Class Blake3
Hashing
Hash mode calculates the same output hash given the same input bytes and can be used as both a message digest and and extensible output function.
Blake3 hasher = Blake3.initHash();
hasher.update("Hello, world!".getBytes(StandardCharsets.UTF_8));
byte[] hash = new byte[32];
hasher.doFinalize(hash);
Keyed Hashing
Keyed hashes take a 32-byte secret key and calculates a message authentication code on some input bytes. These also work as pseudo-random functions (PRFs) with extensible output similar to the extensible hash output. Note that Blake3 keyed hashes have the same performance as plain hashes; the key is used in initialization in place of a standard initialization vector used for plain hashing.
SecureRandom random = SecureRandom.getInstanceStrong();
byte[] key = new byte[32];
random.nextBytes(key);
Blake3 hasher = Blake3.initKeyedHash(key);
hasher.update("Hello, Alice!".getBytes(StandardCharsets.UTF_8));
byte[] mac = new byte[32];
hasher.doFinalize(mac);
Key Derivation
A specific hash mode for deriving session keys and other derived keys in a unique key derivation context identified by some sequence of bytes. These context strings should be unique but do not need to be kept secret. Additional input data is hashed for key material which can be finalized to derive subkeys.
String context = "org.apache.commons.codec.digest.Blake3Example";
byte[] sharedSecret = ...;
byte[] senderId = ...;
byte[] recipientId = ...;
Blake3 kdf = Blake3.initKeyDerivationFunction(context.getBytes(StandardCharsets.UTF_8));
kdf.update(sharedSecret);
kdf.update(senderId);
kdf.update(recipientId);
byte[] txKey = new byte[32];
byte[] rxKey = new byte[32];
kdf.doFinalize(txKey);
kdf.doFinalize(rxKey);
Adapted from the ISC-licensed O(1) Cryptography library by Matt Sicker and ported from the reference public domain implementation by Jack O'Connor.
- Since:
- 1.16
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate static class
private static class
private static class
Represents the state just prior to either producing an eight word chaining value or any number of output bytes when the ROOT flag is set. -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final int
private static final int
private static final int
private static final int
private static final int
private static final int
private static final int
private static final int
private final Blake3.EngineState
private static final int[]
Standard hash key used for plain hashes; same initialization vector as Blake2s.private static final int
private static final int
private static final int
private static final byte[][]
Pre-permuted for all 7 rounds; the second row (2,6,3,...) indicates the base permutation.private static final int
private static final int
private static final int
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionprivate static void
checkBufferArgs
(byte[] buffer, int offset, int length) private static int[]
compress
(int[] chainingValue, int[] blockWords, int blockLength, long counter, int flags) doFinalize
(byte[] out) Finalizes hash output data that depends on the sequence of updated bytes preceding this invocation and any previously finalized bytes.doFinalize
(byte[] out, int offset, int length) Finalizes an arbitrary number of bytes into the provided output array that depends on the sequence of previously updated and finalized bytes.byte[]
doFinalize
(int nrBytes) Squeezes and returns an arbitrary number of bytes dependent on the sequence of previously absorbed and squeezed bytes.private static void
g
(int[] state, int a, int b, int c, int d, int mx, int my) The mixing function, G, which mixes either a column or a diagonal.static byte[]
hash
(byte[] data) Calculates the Blake3 hash of the provided data.static Blake3
initHash()
Constructs a fresh Blake3 hash function.static Blake3
initKeyDerivationFunction
(byte[] kdfContext) Constructs a fresh Blake3 key derivation function using the provided key derivation context byte string.static Blake3
initKeyedHash
(byte[] key) Constructs a fresh Blake3 keyed hash function.static byte[]
keyedHash
(byte[] key, byte[] data) Calculates the Blake3 keyed hash (MAC) of the provided data.private static void
packInt
(int value, byte[] dst, int off, int len) private static int[]
parentChainingValue
(int[] leftChildCV, int[] rightChildCV, int[] key, int flags) private static Blake3.Output
parentOutput
(int[] leftChildCV, int[] rightChildCV, int[] key, int flags) reset()
Resets this instance back to its initial state when it was first constructed.private static void
round
(int[] state, int[] msg, byte[] schedule) private static int
unpackInt
(byte[] buf, int off) private static int[]
unpackInts
(byte[] buf, int nrInts) update
(byte[] in) Updates this hash state using the provided bytes.update
(byte[] in, int offset, int length) Updates this hash state using the provided bytes at an offset.
