/* Add BC */
Security. AddProvider (new BouncyCastleProvider ()); 

String pkcs12Path="XXX. PFX"; 
String keyalias="XXXX"; 
String keyPwd="* * * * * *"; 
String smtpServer=xxx.xxx.com "; 
String emailAddress="xxx.xxx.com"; 
String emailPwd="XXXXX"; 

ArrayList ToAdd=new ArrayList<> (a); 
String path="[email protected]"; 
FileInputStream fi=new FileInputStream (path); 
CertificateFactory cf=CertificateFactory. GetInstance (" X. 509 ", "BC"); 
X509Certificate cert=(X509Certificate) cf. GenerateCertificate (fi); 
ToAdd. Add (new AddressInfo (" [email protected] ", cert)); 

Try {
MailcapCommandMap mailcap=(MailcapCommandMap) CommandMap. GetDefaultCommandMap (); 

Mailcap. AddMailcap (" application/pkcs7 - signature;; X - Java - content - handler=org. Bouncycastle. Mail. Smime. Handlers. Pkcs7_signature "); 
Mailcap. AddMailcap (" application/pkcs7 - mime;; X - Java - content - handler=org. Bouncycastle. Mail. Smime. Handlers. Pkcs7_mime "); 
Mailcap. AddMailcap (" application/x - pkcs7 - signature;; X - Java - content - handler=org. Bouncycastle. Mail. Smime. Handlers. X_pkcs7_signature "); 
Mailcap. AddMailcap (" application/x - pkcs7 - mime;; X - Java - content - handler=org. Bouncycastle. Mail. Smime. Handlers. X_pkcs7_mime "); 
Mailcap. AddMailcap (" multipart/signed;; X - Java - content - handler=org. Bouncycastle. Mail. Smime. Handlers. Multipart_signed "); 

CommandMap. SetDefaultCommandMap (mailcap); 

/* Open the keystore */
KeyStore KeyStore=KeyStore. GetInstance (" as PKCS12 ", "BC"); 
Keystore. Load (new FileInputStream (pkcs12Path), "". ToCharArray ()); 
Certificate chain []=keystore. GetCertificateChain (keyalias); 

/* Get the private key to sign the message with */
PrivateKey PrivateKey=(PrivateKey) keystore. GetKey (keyalias keyPwd. ToCharArray ()); 
If (privateKey==null) {
Throw new Exception (" always find a private key for alias: "+ keyalias); 
} 

/* Create the message to sign and encrypt */
The Properties of props=System. The getProperties (); 
Props. The put (mail. The SMTP. "the host", smtpServer); 
Props. The put (" mail. The SMTP auth ", "true"); 

The Session Session=Session. GetDefaultInstance (props, new MyAuthenticator (emailAddress, emailPwd)); 

The MimeMessage body=new MimeMessage (session); 
Body. SetFrom (new InternetAddress (emailAddress)); 
If (toAdd!=null) {
Body. AddRecipients (Message) RecipientType) TO the parseEmailAdd (toAdd)); 
} 
If (ccAdd!=null) {
Body. AddRecipients (Message. RecipientType. CC, parseEmailAdd (ccAdd)); 
} 
If (bccAdd!=null) {
Body. AddRecipients (Message. RecipientType. BCC, parseEmailAdd (bccAdd)); 
} 
Body. SetSubject (subject); 
Body. SetContent (textContent, "text/plain"); 
Body. The saveChanges (); 

/* Create the SMIMESignedGenerator */
SMIMECapabilityVector "capabilities=new SMIMECapabilityVector (); 
"Capabilities. AddCapability (SMIMECapability. DES_EDE3_CBC); 
"Capabilities. AddCapability (SMIMECapability rC2_CBC, 128); 
"Capabilities. AddCapability (SMIMECapability. DES_CBC); 

ASN1EncodableVector attributes=new ASN1EncodableVector (); 
Attributes. The add (new SMIMEEncryptionKeyPreferenceAttribute (new IssuerAndSerialNumber (new X500Name (((X509Certificate) chain [0]). GetIssuerDN (). The getName ()), 
((X509Certificate) chain [0]) getSerialNumber ()))); 
The attributes. The add (new SMIMECapabilitiesAttribute (" capabilities)); 

SMIMESignedGenerator signer=new SMIMESignedGenerator (); 
Signer. AddSignerInfoGenerator (new JcaSimpleSignerInfoGeneratorBuilder (.) setProvider (" BC "). SetSignedAttributeGenerator (new AttributeTable (attributes)) 
. Build (" DSA. "equals (privateKey. GetAlgorithm ())? "SHA1withDSA" : "MD5withRSA", privateKey, (X509Certificate) chain [0])); 

/* Add to the list of certs to the generator */
The List certList=new ArrayList (); 
CertList. Add (chain [0]); 
Store certs=new JcaCertStore (certList); 
Signer. AddCertificates (certs); 

/* Sign the message */
MimeMultipart mm=signer. The generate (body); 
The MimeMessage signedMessage=new MimeMessage (session); 

/* the Set all the original MIME headers in the signed message */
Enumeration headers=body. GetAllHeaderLines (); 
While (headers. HasMoreElements ()) {
SignedMessage. AddHeaderLine ((String) headers. NextElement ()); 
} 

/* Set the content of the signed message */
SignedMessage. SetContent (mm); 
SignedMessage. SaveChanges (); 

/* Create the encrypter */
SMIMEEnvelopedGenerator encrypter=new SMIMEEnvelopedGenerator (); 
AddRecipientInfoGenerator (encrypter toAdd);//
AddRecipientInfoGenerator (encrypter ccAdd); 
AddRecipientInfoGenerator (encrypter bccAdd); 

/* Encrypt the message */
MimeBodyPart encryptedPart=encrypter. Generate (signedMessage, new JceCMSContentEncryptorBuilder (CMSAlgorithm. RC2_CBC). SetProvider (" BC "). The build ()); 

/* 
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