feat(agent): implement issue credential protocol

Fixes ATL-2499

.swiftlint.yml

@@ -71,6 +71,7 @@ opt_in_rules:
   - xct_specific_matcher
   - yoda_condition
 excluded:
+  - .build
   - build
   - Pods
   - protobuf

Castor/Sources/Helpers/Base64+DIDMethodID.swift

@@ -3,28 +3,10 @@ import Foundation
 
 extension Base64Utils {
     func encodeMethodID(data: Data) -> String {
-        encode(data)
-            .replacingOccurrences(of: "/", with: "_")
-            .replacingOccurrences(of: "+", with: "-")
-            .trimingTrailing(while: CharacterSet(charactersIn: "="))
+        data.base64UrlEncodedString()
     }
 
     func decodeMethodID(str: String) -> Data? {
-        let expectedLength = (str.count + 3) / 4 * 4
-        return decode(str
-            .replacingOccurrences(of: "_", with: "/")
-            .replacingOccurrences(of: "-", with: "+")
-            .appending(String(repeating: .init("="), count: expectedLength))
-        )
-    }
-}
-
-private extension String {
-    func trimingTrailing(while characterSet: CharacterSet) -> String {
-        guard
-            let index = lastIndex(where: { !CharacterSet(charactersIn: String($0)).isSubset(of: characterSet) })
-        else { return self }
-
-        return String(self[...index])
+        return Data(fromBase64URL: str)
     }
 }

Core/Sources/Helpers/Base64Utils.swift

@@ -0,0 +1,44 @@
+import Foundation
+
+public struct Base64Utils {
+    public init() {}
+
+    public func encode(_ data: Data) -> String {
+        String(data.base64EncodedString()
+            .replacingOccurrences(of: "/", with: "_")
+            .replacingOccurrences(of: "+", with: "-")
+            .trimingTrailing(while: CharacterSet(charactersIn: "=")))
+    }
+
+    public func decode(_ src: String) -> Data? {
+        let expectedLength = (src.count + 3) / 4 * 4
+        let base64Encoded = src
+            .replacingOccurrences(of: "_", with: "/")
+            .replacingOccurrences(of: "-", with: "+")
+            .appending(String(repeating: .init("="), count: expectedLength))
+        return Data(base64Encoded: base64Encoded)
+    }
+}
+
+public extension Data {
+    func base64UrlEncodedString() -> String {
+        Base64Utils().encode(self)
+    }
+
+    init?(fromBase64URL: String) {
+        guard let data = Base64Utils().decode(fromBase64URL) else {
+            return nil
+        }
+        self = data
+    }
+}
+
+private extension String {
+    func trimingTrailing(while characterSet: CharacterSet) -> String {
+        guard
+            let index = lastIndex(where: { !CharacterSet(charactersIn: String($0)).isSubset(of: characterSet) })
+        else { return self }
+
+        return String(self[...index])
+    }
+}

Domain/Sources/Models/MessageAttachment.swift

@@ -60,7 +60,7 @@ public struct AttachmentJsonData: AttachmentData {
 
 public struct AttachmentDescriptor {
     public let id: String
-    public let mediaType: [String]?
+    public let mediaType: String?
     public let data: AttachmentData
     public let filename: [String]?
     public let lastmodTime: Date?
@@ -69,7 +69,7 @@ public struct AttachmentDescriptor {
 
     public init(
         id: String,
-        mediaType: [String]? = nil,
+        mediaType: String? = nil,
         data: AttachmentData,
         filename: [String]? = nil,
         lastmodTime: Date? = nil,

Pluto/Sources/Resources/PrismPluto.xcdatamodeld/.xccurrentversion

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>_XCCurrentVersionName</key>
+	<string>PrismPluto.xcdatamodel</string>
+</dict>
+</plist>

PrismAgent/Sources/Errors.swift

@@ -10,4 +10,8 @@ public enum PrismAgentError: Error {
     case unknownPrismOnboardingTypeError
     case failedToOnboardError
     case invalidPickupDeliveryMessageError
+    case invalidOfferCredentialMessageError
+    case invalidProposedCredentialMessageError
+    case invalidIssueCredentialMessageError
+    case invalidRequestCredentialMessageError
 }

PrismAgent/Sources/Helpers/AttachmentDescriptor+Builder.swift

@@ -0,0 +1,18 @@
+import Core
+import Domain
+import Foundation
+
+extension AttachmentDescriptor {
+    static func build<T: Encodable>(
+        id: String = UUID().uuidString,
+        payload: T,
+        mediaType: String? = "application/json"
+    ) throws -> AttachmentDescriptor {
+        let encoded = try JSONEncoder().encode(payload).base64UrlEncodedString()
+        return AttachmentDescriptor(
+            id: id,
+            mediaType: mediaType,
+            data: AttachmentBase64(base64: encoded)
+        )
+    }
+}

