this class provides the main interface to the dcmsign module - it allows to create, examine and verify digital signatures in DICOM datasets or items. More...

Public Member Functions
	DcmSignature ()
	default constructor

virtual	~DcmSignature ()
	destructor

void	attach (DcmItem *dataset)
	attaches a DICOM dataset or item to the signature object. More...

void	detach ()
	detaches an attached DICOM dataset from the signature object.

OFCondition	createSignature (SiPrivateKey &key, SiCertificate &cert, SiMAC &mac, SiSecurityProfile &profile, E_TransferSyntax xfer=EXS_LittleEndianExplicit, const DcmAttributeTag tagList=NULL, SiTimeStamp timeStamp=NULL, SiSignaturePurpose::E_SignaturePurposeType sigPurpose=SiSignaturePurpose::ESP_none)
	creates a new digital signature in the current dataset. More...

unsigned long	numberOfSignatures ()
	returns the number of signatures in the dataset. More...

OFCondition	removeSignature (unsigned long i)
	removes a signature from the dataset. More...

OFCondition	selectSignature (unsigned long i)
	selects one of the digital signatures from the attached dataset for reading. More...

OFCondition	verifyCurrent ()
	verifies the current signature. More...

OFCondition	getCurrentMacID (Uint16 &macID)
	returns the MAC ID of the current signature. More...

OFCondition	getCurrentMacXferSyntaxName (OFString &str)
	returns the MAC Calculation Transfer Syntax of the current signature. More...

OFCondition	getCurrentMacName (OFString &str)
	returns the MAC Algorithm Name of the current signature. More...

OFCondition	getCurrentSignatureUID (OFString &str)
	returns the Digital Signature UID of the current signature. More...

OFCondition	getCurrentSignatureDateTime (OFString &str)
	returns the Signature Date/Time of the current signature. More...

DcmDateTime *	getCurrentSignatureDateTime ()
	returns a pointer to the object representing Signature Date/Time of the current signature. More...

OFCondition	getCurrentDataElementsSigned (DcmAttributeTag &desig)
	returns the Data Elements Signed attribute of the current signature if present. More...

OFCondition	getCurrentSignaturePurpose (OFString &codeValue, OFString &codeMeaning, OFString &codingSchemeDesignator)
	returns the signature purpose code of the current signature if present. More...

OFCondition	verifySignatureProfile (SiSecurityProfile &sprof)
	verifies whether the currently selected signature within the currently attached dataset matches the requirements of the given signature profile. More...

SiCertificate *	getCurrentCertificate ()
	returns the certificate of the current signature if present. More...

SiTimeStamp *	getCurrentTimestamp ()
	returns the certified timestamp of the current signature if present. More...

DcmItem *	getSelectedSignatureItem ()
	returns the item of the DigitalSignaturesSequence selected by the last call to selectSignature(), or NULL if no signature has been selected. More...

void	setDumpFile (FILE *f)
	dump all data that is fed into the MAC algorithm into the given file, which must be opened and closed by caller. More...

Static Public Member Functions
static void	initializeLibrary ()
	initializes the dcmsign library including the underlying OpenSSL library. More...

static DcmItem *	findFirstSignatureItem (DcmItem &item, DcmStack &stack)
	recursively browses through the given dataset and searches the first occurrence of the DigitalSignaturesSequence. More...

static DcmItem *	findNextSignatureItem (DcmItem &item, DcmStack &stack)
	recursively browses through the given dataset and searches the next occurrence of the DigitalSignaturesSequence. More...

static void	adjustASN1SequenceLength (const unsigned char *buf, unsigned long &buflen)
	check a DER encoded ASN.1 SEQUENCE structure for a possible pad byte and, if a pad byte is detected, remove it by decreasing buflen. More...

Private Member Functions
	DcmSignature (DcmSignature &arg)
	private undefined copy constructor

DcmSignature &	operator= (DcmSignature &arg)
	private undefined copy assignment operator

void	deselect ()
	removes the selection of a current signature if present

OFCondition	allocateMACID (Uint16 &newID)
	allocates a new mac ID number for a new signature. More...

