Feat/custom verification method (#1334)

* Add support for arbitrary (custom) verification method data

* wasm bindings

* custom method type + wasm

* workaround serde's issue

* Update bindings/wasm/src/verification/wasm_method_data.rs

Co-authored-by: Abdulrahim Al Methiab <31316147+abdulmth@users.noreply.github.com>

* review comments

* fmt

* review comment

---------

Co-authored-by: Abdulrahim Al Methiab <31316147+abdulmth@users.noreply.github.com>

bindings/wasm/src/verification/wasm_method_data.rs

@@ -1,6 +1,7 @@
 // Copyright 2020-2023 IOTA Stiftung
 // SPDX-License-Identifier: Apache-2.0
 
+use identity_iota::verification::CustomMethodData;
 use identity_iota::verification::MethodData;
 use wasm_bindgen::prelude::*;
 
@@ -45,22 +46,23 @@ impl WasmMethodData {
     Ok(Self(MethodData::PublicKeyJwk(key.0.clone())))
   }
 
-  /// Creates a new {@link MethodData} variant in CAIP-10 format.
-  #[wasm_bindgen(js_name = newBlockchainAccountId)]
-  pub fn new_blockchain_account_id(data: String) -> Self {
-    Self(MethodData::new_blockchain_account_id(data))
+  /// Creates a new custom {@link MethodData}.
+  #[wasm_bindgen(js_name = newCustom)]
+  pub fn new_custom(name: String, data: JsValue) -> Result<WasmMethodData> {
+    let data = data.into_serde::<serde_json::Value>().wasm_result()?;
+    Ok(Self(MethodData::Custom(CustomMethodData { name, data })))
   }
 
-  /// Returns the wrapped blockchain account id if the format is `BlockchainAccountId`.
-  #[wasm_bindgen(js_name = tryBlockchainAccountId)]
-  pub fn try_blockchain_account_id(&self) -> Result<String> {
+  /// Returns the wrapped custom method data format is `Custom`.
+  #[wasm_bindgen(js_name = tryCustom)]
+  pub fn try_custom(&self) -> Result<WasmCustomMethodData> {
     self
       .0
-      .blockchain_account_id()
-      .map(|id| id.to_string())
+      .custom()
+      .map(|custom| custom.clone().into())
       .ok_or(WasmError::new(
         Cow::Borrowed("MethodDataFormatError"),
-        Cow::Borrowed("method data format is not BlockchainAccountId"),
+        Cow::Borrowed("method data format is not Custom"),
       ))
       .wasm_result()
   }
@@ -98,3 +100,31 @@ impl From<MethodData> for WasmMethodData {
     WasmMethodData(data)
   }
 }
+
+/// A custom verification method data format.
+#[wasm_bindgen(js_name = CustomMethodData, inspectable)]
+pub struct WasmCustomMethodData(pub(crate) CustomMethodData);
+
+#[wasm_bindgen(js_class = CustomMethodData)]
+impl WasmCustomMethodData {
+  #[wasm_bindgen(constructor)]
+  pub fn new(name: String, data: JsValue) -> Result<WasmCustomMethodData> {
+    let data = data.into_serde::<serde_json::Value>().wasm_result()?;
+    Ok(Self(CustomMethodData { name, data }))
+  }
+}
+
+impl From<CustomMethodData> for WasmCustomMethodData {
+  fn from(value: CustomMethodData) -> Self {
+    Self(value)
+  }
+}
+
+impl From<WasmCustomMethodData> for CustomMethodData {
+  fn from(value: WasmCustomMethodData) -> Self {
+    value.0
+  }
+}
+
+impl_wasm_clone!(WasmCustomMethodData, CustomMethodData);
+impl_wasm_json!(WasmCustomMethodData, CustomMethodData);

bindings/wasm/src/verification/wasm_method_type.rs

@@ -27,10 +27,9 @@ impl WasmMethodType {
     WasmMethodType(MethodType::JSON_WEB_KEY)
   }
 
