Release 0.12.0 (#95)

* Check arguments passed to secp256k1 methods

Illegal arguments will trigger an internal callback that prints to stderr and calls abort.
We already check arguments in our JNI and kotlin native code but had missed 2 checks (recid in ecdsaRecover, empty arrays in pubkeyCombine).

* Implement the same "tweak" checks in the native code and JNI code

The native code was missing checks on the "tweak" size (which must be 32 bytes)

build.gradle.kts

@@ -22,7 +22,7 @@ buildscript {
 
 allprojects {
     group = "fr.acinq.secp256k1"
-    version = "0.12.0-SNAPSHOT"
+    version = "0.12.0"
 
     repositories {
         google()

src/commonMain/kotlin/fr/acinq/secp256k1/Secp256k1.kt

@@ -166,17 +166,7 @@ public interface Secp256k1 {
 
 internal expect fun getSecpk256k1(): Secp256k1
 
-public open class Secp256k1Exception : RuntimeException {
-    public constructor() : super()
-    public constructor(message: String?) : super(message)
-}
-
-public class Secp256k1ErrorCallbackException : Secp256k1Exception {
-    public constructor() : super()
-    public constructor(message: String?) : super(message)
-}
-
-public class Secp256k1IllegalCallbackException : Secp256k1Exception {
+public class Secp256k1Exception : RuntimeException {
     public constructor() : super()
     public constructor(message: String?) : super(message)
 }

src/nativeMain/kotlin/fr/acinq/secp256k1/Secp256k1Native.kt

@@ -4,67 +4,15 @@ import kotlinx.cinterop.*
 import platform.posix.size_tVar
 import secp256k1.*
 
-private typealias Secp256k1CallbackHandler = (String) -> Unit
-
-@OptIn(ExperimentalStdlibApi::class)
-private class CallbackHandler(ctx: CPointer<secp256k1_context>) : AutoCloseable {
-    var illegalCallBackMessage: String? = null
-    val illegalHandler: Secp256k1CallbackHandler = { x: String -> illegalCallBackMessage = x }
-    val illegalCallbackRef = StableRef.create(illegalHandler)
-    var errorCallBackMessage: String? = null
-    val errorHandler: Secp256k1CallbackHandler = { x: String -> errorCallBackMessage = x }
-    val errorCallbackRef = StableRef.create(errorHandler)
-
-    init {
-        secp256k1_context_set_error_callback(
-            ctx, staticCFunction { buffer: CPointer<ByteVar>?, data: COpaquePointer? ->
-                if (data != null) {
-                    val callback = data.asStableRef<Secp256k1CallbackHandler>().get()
-                    callback(buffer?.toKString() ?: "error callback triggered")
-                }
-            },
-            errorCallbackRef.asCPointer()
-        )
-        secp256k1_context_set_illegal_callback(
-            ctx, staticCFunction { buffer: CPointer<ByteVar>?, data: COpaquePointer? ->
-                if (data != null) {
-                    val callback = data.asStableRef<Secp256k1CallbackHandler>().get()
-                    callback(buffer?.toKString() ?: "illegal callback triggered")
-                }
-            },
-            illegalCallbackRef.asCPointer()
-        )
-    }
-
-    fun checkForErrors() {
-        errorCallBackMessage?.let { throw Secp256k1ErrorCallbackException(it) }
-        illegalCallBackMessage?.let { throw Secp256k1IllegalCallbackException(it) }
-    }
-
-    override fun close() {
-        // StableRef instances have to be disposed of manually
-        illegalCallbackRef.dispose()
-        errorCallbackRef.dispose()
-    }
-}
-
-@OptIn(ExperimentalUnsignedTypes::class, ExperimentalStdlibApi::class)
+@OptIn(ExperimentalUnsignedTypes::class)
 public object Secp256k1Native : Secp256k1 {
 
     private val ctx: CPointer<secp256k1_context> by lazy {
-
         secp256k1_context_create((SECP256K1_FLAGS_TYPE_CONTEXT or SECP256K1_FLAGS_BIT_CONTEXT_SIGN or SECP256K1_FLAGS_BIT_CONTEXT_VERIFY).toUInt())
             ?: error("Could not create secp256k1 context")
     }
 
