Después de leer las otras respuestas aquí (y necesitar también admitir otros tipos de hash), escribí una extensión de cadena que maneja múltiples tipos de hash y tipos de salida.
NOTA: CommonCrypto está incluido en Xcode 10, por lo que puede simplemente import CommonCrypto
sin tener que meterse con un encabezado puente si tiene instalada la última versión de Xcode ... De lo contrario, es necesario un encabezado puente.
ACTUALIZACIÓN: Ambos Swift 4 y 5 usan el mismo archivo String + Crypto.swift a continuación.
Hay un archivo Data + Crypto.swift separado para Swift 5 (ver más abajo) como la API para 'withUnsafeMutableBytes' y 'withUnsafeBytes' cambiada entre Swift 4 y 5.
String + Crypto.swift - (para Swift 4 y 5)
import Foundation
import CommonCrypto
// Defines types of hash string outputs available
public enum HashOutputType {
// standard hex string output
case hex
// base 64 encoded string output
case base64
}
// Defines types of hash algorithms available
public enum HashType {
case md5
case sha1
case sha224
case sha256
case sha384
case sha512
var length: Int32 {
switch self {
case .md5: return CC_MD5_DIGEST_LENGTH
case .sha1: return CC_SHA1_DIGEST_LENGTH
case .sha224: return CC_SHA224_DIGEST_LENGTH
case .sha256: return CC_SHA256_DIGEST_LENGTH
case .sha384: return CC_SHA384_DIGEST_LENGTH
case .sha512: return CC_SHA512_DIGEST_LENGTH
}
}
}
public extension String {
/// Hashing algorithm for hashing a string instance.
///
/// - Parameters:
/// - type: The type of hash to use.
/// - output: The type of output desired, defaults to .hex.
/// - Returns: The requested hash output or nil if failure.
public func hashed(_ type: HashType, output: HashOutputType = .hex) -> String? {
// convert string to utf8 encoded data
guard let message = data(using: .utf8) else { return nil }
return message.hashed(type, output: output)
}
}
SWIFT 5 - Datos + Crypto.swift
import Foundation
import CommonCrypto
extension Data {
/// Hashing algorithm that prepends an RSA2048ASN1Header to the beginning of the data being hashed.
///
/// - Parameters:
/// - type: The type of hash algorithm to use for the hashing operation.
/// - output: The type of output string desired.
/// - Returns: A hash string using the specified hashing algorithm, or nil.
public func hashWithRSA2048Asn1Header(_ type: HashType, output: HashOutputType = .hex) -> String? {
let rsa2048Asn1Header:[UInt8] = [
0x30, 0x82, 0x01, 0x22, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x82, 0x01, 0x0f, 0x00
]
var headerData = Data(rsa2048Asn1Header)
headerData.append(self)
return hashed(type, output: output)
}
/// Hashing algorithm for hashing a Data instance.
///
/// - Parameters:
/// - type: The type of hash to use.
/// - output: The type of hash output desired, defaults to .hex.
/// - Returns: The requested hash output or nil if failure.
public func hashed(_ type: HashType, output: HashOutputType = .hex) -> String? {
// setup data variable to hold hashed value
var digest = Data(count: Int(type.length))
_ = digest.withUnsafeMutableBytes{ digestBytes -> UInt8 in
self.withUnsafeBytes { messageBytes -> UInt8 in
if let mb = messageBytes.baseAddress, let db = digestBytes.bindMemory(to: UInt8.self).baseAddress {
let length = CC_LONG(self.count)
switch type {
case .md5: CC_MD5(mb, length, db)
case .sha1: CC_SHA1(mb, length, db)
case .sha224: CC_SHA224(mb, length, db)
case .sha256: CC_SHA256(mb, length, db)
case .sha384: CC_SHA384(mb, length, db)
case .sha512: CC_SHA512(mb, length, db)
}
}
return 0
}
}
// return the value based on the specified output type.
switch output {
case .hex: return digest.map { String(format: "%02hhx", $0) }.joined()
case .base64: return digest.base64EncodedString()
}
}
}
SWIFT 4 - Datos + Crypto.swift
import Foundation
import CommonCrypto
extension Data {
/// Hashing algorithm that prepends an RSA2048ASN1Header to the beginning of the data being hashed.
