I wants to convert String to binary(0/1 representation) and reverse.
This is my code for converting String to binary.
let String_Data: String = UI_Data.text!
let Binary_Data: Data? = String_Data.data(using: .utf8, allowLossyConversion: false)!
let String_Binary_Data = Binary_Data?.reduce("") { (acc, byte) -> String in
acc + String(byte, radix: 2)
}
But I do not know how to do the opposite. I would be very grateful if you could give me advice for this.
I would start with something like this, although the performance probably isn't spectacular because it involves so many small intermediate strings.
import Foundation
extension UInt8 {
var binaryString: String {
return String(repeating: "0", count: self.leadingZeroBitCount) + String(self, radix: 2)
}
}
extension Data {
var binaryString: String {
return self.map { $0.binaryString }.joined()
}
}
let exampleString = "abcdefghijklmnopqrstuvwxyz"
let exampleData = exampleString.data(using: .utf8)!
print(exampleData.binaryString)
Related
I need to generate the same hash value as the site below.
https://cryptii.com/pipes/hmac
If the key is aaaa and the message is a
The expected hash value is e29f14beeb21a8ee1d1c3b8c2be4cf440584da4d46aff5bacb2ae9aa7deb3271.
But the result is 8c21ecf95763195811ac0513bfa42a29be13b9d895b896af45e115dde9bc7382
Below is my code I don't know what's wrong.
I am wasting 6 hours now... so PLEASE HELP ME... : (
import CommonCrypto
import CryptoKit
enum CryptoAlgorithm {
case MD5, SHA1, SHA224, SHA256, SHA384, SHA512
var HMACAlgorithm: CCHmacAlgorithm {
var result: Int = 0
switch self {
case .MD5: result = kCCHmacAlgMD5
case .SHA1: result = kCCHmacAlgSHA1
case .SHA224: result = kCCHmacAlgSHA224
case .SHA256: result = kCCHmacAlgSHA256
case .SHA384: result = kCCHmacAlgSHA384
case .SHA512: result = kCCHmacAlgSHA512
}
return CCHmacAlgorithm(result)
}
var digestLength: Int {
var result: Int32 = 0
switch self {
case .MD5: result = CC_MD5_DIGEST_LENGTH
case .SHA1: result = CC_SHA1_DIGEST_LENGTH
case .SHA224: result = CC_SHA224_DIGEST_LENGTH
case .SHA256: result = CC_SHA256_DIGEST_LENGTH
case .SHA384: result = CC_SHA384_DIGEST_LENGTH
case .SHA512: result = CC_SHA512_DIGEST_LENGTH
}
return Int(result)
}
}
extension String {
func hmac(algorithm: CryptoAlgorithm, key: String) -> String {
let str = self.cString(using: String.Encoding.utf8)
let strLen = Int(self.lengthOfBytes(using: String.Encoding.utf8))
let digestLen = algorithm.digestLength
let result = UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: digestLen)
let keyStr = key.cString(using: String.Encoding.utf8)
let keyLen = Int(key.lengthOfBytes(using: String.Encoding.utf8))
CCHmac(algorithm.HMACAlgorithm, keyStr!, keyLen, str!, strLen, result)
let digest = stringFromResult(result: result, length: digestLen)
result.deallocate()
result.deinitialize(count: digestLen)
return digest
}
private func stringFromResult(result: UnsafeMutablePointer<CUnsignedChar>, length: Int) -> String {
let hash = NSMutableString()
for i in 0..<length {
hash.appendFormat("%02x", result[i])
}
return String(hash).lowercased()
}
}
public extension Data {
/**
Method creates bytes array from given Data
- Returns: Array of bytes
*/
func bytesArray<T: ExpressibleByIntegerLiteral>() -> [T] {
var bytes = Array<T>(repeating: 0, count: self.count)
(self as NSData).getBytes(&bytes, length:self.count * MemoryLayout<T>.size)
return bytes
}
}
public extension String {
/**
Method creates bytes array from given String
- Returns: Array of bytes
*/
func bytesArray<T: ExpressibleByIntegerLiteral>() -> [T] {
let data = self.data(using: String.Encoding.utf8)!
