feat(silentpayments): add SilentPaymentCode command

The input for this command are two compressed public keys.

The network is obtained from the wallet current network.

The silent payment code generated is independent from any of the other
stateful features of bdk-cli.

This command is mainly intended for experimental use, do not lock any
funds to the generated code if you don't know what you are doing and
don't have the keys matchin the public keys used.

Author: nymius

src/commands.rs

@@ -110,6 +110,19 @@ pub enum CliSubCommand {
         #[command(flatten)]
         wallet_opts: WalletOpts,
     },
+    /// Silent payment code generation tool.
+    ///
+    /// Allows the encoding of two public keys into a silent payment code.
+    /// Useful to create silent payment transactions using fake silent payment codes.
+    #[cfg(feature = "sp")]
+    SilentPaymentCode {
+        /// The scan public key to use on the silent payment code.
+        #[arg(long = "scan_public_key")]
+        scan: bdk_sp::bitcoin::secp256k1::PublicKey,
+        /// The spend public key to use on the silent payment code.
+        #[arg(long = "spend_public_key")]
+        spend: bdk_sp::bitcoin::secp256k1::PublicKey,
+    }
 }
 
 /// Wallet operation subcommands.

src/handlers.rs

@@ -1049,6 +1049,30 @@ pub(crate) fn is_final(psbt: &Psbt) -> Result<(), Error> {
     Ok(())
 }
 
+#[cfg(feature = "sp")]
+pub(crate) fn handle_sp_subcommand(
+    scan_pubkey: bdk_sp::bitcoin::secp256k1::PublicKey,
+    spend_pubkey: bdk_sp::bitcoin::secp256k1::PublicKey,
+    network: Network,
+    pretty: bool,
+) -> Result<String, Error> {
+    let sp_code = SilentPaymentCode::new_v0(scan_pubkey, spend_pubkey, network);
+    if pretty {
+        let table = vec![vec![
+            "sp_code".cell().bold(true),
+            sp_code.to_string().cell(),
+        ]]
+        .table()
+        .display()
+        .map_err(|e| Error::Generic(e.to_string()))?;
+        Ok(format!("{table}"))
+    } else {
+        Ok(serde_json::to_string_pretty(
+            &json!({"sp_code": sp_code.to_string()}),
+        )?)
+    }
+}
+
 /// Handle a key sub-command
 ///
 /// Key sub-commands are described in [`KeySubCommand`].
@@ -1348,6 +1372,14 @@ pub(crate) async fn handle_command(cli_opts: CliOpts) -> Result<String, Error> {
             let result = handle_key_subcommand(network, key_subcommand, pretty)?;
             Ok(result)
         }
+        #[cfg(feature = "sp")]
+        CliSubCommand::SilentPaymentCode {
+            scan,
+            spend
+        } => {
+            let result = handle_sp_subcommand(scan, spend, network, pretty)?;
+            Ok(result)
+        }
         #[cfg(feature = "compiler")]
         CliSubCommand::Compile {
             policy,