///
/// - Parameters:
/// - type: The type of hash algorithm to use for the hashing operation.
/// - output: The type of output string desired.
/// - Returns: A hash string using the specified hashing algorithm, or nil.
public func hashWithRSA2048Asn1Header(_ type: HashType, output: HashOutputType = .hex) -> String? {
let rsa2048Asn1Header:[UInt8] = [
0x30, 0x82, 0x01, 0x22, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x82, 0x01, 0x0f, 0x00
]
var headerData = Data(bytes: rsa2048Asn1Header)
headerData.append(self)
return hashed(type, output: output)
}
/// Hashing algorithm for hashing a Data instance.
///
/// - Parameters:
/// - type: The type of hash to use.
/// - output: The type of hash output desired, defaults to .hex.
/// - Returns: The requested hash output or nil if failure.
public func hashed(_ type: HashType, output: HashOutputType = .hex) -> String? {
// setup data variable to hold hashed value
var digest = Data(count: Int(type.length))
// generate hash using specified hash type
_ = digest.withUnsafeMutableBytes { (digestBytes: UnsafeMutablePointer<UInt8>) in
self.withUnsafeBytes { (messageBytes: UnsafePointer<UInt8>) in
let length = CC_LONG(self.count)
switch type {
case .md5: CC_MD5(messageBytes, length, digestBytes)
case .sha1: CC_SHA1(messageBytes, length, digestBytes)
case .sha224: CC_SHA224(messageBytes, length, digestBytes)
case .sha256: CC_SHA256(messageBytes, length, digestBytes)
case .sha384: CC_SHA384(messageBytes, length, digestBytes)
case .sha512: CC_SHA512(messageBytes, length, digestBytes)
}
}
}
// return the value based on the specified output type.
switch output {
case .hex: return digest.map { String(format: "%02hhx", $0) }.joined()
case .base64: return digest.base64EncodedString()
}
}
}
Editar: dado que el hash realmente ocurre en los datos, divido el algoritmo de hash en una extensión de datos. Esto permite que el mismo algoritmo se utilice también para operaciones hash de fijación de certificados SSL.
Aquí hay un breve ejemplo de cómo puede usarlo para una operación de fijación de SSL:
// Certificate pinning - get certificate as data
let data: Data = SecCertificateCopyData(serverCertificate) as Data
// compare hash of server certificate with local (expected) hash value
guard let serverHash = data.hashWithRSA2048Asn1Header(.sha256, output: .base64), serverHash == storedHash else {
print("SSL PINNING: Server certificate hash does not match specified hash value.")
return false
}
de vuelta a la respuesta original
Probé los algoritmos hash usando esto:
let value = "This is my string"
if let md5 = value.hashed(.md5) {
print("md5: \(md5)")
}
if let sha1 = value.hashed(.sha1) {
print("sha1: \(sha1)")
}
if let sha224 = value.hashed(.sha224) {
print("sha224: \(sha224)")
}
if let sha256 = value.hashed(.sha256) {
print("sha256: \(sha256)")
}
if let sha384 = value.hashed(.sha384) {
print("sha384: \(sha384)")
}
if let sha512 = value.hashed(.sha512) {
print("sha512: \(sha512)")
}
y estos son los resultados impresos:
md5: c2a9ce57e8df081b4baad80d81868bbb
sha1: 37fb219bf98bee51d2fdc3ba6d866c97f06c8223
sha224: f88e2f20aa89fb4dffb6bdc62d7bd75e1ba02574fae4a437c3bf49c7
sha256: 9da6c02379110815278b615f015f0b254fd3d5a691c9d8abf8141655982c046b
sha384: d9d7fc8aefe7f8f0a969b132a59070836397147338e454acc6e65ca616099d03a61fcf9cc8c4d45a2623145ebd398450
sha512: 349cc35836ba85915ace9d7f895b712fe018452bb4b20ff257257e12adeb1e83ad780c6568a12d03f5b2cb1e3da23b8b7ced9012a188ef3855e0a8f3db211883