Messily fix RSA

Sources/Packages/Sources/SecretAgentKit/Agent.swift

@@ -135,47 +135,44 @@ extension Agent {
         }
 
         let dataToSign = reader.readNextChunk()
-        let signed = try await store.sign(data: dataToSign, with: secret, for: provenance)
-        let derSignature = signed
+        let rawRepresentation = try await store.sign(data: dataToSign, with: secret, for: provenance)
 
         let curveData = Data(writer.curveType(for: secret.keyType).utf8)
 
-        // Convert from DER formatted rep to raw (r||s)
+        let signedData: Data
+        if secret.keyType.algorithm == .ecdsa {
+            let rawLength = rawRepresentation.count/2
+            // Check if we need to pad with 0x00 to prevent certain
+            // ssh servers from thinking r or s is negative
+            let paddingRange: ClosedRange<UInt8> = 0x80...0xFF
+            var r = Data(rawRepresentation[0..<rawLength])
+            if paddingRange ~= r.first! {
+                r.insert(0x00, at: 0)
+            }
+            var s = Data(rawRepresentation[rawLength...])
+            if paddingRange ~= s.first! {
+                s.insert(0x00, at: 0)
+            }
 
-        let rawRepresentation: Data
-        switch (secret.keyType.algorithm, secret.keyType.size) {
-        case (.ecdsa, 256):
-            rawRepresentation = try CryptoKit.P256.Signing.ECDSASignature(derRepresentation: derSignature).rawRepresentation
-        case (.ecdsa, 384):
-            rawRepresentation = try CryptoKit.P384.Signing.ECDSASignature(derRepresentation: derSignature).rawRepresentation
-        default:
-            throw AgentError.unsupportedKeyType
+            var signatureChunk = Data()
+            signatureChunk.append(writer.lengthAndData(of: r))
+            signatureChunk.append(writer.lengthAndData(of: s))
+            var mutSignedData = Data()
+            var sub = Data()
+            sub.append(writer.lengthAndData(of: curveData))
+            sub.append(writer.lengthAndData(of: signatureChunk))
+            mutSignedData.append(writer.lengthAndData(of: sub))
+            signedData = mutSignedData
+        } else {
+            var mutSignedData = Data()
+            var sub = Data()
+            sub.append(writer.lengthAndData(of: Data("rsa-sha2-512".utf8)))
+            sub.append(writer.lengthAndData(of: rawRepresentation))
+            mutSignedData.append(writer.lengthAndData(of: sub))
+
+            signedData = mutSignedData
         }
 
-
-        let rawLength = rawRepresentation.count/2
-        // Check if we need to pad with 0x00 to prevent certain
-        // ssh servers from thinking r or s is negative
-        let paddingRange: ClosedRange<UInt8> = 0x80...0xFF
-        var r = Data(rawRepresentation[0..<rawLength])
-        if paddingRange ~= r.first! {
-            r.insert(0x00, at: 0)
-        }
-        var s = Data(rawRepresentation[rawLength...])
-        if paddingRange ~= s.first! {
-            s.insert(0x00, at: 0)
-        }
-
-        var signatureChunk = Data()
-        signatureChunk.append(writer.lengthAndData(of: r))
-        signatureChunk.append(writer.lengthAndData(of: s))
-
-        var signedData = Data()
-        var sub = Data()
-        sub.append(writer.lengthAndData(of: curveData))
-        sub.append(writer.lengthAndData(of: signatureChunk))
-        signedData.append(writer.lengthAndData(of: sub))
-
         if let witness = witness {
             try await witness.witness(accessTo: secret, from: store, by: provenance)
         }

Sources/Packages/Sources/SecretKit/KeychainTypes.swift

@@ -51,16 +51,14 @@ public extension SecretStore {
     /// Returns the appropriate keychian signature algorithm to use for a given secret.
     /// - Parameters:
     ///   - secret: The secret which will be used for signing.
-    ///   - allowRSA: Whether or not RSA key types should be permited.
     /// - Returns: The appropriate algorithm.
-    func signatureAlgorithm(for secret: SecretType, allowRSA: Bool = false) -> SecKeyAlgorithm {
+    func signatureAlgorithm(for secret: SecretType) -> SecKeyAlgorithm {
         switch (secret.keyType.algorithm, secret.keyType.size) {
         case (.ecdsa, 256):
             return .ecdsaSignatureMessageX962SHA256
         case (.ecdsa, 384):
             return .ecdsaSignatureMessageX962SHA384
         case (.rsa, 1024), (.rsa, 2048):
-            guard allowRSA else { fatalError() }
             return .rsaSignatureMessagePKCS1v15SHA512
         default:
             fatalError()

Sources/Packages/Sources/SecretKit/OpenSSH/OpenSSHKeyWriter.swift

@@ -104,9 +104,8 @@ extension OpenSSHKeyWriter {
             "nistp" + String(describing: keyType.size)
         case .mldsa:
             "mldsa" + String(describing: keyType.size)
-        case .rsa:
-            // All RSA keys use the same 512 bit hash function
-            "rsa-sha2-512"
+        default:
+            fatalError()
         }
     }
 

Sources/Packages/Sources/SecureEnclaveSecretKit/SecureEnclaveStore.swift

@@ -69,7 +69,7 @@ extension SecureEnclave {
             switch (attributes.keyType.algorithm, attributes.keyType.size) {
             case (.ecdsa, 256):
                 let key = try CryptoKit.SecureEnclave.P256.Signing.PrivateKey(dataRepresentation: keyData)
-                return try key.signature(for: data).derRepresentation
+                return try key.signature(for: data).rawRepresentation
             case (.mldsa, 65):
                 guard #available(macOS 26.0, *)  else { throw UnsupportedAlgorithmError() }
                 let key = try CryptoKit.SecureEnclave.MLDSA65.PrivateKey(dataRepresentation: keyData)

Sources/Packages/Sources/SmartCardSecretKit/SmartCardStore.swift

@@ -79,7 +79,7 @@ extension SmartCard {
             }
             let key = untypedSafe as! SecKey
             var signError: SecurityError?
-            guard let signature = SecKeyCreateSignature(key, signatureAlgorithm(for: secret, allowRSA: true), data as CFData, &signError) else {
+            guard let signature = SecKeyCreateSignature(key, signatureAlgorithm(for: secret), data as CFData, &signError) else {
                 throw SigningError(error: signError)
             }
             return signature as Data