Class Bech32

java.lang.Object

com.codename1.crypto.encoding.Bech32

public final class Bech32
extends Object

Bech32 (BIP-173) and Bech32m (BIP-350) encoding, bit regrouping and the SegWit address helpers built on them.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	Bech32.Decoded	The result of decode(String).
static final class	Bech32.SegwitAddress	The result of decodeSegwitAddress(String, String).

Field Summary

Fields

Modifier and Type	Field	Description
static final int	BECH32	Checksum variant constant for original Bech32 (BIP-173).
static final int	BECH32M	Checksum variant constant for Bech32m (BIP-350).

Method Summary

Modifier and Type	Method	Description
static byte[]	convertBits(byte[] data, int fromBits, int toBits, boolean pad)	Regroups bits, for example 8-bit bytes to 5-bit values and back.
static Bech32.Decoded	decode(String str)	Decodes and validates a Bech32 or Bech32m string.
static Bech32.SegwitAddress	decodeSegwitAddress(String hrp, String addr)	Decodes and validates a SegWit address.
static String	encode(String hrp, byte[] data, int variant)	Encodes an HRP and 5-bit data into a Bech32 or Bech32m string.
static String	encodeSegwitAddress(String hrp, int witnessVersion, byte[] program)	Encodes a SegWit address, using Bech32 for witness version 0 and Bech32m otherwise.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

BECH32

public static final int BECH32

Checksum variant constant for original Bech32 (BIP-173).

See Also:

• Constant Field Values

BECH32M

public static final int BECH32M

Checksum variant constant for Bech32m (BIP-350).

See Also:

• Constant Field Values

Method Details

encode

public static String encode(String hrp,
 byte[] data,
 int variant)

Encodes an HRP and 5-bit data into a Bech32 or Bech32m string.

Parameters

• hrp: the human readable part, 1 to 83 printable ASCII characters (33 to 126); uppercase is folded
• data: values in the range 0 to 31
• variant: BECH32 or BECH32M

Returns

the lowercase encoded string

Throws

• IllegalArgumentException: for an invalid HRP, data value, variant or total length over 90

decode

public static Bech32.Decoded decode(String str)

Decodes and validates a Bech32 or Bech32m string.

Parameters

• str: the encoded text

Returns

the HRP, data and checksum variant

Throws

• IllegalArgumentException: for any violation of the BIP-173/BIP-350 rules

convertBits

public static byte[] convertBits(byte[] data,
 int fromBits,
 int toBits,
 boolean pad)

Regroups bits, for example 8-bit bytes to 5-bit values and back.

Parameters

• data: input values, each fitting in fromBits bits
• fromBits: input group size, 1 to 8
• toBits: output group size, 1 to 8
• pad: whether leftover bits are zero padded (encoding) or must be zero and shorter than a group (decoding)

Returns

the regrouped values

Throws

• IllegalArgumentException: for an out-of-range value or invalid padding

encodeSegwitAddress

public static String encodeSegwitAddress(String hrp,
 int witnessVersion,
 byte[] program)

Encodes a SegWit address, using Bech32 for witness version 0 and Bech32m otherwise.

Parameters

• hrp: the network prefix such as bc or tb
• witnessVersion: 0 to 16
• program: the witness program, 2 to 40 bytes (20 or 32 for version 0)

Returns

the address

Throws

• IllegalArgumentException: if the version or program length is invalid

decodeSegwitAddress

public static Bech32.SegwitAddress decodeSegwitAddress(String hrp,
 String addr)

Decodes and validates a SegWit address.

Parameters

• hrp: the expected network prefix, compared without regard to case
• addr: the address

Returns

the witness version and program

Throws

• IllegalArgumentException: if the address is invalid or has another HRP