Static Private Member Functions
static OFCondition	getMACIDnumber (DcmItem &item, Uint16 &macid)
	searches a given item for the DCM_MACIDnumber element and returns its value if present More...

static OFCondition	checkListOfSignedTags (const DcmAttributeTag tagList, const DcmAttributeTag tagListOut)
	checks if all tags from tagList are present in tagListOut, which is the list of attribute tags actually included in a signature, including tags added due to a signature profile, and without tags that were absent in the dataset. More...

static OFBool	inTagList (const DcmTagKey &tag, const DcmAttributeTag &tagList)
	checks if the given tag key is present in tagList More...

static void	currentDateTime (OFString &str)
	returns the current date and time as a DICOM DT string. More...

Private Attributes
DcmItem *	currentItem
	pointer to current item if attached, NULL otherwise

DcmSequenceOfItems *	macParametersSq
	pointer to mac parameters sequence of attached item, may be NULL if not attached or not yet present

DcmSequenceOfItems *	signatureSq
	pointer to digital signatures sequence of attached item, may be NULL if not attached or not yet present

FILE *	dumpFile
	if nonzero, the data fed to the MAC algorithm is also stored in this file.

DcmItem *	selectedSignatureItem
	pointer to currently selected signature item

DcmItem *	selectedMacParametersItem
	pointer to currently selected mac parameters item

SiCertificate *	selectedCertificate
	pointer to certificate for currently selected signature item

SiTimeStamp *	selectedTimestamp
	pointer to certified timestamp for currently selected signature item

Detailed Description

this class provides the main interface to the dcmsign module - it allows to create, examine and verify digital signatures in DICOM datasets or items.

The methods in this class do not handle digital signatures embedded in sequence items within the dataset, other than providing helper functions that allow to locate and attach the sub-items separately.

Remarks: this class is only available if DCMTK is compiled with OpenSSL support enabled.

Member Function Documentation

◆ adjustASN1SequenceLength()

static void DcmSignature::adjustASN1SequenceLength	(	const unsigned char *	buf,
		unsigned long &	buflen
	)

static

check a DER encoded ASN.1 SEQUENCE structure for a possible pad byte and, if a pad byte is detected, remove it by decreasing buflen.

This will work for SEQUENCEs with one byte and two byte encoding (i.e. max 64 kBytes).

Parameters

buf	pointer to DER encoded ASN.1 data
buflen	length of buffer pointed to, in bytes. The variable is decreased by one if a pad byte is detected.

◆ allocateMACID()

OFCondition DcmSignature::allocateMACID ( Uint16 & newID )

private

allocates a new mac ID number for a new signature.

examines all mac ID numbers in the digital signatures sequence and in the mac parameters sequence and returns an unused number.

Parameters

newID upon successful return, new number is passed in this parameter

Returns: status code

◆ attach()

void DcmSignature::attach ( DcmItem * dataset )

attaches a DICOM dataset or item to the signature object.

The dataset is detached by a call to detach() or by destruction of the signature object. This object may modify but never deletes an attached dataset.

Parameters

dataset dataset or item to be attached

◆ checkListOfSignedTags()

static OFCondition DcmSignature::checkListOfSignedTags	(	const DcmAttributeTag *	tagList,
		const DcmAttributeTag *	tagListOut
	)

staticprivate

checks if all tags from tagList are present in tagListOut, which is the list of attribute tags actually included in a signature, including tags added due to a signature profile, and without tags that were absent in the dataset.

Parameters

tagList	list of attribute tags that should be present in the signature, may be NULL
tagListOut	list of attribute tags actually present in the signature, must not be NULL

Returns: EC_Normal if check succeeds, an error code otherwise

◆ createSignature()

OFCondition DcmSignature::createSignature	(	SiPrivateKey &	key,
		SiCertificate &	cert,
		SiMAC &	mac,
		SiSecurityProfile &	profile,
		E_TransferSyntax	xfer = `EXS_LittleEndianExplicit`,
		const DcmAttributeTag *	tagList = `NULL`,
		SiTimeStamp *	timeStamp = `NULL`,
		SiSignaturePurpose::E_SignaturePurposeType	sigPurpose = `SiSignaturePurpose::ESP_none`
	)

creates a new digital signature in the current dataset.

Checks whether private and public key match and whether all requirements of the given security profile are fulfilled.

