View Source ExSecp256k1 (ExSecp256k1 v0.5.0)
NIF for secp256k1 curve functions.
Link to this section Summary
Functions
Create a public key from a private key
Tweak public key by adding to it
Tweak private key by multiplying it
Compresses public key
Decompresses public key
Tweak public key by adding to it
Tweak public key by multiplying it
Recover public key from a message, its signature and a recovery id
Recover public key from a message, its compact signature and a recovery id
Sign a message with the provided private key
Sign a message with the provided private key. It returns a compact signature
Verify a signature of a message
Link to this section Types
Specs
error() :: {:error, atom()}
Link to this section Functions
Specs
Create a public key from a private key
Examples
iex> private_key = :crypto.strong_rand_bytes(32)
iex> {:ok, _public_key} = ExSecp256k1.create_public_key(private_key)Specs
Tweak public key by adding to it
Examples
iex> private_key = <<72, 91, 33, 135, 186, 13, 21, 144, 75, 36, 27, 203, 157, 203, 177, 166, 86, 92, 151, 137, 148, 205, 234, 174, 192, 12, 9, 227, 208, 173, 74, 69>>
iex> {:ok, _result} = ExSecp256k1.private_key_tweak_add(private_key, private_key)Specs
Tweak private key by multiplying it
Examples
iex> private_key = <<72, 91, 33, 135, 186, 13, 21, 144, 75, 36, 27, 203, 157, 203, 177, 166, 86, 92, 151, 137, 148, 205, 234, 174, 192, 12, 9, 227, 208, 173, 74, 69>>
iex> {:ok, _result} = ExSecp256k1.private_key_tweak_mult(private_key, private_key)Specs
Compresses public key
Examples
iex> public_key = <<4, 204, 170, 92, 229, 234, 207, 153, 33, 250, 27, 208, 37, 71, 183, 155, 104, 155, 45, 114, 7, 156, 83, 199, 245, 83, 32, 128, 45, 174, 96, 24, 38, 220, 210, 198, 20, 132, 174, 75, 63, 131, 95, 120, 101, 186, 93, 179, 95, 14, 206, 46, 48, 6, 129, 8, 146, 40, 135, 251, 42, 71, 4, 83, 222>>
iex> {:ok, _result} = ExSecp256k1.public_key_compress(public_key)Specs
Decompresses public key
Examples
iex> public_key = <<2, 204, 170, 92, 229, 234, 207, 153, 33, 250, 27, 208, 37, 71, 183, 155, 104, 155, 45, 114, 7, 156, 83, 199, 245, 83, 32, 128, 45, 174, 96, 24, 38>>
iex> {:ok, _result} = ExSecp256k1.public_key_decompress(public_key)Specs
Tweak public key by adding to it
Examples
iex> public_key = <<4, 204, 170, 92, 229, 234, 207, 153, 33, 250, 27, 208, 37, 71, 183, 155, 104, 155, 45, 114, 7, 156, 83, 199, 245, 83, 32, 128, 45, 174, 96, 24, 38, 220, 210, 198, 20, 132, 174, 75, 63, 131, 95, 120, 101, 186, 93, 179, 95, 14, 206, 46, 48, 6, 129, 8, 146, 40, 135, 251, 42, 71, 4, 83, 222>>
iex> tweak_key = <<50, 8, 92, 222, 223, 155, 132, 50, 53, 227, 114, 79, 88, 11, 248, 24, 239, 76, 236, 39, 195, 198, 112, 133, 224, 41, 65, 138, 91, 47, 111, 43>>
iex> {:ok, _result} = ExSecp256k1.public_key_tweak_add(public_key, tweak_key)Specs
Tweak public key by multiplying it
Examples
iex> public_key = <<4, 204, 170, 92, 229, 234, 207, 153, 33, 250, 27, 208, 37, 71, 183, 155, 104, 155, 45, 114, 7, 156, 83, 199, 245, 83, 32, 128, 45, 174, 96, 24, 38, 220, 210, 198, 20, 132, 174, 75, 63, 131, 95, 120, 101, 186, 93, 179, 95, 14, 206, 46, 48, 6, 129, 8, 146, 40, 135, 251, 42, 71, 4, 83, 222>>
