PDFVerifier Component

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The PDFVerifier component verifies signatures over PDF documents.

Syntax

TsbxPDFVerifier

Remarks

Use PDFVerifier to validate electronic signatures over PDF documents. Generic and PAdES signatures are supported. PDFVerifier verifier = new PDFVerifier(); // Set the signed PDF document that you want to verify verifier.setInputFile("signed.pdf"); verifier.verify(); // Verification information for (int idx = 0; idx < verifier.getSignatures().size(); idx++) { System.out.println("Signature " + (idx + 1)); System.out.println(" Timestamp: " + verifier.getSignatures().item(idx).getValidatedSigningTime()); System.out.print(" Validation Result: " + verifier.getSignatures().item(idx).getSignatureValidationResult() + ", "); switch (verifier.getSignatures().item(idx).getSignatureValidationResult()) { case svtValid: System.out.println("The signature is valid."); break; case svtUnknown: System.out.println("Signature validity is unknown."); break; case svtCorrupted: System.out.println("The signature is corrupted."); break; case svtSignerNotFound: System.out.println("Failed to acquire the signing certificate. The signature cannot be validated."); break; case svtFailure: System.out.println("General failure."); break; default: System.out.println("Signature validity is unknown."); break; } }

PDFVerifier validates each signature from two perspectives: the integrity and validity of the signature itself (i.e. its correspondence to the document data it covers), and the validity and trustworthiness of the signing certificate chain. These two signature aspects are generally independent of each other: the signature may be valid but the chain may not be trusted, or the other way around, the chain may be trusted but the integrity of the signature may be violated. Under normal circumstances both the signature and the chain must be valid for the signature to be considered good.

To initiate the validation, assign the path to the signed PDF file to the InputFile property (alternatively, you can provide it in a memory buffer via the InputBytes property), and call the Verify method. For every signature located in the document, PDFVerifier will fire the SignatureFound event. This event lets you specify whether you want PDFVerifier to validate the signature, the chain, or both.

Note: it does not mean that any of the two is optional. This API lets you be flexible in how you validate documents in your code in accordance with the specifics of your application and its usage scenarios. For example, if your trust environment relies on certificate pinning, validating the chain by PDFVerifier internally may cause unnecessary burden on the system, in which case it may be reasonable to disable it in the event handler.

Once SignatureFound returns, PDFVerifier proceeds to the signature validation routine in accordance with the provided settings. Upon completion of the validation, the SignatureValidated event is fired, and the validation results are separately provided via the SignatureValidationResult and ChainValidationResult fields of the associated signature object. Other information about the signature can be accessed via the Signatures property.

The PDF format uses incremental updates to introduce changes to the document. This implies that a signature may cover not the whole document, but rather a certain revision of it. Strictly speaking, every signature in a PDF document, apart from perhaps the last one, covers just some part of the document. In most cases that part matches the revision of the document that existed before all the subsequent signatures had been added.

Because of these specifics of the PDF format, it is crucially important to understand which part of the document is covered by a specific signature. Use the CoverageEndsAt field to establish the scope of a signature. The revision of the document covered by that specific signature ranges from byte 0 to CoverageEndsAt. Alternatively, you can use the GetSignedVersion method to extract the signed revision to a file.

Useful settings and properties

The following properties of PDFVerifier may be handy when working with this component:

• OfflineMode lets you validate the document without contacting online revocation sources. Paired with switched-off system trust settings, it can be used to establish the long-term validity of the document and the completeness of the validation material included in it.
• RevocationCheck lets you adjust the revocation checking preferences.
• ValidatedSigningTime returns the signing time as recorded in the embedded signature timestamp. This is in contrast to ClaimedSigningTime, which returns the signing time as specified by the signer.
• ValidationLog is a great way to find out the details of chain validation failures. This property returns a comprehensive validation log that reports all the issues encountered during the validation.
• If the document is encrypted (in addition to being signed), the Encrypted event will fire, asking you for the decryption certificate or password.

By default, PDFVerifier uses the system trust settings to establish certificate chain validity. You can configure it to use your own, custom validation environment by providing the necessary trust elements via KnownCertificates, TrustedCertificates, KnownCRLs, and other similar properties.

Property List

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

AllSignaturesValid Property (PDFVerifier Component)

The cumulative validity of all signatures.

Syntax

property AllSignaturesValid: Boolean read get_AllSignaturesValid;

Default Value

false

Remarks

Use this property to check if all the signatures found in the message or document are valid.

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

AttachedFiles Property (PDFVerifier Component)

Provides details of all attached files found in the PDF document.

Syntax

property AttachedFiles: TsbxMailAttachmentList read get_AttachedFiles;

Remarks

Use this property to get the details of all the attached files identified in the document.

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

Please refer to the MailAttachment type for a complete list of fields.

AutoValidateSignatures Property (PDFVerifier Component)

Specifies whether PDFVerifier should validate any present signatures when the document is opened.