-    private fun Int.requireSuccess(message: String): Int {
-        return if (this != 1) throw Secp256k1Exception(message) else this
-    }
-
-    private fun Int.requireSuccess(callbackHandler: CallbackHandler, message: String): Int {
-        callbackHandler.checkForErrors()
-        return if (this != 1) throw Secp256k1Exception(message) else this
-    }
+    private fun Int.requireSuccess(message: String): Int = if (this != 1) throw Secp256k1Exception(message) else this
 
     private fun MemScope.allocSignature(input: ByteArray): secp256k1_ecdsa_signature {
         val sig = alloc<secp256k1_ecdsa_signature>()
@@ -110,209 +58,173 @@ public object Secp256k1Native : Secp256k1 {
     public override fun verify(signature: ByteArray, message: ByteArray, pubkey: ByteArray): Boolean {
         require(message.size == 32)
         require(pubkey.size == 33 || pubkey.size == 65)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPubkey = allocPublicKey(pubkey)
-                val nMessage = toNat(message)
-                val nSig = allocSignature(signature)
-                val verify = secp256k1_ecdsa_verify(ctx, nSig.ptr, nMessage, nPubkey.ptr)
-                callbackHandler.checkForErrors()
-                return verify == 1
-            }
+        memScoped {
+            val nPubkey = allocPublicKey(pubkey)
+            val nMessage = toNat(message)
+            val nSig = allocSignature(signature)
+            return secp256k1_ecdsa_verify(ctx, nSig.ptr, nMessage, nPubkey.ptr) == 1
         }
     }
 
     public override fun sign(message: ByteArray, privkey: ByteArray): ByteArray {
         require(privkey.size == 32)
         require(message.size == 32)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPrivkey = toNat(privkey)
-                val nMessage = toNat(message)
-                val nSig = alloc<secp256k1_ecdsa_signature>()
-                secp256k1_ecdsa_sign(ctx, nSig.ptr, nMessage, nPrivkey, null, null).requireSuccess(callbackHandler, "secp256k1_ecdsa_sign() failed")
-                return serializeSignature(nSig)
-            }
+        memScoped {
+            val nPrivkey = toNat(privkey)
+            val nMessage = toNat(message)
+            val nSig = alloc<secp256k1_ecdsa_signature>()
+            secp256k1_ecdsa_sign(ctx, nSig.ptr, nMessage, nPrivkey, null, null).requireSuccess("secp256k1_ecdsa_sign() failed")
+            return serializeSignature(nSig)
         }
     }
 
     public override fun signatureNormalize(sig: ByteArray): Pair<ByteArray, Boolean> {
-        require(sig.size >= 64) { "invalid signature ${Hex.encode(sig)}" }
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nSig = allocSignature(sig)
-                val isHighS = secp256k1_ecdsa_signature_normalize(ctx, nSig.ptr, nSig.ptr)
-                callbackHandler.checkForErrors()
-                return Pair(serializeSignature(nSig), isHighS == 1)
-            }
+        require(sig.size >= 64){ "invalid signature ${Hex.encode(sig)}" }
+        memScoped {
+            val nSig = allocSignature(sig)
+            val isHighS = secp256k1_ecdsa_signature_normalize(ctx, nSig.ptr, nSig.ptr)
+            return Pair(serializeSignature(nSig), isHighS == 1)
         }
     }
 
     public override fun secKeyVerify(privkey: ByteArray): Boolean {
         if (privkey.size != 32) return false
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPrivkey = toNat(privkey)
-                val result = secp256k1_ec_seckey_verify(ctx, nPrivkey) == 1
-                callbackHandler.checkForErrors()
-                return result
-            }
+        memScoped {
+            val nPrivkey = toNat(privkey)
+            return secp256k1_ec_seckey_verify(ctx, nPrivkey) == 1
         }
     }
 
