I am attempting to export the contents of a PrivateKey (assumed DER) format into a stream of bytes encoded as PEM format.
The link here discusses the use of BouncyCastle and PemWriter to dump a key to PEM format.
Is there a way to create a BouncyCastle object from a PrivateKey object, or some other way to export PrivateKey as PEM byte stream?
The code snippet seems to do the job:
KeyStore keystore = KeyStore.Instance("JKS");
InputStream stream = new FileInputStream("path-to-jks-file");
keystore.load(stream, null);
PrivateKey key = (PrivateKey) keystore.getKey("mykey", "password".toCharArray());
byte[] prvkey = key.getEncoded();
String encoded = Base64.getEncoder().encodeToString(prvkey);
String key_pem = "-----BEGIN PRIVATE KEY-----" + encoded + "-----END PRIVATE KEY-----";
Related
i am trying to use AES GCM for decrypting files (small and large files) on Android.
I have tried to do it like this tutorial
https://proandroiddev.com/security-best-practices-symmetric-encryption-with-aes-in-java-7616beaaade9
But there is only written i should use CiperInputstream if i want to encrypt big files.
So this is the code now
SecureRandom secureRandom = new SecureRandom();
byte[] key = new byte[16];
secureRandom.nextBytes(key);
SecretKey secretKey = SecretKeySpec(key, "AES");
byte[] iv = new byte[12]; //NEVER REUSE THIS IV WITH SAME KEY
secureRandom.nextBytes(iv);
final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec parameterSpec = new GCMParameterSpec(128, iv); //128 bit auth tag length
cipher.init(Cipher.ENCRYPT_MODE, secretKey, parameterSpec);
byte[] cipherText = cipher.doFinal(plainText);
ByteBuffer byteBuffer = ByteBuffer.allocate(4 + iv.length + cipherText.length);
byteBuffer.putInt(iv.length);
byteBuffer.put(iv);
byteBuffer.put(cipherText);
byte[] cipherMessage = byteBuffer.array();
So now i have created the CiperInputStream, how to encrypt, add the IV and at least save the file?
FileInputStream inputStream = new FileInputStream(plainText);
CipherInputStream cis = new CipherInputStream(inputStream, cipherEnc);
Furthermore i want to upload the file, if it is possible without saving the ecnrypted file first.
Currently i upload unencrypted files to a webserver with a given link (seafile).
I just pass the path of the file to a function and then upload it with OkHttpClient
I have X509 Signing Certificate inside of a string like:
var signingCertificate = -----BEGIN CERTIFICATE-----\r\nMIICTjCCAbegAw.........-----END CERTIFICATE-----
Now I want to read the content of this certificate. i know we can do it using X509Certificate2 object but that reads from file directly. Is there anyway to read the content from string?
You can convert your string to byte array, and create a X509Certificate2 object from it.
byte[] bytes = Encoding.ASCII.GetBytes(signingCertificate);
var x509Certificate2 = new X509Certificate2(bytes);
I would like to use encryption to send traffic to my F5 BIG IP load balancer and have it use its own native CRYPTO:: methods to decrypt a base64 encoded string.
I am able to encrypt and decrypt a string within the appliance and within a Visual Studio 2012 console application but I cannot decrypt an encrypted string in the opposing environment.
Any suggestion here as to how to get the following keys in a compatible format that CRYPTO or C# understands would go a long way!
// C# key and vector declaration:
private const string AesIV = #"!QAZ2WSX#EDC4RFV";
private const string AesKey = #"5TGB&YHN7UJM(IK<";
It appears that in CRYPTO:: it needs it in hex format, I tried to convert it as seen below but that didnt help me.
