C# Requires Chilkat v11.0.0+

S/MIME Decrypt, Verify Signatures, and Get Algorithms

Demonstrates how to get the digest and encryption algorithms encountered when verifying signatures and decrypting S/MIME. C#

bool success = false;

//  This requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

Chilkat.Mime mime = new Chilkat.Mime();

success = mime.LoadMimeFile("qa_data/smime/signed_and_encrypted_mime.txt");
if (success == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

success = mime.AddPfxSourceFile("qa_data/smime/secret.pfx","secret");
if (success == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

//  Call UnwrapSecurity to decrypt and verify signatures..
success = mime.UnwrapSecurity();
if (success == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

//  The information about what digest and encryption algorithms were encountered are
//  in the last JSON data.  This is JSON that contains various pieces of information 
//  depending on the method call.  
Chilkat.JsonObject json = new Chilkat.JsonObject();
mime.GetLastJsonData(json);

json.EmitCompact = false;

Debug.WriteLine(json.Emit());

//  The JSON contains information such as the following:

//  	{
//  	  "pkcs7": {
//  	    "decrypt": [
//  	      {
//  	        "alg": {
//  	          "name": "aes",
//  	          "keySize": 128
//  	        }
//  	      }
//  	    ],
//  	    "verify": {
//  	      "digestAlgorithms": [
//  	        "sha256"
//  	      ]
//  	    }
//  	  }
//  	}

//  To iterate over digest and encryption algorithms:
int numEncAlgs = json.SizeOfArray("pkcs7.decrypt");
int i = 0;
while (i < numEncAlgs) {
    json.I = i;
    Debug.WriteLine("encAlg = " + json.StringOf("pkcs7.decrypt[i].alg.name"));
    Debug.WriteLine("keySize = " + Convert.ToString(json.IntOf("pkcs7.decrypt[i].alg.keySize")));
    i = i + 1;
}

int numDigestAlgs = json.SizeOfArray("pkcs7.verify.digestAlgorithms");
i = 0;
while (i < numDigestAlgs) {
    json.I = i;
    Debug.WriteLine("digest = " + json.StringOf("pkcs7.verify.digestAlgorithms[i]"));
    i = i + 1;
}