How to hash a string to SHA512 in Swift?

Question

I am building a social media application and I would like some help encoding a password string to SHA512 in Swift. I found the CryptoSwift library on GitHub but I am having a hard time loading it into my Swift project and linking it to my project files. Does anyone know how to accomplish this relatively easily? Thanks in advance, Kyle

Answer 1

Solution for Swift 3:

extension String {

    func sha512() -> String {
        let data = self.data(using: .utf8)!
        var digest = [UInt8](repeating: 0, count: Int(CC_SHA512_DIGEST_LENGTH))
        data.withUnsafeBytes({
            _ = CC_SHA512($0, CC_LONG(data.count), &digest)
        })
        return digest.map({ String(format: "%02hhx", $0) }).joined(separator: "")
    }

}

Answer 2

I find all of the answer ok, but if we should have a true universal solution I think we need to step it up a level.

CC_LONG is just an UInt32 and will not support really large data structures.

This is my solution in Swift 3:

First we create a foundation:

struct Sha512 {
    let context = UnsafeMutablePointer<CC_SHA512_CTX>.allocate(capacity:1)

    init() {
        CC_SHA512_Init(context)
    }

    func update(data: Data) {
        data.withUnsafeBytes { (bytes: UnsafePointer<Int8>) -> Void in
            let end = bytes.advanced(by: data.count)
            for f in sequence(first: bytes, next: { $0.advanced(by: Int(CC_LONG.max)) }).prefix(while: { (current) -> Bool in current < end})  {
                _ = CC_SHA512_Update(context, f, CC_LONG(Swift.min(f.distance(to: end), Int(CC_LONG.max))))
            }
        }
    }

    func final() -> Data {
        var digest = [UInt8](repeating: 0, count:Int(CC_SHA512_DIGEST_LENGTH))
        CC_SHA512_Final(&digest, context)

        return Data(bytes: digest)
    }
}

For convenience we do an extension for Data:

extension Data {
    func sha512() -> Data {
        let s = Sha512()
        s.update(data: self)
        return s.final()
    }
}

And last an extension for String:

extension String {
    func sha512() -> Data {
        return self.data(using: .utf8)!.sha512()
    }
}

This solution can be used for Sha256, MD5 etc. to get a good true universal solutions with Apple's CommonCrypto.

Answer 3

Swift 3

func sha512() -> String {
    let data = self.data(using: .utf8)!
    var digest = [UInt8](repeating: 0, count: Int(CC_SHA512_DIGEST_LENGTH))
    data.withUnsafeBytes({
        _ = CC_SHA512($0, CC_LONG(data.count), &digest)
    })

    return digest.map({ String(format: "%02hhx", $0) }).joined(separator: "")
}

Swift 2.3

func sha512() -> String {
    let data = self.dataUsingEncoding(NSUTF8StringEncoding)!
    var digest = [UInt8](count:Int(CC_SHA512_DIGEST_LENGTH), repeatedValue: 0)
    CC_SHA512(data.bytes, CC_LONG(data.length), &digest)
    let hexBytes = digest.map { String(format: "%02hhx", $0) }

    return hexBytes.joinWithSeparator("")
}

Answer 4

You need to import C library CommonCrypto. You cannot just import CommonCrypto to your swift file since it's not a standalone module.

If you have a bridging header file, you are lucky! Just add this to that file

#import <CommonCrypto/CommonCrypto.h>

There are some articles about different ways to do that.

Then you can use this piece of code to have sha512 available for any string of your choice.

swift 5

extension String {

    public var sha512: String {
        let data = self.data(using: .utf8) ?? Data()
        var digest = [UInt8](repeating: 0, count: Int(CC_SHA512_DIGEST_LENGTH))
        data.withUnsafeBytes {
            _ = CC_SHA512($0.baseAddress, CC_LONG(data.count), &digest)
        }
        return digest.map({ String(format: "%02hhx", $0) }).joined(separator: "")
    }
}