return data.bytesArray()
}
}
extension Data {
struct HexEncodingOptions: OptionSet {
let rawValue: Int
static let upperCase = HexEncodingOptions(rawValue: 1 << 0)
}
func hexEncodedString(options: HexEncodingOptions = []) -> String {
let format = options.contains(.upperCase) ? "%02hhX" : "%02hhx"
return map { String(format: format, $0) }.joined()
}
var hexDescription: String {
return reduce("") {$0 + String(format: "%02x", $1)}
}
}
print("a".hmac(algorithm: .SHA256, key: Data("aaaa".utf8).hexEncodedString()))
print("a".hmac(algorithm: .SHA256, key: "aaaa").data(using: .utf8)?.base64EncodedString().description)
I am trying to create public base64 key from RSA Private key using Security framework. Here is snippet.
let tag = "com.example.keys.mykey"
public extension SecKey {
static func generateBase64Encoded2048BitRSAKey() throws -> (private: String, public: String) {
let type = kSecAttrKeyTypeRSA
let attributes: [String: Any] =
[kSecAttrKeyType as String: type,
kSecAttrKeySizeInBits as String: 2048
]
var error: Unmanaged<CFError>?
guard let key = SecKeyCreateRandomKey(attributes as CFDictionary, &error),
let data = SecKeyCopyExternalRepresentation(key, &error) as Data?,
let publicKey = SecKeyCopyPublicKey(key),
let publicKeyData = SecKeyCopyExternalRepresentation(publicKey, &error) as Data? else {
throw error!.takeRetainedValue() as Error
}
return (private: data.base64EncodedString(), public: publicKeyData.base64EncodedString())
}
}
do {
let (pvtKey, pubKey) = try SecKey.generateBase64Encoded2048BitRSAKey()
print(pubKey)
} catch let error {
print(error)
}
This is the output
MIIBCgKCAQEA1ZafTYboquQbCTZMEb1IqHKIr8wiDjdn6e0toRajZCQo9W5zuTlEuctrjJJQ08HcOuK3BPFRaFTUP1RBFvnba/T2S1Mc6WVX81b0DmKS8aPJ83TvvQlH3bZjVqFzndXJHJatcXRkZKlbidNQYxV9OYFCRLwgR5PBoJ1P5tp8f8735vIADOBL/93nFywODSjAWLXcyG5tUyRlRGX7eDodL7jqVOFxVMB7K9UOJehPuJQiheykyPSbBSLE6raZbpCHlranTLdihWYFs2tYbxzNrVbXzgKIxDDjrhDLVFvo3beudKQcLQkSO+m2LJIDT91zAnxVQ075AIn80ZHh5kdyQQIDAQAB
But this public key is not getting accepted by our Java server. It is throwing exception for the same.
