generate hmac swift
enum HMACAlgorithm {
case MD5, SHA1, SHA224, SHA256, SHA384, SHA512
func toCCHmacAlgorithm() -> CCHmacAlgorithm {
var result: Int = 0
switch self {
case .MD5:
result = kCCHmacAlgMD5
case .SHA1:
result = kCCHmacAlgSHA1
case .SHA224:
result = kCCHmacAlgSHA224
case .SHA256:
result = kCCHmacAlgSHA256
case .SHA384:
result = kCCHmacAlgSHA384
case .SHA512:
result = kCCHmacAlgSHA512
}
return CCHmacAlgorithm(result)
}
func digestLength() -> Int {
var result: CInt = 0
switch self {
case .MD5:
result = CC_MD5_DIGEST_LENGTH
case .SHA1:
result = CC_SHA1_DIGEST_LENGTH
case .SHA224:
result = CC_SHA224_DIGEST_LENGTH
case .SHA256:
result = CC_SHA256_DIGEST_LENGTH
case .SHA384:
result = CC_SHA384_DIGEST_LENGTH
case .SHA512:
result = CC_SHA512_DIGEST_LENGTH
}
return Int(result)
}
}
extension String {
func hmac(algorithm: HMACAlgorithm, key: String) -> String {
let cKey = key.cString(using: String.Encoding.utf8)
let cData = self.cString(using: String.Encoding.utf8)
let result = UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: algorithm.digestLength())
CCHmac(algorithm.toCCHmacAlgorithm(), cKey!, strlen(cKey!), cData!, strlen(cData!), result)
let hmacData:NSData = NSData(bytes: result, length: (Int(algorithm.digestLength())))
let hmacBase64 = hmacData.base64EncodedString()
return String(hmacBase64)
}
}