Add native AccountKey type and update account key methods

[turbolent]

Context

Currently account public keys are encoded together with their signature algorithm, hashing algorithm and weight before being passed into Cadence as byte strings. This solution is a relic of the early days of Cadence, before we had support for more sophisticated composite types.

We'd like to move towards a more user-friendly solution, perhaps something like this:

transaction {
  prepare(signer: AuthAccount) {
    let key = AccountKey(
      publicKey: pubKeyBytes, 
      sigAlgo: crypto.ECDSA_P256, 
      hashAlgo: crypto.SHA3_256, 
      weight: 1000,
    )
    signer.keys.add(key)
  }
}

Definition of Done

• Add an AccountKey type:

  struct AccountKey {
        let keyIndex: Int
        let publicKey: Crypto.PublicKey
        let hashAlgorithm: Crypto.HashAlgorithm
        let weight: UFix64
        let isRevoked: Bool
  }
  

• Add an AuthAccount.Keys type with the following functions:

  • Add a AuthAccount.Keys.add function:

    /// Adds a new key with the given weight
    fun add(
        _ publicKey: PublicKey,
        hashAlgorithm: HashAlgorithm,
        weight: UFix64
    ): AccountKey
    

  • Add a AuthAccount.Keys.get function:

    /// Returns the key at the given index, if it exists.
    /// Revoked keys are always returned, but they have `isRevoked` field set to true
    fun get(keyIndex: Int): AccountKey?
    

  • Add a AuthAccount.Keys.revoke function:

    /// Marks the key at the given index revoked, but does not delete it
    fun revoke(keyIndex: Int)
    

• Add an AuthAccount.keys field with type AuthAccount.Keys

• Add an PublicAccount.Keys type with the following functions:

  • Add a PublicAccount.Keys.get function:

    /// Returns the key at the given index, if it exists.
    /// Revoked keys are always returned, but they have `isRevoked` field set to true
    fun get(keyIndex: Int): AccountKey?
    

• Add an PublicAccount.keys field with type PublicAccount.Keys

• Tests

• Documentation

[turbolent]

@SupunS Maybe you could take this on next? Adding this new account key management API would be a great UX improvement. Let me know if you want to talk this through

[SupunS]

@turbolent nice, I will have a look.