private static JweHeader GetHeader()
{
JweHeader jweHeader = new JweHeader();
jweHeader.Alg = "RSA-OAEP";
jweHeader.Enc = "A128GCM";
jweHeader.Kid = "1";
jweHeader.Zip = "gzip";
return(jweHeader);
}
private static string GetEncodeHeader(JweHeader jweHeader)
{
StringBuffer stringBuffer = new StringBuffer();
string headerJson = stringBuffer.Append("alg=")
.Append(jweHeader.Alg)
.Append(", enc=")
.Append(jweHeader.Enc)
.Append(", kid=")
.Append(jweHeader.Kid)
.Append(", zip=")
.Append(jweHeader.Zip)
.ToString();
return(Base64.EncodeToString(Encoding.UTF8.GetBytes(headerJson), Base64Flags.UrlSafe | Base64Flags.NoWrap));
}
public static string GenerateJwe(string issuerId, string dataJson)
{
string jwePrivateKey = Constant.PrivateKey;
string sessionKeyPublicKey = Constant.SessionPublicKey;
string sessionKey = RandomUtils.GenerateSecureRandomFactor(16);
JObject jObject = JObject.Parse(dataJson);
jObject.Add("iss", issuerId);
// The first part: JWE Head
JweHeader jweHeader = GetHeader();
string jweHeaderEncode = GetEncodeHeader(jweHeader);
// The Second part: JWE Encrypted Key
string encryptedKeyEncode = GetEncryptedKey(sessionKey, sessionKeyPublicKey);
// The third part: JWE IV
sbyte[] iv = AESUtils.GetIvByte(12);
string ivHexStr = new string(HwHex.EncodeHexString(iv));
//Java.Lang.String ivHexString = (Java.Lang.String)ivHexStr;
string ivEncode = Base64.EncodeToString(Encoding.UTF8.GetBytes(ivHexStr), Base64Flags.UrlSafe | Base64Flags.NoWrap);
// The fourth part: JWE CipherText empty
string cipherTextEncode = GetCipherText(jObject.ToString(), sessionKey, iv, jweHeader);
// The fifth part: JWE Authentication Tag
string authenticationTagEncode =
GetAuthenticationTag(jwePrivateKey, sessionKey, jObject.ToString(), jweHeaderEncode, ivEncode);
Java.Lang.StringBuilder stringBuilder = new Java.Lang.StringBuilder();
return(stringBuilder.Append(jweHeaderEncode)
.Append(".")
.Append(encryptedKeyEncode)
.Append(".")
.Append(ivEncode)
.Append(".")
.Append(cipherTextEncode)
.Append(".")
.Append(authenticationTagEncode)
.ToString());
}
private static string GetCipherText(string dataJson, string sessionKey, sbyte[] iv, JweHeader jweHeader)
{
if (!"A128GCM".Equals(jweHeader.Enc))
{
System.Console.WriteLine("enc only support A128GCM.");
return("");
}
if (!"gzip".Equals(jweHeader.Zip))
{
System.Console.WriteLine("zip only support gzip.");
return("");
}
string payLoadEncrypt = AESUtils.EncryptByGcm(dataJson, sessionKey, iv);
sbyte[] payLoadEncryptCompressByte = Compress((sbyte[])(Array)Encoding.UTF8.GetBytes(payLoadEncrypt));
string cipherTextEncode = Base64.EncodeToString((byte[])(Array)payLoadEncryptCompressByte, Base64Flags.UrlSafe | Base64Flags.NoWrap);
return(cipherTextEncode);
}