Validate lower and upper case eth address

Sources/Ethereum/EthereumAddress.swift

@@ -18,9 +18,15 @@ public struct EthereumAddress: Address, Hashable {
 
     /// Validates that the string is a valid address.
     static public func isValid(string: String) -> Bool {
+
+        guard !isAdressWithoutChecksum(string: string) else {
+            return true
+        }
+
         guard let data = Data(hexString: string) else {
             return false
         }
+
         let eip55String = EthereumAddress.computeEIP55String(for: data)
         return string == eip55String
     }
@@ -44,7 +50,7 @@ public struct EthereumAddress: Address, Hashable {
 
     /// Creates an address with an hexadecimal string representation.
     public init?(string: String) {
-        guard let data = Data(hexString: string), data.count == EthereumAddress.size else {
+        guard let data = Data(hexString: string), EthereumAddress.isValid(data: data) else {
             return nil
         }
         self.data = data
@@ -85,4 +91,29 @@ extension EthereumAddress {
 
         return string
     }
+
+    fileprivate static func isAdressWithoutChecksum(string: String) -> Bool {
+        guard string.hasPrefix("0x"), let data = Data(hexString: string), isValid(data: data) else {
+            return false
+        }
+
+        var hasUppers: Bool = false
+        var hasLowers: Bool = false
+
+        for character in string {
+            switch character {
+            case "A", "B", "C", "D", "E", "F": hasUppers = true
+            case "a", "b", "c", "d", "e", "f": hasLowers = true
+            default: break
+            }
+        }
+
+        // If all characters are uppercase or lowercase, return true
+        if (hasUppers && !hasLowers) || (!hasUppers && hasLowers) {
+            return true
+        }
+
+        return false
+    }
+
 }

Tests/Ethereum/EthereumAddressTests.swift

@@ -8,6 +8,15 @@ import TrustCore
 import XCTest
 
 class EthereumAddressTests: XCTestCase {
+
+    func testValidUpperCaseEthAddress() {
+        XCTAssertTrue(EthereumAddress.isValid(string: "0xFA52274DD61E1643D2205169732F29114BC240B3"))
+    }
+
+    func testValidLoverCaseEthAddress() {
+        XCTAssertTrue(EthereumAddress.isValid(string: "0xfa52274dd61e1643d2205169732f29114bc240b3"))
+    }
+
     func testInvalid() {
         XCTAssertNil(EthereumAddress(string: "abc"))
         XCTAssertNil(EthereumAddress(string: "aaeb60f3e94c9b9a09f33669435e7ef1beaed"))