Module: Klay::Signature

Extended by:
Signature
Included in:
Signature
Defined in:
lib/klay/signature.rb

Overview

Defines handy tools for verifying and recovering signatures.

Defined Under Namespace

Classes: SignatureError

Constant Summary collapse

EIP191_PREFIX_BYTE =

EIP-191 prefix byte 0x19

"\x19".freeze
EIP712_VERSION_BYTE =

EIP-712 version byte 0x01

"\x01".freeze

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.dissect(signature) ⇒ String

Dissects a signature blob of 65+ bytes into its r, s, and v values.

Parameters:

  • signature (String) —

    a concatenated Secp256k1 signature string.

Returns:

  • (String, String, String) —

    the r, s, and v values.

Raises:



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# File 'lib/klay/signature.rb', line 50

def dissect(signature)
  signature = Util.bin_to_hex signature unless Util.is_hex? signature
  signature = Util.remove_hex_prefix signature
  if signature.size != 130
    raise SignatureError, "Unknown signature length #{signature.size}!"
  end
  r = signature[0...64]
  s = signature[64...128]
  v = signature[128..]
  return r, s, v
end

.personal_recover(message, signature, chain_id = Chain::CYPRESS) ⇒ String

Recovers a public key from a prefixed, personal message and a signature on a given chain. (EIP-191) Ref: https://eips.ethereum.org/EIPS/eip-191

Parameters:

  • message (String) —

    the message string.

  • signature (String) —

    the hex string containing the signature.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID the signature should be recovered from.

Returns:

  • (String) —

    a hexa-decimal, uncompressed public key.



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# File 'lib/klay/signature.rb', line 89

def personal_recover(message, signature, chain_id = Chain::CYPRESS)
  prefixed_message = prefix_message message
  hashed_message = Util.keccak256 prefixed_message
  recover hashed_message, signature, chain_id
end

.prefix_message(message) ⇒ String

Prefix message as per EIP-191 with 0x19 to ensure the data is not valid RLP and thus not mistaken for a transaction. EIP-191 Version byte: 0x45 (E) Ref: https://eips.ethereum.org/EIPS/eip-191

Parameters:

  • message (String) —

    the message string to be prefixed.

Returns:

  • (String) —

    an EIP-191 prefixed string.



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# File 'lib/klay/signature.rb', line 40

def prefix_message(message)
  "\u0019Klaytn Signed Message:\n#{message.size}#{message}"
end

.recover(blob, signature, chain_id = Chain::CYPRESS) ⇒ String

Recovers a signature from arbitrary data without validation on a given chain.

Parameters:

  • blob (String) —

    that arbitrary data to be recovered.

  • signature (String) —

    the hex string containing the signature.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID the signature should be recovered from.

Returns:

  • (String) —

    a hexa-decimal, uncompressed public key.

Raises:



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# File 'lib/klay/signature.rb', line 69

def recover(blob, signature, chain_id = Chain::CYPRESS)
  context = Secp256k1::Context.new
  r, s, v = dissect signature
  v = v.to_i(16)
  # raise SignatureError, "Invalid signature v byte #{v} for chain ID #{chain_id}!" if v != 130
  recovery_id = Chain.to_recovery_id v, chain_id
  signature_rs = Util.hex_to_bin "#{r}#{s}"
  recoverable_signature = context.recoverable_signature_from_compact signature_rs, recovery_id
  public_key = recoverable_signature.recover_public_key blob
  Util.bin_to_hex public_key.uncompressed
end

.recover_typed_data(typed_data, signature, chain_id = Chain::CYPRESS) ⇒ String

Recovers a public key from a typed data structure and a signature on a given chain. (EIP-712) Ref: https://eips.ethereum.org/EIPS/eip-712

Parameters:

  • typed_data (Array) —

    all the data in the typed data structure to be recovered.

  • signature (String) —

    the hex string containing the signature.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID the signature should be recovered from.

Returns:

  • (String) —

    a hexa-decimal, uncompressed public key.



