that if one transaction is signed and submitted, information is revealed that allows all other transactions in the set to be authorized.
Example usage:
```
 // Create an Ed25519 signer
 SignerKey ed25519Signer = SignerKey.fromEd25519PublicKey("GCEZWKCA5VLDNRLN3RPRJMRZOX3Z6G5CHCGSNFHEYVXM3XOJMDS674JZ");

 // Create a signed payload signer
 byte[] payload = "transaction_hash".getBytes();
 Ed25519SignedPayload signedPayload = new Ed25519SignedPayload(publicKeyBytes, payload);
 SignerKey payloadSigner = SignerKey.fromEd25519SignedPayload(signedPayload);
 
```
See Also:

CAP-40: Ed25519 Signed Payload Signer

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class SignerKey.Ed25519SignedPayload
Represents an Ed25519 signed payload as defined in CAP-40.

Nested Classes
Modifier and Type	Class and Description
`static class`	`SignerKey.Ed25519SignedPayload` Represents an Ed25519 signed payload as defined in CAP-40.

Field Summary

Fields
Modifier and Type Field and Description

static int SIGNED_PAYLOAD_MAX_PAYLOAD_LENGTH
Maximum payload length for Ed25519 signed payload signers.

Fields
Modifier and Type	Field and Description
`static int`	`SIGNED_PAYLOAD_MAX_PAYLOAD_LENGTH` Maximum payload length for Ed25519 signed payload signers.

Constructor Summary

Constructors
Constructor and Description

SignerKey(byte[] key, SignerKeyType type)
Creates a new SignerKey instance.

Constructors
Constructor and Description
`SignerKey(byte[] key, SignerKeyType type)` Creates a new `SignerKey` instance.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`equals(java.lang.Object o)`
`static SignerKey`	`fromEd25519PublicKey(byte[] key)` Creates a SignerKey from an Ed25519 public key.
`static SignerKey`	`fromEd25519PublicKey(java.lang.String key)` Creates a SignerKey from an encoded Ed25519 public key string.
`static SignerKey`	`fromEd25519SignedPayload(byte[] key)` Creates a SignerKey from an Ed25519 signed payload.
`static SignerKey`	`fromEd25519SignedPayload(SignerKey.Ed25519SignedPayload ed25519SignedPayload)` Creates a SignerKey from an Ed25519SignedPayload object.
`static SignerKey`	`fromEd25519SignedPayload(java.lang.String key)` Creates a SignerKey from an encoded Ed25519 signed payload string.
`static SignerKey`	`fromEd25519SignedPayload(java.lang.String ed25519PublicKey, byte[] payload)` Creates a SignerKey from an Ed25519 public key and payload.
`static SignerKey`	`fromEncodedSignerKey(java.lang.String encodedSignerKey)` Creates a SignerKey from an encoded signer key string.
`static SignerKey`	`fromPreAuthTx(byte[] key)` Creates a SignerKey from a pre-authorized transaction hash.
`static SignerKey`	`fromPreAuthTx(java.lang.String key)` Creates a SignerKey from an encoded pre-authorized transaction hash string.
`static SignerKey`	`fromPreAuthTx(Transaction key)` Creates a SignerKey from a pre-authorized transaction.
`static SignerKey`	`fromSha256Hash(byte[] key)` Creates a SignerKey from a SHA-256 hash.
`static SignerKey`	`fromSha256Hash(java.lang.String key)` Creates a SignerKey from an encoded SHA-256 hash string.
`static SignerKey`	`fromXdr(SignerKey signerKey)` Creates a SignerKey from its XDR representation.
`java.lang.String`	`getEncodedSignerKey()` Gets the encoded string representation of this signer key.
`byte[]`	`getKey()` The raw key bytes for this signer.
`SignerKeyType`	`getType()` The type of this signer key.
`int`	`hashCode()`
`SignerKey.Ed25519SignedPayload`	`toEd25519SignedPayload()` Converts this SignerKey to an Ed25519SignedPayload object.
`java.lang.String`	`toString()`
`SignerKey`	`toXdr()` Converts this SignerKey to its XDR representation.

