Add option_independent_secrets channel type

.msggen.json

@@ -2550,6 +2550,7 @@
             "ListConfigs.configs.htlc-minimum-msat": 43,
             "ListConfigs.configs.ignore-fee-limits": 32,
             "ListConfigs.configs.important-plugin": 9,
+            "ListConfigs.configs.independent-secrets": 76,
             "ListConfigs.configs.large-channels": 20,
             "ListConfigs.configs.lightning-dir": 12,
             "ListConfigs.configs.log-file": 60,
@@ -2559,6 +2560,7 @@
             "ListConfigs.configs.mainnet": 5,
             "ListConfigs.configs.max-concurrent-htlcs": 42,
             "ListConfigs.configs.max-dust-htlc-exposure-msat": 45,
+            "ListConfigs.configs.max-independent-secrets": 77,
             "ListConfigs.configs.max-locktime-blocks": 34,
             "ListConfigs.configs.min-capacity-sat": 46,
             "ListConfigs.configs.network": 13,
@@ -2770,6 +2772,10 @@
             "ListConfigs.configs.important-plugin.sources[]": 2,
             "ListConfigs.configs.important-plugin.values_str[]": 1
         },
+        "ListconfigsConfigsIndependent-secrets": {
+            "ListConfigs.configs.independent-secrets.set": 1,
+            "ListConfigs.configs.independent-secrets.source": 2
+        },
         "ListconfigsConfigsLarge-channels": {
             "ListConfigs.configs.large-channels.set": 1,
             "ListConfigs.configs.large-channels.source": 2
@@ -2806,6 +2812,10 @@
             "ListConfigs.configs.max-dust-htlc-exposure-msat.source": 2,
             "ListConfigs.configs.max-dust-htlc-exposure-msat.value_msat": 1
         },
+        "ListconfigsConfigsMax-independent-secrets": {
+            "ListConfigs.configs.max-independent-secrets.source": 1,
+            "ListConfigs.configs.max-independent-secrets.value_int": 2
+        },
         "ListconfigsConfigsMax-locktime-blocks": {
             "ListConfigs.configs.max-locktime-blocks.source": 2,
             "ListConfigs.configs.max-locktime-blocks.value_int": 1
@@ -3242,6 +3252,7 @@
             "ListPeerChannels.channels[].in_offered_msat": 45,
             "ListPeerChannels.channels[].in_payments_fulfilled": 46,
             "ListPeerChannels.channels[].in_payments_offered": 44,
+            "ListPeerChannels.channels[].independent_secrets_stored": 64,
             "ListPeerChannels.channels[].inflight[]": 16,
             "ListPeerChannels.channels[].initial_feerate": 12,
             "ListPeerChannels.channels[].last_feerate": 13,
@@ -10287,6 +10298,18 @@
             "added": "v23.08",
             "deprecated": null
         },
+        "ListConfigs.configs.independent-secrets": {
+            "added": "v26.06.9-blake2b.9",
+            "deprecated": null
+        },
+        "ListConfigs.configs.independent-secrets.set": {
+            "added": "v26.06.9-blake2b.9",
+            "deprecated": null
+        },
+        "ListConfigs.configs.independent-secrets.source": {
+            "added": "v26.06.9-blake2b.9",
+            "deprecated": null
+        },
         "ListConfigs.configs.large-channels": {
             "added": "v23.08",
             "deprecated": null
@@ -10395,6 +10418,18 @@
             "added": "v23.08",
             "deprecated": null
         },
+        "ListConfigs.configs.max-independent-secrets": {
+            "added": "v26.06.9-blake2b.9",
+            "deprecated": null
+        },
+        "ListConfigs.configs.max-independent-secrets.source": {
+            "added": "v26.06.9-blake2b.9",
+            "deprecated": null
+        },
+        "ListConfigs.configs.max-independent-secrets.value_int": {
+            "added": "v26.06.9-blake2b.9",
+            "deprecated": null
+        },
         "ListConfigs.configs.max-locktime-blocks": {
             "added": "pre-v0.10.1",
             "deprecated": "v24.05"
@@ -11771,6 +11806,10 @@
             "added": "v23.02",
             "deprecated": null
         },
+        "ListPeerChannels.channels[].independent_secrets_stored": {
+            "added": "v26.06.9-blake2b.9",
+            "deprecated": null
+        },
         "ListPeerChannels.channels[].inflight[]": {
             "added": "v23.02",
             "deprecated": null

