Round hold times to decaseconds (#3112)

Hold times in attribution data now use decaseconds instead of milliseconds

Author: thomash-acinq

docs/release-notes/eclair-vnext.md

@@ -22,8 +22,8 @@ See https://github.com/lightning/bolts/pull/1044 for more details.
 
 Attribution data also provides hold times from payment relayers, both for fulfilled and failed HTLCs.
 
-Support is disabled by default as the spec is not yet final.
-It can be enabled by setting `eclair.features.option_attribution_data = optional` at the risk of being incompatible with the final spec.
+Support is enabled by default.
+It can be disabled by setting `eclair.features.option_attribution_data = disabled`.
 
 ### API changes
 

eclair-core/src/main/resources/reference.conf

@@ -74,7 +74,7 @@ eclair {
     option_shutdown_anysegwit = optional
     option_dual_fund = optional
     option_quiesce = optional
-    option_attribution_data = disabled
+    option_attribution_data = optional
     option_onion_messages = optional
     // This feature should only be enabled when acting as an LSP for mobile wallets.
     // When activating this feature, the peer-storage section should be customized to match desired SLAs.

eclair-core/src/main/scala/fr/acinq/eclair/crypto/Sphinx.scala

@@ -410,7 +410,7 @@ object Sphinx extends Logging {
       val previousAttribution = previousAttribution_opt.getOrElse(ByteVector.low(totalLength))
       val previousHmacs = getHmacs(previousAttribution).dropRight(1).map(_.drop(1))
       val mac = Hmac256(generateKey("um", sharedSecret))
-      val holdTimes = uint32.encode(holdTime.toMillis).require.bytes ++ previousAttribution.take((maxNumHops - 1) * holdTimeLength)
+      val holdTimes = uint32.encode(holdTime.toMillis / 100).require.bytes ++ previousAttribution.take((maxNumHops - 1) * holdTimeLength)
       val hmacs = computeHmacs(mac, failurePacket_opt.getOrElse(ByteVector.empty), holdTimes, previousHmacs, 0) +: previousHmacs
       cipher(holdTimes ++ ByteVector.concat(hmacs.map(ByteVector.concat(_))), sharedSecret)
     }
@@ -421,7 +421,7 @@ object Sphinx extends Logging {
      */
     def unwrap(encrypted: ByteVector, failurePacket: ByteVector, sharedSecret: ByteVector32, minNumHop: Int): Option[(FiniteDuration, ByteVector)] = {
       val bytes = cipher(encrypted, sharedSecret)
-      val holdTime = uint32.decode(bytes.take(holdTimeLength).bits).require.value.milliseconds
+      val holdTime = (uint32.decode(bytes.take(holdTimeLength).bits).require.value * 100).milliseconds
       val hmacs = getHmacs(bytes)
       val mac = Hmac256(generateKey("um", sharedSecret))
       if (computeHmacs(mac, failurePacket, bytes.take(maxNumHops * holdTimeLength), hmacs.drop(1), minNumHop) == hmacs.head.drop(minNumHop)) {