ecdsa: remove unused functions
This commit is contained in:
Daniel Cousens
parent
87cb018466
commit
7cdabef954
3 changed files with 0 additions and 206 deletions
85
src/ecdsa.js
85
src/ecdsa.js
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@ -154,93 +154,8 @@ function verify (hash, signature, Q) {
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return v.equals(r)
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}
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/**
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* Recover a public key from a signature.
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*
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* See SEC 1: Elliptic Curve Cryptography, section 4.1.6, "Public
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* Key Recovery Operation".
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*
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* http://www.secg.org/download/aid-780/sec1-v2.pdf
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*/
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function recoverPubKey (e, signature, i) {
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typeforce(types.tuple(
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types.BigInt,
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types.ECSignature,
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types.UInt2
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), arguments)
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var n = secp256k1.n
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var G = secp256k1.G
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var r = signature.r
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var s = signature.s
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if (r.signum() <= 0 || r.compareTo(n) >= 0) throw new Error('Invalid r value')
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if (s.signum() <= 0 || s.compareTo(n) >= 0) throw new Error('Invalid s value')
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// A set LSB signifies that the y-coordinate is odd
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var isYOdd = i & 1
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// The more significant bit specifies whether we should use the
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// first or second candidate key.
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var isSecondKey = i >> 1
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// 1.1 Let x = r + jn
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var x = isSecondKey ? r.add(n) : r
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var R = secp256k1.pointFromX(isYOdd, x)
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// 1.4 Check that nR is at infinity
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var nR = R.multiply(n)
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if (!secp256k1.isInfinity(nR)) throw new Error('nR is not a valid curve point')
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// Compute r^-1
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var rInv = r.modInverse(n)
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// Compute -e from e
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var eNeg = e.negate().mod(n)
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// 1.6.1 Compute Q = r^-1 (sR - eG)
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// Q = r^-1 (sR + -eG)
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var Q = R.multiplyTwo(s, G, eNeg).multiply(rInv)
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secp256k1.validate(Q)
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return Q
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}
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/**
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* Calculate pubkey extraction parameter.
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*
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* When extracting a pubkey from a signature, we have to
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* distinguish four different cases. Rather than putting this
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* burden on the verifier, Bitcoin includes a 2-bit value with the
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* signature.
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*
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* This function simply tries all four cases and returns the value
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* that resulted in a successful pubkey recovery.
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*/
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function calcPubKeyRecoveryParam (e, signature, Q) {
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typeforce(types.tuple(
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types.BigInt,
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types.ECSignature,
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types.ECPoint
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), arguments)
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for (var i = 0; i < 4; i++) {
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var Qprime = recoverPubKey(e, signature, i)
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// 1.6.2 Verify Q
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if (Qprime.equals(Q)) {
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return i
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}
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}
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throw new Error('Unable to find valid recovery factor')
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}
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module.exports = {
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calcPubKeyRecoveryParam: calcPubKeyRecoveryParam,
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deterministicGenerateK: deterministicGenerateK,
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recoverPubKey: recoverPubKey,
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sign: sign,
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verify: verify,
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@ -81,55 +81,6 @@ describe('ecdsa', function () {
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})
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})
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describe('recoverPubKey', function () {
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fixtures.valid.ecdsa.forEach(function (f) {
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it('recovers the pubKey for ' + f.d, function () {
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var d = BigInteger.fromHex(f.d)
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var Q = curve.G.multiply(d)
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var signature = ECSignature.fromDER(new Buffer(f.signature, 'hex'))
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var h1 = bcrypto.sha256(f.message)
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var e = BigInteger.fromBuffer(h1)
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var Qprime = ecdsa.recoverPubKey(e, signature, f.i)
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assert(Qprime.equals(Q))
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})
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})
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describe('with i ∈ {0,1,2,3}', function () {
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var hash = new Buffer('feef89995d7575f12d65ccc9d28ccaf7ab224c2e59dad4cc7f6a2b0708d24696', 'hex')
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var e = BigInteger.fromBuffer(hash)
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var signatureBuffer = new Buffer('INcvXVVEFyIfHLbDX+xoxlKFn3Wzj9g0UbhObXdMq+YMKC252o5RHFr0/cKdQe1WsBLUBi4morhgZ77obDJVuV0=', 'base64')
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var signature = ECSignature.parseCompact(signatureBuffer).signature
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var points = [
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'03e3a8c44a8bf712f1fbacee274fb19c0239b1a9e877eff0075ea335f2be8ff380',
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'0279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798',
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'03d49e765f0bc27525c51a1b98fb1c99dacd59abe85a203af90f758260550b56c5',
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'027eea09d46ac7fb6aa2e96f9c576677214ffdc238eb167734a9b39d1eb4c3d30d'
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]
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points.forEach(function (expectedHex, i) {
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it('recovers an expected point for i of ' + i, function () {
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var Qprime = ecdsa.recoverPubKey(e, signature, i)
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var QprimeHex = Qprime.getEncoded().toString('hex')
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assert.strictEqual(QprimeHex, expectedHex)
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})
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})
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})
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fixtures.invalid.recoverPubKey.forEach(function (f) {
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it('throws on ' + f.description + ' (' + f.exception + ')', function () {
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var e = BigInteger.fromHex(f.e)
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var signature = new ECSignature(new BigInteger(f.signatureRaw.r, 16), new BigInteger(f.signatureRaw.s, 16))
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assert.throws(function () {
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ecdsa.recoverPubKey(e, signature, f.i)
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}, new RegExp(f.exception))
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})
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})
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})
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describe('sign', function () {
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fixtures.valid.ecdsa.forEach(function (f) {
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it('produces a deterministic signature for "' + f.message + '"', function () {
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72
test/fixtures/ecdsa.json
vendored
72
test/fixtures/ecdsa.json
vendored
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@ -125,78 +125,6 @@
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]
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},
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"invalid": {
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"recoverPubKey": [
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{
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"description": "Invalid r value (< 0)",
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"exception": "Invalid r value",
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"e": "01",
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"signatureRaw": {
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"r": "-01",
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"s": "02"
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},
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"i": 0
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},
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{
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"description": "Invalid r value (== 0)",
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"exception": "Invalid r value",
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"e": "01",
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"signatureRaw": {
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"r": "00",
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"s": "02"
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},
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"i": 0
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},
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{
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"description": "Invalid s value (< 0)",
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"exception": "Invalid s value",
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"e": "01",
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"signatureRaw": {
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"r": "02",
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"s": "-01"
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},
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"i": 0
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},
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{
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"description": "Invalid s value (== 0)",
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"exception": "Invalid s value",
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"e": "01",
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"signatureRaw": {
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"r": "02",
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"s": "00"
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},
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"i": 0
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},
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{
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"description": "Invalid r value (nR is infinity)",
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"exception": "nR is not a valid curve point",
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"e": "01",
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"signatureRaw": {
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"r": "fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364140",
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"s": "01"
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},
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"i": 0
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},
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{
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"description": "Invalid curve point",
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"exception": "Point is not on the curve",
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"e": "01",
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"signatureRaw": {
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"r": "4b3b4ca85a86c47a098a223fffffffff",
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"s": "01"
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},
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"i": 0
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},
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{
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"description": "Invalid i value (> 3)",
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"exception": "Expected property \"2\" of type UInt2, got Number 4",
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"e": "01",
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"signatureRaw": {
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"r": "00",
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"s": "02"
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},
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"i": 4
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}
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],
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"verify": [
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{
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"description": "The wrong signature",
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