README.md

@@ -10,12 +10,13 @@ This is an unofficial version of [Core Lightning](https://github.com/ElementsPro
 - **Unified signatures.** Wallet transactions and new channels are signed with the opt-in `SIGHASH_UNIFIED` digest, so a channel funded past activation from coins received past activation is signed in a way a node that has not upgraded rejects, and cannot be replayed on the SHA256d fork. Built on [connorslab's](https://github.com/connorslab/lightning) unified-sigs work.
 - **A required peer feature bit.** The node advertises `option_blake2b` as compulsory, so it will not connect to a Lightning node that has not upgraded.
 - **Downgrades are refused.** A build without unified signing computes a different signature hash and could not close the channels this one opens, so `lightning-downgrade` stops before touching the database.
+- **Independent per-commitment secrets.** With `--independent-secrets` (off by default), on a new channel with a peer which also offers `option_independent_secrets`, the node accepts per-commitment secrets that don't come from a shachain and keeps each one it needs to punish a breach, so the peer can generate them k-of-n and no single signer can give away the secret of its current state. Secrets from a peer which uses a shachain still go in one, so nothing changes with such a peer. See [doc/independent-secrets.md](doc/independent-secrets.md).
 
 ## Before opening channels
 
 The required feature bit means you **cannot cooperatively close a channel opened before activation** with a counterparty that has not upgraded.
 
-The feature bits are the ones proposed for BOLT 9: 512 for `option_blake2b` and 514 for `option_unified_sigs`. A stored channel type using the earlier bit 70 is moved to 514 on upgrade.
+The feature bits are the ones proposed for BOLT 9: 512 for `option_blake2b` and 514 for `option_unified_sigs`. `option_independent_secrets` uses 266, from [lightning-blake2b/bolts#17](https://github.com/lightning-blake2b/bolts/pull/17). A stored channel type using the earlier bit 70 is moved to 514 on upgrade.
 
 Fund channels only from coins received past activation. A channel funded from a coin received before activation has a funding transaction a node that has not upgraded also accepts, which reopens the exposure unified signing exists to close.
 

cln-grpc/proto/primitives.proto

@@ -130,6 +130,7 @@ enum ChannelTypeName {
   zeroconf_even = 4;
   anchors_even = 5;
   unified_sigs_even = 6;
+  independent_secrets_even = 7;
 }
 
 enum AutocleanSubsystem {

cln-rpc/src/primitives.rs

@@ -75,6 +75,8 @@ pub enum ChannelTypeName {
     ANCHORS_EVEN = 5,
     #[serde(rename = "unified_sigs/even")]
     UNIFIED_SIGS_EVEN = 6,
+    #[serde(rename = "independent_secrets/even")]
+    INDEPENDENT_SECRETS_EVEN = 7,
 }
 
 #[derive(Copy, Clone, Serialize, Deserialize, Debug)]
@@ -502,6 +504,7 @@ impl From<i32> for ChannelTypeName {
             4 => ChannelTypeName::ZEROCONF_EVEN,
             5 => ChannelTypeName::ANCHORS_EVEN,
             6 => ChannelTypeName::UNIFIED_SIGS_EVEN,
+            7 => ChannelTypeName::INDEPENDENT_SECRETS_EVEN,
             o => panic!("Unmapped ChannelTypeName {}", o),
         }
     }
@@ -517,6 +520,7 @@ impl From<ChannelTypeName> for i32 {
             ChannelTypeName::ZEROCONF_EVEN => 4,
             ChannelTypeName::ANCHORS_EVEN => 5,
             ChannelTypeName::UNIFIED_SIGS_EVEN => 6,
+            ChannelTypeName::INDEPENDENT_SECRETS_EVEN => 7,
         }
     }
 }
@@ -533,6 +537,7 @@ impl Display for ChannelTypeName {
             ChannelTypeName::ZEROCONF_EVEN => write!(f, "ZEROCONF_EVEN"),
             ChannelTypeName::ANCHORS_EVEN => write!(f, "ANCHORS_EVEN"),
             ChannelTypeName::UNIFIED_SIGS_EVEN => write!(f, "UNIFIED_SIGS_EVEN"),
+            ChannelTypeName::INDEPENDENT_SECRETS_EVEN => write!(f, "INDEPENDENT_SECRETS_EVEN"),
         }
     }
 }

common/channel_type.c

@@ -62,6 +62,12 @@ void channel_type_set_unified_sigs(struct channel_type *type)
 			COMPULSORY_FEATURE(OPT_UNIFIED_SIGS));
 }
 
