feat(agent): add new agent derivation path

Signed-off-by: goncalo-frade-iohk <goncalo.frade@iohk.io>
hyperledger · Jul 5, 2024 · 0b302f5 · 0b302f5
1 parent fa46536
commit 0b302f5
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Showing 23 changed files with 326 additions and 35 deletions.
diff --git a/EdgeAgentSDK/Apollo/Sources/ApolloImpl+KeyRestoration.swift b/EdgeAgentSDK/Apollo/Sources/ApolloImpl+KeyRestoration.swift
@@ -15,26 +15,37 @@ extension ApolloImpl: KeyRestoration {
     }
 
     public func restorePrivateKey(_ key: StorableKey) throws -> PrivateKey {
+        let derivationPath: DerivationPath?
+        if let derivationStr = key.queryDerivationPath {
+            derivationPath = try DerivationPath(string: derivationStr)
+        } else if let index = key.index {
+            derivationPath = DerivationPath(index: index)
+        } else {
+            derivationPath = nil
+        }
         switch  key.restorationIdentifier {
         case "secp256k1+priv":
-            guard let index = key.index else {
+            guard let derivationPath else {
                 throw ApolloError.restoratonFailedNoIdentifierOrInvalid
             }
             return Secp256k1PrivateKey(
                 identifier: key.identifier,
-                internalKey: .init(raw: key.storableData.toKotlinByteArray()), derivationPath: DerivationPath(index: index)
+                internalKey: .init(raw: key.storableData.toKotlinByteArray()),
+                derivationPath: derivationPath
             )
         case "x25519+priv":
             return try CreateX25519KeyPairOperation(logger: Self.logger)
                 .compute(
                     identifier: key.identifier,
-                    fromPrivateKey: key.storableData
+                    fromPrivateKey: key.storableData,
+                    derivationPath: derivationPath
                 )
         case "ed25519+priv":
             return try CreateEd25519KeyPairOperation(logger: Self.logger)
                 .compute(
                     identifier: key.identifier,
-                    fromPrivateKey: key.storableData
+                    fromPrivateKey: key.storableData,
+                    derivationPath: derivationPath
                 )
         default:
             throw ApolloError.restoratonFailedNoIdentifierOrInvalid
@@ -65,26 +76,37 @@ extension ApolloImpl: KeyRestoration {
     }
 
     public func restoreKey(_ key: StorableKey) async throws -> Key {
+        let derivationPath: DerivationPath?
+        if let derivationStr = key.queryDerivationPath {
+            derivationPath = try DerivationPath(string: derivationStr)
+        } else if let index = key.index {
+            derivationPath = DerivationPath(index: index)
+        } else {
+            derivationPath = nil
+        }
         switch key.restorationIdentifier {
         case "secp256k1+priv":
-            guard let index = key.index else {
+            guard let derivationPath else {
                 throw ApolloError.restoratonFailedNoIdentifierOrInvalid
             }
             return Secp256k1PrivateKey(
                 identifier: key.identifier,
-                internalKey: .init(raw: key.storableData.toKotlinByteArray()), derivationPath: DerivationPath(index: index)
+                internalKey: .init(raw: key.storableData.toKotlinByteArray()),
+                derivationPath: derivationPath
             )
         case "x25519+priv":
             return try CreateX25519KeyPairOperation(logger: Self.logger)
                 .compute(
                     identifier: key.identifier,
-                    fromPrivateKey: key.storableData
+                    fromPrivateKey: key.storableData,
+                    derivationPath: derivationPath
                 )
         case "ed25519+priv":
             return try CreateEd25519KeyPairOperation(logger: Self.logger)
                 .compute(
                     identifier: key.identifier,
-                    fromPrivateKey: key.storableData
+                    fromPrivateKey: key.storableData,
+                    derivationPath: derivationPath
                 )
         case "secp256k1+pub":
             return Secp256k1PublicKey(

