icepick.toml: make derivation prefix and derivation algorithm optional

crates/icepick/src/cli/mod.rs

@@ -49,13 +49,25 @@ pub fn derive_keys(
 
 #[derive(Serialize, Deserialize, Debug)]
 struct ModuleConfig {
+    /// The name of the module.
     name: String,
+
+    /// The name of the command used to invoke the module. If not given, the default would be
+    /// `format!("icepick-{name}")`, using the name of the module.
     command_name: Option<String>,
-    algorithm: keyfork_derive_util::request::DerivationAlgorithm,
 
+    /// The bip32 derivation algorithm. This is currently used for deriving keys from Keyfork, but
+    /// may be passed to modules within the workflow to provide additional context, such as the
+    /// algorithm for a generic signer.
+    algorithm: Option<DerivationAlgorithm>,
+
+    /// The bip44 derivation prefix. This is currently used for deriving keys from Keyfork directly
+    /// within Icepick, but may be passed to modules within the workflow to provide additional
+    /// context, such as a module for deriving keys.
     #[serde(with = "serde_derivation")]
-    derivation_prefix: keyfork_derive_util::DerivationPath,
+    derivation_prefix: Option<DerivationPath>,
 
+    /// All workflows for a module.
     #[serde(rename = "workflow", default)]
     workflows: Vec<workflow::Workflow>,
 }
@@ -65,21 +77,28 @@ mod serde_derivation {
     use serde::{Deserialize, Deserializer, Serializer};
     use std::str::FromStr;
 
-    pub fn serialize<S>(p: &DerivationPath, serializer: S) -> Result<S::Ok, S::Error>
+    pub fn serialize<S>(p: &Option<DerivationPath>, serializer: S) -> Result<S::Ok, S::Error>
     where
         S: Serializer,
     {
-        let path = p.to_string();
-        serializer.serialize_str(&path)
+        if let Some(p) = p {
+            let path = p.to_string();
+            serializer.serialize_str(&path)
+        } else {
+            serializer.serialize_none()
+        }
     }
 
-    pub fn deserialize<'de, D>(deserializer: D) -> Result<DerivationPath, D::Error>
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Option<DerivationPath>, D::Error>
     where
         D: Deserializer<'de>,
     {
         use serde::de::Error;
-        String::deserialize(deserializer)
-            .and_then(|string| DerivationPath::from_str(&string).map_err(Error::custom))
+
+        let opt_string = Option::<String>::deserialize(deserializer)?;
+        opt_string
+            .map(|string| DerivationPath::from_str(&string).map_err(Error::custom))
+            .transpose()
     }
 }
 
@@ -249,7 +268,11 @@ pub fn do_cli_thing() {
                     let accounts: Vec<keyfork_derive_util::DerivationIndex> =
                         serde_json::from_value(accounts.clone())
                             .expect("valid derivation_accounts");
-                    derived_keys.extend(derive_keys(&algo, &path, &accounts));
+                    derived_keys.extend(derive_keys(
+                        &algo.expect("a module requested keys but didn't provide algorithm"),
+                        &path.expect("a module requested keys but didn't provide prefix"),
+                        &accounts,
+                    ));
                 }
 
                 let json = serde_json::json!({

crates/icepick/src/cli/workflow.rs

@@ -198,7 +198,14 @@ impl Workflow {
                 .expect("could not find module config");
             let algo = &config.algorithm;
             let path_prefix = &config.derivation_prefix;
-            derived_keys.extend(derive_keys(algo, path_prefix, &derivation_accounts));
+            derived_keys.extend(derive_keys(
+                algo.as_ref()
+                    .expect("a module requested keys but didn't provide algorithm"),
+                path_prefix
+                    .as_ref()
+                    .expect("a module requested keys but didn't provide prefix"),
+                &derivation_accounts,
+            ));
             derivation_accounts.clear();
 
             // Prepare all inputs for the operation invocation