37 lines
1.0 KiB
JavaScript
37 lines
1.0 KiB
JavaScript
async function hashToCurve(secretMessage) {
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console.log(
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'### secretMessage',
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nobleSecp256k1.utils.bytesToHex(secretMessage)
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)
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let point
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while (!point) {
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const hash = await nobleSecp256k1.utils.sha256(secretMessage)
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const hashHex = nobleSecp256k1.utils.bytesToHex(hash)
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const pointX = '02' + hashHex
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console.log('### pointX', pointX)
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try {
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point = nobleSecp256k1.Point.fromHex(pointX)
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console.log('### point', point.toHex())
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} catch (error) {
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secretMessage = await nobleSecp256k1.utils.sha256(secretMessage)
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}
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}
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return point
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}
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async function step1Bob(secretMessage) {
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const Y = await hashToCurve(secretMessage)
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const randomBlindingFactor = bytesToNumber(
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nobleSecp256k1.utils.randomPrivateKey()
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)
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const P = nobleSecp256k1.Point.fromPrivateKey(randomBlindingFactor)
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const B_ = Y.add(P)
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return {B_: B_.toHex(true), randomBlindingFactor}
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}
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function step3Bob(C_, r, A) {
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const rInt = BigInt(r)
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const C = C_.subtract(A.multiply(rInt))
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return C
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}
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