-  /// The `EcdsaSecp256k1RecoverySignature2020` method type.
-  #[wasm_bindgen(js_name = EcdsaSecp256k1RecoverySignature2020)]
-  pub fn ecdsa_secp256k1_recovery_signature_2020() -> WasmMethodType {
-    WasmMethodType(MethodType::ECDSA_SECP256K1_RECOVERY_SIGNATURE_2020)
+  /// A custom method.
+  pub fn custom(type_: String) -> WasmMethodType {
+    WasmMethodType(MethodType::custom(type_))
   }
 
   /// Returns the {@link MethodType} as a string.

identity_verification/Cargo.toml

@@ -13,8 +13,8 @@ identity_core = { version = "=1.1.1", path = "./../identity_core", default-featu
 identity_did = { version = "=1.1.1", path = "./../identity_did", default-features = false }
 identity_jose = { version = "=1.1.1", path = "./../identity_jose", default-features = false }
 serde.workspace = true
+serde_json.workspace = true
 strum.workspace = true
 thiserror.workspace = true
 
 [dev-dependencies]
-serde_json.workspace = true

identity_verification/src/verification_method/material.rs

@@ -5,6 +5,12 @@ use crate::jose::jwk::Jwk;
 use core::fmt::Debug;
 use core::fmt::Formatter;
 use identity_core::convert::BaseEncoding;
+use serde::de::Visitor;
+use serde::ser::SerializeMap;
+use serde::Deserialize;
+use serde::Serialize;
+use serde::Serializer;
+use serde_json::Value;
 
 use crate::error::Error;
 use crate::error::Result;
@@ -21,9 +27,9 @@ pub enum MethodData {
   PublicKeyBase58(String),
   /// Verification Material in the JSON Web Key format.
   PublicKeyJwk(Jwk),
-  /// Verification Material in CAIP-10 format.
-  /// [CAIP-10](https://github.com/ChainAgnostic/CAIPs/blob/main/CAIPs/caip-10.md)
-  BlockchainAccountId(String),
+  /// Arbitrary verification material.
+  #[serde(untagged)]
+  Custom(CustomMethodData),
 }
 
 impl MethodData {
@@ -39,9 +45,9 @@ impl MethodData {
     Self::PublicKeyMultibase(BaseEncoding::encode_multibase(&data, None))
   }
 
-  /// Verification Material in CAIP-10 format.
-  pub fn new_blockchain_account_id(data: String) -> Self {
-    Self::BlockchainAccountId(data)
+  /// Creates a new `MethodData` variant from custom data.
+  pub fn new_custom(data: impl Into<CustomMethodData>) -> Self {
+    Self::Custom(data.into())
   }
 
   /// Returns a `Vec<u8>` containing the decoded bytes of the `MethodData`.
@@ -53,7 +59,7 @@ impl MethodData {
   /// represented as a vector of bytes.
   pub fn try_decode(&self) -> Result<Vec<u8>> {
     match self {
-      Self::PublicKeyJwk(_) | Self::BlockchainAccountId(_) => Err(Error::InvalidMethodDataTransformation(
+      Self::PublicKeyJwk(_) | Self::Custom(_) => Err(Error::InvalidMethodDataTransformation(
         "method data is not base encoded",
       )),
       Self::PublicKeyMultibase(input) => {
@@ -77,10 +83,10 @@ impl MethodData {
     self.public_key_jwk().ok_or(Error::NotPublicKeyJwk)
   }
 