PrismAgent/Sources/Protocols/IssueCredential/CredentialPreview.swift

@@ -0,0 +1,30 @@
+import Domain
+import Foundation
+
+// https://github.com/hyperledger/aries-rfcs/tree/main/features/0453-issue-credential-v2#preview-credential
+public struct CredentialPreview: Codable, Equatable {
+    public struct Attribute: Codable, Equatable {
+        public let name: String
+        public let value: String
+        public let mimeType: String?
+    }
+
+    public let type: String
+    public let attributes: [Attribute]
+
+    public init(attributes: [Attribute]) {
+        self.type = ProtocolTypes.didcommCredentialPreview.rawValue
+        self.attributes = attributes
+    }
+}
+
+struct CredentialFormat: Codable, Equatable {
+//    know Format:
+//     https://github.com/hyperledger/aries-rfcs/tree/main/features/0453-issue-credential-v2#propose-attachment-registry
+//    - dif/[email protected]
+//    - aries/[email protected]
+//    - hlindy/[email protected]
+//    
+    let attachId: String
+    let format: String
+}

PrismAgent/Sources/Protocols/IssueCredential/IssueCredential.swift

@@ -0,0 +1,134 @@
+import Domain
+import Foundation
+
+// ALL parameters are DIDCOMMV2 format and naming conventions and follows the protocol
+// https://github.com/hyperledger/aries-rfcs/tree/main/features/0453-issue-credential-v2
+public struct IssueCredential {
+    struct Body: Codable, Equatable {
+        let goalCode: String?
+        let comment: String?
+        let replacementId: String?
+        let moreAvailable: String?
+        let formats: [CredentialFormat]
+
+        init(
+            goalCode: String? = nil,
+            comment: String? = nil,
+            replacementId: String? = nil,
+            moreAvailable: String? = nil,
+            formats: [CredentialFormat]
+        ) {
+            self.goalCode = goalCode
+            self.comment = comment
+            self.replacementId = replacementId
+            self.moreAvailable = moreAvailable
+            self.formats = formats
+        }
+    }
+
+    public let id: String
+    public let type = ProtocolTypes.didcommIssueCredential.rawValue
+    let body: Body
+    let attachments: [AttachmentDescriptor]
+    public let thid: String?
+    public let from: DID
+    // swiftlint:disable identifier_name
+    public let to: DID
+    // swiftlint:enable identifier_name
+
+    init(
+        id: String = UUID().uuidString,
+        body: Body,
+        attachments: [AttachmentDescriptor],
+        thid: String?,
+        from: DID,
+        // swiftlint:disable identifier_name
+        to: DID
+        // swiftlint:enable identifier_name
+    ) {
+        self.id = id
+        self.body = body
+        self.attachments = attachments
+        self.thid = thid
+        self.from = from
+        self.to = to
+    }
+
+    public init(fromMessage: Message) throws {
+        guard
+            fromMessage.piuri == ProtocolTypes.didcommIssueCredential.rawValue,
+            let fromDID = fromMessage.from,
+            let toDID = fromMessage.to
+        else { throw PrismAgentError.invalidIssueCredentialMessageError }
+
+        let body = try JSONDecoder().decode(Body.self, from: fromMessage.body)
+        self.init(
+            id: fromMessage.id,
+            body: body,
+            attachments: fromMessage.attachments,
+            thid: fromMessage.thid,
+            from: fromDID,
+            to: toDID
+        )
+    }
+
+    public func makeMessage() throws -> Message {
+        .init(
+            id: id,
+            piuri: type,
+            from: from,
+            to: to,
+            body: try JSONEncoder().encode(body),
+            attachments: attachments,
+            thid: thid
+        )
+    }
+
+    public static func makeIssueFromRequestCredential(msg: Message) throws -> IssueCredential {
+        let request = try RequestCredential(fromMessage: msg)
+
+        return IssueCredential(
+            body: Body(
+                goalCode: request.body.goalCode,
+                comment: request.body.comment,
+                formats: request.body.formats
+            ),
+            attachments: request.attachments,
+            thid: msg.id,
+            from: request.to,
+            to: request.from)
+    }
+
+    static func build<T: Encodable>(
+        fromDID: DID,
+        toDID: DID,
+        thid: String?,
+        credentialPreview: CredentialPreview,
+        credentials: [String: T] = [:]
+    ) throws -> IssueCredential {
+        let aux = try credentials.map { key, value in
+            let attachment = try AttachmentDescriptor.build(payload: value)
+            let format = CredentialFormat(attachId: attachment.id, format: key)
+            return (format, attachment)
+        }
+        return IssueCredential(
+            body: Body(
+                formats: aux.map { $0.0 }
+            ),
+            attachments: aux.map { $0.1 },
+            thid: thid,
+            from: fromDID,
+            to: toDID
+        )
+    }
+}
+
+extension IssueCredential: Equatable {
+    public static func == (lhs: IssueCredential, rhs: IssueCredential) -> Bool {
+        lhs.id == rhs.id &&
+        lhs.type == rhs.type &&
+        lhs.from == rhs.from &&
+        lhs.to == rhs.to &&
+        lhs.body == rhs.body
+    }
+}