Moving PointOnCurve and Scalar32Bytes to separate files.

BitcoinKit.xcodeproj/project.pbxproj

@@ -216,6 +216,8 @@
 		CFA290702101CDCA001A1BAB /* ScriptTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = CFA2906F2101CDCA001A1BAB /* ScriptTests.swift */; };
 		CFA290722102B635001A1BAB /* ScriptMachine.swift in Sources */ = {isa = PBXBuildFile; fileRef = CFA290712102B635001A1BAB /* ScriptMachine.swift */; };
 		CFA290742102B650001A1BAB /* ScriptMachineTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = CFA290732102B650001A1BAB /* ScriptMachineTests.swift */; };
+		E6A64306224418EB00CD4BFC /* PointOnCurve.swift in Sources */ = {isa = PBXBuildFile; fileRef = E6A64305224418EB00CD4BFC /* PointOnCurve.swift */; };
+		E6A643082244190400CD4BFC /* Scalar32Bytes.swift in Sources */ = {isa = PBXBuildFile; fileRef = E6A643072244190400CD4BFC /* Scalar32Bytes.swift */; };
 		E6C9FB9D2243FF7A000AAE12 /* PointMultiplicationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = E6C9FB9C2243FF7A000AAE12 /* PointMultiplicationTests.swift */; };
 /* End PBXBuildFile section */
 
@@ -444,6 +446,8 @@
 		CFA2906F2101CDCA001A1BAB /* ScriptTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ScriptTests.swift; sourceTree = "<group>"; };
 		CFA290712102B635001A1BAB /* ScriptMachine.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ScriptMachine.swift; sourceTree = "<group>"; };
 		CFA290732102B650001A1BAB /* ScriptMachineTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ScriptMachineTests.swift; sourceTree = "<group>"; };
+		E6A64305224418EB00CD4BFC /* PointOnCurve.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PointOnCurve.swift; sourceTree = "<group>"; };
+		E6A643072244190400CD4BFC /* Scalar32Bytes.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Scalar32Bytes.swift; sourceTree = "<group>"; };
 		E6C9FB9C2243FF7A000AAE12 /* PointMultiplicationTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PointMultiplicationTests.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -621,6 +625,8 @@
 				147494EB201F9E4F006D1CF8 /* Network.swift */,
 				1463E6B52025E99C0033DAAE /* BlockChain.swift */,
 				1463E6B32025E9480033DAAE /* BlockStore.swift */,
+				E6A64305224418EB00CD4BFC /* PointOnCurve.swift */,
+				E6A643072244190400CD4BFC /* Scalar32Bytes.swift */,
 				1482B5E12026B0680098B612 /* Mnemonic.swift */,
 				1482B5E32026F2580098B612 /* WordList.swift */,
 				14839A7B202F79F900A6CB34 /* PaymentURI.swift */,
@@ -1035,6 +1041,7 @@
 				1482B5E42026F2590098B612 /* WordList.swift in Sources */,
 				14839A93202FE6AC00A6CB34 /* FilterLoadMessage.swift in Sources */,
 				14839A9D202FE72600A6CB34 /* TransactionOutPoint.swift in Sources */,
+				E6A643082244190400CD4BFC /* Scalar32Bytes.swift in Sources */,
 				2933014D214FCE150028946B /* TransactionHistoryProvider.swift in Sources */,
 				0C1DE155211D787100FE8E43 /* OP_TOTALSTACK.swift in Sources */,
 				147494E6201F9BF0006D1CF8 /* Encoding.swift in Sources */,
@@ -1097,6 +1104,7 @@
 				0C66CD05212542660049DB89 /* OP_AND.swift in Sources */,
 				0C1DD41021181AF3004BA8A8 /* OP_NUMEQUAL.swift in Sources */,
 				14839AA9202FE7DD00A6CB34 /* VarString.swift in Sources */,
+				E6A64306224418EB00CD4BFC /* PointOnCurve.swift in Sources */,
 				14F37A3E2020A02000D34748 /* SighashType.swift in Sources */,
 				14839A8F202FE68000A6CB34 /* PongMessage.swift in Sources */,
 				294DDE41211B31D600B7F645 /* OP_NOTIF.swift in Sources */,

BitcoinKit/BitcoinKitPrivate.h

@@ -37,12 +37,15 @@ NS_ASSUME_NONNULL_BEGIN
 @end
 
 @interface _Key : NSObject
-+ (NSData *)multiplyECPointX:(NSData *)ecPointX andECPointY:(NSData *)ecPointY withScalar:(NSData *)scalar;
 + (NSData *)computePublicKeyFromPrivateKey:(NSData *)privateKey compression:(BOOL)compression;
 + (NSData *)deriveKey:(NSData *)password salt:(NSData *)salt iterations:(NSInteger)iterations keyLength:(NSInteger)keyLength;
 
 @end
 
+@interface _EllipticCurve : NSObject
++ (NSData *)multiplyECPointX:(NSData *)ecPointX andECPointY:(NSData *)ecPointY withScalar:(NSData *)scalar;
+@end
+
 @interface _HDKey : NSObject
 
