(JavaScript) Decrypt MIME using RSAES-OAEP with SHA256 and AES-128 content encryption

Demonstrates how to decrypt MIME what was encrypted with RSAES-OAEP with SHA256 and AES-128 content encryption.

In actuality, we don't really need to know in advance the various algorithms used to encrypt the MIME. When decrypting, the information about the algorithms required are embedded in the PCKS7 message itself, and this tells a decryptor what it should use.

Note: This example requires Chilkat v9.5.0.67 or greater.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

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

// We begin with this encrypted MIME:

// Content-Type: application/x-pkcs7-mime; name="smime.p7m"; smime-type="enveloped-data"
// someHeader1: Some value 1
// someHeader2: Some value 2
// Content-Disposition: attachment; filename="smime.p7m"
// Content-Transfer-Encoding: base64
// 
// MIIDvAYJKoZIhvcNAQcDoIIDrTCCA6kCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw
// CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ
// dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP
// oA0wCwYJYIZIAWUDBAIBBIIBAFaUL1ga1bOrdqYKcMm+FHUacBvzfBxk0fnPA0AMBdN8BvTWT3CN
// YuqBhjOGyq0FpYD9pVZybUuFMCVsVyIW2O62HnsOK58YaPEUUcdH2sI+yjqX9UAn0P0nVDSsVdeK
// W8x9kMfZg+3UP+y1q+lu7VRJO3f2C9oLQpTkc4VW4n7UOcUI0waykLCjCTL8lFDb7/J3GeuMKyhH
// 5riNz50kpbzqn7m2Ks9yA+QmcTdXclclGFr2vwEUFzSdT2pxh/vaUrogCxkYWbQ2eV7vZg6O4kV0
// aqHBqySkPTAzHKiHH8K8GVdlTuJ8350CpICa4T8w7/Ht5I7dyOPPKy4C+rVtrvcwggH+BgkqhkiG
// 9w0BBwEwHQYJYIZIAWUDBAECBBDTC2WNBN+z2I47/4Feu9YqgIIB0MZvl3nC/q/Wzil6HtfQTr12
// Q5moHY+ORzAa1P9XvX2ZUFhW530mV395mQw/A4o4ekmX9eRPEZquYzZPLT8hNeZIuNdhpcSQUmad
// rKnKkR0wKJ3jJ3LhOIohVBQSYs8kVDZKq6lJBIznlsurFelZoNEhyRschhteDZx5rb7fCe8c2+/O
// DHxaqaHCAzm/Bd7kcg6FFfuTZy3tu0PgP5IsXN4OFA3kkvwjAs4XsVS8jdIcmDNBkYieE8WmJOIm
// Mz7mh/CHWLgWfGKa0Dkb9RcbFgLwYNT3GzuXFw9XPbKkEZjEAtJajWbN6P0WQl96YYd9qZxUpGxZ
// zjTHEYzViUdUXolfpLufttrRXyxN1RFWhNFMFbv66xYqklMSgpdM/Mbk+EuvX6eXayDPvDBpfYMw
// NoRAzv1Ony2c0ez9rBemJICicxAzpuvHbRxdjYs63Dnv+TYgpBK12AxWWpPIjXvw0WQKgTC3Tg8s
// EnuGhpENqso/clJBEBSn4+2WhYtYbdI5sVme67lvqQl1Xxy3r18SWaQbyDOwgYi1E+54lMDOxMy0
// y0FPHk5pP45DnXWj+XORPp5LhuZr5mf62YOXSSUwR5P0cXy4Rc+pN5lhRQPCf5z2

