iaik.smime

Class SMimeMailer

java.lang.Object

iaik.utils.SmtpMailer

iaik.smime.SMimeMailer

public class SMimeMailer
extends iaik.utils.SmtpMailer

Simple S/MIME mailing tool based on the IAIK-JCE SmtpMailer utility. It may be used for sending signed, encrypted, or signed and encrypted text mails without usage of the Jakarta Mail API. Only the application/pkcs7-mime type is used for both, signed (smime-type "signed-data") or encrypted (smime-type "enveloped-data") mails.

The following example shows how to use this class for sending a

• signed
• encrypted
• signed and encrypted

S/MIME message:

• Sending of a signed message

       // mailhost
       String mailhost = "mailhost";
       // sender name
       String senderName = "John Doe";
       // sender address
       String senderAddress = "John.Doe@test.at";
       // certificate list to be included into the SignedData
       X509Certificate[] certificates = ...;
       // certificate of the signer
       X509Certificate senderCertificate = ...;
       // encryption cert of sender (if to be included into the certificates field)
       X509Certificate encryptionCertOfSender = ...;
       // the private signer key
       PrivateKey signerKey = ...;
       // create a SMimeMailer
       SMimeMailer mailer = new SMimeMailer(mailhost, SMimeMailer.SIGNED);
       // set subject header
       mailer.setSubject("...");
       // sending date is now
       mailer.addDate();
       // set sender (signer) information
       mailer.setFrom(senderName, 
                      senderAddress, 
                      certificates, 
                      signerCertificate,
                      encryptionCertOfSender,
                      null, 
                      signerKey, 
                      AlgorithmID.sha256,
                      AlgorithmID.rsaEncryption);
       // set recipient name and recipient address
       String recipientName = ...;
       String recipientAddress = ...;
       mailer.addTo(recipientName, recipientAddress);
       // set the message text
       mailer.addText(...);
       // send mail
       mailer.sendMail();
       

• Sending of an encrypted message

       // mailhost
       String mailhost = "mailhost";
       // sender name
       String senderName = "John Doe";
       // sender address
       String senderAddress = "John.Doe@test.at";
       // encryption cert of sender (to encrypt the symmetric key for the sender, too)
       X509Certificate encryptionCertOfSender = ...;
       // key encryption algorithm for encrypting the symmetric key for the sender 
       AlgorithmID keyEncAlgOfSender = AlgorithmID.rsaEncryption;
       // create a SMimeMailer
       SMimeMailer mailer = new SMimeMailer(mailhost, SMimeMailer.ENCRYPTED);
       // set subject header
       mailer.setSubject("...");
       // sending date is now
       mailer.addDate();
       // set sender information
       mailer.setFrom(senderName, senderAddress, encryptionCertOfSender, keyEncAlgOfSender); 
       // encryption cert of the recipient
       X509Certificate recipientCert = ...;
       // key encryption algorithm for encrypting the symmetric key for the recipient
       AlgorithmID keyEncAlgOfRecipient = AlgorithmID.rsaEncryption;
       // set recipient information
       String recipientName = ...;
       String recipientAddress = ...;
       mailer.addTo(recipientName, recipientAddress, recipientCert, keyEncAlgOfRecipient);
       // set encryption algorithm information
       AlgorithmID contentEA =  (AlgorithmID)AlgorithmID.aes256_CBC.clone();
       int keyLength = 256;
       mailer.setEncryption(contentEA, keyLength);
       // set the message text
       mailer.addText(...);
       // send mail
       mailer.sendMail();
       

• Sending of a signed and encrypted message

       // mailhost
       String mailhost = "mailhost";
       // sender name
       String senderName = "John Doe";
       // sender address
       String senderAddress = "John.Doe@test.at";
       // certificate list to be included into the SignedData
       X509Certificate[] certificates = ...;
       // certificate of the signer
       X509Certificate signerCertificate = ...;
       // encryption cert of signer (to encrypt the symmetric key for the sender, too)
       X509Certificate encryptionCertOfSender = ...;
       // key encryption algorithm for encrypting the symmetric key for the sender (signer)
       AlgorithmID keyEncAlgOfSender = AlgorithmID.rsaEncryption;
       // the private signer key
       PrivateKey signerKey = ...;
       // create a SMimeMailer
       SMimeMailer mailer = new SMimeMailer(mailhost, SMimeMailer.SIGNED_AND_ENCRYPTED);
       // set subject header
       mailer.setSubject("...");
       // sending date is now
       mailer.addDate();
       // set sender (signer) information
       mailer.setFrom(senderName, 
                      senderAddress, 
                      certificates, 
                      signerCertificate,
                      encryptionCertOfSender,
                      keyEncAlgOfSender, 
                      signerKey, 
                      AlgorithmID.sha256,
                      AlgorithmID.rsaEncryption);
       // encryption cert of the recipient
       X509Certificate recipientCert = ...;
       // key encryption algorithm for encrypting the symmetric key for the recipient
       AlgorithmID keyEncAlgOfRecipient = AlgorithmID.rsaEncryption;
       // set recipient information
       String recipientName = ...;
       String recipientAddress = ...;
       mailer.addTo(recipientName, recipientAddress, recipientCert, keyEncAlgOfRecipient);
       // set encryption algorithm information
       AlgorithmID contentEA =  (AlgorithmID)AlgorithmID.aes256_CBC.clone();
       int keyLength = 256;
       mailer.setEncryption(contentEA, keyLength);
       // set the message text
       mailer.addText(...);
       // send mail
       mailer.sendMail();
       