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# File 'lib/klay/signature.rb', line 103

def recover_typed_data(typed_data, signature, chain_id = Chain::CYPRESS)
  hash_to_sign = Eip712.hash typed_data
  recover hash_to_sign, signature, chain_id
end

.verify(blob, signature, public_key, chain_id = Chain::CYPRESS) ⇒ Boolean

Verifies a signature for a given public key or address.

Parameters:

  • blob (String) —

    that arbitrary data to be verified.

  • signature (String) —

    the hex string containing the signature.

  • public_key (String) —

    either a public key or an Klaytn address.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID used to sign.

Returns:

  • (Boolean) —

    true if signature matches provided public key.

Raises:

  • (SignatureError) —

    if it cannot determine the type of data or public key.



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# File 'lib/klay/signature.rb', line 116

def verify(blob, signature, public_key, chain_id = Chain::CYPRESS)
  recovered_key = nil
  if blob.instance_of? Array or blob.instance_of? Hash

    # recover Array from sign_typed_data
    recovered_key = recover_typed_data blob, signature, chain_id
  elsif blob.instance_of? String and blob.encoding != Encoding::ASCII_8BIT

    # recover message from personal_sign
    recovered_key = personal_recover blob, signature, chain_id
  elsif blob.instance_of? String and (Util.is_hex? blob or blob.encoding == Encoding::ASCII_8BIT)

    # if nothing else, recover from arbitrary signature
    recovered_key = recover blob, signature, chain_id
  end

  # raise if we cannot determine the data format
  raise SignatureError, "Unknown data format to verify: #{blob}" if recovered_key.nil?

  if public_key.instance_of? Address

    # recovering using an Klay::Address
    address = public_key.to_s
    recovered_address = Util.public_key_to_address(recovered_key).to_s
    return address == recovered_address
  elsif public_key.instance_of? Secp256k1::PublicKey

    # recovering using an Secp256k1::PublicKey
    public_hex = Util.bin_to_hex public_key.uncompressed
    return public_hex == recovered_key
  elsif public_key.size == 42

    # recovering using an address String
    address = Address.new(public_key).to_s
    recovered_address = Util.public_key_to_address(recovered_key).to_s
    return address == recovered_address
  elsif public_key.size == 130

    # recovering using an uncompressed public key String
    return public_key == recovered_key
  else

    # raise if we cannot determine the public key format used
    raise SignatureError, "Invalid public key or address supplied #{public_key}!"
  end
end

Instance Method Details

#dissect(signature) ⇒ String

Dissects a signature blob of 65+ bytes into its r, s, and v values.

Parameters:

  • signature (String) —

    a concatenated Secp256k1 signature string.

Returns:

  • (String, String, String) —

    the r, s, and v values.

Raises:



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# File 'lib/klay/signature.rb', line 50

def dissect(signature)
  signature = Util.bin_to_hex signature unless Util.is_hex? signature
  signature = Util.remove_hex_prefix signature
  if signature.size != 130
    raise SignatureError, "Unknown signature length #{signature.size}!"
  end
  r = signature[0...64]
  s = signature[64...128]
  v = signature[128..]
  return r, s, v
end

#personal_recover(message, signature, chain_id = Chain::CYPRESS) ⇒ String

Recovers a public key from a prefixed, personal message and a signature on a given chain. (EIP-191) Ref: https://eips.ethereum.org/EIPS/eip-191

Parameters:

  • message (String) —

    the message string.

  • signature (String) —

    the hex string containing the signature.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID the signature should be recovered from.

Returns:

  • (String) —

    a hexa-decimal, uncompressed public key.



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# File 'lib/klay/signature.rb', line 89

def personal_recover(message, signature, chain_id = Chain::CYPRESS)
  prefixed_message = prefix_message message
  hashed_message = Util.keccak256 prefixed_message
  recover hashed_message, signature, chain_id
end

#prefix_message(message) ⇒ String

Prefix message as per EIP-191 with 0x19 to ensure the data is not valid RLP and thus not mistaken for a transaction. EIP-191 Version byte: 0x45 (E) Ref: https://eips.ethereum.org/EIPS/eip-191

Parameters:

  • message (String) —

    the message string to be prefixed.

Returns:

  • (String) —

    an EIP-191 prefixed string.



