MessageDecryptor Class

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The MessageDecryptor class decrypts data that is stored in the PKCS#7 format.

Class Name

SecureBlackbox_MessageDecryptor

Procedural Interface

 secureblackbox_messagedecryptor_open();
 secureblackbox_messagedecryptor_close($res);
 secureblackbox_messagedecryptor_register_callback($res, $id, $function);
 secureblackbox_messagedecryptor_get_last_error($res);
 secureblackbox_messagedecryptor_get_last_error_code($res);
 secureblackbox_messagedecryptor_set($res, $id, $index, $value);
 secureblackbox_messagedecryptor_get($res, $id, $index);
 secureblackbox_messagedecryptor_do_checkencryptiontype($res);
 secureblackbox_messagedecryptor_do_config($res, $configurationstring);
 secureblackbox_messagedecryptor_do_decrypt($res);
 secureblackbox_messagedecryptor_do_doaction($res, $actionid, $actionparams);
 secureblackbox_messagedecryptor_do_reset($res);

Remarks

PKCS#7 (Public Key Cryptography Standard #7) is a common format used to store encrypted and signed data. It is used by a variety of protocols, including S/MIME and CMS.

MessageDecryptor is capable of decrypting encrypted PKCS#7 data stored in EnvelopedData (asymmetric encryption) and EncryptedData (symmetric encryption) subformats. RSA and ECDH key wrapping and all popular symmetric encryption algorithms are supported.

Setting up and using MessageDecryptor is easy:

• Set up your source and destination via InputFile (InputBytes) and OutputFile (OutputBytes) properties.
• For certificate-based (asymmetric) encryption, put the decryption certificate (with its private key included) to the Certificates collection.
• For key-based (symmetric) encryption, assign the symmetric key to Key property. Note: you can find out whether asymmetric or symmetric encryption was used on the input message using the CheckEncryptionType method.
• Call Decrypt to execute the operation.

Note that MessageDecryptor only works with binary PKCS#7-compliant encrypted messages. For processing encrypted S/MIME emails, see MailReader. For decrypting PGP messages, see PGPReader. For raw symmetric encryption, see SymmetricCrypto. For processing XML-ENC messages, see XMLDecryptor. MessageDecryptor decryptor = new MessageDecryptor(); // Select the file which contains the message that will be decrypted decryptor.setInputFile("encryptedMessage.bin"); // Select the file where the decrypted message will be written decryptor.setOutputFile("decryptedMessage.txt"); // Providing the certificate with its private key to decrypt data CertificateList certificateList = new CertificateList(); certificateList.add(new Certificate("cert.pfx","password")); decryptor.setCertificates(certificateList); decryptor.decrypt(); // Decrypt

Property List

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The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

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The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

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The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

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The following is a list of config settings for the class with short descriptions. Click on the links for further details.

CertificateIndex Property (SecureBlackbox_MessageDecryptor Class)

The index of certificate that was used to decrypt the message.

Object Oriented Interface

public function getCertificateIndex();

Procedural Interface

secureblackbox_messagedecryptor_get($res, 1 );

Default Value

-1

Remarks

This property contains the index of certificate (one of those residing in Certificates collection) that was used to decrypt the message.

This property is read-only.

Data Type

Integer

CertCount Property (SecureBlackbox_MessageDecryptor Class)

The number of records in the Cert arrays.

Object Oriented Interface

public function getCertCount();
public function setCertCount($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 2 );
secureblackbox_messagedecryptor_set($res, 2, $value );

Default Value

0

Remarks

This property controls the size of the following arrays:

• CertBytes
• CertHandle

The array indices start at 0 and end at CertCount - 1.

This property is not available at design time.

Data Type

Integer

CertBytes Property (SecureBlackbox_MessageDecryptor Class)

Returns the raw certificate data in DER format.

Object Oriented Interface

public function getCertBytes($certindex);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 3 , $certindex);

Remarks

Returns the raw certificate data in DER format.

The $certindex parameter specifies the index of the item in the array. The size of the array is controlled by the CertCount property.

This property is read-only and not available at design time.

Data Type

Byte Array

CertHandle Property (SecureBlackbox_MessageDecryptor Class)

Allows to get or set a 'handle', a unique identifier of the underlying property object.

Object Oriented Interface

public function getCertHandle($certindex);
public function setCertHandle($certindex, $value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 11 , $certindex);
secureblackbox_messagedecryptor_set($res, 11, $value , $certindex);

Default Value

0

Remarks

Allows to get or set a 'handle', a unique identifier of the underlying property object. Use this property to assign objects of the same type in a quicker manner, without copying them fieldwise.