     public override fun pubkeyCreate(privkey: ByteArray): ByteArray {
         require(privkey.size == 32)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPrivkey = toNat(privkey)
-                val nPubkey = alloc<secp256k1_pubkey>()
-                secp256k1_ec_pubkey_create(ctx, nPubkey.ptr, nPrivkey).requireSuccess(callbackHandler, "secp256k1_ec_pubkey_create() failed")
-                return serializePubkey(nPubkey)
-            }
+        memScoped {
+            val nPrivkey = toNat(privkey)
+            val nPubkey = alloc<secp256k1_pubkey>()
+            secp256k1_ec_pubkey_create(ctx, nPubkey.ptr, nPrivkey).requireSuccess("secp256k1_ec_pubkey_create() failed")
+            return serializePubkey(nPubkey)
         }
     }
 
     public override fun pubkeyParse(pubkey: ByteArray): ByteArray {
         require(pubkey.size == 33 || pubkey.size == 65)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPubkey = allocPublicKey(pubkey)
-                val result = serializePubkey(nPubkey)
-                callbackHandler.checkForErrors()
-                return result
-            }
+        memScoped {
+            val nPubkey = allocPublicKey(pubkey)
+            return serializePubkey(nPubkey)
         }
     }
 
     public override fun privKeyNegate(privkey: ByteArray): ByteArray {
         require(privkey.size == 32)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val negated = privkey.copyOf()
-                val negPriv = toNat(negated)
-                secp256k1_ec_seckey_negate(ctx, negPriv).requireSuccess(callbackHandler, "secp256k1_ec_seckey_negate() failed")
-                return negated
-            }
+        memScoped {
+            val negated = privkey.copyOf()
+            val negPriv = toNat(negated)
+            secp256k1_ec_seckey_negate(ctx, negPriv).requireSuccess("secp256k1_ec_seckey_negate() failed")
+            return negated
         }
     }
 
     public override fun privKeyTweakAdd(privkey: ByteArray, tweak: ByteArray): ByteArray {
         require(privkey.size == 32)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val added = privkey.copyOf()
-                val natAdd = toNat(added)
-                val natTweak = toNat(tweak)
-                secp256k1_ec_seckey_tweak_add(ctx, natAdd, natTweak).requireSuccess(callbackHandler, "secp256k1_ec_seckey_tweak_add() failed")
-                return added
-            }
+        require(tweak.size == 32)
+        memScoped {
+            val added = privkey.copyOf()
+            val natAdd = toNat(added)
+            val natTweak = toNat(tweak)
+            secp256k1_ec_seckey_tweak_add(ctx, natAdd, natTweak).requireSuccess("secp256k1_ec_seckey_tweak_add() failed")
+            return added
         }
     }
 
     public override fun privKeyTweakMul(privkey: ByteArray, tweak: ByteArray): ByteArray {
         require(privkey.size == 32)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val multiplied = privkey.copyOf()
-                val natMul = toNat(multiplied)
-                val natTweak = toNat(tweak)
-                secp256k1_ec_privkey_tweak_mul(ctx, natMul, natTweak).requireSuccess(callbackHandler, "secp256k1_ec_privkey_tweak_mul() failed")
-                return multiplied
-            }
+        require(tweak.size == 32)
+        memScoped {
+            val multiplied = privkey.copyOf()
+            val natMul = toNat(multiplied)
+            val natTweak = toNat(tweak)
+            secp256k1_ec_privkey_tweak_mul(ctx, natMul, natTweak).requireSuccess("secp256k1_ec_privkey_tweak_mul() failed")
+            return multiplied
         }
     }
 