-  /// Returns the wrapped Blockchain Account Id if the format is [`MethodData::BlockchainAccountId`].
-  pub fn blockchain_account_id(&self) -> Option<&str> {
-    if let Self::BlockchainAccountId(id) = self {
-      Some(id)
+  /// Returns the custom method data, if any.
+  pub fn custom(&self) -> Option<&CustomMethodData> {
+    if let Self::Custom(method_data) = self {
+      Some(method_data)
     } else {
       None
     }
@@ -93,7 +99,94 @@ impl Debug for MethodData {
       Self::PublicKeyJwk(inner) => f.write_fmt(format_args!("PublicKeyJwk({inner:#?})")),
       Self::PublicKeyMultibase(inner) => f.write_fmt(format_args!("PublicKeyMultibase({inner})")),
       Self::PublicKeyBase58(inner) => f.write_fmt(format_args!("PublicKeyBase58({inner})")),
-      Self::BlockchainAccountId(inner) => f.write_fmt(format_args!("BlockchainAccountId({inner})")),
+      Self::Custom(CustomMethodData { name, data }) => f.write_fmt(format_args!("{name}({data})")),
     }
   }
 }
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+/// Custom verification method.
+pub struct CustomMethodData {
+  /// Verification method's name.
+  pub name: String,
+  /// Verification method's data.
+  pub data: Value,
+}
+
+impl Serialize for CustomMethodData {
+  fn serialize<S>(&self, serializer: S) -> std::prelude::v1::Result<S::Ok, S::Error>
+  where
+    S: Serializer,
+  {
+    let mut map = serializer.serialize_map(Some(1))?;
+    map.serialize_entry(&self.name, &self.data)?;
+    map.end()
+  }
+}
+
+impl<'de> Deserialize<'de> for CustomMethodData {
+  fn deserialize<D>(deserializer: D) -> std::prelude::v1::Result<Self, D::Error>
+  where
+    D: serde::Deserializer<'de>,
+  {
+    deserializer.deserialize_map(CustomMethodDataVisitor)
+  }
+}
+
+struct CustomMethodDataVisitor;
+
+impl<'de> Visitor<'de> for CustomMethodDataVisitor {
+  type Value = CustomMethodData;
+  fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    formatter.write_str("\"<any property name>\": <any json value>")
+  }
+  fn visit_map<A>(self, mut map: A) -> std::prelude::v1::Result<Self::Value, A::Error>
+  where
+    A: serde::de::MapAccess<'de>,
+  {
+    let mut custom_method_data = CustomMethodData {
+      name: String::default(),
+      data: Value::Null,
+    };
+    while let Some((name, data)) = map.next_entry::<String, Value>()? {
+      custom_method_data = CustomMethodData { name, data };
+    }
+
+    Ok(custom_method_data)
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use serde_json::json;
+
+  #[test]
+  fn serialize_custom_method_data() {
+    let custom = MethodData::Custom(CustomMethodData {
+      name: "anArbitraryMethod".to_owned(),
+      data: json!({"a": 1, "b": 2}),
+    });
+    let target_str = json!({
+      "anArbitraryMethod": {"a": 1, "b": 2},
+    })
+    .to_string();
+    assert_eq!(serde_json::to_string(&custom).unwrap(), target_str);
+  }
+  #[test]
+  fn deserialize_custom_method_data() {
+    let inner_data = json!({
+        "firstCustomField": "a random string",
+        "secondCustomField": 420,
+    });
+    let json_method_data = json!({
+      "myCustomVerificationMethod": &inner_data,
+    });
+    let custom = serde_json::from_value::<MethodData>(json_method_data.clone()).unwrap();
+    let target_method_data = MethodData::Custom(CustomMethodData {
+      name: "myCustomVerificationMethod".to_owned(),
+      data: inner_data,
+    });
+    assert_eq!(custom, target_method_data);
+  }
+}