Here is java snippet
public static void main(String[] args) {
String pubKey = "MIIBCgKCAQEA1ZafTYboquQbCTZMEb1IqHKIr8wiDjdn6e0toRajZCQo9W5zuTlEuctrjJJQ08HcOuK3BPFRaFTUP1RBFvnba/T2S1Mc6WVX81b0DmKS8aPJ83TvvQlH3bZjVqFzndXJHJatcXRkZKlbidNQYxV9OYFCRLwgR5PBoJ1P5tp8f8735vIADOBL/93nFywODSjAWLXcyG5tUyRlRGX7eDodL7jqVOFxVMB7K9UOJehPuJQiheykyPSbBSLE6raZbpCHlranTLdihWYFs2tYbxzNrVbXzgKIxDDjrhDLVFvo3beudKQcLQkSO+m2LJIDT91zAnxVQ075AIn80ZHh5kdyQQIDAQAB";
PublicKey key = getPublic(pubKey);
}
public static PublicKey getPublic(String key) {
PublicKey pbKey = null;
try {
byte[] keyBytes = Base64.getDecoder().decode(key);
System.out.println(keyBytes.length);
X509EncodedKeySpec spec = new X509EncodedKeySpec(keyBytes);
KeyFactory factory = KeyFactory.getInstance("RSA");
pbKey = factory.generatePublic(spec);
} catch (Exception e) {
e.printStackTrace();
}
return pbKey;
}
Here is the exception
java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException: algid parse error, not a sequence
at sun.security.rsa.RSAKeyFactory.engineGeneratePublic(RSAKeyFactory.java:205)
at java.security.KeyFactory.generatePublic(KeyFactory.java:334)
at Main.getPublic(Main.java:40)
at Main.main(Main.java:28)
But the online PEM parser website - https://8gwifi.org/PemParserFunctions.jsp is accepting this public key, which is using bouncycastle library in the background to validate this base64 encoded public key.
The exception is thrown because the ASN.1 DER encoding of an RSA public key generated on iOS is represented with the RSAPublicKey type as defined by PKCS#1, while Java (and many other languages and tools) expect the DER encoding to be represented with the SubjectPublicKeyInfo type as defined by X.509. There are of course two sides where this problem can be solved. And if you choose to convert the DER encoding of the RSA public key at the iOS side, you could use this project I recently published on GitHub. The structure you may be interested in is RSAPublicKeyExporter, which uses the SimpleASN1Writer for converting the DER encoding. The code snippet below shows how to use it:
import RSAPublicKeyExporter
let publicKeyData = ... // Get external representation of RSA public key some how
let x509EncodedKeyData = RSAPublicKeyExporter().toSubjectPublicKeyInfo(publicKeyData)
The answer I posted here contains some information that may be useful in case the exported key is fetched from the keychain.
Thanks guys. Due to some issues with bouncycastle library, we did not used it in backend service. So in iOS, we are including ASN1 header.
struct ASN1 {
let type: UInt8
let length: Int
let data: Data
init?(type: UInt8, arbitraryData data: Data) {
guard data.count > 4 else {
return nil
}
var result = data
let byteArray = [UInt8](result)
for (_, v) in byteArray.enumerated() {
if v == type { // ASN1 SEQUENCE Type
break
}
result = Data(result.dropFirst())
}
guard result.count > 4 else {
return nil
}
guard
let first = result.advanced(by: 0).first, // advanced start from 7.0
let second = result.advanced(by: 1).first,
let third = result.advanced(by: 2).first,
let fourth = result.advanced(by: 3).first
else {
return nil
}
var length = 0
switch second {
case 0x82:
length = ((Int(third) << 8) | Int(fourth)) + 4
break
case 0x81:
length = Int(third) + 3
break
default:
length = Int(second) + 2
break
}
guard result.startIndex + length <= result.endIndex else { // startIndex, endIndex start from 7.0
return nil
}
result = result[result.startIndex..<result.startIndex + length]
self.data = result
self.length = length
self.type = first
}
var last: ASN1? {
get {
var result: Data?
var dataToFetch = self.data
while let fetched = ASN1(type: self.type, arbitraryData: dataToFetch) {
if let range = data.range(of: fetched.data) {
if range.upperBound == data.count {
result = fetched.data
dataToFetch = Data(fetched.data.dropFirst())
} else {
dataToFetch = Data(data.dropFirst(range.upperBound))
}
} else {
break
}
}
return ASN1(type: type, arbitraryData: result!)