iex> tweak_key = <<50, 8, 92, 222, 223, 155, 132, 50, 53, 227, 114, 79, 88, 11, 248, 24, 239, 76, 236, 39, 195, 198, 112, 133, 224, 41, 65, 138, 91, 47, 111, 43>>
iex> {:ok, _result} = ExSecp256k1.public_key_tweak_mult(public_key, tweak_key)Specs
Recover public key from a message, its signature and a recovery id
Examples
iex> hash = <<218, 245, 167, 121, 174, 151, 47, 151, 33, 151, 48, 61, 123, 87, 71, 70, 199, 239, 131, 234, 218, 192, 242, 121, 26, 210, 61, 185, 46, 76, 142, 83>>
iex> r = <<40, 239, 97, 52, 11, 217, 57, 188, 33, 149, 254, 83, 117, 103, 134, 96, 3, 225, 161, 93, 60, 113, 255, 99, 225, 89, 6, 32, 170, 99, 98, 118>>
iex> s = <<103, 203, 233, 216, 153, 127, 118, 26, 236, 183, 3, 48, 75, 56, 0, 204, 245, 85, 201, 243, 220, 100, 33, 75, 41, 127, 177, 150, 106, 59, 109, 131>>
iex> recovery_id = 0
iex> {:ok, _public_key_binary} = ExSecp256k1.recover(hash, r, s, recovery_id)
iex> {:error, :recovery_failure} = ExSecp256k1.recover(hash, r, s, 2)Specs
recover_compact(binary(), binary(), non_neg_integer()) :: {:ok, binary()} | error()
Recover public key from a message, its compact signature and a recovery id
Examples
iex> hash = <<218, 245, 167, 121, 174, 151, 47, 151, 33, 151, 48, 61, 123, 87, 71, 70, 199, 239, 131, 234, 218, 192, 242, 121, 26, 210, 61, 185, 46, 76, 142, 83>>
iex> r = <<40, 239, 97, 52, 11, 217, 57, 188, 33, 149, 254, 83, 117, 103, 134, 96, 3, 225, 161, 93, 60, 113, 255, 99, 225, 89, 6, 32, 170, 99, 98, 118>>
iex> s = <<103, 203, 233, 216, 153, 127, 118, 26, 236, 183, 3, 48, 75, 56, 0, 204, 245, 85, 201, 243, 220, 100, 33, 75, 41, 127, 177, 150, 106, 59, 109, 131>>
iex> recovery_id = 0
iex> {:ok, _public_key_binary} = ExSecp256k1.recover_compact(hash, r <> s, recovery_id)
iex> {:error, :recovery_failure} = ExSecp256k1.recover_compact(hash, r <> s, 2)Specs
Sign a message with the provided private key
Examples
iex> message = <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2>>
iex> private_key = <<120, 128, 174, 201, 52, 19, 241, 23, 239, 20, 189, 78, 109, 19, 8, 117, 171, 44, 125, 125, 85, 160, 100, 250, 195, 194, 247, 189, 81, 81, 99, 128>>
iex> {:ok, {_r_binary, _s_binary, _recovery_id_int}} = ExSecp256k1.sign(message, private_key)Specs
sign_compact(binary(), binary()) :: {:ok, {binary(), non_neg_integer()}} | error()
Sign a message with the provided private key. It returns a compact signature
Examples
iex> message = <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2>>
iex> private_key = <<120, 128, 174, 201, 52, 19, 241, 23, 239, 20, 189, 78, 109, 19, 8, 117, 171, 44, 125, 125, 85, 160, 100, 250, 195, 194, 247, 189, 81, 81, 99, 128>>
iex> {:ok, {_signature_bin, _recovery_id_int}} = ExSecp256k1.sign_compact(message, private_key)Specs
Verify a signature of a message
Examples
iex> message = :crypto.strong_rand_bytes(32)
iex> private_key = :crypto.strong_rand_bytes(32)
iex> {:ok, {signature, _r}} = ExSecp256k1.sign_compact(message, private_key)
iex> {:ok, public_key} = ExSecp256k1.create_public_key(private_key)
iex> :ok = ExSecp256k1.verify(message, signature, public_key)