(C#) FatturaPA XML Invoice Sign+Encrypt to P7M

Demonstrates how to create a CAdES BES signed + encrypted invoice.xml.p7m for the Italian FatturaPA exchange system.

Note: This example requires Chilkat v9.5.0.75 or greater.

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// Note: Requires Chilkat v9.5.0.75 or greater.

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

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

// Use a digital certificate and private key from a PFX file (.pfx or .p12).
string pfxPath = "qa_data/pfx/cert_test123.pfx";
string pfxPassword = "test123";

Chilkat.Cert cert = new Chilkat.Cert();
bool success = cert.LoadPfxFile(pfxPath,pfxPassword);
if (success != true) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

// Provide the signing cert (with associated private key).
success = crypt.SetSigningCert(cert);
if (success != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Indicate that SHA-256 should be used.
crypt.HashAlgorithm = "sha256";

// Specify the signed attributes to be included.
// (This is what makes it CAdES-BES compliant.)
Chilkat.JsonObject jsonSignedAttrs = new Chilkat.JsonObject();
jsonSignedAttrs.UpdateInt("contentType",1);
jsonSignedAttrs.UpdateInt("signingTime",1);
jsonSignedAttrs.UpdateInt("messageDigest",1);
jsonSignedAttrs.UpdateInt("signingCertificateV2",1);
crypt.SigningAttributes = jsonSignedAttrs.Emit();

string inFile = "qa_data/xml/IT01234567890_11002.xml";
string sigFile = "qa_data/fatturapa/signed.p7m";

// Create the CAdES-BES signature, which contains the original data.
success = crypt.CreateP7M(inFile,sigFile);
if (success == false) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Now we'll encrypt what was signed using FatturaPA's certificate (from a PEM file)
Chilkat.Cert encryptCert = new Chilkat.Cert();
success = encryptCert.LoadFromFile("qa_data/certs/fatturapa_cert.pem");
if (success != true) {
    Debug.WriteLine(encryptCert.LastErrorText);
    return;
}

crypt.CryptAlgorithm = "pki";

success = crypt.SetEncryptCert(encryptCert);
if (success != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Indicate the underlying bulk encryption algorithm to be used:
crypt.Pkcs7CryptAlg = "aes";
crypt.KeyLength = 128;

// There's one last option that could be set.  If is the RSA encryption encryption/padding scheme. 
// By default, RSAES_PKCS1-V1_5 is used.  If desired, the OaepPadding property could be set to true to
// use RSAES_OAEP.  (We'll leave it set at the default value of false)
crypt.OaepPadding = false;

// Everything is specified.  Encrypt the .p7m to create a new .p7m (which adds a layer of encryption around the opaque signature).
// The output is PKCS7 in binary DER format.
success = crypt.CkEncryptFile(sigFile,"qa_output/signed_and_encrypted.p7m");
if (success != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

Debug.WriteLine("Success.");