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

- Field Detail
  - SIGNED_PAYLOAD_MAX_PAYLOAD_LENGTH
```
public static final int SIGNED_PAYLOAD_MAX_PAYLOAD_LENGTH
```
    Maximum payload length for Ed25519 signed payload signers. As defined in CAP-40, the payload has a maximum size of 64 bytes.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - SignerKey
```
public SignerKey(byte[] key,
                 SignerKeyType type)
```
    Creates a new SignerKey instance.
    Parameters:
    key - The raw key bytes for this signer. The format depends on the signer type:
    
    ED25519: 32-byte public key
    PRE_AUTH_TX: 32-byte transaction hash
    HASH_X: 32-byte SHA-256 hash
    ED25519_SIGNED_PAYLOAD: Variable length encoded payload with public key
    type - The type of this signer key.
- Method Detail
  - getEncodedSignerKey
```
public java.lang.String getEncodedSignerKey()
```
    Gets the encoded string representation of this signer key.
    
    Returns:
    
    The StrKey-encoded representation of this signer key
    
    Throws:
    
    java.lang.IllegalArgumentException - if the signer key type is unknown
  - fromEncodedSignerKey
```
public static SignerKey fromEncodedSignerKey(java.lang.String encodedSignerKey)
```
    Creates a SignerKey from an encoded signer key string.
    This method automatically detects the signer key type based on the encoded string format and creates the appropriate SignerKey instance.
    
    Parameters:
    
    encodedSignerKey - The StrKey-encoded signer key string
    
    Returns:
    
    A new SignerKey instance
    
    Throws:
    
    java.lang.IllegalArgumentException - if the encoded signer key is invalid
  - fromEd25519PublicKey
```
public static SignerKey fromEd25519PublicKey(byte[] key)
```
    Creates a SignerKey from an Ed25519 public key.
    
    Parameters:
    
    key - The 32-byte Ed25519 public key
    
    Returns:
    
    A new SignerKey instance of type ED25519
  - fromEd25519PublicKey
```
public static SignerKey fromEd25519PublicKey(java.lang.String key)
```
    Creates a SignerKey from an encoded Ed25519 public key string.
    
    Parameters:
    
    key - The StrKey-encoded Ed25519 public key (starts with 'G')
    
    Returns:
    
    A new SignerKey instance of type ED25519
    
    Throws:
    
    java.lang.IllegalArgumentException - if the key is not a valid Ed25519 public key
  - fromPreAuthTx
```
public static SignerKey fromPreAuthTx(byte[] key)
```
    Creates a SignerKey from a pre-authorized transaction hash.
    Pre-authorized transaction signers allow a transaction to be authorized by including the hash of a specific transaction as a signer. This is useful for creating transactions that can only be executed if a specific other transaction is also executed.
    
    Parameters:
    
    key - The 32-byte transaction hash
    
    Returns:
    
    A new SignerKey instance of type PRE_AUTH_TX
  - fromPreAuthTx
```
public static SignerKey fromPreAuthTx(java.lang.String key)
```
    Creates a SignerKey from an encoded pre-authorized transaction hash string.
    
    Parameters:
    
    key - The StrKey-encoded pre-authorized transaction hash (starts with 'T')
    
    Returns:
    
    A new SignerKey instance of type PRE_AUTH_TX
    
    Throws:
    
    java.lang.IllegalArgumentException - if the key is not a valid pre-authorized transaction hash
  - fromPreAuthTx
```
public static SignerKey fromPreAuthTx(Transaction key)
```
    Creates a SignerKey from a pre-authorized transaction.
    
    Parameters:
    
    key - The pre-authorized transaction
    
    Returns:
    
    A new SignerKey instance of type PRE_AUTH_TX
  - fromSha256Hash
```
public static SignerKey fromSha256Hash(byte[] key)
```
    Creates a SignerKey from a SHA-256 hash.
    Hash-X signers allow a transaction to be authorized by revealing the preimage of a specific SHA-256 hash. This is useful for creating hashlocks and other cryptographic puzzles.
    
    Parameters:
    
    key - The 32-byte SHA-256 hash
    
    Returns:
    
    A new SignerKey instance of type HASH_X
  - fromSha256Hash
```
public static SignerKey fromSha256Hash(java.lang.String key)
```
    Creates a SignerKey from an encoded SHA-256 hash string.
    
    Parameters:
    
    key - The StrKey-encoded SHA-256 hash (starts with 'X')
    
    Returns:
    
    A new SignerKey instance of type HASH_X
    
    Throws:
    
    java.lang.IllegalArgumentException - if the key is not a valid SHA-256 hash
  - fromEd25519SignedPayload
```
public static SignerKey fromEd25519SignedPayload(byte[] key)
```
    Creates a SignerKey from an Ed25519 signed payload.
    Ed25519 signed payload signers (CAP-40) allow a transaction to be authorized by providing a signature of a specific payload using an Ed25519 key. This is particularly useful for multi-party contracts where signing one transaction reveals information that allows other transactions to be authorized.
    
