Hashgraph 9.0.0

Version 9.0.0 Hedera API Version 0.28.0

Version 9.0.0 adds support for support for ECDSA(secp256k1) keys and pay-to-alias auto-account creation. Endorsement and Signatory objects now support ECDSA(secp256k1) keys wherever Ed25519 keys are supported. Support for the Ledger property (gossip network identifier) has been added for network info queries producing it. New address types Alias and Moniker have been introduced to represent the alias form of a crypto address and BIP-1014 created contract addresses respectively. These alternative addresses include implicit cast operators to the Address type and can be use as input values identifying crypto accounts and contracts where supported by the HAPI. Please note, the network allows the use of the alias form all HAPI calls, but not all HAPI calls support alias addressing internally, this will support expand over time. 9.0.0 also expands support for pending (scheduled) transactions to include user defined expiry times and support for delayed pending transaction execution. It also includes support for delegation spending allowances, HIP- 336.

For code that provides custom signing services, a new property, MinimumDesiredPrefixSize, is now exposed by the IInvoice interface. This was added to support future interaction requirements where the full public key length may be required when interacting certain smart contract instances. Generally, the .net SDK reduces the prefix to the smallest size possible to reduce network payload and increase privacy. This behavior has always been configurable via the SignaturePrefixTrimLimit property of the IContext.

Breaking Changes:

Breaking changes include the move to .NET 6.0 and removal of the RSA3072 and ECDSA384 key types which will have not been supported by the hedera network and will not be supported in the foreseeable future. There is also one additional behavioral change with the Endorsement and Signatory objects: the convenience constructors that accepted a byte array assumed it was receiving an Ed25519 key type and would throw an error if could not interpret it as such. These constructors now assume the provided bytes are DER encoded key values, and recognizes ECDSA and Ed25519 keys as appropriate. This is a superset of the previous behavior. Additionally, when the type is included in the constructor, a raw key value (non DER encoded) is accepted by the constructors as well, this is an widening of existing behavior, these changes are intended to be backwards compatible with existing code.

Allowances required small potential breaking changes in the TransferParams object to add a flag indicating the spender is an allowed spender. Use of the transfer method taking a TransferParams object is required for transferring via an allowance authorization. The convenience transfer method overloads do not support the allowance/spender flag.