identity_verification/src/verification_method/method.rs

@@ -20,6 +20,7 @@ use crate::verification_method::MethodBuilder;
 use crate::verification_method::MethodData;
 use crate::verification_method::MethodRef;
 use crate::verification_method::MethodType;
+use crate::CustomMethodData;
 use identity_did::CoreDID;
 use identity_did::DIDUrl;
 use identity_did::DID;
@@ -28,8 +29,8 @@ use identity_did::DID;
 ///
 /// [Specification](https://www.w3.org/TR/did-core/#verification-method-properties)
 #[derive(Clone, Debug, PartialEq, Eq, Deserialize, Serialize)]
+#[serde(from = "_VerificationMethod")]
 pub struct VerificationMethod {
-  #[serde(deserialize_with = "deserialize_id_with_fragment")]
   pub(crate) id: DIDUrl,
   pub(crate) controller: CoreDID,
   #[serde(rename = "type")]
@@ -245,3 +246,46 @@ impl KeyComparable for VerificationMethod {
     self.id()
   }
 }
+
+// Horrible workaround for a tracked serde issue https://github.com/serde-rs/serde/issues/2200. Serde doesn't "consume"
+// the input when deserializing flattened enums (MethodData in this case) causing duplication of data (in this case
+// it ends up in the properties object). This workaround simply removes the duplication.
+#[derive(Deserialize)]
+struct _VerificationMethod {
+  #[serde(deserialize_with = "deserialize_id_with_fragment")]
+  pub(crate) id: DIDUrl,
+  pub(crate) controller: CoreDID,
+  #[serde(rename = "type")]
+  pub(crate) type_: MethodType,
+  #[serde(flatten)]
+  pub(crate) data: MethodData,
+  #[serde(flatten)]
+  pub(crate) properties: Object,
+}
+
+impl From<_VerificationMethod> for VerificationMethod {
+  fn from(value: _VerificationMethod) -> Self {
+    let _VerificationMethod {
+      id,
+      controller,
+      type_,
+      data,
+      mut properties,
+    } = value;
+    let key = match &data {
+      MethodData::PublicKeyBase58(_) => "publicKeyBase58",
+      MethodData::PublicKeyJwk(_) => "publicKeyJwk",
+      MethodData::PublicKeyMultibase(_) => "publicKeyMultibase",
+      MethodData::Custom(CustomMethodData { name, .. }) => name.as_str(),
+    };
+    properties.remove(key);
+
+    VerificationMethod {
+      id,
+      controller,
+      type_,
+      data,
+      properties,
+    }
+  }
+}

identity_verification/src/verification_method/method_type.rs

@@ -12,7 +12,6 @@ use crate::error::Result;
 const ED25519_VERIFICATION_KEY_2018_STR: &str = "Ed25519VerificationKey2018";
 const X25519_KEY_AGREEMENT_KEY_2019_STR: &str = "X25519KeyAgreementKey2019";
 const JSON_WEB_KEY_METHOD_TYPE: &str = "JsonWebKey";
-const ECDSA_SECP256K1_RECOVERY_SIGNATURE_2020_STR: &str = "EcdsaSecp256k1RecoverySignature2020";
 
 /// verification method types.
 #[derive(Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord, Deserialize, Serialize)]
@@ -26,9 +25,10 @@ impl MethodType {
   /// A verification method for use with JWT verification as prescribed by the [`Jwk`](::identity_jose::jwk::Jwk)
   /// in the [`publicKeyJwk`](crate::MethodData::PublicKeyJwk) entry.
   pub const JSON_WEB_KEY: Self = Self(Cow::Borrowed(JSON_WEB_KEY_METHOD_TYPE));
-  /// The `EcdsaSecp256k1RecoverySignature2020` method type.
-  pub const ECDSA_SECP256K1_RECOVERY_SIGNATURE_2020: Self =
-    Self(Cow::Borrowed(ECDSA_SECP256K1_RECOVERY_SIGNATURE_2020_STR));
+  /// Construct a custom method type.
+  pub fn custom(type_: impl AsRef<str>) -> Self {
+    Self(Cow::Owned(type_.as_ref().to_owned()))
+  }
 }
 
 impl MethodType {
@@ -58,7 +58,6 @@ impl FromStr for MethodType {
       ED25519_VERIFICATION_KEY_2018_STR => Ok(Self::ED25519_VERIFICATION_KEY_2018),
       X25519_KEY_AGREEMENT_KEY_2019_STR => Ok(Self::X25519_KEY_AGREEMENT_KEY_2019),
       JSON_WEB_KEY_METHOD_TYPE => Ok(Self::JSON_WEB_KEY),
-      ECDSA_SECP256K1_RECOVERY_SIGNATURE_2020_STR => Ok(Self::ECDSA_SECP256K1_RECOVERY_SIGNATURE_2020),
       _ => Ok(Self(Cow::Owned(string.to_owned()))),
     }
   }

identity_verification/src/verification_method/mod.rs

@@ -15,6 +15,7 @@ mod method_scope;
 mod method_type;
 
 pub use self::builder::MethodBuilder;
+pub use self::material::CustomMethodData;
 pub use self::material::MethodData;
 pub use self::method::VerificationMethod;
 pub use self::method_ref::MethodRef;