Digest.swift

import Foundation
import CommonCrypto

public typealias DigestHashFunc = @convention(c)(UnsafePointer<Void>, CC_LONG, UnsafeMutablePointer<UInt8>) -> UnsafeMutablePointer<UInt8>

public extension NSData {
	var md4: NSData { return digetstHash(CC_MD4, CC_MD4_DIGEST_LENGTH) }
	var md5: NSData { return digetstHash(CC_MD5, CC_MD5_DIGEST_LENGTH) }
	var sha1: NSData { return digetstHash(CC_SHA1, CC_SHA1_DIGEST_LENGTH) }
	var sha224: NSData { return digetstHash(CC_SHA224, CC_SHA224_DIGEST_LENGTH) }
	var sha256: NSData { return digetstHash(CC_SHA256, CC_SHA256_DIGEST_LENGTH) }
	var sha384: NSData { return digetstHash(CC_SHA384, CC_SHA384_DIGEST_LENGTH) }
	var sha512: NSData { return digetstHash(CC_SHA512, CC_SHA512_DIGEST_LENGTH) }

	func digetstHash(dfunc: DigestHashFunc, _ dlength: Int32) -> NSData {
		var hash = [UInt8](count: Int(dlength), repeatedValue: 0)
		dfunc(bytes, CC_LONG(length), &hash)
		return NSData(bytes: hash, length: hash.count)
	}
}

public extension String {
	var md4: String { return digetstHash(CC_MD4, CC_MD4_DIGEST_LENGTH) }
	var md5: String { return digetstHash(CC_MD5, CC_MD5_DIGEST_LENGTH) }
	var sha1: String { return digetstHash(CC_SHA1, CC_SHA1_DIGEST_LENGTH) }
	var sha224: String { return digetstHash(CC_SHA224, CC_SHA224_DIGEST_LENGTH) }
	var sha256: String { return digetstHash(CC_SHA256, CC_SHA256_DIGEST_LENGTH) }
	var sha384: String { return digetstHash(CC_SHA384, CC_SHA384_DIGEST_LENGTH) }
	var sha512: String { return digetstHash(CC_SHA512, CC_SHA512_DIGEST_LENGTH) }

	func digetstHash(dfunc: DigestHashFunc, _ dlength: Int32) -> String {
		guard let data = dataUsingEncoding(NSUTF8StringEncoding) else { return "" }
		var hash = [UInt8](count: Int(dlength), repeatedValue: 0)
		dfunc(data.bytes, CC_LONG(data.length), &hash)
		return hash.reduce("") { $0 + String(format: "%02X", $1) }
	}
}