}
}
static func wrap(type: UInt8, followingData: Data) -> Data {
var adjustedFollowingData = followingData
if type == 0x03 {
adjustedFollowingData = Data([0]) + followingData // add prefix 0
}
let lengthOfAdjustedFollowingData = adjustedFollowingData.count
let first: UInt8 = type
var bytes = [UInt8]()
if lengthOfAdjustedFollowingData <= 0x80 {
let second: UInt8 = UInt8(lengthOfAdjustedFollowingData)
bytes = [first, second]
} else if lengthOfAdjustedFollowingData > 0x80 && lengthOfAdjustedFollowingData <= 0xFF {
let second: UInt8 = UInt8(0x81)
let third: UInt8 = UInt8(lengthOfAdjustedFollowingData)
bytes = [first, second, third]
} else {
let second: UInt8 = UInt8(0x82)
let third: UInt8 = UInt8(lengthOfAdjustedFollowingData >> 8)
let fourth: UInt8 = UInt8(lengthOfAdjustedFollowingData & 0xFF)
bytes = [first, second, third, fourth]
}
return Data(bytes) + adjustedFollowingData
}
static func rsaOID() -> Data {
var bytes = [UInt8]()
bytes = [0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01, 0x05, 0x00]
return Data(bytes)
}
}
Then called this during generating public key of RSA in swift.
class func RSAPublicKeyBitsFromKey(_ secKey:SecKey) -> Data? {
var queryPublicKey:[String:AnyObject] = [:]
queryPublicKey[kSecClass as String] = kSecClassKey as NSString
queryPublicKey[kSecAttrKeyType as String] = kSecAttrKeyTypeRSA as NSString
if let publicKeyData = SwiftCrypto.publicKeyInData(queryPublicKey, secKey: secKey) {
let bitstringSequence = ASN1.wrap(type: 0x03, followingData: publicKeyData)
let oidData = ASN1.rsaOID()
let oidSequence = ASN1.wrap(type: 0x30, followingData: oidData)
let X509Sequence = ASN1.wrap(type: 0x30, followingData: oidSequence + bitstringSequence)
return X509Sequence
}
return nil
}
So, in this way, I had fixed this issue.
I was trying convert struct to Dictionary in Swift. This was my code:
extension Encodable {
var dictionary: [String: Any]? {
if let data = try? JSONEncoder().encode(self) {
if let dict = try? JSONSerialization.jsonObject(with: data) as? [String: Any] {
return dict
}
return nil
}
return nil
}
}
This works in most situation. But when I try to convert a nested structure which contains unicode characters such as Chinese, this happened:
struct PersonModel: Codable {
var job: String?
var contacts: [ContactSimpleModel]
var manager: ManagerSimpleModel?
}
struct ContactSimpleModel: Codable {
var relation: String
var name: String
}
struct ManagerSimpleModel: Codable {
var name: String
var age: Int
}
let contact1 = ContactSimpleModel(relation: "朋友", name: "宙斯")
let contact2 = ContactSimpleModel(relation: "同学", name: "奥丁")
let manager = ManagerSimpleModel(name: "拉斐尔", age: 31)
let job = "火枪手"
let person = PersonModel(job: job, contacts: [contact1, contact2], manager: manager)
if let dict = person.dictionary {
print(dict)
}
The result of this code is this:
["contacts": <__NSArrayI 0x600002471980>(
{
name = "\U5b99\U65af";
relation = "\U670b\U53cb";
},
{
name = "\U5965\U4e01";
relation = "\U540c\U5b66";
}
)
, "manager": {
age = 31;
name = "\U62c9\U6590\U5c14";
}, "job": 火枪手]
You can see the result. The Chinese characters in those nested structures were become a utf-8 encoding string. The top-level property "job": 火枪手 is right. But the values in those nested structures were not the original string.
Is this a bug of JSONSerialization? Or how to make it right?
More information. I used the result like this:
var sortedQuery = ""
if let dict = person.dictionary {
sortedQuery = dict.sorted(by: {$0.0 < $1.0})
.map({ "\($0)\($1)" })
.joined(separator: "")
}
It was used to check whether the query was legal. The result is not the same as Java or other platform.
The result is perfectly fine. That's the internal string representation – a pre-Unicode legacy – of an array or dictionary when you print it.
