Swift LanguageCryptographic Hashing

MD2, MD4, MD5, SHA1, SHA224, SHA256, SHA384, SHA512 (Swift 3)

These functions will hash either String or Data input with one of eight cryptographic hash algorithms.

The name parameter specifies the hash function name as a String
Supported functions are MD2, MD4, MD5, SHA1, SHA224, SHA256, SHA384 and SHA512

This example requires Common Crypto
It is necessary to have a bridging header to the project:
#import <CommonCrypto/CommonCrypto.h>
Add the Security.framework to the project.


This function takes a hash name and Data to be hashed and returns a Data:

name: A name of a hash function as a String  
data: The Data to be hashed  
returns: the hashed result as Data  
func hash(name:String, data:Data) -> Data? {
    let algos = ["MD2":    (CC_MD2,    CC_MD2_DIGEST_LENGTH),
                 "MD4":    (CC_MD4,    CC_MD4_DIGEST_LENGTH),
                 "MD5":    (CC_MD5,    CC_MD5_DIGEST_LENGTH),
                 "SHA1":   (CC_SHA1,   CC_SHA1_DIGEST_LENGTH),
                 "SHA224": (CC_SHA224, CC_SHA224_DIGEST_LENGTH),
                 "SHA256": (CC_SHA256, CC_SHA256_DIGEST_LENGTH),
                 "SHA384": (CC_SHA384, CC_SHA384_DIGEST_LENGTH),
                 "SHA512": (CC_SHA512, CC_SHA512_DIGEST_LENGTH)]
    guard let (hashAlgorithm, length) = algos[name]  else { return nil }
    var hashData = Data(count: Int(length))

    _ = hashData.withUnsafeMutableBytes {digestBytes in
        data.withUnsafeBytes {messageBytes in
            hashAlgorithm(messageBytes, CC_LONG(data.count), digestBytes)
        }
    }
    return hashData
}

This function takes a hash name and String to be hashed and returns a Data:

name: A name of a hash function as a String  
string: The String to be hashed  
returns: the hashed result as Data  
func hash(name:String, string:String) -> Data? {
    let data = string.data(using:.utf8)!
    return hash(name:name, data:data)
}

Examples:

let clearString = "clearData0123456"
let clearData   = clearString.data(using:.utf8)!
print("clearString: \(clearString)")
print("clearData: \(clearData as NSData)")

let hashSHA256 = hash(name:"SHA256", string:clearString)
print("hashSHA256: \(hashSHA256! as NSData)")

let hashMD5 = hash(name:"MD5", data:clearData)
print("hashMD5: \(hashMD5! as NSData)")

Output:

clearString: clearData0123456
clearData: <636c6561 72446174 61303132 33343536>

hashSHA256: <aabc766b 6b357564 e41f4f91 2d494bcc bfa16924 b574abbd ba9e3e9d a0c8920a>
hashMD5: <4df665f7 b94aea69 695b0e7b baf9e9d6>

HMAC with MD5, SHA1, SHA224, SHA256, SHA384, SHA512 (Swift 3)

These functions will hash either String or Data input with one of eight cryptographic hash algorithms.

The name parameter specifies the hash function name as a String Supported functions are MD5, SHA1, SHA224, SHA256, SHA384 and SHA512

This example requires Common Crypto
It is necessary to have a bridging header to the project:
#import <CommonCrypto/CommonCrypto.h>
Add the Security.framework to the project.

These functions takes a hash name, message to be hashed, a key and return a digest:


hashName: name of a hash function as String  
message:  message as Data  
key:      key as Data  
returns:  digest as Data  
func hmac(hashName:String, message:Data, key:Data) -> Data? {
    let algos = ["SHA1":   (kCCHmacAlgSHA1,   CC_SHA1_DIGEST_LENGTH),
                 "MD5":    (kCCHmacAlgMD5,    CC_MD5_DIGEST_LENGTH),
                 "SHA224": (kCCHmacAlgSHA224, CC_SHA224_DIGEST_LENGTH),
                 "SHA256": (kCCHmacAlgSHA256, CC_SHA256_DIGEST_LENGTH),
                 "SHA384": (kCCHmacAlgSHA384, CC_SHA384_DIGEST_LENGTH),
                 "SHA512": (kCCHmacAlgSHA512, CC_SHA512_DIGEST_LENGTH)]
    guard let (hashAlgorithm, length) = algos[hashName]  else { return nil }
    var macData = Data(count: Int(length))

    macData.withUnsafeMutableBytes {macBytes in
        message.withUnsafeBytes {messageBytes in
            key.withUnsafeBytes {keyBytes in
                CCHmac(CCHmacAlgorithm(hashAlgorithm),
                       keyBytes,     key.count,
                       messageBytes, message.count,
                       macBytes)
            }
        }
    }
    return macData
}

hashName: name of a hash function as String
message:  message as String
key:      key as String
returns:  digest as Data
func hmac(hashName:String, message:String, key:String) -> Data? {
    let messageData = message.data(using:.utf8)!
    let keyData = key.data(using:.utf8)!
    return hmac(hashName:hashName, message:messageData, key:keyData)
}

hashName: name of a hash function as String  
message:  message as String  
key:      key as Data  
returns:  digest as Data  
func hmac(hashName:String, message:String, key:Data) -> Data? {
    let messageData = message.data(using:.utf8)!
    return hmac(hashName:hashName, message:messageData, key:key)
}

// Examples

let clearString = "clearData0123456"
let keyString   = "keyData8901234562"
let clearData   = clearString.data(using:.utf8)!
let keyData     = keyString.data(using:.utf8)!
print("clearString: \(clearString)")
print("keyString:   \(keyString)")
print("clearData: \(clearData as NSData)")
print("keyData:   \(keyData as NSData)")

let hmacData1 = hmac(hashName:"SHA1", message:clearData, key:keyData)
print("hmacData1: \(hmacData1! as NSData)")

let hmacData2 = hmac(hashName:"SHA1", message:clearString, key:keyString)
print("hmacData2: \(hmacData2! as NSData)")

let hmacData3 = hmac(hashName:"SHA1", message:clearString, key:keyData)
print("hmacData3: \(hmacData3! as NSData)")

Output:

clearString: clearData0123456
keyString:   keyData8901234562
clearData: <636c6561 72446174 61303132 33343536>
keyData:   <6b657944 61746138 39303132 33343536 32>

hmacData1: <bb358f41 79b68c08 8e93191a da7dabbc 138f2ae6>
hmacData2: <bb358f41 79b68c08 8e93191a da7dabbc 138f2ae6>
hmacData3: <bb358f41 79b68c08 8e93191a da7dabbc 138f2ae6>