     public override fun pubKeyNegate(pubkey: ByteArray): ByteArray {
         require(pubkey.size == 33 || pubkey.size == 65)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPubkey = allocPublicKey(pubkey)
-                secp256k1_ec_pubkey_negate(ctx, nPubkey.ptr).requireSuccess(callbackHandler, "secp256k1_ec_pubkey_negate() failed")
-                return serializePubkey(nPubkey)
-            }
+        memScoped {
+            val nPubkey = allocPublicKey(pubkey)
+            secp256k1_ec_pubkey_negate(ctx, nPubkey.ptr).requireSuccess("secp256k1_ec_pubkey_negate() failed")
+            return serializePubkey(nPubkey)
         }
     }
 
     public override fun pubKeyTweakAdd(pubkey: ByteArray, tweak: ByteArray): ByteArray {
         require(pubkey.size == 33 || pubkey.size == 65)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPubkey = allocPublicKey(pubkey)
-                val nTweak = toNat(tweak)
-                secp256k1_ec_pubkey_tweak_add(ctx, nPubkey.ptr, nTweak).requireSuccess(callbackHandler, "secp256k1_ec_pubkey_tweak_add() failed")
-                return serializePubkey(nPubkey)
-            }
+        require(tweak.size == 32)
+        memScoped {
+            val nPubkey = allocPublicKey(pubkey)
+            val nTweak = toNat(tweak)
+            secp256k1_ec_pubkey_tweak_add(ctx, nPubkey.ptr, nTweak).requireSuccess("secp256k1_ec_pubkey_tweak_add() failed")
+            return serializePubkey(nPubkey)
         }
     }
 
     public override fun pubKeyTweakMul(pubkey: ByteArray, tweak: ByteArray): ByteArray {
         require(pubkey.size == 33 || pubkey.size == 65)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPubkey = allocPublicKey(pubkey)
-                val nTweak = toNat(tweak)
-                secp256k1_ec_pubkey_tweak_mul(ctx, nPubkey.ptr, nTweak).requireSuccess(callbackHandler, "secp256k1_ec_pubkey_tweak_mul() failed")
-                return serializePubkey(nPubkey)
-            }
+        require(tweak.size == 32)
+        memScoped {
+            val nPubkey = allocPublicKey(pubkey)
+            val nTweak = toNat(tweak)
+            secp256k1_ec_pubkey_tweak_mul(ctx, nPubkey.ptr, nTweak).requireSuccess("secp256k1_ec_pubkey_tweak_mul() failed")
+            return serializePubkey(nPubkey)
         }
     }
 
     public override fun pubKeyCombine(pubkeys: Array<ByteArray>): ByteArray {
+        require(pubkeys.isNotEmpty())
         pubkeys.forEach { require(it.size == 33 || it.size == 65) }
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPubkeys = pubkeys.map { allocPublicKey(it).ptr }
-                val combined = alloc<secp256k1_pubkey>()
-                secp256k1_ec_pubkey_combine(ctx, combined.ptr, nPubkeys.toCValues(), pubkeys.size.convert()).requireSuccess(callbackHandler, "secp256k1_ec_pubkey_combine() failed")
-                return serializePubkey(combined)
-            }
+        memScoped {
+            val nPubkeys = pubkeys.map { allocPublicKey(it).ptr }
+            val combined = alloc<secp256k1_pubkey>()
+            secp256k1_ec_pubkey_combine(ctx, combined.ptr, nPubkeys.toCValues(), pubkeys.size.convert()).requireSuccess("secp256k1_ec_pubkey_combine() failed")
+            return serializePubkey(combined)
         }
     }
 