    Parameters:
    
    key - The encoded payload containing the Ed25519 public key and payload
    
    Returns:
    
    A new SignerKey instance of type ED25519_SIGNED_PAYLOAD
  - fromEd25519SignedPayload
```
public static SignerKey fromEd25519SignedPayload(java.lang.String ed25519PublicKey,
                                                 byte[] payload)
```
    Creates a SignerKey from an Ed25519 public key and payload.
    This method encodes the Ed25519 public key and payload into the binary format required by the Stellar protocol, including proper padding for the payload.
    
    Parameters:
    
    ed25519PublicKey - The StrKey-encoded Ed25519 public key (starts with 'G')
    
    payload - The payload to be signed (up to 64 bytes)
    
    Returns:
    
    A new SignerKey instance of type ED25519_SIGNED_PAYLOAD
    
    Throws:
    
    java.lang.IllegalArgumentException - if the payload length exceeds the maximum allowed
  - fromEd25519SignedPayload
```
public static SignerKey fromEd25519SignedPayload(SignerKey.Ed25519SignedPayload ed25519SignedPayload)
```
    Creates a SignerKey from an Ed25519SignedPayload object.
    This method encodes the Ed25519 public key and payload into the binary format required by the Stellar protocol, including proper padding for the payload.
    
    Parameters:
    
    ed25519SignedPayload - The Ed25519SignedPayload containing the public key and payload
    
    Returns:
    
    A new SignerKey instance of type ED25519_SIGNED_PAYLOAD
    
    Throws:
    
    UnexpectedException - if an I/O error occurs during encoding
  - fromEd25519SignedPayload
```
public static SignerKey fromEd25519SignedPayload(java.lang.String key)
```
    Creates a SignerKey from an encoded Ed25519 signed payload string.
    
    Parameters:
    
    key - The StrKey-encoded Ed25519 signed payload (starts with 'P')
    
    Returns:
    
    A new SignerKey instance of type ED25519_SIGNED_PAYLOAD
    
    Throws:
    
    java.lang.IllegalArgumentException - if the key is not a valid Ed25519 signed payload
  - toEd25519SignedPayload
```
public SignerKey.Ed25519SignedPayload toEd25519SignedPayload()
```
    Converts this SignerKey to an Ed25519SignedPayload object.
    This method extracts the Ed25519 public key and payload from the encoded binary format used by Ed25519 signed payload signers.
    
    Returns:
    
    An Ed25519SignedPayload object containing the public key and payload
    
    Throws:
    
    java.lang.IllegalArgumentException - if this SignerKey is not of type ED25519_SIGNED_PAYLOAD
  - toXdr
```
public SignerKey toXdr()
```
    Converts this SignerKey to its XDR representation.
    
    Returns:
    
    The XDR representation of this signer key
    
    Throws:
    
    java.lang.IllegalArgumentException - if the signer key type is unknown
  - fromXdr
```
public static SignerKey fromXdr(SignerKey signerKey)
```
    Creates a SignerKey from its XDR representation.
    
    Parameters:
    
    signerKey - The XDR representation of a signer key
    
    Returns:
    
    A new SignerKey instance
    
    Throws:
    
    java.lang.IllegalArgumentException - if the XDR signer key type is unknown
  - getKey
```
public byte[] getKey()
```
    The raw key bytes for this signer. The format depends on the signer type:
    - ED25519: 32-byte public key
    - PRE_AUTH_TX: 32-byte transaction hash
    - HASH_X: 32-byte SHA-256 hash
    - ED25519_SIGNED_PAYLOAD: Variable length encoded payload with public key
  - getType
```
public SignerKeyType getType()
```
    The type of this signer key.
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class SignerKey

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SIGNED_PAYLOAD_MAX_PAYLOAD_LENGTH

Constructor Detail

SignerKey

Method Detail

getEncodedSignerKey

fromEncodedSignerKey

fromEd25519PublicKey

fromEd25519PublicKey

fromPreAuthTx

fromPreAuthTx

fromPreAuthTx

fromSha256Hash

fromSha256Hash

fromEd25519SignedPayload

fromEd25519SignedPayload

fromEd25519SignedPayload

fromEd25519SignedPayload

toEd25519SignedPayload

toXdr

fromXdr

getKey

getType

equals

hashCode

toString