Skip to content

Commit

Permalink
Improve error handling for musig2 module
Browse files Browse the repository at this point in the history
  • Loading branch information
@sstone
sstone committed Jan 31, 2024
1 parent 018a49c commit eb10a83
Show file tree
Hide file tree
Showing 2 changed files with 95 additions and 66 deletions.
52 changes: 36 additions & 16 deletions src/commonMain/kotlin/fr/acinq/bitcoin/crypto/musig2/Musig2.kt
View file
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
package fr.acinq.bitcoin.crypto.musig2

import fr.acinq.bitcoin.*
import fr.acinq.bitcoin.utils.Either
import fr.acinq.secp256k1.Hex
import fr.acinq.secp256k1.Secp256k1
import kotlin.jvm.JvmStatic
Expand All @@ -23,14 +24,16 @@ public data class KeyAggCache(val data: ByteVector) {
* @param isXonly true if the tweak is an x-only tweak
* @return an updated cache, and the tweaked aggregated public key
*/
public fun tweak(tweak: ByteVector32, isXonly: Boolean): Pair<KeyAggCache, PublicKey> {
public fun tweak(tweak: ByteVector32, isXonly: Boolean): Either<Throwable, Pair<KeyAggCache, PublicKey>> = try {
val localCache = toByteArray()
val tweaked = if (isXonly) {
Secp256k1.musigPubkeyXonlyTweakAdd(localCache, tweak.toByteArray())
} else {
Secp256k1.musigPubkeyTweakAdd(localCache, tweak.toByteArray())
}
return Pair(KeyAggCache(localCache), PublicKey.parse(tweaked))
Either.Right(Pair(KeyAggCache(localCache), PublicKey.parse(tweaked)))
} catch (t: Throwable) {
Either.Left(t)
}

public companion object {
Expand All @@ -40,10 +43,12 @@ public data class KeyAggCache(val data: ByteVector) {
* @return a new (if cache was null) or updated cache, and the aggregated public key
*/
@JvmStatic
public fun add(pubkeys: List<PublicKey>, cache: KeyAggCache?): Pair<XonlyPublicKey, KeyAggCache> {
public fun add(pubkeys: List<PublicKey>, cache: KeyAggCache? = null): Either<Throwable, Pair<XonlyPublicKey, KeyAggCache>> = try {
val localCache = cache?.data?.toByteArray() ?: ByteArray(Secp256k1.MUSIG2_PUBLIC_KEYAGG_CACHE_SIZE)
val aggkey = Secp256k1.musigPubkeyAgg(pubkeys.map { it.value.toByteArray() }.toTypedArray(), localCache)
return Pair(XonlyPublicKey(aggkey.byteVector32()), KeyAggCache(localCache.byteVector()))
Either.Right(Pair(XonlyPublicKey(aggkey.byteVector32()), KeyAggCache(localCache.byteVector())))
} catch (t: Throwable) {
Either.Left(t)
}
}
}
Expand All @@ -64,8 +69,10 @@ public data class Session(val data: ByteVector) {
* @param aggCache key aggregation cache
* @return a Musig2 partial signature
*/
public fun sign(secretNonce: SecretNonce, pk: PrivateKey, aggCache: KeyAggCache): ByteVector32 {
return Secp256k1.musigPartialSign(secretNonce.data.toByteArray(), pk.value.toByteArray(), aggCache.data.toByteArray(), toByteArray()).byteVector32()
public fun sign(secretNonce: SecretNonce, pk: PrivateKey, aggCache: KeyAggCache): Either<Throwable, ByteVector32> = try {
Either.Right(Secp256k1.musigPartialSign(secretNonce.data.toByteArray(), pk.value.toByteArray(), aggCache.data.toByteArray(), toByteArray()).byteVector32())
} catch (t: Throwable) {
Either.Left(t)
}

/**
Expand All @@ -75,18 +82,23 @@ public data class Session(val data: ByteVector) {
* @param cache key aggregation cache
* @return true if the partial signature is valid
*/
public fun verify(psig: ByteVector32, pubnonce: IndividualNonce, pubkey: PublicKey, cache: KeyAggCache): Boolean {
return Secp256k1.musigPartialSigVerify(psig.toByteArray(), pubnonce.toByteArray(), pubkey.value.toByteArray(), cache.data.toByteArray(), toByteArray()) == 1
public fun verify(psig: ByteVector32, pubnonce: IndividualNonce, pubkey: PublicKey, cache: KeyAggCache): Boolean = try {
Secp256k1.musigPartialSigVerify(psig.toByteArray(), pubnonce.toByteArray(), pubkey.value.toByteArray(), cache.data.toByteArray(), toByteArray()) == 1
} catch (t: Throwable) {
false
}

