Qt Cryptographic Architecture
Public Types | Signals | Public Member Functions | Friends | List of all members
QCA::SecureMessage Class Reference

#include <QtCrypto>

Collaboration diagram for QCA::SecureMessage:
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Public Types

enum  Error {
  ErrorPassphrase , ErrorFormat , ErrorSignerExpired , ErrorSignerInvalid ,
  ErrorEncryptExpired , ErrorEncryptUntrusted , ErrorEncryptInvalid , ErrorNeedCard ,
  ErrorCertKeyMismatch , ErrorUnknown , ErrorSignerRevoked , ErrorSignatureExpired ,
  ErrorEncryptRevoked
}
 
enum  Format { Binary , Ascii }
 
enum  SignMode { Message , Clearsign , Detached }
 
enum  Type { OpenPGP , CMS }
 

Signals

void bytesWritten (int bytes)
 
void finished ()
 
void readyRead ()
 

Public Member Functions

bool bundleSignerEnabled () const
 
int bytesAvailable () const
 
bool canClearsign () const
 
bool canSignAndEncrypt () const
 
bool canSignMultiple () const
 
QString diagnosticText () const
 
void end ()
 
Error errorCode () const
 
Format format () const
 
QString hashName () const
 
QByteArray read ()
 
SecureMessageKeyList recipientKeys () const
 
void reset ()
 
 SecureMessage (SecureMessageSystem *system)
 
void setBundleSignerEnabled (bool b)
 
void setFormat (Format f)
 
void setRecipient (const SecureMessageKey &key)
 
void setRecipients (const SecureMessageKeyList &keys)
 
void setSigner (const SecureMessageKey &key)
 
void setSigners (const SecureMessageKeyList &keys)
 
void setSMIMEAttributesEnabled (bool b)
 
QByteArray signature () const
 
SecureMessageSignature signer () const
 
SecureMessageKeyList signerKeys () const
 
SecureMessageSignatureList signers () const
 
bool smimeAttributesEnabled () const
 
void startDecrypt ()
 
void startEncrypt ()
 
void startSign (SignMode m=Message)
 
void startSignAndEncrypt ()
 
void startVerify (const QByteArray &detachedSig=QByteArray())
 
bool success () const
 
Type type () const
 
void update (const QByteArray &in)
 
bool verifySuccess () const
 
bool waitForFinished (int msecs=30000)
 
bool wasSigned () const
 
- Public Member Functions inherited from QCA::Algorithm
 Algorithm (const Algorithm &from)
 
void change (const QString &type, const QString &provider)
 
void change (Provider::Context *c)
 
Provider::Contextcontext ()
 
const Provider::Contextcontext () const
 
Algorithmoperator= (const Algorithm &from)
 
Providerprovider () const
 
Provider::ContexttakeContext ()
 
QString type () const
 

Friends

class Private
 

Additional Inherited Members

- Protected Member Functions inherited from QCA::Algorithm
 Algorithm ()
 
 Algorithm (const QString &type, const QString &provider)
 

Detailed Description

Class representing a secure message.

SecureMessage presents a unified interface for working with both OpenPGP and CMS (S/MIME) messages. Prepare the object by calling setFormat(), setRecipient(), and setSigner() as necessary, and then begin the operation by calling an appropriate 'start' function, such as startSign().

Here is an example of how to perform a Clearsign operation using PGP:

// first make the SecureMessageKey
PGPKey myPGPKey = getSecretKeyFromSomewhere();
key.setPGPSecretKey(myPGPKey);
// our data to sign
QByteArray plain = "Hello, world";
// let's do it
OpenPGP pgp;
SecureMessage msg(&pgp);
msg.setSigner(key);
msg.startSign(SecureMessage::Clearsign);
msg.update(plain);
msg.end();
msg.waitForFinished(-1);
if(msg.success())
{
QByteArray result = msg.read();
// result now contains the clearsign text data
}
else
{
// error
...
}
Pretty Good Privacy messaging system.
Definition qca_securemessage.h:840
Pretty Good Privacy key.
Definition qca_cert.h:2407
Key for SecureMessage system.
Definition qca_securemessage.h:55
void setPGPSecretKey(const PGPKey &sec)
Set the private key part of a PGP key.
Class representing a secure message.
Definition qca_securemessage.h:320
@ Clearsign
the message is clear signed
Definition qca_securemessage.h:338

Performing a CMS sign operation is similar. Simply set up the SecureMessageKey with a Certificate instead of a PGPKey, and operate on a CMS object instead of an OpenPGP object.