diff --git a/EdgeAgentSDK/Apollo/Sources/ApolloImpl+Public.swift b/EdgeAgentSDK/Apollo/Sources/ApolloImpl+Public.swift
@@ -60,7 +60,9 @@ extension ApolloImpl: Apollo {
                 if
                     let keyData = parameters[KeyProperties.rawKey.rawValue].flatMap({ Data(base64Encoded: $0) })
                 {
-                    let derivationPath = try parameters[KeyProperties.derivationPath.rawValue].map { try DerivationPath(string: $0) } ?? DerivationPath(index:0)
+                    let derivationPath = try parameters[KeyProperties.derivationPath.rawValue].map {
+                        try DerivationPath(string: $0)
+                    } ?? DerivationPath()
                     return Secp256k1PrivateKey(raw: keyData, derivationPath: derivationPath)
                 } else {
                     guard

diff --git a/EdgeAgentSDK/Apollo/Sources/Model/Ed25519Key.swift b/EdgeAgentSDK/Apollo/Sources/Model/Ed25519Key.swift
@@ -6,19 +6,23 @@ import Foundation
 struct Ed25519PrivateKey: PrivateKey {
     private let internalKey: ApolloLibrary.KMMEdPrivateKey
     let keyType: String = "EC"
-    let keySpecifications: [String : String] = [
-        "curve" : "Ed25519"
-    ]
+    let keySpecifications: [String : String]
+    let derivationPath: Domain.DerivationPath?
     var identifier: String
     var size: Int { raw.count }
     var raw: Data { internalKey.raw.toData() }
 
     init(
         identifier: String = UUID().uuidString,
-        internalKey: ApolloLibrary.KMMEdPrivateKey
+        internalKey: ApolloLibrary.KMMEdPrivateKey,
+        derivationPath: Domain.DerivationPath? = nil
     ) {
         self.identifier = identifier
         self.internalKey = internalKey
+        var keySpecifications = ["curve" : "Ed25519"]
+        derivationPath.map { keySpecifications[KeyProperties.derivationPath.rawValue] = $0.keyPathString() }
+        self.keySpecifications = keySpecifications
+        self.derivationPath = derivationPath
     }
 
     func publicKey() -> PublicKey {
@@ -46,6 +50,7 @@ extension Ed25519PrivateKey: KeychainStorableKey {
     var restorationIdentifier: String { "ed25519+priv" }
     var storableData: Data { raw }
     var index: Int? { nil }
+    var queryDerivationPath: String? { derivationPath?.keyPathString() }
     var type: Domain.KeychainStorableKeyProperties.KeyAlgorithm { .rawKey }
     var keyClass: Domain.KeychainStorableKeyProperties.KeyType { .privateKey }
     var accessiblity: Domain.KeychainStorableKeyProperties.Accessability? { .firstUnlock(deviceOnly: true) }
@@ -83,6 +88,7 @@ extension Ed25519PublicKey: KeychainStorableKey {
     var restorationIdentifier: String { "ed25519+pub" }
     var storableData: Data { raw }
     var index: Int? { nil }
+    var queryDerivationPath: String? { nil }
     var type: Domain.KeychainStorableKeyProperties.KeyAlgorithm { .rawKey }
     var keyClass: Domain.KeychainStorableKeyProperties.KeyType { .publicKey }
     var accessiblity: Domain.KeychainStorableKeyProperties.Accessability? { .firstUnlock(deviceOnly: true) }

diff --git a/EdgeAgentSDK/Apollo/Sources/Model/LinkSecret.swift b/EdgeAgentSDK/Apollo/Sources/Model/LinkSecret.swift
@@ -41,6 +41,7 @@ extension LinkSecret: KeychainStorableKey {
     var restorationIdentifier: String { "linkSecret+key" }
     var storableData: Data { raw }
     var index: Int? { nil }
+    var queryDerivationPath: String? { nil }
     var type: Domain.KeychainStorableKeyProperties.KeyAlgorithm { .rawKey }
     var keyClass: Domain.KeychainStorableKeyProperties.KeyType { .privateKey }
     var accessiblity: Domain.KeychainStorableKeyProperties.Accessability? { .firstUnlock(deviceOnly: true) }