     public override fun ecdh(privkey: ByteArray, pubkey: ByteArray): ByteArray {
         require(privkey.size == 32)
         require(pubkey.size == 33 || pubkey.size == 65)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPubkey = allocPublicKey(pubkey)
-                val nPrivkey = toNat(privkey)
-                val output = allocArray<UByteVar>(32)
-                secp256k1_ecdh(ctx, output, nPubkey.ptr, nPrivkey, null, null).requireSuccess(callbackHandler, "secp256k1_ecdh() failed")
-                return output.readBytes(32)
-            }
+        memScoped {
+            val nPubkey = allocPublicKey(pubkey)
+            val nPrivkey = toNat(privkey)
+            val output = allocArray<UByteVar>(32)
+            secp256k1_ecdh(ctx, output, nPubkey.ptr, nPrivkey, null, null).requireSuccess("secp256k1_ecdh() failed")
+            return output.readBytes(32)
         }
     }
 
     public override fun ecdsaRecover(sig: ByteArray, message: ByteArray, recid: Int): ByteArray {
         require(sig.size == 64)
         require(message.size == 32)
-        // we do not check that recid is valid, which should trigger our illegal callback handler to throw a Secp256k1IllegalCallbackException
-        // require(recid in 0..3)
-
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nSig = toNat(sig)
-                val rSig = alloc<secp256k1_ecdsa_recoverable_signature>()
-                secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, rSig.ptr, nSig, recid).requireSuccess(callbackHandler, "secp256k1_ecdsa_recoverable_signature_parse_compact() failed")
-                val nMessage = toNat(message)
-                val pubkey = alloc<secp256k1_pubkey>()
-                secp256k1_ecdsa_recover(ctx, pubkey.ptr, rSig.ptr, nMessage).requireSuccess(callbackHandler, "secp256k1_ecdsa_recover() failed")
-                return serializePubkey(pubkey)
-            }
+        require(recid in 0..3)
+        memScoped {
+            val nSig = toNat(sig)
+            val rSig = alloc<secp256k1_ecdsa_recoverable_signature>()
+            secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, rSig.ptr, nSig, recid).requireSuccess("secp256k1_ecdsa_recoverable_signature_parse_compact() failed")
+            val nMessage = toNat(message)
+            val pubkey = alloc<secp256k1_pubkey>()
+            secp256k1_ecdsa_recover(ctx, pubkey.ptr, rSig.ptr, nMessage).requireSuccess("secp256k1_ecdsa_recover() failed")
+            return serializePubkey(pubkey)
         }
     }
 
     public override fun compact2der(sig: ByteArray): ByteArray {
         require(sig.size == 64)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nSig = allocSignature(sig)
-                val natOutput = allocArray<UByteVar>(73)
-                val len = alloc<size_tVar>()
-                len.value = 73.convert()
-                secp256k1_ecdsa_signature_serialize_der(ctx, natOutput, len.ptr, nSig.ptr).requireSuccess(callbackHandler, "secp256k1_ecdsa_signature_serialize_der() failed")
-                return natOutput.readBytes(len.value.toInt())
-            }
+        memScoped {
+            val nSig = allocSignature(sig)
+            val natOutput = allocArray<UByteVar>(73)
+            val len = alloc<size_tVar>()
+            len.value = 73.convert()
+            secp256k1_ecdsa_signature_serialize_der(ctx, natOutput, len.ptr, nSig.ptr).requireSuccess("secp256k1_ecdsa_signature_serialize_der() failed")
+            return natOutput.readBytes(len.value.toInt())
         }
     }
 
@@ -320,15 +232,13 @@ public object Secp256k1Native : Secp256k1 {
         require(signature.size == 64)
         require(data.size == 32)
         require(pub.size == 32)
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nPub = toNat(pub)
-                val pubkey = alloc<secp256k1_xonly_pubkey>()
-                secp256k1_xonly_pubkey_parse(ctx, pubkey.ptr, nPub).requireSuccess(callbackHandler, "secp256k1_xonly_pubkey_parse() failed")
-                val nData = toNat(data)
-                val nSig = toNat(signature)
-                return secp256k1_schnorrsig_verify(ctx, nSig, nData, 32u, pubkey.ptr) == 1
-            }
+        memScoped {
+            val nPub = toNat(pub)
+            val pubkey = alloc<secp256k1_xonly_pubkey>()
+            secp256k1_xonly_pubkey_parse(ctx, pubkey.ptr, nPub).requireSuccess("secp256k1_xonly_pubkey_parse() failed")
+            val nData = toNat(data)
+            val nSig = toNat(signature)
+            return secp256k1_schnorrsig_verify(ctx, nSig, nData, 32, pubkey.ptr) == 1
         }
     }
 
