We have an C++ application where it encrypts password using AES algorithm through openssl API's (EVP_EncryptInit_ex, EVP_EncryptUpdate, EVP_EncryptFinal_ex).
Now I try to develop UWP application through which I want to do same authentication as the above legacy app does.
But when I'm using API's from "Windows.Security.Cryptography" my authentication fails as the encrypted data output is different from the legacy app, so decryption fails and there by authentication.
Legacy app uses one Key and initialization vector and same are used in my UWP app also. Legacy app uses cipher mode CBC, I had used "AesCbcPKCS7" in my UWP but the encrypted output is different.
I also tried just "AesCbc" and padded data as per PKCS7 padding manually still the encrypted output is different and my authentication is failing.
Kindly help with the above issue.
Some of Legacy App Code API Flow Sample:
EVP_CIPHER_CTX_init(&ctx);
EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, key, iv);
EVP_EncryptUpdate(&ctx, output, &nOutputSize, input, strlen((const char *)input)+1);
EVP_EncryptFinal_ex(&ctx, output + nOutputSize, &nTmplen);
EVP_CIPHER_CTX_cleanup(&ctx);
UWP Code sample below:
IBuffer iBuf = CryptographicBuffer.ConvertStringToBinary(strPwd, BinaryStringEncoding.Utf8);
IBuffer iPubKey = CryptographicBuffer.CreateFromByteArray(PUB_KEY);
SymmetricKeyAlgorithmProvider objAlg = SymmetricKeyAlgorithmProvider.OpenAlgorithm(SymmetricAlgorithmNames.AesCbcPkcs7);
CryptographicKey cryptKey = objAlg.CreateSymmetricKey(iPubKey);
IBuffer iv = CryptographicBuffer.CreateFromByteArray(INIT_VECTOR);
IBuffer encryptPwd = CryptographicEngine.Encrypt(cryptKey, iBuf, iv);
string strEncPwd = CryptographicBuffer.EncodeToBase64String(encryptPwd);
Related
I have the next code that perfectly works encrypting and decrypting in net framework even with a invalid key for RijndaelManaged, but now in the netCore it doesn’t work because its needs a 16 bytes key, I want to recreate the key that the library in net frameworks makes with a key expansion to decrypt in a net core app, but I don’t now how
I found a similar problem but in PHP here RijndaelManaged.CreateEncryptor key expansion, but it says “just chop off the last 2 bytes” but of what? and how I complete the rest of bytes?
//Code tha works in the framework app
///8 bytes
_key = System.Text.ASCIIEncoding.UTF8.GetBytes("abcdefgh");
//16 bytes
_iv = System.Text.ASCIIEncoding.UTF8.GetBytes("abcdefghijklmnop");
_provider = new RijndaelManaged();
_provider.Mode = CipherMode.CBC;
_provider.KeySize = 128;
_provider.CreateEncryptor(_key, _iv)
I want to verify a private key signed SHA256 hash using the CryptographicEngine in a UWP application. The hash is created externally and is signed with a private RSA key with passphrase. For this example however, I also generate the unsigned hash. Both hashes are then compared at the end to verify that they are the same.
I have created my private and public keys using OSX command line, specified in this blog.
This gave me two .pem files. My public key has the following structure:
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA3fasaNKpXDf4B4ObQ76X
qOaSRaedFCAHvsW4G0PzxL/...ETC ETC
-----END PUBLIC KEY-----
Here is my C# code to decrypt the hash:
//HASH THE INPUT STRING
var inputText = "stringtohash";
// put the string in a buffer, UTF-8 encoded...
IBuffer input = CryptographicBuffer.ConvertStringToBinary(inputText,
BinaryStringEncoding.Utf8);
// hash it...
var hasher = HashAlgorithmProvider.OpenAlgorithm("SHA256");
IBuffer hashed = hasher.HashData(input);
// format it...
string ourhash = CryptographicBuffer.EncodeToBase64String(hashed);
Debug.WriteLine(ourhash);
//CONVERT EXTERNAL HASH TO BUFFER
IBuffer data = CryptographicBuffer.DecodeFromBase64String("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");
//CONVERT PUBLIC KEY TO BUFFER
IBuffer publickey = CryptographicBuffer.DecodeFromBase64String("MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA3fasaNKpXDf4B4ObQ76XqOaSRaedFCAHvsW4G0PzxL / RuAQFz80esZPyyDCps1PAbTKzQ + QblChPo7PJkbsU4HzNN4PIRGh5xum6SRmdvOowrlTUtyxdOkRJoFxmiR / VCea + PUspt26F7PLcK9ao5 + hVzMvPuqdYenqzd01f1t5hQEhFQ9qjB6Es8fpizHd / RSRfZ7n6rVKm9wYfCRLB7GJ7IHhWGuZrx9fjzsbW8eagu06qRhnUuR5oDVjXC8ZeazsRiw50xMuOzkhX9Oo081IYikwCgseJmQhT7vF4lZoyeB4qJpwTCA + glSy1w9N8ZfxyXK8QaT2RsrBrzl0ZCwIDAQAB");
// Open an asymmetric algorithm provider for the specified algorithm.