See also
SecureMessageKey
SecureMessageSignature
OpenPGP
CMS
Examples
publickeyexample.cpp.

Member Enumeration Documentation

◆ Type

The type of secure message.

Enumerator
OpenPGP 

a Pretty Good Privacy message

CMS 

a Cryptographic Message Syntax message

◆ SignMode

The type of message signature.

Enumerator
Message 

the message includes the signature

Clearsign 

the message is clear signed

Detached 

the signature is detached

◆ Format

Formats for secure messages.

Enumerator
Binary 

DER/binary.

Ascii 

PEM/ascii-armored.

◆ Error

Errors for secure messages.

Enumerator
ErrorPassphrase 

passphrase was either wrong or not provided

ErrorFormat 

input format was bad

ErrorSignerExpired 

signing key is expired

ErrorSignerInvalid 

signing key is invalid in some way

ErrorEncryptExpired 

encrypting key is expired

ErrorEncryptUntrusted 

encrypting key is untrusted

ErrorEncryptInvalid 

encrypting key is invalid in some way

ErrorNeedCard 

pgp card is missing

ErrorCertKeyMismatch 

certificate and private key don't match

ErrorUnknown 

other error

ErrorSignerRevoked 

signing key is revoked

ErrorSignatureExpired 

signature is expired

ErrorEncryptRevoked 

encrypting key is revoked

Constructor & Destructor Documentation

◆ SecureMessage()

QCA::SecureMessage::SecureMessage ( SecureMessageSystem system)

Create a new secure message.

This constructor uses an existing SecureMessageSystem object (for example, an OpenPGP or CMS object) to generate a specific kind of secure message.

Parameters
systema pre-existing and configured SecureMessageSystem object

Member Function Documentation

◆ type()

Type QCA::SecureMessage::type ( ) const

The Type of secure message.

◆ canSignMultiple()

bool QCA::SecureMessage::canSignMultiple ( ) const

Test if the message type supports multiple (parallel) signatures.

Returns
true if the secure message support multiple parallel signatures
Note
PGP cannot do this - it is primarily a CMS feature

◆ canClearsign()

bool QCA::SecureMessage::canClearsign ( ) const

True if the SecureMessageSystem can clearsign messages.

Note
CMS cannot clearsign - this is normally only available for PGP

◆ canSignAndEncrypt()

bool QCA::SecureMessage::canSignAndEncrypt ( ) const

True if the SecureMessageSystem can both sign and encrypt (in the same operation).

Note
CMS cannot do an integrated sign/encrypt - this is normally only available for PGP. You can do separate signing and encrypting operations on the same message with CMS though.

◆ reset()

void QCA::SecureMessage::reset ( )

Reset the object state to that of original construction.

Now a new operation can be performed immediately.

◆ bundleSignerEnabled()

bool QCA::SecureMessage::bundleSignerEnabled ( ) const

Returns true if bundling of the signer certificate chain is enabled.

◆ smimeAttributesEnabled()

bool QCA::SecureMessage::smimeAttributesEnabled ( ) const

Returns true if inclusion of S/MIME attributes is enabled.

◆ format()

Format QCA::SecureMessage::format ( ) const

Return the format type set for this message.

◆ recipientKeys()

SecureMessageKeyList QCA::SecureMessage::recipientKeys ( ) const

Return the recipient(s) set for this message with setRecipient() or setRecipients()

◆ signerKeys()

SecureMessageKeyList QCA::SecureMessage::signerKeys ( ) const

Return the signer(s) set for this message with setSigner() or setSigners()

◆ setBundleSignerEnabled()

void QCA::SecureMessage::setBundleSignerEnabled ( bool  b)

For CMS only, this will bundle the signer certificate chain into the message.