When you pass a handle of one object to another, the source object is copied to the destination rather than assigned. It is safe to get rid of the original object after such operation. pdfSigner.setSigningCertHandle(certMgr.getCertHandle());

The $certindex parameter specifies the index of the item in the array. The size of the array is controlled by the CertCount property.

This property is not available at design time.

Data Type

Long64

EncryptionAlgorithm Property (SecureBlackbox_MessageDecryptor Class)

The symmetric cipher that was used to encrypt the data.

Object Oriented Interface

public function getEncryptionAlgorithm();

Procedural Interface

secureblackbox_messagedecryptor_get($res, 42 );

Default Value

''

Remarks

This property contains the symmetric algorithm that the creator had used to encrypt the message.

This property is read-only and not available at design time.

Data Type

String

EncryptionType Property (SecureBlackbox_MessageDecryptor Class)

Specifies the kind of encrypted message to create.

Object Oriented Interface

public function getEncryptionType();

Procedural Interface

secureblackbox_messagedecryptor_get($res, 43 );

Default Value

0

Remarks

Possible values:

This property is read-only.

Data Type

Integer

ExternalCryptoAsyncDocumentID Property (SecureBlackbox_MessageDecryptor Class)

Specifies an optional document ID for SignAsyncBegin() and SignAsyncEnd() calls.

Object Oriented Interface

public function getExternalCryptoAsyncDocumentID();
public function setExternalCryptoAsyncDocumentID($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 44 );
secureblackbox_messagedecryptor_set($res, 44, $value );

Default Value

''

Remarks

Specifies an optional document ID for SignAsyncBegin() and SignAsyncEnd() calls.

Use this property when working with multi-signature DCAuth requests and responses to uniquely identify documents signed within a larger batch. On the completion stage, this value helps the signing component identify the correct signature in the returned batch of responses.

If using batched requests, make sure to set this property to the same value on both the pre-signing (SignAsyncBegin) and completion (SignAsyncEnd) stages.

Data Type

String

ExternalCryptoCustomParams Property (SecureBlackbox_MessageDecryptor Class)

Custom parameters to be passed to the signing service (uninterpreted).

Object Oriented Interface

public function getExternalCryptoCustomParams();
public function setExternalCryptoCustomParams($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 45 );
secureblackbox_messagedecryptor_set($res, 45, $value );

Default Value

''

Remarks

Custom parameters to be passed to the signing service (uninterpreted).

This property is not available at design time.

Data Type

String

ExternalCryptoData Property (SecureBlackbox_MessageDecryptor Class)

Additional data to be included in the async state and mirrored back by the requestor.

Object Oriented Interface

public function getExternalCryptoData();
public function setExternalCryptoData($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 46 );
secureblackbox_messagedecryptor_set($res, 46, $value );

Default Value

''

Remarks

Additional data to be included in the async state and mirrored back by the requestor.

This property is not available at design time.

Data Type

String

ExternalCryptoExternalHashCalculation Property (SecureBlackbox_MessageDecryptor Class)

Specifies whether the message hash is to be calculated at the external endpoint.

Object Oriented Interface

public function getExternalCryptoExternalHashCalculation();
public function setExternalCryptoExternalHashCalculation($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 47 );
secureblackbox_messagedecryptor_set($res, 47, $value );

Default Value

false

Remarks

Specifies whether the message hash is to be calculated at the external endpoint. Please note that this mode is not supported by the DCAuth class.

If set to true, the class will pass a few kilobytes of to-be-signed data from the document to the OnExternalSign event. This only applies when SignExternal() is called.

Data Type

Boolean

ExternalCryptoHashAlgorithm Property (SecureBlackbox_MessageDecryptor Class)

Specifies the request's signature hash algorithm.

Object Oriented Interface

public function getExternalCryptoHashAlgorithm();
public function setExternalCryptoHashAlgorithm($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 48 );
secureblackbox_messagedecryptor_set($res, 48, $value );

Default Value

'SHA256'

Remarks

Specifies the request's signature hash algorithm.

Data Type

String

ExternalCryptoKeyID Property (SecureBlackbox_MessageDecryptor Class)

The ID of the pre-shared key used for DC request authentication.

Object Oriented Interface

public function getExternalCryptoKeyID();
public function setExternalCryptoKeyID($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 49 );
secureblackbox_messagedecryptor_set($res, 49, $value );

Default Value

''

Remarks

The ID of the pre-shared key used for DC request authentication.