Field Summary

Fields

Modifier and Type	Field and Description
static int	ENCRYPTED Value for creating encrypted S/MIME messages.
static int	SIGNED Value for creating signed S/MIME messages.
static int	SIGNED_AND_ENCRYPTED Value for creating signed and encrypted S/MIME messages.

Constructor Summary

Constructors

Constructor and Description
SMimeMailer(java.lang.String mailhost, int mode) Creates a new SMimeMailer.

Method Summary

Modifier and Type	Method and Description
void	addAdditionalField(java.lang.String line) Sets any additional field according to RFC822.
void	addBcc(java.lang.String realName, java.lang.String emailAddress, iaik.x509.X509Certificate recipientCert, iaik.asn1.structures.AlgorithmID keyEncAlg) Adds one receiver (Bcc: field) of the S/MIME email message.
void	addCc(java.lang.String realName, java.lang.String emailAddress, iaik.x509.X509Certificate recipientCert, iaik.asn1.structures.AlgorithmID keyEncAlg) Adds one receiver (Cc: field) of the S/MIME email message.
void	addDate() Sets the "Date:" field to the current date.
void	addDate(java.util.Date date) Sets the "Date:" field to the specified date.
void	addTo(java.lang.String realName, java.lang.String emailAddress, iaik.x509.X509Certificate recipientCert, iaik.asn1.structures.AlgorithmID keyEncAlg) Adds one receiver (To: field) of the S/MIME email message.
boolean	sendMail() Encrypt and send the mail that was just created.
void	setEncryption(iaik.asn1.structures.AlgorithmID contentEncAlg, int keyLength) Sets the symmetric algorithm for encrypting the message.
void	setFrom(java.lang.String realName, java.lang.String emailAddress, iaik.x509.X509Certificate[] certificates, iaik.x509.X509Certificate signerCertificate, iaik.x509.X509Certificate encryptionCertOfSender, iaik.asn1.structures.AlgorithmID keyEncAlg, java.security.PrivateKey signerKey, iaik.asn1.structures.AlgorithmID hashAlgorithm, iaik.asn1.structures.AlgorithmID signatureAlgorithm) Sets the from field of the S/MIME email message.
void	setFrom(java.lang.String realName, java.lang.String emailAddress, iaik.x509.X509Certificate senderCert, iaik.asn1.structures.AlgorithmID keyEncAlg) Sets the from field of the S/MIME email message.
void	setSecureRandom(java.security.SecureRandom random) Sets the source of randomness for the key generation.
java.lang.String	toString() Returns a string representation of this SMimeMailer.

Methods inherited from class iaik.utils.SmtpMailer

addBcc, addCc, addText, addTo, checkResponse, send, sendCommands, setDebug, setFrom, setLineSeparator, setReplyTo, setSender, setSubject, setText, setVerify, writeBody, writeHeaders

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ENCRYPTED

public static final int ENCRYPTED

Value for creating encrypted S/MIME messages.

See Also:

Constant Field Values

SIGNED

public static final int SIGNED

Value for creating signed S/MIME messages.

See Also:

Constant Field Values

SIGNED_AND_ENCRYPTED

public static final int SIGNED_AND_ENCRYPTED

Value for creating signed and encrypted S/MIME messages.

See Also:

Constant Field Values

Constructor Detail

SMimeMailer

public SMimeMailer(java.lang.String mailhost,
                   int mode)

Creates a new SMimeMailer.

Parameters:

mailhost - the name of the SMTP server (e.g. "mailhost.domain.com")

mode - the S/MIME message mode (ENCRYPTED, SIGNED, or SIGNED_AND_ENCRYPTED)

Method Detail

setFrom

public void setFrom(java.lang.String realName,
                    java.lang.String emailAddress,
                    iaik.x509.X509Certificate senderCert,
                    iaik.asn1.structures.AlgorithmID keyEncAlg)

Sets the from field of the S/MIME email message. Use this method to set the from field for sending an encrypted message where the sender also should be able to decrypt the encrypted message. If the sender doesn't need the possibility to encrypt the message you can use the method void setFrom(String realName, String emailAddress); from the superclass SmtpMailer.