C# console app code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Security.Cryptography;
using System.Threading;
namespace ssoconsole_encrypt
{
class Program
{
private const string AesIV = #"!QAZ2WSX#EDC4RFV";
private const string AesKey = #"5TGB&YHN7UJM(IK<";
// set key "abed1ddc04fbb05856bca4a0ca60f21e"
//set iv "d78d86d9084eb9239694c9a733904037"
// set key "56bca4a0ca60f21e"
// set iv "39694c9a73390403"
/// <summary>
/// AES Encryption
/// </summary>
///
static public string Encrypt(string text)
{
// AesCryptoServiceProvider
AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
aes.BlockSize = 128;
aes.KeySize = 256;
aes.IV = Encoding.UTF8.GetBytes(AesIV);
aes.Key = Encoding.UTF8.GetBytes(AesKey);
string keyme = BitConverter.ToString(aes.Key);
string ivme = BitConverter.ToString(aes.IV);
Console.WriteLine(string.Format("The converted key is: {0}",keyme));
Console.WriteLine(string.Format("The converted iv is: {0}", ivme));
Console.WriteLine(System.Text.Encoding.UTF8.GetString(aes.Key));
// Thread.Sleep(10000);
//Console.WriteLine(aes.Key.ToString());
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
// aes.Padding = PaddingMode.Zeros;
// Convert string to byte array
//byte[] src = Encoding.Unicode.GetBytes(text);
byte[] src = Encoding.UTF8.GetBytes(text);
// encryption
using (ICryptoTransform encrypt = aes.CreateEncryptor())
{
byte[] dest = encrypt.TransformFinalBlock(src, 0, src.Length);
// Convert byte array to Base64 strings
return Convert.ToBase64String(dest);
}
}
/// <summary>
/// AES decryption
/// </summary>
static public string Decrypt(string text)
{
// AesCryptoServiceProvider
AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
aes.BlockSize = 128;
aes.KeySize = 256;
aes.IV = Encoding.UTF8.GetBytes(AesIV);
aes.Key = Encoding.UTF8.GetBytes(AesKey);
//aes.IV = Encoding.UTF8.GetBytes(#"01020304050607080900010203040506");
//aes.Key = Encoding.UTF8.GetBytes(#"01020304050607080900010203040506");
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.PKCS7;
// Convert Base64 strings to byte array
byte[] src = System.Convert.FromBase64String(text);
try
{
// decryption
using (ICryptoTransform decrypt = aes.CreateDecryptor())
{
byte[] dest = decrypt.TransformFinalBlock(src, 0, src.Length);
// return Encoding.Unicode.GetString(dest);
return Encoding.UTF8.GetString(dest);
}
}
catch (CryptographicException e)
{
return e.ToString();
}
}
static void Main()
{
string username = "jschoombee";
string encrypted = Encrypt(username);
string decrypted = Decrypt(encrypted);
// string decrypted = Decrypt("epvhTN55JnnVV9DBn1Cbsg==");
// string decrypted = Decrypt(encrypted);
Console.WriteLine(string.Format("jschoombee encrypted is : {0}",encrypted));
Console.WriteLine(string.Format("the Decrypted username for jp is : {0}", decrypted));
Thread.Sleep(1000000);
}
}
}
This is the Console Output:
The converted key is: 35-54-47-42-26-59-48-4E-37-55-4A-4D-28-49-4B-3C
The converted iv is: 21-51-41-5A-32-57-53-58-23-45-44-43-34-52-46-56
5TGB&YHN7UJM(IK<
jschoombee encrypted is : tGG9Un6VqcAOTQawlxwRXg==
the Decrypted username for jp is : jschoombee
This it the F5 / TCL code:
when RULE_INIT {
set static::hexkey "355447422659484E37554A4D28494B3C"
log local0.info"====Rule_Init===="
log local0.info "Key is $static::hexkey"
log local0.info"================="
}
when HTTP_REQUEST_DATA {
set iv "2151415A325753582345444334524656"
set text_to_encrypt "jschoombee"
set enc_out_no_binary [CRYPTO::encrypt -alg aes-256-cbc -keyhex $static::hexkey -ivhex $iv $text_to_encrypt]
set dec_in [CRYPTO::decrypt -alg aes-256-cbc -keyhex $static::hexkey -ivhex $iv $enc_out_no_binary]
log local0.info "The decrypted NO binary $dec_in"
log local0.info "The Encrypted NO binary Base64 is: [b64encode "$enc_out_no_binary"]"
binary scan $enc_out_no_binary H* enc_hex
log local0.info "The Encrypted NO binary Hex is: $enc_hex"
log local0.info "This is the IV $iv"
HTTP::release
}
The F5/TCL Output Log File:
Feb 11 13:05:45 AMS4-LB-01 info tmm1[9650]: <HTTP_REQUEST_DATA>: The decrypted NO binary jschoombee
Feb 11 13:05:45 AMS4-LB-01 info tmm1[9650]: <HTTP_REQUEST_DATA>: The Encrypted NO binary Base64 is: Rlz4cC9SlpRyON4cZI+dtQ==
Feb 11 13:05:45 AMS4-LB-01 info tmm1[9650]: <HTTP_REQUEST_DATA>: The Encrypted NO binary Hex is: 465cf8702f5296947238de1c648f9db5
Feb 11 13:05:45 AMS4-LB-01 info tmm1[9650]: <HTTP_REQUEST_DATA>: This is the IV 2151415A325753582345444334524656
There are some very strange things happening in your code regarding the key and IV.
