(.NET Core C#) Extract PKCS7 from MIME and Decrypt

Extracts the base64-encoded PKCS7 body of a MIME message to a file, and then decrypts using Chilkat Crypt2.

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

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

bool success = mime.LoadMimeFile("c:/aaworkarea/EmailInBytes.txt");
if (success != true) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

success = mime.SaveBody("c:/aaworkarea/smime.p7m");
if (success != true) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

success = crypt.AddPfxSourceFile("c:/aaworkarea/my.pfx","pfxPassword");
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Indicate the public-key (PKCS7) encryption/decryption should be used:
crypt.CryptAlgorithm = "pki";

string inPath = "c:/aaworkarea/smime.p7m";
string outPath = "c:/aaworkarea/decrypted.dat";

success = crypt.CkDecryptFile(inPath,outPath);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

Debug.WriteLine("Success.");