Parameters:

realName - the real name of the sender (e.g. "John Doe")

emailAddress - the email address of the sender (e.g. "John.Doe@test.at")

senderCert - the certificate of the sender

keyEncAlg - the algorithm used to encrypt the temporary symmetric key for the sender

setFrom

public void setFrom(java.lang.String realName,
                    java.lang.String emailAddress,
                    iaik.x509.X509Certificate[] certificates,
                    iaik.x509.X509Certificate signerCertificate,
                    iaik.x509.X509Certificate encryptionCertOfSender,
                    iaik.asn1.structures.AlgorithmID keyEncAlg,
                    java.security.PrivateKey signerKey,
                    iaik.asn1.structures.AlgorithmID hashAlgorithm,
                    iaik.asn1.structures.AlgorithmID signatureAlgorithm)
             throws SMimeException

Sets the from field of the S/MIME email message. Use this method to set the from field for sending a signed or signed and encrypted message. If the message should be encrypted, too, and the sender should also be able to read (decrypt) the message, the encryption certificate of the sender and the key encryption algorithm (to be used to encrypt the temporary content encryption key) has to be not null.

Parameters:

realName - the real name of the sender (e.g. "John Doe")

emailAddress - the email address of the sender (e.g. "John.Doe@test.at")

certificates - the certificates to be set for the SignedData signature object (may also contain the encryption cert of the sender)

signerCertificate - the certificate of the signer (sender)

encryptionCertOfSender - the encryption cert of the sender (if to be included into the certificates field and/or the message should be encrypted for the sender, too; otherwise null)

keyEncAlg - the algorithm used to encrypt the temporary symmetric key for the sender (if the message should be encrypted, too; otherwise null)

signerKey - the private key of the sender used for signing the message

hashAlgorithm - the hash algorithm to be use (e.g. AlgorithmID.sha256)

signatureAlgorithm - the signature algorithm to be used (e.g. AlgorithmID.rsaEncryption)

Throws:

SMimeException - if the signer setup fails

addTo

public void addTo(java.lang.String realName,
                  java.lang.String emailAddress,
                  iaik.x509.X509Certificate recipientCert,
                  iaik.asn1.structures.AlgorithmID keyEncAlg)

Adds one receiver (To: field) of the S/MIME email message.

Parameters:

realName - the real name of the sender (e.g. "John Doe")

emailAddress - the email address of the sender (e.g. "John.Doe@test.at")

recipientCert - the certificate of the sender

keyEncAlg - the algorithm used to encrypt the temporary symmetric key for a receiver

addCc

public void addCc(java.lang.String realName,
                  java.lang.String emailAddress,
                  iaik.x509.X509Certificate recipientCert,
                  iaik.asn1.structures.AlgorithmID keyEncAlg)

Adds one receiver (Cc: field) of the S/MIME email message.

Parameters:

realName - the real name of the sender (e.g. "John Doe")

emailAddress - the email address of the sender (e.g. "John.Doe@test.at")

recipientCert - the certificate of the sender

keyEncAlg - the algorithm used to encrypt the temporary symmetric key for a receiver

addBcc

public void addBcc(java.lang.String realName,
                   java.lang.String emailAddress,
                   iaik.x509.X509Certificate recipientCert,
                   iaik.asn1.structures.AlgorithmID keyEncAlg)

Adds one receiver (Bcc: field) of the S/MIME email message.

Parameters:

realName - the real name of the sender (e.g. "John Doe")

emailAddress - the email address of the sender (e.g. "John.Doe@test.at")

recipientCert - the certificate of the sender

keyEncAlg - the algorithm used to encrypt the temporary symmetric key for a receiver

addAdditionalField

public void addAdditionalField(java.lang.String line)

Sets any additional field according to RFC822. For example: "MIME-Version: 1.0". This method overwrites the corresponding method in SmtpMailer to ensure that this additional headers are also encrypted.

Overrides:

addAdditionalField in class iaik.utils.SmtpMailer

Parameters:

line - a complete line

addDate

public void addDate()

Sets the "Date:" field to the current date.

addDate

public void addDate(java.util.Date date)

Sets the "Date:" field to the specified date.

Parameters:

date - the date

setEncryption

public void setEncryption(iaik.asn1.structures.AlgorithmID contentEncAlg,
                          int keyLength)

Sets the symmetric algorithm for encrypting the message. For RC2 the key length in bits can be: 40, 64, 128. If the encryption algorithm is not RC2 this parameter is ignored.

Examples for possible encryption algorithms are:

• aes256_CBC (AES-256 in CBC mode)
• aes128_CBC (AES-128 in CBS mode)
• AlgorithmID.des_EDE3_CBC
• AlgorithmID.rc2_CBC
• AlgorithmID.des_CBC

Parameters:

contentEncAlg - the algorithm for encrypting the content

keyLength - the key length for RC2

setSecureRandom

public void setSecureRandom(java.security.SecureRandom random)

Sets the source of randomness for the key generation.

Parameters:

random - a random number generator

sendMail

public boolean sendMail()
                 throws iaik.utils.SmtpException

Encrypt and send the mail that was just created.

Overrides:

sendMail in class iaik.utils.SmtpMailer

Returns:

true if the response codes from the server were the expected (if verify is switched on), false otherwise

Throws:

iaik.utils.SmtpException - if there is a problem while sending the EMail

See Also:

SmtpMailer

toString

public java.lang.String toString()

Returns a string representation of this SMimeMailer.

Overrides:

toString in class iaik.utils.SmtpMailer

Returns:

the string representation