Getting MD5 and SHA256 of NSData and String in Swift

NSData+Hashes.swift

extension NSData {
    private func getHash(
            algorithm: (UnsafePointer<Void>, CC_LONG, UnsafeMutablePointer<UInt8>) -> UnsafeMutablePointer<UInt8>,
            digestLength: Int32
        ) -> String {
        let digestLen = Int(digestLength)
        let fileLen = CUnsignedInt(self.length)
        let buffer = UnsafeMutablePointer<CUnsignedChar>.alloc(digestLen)
        algorithm(self.bytes, fileLen, buffer)

        let hash = NSMutableString()
        for i in 0..<digestLen {
            hash.appendFormat("%02x", buffer[i])
        }

        buffer.destroy()

        return String(format: hash as String)
    }
    func MD5() -> String {
        return getHash(CC_MD5, digestLength: CC_MD5_DIGEST_LENGTH)
    }
    func SHA256() -> String {
        return getHash(CC_SHA256, digestLength: CC_SHA256_DIGEST_LENGTH)
    }
}

String+Hashes.swift

extension String {
    private func getHash(
            algorithm: (UnsafePointer<Void>, CC_LONG, UnsafeMutablePointer<UInt8>) -> UnsafeMutablePointer<UInt8>,
            digestLength: Int32
        ) -> String {
        let str = self.cStringUsingEncoding(NSUTF8StringEncoding)
        let strLen = CUnsignedInt(self.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))
        let digestLen = Int(digestLength)
        let result = UnsafeMutablePointer<CUnsignedChar>.alloc(digestLen)

        algorithm(str!, strLen, result)

        let hash = NSMutableString()
        for i in 0..<digestLen {
            hash.appendFormat("%02x", result[i])
        }

        result.destroy()

        return String(format: hash as String)
        
    }
    func MD5() -> String {
        return getHash(CC_MD5, digestLength: CC_MD5_DIGEST_LENGTH)
    }
    func SHA256() -> String {
        return getHash(CC_SHA256, digestLength: CC_SHA256_DIGEST_LENGTH)
    }
}

Swift-Bridging-Header.h

#import <CommonCrypto/CommonCrypto.h>

This has all been obsoleted by CryptoKit, and Apple has deprecated MD5 since it is insecure.