diff --git a/EdgeAgentSDK/Apollo/Sources/Model/Secp256k1Key.swift b/EdgeAgentSDK/Apollo/Sources/Model/Secp256k1Key.swift
@@ -57,6 +57,7 @@ extension Secp256k1PrivateKey: KeychainStorableKey {
     var restorationIdentifier: String { "secp256k1+priv" }
     var storableData: Data { raw }
     var index: Int? { derivationPath.index }
+    var queryDerivationPath: String? { derivationPath.keyPathString() }
     var type: Domain.KeychainStorableKeyProperties.KeyAlgorithm { .rawKey }
     var keyClass: Domain.KeychainStorableKeyProperties.KeyType { .privateKey }
     var accessiblity: Domain.KeychainStorableKeyProperties.Accessability? { .firstUnlock(deviceOnly: true) }
@@ -112,6 +113,7 @@ extension Secp256k1PublicKey: KeychainStorableKey {
     var restorationIdentifier: String { "secp256k1+pub" }
     var storableData: Data { raw }
     var index: Int? { nil }
+    var queryDerivationPath: String? { nil }
     var type: Domain.KeychainStorableKeyProperties.KeyAlgorithm { .rawKey }
     var keyClass: Domain.KeychainStorableKeyProperties.KeyType { .publicKey }
     var accessiblity: Domain.KeychainStorableKeyProperties.Accessability? { .firstUnlock(deviceOnly: true) }

diff --git a/EdgeAgentSDK/Apollo/Sources/Model/X25519Key.swift b/EdgeAgentSDK/Apollo/Sources/Model/X25519Key.swift
@@ -5,19 +5,23 @@ import Foundation
 struct X25519PrivateKey: PrivateKey {
     private let internalKey: ApolloLibrary.KMMX25519PrivateKey
     let keyType: String = "EC"
-    let keySpecifications: [String : String] = [
-        "curve" : "x25519"
-    ]
+    let keySpecifications: [String : String]
+    let derivationPath: Domain.DerivationPath?
     var identifier:String
     var size: Int { raw.count }
     var raw: Data { internalKey.raw.toData() }
 
     init(
         identifier: String = UUID().uuidString,
-        internalKey: ApolloLibrary.KMMX25519PrivateKey
+        internalKey: ApolloLibrary.KMMX25519PrivateKey,
+        derivationPath: Domain.DerivationPath? = nil
     ) {
         self.identifier = identifier
         self.internalKey = internalKey
+        var keySpecifications = ["curve" : "x25519"]
+        derivationPath.map { keySpecifications[KeyProperties.derivationPath.rawValue] = $0.keyPathString() }
+        self.keySpecifications = keySpecifications
+        self.derivationPath = derivationPath
     }
 
     func publicKey() -> PublicKey {
@@ -34,6 +38,7 @@ extension X25519PrivateKey: KeychainStorableKey {
     var restorationIdentifier: String { "x25519+priv" }
     var storableData: Data { raw }
     var index: Int? { nil }
+    var queryDerivationPath: String? { derivationPath?.keyPathString() }
     var type: Domain.KeychainStorableKeyProperties.KeyAlgorithm { .rawKey }
     var keyClass: Domain.KeychainStorableKeyProperties.KeyType { .privateKey }
     var accessiblity: Domain.KeychainStorableKeyProperties.Accessability? { .firstUnlock(deviceOnly: true) }
@@ -71,6 +76,7 @@ extension X25519PublicKey: KeychainStorableKey {
     var restorationIdentifier: String { "x25519+pub" }
     var storableData: Data { raw }
     var index: Int? { nil }
+    var queryDerivationPath: String? { nil }
     var type: Domain.KeychainStorableKeyProperties.KeyAlgorithm { .rawKey }
     var keyClass: Domain.KeychainStorableKeyProperties.KeyType { .publicKey }
     var accessiblity: Domain.KeychainStorableKeyProperties.Accessability? { .firstUnlock(deviceOnly: true) }

diff --git a/EdgeAgentSDK/Apollo/Sources/Operations/CreateEd25519KeyPairOperation.swift b/EdgeAgentSDK/Apollo/Sources/Operations/CreateEd25519KeyPairOperation.swift
@@ -12,10 +12,15 @@ struct CreateEd25519KeyPairOperation {
 