AsymmetricKeyAlgorithmProvider rsa = AsymmetricKeyAlgorithmProvider.OpenAlgorithm(AsymmetricAlgorithmNames.RsaPkcs1);
// Import Key
CryptographicKey key = rsa.ImportPublicKey(publickey, CryptographicPublicKeyBlobType.X509SubjectPublicKeyInfo);
// Decrypt the Hash using our Key
IBuffer result = CryptographicEngine.Decrypt(key, data, null);
Debug.WriteLine(result.ToString());
//Compare the two hashes
if (data == result) {
//Hash is verified!
}
Unfortunately when reaching the Decrypt method I get a NotImplementedException with error
The method or operation is not implemented
I researched online and I understand what needs to happen in theory but I don't know how to debug this further. What can I try?
Although both called PKCS#1 v1.5 padding, the padding for signature generation and encryption is not identical, see RFC 3447 for more details.
If you look at the RsaPkcs1 property you can see it is aimed at encryption:
Use the string retrieved by this property to set the asymmetric algorithm name when you call the OpenAlgorithm method. The string represents an RSA public key algorithm that uses PKCS1 to pad the plaintext. No hash algorithm is used.
As I don't see any option for "raw RSA", i.e. RSA without padding, it seems you are only able to verify your signature. However, RSA decryption expects an RSA private key. It's very likely that you get the error because of this: if you try and decrypt with a public key it will fail.
If you want to precompute the hash you can use VerifySignatureWithHashInput.
For other functionality you may have to use e.g. the C# lightweight API of Bouncy Castle. In the end you don't need platform provided cryptography to verify a signature.
I am writing an application where I need to encrypt, sign and wrap some content into a PKCS7/CMS structure. I am using OpenSSL.NET for the task (Wrapper for .NET).
I don't have much yet, I have successfully encrypted some data but
RSA toServer = cert.Certificate.PublicKey.GetRSA();
RSA fromClient = cert.Certificate.PublicKey.GetRSA();
byte[] cipherText = toServer.PublicEncrypt(Encoding.UTF8.GetBytes("Hello World!"), RSA.Padding.PKCS1);
byte[] plainText = fromClient.PrivateDecrypt(cipherText, RSA.Padding.PKCS1);
This works, it successfully encrypts and decrypts the data, but now I want to move further and implement PKCS7/CMS so that I have a standard format for my messages. I have found the below object that seem to point in the right direction but I fail to find some documentation on how to use it:
OpenSSL.X509.PKCS7 p7 = new OpenSSL.X509.PKCS7( ? );
Any suggestions or references to documentation are welcome.
I have seen question on signing and encrypting final mdm profile here:
iOS MDM profile signing, which certificate to use?
I am using Bouncy Castle library for encryption. Currently I am stuck while encrypting the final profile using the scep identitiy certificate.
I am facing the following issue.
The public key retrieved from with scep response certificate is not 16byte(128 bit) so encryption is failing with a message Key should be 128 bit.
If I can change the public key to 16byte using the following code the device throws invalid profile dailog.
public static string getKeyMessageDigest(string key)
{
byte[] ByteData = Encoding.UTF8.GetBytes(key);
//MD5 creating MD5 object.
MD5 oMd5 = MD5.Create();
byte[] HashData = oMd5.ComputeHash(ByteData);
//convert byte array to hex format
StringBuilder oSb = new StringBuilder();
for (int x = 0; x < HashData.Length; x++)
{
//hexadecimal string value
oSb.Append(HashData[x].ToString("x2"));
}
return Convert.ToString(oSb);
}
Can some one help me with some blog or sample code to encrypt the profile? Appreciate your help.