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Field Details
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BLOCK_LEN
private static final int BLOCK_LEN- See Also:
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BLOCK_INTS
private static final int BLOCK_INTS- See Also:
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KEY_LEN
private static final int KEY_LEN- See Also:
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KEY_INTS
private static final int KEY_INTS- See Also:
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OUT_LEN
private static final int OUT_LEN- See Also:
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CHUNK_LEN
private static final int CHUNK_LEN- See Also:
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CHAINING_VALUE_INTS
private static final int CHAINING_VALUE_INTS- See Also:
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IV
private static final int[] IVStandard hash key used for plain hashes; same initialization vector as Blake2s. -
CHUNK_START
private static final int CHUNK_START- See Also:
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CHUNK_END
private static final int CHUNK_END- See Also:
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PARENT
private static final int PARENT- See Also:
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ROOT
private static final int ROOT- See Also:
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KEYED_HASH
private static final int KEYED_HASH- See Also:
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DERIVE_KEY_CONTEXT
private static final int DERIVE_KEY_CONTEXT- See Also:
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DERIVE_KEY_MATERIAL
private static final int DERIVE_KEY_MATERIAL- See Also:
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MSG_SCHEDULE
private static final byte[][] MSG_SCHEDULEPre-permuted for all 7 rounds; the second row (2,6,3,...) indicates the base permutation. -
engineState
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Constructor Details
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Blake3
private Blake3(int[] key, int flags)
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Method Details
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reset
Resets this instance back to its initial state when it was first constructed.- Returns:
- this
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update
Updates this hash state using the provided bytes.- Parameters:
in
- source array to update data from- Returns:
- this
- Throws:
NullPointerException
- if in is null
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update
Updates this hash state using the provided bytes at an offset.- Parameters:
in
- source array to update data fromoffset
- where in the array to begin reading byteslength
- number of bytes to update- Returns:
- this
- Throws:
NullPointerException
- if in is nullIndexOutOfBoundsException
- if offset or length are negative or if offset + length is greater than the length of the provided array
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doFinalize
Finalizes hash output data that depends on the sequence of updated bytes preceding this invocation and any previously finalized bytes. Note that this can finalize up to 264 bytes per instance.- Parameters:
out
- destination array to finalize bytes into- Returns:
- this
- Throws:
NullPointerException
- if out is null
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doFinalize
Finalizes an arbitrary number of bytes into the provided output array that depends on the sequence of previously updated and finalized bytes. Note that this can finalize up to 264 bytes per instance.- Parameters:
out
- destination array to finalize bytes intooffset
- where in the array to begin writing bytes tolength
- number of bytes to finalize- Returns:
- this
- Throws:
NullPointerException
- if out is nullIndexOutOfBoundsException
- if offset or length are negative or if offset + length is greater than the length of the provided array
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doFinalize
public byte[] doFinalize(int nrBytes) Squeezes and returns an arbitrary number of bytes dependent on the sequence of previously absorbed and squeezed bytes.- Parameters:
nrBytes
- number of bytes to finalize- Returns:
- requested number of finalized bytes
- Throws:
IllegalArgumentException
- if nrBytes is negative
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initHash
Constructs a fresh Blake3 hash function. The instance returned functions as an arbitrary length message digest.- Returns:
- fresh Blake3 instance in hashed mode
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initKeyedHash
Constructs a fresh Blake3 keyed hash function. The instance returned functions as a pseudorandom function (PRF) or as a message authentication code (MAC).- Parameters:
key
- 32-byte secret key- Returns:
- fresh Blake3 instance in keyed mode using the provided key
- Throws:
NullPointerException
- if key is nullIllegalArgumentException
- if key is not 32 bytes
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initKeyDerivationFunction
Constructs a fresh Blake3 key derivation function using the provided key derivation context byte string. The instance returned functions as a key-derivation function which can further absorb additional context data before squeezing derived key data.- Parameters:
kdfContext
- a globally unique key-derivation context byte string to separate key derivation contexts from each other- Returns:
- fresh Blake3 instance in key derivation mode
- Throws:
NullPointerException
- if kdfContext is null
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hash
public static byte[] hash(byte[] data) Calculates the Blake3 hash of the provided data.- Parameters:
data
- source array to absorb data from- Returns:
- 32-byte hash squeezed from the provided data
- Throws:
NullPointerException
- if data is null
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keyedHash
public static byte[] keyedHash(byte[] key, byte[] data) Calculates the Blake3 keyed hash (MAC) of the provided data.- Parameters:
key
- 32-byte secret keydata
- source array to absorb data from- Returns:
- 32-byte mac squeezed from the provided data
- Throws:
NullPointerException
- if key or data are null
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checkBufferArgs
private static void checkBufferArgs(byte[] buffer, int offset, int length) -
packInt
private static void packInt(int value, byte[] dst, int off, int len) -
unpackInt
private static int unpackInt(byte[] buf, int off) -
unpackInts
private static int[] unpackInts(byte[] buf, int nrInts) -
g
private static void g(int[] state, int a, int b, int c, int d, int mx, int my) The mixing function, G, which mixes either a column or a diagonal. -
round
private static void round(int[] state, int[] msg, byte[] schedule) -
compress
private static int[] compress(int[] chainingValue, int[] blockWords, int blockLength, long counter, int flags) -
parentOutput
private static Blake3.Output parentOutput(int[] leftChildCV, int[] rightChildCV, int[] key, int flags) -
parentChainingValue
private static int[] parentChainingValue(int[] leftChildCV, int[] rightChildCV, int[] key, int flags)
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