Asynchronous DCAuth-driven communication requires that parties authenticate each other with a secret pre-shared cryptographic key. This provides an extra protection layer for the protocol and diminishes the risk of the private key becoming abused by foreign parties. Use this property to provide the pre-shared key identifier, and use ExternalCryptoKeySecret to pass the key itself.

The same KeyID/KeySecret pair should be used on the DCAuth side for the signing requests to be accepted.

Note: The KeyID/KeySecret scheme is very similar to the AuthKey scheme used in various Cloud service providers to authenticate users.

Example: signer.ExternalCrypto.KeyID = "MainSigningKey"; signer.ExternalCrypto.KeySecret = "abcdef0123456789";

Data Type

String

ExternalCryptoKeySecret Property (SecureBlackbox_MessageDecryptor Class)

The pre-shared key used for DC request authentication.

Object Oriented Interface

public function getExternalCryptoKeySecret();
public function setExternalCryptoKeySecret($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 50 );
secureblackbox_messagedecryptor_set($res, 50, $value );

Default Value

''

Remarks

The pre-shared key used for DC request authentication. This key must be set and match the key used by the DCAuth counterpart for the scheme to work.

Read more about configuring authentication in the ExternalCryptoKeyID topic.

Data Type

String

ExternalCryptoMethod Property (SecureBlackbox_MessageDecryptor Class)

Specifies the asynchronous signing method.

Object Oriented Interface

public function getExternalCryptoMethod();
public function setExternalCryptoMethod($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 51 );
secureblackbox_messagedecryptor_set($res, 51, $value );

Default Value

0

Remarks

Specifies the asynchronous signing method. This is typically defined by the DC server capabilities and setup.

Available options:

Data Type

Integer

ExternalCryptoMode Property (SecureBlackbox_MessageDecryptor Class)

Specifies the external cryptography mode.

Object Oriented Interface

public function getExternalCryptoMode();
public function setExternalCryptoMode($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 52 );
secureblackbox_messagedecryptor_set($res, 52, $value );

Default Value

0

Remarks

Specifies the external cryptography mode.

Available options:

This property is not available at design time.

Data Type

Integer

ExternalCryptoPublicKeyAlgorithm Property (SecureBlackbox_MessageDecryptor Class)

Provide the public key algorithm here if the certificate is not available on the pre-signing stage.

Object Oriented Interface

public function getExternalCryptoPublicKeyAlgorithm();
public function setExternalCryptoPublicKeyAlgorithm($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 53 );
secureblackbox_messagedecryptor_set($res, 53, $value );

Default Value

''

Remarks

Provide the public key algorithm here if the certificate is not available on the pre-signing stage.

Data Type

String

FIPSMode Property (SecureBlackbox_MessageDecryptor Class)

Reserved.

Object Oriented Interface

public function getFIPSMode();
public function setFIPSMode($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 54 );
secureblackbox_messagedecryptor_set($res, 54, $value );

Default Value

false

Remarks

This property is reserved for future use.

Data Type

Boolean

InputBytes Property (SecureBlackbox_MessageDecryptor Class)

Use this property to pass the input to class in byte array form.

Object Oriented Interface

public function getInputBytes();
public function setInputBytes($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 55 );
secureblackbox_messagedecryptor_set($res, 55, $value );

Remarks

Assign a byte array containing the data to be processed to this property.

This property is not available at design time.

Data Type

Byte Array

InputFile Property (SecureBlackbox_MessageDecryptor Class)

Path to the file containing the encrypted message.

Object Oriented Interface

public function getInputFile();
public function setInputFile($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 56 );
secureblackbox_messagedecryptor_set($res, 56, $value );

Default Value

''

Remarks

Use this property to provide a file containing the encrypted data.

Data Type

String

Key Property (SecureBlackbox_MessageDecryptor Class)

The symmetric key to use for decryption.

Object Oriented Interface

public function getKey();
public function setKey($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 57 );
secureblackbox_messagedecryptor_set($res, 57, $value );

Remarks

Use this property to provide the symmetric key to decrypt the data. This property is only applicable for processing data of EncryptedData subtype.

Assign this property before calling Decrypt.

This property is not available at design time.

Data Type

Byte Array

OutputBytes Property (SecureBlackbox_MessageDecryptor Class)

Use this property to read the output the class object has produced.

Object Oriented Interface

public function getOutputBytes();

Procedural Interface

secureblackbox_messagedecryptor_get($res, 58 );

Remarks

Read the contents of this property after the operation has completed to read the produced output. This property will only be set if the OutputFile and OutputStream properties had not been assigned.