/**
* @param psigs partial signatures
* @return the aggregate of all input partial signatures
*/
public fun add(psigs: List<ByteVector32>): ByteVector64 {
return Secp256k1.musigPartialSigAgg(toByteArray(), psigs.map { it.toByteArray() }.toTypedArray()).byteVector64()
public fun add(psigs: List<ByteVector32>): Either<Throwable, ByteVector64> = try {
Either.Right(Secp256k1.musigPartialSigAgg(toByteArray(), psigs.map { it.toByteArray() }.toTypedArray()).byteVector64())
} catch (t: Throwable) {
Either.Left(t)
}


public companion object {
/**
* @param aggregatedNonce aggregated public nonce
Expand All @@ -95,9 +107,11 @@ public data class Session(val data: ByteVector) {
* @return a Musig signing session
*/
@JvmStatic
public fun build(aggregatedNonce: AggregatedNonce, msg: ByteVector32, cache: KeyAggCache): Session {
public fun build(aggregatedNonce: AggregatedNonce, msg: ByteVector32, cache: KeyAggCache): Either<Throwable, Session> = try {
val session = Secp256k1.musigNonceProcess(aggregatedNonce.toByteArray(), msg.toByteArray(), cache.data.toByteArray())
return Session(session.byteVector())
Either.Right(Session(session.byteVector()))
} catch (t: Throwable) {
Either.Left(t)
}
}
}
Expand Down Expand Up @@ -125,9 +139,13 @@ public data class SecretNonce(val data: ByteVector) {
* @return a (secret nonce, public nonce) tuple
*/
@JvmStatic
public fun generate(sessionId: ByteVector32, seckey: PrivateKey?, pubkey: PublicKey, msg: ByteVector32?, cache: KeyAggCache?, extraInput: ByteVector32?): Pair<SecretNonce, IndividualNonce> {
public fun generate(sessionId: ByteVector32, seckey: PrivateKey?, pubkey: PublicKey, msg: ByteVector32?, cache: KeyAggCache?, extraInput: ByteVector32?): Either<Throwable, Pair<SecretNonce, IndividualNonce>> = try {
val nonce = Secp256k1.musigNonceGen(sessionId.toByteArray(), seckey?.value?.toByteArray(), pubkey.value.toByteArray(), msg?.toByteArray(), cache?.data?.toByteArray(), extraInput?.toByteArray())
return Pair(SecretNonce(nonce.copyOfRange(0, Secp256k1.MUSIG2_SECRET_NONCE_SIZE)), IndividualNonce(nonce.copyOfRange(Secp256k1.MUSIG2_SECRET_NONCE_SIZE, Secp256k1.MUSIG2_SECRET_NONCE_SIZE + Secp256k1.MUSIG2_PUBLIC_NONCE_SIZE)))
val secretNonce = SecretNonce(nonce.copyOfRange(0, Secp256k1.MUSIG2_SECRET_NONCE_SIZE))
val publicNonce = IndividualNonce(nonce.copyOfRange(Secp256k1.MUSIG2_SECRET_NONCE_SIZE, Secp256k1.MUSIG2_SECRET_NONCE_SIZE + Secp256k1.MUSIG2_PUBLIC_NONCE_SIZE))
Either.Right(Pair(secretNonce, publicNonce))
} catch (t: Throwable) {
Either.Left(t)
}
}
}
Expand All @@ -148,9 +166,11 @@ public data class IndividualNonce(val data: ByteVector) {

public companion object {
@JvmStatic
public fun aggregate(nonces: List<IndividualNonce>): AggregatedNonce {
public fun aggregate(nonces: List<IndividualNonce>): Either<Throwable, AggregatedNonce> = try {
val agg = Secp256k1.musigNonceAgg(nonces.map { it.toByteArray() }.toTypedArray())
return AggregatedNonce(agg)
Either.Right(AggregatedNonce(agg))
} catch (t: Throwable) {
Either.Left(t)
}
}
}
Expand Down
Loading

0 comments on commit eb10a83

Please sign in to comment.