var sb = new CkStringBuilder();
var bCrlf = true;
sb.AppendLine("Content-Type: application/x-pkcs7-mime; name=\"smime.p7m\"; smime-type=\"enveloped-data\"",bCrlf);
sb.AppendLine("someHeader1: Some value 1",bCrlf);
sb.AppendLine("someHeader2: Some value 2",bCrlf);
sb.AppendLine("Content-Disposition: attachment; filename=\"smime.p7m\"",bCrlf);
sb.AppendLine("Content-Transfer-Encoding: base64",bCrlf);
sb.AppendLine("",bCrlf);
sb.AppendLine("MIIDvAYJKoZIhvcNAQcDoIIDrTCCA6kCAQAxggGgMIIBnAIBADB1MGgxCzAJBgNVBAYTAlVTMQsw",bCrlf);
sb.AppendLine("CQYDVQQIDAJJTDEQMA4GA1UEBwwHV2hlYXRvbjEhMB8GA1UECgwYSW50ZXJuZXQgV2lkZ2l0cyBQ",bCrlf);
sb.AppendLine("dHkgTHRkMRcwFQYDVQQDDA5DaGlsa2F0V2lkZ2V0cwIJAMRwugDmvniwMBwGCSqGSIb3DQEBBzAP",bCrlf);
sb.AppendLine("oA0wCwYJYIZIAWUDBAIBBIIBAFaUL1ga1bOrdqYKcMm+FHUacBvzfBxk0fnPA0AMBdN8BvTWT3CN",bCrlf);
sb.AppendLine("YuqBhjOGyq0FpYD9pVZybUuFMCVsVyIW2O62HnsOK58YaPEUUcdH2sI+yjqX9UAn0P0nVDSsVdeK",bCrlf);
sb.AppendLine("W8x9kMfZg+3UP+y1q+lu7VRJO3f2C9oLQpTkc4VW4n7UOcUI0waykLCjCTL8lFDb7/J3GeuMKyhH",bCrlf);
sb.AppendLine("5riNz50kpbzqn7m2Ks9yA+QmcTdXclclGFr2vwEUFzSdT2pxh/vaUrogCxkYWbQ2eV7vZg6O4kV0",bCrlf);
sb.AppendLine("aqHBqySkPTAzHKiHH8K8GVdlTuJ8350CpICa4T8w7/Ht5I7dyOPPKy4C+rVtrvcwggH+BgkqhkiG",bCrlf);
sb.AppendLine("9w0BBwEwHQYJYIZIAWUDBAECBBDTC2WNBN+z2I47/4Feu9YqgIIB0MZvl3nC/q/Wzil6HtfQTr12",bCrlf);
sb.AppendLine("Q5moHY+ORzAa1P9XvX2ZUFhW530mV395mQw/A4o4ekmX9eRPEZquYzZPLT8hNeZIuNdhpcSQUmad",bCrlf);
sb.AppendLine("rKnKkR0wKJ3jJ3LhOIohVBQSYs8kVDZKq6lJBIznlsurFelZoNEhyRschhteDZx5rb7fCe8c2+/O",bCrlf);
sb.AppendLine("DHxaqaHCAzm/Bd7kcg6FFfuTZy3tu0PgP5IsXN4OFA3kkvwjAs4XsVS8jdIcmDNBkYieE8WmJOIm",bCrlf);
sb.AppendLine("Mz7mh/CHWLgWfGKa0Dkb9RcbFgLwYNT3GzuXFw9XPbKkEZjEAtJajWbN6P0WQl96YYd9qZxUpGxZ",bCrlf);
sb.AppendLine("zjTHEYzViUdUXolfpLufttrRXyxN1RFWhNFMFbv66xYqklMSgpdM/Mbk+EuvX6eXayDPvDBpfYMw",bCrlf);
sb.AppendLine("NoRAzv1Ony2c0ez9rBemJICicxAzpuvHbRxdjYs63Dnv+TYgpBK12AxWWpPIjXvw0WQKgTC3Tg8s",bCrlf);
sb.AppendLine("EnuGhpENqso/clJBEBSn4+2WhYtYbdI5sVme67lvqQl1Xxy3r18SWaQbyDOwgYi1E+54lMDOxMy0",bCrlf);
sb.AppendLine("y0FPHk5pP45DnXWj+XORPp5LhuZr5mf62YOXSSUwR5P0cXy4Rc+pN5lhRQPCf5z2",bCrlf);

// Load the encrypted MIME into the MIME object.
var mime = new CkMime();
mime.LoadMimeSb(sb);

// Provide the required cert + private key from a PFX (.pfx/.p12) file.
success = mime.AddPfxSourceFile("qa_data/rsaes-oaep/cert_plus_privatekey.pfx","PFX_PASSWORD");
if (success !== true) {
    console.log(mime.LastErrorText);
    return;
}

// Decrypt.
success = mime.Decrypt();
if (success !== true) {
    console.log(mime.LastErrorText);
    return;
}

// Examine the decrypted MIME.
console.log(mime.GetMime());
console.log("Decrypt test 1 succeeded.");

// -----------------------------------------------------------
// Now let's decrypt another way..
// We have the same cert and private key in PEM files..

var cert = new CkCert();
success = cert.LoadFromFile("qa_data/rsaes-oaep/cert.pem");

var privKey = new CkPrivateKey();
success = privKey.LoadPemFile("qa_data/rsaes-oaep/privatekey.pem");

// Decrypt using the cert + private key
var mime2 = new CkMime();
mime2.LoadMimeSb(sb);

success = mime2.Decrypt2(cert,privKey);
if (success !== true) {
    console.log(mime2.LastErrorText);
    return;
}

// Examine the decrypted MIME.
console.log(mime2.GetMime());
console.log("Decrypt test 2 succeeded.");