+void channel_type_set_independent_secrets(struct channel_type *type)
+{
+	set_feature_bit(&type->features,
+			COMPULSORY_FEATURE(OPT_INDEPENDENT_SECRETS));
+}
+
 void channel_type_set_scid_alias(struct channel_type *type)
 {
 	set_feature_bit(&type->features,
@@ -132,6 +138,7 @@ struct channel_type *channel_type_accept(const tal_t *ctx,
 
 	static const size_t feats[] = {
 		OPT_UNIFIED_SIGS,
+		OPT_INDEPENDENT_SECRETS,
 		OPT_ANCHORS_ZERO_FEE_HTLC_TX,
 		OPT_STATIC_REMOTEKEY,
 		OPT_SCID_ALIAS,
@@ -145,6 +152,7 @@ struct channel_type *channel_type_accept(const tal_t *ctx,
 	 */
 	static const size_t variants[] = {
 		OPT_UNIFIED_SIGS,
+		OPT_INDEPENDENT_SECRETS,
 		OPT_SCID_ALIAS,
 		OPT_ZEROCONF,
 	};

common/channel_type.h

@@ -13,6 +13,8 @@ struct channel_type *channel_type_anchors_zero_fee_htlc(const tal_t *ctx);
 /* channel_type variants */
 void channel_type_set_zeroconf(struct channel_type *channel_type);
 void channel_type_set_unified_sigs(struct channel_type *channel_type);
+/* Add option_independent_secrets to a channel type. */
+void channel_type_set_independent_secrets(struct channel_type *channel_type);
 void channel_type_set_scid_alias(struct channel_type *channel_type);
 
 /* Duplicate a channel_type */

common/features.c

@@ -47,6 +47,12 @@ static const struct feature_style feature_styles[] = {
 	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT_AS_OPTIONAL,
 			  [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT_AS_OPTIONAL,
 			  [CHANNEL_TYPE_FEATURE] = FEATURE_REPRESENT } },
+	/* We store every per-commitment secret on channels which have it, so
+	 * a peer may generate them however it likes (e.g. k-of-n). */
+	{ OPT_INDEPENDENT_SECRETS,
+	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT,
+			  [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT,
+			  [CHANNEL_TYPE_FEATURE] = FEATURE_REPRESENT } },
 	{ OPT_DATA_LOSS_PROTECT,
 	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT,
 			  [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT } },
@@ -174,6 +180,8 @@ static const struct dependency feature_deps[] = {
 	{ OPT_BASIC_MPP, OPT_PAYMENT_SECRET },
 	/* The unified hash does not exist without the rules that define it. */
 	{ OPT_UNIFIED_SIGS, OPT_BLAKE2B },
+	/* Only ever agreed in channel_type. */
+	{ OPT_INDEPENDENT_SECRETS, OPT_CHANNEL_TYPE },
 };
 
 static void trim_features(u8 **features)
@@ -512,6 +520,9 @@ const char *feature_name(const tal_t *ctx, size_t f)
 		return tal_fmt(ctx, "option_blake2b/%s", (f & 1) ? "odd" : "even");
 	if (COMPULSORY_FEATURE(f) == OPT_UNIFIED_SIGS)
 		return tal_fmt(ctx, "option_unified_sigs/%s", (f & 1) ? "odd" : "even");
+	if (COMPULSORY_FEATURE(f) == OPT_INDEPENDENT_SECRETS)
+		return tal_fmt(ctx, "option_independent_secrets/%s",
+			       (f & 1) ? "odd" : "even");
 	if (f / 2 >= ARRAY_SIZE(fnames) || !fnames[f / 2])
 		return tal_fmt(ctx, "option_unknown_%zu/%s",
 			       COMPULSORY_FEATURE(f), (f & 1) ? "odd" : "even");

common/features.h

@@ -161,5 +161,9 @@ struct feature_set *feature_set_dup(const tal_t *ctx,
 #define OPT_BLAKE2B 512
 /* Provisional signing capability; persisted as a channel type modifier. */
 #define OPT_UNIFIED_SIGS 514
+/* From lightning-blake2b/bolts#17: the peer's per-commitment secrets need
+ * not come from a shachain, so we keep every one.  A channel type
+ * modifier. */
+#define OPT_INDEPENDENT_SECRETS 266
 
 #endif /* LIGHTNING_COMMON_FEATURES_H */

common/hsm_version.h

@@ -35,6 +35,7 @@
  * v6 with bip86_base in TLV: 6bb6e6ee256f22a6fb41856c90feebde3065a9074e79a46731e453a932be83f0
  * v6 with hsmd_sign_local_htlc_tx removed: 0e28ca3699196cf9d26d38f8f621d1bf68c76cf5e2cdc1f4157a6937b02dc2f6
  * v6 with sign_htlc_tx_mingle_unified: 290bcb0cc0c03319fc0f1a91d6e396ac9e80c77c709da0d2905b98f058714059
+ * v6 with dev_independent_secrets_sender: 287b3bca10c5514c49efa04abaec19ecf09272406c63a06104e4676f525aec16
  */
 #define HSM_MIN_VERSION 5
 #define HSM_MAX_VERSION 6