 @property (nonatomic, readonly, nullable) NSData *privateKey;

BitcoinKit/BitcoinKitPrivate.m

@@ -68,9 +68,7 @@ + (NSData *)hmacsha512:(NSData *)data key:(NSData *)key {
 
 @end
 
-@implementation _Key
-
-
+@implementation _EllipticCurve
 + (NSData *)multiplyECPointX:(NSData *)ecPointX andECPointY:(NSData *)ecPointY withScalar:(NSData *)scalar {
     BN_CTX *ctx = BN_CTX_new();
     const EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp256k1);
@@ -79,7 +77,6 @@ + (NSData *)multiplyECPointX:(NSData *)ecPointX andECPointY:(NSData *)ecPointY w
     BN_bin2bn(scalar.bytes, (int)scalar.length, multiplication_factor);
 
     BIGNUM *point_x = BN_new();
-
     BN_bin2bn(ecPointX.bytes, (int)ecPointX.length, point_x);
 
     BIGNUM *point_y = BN_new();
@@ -89,26 +86,28 @@ + (NSData *)multiplyECPointX:(NSData *)ecPointX andECPointY:(NSData *)ecPointY w
     EC_POINT_set_affine_coordinates_GFp(group, point, point_x, point_y, ctx);
 
     EC_POINT *point_result_of_ec_multiplication = EC_POINT_new(group);
-
     EC_POINT_mul(group, point_result_of_ec_multiplication, nil, point, multiplication_factor, ctx);
-
+    
     NSMutableData *newPointXAndYPrefixedWithByte = [NSMutableData dataWithLength:65];
     BIGNUM *new_point_x_and_y_as_single_bn = BN_new();
     EC_POINT_point2bn(group, point_result_of_ec_multiplication, POINT_CONVERSION_UNCOMPRESSED, new_point_x_and_y_as_single_bn, ctx);
     BN_bn2bin(new_point_x_and_y_as_single_bn, newPointXAndYPrefixedWithByte.mutableBytes);
-    BN_free(new_point_x_and_y_as_single_bn);
 
+    BN_free(new_point_x_and_y_as_single_bn);
     EC_POINT_free(point_result_of_ec_multiplication);
     EC_POINT_free(point);
     BN_free(multiplication_factor);
     BN_free(point_x);
     BN_free(point_y);
     BN_CTX_free(ctx);
-    NSData* newPointXAndYDataConcatenated = [newPointXAndYPrefixedWithByte subdataWithRange:NSMakeRange(1, 64)];
 
-    return newPointXAndYDataConcatenated;
+    return [newPointXAndYPrefixedWithByte subdataWithRange:NSMakeRange(1, 64)];
 }
 
+@end
+
+@implementation _Key
+
 + (NSData *)computePublicKeyFromPrivateKey:(NSData *)privateKey compression:(BOOL)compression {
     BN_CTX *ctx = BN_CTX_new();
     EC_KEY *key = EC_KEY_new_by_curve_name(NID_secp256k1);

Sources/BitcoinKit/Core/Keys/PrivateKey.swift

@@ -30,66 +30,6 @@ import BitcoinKit.Private
 import BitcoinKitPrivate
 #endif
 
-public struct PointOnCurve {
-
-    public struct Scalar32Bytes {
-        // swiftlint:disable:next nesting
-        public enum Error: Swift.Error {
-            case tooFewBytes(expectedCount: Int, butGot: Int)
-            case tooManyBytes(expectedCount: Int, butGot: Int)
-        }
-        public static let expectedByteCount = 32
-        public let data: Data
-        public init(data: Data) throws {
-            let byteCount = data.count
-            if byteCount < Scalar32Bytes.expectedByteCount {
-                throw Error.tooFewBytes(expectedCount: Scalar32Bytes.expectedByteCount, butGot: byteCount)
-            }
-            if byteCount > Scalar32Bytes.expectedByteCount {
-                throw Error.tooManyBytes(expectedCount: Scalar32Bytes.expectedByteCount, butGot: byteCount)
-            }
-            self.data = data
-        }
-    }
-
-    public enum Error: Swift.Error {
-        case multiplicationResultedInTooFewBytes(expected: Int, butGot: Int)
-    }
-
-    public let x: Scalar32Bytes
-    public let y: Scalar32Bytes
-    public init(x: Scalar32Bytes, y: Scalar32Bytes) {
-        self.x = x
-        self.y = y
-    }
-
-    public init(x xData: Data, y yData: Data) throws {
-        let x = try Scalar32Bytes(data: xData)
-        let y = try Scalar32Bytes(data: yData)
-        self.init(x: x, y: y)
-    }
-
-    public func multiplyBy(scalar: Scalar32Bytes) throws -> PointOnCurve {
-        let xAndY = _Key.multiplyECPointX(x.data, andECPointY: y.data, withScalar: scalar.data)
-        let expectedByteCount = Scalar32Bytes.expectedByteCount * 2
-        guard xAndY.count == expectedByteCount else {
-            throw Error.multiplicationResultedInTooFewBytes(expected: expectedByteCount, butGot: xAndY.count)
-        }
-        let resultX = xAndY.prefix(Scalar32Bytes.expectedByteCount)
-        let resultY = xAndY.suffix(Scalar32Bytes.expectedByteCount)
-        return try PointOnCurve(x: resultX, y: resultY)
-    }
-
-    public func multiplyBy(privateKey: PrivateKey) throws -> PointOnCurve {
-        return try multiplyBy(scalar: privateKey.data)
-    }
-
-    public func multiplyBy(scalar scalarData: Data) throws -> PointOnCurve {
-        let scalar = try Scalar32Bytes(data: scalarData)
-        return try multiplyBy(scalar: scalar)
-    }
-}
-
 public struct PrivateKey {
     @available(*, deprecated, renamed: "data")
     public var raw: Data { return data }
@@ -184,7 +124,7 @@ public struct PrivateKey {
 