     }
 
-    func compute(identifier: String = UUID().uuidString, fromPrivateKey: Data) throws -> PrivateKey {
+    func compute(
+        identifier: String = UUID().uuidString,
+        fromPrivateKey: Data,
+        derivationPath: Domain.DerivationPath? = nil
+    ) throws -> PrivateKey {
         return Ed25519PrivateKey(
             identifier: identifier,
-            internalKey: KMMEdPrivateKey(raw: fromPrivateKey.toKotlinByteArray())
+            internalKey: KMMEdPrivateKey(raw: fromPrivateKey.toKotlinByteArray()),
+            derivationPath: derivationPath
         )
     }
 
@@ -27,6 +32,9 @@ struct CreateEd25519KeyPairOperation {
             .derive(path: keyPath.keyPathString()
         )
 
-        return Ed25519PrivateKey(internalKey: .init(raw: derivedHdKey.privateKey))
+        return Ed25519PrivateKey(
+            internalKey: .init(raw: derivedHdKey.privateKey),
+            derivationPath: keyPath
+        )
     }
 }
diff --git a/EdgeAgentSDK/Apollo/Sources/Operations/CreateX25519KeyPairOperation.swift b/EdgeAgentSDK/Apollo/Sources/Operations/CreateX25519KeyPairOperation.swift
@@ -13,11 +13,16 @@ struct CreateX25519KeyPairOperation {
 
     }
 
-    func compute(identifier: String = UUID().uuidString, fromPrivateKey: Data) throws -> PrivateKey {
+    func compute(
+        identifier: String = UUID().uuidString,
+        fromPrivateKey: Data,
+        derivationPath: Domain.DerivationPath? = nil
+    ) throws -> PrivateKey {
         let privateKey = KMMX25519PrivateKey(raw: fromPrivateKey.toKotlinByteArray())
         return X25519PrivateKey(
             identifier: identifier,
-            internalKey: privateKey
+            internalKey: privateKey,
+            derivationPath: derivationPath
         )
     }
 
@@ -29,6 +34,9 @@ struct CreateX25519KeyPairOperation {
             .derive(path: keyPath.keyPathString()
         )
 
-        return X25519PrivateKey(internalKey: KMMEdPrivateKey(raw: derivedHdKey.privateKey).x25519PrivateKey())
+        return X25519PrivateKey(
+            internalKey: KMMEdPrivateKey(raw: derivedHdKey.privateKey).x25519PrivateKey(),
+            derivationPath: keyPath
+        )
     }
 }
diff --git a/EdgeAgentSDK/Castor/Tests/PrismDIDPublicKeyTests.swift b/EdgeAgentSDK/Castor/Tests/PrismDIDPublicKeyTests.swift
@@ -16,7 +16,7 @@ final class PrismDIDPublicKeyTests: XCTestCase {
             KeyProperties.type.rawValue: "EC",
             KeyProperties.curve.rawValue: KnownKeyCurves.secp256k1.rawValue,
             KeyProperties.seed.rawValue: seed.value.base64Encoded(),
-            KeyProperties.derivationPath.rawValue: DerivationPath(index: 0).keyPathString()
+            KeyProperties.derivationPath.rawValue: DerivationPath().keyPathString()
         ])
     }
 

diff --git a/EdgeAgentSDK/Domain/Sources/Models/KeyManagement/DerivableKey.swift b/EdgeAgentSDK/Domain/Sources/Models/KeyManagement/DerivableKey.swift
@@ -2,13 +2,60 @@ import Foundation
 