Assign the values to a label or text view and you will see the expected characters.
I am working with a variety of structs in Swift that I need to be able to look at the memory of directly.
How can I look at a struct byte for byte?
For example:
struct AwesomeStructure {
var index: Int32
var id: UInt16
var stuff: UInt8
// etc.
}
The compiler will not allow me to do this:
func scopeOfAwesomeStruct() {
withUnsafePointer(to: &self, { (ptr: UnsafePointer<Int8>) in
})
}
Obviously because withUnsafePointer is a templated function that requires the UnsafePointer to be the same type as self.
So, how can I break down self (my structs) into 8 bit pieces? Yes, I want to be able to look at index in 4, 8-bit pieces, and so-on.
(In this case, I'm trying to port a CRC algorithm from C#, but I have been confounded by this problem for other reasons as well.)
edit/update: Xcode 12.5 • Swift 5.4
extension ContiguousBytes {
func object<T>() -> T { withUnsafeBytes { $0.load(as: T.self) } }
}
extension Data {
func subdata<R: RangeExpression>(in range: R) -> Self where R.Bound == Index {
subdata(in: range.relative(to: self) )
}
func object<T>(at offset: Int) -> T { subdata(in: offset...).object() }
}
extension Numeric {
var data: Data {
var source = self
return Data(bytes: &source, count: MemoryLayout<Self>.size)
}
}
struct AwesomeStructure {
let index: Int32
let id: UInt16
let stuff: UInt8
}
extension AwesomeStructure {
init(data: Data) {
index = data.object()
id = data.object(at: 4)
stuff = data.object(at: 6)
}
var data: Data { index.data + id.data + stuff.data }
}
let awesomeStructure = AwesomeStructure(index: 1, id: 2, stuff: 3)
let data = awesomeStructure.data
print(data) // 7 bytes
let structFromData = AwesomeStructure(data: data)
print(structFromData) // "AwesomeStructure(index: 1, id: 2, stuff: 3)\n"
You can use withUnsafeBytes(_:) directly like this:
mutating func scopeOfAwesomeStruct() {
withUnsafeBytes(of: &self) {rbp in
let ptr = rbp.baseAddress!.assumingMemoryBound(to: UInt8.self)
//...
}
}
As already noted, do not export ptr outside of the closure.
And it is not safe even if you have a function that knows the length of the structure. Swift API stability is not declared yet. Any of the layout details of structs are not guaranteed, including the orders of the properties and how they put paddings. Which may be different than the C# structs and may generate the different result than that of C#.
I (and many other developers) believe and expect that the current layout strategy would not change in the near future, so I would write some code like yours. But I do not think it's safe. Remember Swift is not C.
(Though, it's all the same if you copy the contents of a struct into a Data.)
If you want a strictly exact layout with C, you can write a C struct and import it into your Swift project.
Here's a decent first approximation. The trick is to use Swift.withUnsafeBytes(_:) to get a UnsafeRawBufferPointer, which can then be easily converted to Data using Data.init<SourceType>(buffer: UnsafeMutableBufferPointer<SourceType>).
This causes a copy of the memory, so you don't have to worry about any sort of dangling pointer issues.
import Foundation
struct AwesomeStructure {
let index: Int32 = 0x56
let id: UInt16 = 0x34
let stuff: UInt8 = 0x12
}
func toData<T>(_ input: inout T) -> Data {
var data = withUnsafeBytes(of: &input, Data.init)
let alignment = MemoryLayout<T>.alignment
let remainder = data.count % alignment
if remainder == 0 {
return data
}
else {
let paddingByteCount = alignment - remainder
return data + Data(count: paddingByteCount)
}
}
extension Data {
var prettyString: String {
return self.enumerated()
.lazy
.map { byteNumber, byte in String(format:"/* %02i */ 0x%02X", byteNumber, byte) }
.joined(separator: "\n")
}
}
var x = AwesomeStructure()
let d = toData(&x)
print(d.prettyString)
I have a small function that takes a string and returns its MD5 hash value. The problem is, that it expects a UTF8 string, and I need it to calculate a hash value of a byte array encoded with iso-8859-1 (~ansi).