     public func publicKeyPoint() throws -> PointOnCurve {
         let xAndY: Data = _Key.computePublicKey(fromPrivateKey: data, compression: false)
-        let expectedLengthOfScalar = PointOnCurve.Scalar32Bytes.expectedByteCount
+        let expectedLengthOfScalar = Scalar32Bytes.expectedByteCount
         let expectedLengthOfKey = expectedLengthOfScalar * 2
         guard xAndY.count == expectedLengthOfKey else {
             fatalError("expected length of key is \(expectedLengthOfKey) bytes, but got: \(xAndY.count)")

Sources/BitcoinKit/Core/PointOnCurve.swift

@@ -0,0 +1,53 @@
+//
+//  PointOnCurve.swift
+//  BitcoinKit
+//
+//  Created by Alexander Cyon on 2019-03-21.
+//  Copyright © 2019 BitcoinKit developers. All rights reserved.
+//
+
+import Foundation
+
+public struct PointOnCurve {
+
+    public let x: Scalar32Bytes
+    public let y: Scalar32Bytes
+
+    public init(x: Scalar32Bytes, y: Scalar32Bytes) {
+        self.x = x
+        self.y = y
+    }
+}
+
+public extension PointOnCurve {
+
+    public enum Error: Swift.Error {
+        case multiplicationResultedInTooFewBytes(expected: Int, butGot: Int)
+    }
+
+    init(x xData: Data, y yData: Data) throws {
+        let x = try Scalar32Bytes(data: xData)
+        let y = try Scalar32Bytes(data: yData)
+        self.init(x: x, y: y)
+    }
+
+    func multiplyBy(scalar: Scalar32Bytes) throws -> PointOnCurve {
+        let xAndY = _EllipticCurve.multiplyECPointX(x.data, andECPointY: y.data, withScalar: scalar.data)
+        let expectedByteCount = Scalar32Bytes.expectedByteCount * 2
+        guard xAndY.count == expectedByteCount else {
+            throw Error.multiplicationResultedInTooFewBytes(expected: expectedByteCount, butGot: xAndY.count)
+        }
+        let resultX = xAndY.prefix(Scalar32Bytes.expectedByteCount)
+        let resultY = xAndY.suffix(Scalar32Bytes.expectedByteCount)
+        return try PointOnCurve(x: resultX, y: resultY)
+    }
+
+    func multiplyBy(privateKey: PrivateKey) throws -> PointOnCurve {
+        return try multiplyBy(scalar: privateKey.data)
+    }
+
+    func multiplyBy(scalar scalarData: Data) throws -> PointOnCurve {
+        let scalar = try Scalar32Bytes(data: scalarData)
+        return try multiplyBy(scalar: scalar)
+    }
+}

Sources/BitcoinKit/Core/Scalar32Bytes.swift

@@ -0,0 +1,28 @@
+//
+//  Scalar32Bytes.swift
+//  BitcoinKit
+//
+//  Created by Alexander Cyon on 2019-03-21.
+//  Copyright © 2019 BitcoinKit developers. All rights reserved.
+//
+
+import Foundation
+
+public struct Scalar32Bytes {
+    public enum Error: Swift.Error {
+        case tooFewBytes(expectedCount: Int, butGot: Int)
+        case tooManyBytes(expectedCount: Int, butGot: Int)
+    }
+    public static let expectedByteCount = 32
+    public let data: Data
+    public init(data: Data) throws {
+        let byteCount = data.count
+        if byteCount < Scalar32Bytes.expectedByteCount {
+            throw Error.tooFewBytes(expectedCount: Scalar32Bytes.expectedByteCount, butGot: byteCount)
+        }
+        if byteCount > Scalar32Bytes.expectedByteCount {
+            throw Error.tooManyBytes(expectedCount: Scalar32Bytes.expectedByteCount, butGot: byteCount)
+        }
+        self.data = data
+    }
+}