I had a similar problem. PFB the working code that I'm using to encrypt now. I'm retrieving the signing certificate from the device response, retrieving the public key from it and using the same to encrypt.
byte[] request = StreamToByte(ResponseFromDevice);
var signer = new SignedCms();
signer.Decode(request);
X509Certificate2 certificate = signer.Certificates[0];
string xmlData = "payload string to encrypt";
Byte[] cleartextsbyte = UTF8Encoding.UTF8.GetBytes(xmlData);
ContentInfo contentinfo = new ContentInfo(cleartextsbyte);
EnvelopedCms envelopedCms = new EnvelopedCms(contentinfo);
CmsRecipient recipient = new CmsRecipient(certificate);
envelopedCms.Encrypt(recipient);
string data = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\"><plist version=\"1.0\"><dict><key>EncryptedPayloadContent</key><data>[ENCRYPTEDDATA]</data><key>PayloadDescription</key><string>For profile enrollment</string><key>PayloadDisplayName</key><string>ProfileName</string><key>PayloadIdentifier</key><string>YourIdentifier</string><key>PayloadOrganization</key><string>YourOrg</string><key>PayloadRemovalDisallowed</key><false/><key>PayloadType</key><string>Configuration</string><key>PayloadUUID</key><string>YourUDID/string><key>PayloadVersion</key><integer>1</integer></dict></plist>";
data = data.Replace("[ENCRYPTEDDATA]", Convert.ToBase64String(envelopedCms.Encode()));
HttpContext.Current.Response.Write(data);
WebOperationContext.Current.OutgoingResponse.ContentType = "application/x-apple-aspen-config";
WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.OK;
I answered in comments on your previous question:
"I would recommend to take a look on OS X Server MDM implementation.
Generally speaking to encrypt profile, as I remember you should use PKCS7 wrapping. So, you should look at this: http://www.cs.berkeley.edu/~jonah/bc/org/bouncycastle/jce/PKCS7SignedData.html
BTW. I would recommend to read up a little bit on cryptography, if you want to get general understanding. Very-very high level overview of your problem: you are trying to use RSA key directly to encrypt the data. However, it should be used to encrypt a symmetric key which in its turn is used to encrypt the data."
You can also take a look here:
PKCS#7 Encryption
Your code won't work, because it's
- not PKCS7
- you are trying to use MD5(public certificate key) which doesn't make any sense
I would really-really recommend to read again MDM documentation and something on cryptopraphy. It's quite easy to make it wrong (both non working or unsecure implementation).
In bouncycastle you have to encrypt it using CMSAlgorithm.DES_EDE3_CBC. Then signed the data as you done in the previous step. Make sure you Base64 encode the encrypted payload before signing.
We encrypt PDFs using AESManaged algorithm implemented in .NET framework. I used the example explained in here to implement C# code to encrypt the file. Now I need to decrypt that file using an iPhone application.(That is the requirement). So I use the this code to do that but decryption failed by returning an error.
'Error Domain=CommonCryptoErrorDomain Code=-4304 "Decode Error"
UserInfo=0x127356c0 {NSLocalizedFailureReason=Input data did not
decode or decrypt correctly, NSLocalizedDescription=Decode Error'
Can some one help me to resolve this issue.
We use 12345678 as encryption key.
Most likely the problem is in the deriving actual key from the password (12345678 cannot be the AES key directly - it is only 8 bytes).
Technically this should work though I've never tested it, both methods uses the same ad-hoc format.
Encrypt using my authenticated encryption example.
//use your secret data you want to encrypt instead.
String secretMessage = "Message";
var rnCryptorHeader = new Byte[]{
2, //RNCryptor Format version 2
0 //RNCryptor Uses password
};
//encryptedString is base64 encoded
var encryptedString = AESThenHMAC.SimpleEncryptWithPassword(secretMessage,
password:"1234567891011",
nonSecretPayload:rnCryptorHeader);
Then Decrypt using RNCryptor and NSData+Base64 for IOS
//This is the encrypted data passed from .net
NSString *encryptedString = #"AgE8C9E7gsfyOAmSotIOgyLQ0O6mdcuMXXjN/iZa3azym4KVWZAkfykIP6mqMt/qkpfftdB3XQhMkoxtQEM+rA0iHxOvZiNlmA2KJtg6BOnmlg==";
NSData *encryptedData = [NSData dataFromBase64String: encryptedString];
NSError *error;
NSData *decryptedData = [RNDecryptor decryptData:encryptedData
withPassword:#"1234567891011"
error:&error];
NSString *secretMessage = [[[NSString alloc] initWithData:decryptedData
encoding:NSUTF8StringEncoding] autorelease];
Since you aren't dealing with strings and are dealing with bytes directly, just remove the Base64 and utf8 encoding/decoding from this objective-c example and the linked c# example, once you are sure this is working.