Parameters

key	private key for signature creation
cert	certificate with public key
mac	MAC algorithm to be used for signature creation
profile	security profile for signature creation
xfer	transfer syntax to use when serializing DICOM data
tagList	pointer to list of attribute tags to sign, may be NULL. If this parameter is nonzero, it contains a list of attribute sign. The real list of attributes signed is derived from this parameter plus the requirements of the security profile. If NULL, a universal match is assumed, i.e. all signable attributes in the data set are signed.
timeStamp	pointer to time stamp client used to create timestamps for the digital signature.
sigPurpose	digital signature purpose

Returns: status code

◆ currentDateTime()

static void DcmSignature::currentDateTime ( OFString & str )

staticprivate

returns the current date and time as a DICOM DT string.

Parameters

str	date/time returned in this string.

◆ findFirstSignatureItem()

static DcmItem* DcmSignature::findFirstSignatureItem	(	DcmItem &	item,
		DcmStack &	stack
	)

static

recursively browses through the given dataset and searches the first occurrence of the DigitalSignaturesSequence.

If found, returns a pointer to the Item in which the sequence is contained.

Parameters

item	dataset to be browsed
stack	search stack, must be passed to findNextSignatureItem() later on.

Returns: pointer to Item containing a DigitalSignatureSequence if found, NULL otherwise.

◆ findNextSignatureItem()

static DcmItem* DcmSignature::findNextSignatureItem	(	DcmItem &	item,
		DcmStack &	stack
	)

static

recursively browses through the given dataset and searches the next occurrence of the DigitalSignaturesSequence.

If found, returns a pointer to the Item in which the sequence is contained.

Parameters

item	dataset to be browsed
stack	search stack as returned by findFirstSignatureItem() or the last call to this method.

Returns: pointer to Item containing a DigitalSignatureSequence if found, NULL otherwise.

◆ getCurrentCertificate()

SiCertificate* DcmSignature::getCurrentCertificate ( )

returns the certificate of the current signature if present.

Current signature must be selected with selectSignature(). May return NULL if certificate is unavailable.

Returns: pointer to current certificate, NULL if unavailable.

◆ getCurrentDataElementsSigned()

OFCondition DcmSignature::getCurrentDataElementsSigned ( DcmAttributeTag & desig )

returns the Data Elements Signed attribute of the current signature if present.

Current signature must be selected with selectSignature(). If a valid signature is selected but the signature does not contain the Data Elements Signed element (i.e. all attributes are signed), this method returns an error code.

Parameters

desig data elements signed returned in this parameter upon success

Returns: status code

◆ getCurrentMacID()

OFCondition DcmSignature::getCurrentMacID ( Uint16 & macID )

returns the MAC ID of the current signature.

Current signature must be selected with selectSignature().

Parameters

macID MAC ID returned in this parameter upon success

Returns: status code

◆ getCurrentMacName()

OFCondition DcmSignature::getCurrentMacName ( OFString & str )

returns the MAC Algorithm Name of the current signature.

Current signature must be selected with selectSignature().

Parameters

str	MAC algorithm name returned in this parameter upon success

Returns: status code

◆ getCurrentMacXferSyntaxName()

OFCondition DcmSignature::getCurrentMacXferSyntaxName ( OFString & str )

returns the MAC Calculation Transfer Syntax of the current signature.

If the transfer syntax is well-known, the UID is replaced by the transfer syntax name preceded by '='. Current signature must be selected with selectSignature().

Parameters

str	transfer syntax name or UID returned in this parameter upon success

Returns: status code

◆ getCurrentSignatureDateTime() [1/2]

DcmDateTime* DcmSignature::getCurrentSignatureDateTime ( )

returns a pointer to the object representing Signature Date/Time of the current signature.

Current signature must be selected with selectSignature().

Returns: pointer to signature datetime if present, NULL otherwise

◆ getCurrentSignatureDateTime() [2/2]

OFCondition DcmSignature::getCurrentSignatureDateTime ( OFString & str )

returns the Signature Date/Time of the current signature.

Current signature must be selected with selectSignature().

Parameters

str	signature date/time returned in this parameter upon success

Returns: status code

◆ getCurrentSignaturePurpose()

OFCondition DcmSignature::getCurrentSignaturePurpose	(	OFString &	codeValue,
		OFString &	codeMeaning,
		OFString &	codingSchemeDesignator
	)

returns the signature purpose code of the current signature if present.

Current signature must be selected with selectSignature(). If a valid signature is selected but the signature does not contain a valid SignaturePurposeCodeSequence, this method returns an error code.