This property is read-only and not available at design time.

Data Type

Byte Array

OutputFile Property (SecureBlackbox_MessageDecryptor Class)

Path to the file to save the decrypted data to.

Object Oriented Interface

public function getOutputFile();
public function setOutputFile($value);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 59 );
secureblackbox_messagedecryptor_set($res, 59, $value );

Default Value

''

Remarks

Use this property to specify the output file where the decrypted message should be saved.

Data Type

String

SignedAttributeCount Property (SecureBlackbox_MessageDecryptor Class)

The number of records in the SignedAttribute arrays.

Object Oriented Interface

public function getSignedAttributeCount();

Procedural Interface

secureblackbox_messagedecryptor_get($res, 60 );

Default Value

0

Remarks

This property controls the size of the following arrays:

• SignedAttributeOID
• SignedAttributeValue

The array indices start at 0 and end at SignedAttributeCount - 1.

This property is read-only and not available at design time.

Data Type

Integer

SignedAttributeOID Property (SecureBlackbox_MessageDecryptor Class)

The object identifier of the attribute.

Object Oriented Interface

public function getSignedAttributeOID($signedattributeindex);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 61 , $signedattributeindex);

Default Value

''

Remarks

The object identifier of the attribute.

The $signedattributeindex parameter specifies the index of the item in the array. The size of the array is controlled by the SignedAttributeCount property.

This property is read-only and not available at design time.

Data Type

String

SignedAttributeValue Property (SecureBlackbox_MessageDecryptor Class)

The value of the attribute.

Object Oriented Interface

public function getSignedAttributeValue($signedattributeindex);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 62 , $signedattributeindex);

Remarks

The value of the attribute.

The $signedattributeindex parameter specifies the index of the item in the array. The size of the array is controlled by the SignedAttributeCount property.

This property is read-only and not available at design time.

Data Type

Byte Array

UnsignedAttributeCount Property (SecureBlackbox_MessageDecryptor Class)

The number of records in the UnsignedAttribute arrays.

Object Oriented Interface

public function getUnsignedAttributeCount();

Procedural Interface

secureblackbox_messagedecryptor_get($res, 63 );

Default Value

0

Remarks

This property controls the size of the following arrays:

• UnsignedAttributeOID
• UnsignedAttributeValue

The array indices start at 0 and end at UnsignedAttributeCount - 1.

This property is read-only and not available at design time.

Data Type

Integer

UnsignedAttributeOID Property (SecureBlackbox_MessageDecryptor Class)

The object identifier of the attribute.

Object Oriented Interface

public function getUnsignedAttributeOID($unsignedattributeindex);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 64 , $unsignedattributeindex);

Default Value

''

Remarks

The object identifier of the attribute.

The $unsignedattributeindex parameter specifies the index of the item in the array. The size of the array is controlled by the UnsignedAttributeCount property.

This property is read-only and not available at design time.

Data Type

String

UnsignedAttributeValue Property (SecureBlackbox_MessageDecryptor Class)

The value of the attribute.

Object Oriented Interface

public function getUnsignedAttributeValue($unsignedattributeindex);

Procedural Interface

secureblackbox_messagedecryptor_get($res, 65 , $unsignedattributeindex);

Remarks

The value of the attribute.

The $unsignedattributeindex parameter specifies the index of the item in the array. The size of the array is controlled by the UnsignedAttributeCount property.

This property is read-only and not available at design time.

Data Type

Byte Array

CheckEncryptionType Method (SecureBlackbox_MessageDecryptor Class)

Determines the type of encrypted message in the supplied file.

Object Oriented Interface

public function doCheckEncryptionType();

Procedural Interface

secureblackbox_messagedecryptor_do_checkencryptiontype($res);

Remarks

Use this method to determine the kind of the signature stored in InputFile (InputStream).

Config Method (SecureBlackbox_MessageDecryptor Class)

Sets or retrieves a configuration setting.

Object Oriented Interface

public function doConfig($configurationstring);

Procedural Interface

secureblackbox_messagedecryptor_do_config($res, $configurationstring);

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Decrypt Method (SecureBlackbox_MessageDecryptor Class)

Attempts to decrypt an encrypted PKCS#7 message.

Object Oriented Interface

public function doDecrypt();

Procedural Interface

secureblackbox_messagedecryptor_do_decrypt($res);

Remarks

Call this method to attempt to decrypt the PKCS#7 encrypted data. This call supports EnvelopedData and EncryptedData subtypes on input.