First of all the key you've specified is 16 characters. In UTF-8 those result in 16 bytes. You are however specifying a key of 32 bytes (256 bits) in your C# code. Also be warned that many libraries (incorrectly) use AES-256 to mean Rijndael with a 256 bit block size. It's probably better to just use AES-128 and focus on making your protocol and code secure.
Second, a key can never be a character string. A character string normally is restricted with regards to which values can be used. E.g. control codes cannot be entered. This means that your key will never reach its intended strength. If you want to use a static key, you should specify it in hexadecimals as you do in your F5 code.
A static IV does not make much sense. The whole idea of the IV is to make sure that you will generate a different ciphertext if you encrypt a block with a value already processed. So please use a random IV, and place it in front of your ciphertext.
You seem to have the hang on using encoding/decoding on your plaintext (UTF-8) and ciphertext (Base 64). So please try and follow the advice given above and try again.
I have to write a standalone java program to decrypt password from file,using Symmetric key for password decryption. I didn't work with encryption and decryption before. can anybody give any suggestion how can i do this.I need your guidance.
maybe you need something like this
private static final String ALGORITHM = "AES";
....
....
Key key = new SecretKeySpec(new String("here is your symmetric key").getBytes(), ALGORITHM);
Cipher c = Cipher.getInstance(ALGORITHM);
//dencript mode (passes the key)
c.init(Cipher.DECRYPT_MODE, key);
//Decode base64 to get bytes
byte[] encBytes = new BASE64Decoder().decodeBuffer(encryptedValue);
// Decrypt
byte[] plainTxtBytes = c.doFinal(encBytes);
// Decode
String decryptedValue = new String(plainTxtBytes , "UTF-8");
Here are some resources:
http://www.javamex.com/tutorials/cryptography/symmetric.shtml
http://www.java2s.com/Code/Java/Security/EncryptionandDecryptionusingSymmetricKeys.htm
http://www.flexiprovider.de/examples/ExampleCrypt.html (This uses files as well)
Following is my Java applet code
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
byte[] privKeyBytes = loadPriavteKeyFromFile(fileName, new String(txtPassword.getPassword()));
PKCS8EncodedKeySpec privSpec = new PKCS8EncodedKeySpec(privKeyBytes);
RSAPrivateKey privKey = (RSAPrivateKey) keyFactory.generatePrivate(privSpec);
Cipher rsaCipher = Cipher.getInstance("RSA");
rsaCipher.init(Cipher.ENCRYPT_MODE, privKey);
byte[] ciphertext = null;
ciphertext = rsaCipher.doFinal(xmlToSign.getBytes());
String urlString = "http://localhost:3290/SignApplet.aspx";
String senddata = Base64.encodeBase64String(ciphertext);
doHttpUrlConnectionAction(urlString,senddata.getBytes());
JOptionPane.showMessageDialog(this, "XML successfully signed and sent to server.");
on the server side i am trying too decrypt the byte using the public key
byte[] b;
b = Request.BinaryRead(178);
string encodedbytes = new System.Text.UTF8Encoding().GetString(b);
b = Convert.FromBase64String(encodedbytes);
Debug.WriteLine("decrypted bytes:" + new System.Text.UTF8Encoding().GetString(b));
// The path to the certificate.
string Certificate = #"c:\certs\lafa801114sd3.cer";
//// Load the certificate into an X509Certificate object.
X509Certificate cert = new X509Certificate(Certificate);
RSACryptoServiceProvider publicprovider = (RSACryptoServiceProvider)CertUtil.GetCertPublicKey(cert);
byte[] decbytes = publicprovider.Decrypt(b, false);
Debug.WriteLine("decrypted bytes" + new System.Text.UTF8Encoding().GetString(decbytes));
can any one help in following exception which i am getting at byte[] decbytes = publicprovider.Decrypt(b, false); line
A first chance exception of type 'System.Security.Cryptography.CryptographicException' occurred in mscorlib.dll
Key does not exist.
and the certificate is not installed in nay key store.Also i can successfully decrypt the data using Java servlet .
i am using asp.net vs2010 on windows 7
the public and private keys are stored in separate files
Here are a few articles that might help you: Java RSA Encrypt - Decrypt .NET (which seems like what you are looking for)
and http://www.jensign.com/JavaScience/dotnet/RSAEncrypt/