This allows a message to be verified on its own, without the need to have obtained the signer's certificate in advance. Email clients using S/MIME often bundle the signer, greatly simplifying key management.

This behavior is enabled by default.

Parameters
bwhether to bundle (if true) or not (false)

◆ setSMIMEAttributesEnabled()

void QCA::SecureMessage::setSMIMEAttributesEnabled ( bool  b)

For CMS only, this will put extra attributes into the message related to S/MIME, such as the preferred type of algorithm to use in replies.

The attributes used are decided by the provider.

This behavior is enabled by default.

Parameters
bwhether to embed extra attribues (if true) or not (false)

◆ setFormat()

void QCA::SecureMessage::setFormat ( Format  f)

Set the Format used for messages.

The default is Binary.

Parameters
fwhether to use Binary or Ascii

◆ setRecipient()

void QCA::SecureMessage::setRecipient ( const SecureMessageKey key)

Set the recipient for an encrypted message.

Parameters
keythe recipient's key
See also
setRecipients
Examples
publickeyexample.cpp.

◆ setRecipients()

void QCA::SecureMessage::setRecipients ( const SecureMessageKeyList keys)

Set the list of recipients for an encrypted message.

For a list with one item, this has the same effect as setRecipient.

Parameters
keysthe recipients' key
See also
setRecipient

◆ setSigner()

void QCA::SecureMessage::setSigner ( const SecureMessageKey key)

Set the signer for a signed message.

This is used for both creating signed messages as well as for verifying CMS messages that have no signer bundled.

Parameters
keythe key associated with the signer
See also
setSigners

◆ setSigners()

void QCA::SecureMessage::setSigners ( const SecureMessageKeyList keys)

Set the list of signers for a signed message.

This is used for both creating signed messages as well as for verifying CMS messages that have no signer bundled.

For a list with one item, this has the same effect as setSigner.

Parameters
keysthe key associated with the signer
See also
setSigner

◆ startEncrypt()

void QCA::SecureMessage::startEncrypt ( )
   Start an encryption operation

   You will normally use this with some code along
   these lines:
   \code

encryptingObj.startEncrypt(); encryptingObj.update(message); // perhaps some more update()s encryptingObj.end();

Each update() may (or may not) result in some encrypted data, as indicated by the readyRead() signal being emitted. Alternatively, you can wait until the whole message is available (using either waitForFinished(), or use the finished() signal. The encrypted message can then be read using the read() method.

Examples
publickeyexample.cpp.

◆ startDecrypt()

void QCA::SecureMessage::startDecrypt ( )
   Start an decryption operation

   You will normally use this with some code along
   these lines:
   \code

decryptingObj.startEncrypt(); decryptingObj.update(message); // perhaps some more update()s decryptingObj.end();

Each update() may (or may not) result in some decrypted data, as indicated by the readyRead() signal being emitted. Alternatively, you can wait until the whole message is available (using either waitForFinished(), or the finished() signal). The decrypted message can then be read using the read() method.

Note
If decrypted result is also signed (not for CMS), then the signature will be verified during this operation.

◆ startSign()

void QCA::SecureMessage::startSign ( SignMode  m = Message)
   Start a signing operation

   You will normally use this with some code along
   these lines:
   \code

signingObj.startSign(QCA::SecureMessage::Detached) signingObj.update(message); // perhaps some more update()s signingObj.end();

For Detached signatures, you won't get any results until the whole process is done - you either waitForFinished(), or use the finished() signal, to figure out when you can get the signature (using the signature() method, not using read()). For other formats, you can use the readyRead() signal to determine when there may be part of a signed message to read().

Parameters
mthe mode that will be used to generate the signature

◆ startVerify()

void QCA::SecureMessage::startVerify ( const QByteArray &  detachedSig = QByteArray())

Start a verification operation.

Parameters
detachedSigthe detached signature to verify. Do not pass a signature for other signature types.

