Add support for ed25519

crypto/src/androidTest/java/com/kunzisoft/asymmetric/SignatureTest.kt

@@ -1,12 +1,19 @@
 package com.kunzisoft.asymmetric
 
+import org.bouncycastle.jcajce.provider.asymmetric.edec.BCEdDSAPrivateKey
+import org.bouncycastle.jcajce.provider.asymmetric.edec.BCXDHPrivateKey
 import org.junit.Test
+import java.io.File
+import java.io.FileWriter
+import kotlin.io.path.Path
 
 class SignatureTest {
 
     // All private keys are for testing only.
     // DO NOT USE THEM
 
+
+    // region ES256
     private val es256PemInKeePassXC =
         """
             -----BEGIN PRIVATE KEY-----
@@ -52,6 +59,10 @@ class SignatureTest {
 
     }
 
+    // endregion
+
+    // region RSA
+
     private val rsa256PemIn = """
         -----BEGIN PRIVATE KEY-----
         MIIEvAIBADANBgkqhkiG9w0BAQEFAASCBKYwggSiAgEAAoIBAQCaunVJEhLHl7/f
@@ -99,4 +110,58 @@ class SignatureTest {
         assert(keyTypeId == Signature.RS256_ALGORITHM)
         assert(privateKeyPem.contains("-----BEGIN PRIVATE KEY-----", true))
     }
+    // endregion
+
+    // region ED25519
+
+    private val ed25519PemInShort = """
+        -----BEGIN PRIVATE KEY-----
+        MC4CAQAwBQYDK2VwBCIEILBoCo4+IXxIuwN36/oaEsPgbe6WYJcV9YW+xnprDF4H
+        -----END PRIVATE KEY-----
+    """.trimIndent()
+
+    private val ed25519PemInLong =  """
+        -----BEGIN PRIVATE KEY-----
+        MFECAQEwBQYDK2VwBCIEIESP8edVGbqoR/pKNmy7j7FV8Y68zrIi/5VEuAJ281K6
+        gSEAyJU1wQNaJUeyxPcWjN7xZKZUhCRoIFS/MQvbdd4QE7Q=
+        -----END PRIVATE KEY-----
+    """.trimIndent()
+
+    private val ed25519PemOut = """
+        -----BEGIN PRIVATE KEY-----
+        MC4CAQAwBQYDK2VwBCIEIESP8edVGbqoR/pKNmy7j7FV8Y68zrIi/5VEuAJ281K6
+        -----END PRIVATE KEY-----
+    """.trimIndent()
+
+    @Test
+    fun testEd25519KeyConverionShortIn() {
+        val privateKey = Signature.createPrivateKey(ed25519PemInShort)
+        val pemOut = Signature.convertPrivateKeyToPem(privateKey)
+
+        assert(pemOut == ed25519PemInShort)
+    }
+
+    @Test
+    fun testEd25519KeyConverionLongIn() {
+        val privateKey = Signature.createPrivateKey(ed25519PemInLong)
+        val pemOut = Signature.convertPrivateKeyToPem(privateKey)
+
+        assert(pemOut == ed25519PemOut)
+    }
+
+    @Test
+    fun testEd25519KeyGenAndConversion() {
+        val (keyPair, keyTypeId) = Signature.generateKeyPair(listOf(Signature.ED_DSA_ALGORITHM))!!
+        val privateKeyPem = Signature.convertPrivateKeyToPem(keyPair.private)
+
+        assert(keyTypeId == Signature.ED_DSA_ALGORITHM)
+        assert(privateKeyPem.contains("-----BEGIN PRIVATE KEY-----", true))
+        assert(privateKeyPem.contains("-----BEGIN EC PRIVATE KEY-----", true).not())
+    }
+
+
+
+
+    // endregion
+
 }

crypto/src/main/java/com/kunzisoft/asymmetric/Signature.kt

@@ -2,7 +2,11 @@ package com.kunzisoft.asymmetric
 
 import android.util.Log
 import org.bouncycastle.asn1.pkcs.PrivateKeyInfo
+import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters
+import org.bouncycastle.crypto.util.OpenSSHPrivateKeyUtil
 import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey
+import org.bouncycastle.jcajce.provider.asymmetric.edec.BCEdDSAPrivateKey
+import org.bouncycastle.jcajce.provider.asymmetric.edec.BCEdDSAPublicKey
 import org.bouncycastle.jcajce.provider.asymmetric.rsa.BCRSAPublicKey
 import org.bouncycastle.jce.provider.BouncyCastleProvider
 import org.bouncycastle.openssl.PEMParser
@@ -27,6 +31,8 @@ object Signature {
     const val RS256_ALGORITHM: Long = -257
     private const val RS256_KEY_SIZE_IN_BITS = 2048
 