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# File 'lib/klay/signature.rb', line 40

def prefix_message(message)
  "\u0019Klaytn Signed Message:\n#{message.size}#{message}"
end

#recover(blob, signature, chain_id = Chain::CYPRESS) ⇒ String

Recovers a signature from arbitrary data without validation on a given chain.

Parameters:

  • blob (String) —

    that arbitrary data to be recovered.

  • signature (String) —

    the hex string containing the signature.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID the signature should be recovered from.

Returns:

  • (String) —

    a hexa-decimal, uncompressed public key.

Raises:



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# File 'lib/klay/signature.rb', line 69

def recover(blob, signature, chain_id = Chain::CYPRESS)
  context = Secp256k1::Context.new
  r, s, v = dissect signature
  v = v.to_i(16)
  # raise SignatureError, "Invalid signature v byte #{v} for chain ID #{chain_id}!" if v != 130
  recovery_id = Chain.to_recovery_id v, chain_id
  signature_rs = Util.hex_to_bin "#{r}#{s}"
  recoverable_signature = context.recoverable_signature_from_compact signature_rs, recovery_id
  public_key = recoverable_signature.recover_public_key blob
  Util.bin_to_hex public_key.uncompressed
end

#recover_typed_data(typed_data, signature, chain_id = Chain::CYPRESS) ⇒ String

Recovers a public key from a typed data structure and a signature on a given chain. (EIP-712) Ref: https://eips.ethereum.org/EIPS/eip-712

Parameters:

  • typed_data (Array) —

    all the data in the typed data structure to be recovered.

  • signature (String) —

    the hex string containing the signature.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID the signature should be recovered from.

Returns:

  • (String) —

    a hexa-decimal, uncompressed public key.



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# File 'lib/klay/signature.rb', line 103

def recover_typed_data(typed_data, signature, chain_id = Chain::CYPRESS)
  hash_to_sign = Eip712.hash typed_data
  recover hash_to_sign, signature, chain_id
end

#verify(blob, signature, public_key, chain_id = Chain::CYPRESS) ⇒ Boolean

Verifies a signature for a given public key or address.

Parameters:

  • blob (String) —

    that arbitrary data to be verified.

  • signature (String) —

    the hex string containing the signature.

  • public_key (String) —

    either a public key or an Klaytn address.

  • chain_id (Integer) (defaults to: Chain::CYPRESS) —

    the chain ID used to sign.

Returns:

  • (Boolean) —

    true if signature matches provided public key.

Raises:

  • (SignatureError) —

    if it cannot determine the type of data or public key.



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# File 'lib/klay/signature.rb', line 116

def verify(blob, signature, public_key, chain_id = Chain::CYPRESS)
  recovered_key = nil
  if blob.instance_of? Array or blob.instance_of? Hash

    # recover Array from sign_typed_data
    recovered_key = recover_typed_data blob, signature, chain_id
  elsif blob.instance_of? String and blob.encoding != Encoding::ASCII_8BIT

    # recover message from personal_sign
    recovered_key = personal_recover blob, signature, chain_id
  elsif blob.instance_of? String and (Util.is_hex? blob or blob.encoding == Encoding::ASCII_8BIT)

    # if nothing else, recover from arbitrary signature
    recovered_key = recover blob, signature, chain_id
  end

  # raise if we cannot determine the data format
  raise SignatureError, "Unknown data format to verify: #{blob}" if recovered_key.nil?

  if public_key.instance_of? Address

    # recovering using an Klay::Address
    address = public_key.to_s
    recovered_address = Util.public_key_to_address(recovered_key).to_s
    return address == recovered_address
  elsif public_key.instance_of? Secp256k1::PublicKey

    # recovering using an Secp256k1::PublicKey
    public_hex = Util.bin_to_hex public_key.uncompressed
    return public_hex == recovered_key
  elsif public_key.size == 42

    # recovering using an address String
    address = Address.new(public_key).to_s
    recovered_address = Util.public_key_to_address(recovered_key).to_s
    return address == recovered_address
  elsif public_key.size == 130

    # recovering using an uncompressed public key String
    return public_key == recovered_key
  else

    # raise if we cannot determine the public key format used
    raise SignatureError, "Invalid public key or address supplied #{public_key}!"
  end
end