Parameters

codeValue	signature purpose code value returned in this parameter upon success
codeMeaning	signature purpose code meaning returned in this parameter upon success
codingSchemeDesignator	signature purpose coding scheme designator returned in this parameter upon success

Returns: status code

◆ getCurrentSignatureUID()

OFCondition DcmSignature::getCurrentSignatureUID ( OFString & str )

returns the Digital Signature UID of the current signature.

Current signature must be selected with selectSignature().

Parameters

str	signature UID returned in this parameter upon success

Returns: status code

◆ getCurrentTimestamp()

SiTimeStamp* DcmSignature::getCurrentTimestamp ( )

returns the certified timestamp of the current signature if present.

Current signature must be selected with selectSignature(). May return NULL if timestamp is unavailable.

Returns: pointer to current timestamp, NULL if unavailable.

◆ getMACIDnumber()

static OFCondition DcmSignature::getMACIDnumber	(	DcmItem &	item,
		Uint16 &	macid
	)

staticprivate

searches a given item for the DCM_MACIDnumber element and returns its value if present

Parameters

item	item to be searched
macid	MAC ID returned in this parameter upon success

Returns: EC_Normal if successful, an error code otherwise

◆ getSelectedSignatureItem()

DcmItem* DcmSignature::getSelectedSignatureItem ( )

returns the item of the DigitalSignaturesSequence selected by the last call to selectSignature(), or NULL if no signature has been selected.

Returns: pointer to current signature item, may be NULL

◆ initializeLibrary()

static void DcmSignature::initializeLibrary ( )

static

initializes the dcmsign library including the underlying OpenSSL library.

this method should be called by main() before any object of the dcmsign library is created or used.

◆ inTagList()

static OFBool DcmSignature::inTagList	(	const DcmTagKey &	tag,
		const DcmAttributeTag &	tagList
	)

staticprivate

checks if the given tag key is present in tagList

Parameters

tag	tag key
tagList	list of tag keys

Returns: OFTrue of tag is present in tagList, OFFalse otherwise

◆ numberOfSignatures()

unsigned long DcmSignature::numberOfSignatures ( )

returns the number of signatures in the dataset.

Does not count signatures embedded in sequence items within the dataset.

◆ removeSignature()

OFCondition DcmSignature::removeSignature ( unsigned long i )

removes a signature from the dataset.

Parameters

i	index, must be < numberOfSignatures().

Returns: status code

◆ selectSignature()

OFCondition DcmSignature::selectSignature ( unsigned long i )

selects one of the digital signatures from the attached dataset for reading.

Parameters

i	index, must be < numberOfSignatures()

Returns: status code

◆ setDumpFile()

void DcmSignature::setDumpFile ( FILE * f )

dump all data that is fed into the MAC algorithm into the given file, which must be opened and closed by caller.

Parameters

f	pointer to file already opened for writing; may be NULL.

◆ verifyCurrent()

OFCondition DcmSignature::verifyCurrent ( )

verifies the current signature.

Current signature must be selected with selectSignature().

Returns: SI_EC_Normal if signature is complete and valid, an error code describing the type of verification failure otherwise.

◆ verifySignatureProfile()

OFCondition DcmSignature::verifySignatureProfile ( SiSecurityProfile & sprof )

verifies whether the currently selected signature within the currently attached dataset matches the requirements of the given signature profile.

Parameters

sprof security profile

Returns: EC_Normal if signature matches, an error code otherwise

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

dcmsign/include/dcmtk/dcmsign/dcsignat.h

Public Member Functions

Static Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Detailed Description

Member Function Documentation

◆ adjustASN1SequenceLength()

◆ allocateMACID()

◆ attach()

◆ checkListOfSignedTags()

◆ createSignature()

◆ currentDateTime()

◆ findFirstSignatureItem()

◆ findNextSignatureItem()

◆ getCurrentCertificate()

◆ getCurrentDataElementsSigned()

◆ getCurrentMacID()

◆ getCurrentMacName()

◆ getCurrentMacXferSyntaxName()

◆ getCurrentSignatureDateTime() [1/2]

◆ getCurrentSignatureDateTime() [2/2]

◆ getCurrentSignaturePurpose()

◆ getCurrentSignatureUID()

◆ getCurrentTimestamp()

◆ getMACIDnumber()

◆ getSelectedSignatureItem()

◆ initializeLibrary()

◆ inTagList()

◆ numberOfSignatures()

◆ removeSignature()

◆ selectSignature()

◆ setDumpFile()

◆ verifyCurrent()

◆ verifySignatureProfile()