Use InputFile or InputStream property to provide the data, and either Certificates or Key to supply the decryption key material.

When processing enveloped data, the class may fire RecipientFound event to report recipient information.

DoAction Method (SecureBlackbox_MessageDecryptor Class)

Performs an additional action.

Object Oriented Interface

public function doDoAction($actionid, $actionparams);

Procedural Interface

secureblackbox_messagedecryptor_do_doaction($res, $actionid, $actionparams);

Remarks

DoAction is a generic method available in every class. It is used to perform an additional action introduced after the product major release. The list of actions is not fixed, and may be flexibly extended over time.

The unique identifier (case insensitive) of the action is provided in the ActionID parameter.

ActionParams contains the value of a single parameter, or a list of multiple parameters for the action in the form of PARAM1=VALUE1;PARAM2=VALUE2;....

Common ActionIDs:

Reset Method (SecureBlackbox_MessageDecryptor Class)

Resets the class settings.

Object Oriented Interface

public function doReset();

Procedural Interface

secureblackbox_messagedecryptor_do_reset($res);

Remarks

Reset is a generic method available in every class.

Error Event (SecureBlackbox_MessageDecryptor Class)

Information about errors during PKCS#7 message decryption.

Object Oriented Interface

public function fireError($param);

Procedural Interface

secureblackbox_messagedecryptor_register_callback($res, 1, array($this, 'fireError'));

Parameter List

 'errorcode'
 'description'

Remarks

The event is fired in case of exceptional conditions during message processing.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Messages section.

ExternalDecrypt Event (SecureBlackbox_MessageDecryptor Class)

Handles remote or external decryption.

Object Oriented Interface

public function fireExternalDecrypt($param);

Procedural Interface

secureblackbox_messagedecryptor_register_callback($res, 2, array($this, 'fireExternalDecrypt'));

Parameter List

 'operationid'
 'algorithm'
 'pars'
 'encrypteddata'
 'data'

Remarks

Assign a handler to this event if you need to delegate a low-level decryption operation to an external, remote, or custom decryption engine. The handler receives an encrypted value in the EncryptedData parameter, and is expected to decrypt it and place the decrypted value into the Data parameter.

OperationId provides a comment about the operation and its origin. It depends on the exact class being used, and may be empty. Algorithm specifies the encryption algorithm being used, and Pars contains algorithm-dependent parameters.

The class uses base16 (hex) encoding for the EncryptedData, Data, and Pars parameters. If your decryption engine uses a different input and output encoding, you may need to decode and/or encode the data before and/or after the decryption.

Sample data encoded in base16: a0dee2a0382afbb09120ffa7ccd8a152 - lower case base16 A0DEE2A0382AFBB09120FFA7CCD8A152 - upper case base16

Notification Event (SecureBlackbox_MessageDecryptor Class)

This event notifies the application about an underlying control flow event.

Object Oriented Interface

public function fireNotification($param);

Procedural Interface

secureblackbox_messagedecryptor_register_callback($res, 3, array($this, 'fireNotification'));

Parameter List

 'eventid'
 'eventparam'

Remarks

The class fires this event to let the application know about some event, occurrence, or milestone in the class. For example, it may fire to report completion of the document processing. The list of events being reported is not fixed, and may be flexibly extended over time.

The unique identifier of the event is provided in the EventID parameter. EventParam contains any parameters accompanying the occurrence. Depending on the type of the class, the exact action it is performing, or the document being processed, one or both may be omitted.

RecipientFound Event (SecureBlackbox_MessageDecryptor Class)

Fires to report a message addressee parameters.

Object Oriented Interface

public function fireRecipientFound($param);

Procedural Interface

secureblackbox_messagedecryptor_register_callback($res, 4, array($this, 'fireRecipientFound'));

Parameter List

 'issuerrdn'
 'serialnumber'
 'subjectkeyid'
 'certfound'

Remarks

This event is fired for each addressee the message is encrypted for. It may fire several times in a row if the message is encrypted for more than one recipient.

The IssuerRDN, SerialNumber, and SubjectKeyID parameters to identify the recipient's certificate. CertFound indicates if the specified certificate has been located in Certificates collection. If it wasn't, you might want to look up the certificate manually, and add it to the collection inside the event handler.

Config Settings (MessageDecryptor Class)

The class accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

MessageDecryptor Config Settings

Base Config Settings

Trappable Errors (MessageDecryptor Class)

MessageDecryptor Errors