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Version: 2.15.0

EcdsaSignature

Defined in: lib/provable/crypto/foreign-ecdsa.ts:25

Constructors​

Constructor​

new EcdsaSignature(signature: {
  r:   | number
     | bigint
     | Field3
     | AlmostForeignField;
  s:   | number
     | bigint
     | Field3
     | AlmostForeignField;
}): EcdsaSignature;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:34

Create a new EcdsaSignature from an object containing the scalars r and s.

Note: Inputs must be range checked if they originate from a different field with a different modulus or if they are not constants. Please refer to the ForeignField constructor comments for more details.

Parameters​

signature​
r​

| number | bigint | Field3 | AlmostForeignField

s​

| number | bigint | Field3 | AlmostForeignField

Returns​

EcdsaSignature

Properties​

r​

r: AlmostForeignField;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:26

s​

s: AlmostForeignField;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:27

_Curve?​

static optional _Curve?: typeof ForeignCurve;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:215

_provable?​

static optional _provable?: ProvablePureExtended<EcdsaSignature, {
  r: bigint;
  s: bigint;
}, {
  r: string;
  s: string;
}>;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:216

Accessors​

Constructor​

Get Signature​

get Constructor(): typeof EcdsaSignature;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:212

Returns​

typeof EcdsaSignature

Curve​

Get Signature​

get static Curve(): typeof ForeignCurve;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:225

The ForeignCurve on which the ECDSA signature is defined.

Returns​

typeof ForeignCurve

provable​

Get Signature​

get static provable(): ProvablePureExtended<EcdsaSignature, {
  r: bigint;
  s: bigint;
}, {
  r: string;
  s: string;
}>;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:232

Provable<EcdsaSignature>

Returns​

ProvablePureExtended<EcdsaSignature, { r: bigint; s: bigint; }, { r: string; s: string; }>

Methods​

toBigInt()​

toBigInt(): {
  r: bigint;
  s: bigint;
};

Defined in: lib/provable/crypto/foreign-ecdsa.ts:62

Convert this signature to an object with bigint fields.

Returns​

{
  r: bigint;
  s: bigint;
}
r​
r: bigint;
s​
s: bigint;

verify()​

verify(message: Bytes, publicKey: FlexiblePoint): Bool;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:100

Verify the ECDSA signature given the message (an array of bytes) and public key (a Curve point).

Important: This method returns a Bool which indicates whether the signature is valid. So, to actually prove validity of a signature, you need to assert that the result is true.

Parameters​

message​

Bytes

publicKey​

FlexiblePoint

Returns​

Bool

Throws​

if one of the signature scalars is zero or if the public key is not on the curve.

Example​

// create classes for your curve
class Secp256k1 extends createForeignCurve(Crypto.CurveParams.Secp256k1) {}
class Scalar extends Secp256k1.Scalar {}
class Ecdsa extends createEcdsa(Secp256k1) {}

let message = 'my message';
let messageBytes = new TextEncoder().encode(message);

// outside provable code: create inputs
let privateKey = Scalar.random();
let publicKey = Secp256k1.generator.scale(privateKey);
let signature = Ecdsa.sign(messageBytes, privateKey.toBigInt());

// ...
// in provable code: create input witnesses (or use method inputs, or constants)
let pk = Provable.witness(Secp256k1, () => publicKey);
let msg = Provable.witness(Provable.Array(Field, 9), () => messageBytes.map(Field));
let sig = Provable.witness(Ecdsa, () => signature);

// verify signature
let isValid = sig.verify(msg, pk);
isValid.assertTrue('signature verifies');

verifyEthers()​

verifyEthers(message: Bytes, publicKey: FlexiblePoint): Bool;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:145

Verify an ECDSA signature generated by the ethers.js library, given the message (as a byte array) and a public key (a Curve point). The message digest used for signing follows the format defined in EIP-191, with the Ethereum-specific prefix.

Important: This method returns a Bool which indicates whether the signature is valid. So, to actually prove validity of a signature, you need to assert that the result is true.

Note: This method is specifically designed to verify signatures generated by ethers.js. Ensure that the curve being used is Secp256k1, as demonstrated in the example.

Parameters​

message​

Bytes

The original message as a byte array.

publicKey​

FlexiblePoint

The public key as a point on the Secp256k1 elliptic curve.

Returns​

Bool

  • A Bool indicating the validity of the signature.

Throws​

An error will be thrown if one of the signature scalars is zero or if the public key does not lie on the curve.

Example​

import { Wallet } from 'ethers';

// create the class for Secp256k1 curve
class Secp256k1 extends createForeignCurve(Crypto.CurveParams.Secp256k1) {}
class Ecdsa extends createEcdsa(Secp256k1) {}

// outside provable code: create inputs
let message = 'my message';
let signatureRaw = await wallet.signMessage(message);
let compressedPublicKey = wallet.signingKey.compressedPublicKey;

// this also works for uncompressed public keys (wallet.signingKey.publicKey)
let publicKey = Secp256k1.fromEthers(compressedPublicKey.slice(2));
let signature = Ecdsa.fromHex(signatureRaw);

// ...
// in provable code: create input witnesses (or use method inputs, or constants)
// and verify the signature
let isValid = signature.verifyEthers(Bytes.fromString(message), publicKey);
isValid.assertTrue('signature verifies');

verifySignedHash()​

verifySignedHash(msgHash: 
  | bigint
  | Bytes
  | AlmostForeignField, publicKey: FlexiblePoint): Bool;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:162

Verify the ECDSA signature given the message hash (a Scalar) and public key (a Curve point).

This is a building block of EcdsaSignature.verify, where the input message is also hashed. In contrast, this method just takes the message hash (a curve scalar, or the output bytes of a hash function) as input, giving you flexibility in choosing the hashing algorithm.

Parameters​

msgHash​

| bigint | Bytes | AlmostForeignField

publicKey​

FlexiblePoint

Returns​

Bool

check()​

static check(signature: EcdsaSignature): void;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:204

Parameters​

signature​

EcdsaSignature

Returns​

void

from()​

static from(signature: FlexibleSignature): EcdsaSignature;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:45

Coerce the input to a EcdsaSignature.

Parameters​

signature​

FlexibleSignature

Returns​

EcdsaSignature

fromHex()​

static fromHex(rawSignature: string): EcdsaSignature;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:54

Create an EcdsaSignature from a raw 130-char hex string as used in Ethereum transactions.

Parameters​

rawSignature​

string

Returns​

EcdsaSignature

sign()​

static sign(message: Uint8Array | (number | bigint)[], privateKey: bigint): EcdsaSignature;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:181

Create an EcdsaSignature by signing a message with a private key.

Note: This method is not provable, and only takes JS bigints as input.

Parameters​

message​

Uint8Array | (number | bigint)[]

privateKey​

bigint

Returns​

EcdsaSignature

signHash()​

static signHash(msgHash: bigint | Bytes, privateKey: bigint): EcdsaSignature;

Defined in: lib/provable/crypto/foreign-ecdsa.ts:196

Create an EcdsaSignature by signing a message hash with a private key.

This is a building block of EcdsaSignature.sign, where the input message is also hashed. In contrast, this method just takes the message hash (a curve scalar, or the output bytes of a hash function) as input, giving you flexibility in choosing the hashing algorithm.

Note: This method is not provable, and only takes JS bigints or constant Bytes as input.

Parameters​

msgHash​

bigint | Bytes

privateKey​

bigint

Returns​

EcdsaSignature