How can I change the following code to accept a byte array of characters, then return its hashed value?
static func md5(_ string: String) -> String {
let context = UnsafeMutablePointer<CC_MD5_CTX>.allocate(capacity: 1)
var digest = Array<UInt8>(repeating:0, count:Int(CC_MD5_DIGEST_LENGTH))
CC_MD5_Init(context)
CC_MD5_Update(context, string, CC_LONG(string.lengthOfBytes(using: String.Encoding.utf8)))
CC_MD5_Final(&digest, context)
context.deallocate(capacity: 1)
var hexString = ""
for byte in digest {
hexString += String(format:"%02x", byte)
}
return hexString
}
The tricky part is the CC_MD5_Update call. Thanks.
You can easily modify your function to take an arbitrary byte
array as argument. CC_MD5_Update is mapped to Swift as
func CC_MD5_Update(_ c: UnsafeMutablePointer<CC_MD5_CTX>!, _ data: UnsafeRawPointer!, _ len: CC_LONG) -> Int32
and you can pass an array as the UnsafeRawPointer parameter:
func md5(bytes: [UInt8]) -> String {
var context = CC_MD5_CTX()
var digest = Array<UInt8>(repeating:0, count:Int(CC_MD5_DIGEST_LENGTH))
CC_MD5_Init(&context)
CC_MD5_Update(&context, bytes, CC_LONG(bytes.count))
CC_MD5_Final(&digest, &context)
return digest.map { String(format: "%02hhx", $0) }.joined()
}
(I have also simplified it a bit.)
Alternatively, pass a Data argument:
func md5(data: Data) -> String {
var context = CC_MD5_CTX()
var digest = Array<UInt8>(repeating:0, count:Int(CC_MD5_DIGEST_LENGTH))
CC_MD5_Init(&context)
data.withUnsafeBytes {
_ = CC_MD5_Update(&context, $0, CC_LONG(data.count))
}
CC_MD5_Final(&digest, &context)
return digest.map { String(format: "%02hhx", $0) }.joined()
}
which can then be used as
let s = "foo"
if let data = s.data(using: .isoLatin1) {
let hash = md5(data: data)
print(hash)
}
Update for Swift 5:
import CommonCrypto
func md5(data: Data) -> String {
var context = CC_MD5_CTX()
var digest = Array<UInt8>(repeating:0, count:Int(CC_MD5_DIGEST_LENGTH))
CC_MD5_Init(&context)
data.withUnsafeBytes {
_ = CC_MD5_Update(&context, $0.baseAddress, CC_LONG(data.count))
}
CC_MD5_Final(&digest, &context)
return digest.map { String(format: "%02hhx", $0) }.joined()
}
If you are sure your 'string' contains only utf8 characters, call CC_MD5_Update with string.utf8 so:
CC_MD5_Update(context, string.utf8, CC_LONG(string.lengthOfBytes(using: String.Encoding.utf8)))
Strings in swift are 'interesting', this is a good read on the topic: https://oleb.net/blog/2016/08/swift-3-strings/
// requires a bridging header with this:
// #import <CommonCrypto/CommonCrypto.h>
func MD5(_ string: String) -> String? {
let length = Int(CC_MD5_DIGEST_LENGTH)
var digest = [UInt8](repeating: 0, count: length)
if let d = string.data(using: String.Encoding.utf8) {
d.withUnsafeBytes { (body: UnsafePointer<UInt8>) in
CC_MD5(body, CC_LONG(d.count), &digest)
}
}
return (0..<length).reduce("") {
$0 + String(format: "%02x", digest[$1])
}
}
Justin Answer : https://gist.github.com/jstn/787da74ab4be9d4cf3cb