There are a number of ways to look at recovery bits. Either:
:base: In the range{0,1}, which are the outputs of a signer library:ethereum: In the range{27,28}, as defined in the yellow paper:eip155: In the range{35+chain_id*2,35+chain_id*2+1}, as defined in EIP-155
This module provides tools between switching through these choices.
EIP-155 conversion takes an explicit chain_id. Omitting it falls back to
config :cartouche, :chain_id (via Cartouche.Chain.chain_id_value/1). A
signature from a different chain than the one supplied (or configured)
raises Invalid EIP-155 Signature naming both recovery_bit and chain_id.
API Functions
| Function | Arity | Description | Param Kinds |
|---|---|---|---|
recover_base | 2 | Convert a recovery bit from any supported convention into base form. | v: value, chain_id: value |
normalize_signature | 3 | Normalize the recovery bytes of a packed r <> s <> v Ethereum signature. | signature: value, rec_type: value, chain_id: value |
normalize | 3 | Convert a recovery bit into the requested recovery-bit convention. | recovery_bit: value, rec_type: value, chain_id: value |
Summary
Functions
Normalizes a binary-encoded signature to the given requested type,
i.e. :base, :ethereum, or :eip155.
Normalizes a binary-encoded signature to the given requested type,
i.e. :base, :ethereum, or :eip155.
Normalizes a recovery bit to be either 0 or 1.
Types
Functions
@spec normalize(non_neg_integer(), rec_type(), integer() | atom() | nil) :: non_neg_integer() | no_return()
Normalizes a binary-encoded signature to the given requested type,
i.e. :base, :ethereum, or :eip155.
Examples
iex> Cartouche.RecoveryBit.normalize(28, :ethereum)
28
iex> Cartouche.RecoveryBit.normalize(1, :ethereum)
28
iex> Cartouche.RecoveryBit.normalize(27, :base)
0@spec normalize_signature(Cartouche.signature(), rec_type(), integer() | atom() | nil) :: Cartouche.signature() | no_return()
Normalizes a binary-encoded signature to the given requested type,
i.e. :base, :ethereum, or :eip155.
Examples
iex> Cartouche.RecoveryBit.normalize_signature(<<1::256, 2::256, 28>>, :ethereum)
<<1::256, 2::256, 28>>
iex> Cartouche.RecoveryBit.normalize_signature(<<1::256, 2::256, 1>>, :ethereum)
<<1::256, 2::256, 28>>
iex> Cartouche.RecoveryBit.normalize_signature(<<1::256, 2::256, 27>>, :base)
<<1::256, 2::256, 0>>@spec recover_base(non_neg_integer(), integer() | atom() | nil) :: 0 | 1 | no_return()
Normalizes a recovery bit to be either 0 or 1.
EIP-155 values are reduced against chain_id. Omitting it falls back to
config :cartouche, :chain_id. A v from a different chain raises
Invalid EIP-155 Signature naming both recovery_bit and chain_id.
Examples
iex> Cartouche.RecoveryBit.recover_base(0)
0
iex> Cartouche.RecoveryBit.recover_base(1)
1
iex> Cartouche.RecoveryBit.recover_base(27)
0
iex> Cartouche.RecoveryBit.recover_base(28)
1
iex> Cartouche.RecoveryBit.recover_base(2)
** (FunctionClauseError) no function clause matching in Cartouche.RecoveryBit.recover_base/2