◆ startSignAndEncrypt()

void QCA::SecureMessage::startSignAndEncrypt ( )

Start a combined signing and encrypting operation.

You use this in the same way as startEncrypt().

Note
This may not be possible (e.g. CMS cannot do this) - see canSignAndEncrypt() for a suitable test.

◆ update()

void QCA::SecureMessage::update ( const QByteArray &  in)

Process a message (or the next part of a message) in the current operation.

You need to have already set up the message (startEncrypt(), startDecrypt(), startSign(), startSignAndEncrypt() and startVerify()) before calling this method.

Parameters
inthe data to process
Examples
publickeyexample.cpp.

◆ read()

QByteArray QCA::SecureMessage::read ( )

Read the available data.

Note
For detached signatures, you don't get anything back using this method. Use signature() to get the detached signature().
Examples
publickeyexample.cpp.

◆ bytesAvailable()

int QCA::SecureMessage::bytesAvailable ( ) const

The number of bytes available to be read.

◆ end()

void QCA::SecureMessage::end ( )

Complete an operation.

You need to call this method after you have processed the message (which you pass in as the argument to update().

Note
the results of the operation are not available as soon as this method returns. You need to wait for the finished() signal, or use waitForFinished().
Examples
publickeyexample.cpp.

◆ waitForFinished()

bool QCA::SecureMessage::waitForFinished ( int  msecs = 30000)

Block until the operation (encryption, decryption, signing or verifying) completes.

Parameters
msecsthe number of milliseconds to wait for the operation to complete. Pass -1 to wait indefinitely.
Note
You should not use this in GUI applications where the blocking behaviour looks like a hung application. Instead, connect the finished() signal to a slot that handles the results.
This synchronous operation may require event handling, and so it must not be called from the same thread as an EventHandler.
Examples
publickeyexample.cpp.

◆ success()

bool QCA::SecureMessage::success ( ) const

Indicates whether or not the operation was successful or failed.

If this function returns false, then the reason for failure can be obtained with errorCode().

See also
errorCode
diagnosticText
Examples
publickeyexample.cpp.

◆ errorCode()

Error QCA::SecureMessage::errorCode ( ) const

Returns the failure code.

See also
success
diagnosticText
Examples
publickeyexample.cpp.

◆ signature()

QByteArray QCA::SecureMessage::signature ( ) const

The signature for the message.

This is only used for Detached signatures. For other message types, you get the message and signature together using read().

◆ hashName()

QString QCA::SecureMessage::hashName ( ) const

The name of the hash used for the signature process.

◆ wasSigned()

bool QCA::SecureMessage::wasSigned ( ) const

Test if the message was signed.

This is true for OpenPGP if the decrypted message was also signed.

Returns
true if the message was signed.

◆ verifySuccess()

bool QCA::SecureMessage::verifySuccess ( ) const

Verify that the message signature is correct.

Returns
true if the signature is valid for the message, otherwise return false

◆ signer()

SecureMessageSignature QCA::SecureMessage::signer ( ) const

Information on the signer for the message.

◆ signers()

SecureMessageSignatureList QCA::SecureMessage::signers ( ) const

Information on the signers for the message.

This is only meaningful if the message type supports multiple signatures (see canSignMultiple() for a suitable test).

◆ diagnosticText()

QString QCA::SecureMessage::diagnosticText ( ) const

Returns a log of technical information about the operation, which may be useful for presenting to the user in an advanced error dialog.

◆ readyRead

void QCA::SecureMessage::readyRead ( )
signal

This signal is emitted when there is some data to read.

Typically you connect this signal to a slot that does a read() of the available data.

Note
This signal does not mean that the processing of a message is necessarily complete - see finished().

◆ bytesWritten

void QCA::SecureMessage::bytesWritten ( int  bytes)
signal

This signal is emitted when data has been accepted by the message processor.

Parameters
bytesthe number of bytes written

◆ finished

void QCA::SecureMessage::finished ( )
signal

This signal is emitted when the message is fully processed.


The documentation for this class was generated from the following file: