BigIntegerLittleEndianEncoding (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- net.i2p.crypto.eddsa.math.Encoding
- - net.i2p.crypto.eddsa.math.bigint.BigIntegerLittleEndianEncoding

All Implemented Interfaces:
Serializable
```
public class BigIntegerLittleEndianEncoding
extends Encoding
implements Serializable
```
Little-endian encoding of field elements for EdDSA, backed by BigInteger.
See Also:
Serialized Form

Field Summary
- Fields inherited from class net.i2p.crypto.eddsa.math.Encoding
  f

Constructor Summary
Constructors
Constructor and Description
BigIntegerLittleEndianEncoding()
Constructor

Constructors
Constructor and Description
`BigIntegerLittleEndianEncoding()` Constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`FieldElement`	`decode(byte[] in)` Decode a FieldElement from its $(b-1)$-bit encoding.
`byte[]`	`encode(BigInteger x)` Convert $x$ to little endian.
`byte[]`	`encode(FieldElement x)` Encode a FieldElement in its $(b-1)$-bit encoding.
`boolean`	`isNegative(FieldElement x)` From the Ed25519 paper: $x$ is negative if the $(b-1)$-bit encoding of $x$ is lexicographically larger than the $(b-1)$-bit encoding of $-x$.
`void`	`setField(Field f)` Set the field.
`BigInteger`	`toBigInteger(byte[] in)` Convert in to big endian

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

- Constructor Detail
  - BigIntegerLittleEndianEncoding
```
public BigIntegerLittleEndianEncoding()
```
    Constructor
- Method Detail
  - decode
```
public FieldElement decode(byte[] in)
```
    Decode a FieldElement from its $(b-1)$-bit encoding. The highest bit is masked out.
    Specified by:
    decode in class Encoding
    Parameters:
    in - the $(b-1)$-bit encoding of a FieldElement.
    Returns:
    the FieldElement represented by 'val'.
    Throws:
    IllegalStateException - if field not set
    IllegalArgumentException - if encoding is invalid
  - encode
```
public byte[] encode(BigInteger x)
```
    Convert $x$ to little endian. Constant time.
    Parameters:
    x - the BigInteger value to encode
    Returns:
    array of length $b/8$
    Throws:
    IllegalStateException - if field not set
  - encode
```
public byte[] encode(FieldElement x)
```
    Encode a FieldElement in its $(b-1)$-bit encoding.
    Specified by:
    encode in class Encoding
    Parameters:
    x - the FieldElement to encode
    Returns:
    the $(b-1)$-bit encoding of this FieldElement.
  - isNegative
```
public boolean isNegative(FieldElement x)
```
    From the Ed25519 paper:
    $x$ is negative if the $(b-1)$-bit encoding of $x$ is lexicographically larger than the $(b-1)$-bit encoding of $-x$. If $q$ is an odd prime and the encoding is the little-endian representation of $\{0, 1,\dots, q-1\}$ then the negative elements of $F_q$ are $\{1, 3, 5,\dots, q-2\}$.
    Specified by:
    isNegative in class Encoding
    Parameters:
    x - the FieldElement to check
    Returns:
    true if negative
  - setField
```
public void setField(Field f)
```
    Description copied from class: Encoding
    Set the field.
    Overrides:
    setField in class Encoding
    Parameters:
    f - the field to set
  - toBigInteger
```
public BigInteger toBigInteger(byte[] in)
```
    Convert in to big endian
    Parameters:
    in - the $(b-1)$-bit encoding of a FieldElement.
    Returns:
    the decoded value as a BigInteger

Class BigIntegerLittleEndianEncoding

Field Summary

Fields inherited from class net.i2p.crypto.eddsa.math.Encoding

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

BigIntegerLittleEndianEncoding

Method Detail

decode

encode

encode

isNegative

setField

toBigInteger