[WIP] Add AS-aware relay selection

Cargo-minimal.lock

@@ -215,6 +215,12 @@ dependencies = [
  "winnow 0.7.15",
 ]
 
+[[package]]
+name = "asmap"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "996e3818c450a9497e2f1aff7306d1c56b4198a07880222ee0aa85b6c42ac81f"
+
 [[package]]
 name = "asn1-rs"
 version = "0.7.1"
@@ -2784,6 +2790,7 @@ name = "payjoin-cli"
 version = "0.2.0"
 dependencies = [
  "anyhow",
+ "asmap",
  "async-trait",
  "bitcoind-async-client",
  "clap 4.6.0",

Cargo-recent.lock

@@ -215,6 +215,12 @@ dependencies = [
  "winnow",
 ]
 
+[[package]]
+name = "asmap"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "996e3818c450a9497e2f1aff7306d1c56b4198a07880222ee0aa85b6c42ac81f"
+
 [[package]]
 name = "asn1-rs"
 version = "0.7.1"
@@ -1950,7 +1956,7 @@ dependencies = [
  "tokio",
  "tokio-rustls 0.26.2",
  "tower-service",
- "webpki-roots 1.0.2",
+ "webpki-roots 1.0.7",
 ]
 
 [[package]]
@@ -2752,6 +2758,7 @@ name = "payjoin-cli"
 version = "0.2.0"
 dependencies = [
  "anyhow",
+ "asmap",
  "async-trait",
  "bitcoind-async-client",
  "clap 4.5.46",
@@ -3404,7 +3411,7 @@ dependencies = [
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "web-sys",
- "webpki-roots 1.0.2",
+ "webpki-roots 1.0.7",
 ]
 
 [[package]]
@@ -4332,7 +4339,7 @@ dependencies = [
  "time",
  "tokio",
  "tokio-rustls 0.26.2",
- "webpki-roots 1.0.2",
+ "webpki-roots 1.0.7",
  "x509-parser 0.18.0",
 ]
 
@@ -5094,14 +5101,14 @@ version = "0.26.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "521bc38abb08001b01866da9f51eb7c5d647a19260e00054a8c7fd5f9e57f7a9"
 dependencies = [
- "webpki-roots 1.0.2",
+ "webpki-roots 1.0.7",
 ]
 
 [[package]]
 name = "webpki-roots"
-version = "1.0.2"
+version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e8983c3ab33d6fb807cfcdad2491c4ea8cbc8ed839181c7dfd9c67c83e261b2"
+checksum = "52f5ee44c96cf55f1b349600768e3ece3a8f26010c05265ab73f945bb1a2eb9d"
 dependencies = [
  "rustls-pki-types",
 ]

payjoin-cli/Cargo.toml

@@ -20,13 +20,15 @@ path = "src/main.rs"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [features]
 default = ["v2"]
+asmap = ["dep:asmap"]
 native-certs = ["reqwest/rustls-tls-native-roots"]
-_manual-tls = ["reqwest/rustls-tls", "payjoin/_manual-tls", "tokio-rustls"]
+_manual-tls = ["reqwest/rustls-tls", "payjoin/_manual-tls"]
 v1 = ["payjoin/v1", "hyper", "hyper-util", "http-body-util"]
 v2 = ["payjoin/v2", "payjoin/io"]
 
 [dependencies]
 anyhow = "1.0.99"
+asmap = { version = "0.1.0", optional = true }
 async-trait = "0.1.89"
 bitcoind-async-client = "0.10.2"
 clap = { version = "4.5.45", features = ["derive"] }
@@ -48,7 +50,7 @@ serde_json = "1.0.149"
 tokio = { version = "1.47.1", features = ["full"] }
 tokio-rustls = { version = "0.26.2", features = [
   "ring",
-], default-features = false, optional = true }
+], default-features = false }
 tracing = "0.1.41"
 tracing-subscriber = { version = "0.3.19", features = ["env-filter"] }
 

payjoin-cli/README.md

@@ -75,7 +75,7 @@ rpchost = "http://localhost:18443/wallet/sender"
 
 # For v2, our config also requires a payjoin directory server and OHTTP relay
 [v2]
-pj_directory = "https://payjo.in"
+pj_directories = ["https://payjo.in"]
 ohttp_relays = ["https://pj.benalleng.com", "https://pj.bobspacebkk.com", "https://ohttp.achow101.com"]
 ```
 
@@ -90,7 +90,7 @@ rpchost = "http://localhost:18443/wallet/receiver"
 
 # For v2, our config also requires a payjoin directory server and OHTTP relay
 [v2]
-pj_directory = "https://payjo.in"
+pj_directories = ["https://payjo.in"]
 ohttp_relays = ["https://pj.benalleng.com", "https://pj.bobspacebkk.com", "https://ohttp.achow101.com"]
 ```
 
@@ -138,6 +138,30 @@ See the
 [example.config.toml](https://github.com/payjoin/rust-payjoin/blob/fde867b93ede767c9a50913432a73782a94ef40b/payjoin-cli/example.config.toml)
 for inspiration.
 
+`payjoin-cli` also supports optional AS-aware filtering for BIP77 relay
+selection:
+
+```toml
+[v2]
+pj_directories = ["https://payjo.in", "https://backup.example"]
+ohttp_relays = ["https://relay-1.example", "https://relay-2.example"]
+
+[v2.asmap]
+asmap_file = "./ip_asn.dat"
+user_public_ips = ["198.51.100.10"]
+user_asns = [64512]
+```
+
+Build `payjoin-cli` with `--features asmap` to enable the `[v2.asmap]`
+configuration block.
+
+When enabled, directories and relays that resolve into the same ASN as the
+configured user identity are excluded, mixed-ASN hostnames are rejected, and
+relay ordering becomes deterministic from the receiver key embedded in the
+BIP77 URI. This mitigates some AS-level correlation risks, but it does not
+eliminate traffic analysis when sender and receiver already share the same
+network.
+
 ### Asynchronous Operation
 
 Sender and receiver state is saved to a database in the directory from which `payjoin-cli` is run, called `payjoin.sqlite`. Once a send or receive session is started, it may resume using the `resume` argument if prior payjoin sessions have not yet complete.

payjoin-cli/example.config.toml

@@ -48,9 +48,19 @@ rpcpassword = "password"
 
 # Version 2 Configuration
 # [v2]
-# pj_directory = "https://payjo.in"
+# pj_directories = ["https://payjo.in"]
 # ohttp_relays = ["https://pj.benalleng.com", "https://pj.bobspacebkk.com", "https://ohttp.achow101.com", "https://example.com"]
 # # Optional: The HPKE keys which need to be fetched ahead of time from the pj_endpoint
 # # for the payjoin packets to be encrypted.
 # # These can now be fetched and no longer need to be configured.
 # ohttp_keys = "./path/to/ohttp_keys"
+#
+# # Optional AS-aware relay and directory filtering.
+# # When enabled, payjoin-cli will reject directories/relays that share an
+# # ASN with the configured user identity, and will deterministically order
+# # relay selection from the remaining candidates.
+# # Requires building payjoin-cli with `--features asmap`.
+# [v2.asmap]
+# asmap_file = "./ip_asn.dat"
+# user_public_ips = ["198.51.100.10", "2001:db8::10"]
+# user_asns = [64512]