+    const val ED_DSA_ALGORITHM: Long = -8
+
     init {
         Security.removeProvider(BouncyCastleProvider.PROVIDER_NAME)
         Security.addProvider(BouncyCastleProvider())
@@ -39,10 +45,11 @@ object Signature {
             "EC" -> "SHA256withECDSA"
             "ECDSA" -> "SHA256withECDSA"
             "RSA" -> "SHA256withRSA"
+            "Ed25519" -> "Ed25519"
             else -> null
         }
         if (algorithmSignature == null) {
-            Log.e(this::class.java.simpleName, "sign: privateKeyPem has an unknown algorithm")
+            Log.e(this::class.java.simpleName, "sign: the algorithm $algorithmKey is unknown")
             return null
         }
         val sig = Signature.getInstance(algorithmSignature, BouncyCastleProvider.PROVIDER_NAME)
@@ -62,6 +69,13 @@ object Signature {
     }
 
     fun convertPrivateKeyToPem(privateKey: PrivateKey): String {
+        var useV1Info = false
+        if (privateKey is BCEdDSAPrivateKey) {
+            // to generate PEM, which are compatible to KeepassXC
+            useV1Info = true
+        }
+        System.setProperty("org.bouncycastle.pkcs8.v1_info_only", useV1Info.toString().lowercase())
+
         val noOutputEncryption = null
         val pemObjectGenerator = JcaPKCS8Generator(privateKey, noOutputEncryption)
 
@@ -86,13 +100,19 @@ object Signature {
                 keyPairGen.initialize(spec)
                 val keyPair = keyPairGen.genKeyPair()
                 return Pair(keyPair, ES256_ALGORITHM)
-            } else if (typeId == RS256_ALGORITHM) {
 
+            } else if (typeId == RS256_ALGORITHM) {
                 val keyPairGen =
                     KeyPairGenerator.getInstance("RSA", BouncyCastleProvider.PROVIDER_NAME)
                 keyPairGen.initialize(RS256_KEY_SIZE_IN_BITS)
                 val keyPair = keyPairGen.genKeyPair()
                 return Pair(keyPair, RS256_ALGORITHM)
+
+            } else if (typeId == ED_DSA_ALGORITHM) {
+                val keyPairGen =
+                    KeyPairGenerator.getInstance("Ed25519", BouncyCastleProvider.PROVIDER_NAME)
+                val keyPair = keyPairGen.genKeyPair()
+                return Pair(keyPair, ED_DSA_ALGORITHM)
             }
         }
 
@@ -108,12 +128,19 @@ object Signature {
             }
         } else if (keyTypeId == RS256_ALGORITHM) {
             return publicKeyIn.encoded
+        } else if (keyTypeId == ED_DSA_ALGORITHM) {
+            return publicKeyIn.encoded
         }
         Log.e(this::class.java.simpleName, "convertPublicKey: unknown key type id found")
         return null
     }
 
     fun convertPublicKeyToMap(publicKeyIn: PublicKey, keyTypeId: Long): Map<Int, Any>? {
+
+        // https://www.iana.org/assignments/cose/cose.xhtml#key-common-parameters
+        val keyTypeLabel = 1
+        val algorithmLabel = 3
+
         if (keyTypeId == ES256_ALGORITHM) {
             if (publicKeyIn !is BCECPublicKey) {
                 Log.e(
@@ -128,8 +155,9 @@ object Signature {
             val es256KeyTypeId = 2
             val es256EllipticCurveP256Id = 1
 
-            publicKeyMap[1] = es256KeyTypeId
-            publicKeyMap[3] = ES256_ALGORITHM
+            publicKeyMap[keyTypeLabel] = es256KeyTypeId
+            publicKeyMap[algorithmLabel] = ES256_ALGORITHM
+
             publicKeyMap[-1] = es256EllipticCurveP256Id
 
             val ecPoint = publicKeyIn.q
@@ -154,8 +182,8 @@ object Signature {
             val rs256ExponentSizeInBytes = 3
 
             val publicKeyMap = mutableMapOf<Int, Any>()
-            publicKeyMap[1] = rs256KeyTypeId
-            publicKeyMap[3] = RS256_ALGORITHM
+            publicKeyMap[keyTypeLabel] = rs256KeyTypeId
+            publicKeyMap[algorithmLabel] = RS256_ALGORITHM
             publicKeyMap[-1] =
                 BigIntegers.asUnsignedByteArray(rs256KeySizeInBytes, publicKeyIn.modulus)
             publicKeyMap[-2] =
@@ -164,6 +192,36 @@ object Signature {
                     publicKeyIn.publicExponent
                 )
             return publicKeyMap
+        } else if (keyTypeId == ED_DSA_ALGORITHM) {
+            if (publicKeyIn !is BCEdDSAPublicKey) {
+                Log.e(
+                    this::class.java.simpleName,
+                    "publicKey object has wrong type for keyTypeId $ED_DSA_ALGORITHM: ${publicKeyIn.javaClass.canonicalName}"
+                )
+                return null
+            }
+
+            val publicKeyMap = mutableMapOf<Int, Any>()
+
+            // https://www.rfc-editor.org/rfc/rfc9053#name-key-object-parameters
+            val octetKeyPairId = 1
+
+            val curveLabel = -1
+            val ed25519CurveId = 6
+
+            val publicKeyLabel = -2
+
+            publicKeyMap[keyTypeLabel] = octetKeyPairId
+            publicKeyMap[algorithmLabel] = ED_DSA_ALGORITHM
+
+            publicKeyMap[curveLabel] = ed25519CurveId
+
+            val length = Ed25519PublicKeyParameters.KEY_SIZE
+
+            publicKeyMap[publicKeyLabel] = BigIntegers.asUnsignedByteArray(length,
+                BigIntegers.fromUnsignedByteArray(publicKeyIn.pointEncoding))
+
+            return publicKeyMap
         }
 
         Log.e(this::class.java.simpleName, "convertPublicKeyToMap: no known key type id found")