How to convert public hex key (String format) to T::AccountId

Question

Can somebody please guide me how to convert public hex key (which is in String format) to T::AccountId?

I have an extrinsic, which is accepting public key 0x307832363438323861303334393166336234666530316165643XXXXXXXXXX in String.

I have to decode it into AccountId. Can somebody please help me to fix this?

Answer 1

// pallet/lib.rs
trait Config: frame_system::Config {
  type AccountIdFromHex: AccountIdFromHex<AccountId = Self::AccountId>;
  ..
}

trait AccountIdFromHex {
  type AccountId;

  fn try_from_hex(hex: Vec<u8>) -> Result<Self::AccountId>;
}

// runtime/lib.rs
impl Config for Runtime {
  type AccountIdFromHex = Converter;
  ..
}

struct Converter;
impl AccountIdFromHex for Converter {
  type AccountId = AccountId32;

  fn from_hex(hex: Vec<u8>) -> Result<Self::AccountId> {
    array_bytes::vec_n_into::<_, _, 32>(hex).map_err(..)
  }
}

Tips:

• String is Vec actually
• AccountId32 impls From<[u8; 32]>, so array_bytes::vec_n_into works
• https://docs.rs/array-bytes/6.2.3/array_bytes/fn.vec_n_into.html

---

If lost the generic ability for your pallet is acceptable. Simply do:

trait Config: frame_system::Config<AccountId = AccountId32> {
  ..
}

#[pallet::call]
fn your_extrinsic(hex: Vec<u8>) -> Result<..> {
  let account_id = array_bytes::vec_n_into::<_, T::AccountId, 32>(hex).map_err(..)?;

  Ok(())
}