 /// `DerivationPath` is a structure that represents the path for key derivation in hierarchical deterministic (HD) wallets.
 public struct DerivationPath {
+
+    public enum Axis: RawRepresentable {
+        case normal(Int)
+        case hardened(Int)
+
+        public init?(rawValue: Int) {
+            if rawValue < 0 {
+                return nil
+            }
+            if rawValue >= 0 && rawValue < (1 << 31) {
+                self = .normal(rawValue)
+            } else if rawValue >= (1 << 31) && rawValue < (1 << 32) {
+                self = .hardened(rawValue - (1 << 31))
+            } else {
+                return nil
+            }
+        }
+
+        public var rawValue: Int {
+            switch self {
+            case .normal(let int):
+                return int
+            case .hardened(let int):
+                return int
+            }
+        }
+
+        public var string: String {
+            switch self {
+            case .normal(let int):
+                return "\(int)"
+            case .hardened(let int):
+                return "\(int)'"
+            }
+        }
+    }
+
     /// The index of the key in the path.
+    @available(*, deprecated, renamed: "axis", message: "Use axis instead this property will be removed on a future version")
     public let index: Int
 
+    public let axis: [Axis]
+
     /// Creates a new `DerivationPath` instance from a given index.
     /// - Parameter index: The index of the key in the path.
+    @available(*, deprecated, renamed: "init(axis:)", message: "Use init(axis:) instead this method will be removed on a future version")
     public init(index: Int) {
         self.index = index
+        self.axis = [.hardened(index), .hardened(0), .hardened(0)]
+    }
+
+    public init(axis: [Axis] = [.hardened(0), .hardened(0), .hardened(0)]) {
+        self.axis = axis
+        self.index = axis.first?.rawValue ?? 0
     }
 
     /// Creates a new `DerivationPath` instance from a path string.
@@ -26,16 +73,29 @@ public struct DerivationPath {
         let parsingRegex = try NSRegularExpression(pattern: "\\d+", options: [])
         let matches = parsingRegex.matches(in: string, options: [], range: NSRange(location: 0, length: string.utf16.count))
 
-        guard let firstMatch = matches.first else { throw CommonError.invalidRegex(regex: pattern, invalid: string) }
+        guard let firstMatch = matches.first else {
+            throw CommonError.invalidRegex(regex: pattern, invalid: string)
+        }
         let range = Range(firstMatch.range, in: string)!
-        guard let index = Int(String(string[range])) else { throw CommonError.invalidRegex(regex: pattern, invalid: string) }
+        guard let index = Int(String(string[range])) else {
+            throw CommonError.invalidRegex(regex: pattern, invalid: string)
+        }
         self.index = index
+        self.axis = try matches.map {
+            let range = Range($0.range, in: string)!
+            guard
+                let index = Int(String(string[range]))
+            else {
+                throw CommonError.invalidRegex(regex: pattern, invalid: string)
+            }
+            return Axis.hardened(index)
+        }
     }
 
     /// Returns a string representation of this `DerivationPath`.
     /// - Returns: A string in the format of "m/<index>'/0'/0'".
     public func keyPathString() -> String {
-        return "m/\(index)'/0'/0'"
+        return (["m"] + axis.map(\.string)).joined(separator: "/")
     }
 }
 

diff --git a/EdgeAgentSDK/Domain/Sources/Models/KeyManagement/StorableKey.swift b/EdgeAgentSDK/Domain/Sources/Models/KeyManagement/StorableKey.swift
@@ -12,7 +12,11 @@ public protocol StorableKey {
     var storableData: Data { get }
 
     /// Indexation of the key is useful to keep track of a derivation index
+    @available(*, deprecated, renamed: "derivationPath", message: "Use derivationPath instead this property will be removed on a future version")
     var index: Int? { get }
+
+    /// Derivation path used for this key is useful to keep track of a derivation index
+    var queryDerivationPath: String? { get }
 }
 
 /// Extension of the `Key` protocol to provide additional functionality related to storage.