@@ -336,17 +246,15 @@ public object Secp256k1Native : Secp256k1 {
         require(sec.size == 32)
         require(data.size == 32)
         auxrand32?.let { require(it.size == 32) }
-        CallbackHandler(ctx).use { callbackHandler ->
-            memScoped {
-                val nSec = toNat(sec)
-                val nData = toNat(data)
-                val nAuxrand32 = auxrand32?.let { toNat(it) }
-                val nSig = allocArray<UByteVar>(64)
-                val keypair = alloc<secp256k1_keypair>()
-                secp256k1_keypair_create(ctx, keypair.ptr, nSec).requireSuccess(callbackHandler, "secp256k1_keypair_create() failed")
-                secp256k1_schnorrsig_sign32(ctx, nSig, nData, keypair.ptr, nAuxrand32).requireSuccess(callbackHandler, "secp256k1_ecdsa_sign() failed")
-                return nSig.readBytes(64)
-            }
+        memScoped {
+            val nSec = toNat(sec)
+            val nData = toNat(data)
+            val nAuxrand32 = auxrand32?.let { toNat(it) }
+            val nSig = allocArray<UByteVar>(64)
+            val keypair = alloc<secp256k1_keypair>()
+            secp256k1_keypair_create(ctx, keypair.ptr, nSec).requireSuccess("secp256k1_keypair_create() failed")
+            secp256k1_schnorrsig_sign32(ctx, nSig, nData, keypair.ptr, nAuxrand32).requireSuccess("secp256k1_ecdsa_sign() failed")
+            return nSig.readBytes(64)
         }
     }
     

tests/src/commonTest/kotlin/fr/acinq/secp256k1/Secp256k1Test.kt

@@ -275,11 +275,6 @@ class Secp256k1Test {
         val pub0 = Secp256k1.ecdsaRecover(sig, message, 0)
         val pub1 = Secp256k1.ecdsaRecover(sig, message, 1)
         assertTrue(pub.contentEquals(pub0) || pub.contentEquals(pub1))
-
-        // this is a special case, ecdsaRecover explicitly does not check that recid is valid, which triggers our illegal callback handler
-        assertFailsWith(Secp256k1IllegalCallbackException::class) {
-            Secp256k1.ecdsaRecover(sig, message, 4)
-        }
     }
 
     @Test
@@ -357,6 +352,38 @@ class Secp256k1Test {
         }
     }
 
+    @Test
+    fun testInvalidArguments() {
+        assertFails {
+            Secp256k1.pubkeyCreate(ByteArray(32))
+        }
+        assertFails {
+            Secp256k1.pubkeyCreate(Hex.decode("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"))
+        }
+        assertFails {
+            Secp256k1.pubkeyParse(ByteArray(33))
+        }
+        assertFails {
+            Secp256k1.pubkeyParse(Hex.decode("03ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"))
+        }
+        assertFails {
+            Secp256k1.pubKeyCombine(arrayOf())
+        }
+        assertFails {
+            Secp256k1.pubKeyCombine(arrayOf(ByteArray(0)))
+        }
+        assertFails {
+            Secp256k1.signSchnorr(ByteArray(0), Hex.decode("0101010101010101010101010101010101010101010101010101010101010101"), null)
+        }
+        assertFails {
+            Secp256k1.ecdsaRecover(
+                Hex.decode("01010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101"),
+                Hex.decode("0202020202020202020202020202020202020202020202020202020202020202"),
+                -1
+            )
+        }
+    }
+
     @Test
     fun fuzzEcdsaSignVerify() {
         val random = Random.Default