corda / net.corda.core.crypto

Package net.corda.core.crypto



A tree data structure that enables the representation of composite public keys, which are used to represent the signing requirements for multi-signature scenarios such as RAFT notary services. A composite key is a list of leaf keys and their contributing weight, and each leaf can be a conventional single key or a composite key. Keys contribute their weight to the total if they are matched by the signature.

class CompositeKey : PublicKey


Factory for generating composite keys from ASN.1 format key specifications. This is used by CordaSecurityProvider.

class CompositeKeyFactory : KeyFactorySpi


Dedicated class for storing a set of signatures that comprise CompositeKey.

class CompositeSignature : Signature


Custom class for holding signature data. This exists for later extension work to provide a standardised cross-platform serialization format.

data class CompositeSignaturesWithKeys


object CordaObjectIdentifier


class CordaSecurityProvider : Provider


This object controls and provides the available and supported signature schemes for Corda. Any implemented SignatureScheme should be strictly defined here. However, only the schemes returned by {@link #listSupportedSignatureSchemes()} are supported. Note that Corda currently supports the following signature schemes by their code names:

object Crypto


Interface for injecting custom digest implementation bypassing JCA.

interface DigestAlgorithm


The DigestService class is a service that offers the main crypto methods for calculating transaction hashes and building Merkle trees. The default instance is passed by default to instances of classes like TransactionBuilder and as a parameter to MerkleTree.getMerkleTree(...) method. In future the default instance can be parametrized to initialize with the network default hash algorithm or just a more secure algorithm (e.g. SHA3_256). While the SHA2_256 is vulnerable to pre-image attacks, the computeNonce and componentHash methods behaviour is defined by the hashTwiceNonce and hashTwiceComponent; with SHA2_256 they both must be set to true to ensure pre-image attack won't work (and for backward compatibility), but for other algorithms like SHA3_256 that are not affected, they can and should be set to false as hashing twice would not improve security but affect performance.

data class DigestService


A wrapper around a digital signature.

open class DigitalSignature : OpaqueBytes


object DummySecureRandom : SecureRandom


Creation and verification of a Merkle tree for a WireTransaction.

sealed class MerkleTree


object NullKeys


Building and verification of Partial Merkle Tree. Partial Merkle Tree is a minimal tree needed to check that a given set of leaves belongs to a full Merkle Tree.

class PartialMerkleTree


Container for a cryptographically secure hash value. Provides utilities for generating a cryptographic hash using different algorithms (currently only SHA-256 supported).

sealed class SecureHash : OpaqueBytes


A SignableData object is the packet actually signed. It works as a wrapper over transaction id and signature metadata. Note that when multi-transaction signing (signing a block of transactions) is used, the root of the Merkle tree (having transaction IDs as leaves) is actually signed and thus txId refers to this root and not a specific transaction.

data class SignableData


SignatureMeta is required to add extra meta-data to a transaction's signature. It currently supports platformVersion only, but it can be extended to support a universal digital signature model enabling partial signatures and attaching extra information, such as a user's timestamp or other application-specific fields.

data class SignatureMetadata


This class is used to define a digital signature scheme.

data class SignatureScheme


A serialized piece of data and its signature. Enforces signature validity in order to deserialize the data contained within.

open class SignedData<T : Any>


A wrapper over the signature output accompanied by signer's public key and signature metadata. This is similar to DigitalSignature.WithKey, but targeted to DLT transaction (or block of transactions) signatures.

class TransactionSignature : DigitalSignature



class MerkleTreeException : CordaException

Extensions for External Classes





Hash algorithm.

val SecureHash.algorithm: String


val OpaqueBytes.isZero: Boolean



Compute the hash of each serialised component so as to be used as Merkle tree leaf. The resultant output (leaf) is calculated using the SHA256d algorithm, thus SHA256(SHA256(nonce || serializedComponent)), where nonce is computed from computeNonce.

fun componentHash(opaqueBytes: OpaqueBytes, privacySalt: PrivacySalt, componentGroupIndex: Int, internalIndex: Int): SecureHash

Return the SHA256(SHA256(nonce || serializedComponent)).

fun componentHash(nonce: SecureHash, opaqueBytes: OpaqueBytes): SecureHash


Method to compute a nonce based on privacySalt, component group index and component internal index. SHA256d (double SHA256) is used to prevent length extension attacks.

fun computeNonce(privacySalt: PrivacySalt, groupIndex: Int, internalIndex: Int): SHA256


Returns a key pair derived from the given private key entropy. This is useful for unit tests and other cases where you want hard-coded private keys.

fun entropyToKeyPair(entropy: BigInteger): KeyPair


A simple wrapper that will make it easier to swap out the signature algorithm we use in future.

fun generateKeyPair(): KeyPair


Compute the algorithm hash for the contents of the OpaqueBytes.

fun OpaqueBytes.hashAs(algorithm: String): SecureHash


Get an instance of SecureRandom to avoid blocking, due to waiting for additional entropy, when possible. In this version, the NativePRNGNonBlocking is exclusively used on Linux OS to utilize dev/urandom because in high traffic /dev/random may wait for a certain amount of "noise" to be generated on the host machine before returning a result.

fun newSecureRandom(): SecureRandom


Returns a random positive non-zero long generated using a secure RNG. This function sacrifies a bit of entropy in order to avoid potential bugs where the value is used in a context where negative numbers or zero are not expected.

fun random63BitValue(): Long


fun DigestService.randomHash(): SecureHash


Generate a securely random ByteArray of requested number of bytes. Usually used for seeds, nonces and keys.

fun secureRandomBytes(numOfBytes: Int): ByteArray


Serialise the object and return the hash of the serialized bytes. Note that the resulting hash may not be deterministic across platform versions: serialization can produce different values if any of the types being serialized have changed, or if the version of serialization specified by the context changes.

fun <T : Any> serializedHash(x: T): SecureHash


Compute the SHA-256 hash for the contents of the OpaqueBytes.

fun OpaqueBytes.sha256(): SHA256