Syntax

property AutoValidateSignatures: Boolean read get_AutoValidateSignatures write set_AutoValidateSignatures;

Default Value

true

Remarks

This setting is switched on by default. You can choose to set this property to false in order to validate the signatures manually on a later stage using the Revalidate method.

BlockedCertificates Property (PDFVerifier Component)

The certificates that must be rejected as trust anchors.

Syntax

property BlockedCertificates: TsbxCertificateList read get_BlockedCertificates write set_BlockedCertificates;

Remarks

Use this property to provide a list of compromised or blocked certificates. Any chain containing a blocked certificate will fail validation.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

Certificates Property (PDFVerifier Component)

A collection of certificates included in the electronic signature.

Syntax

property Certificates: TsbxCertificateList read get_Certificates;

Remarks

This property includes a collection of certificates of the currently selected info.

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

Please refer to the Certificate type for a complete list of fields.

CheckTrustedLists Property (PDFVerifier Component)

Specifies whether the component should attempt to validate chain trust via a known Trusted List.

Syntax

property CheckTrustedLists: Boolean read get_CheckTrustedLists write set_CheckTrustedLists;

Default Value

false

Remarks

Set this property to true to enable the component to validate chain trust against an internal list of known Trusted Lists (such as EUTL).

CRLs Property (PDFVerifier Component)

A collection of certificate revocation lists embedded into the signature by the signer.

Syntax

property CRLs: TsbxCRLList read get_CRLs;

Remarks

Use this property to access the CRLs embedded into the signature by the signer.

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

Please refer to the CRL type for a complete list of fields.

DecryptionCertificate Property (PDFVerifier Component)

A decryption certificate.

Syntax

property DecryptionCertificate: TsbxCertificate read get_DecryptionCertificate write set_DecryptionCertificate;

Remarks

Use this property to provide the decryption certificate. The certificate should have a private key associated with it.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

DocumentInfo Property (PDFVerifier Component)

Contains information about the document properties.

Syntax

property DocumentInfo: TsbxPDFDocumentInfo read get_DocumentInfo;

Remarks

Use this property to access general parameters of the document being processed. A good place to check this property is in the handler of the DocumentLoaded event.

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

Please refer to the PDFDocumentInfo type for a complete list of fields.

FIPSMode Property (PDFVerifier Component)

Reserved.

Syntax

property FIPSMode: Boolean read get_FIPSMode write set_FIPSMode;

Default Value

false

Remarks

This property is reserved for future use.

IgnoreChainValidationErrors Property (PDFVerifier Component)

Makes the component tolerant to chain validation errors.

Syntax

property IgnoreChainValidationErrors: Boolean read get_IgnoreChainValidationErrors write set_IgnoreChainValidationErrors;

Default Value

false

Remarks

If this property is set to True, any errors emerging during certificate chain validation will be ignored. This setting may be handy if the purpose of validation is the creation of an LTV signature, and the validation is performed in an environment that doesn't trust the signer's certificate chain.

InputBytes Property (PDFVerifier Component)

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

Syntax

property InputBytes: TBytes read get_InputBytes write set_InputBytes;

Remarks

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

This property is not available at design time.

InputFile Property (PDFVerifier Component)

A path to the signed PDF file.

Syntax

property InputFile: String read get_InputFile write set_InputFile;

Default Value

''

Remarks

Assign the path to the PDF file to be verified to this property.

KnownCertificates Property (PDFVerifier Component)

Additional certificates for chain validation.

Syntax

property KnownCertificates: TsbxCertificateList read get_KnownCertificates write set_KnownCertificates;

Remarks

Use this property to supply a list of additional certificates that might be needed for chain validation. An example of a scenario where you might want to do that is when intermediary CA certificates are absent from the standard system locations (or when there are no standard system locations), and therefore should be supplied to the component manually.

The purpose of the certificates to be added to this collection is roughly equivalent to that of the Intermediate Certification Authorities system store in Windows.

Do not add trust anchors or root certificates to this collection: add them to TrustedCertificates instead.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

KnownCRLs Property (PDFVerifier Component)

Additional CRLs for chain validation.

Syntax

property KnownCRLs: TsbxCRLList read get_KnownCRLs write set_KnownCRLs;

Remarks

Use this property to supply additional CRLs that might be needed for chain validation. This property may be helpful when a chain is validated in offline mode, and the associated CRLs are stored separately from the signed message or document.

This property is not available at design time.

Please refer to the CRL type for a complete list of fields.

KnownOCSPs Property (PDFVerifier Component)

Additional OCSP responses for chain validation.

Syntax

property KnownOCSPs: TsbxOCSPResponseList read get_KnownOCSPs write set_KnownOCSPs;

Remarks

Use this property to supply additional OCSP responses that might be needed for chain validation. This property may be helpful when a chain is validated in offline mode, and the associated OCSP responses are stored separately from the signed message or document.

This property is not available at design time.

Please refer to the OCSPResponse type for a complete list of fields.

OCSPs Property (PDFVerifier Component)

A collection of OCSP responses embedded into the signature.

Syntax

property OCSPs: TsbxOCSPResponseList read get_OCSPs;

Remarks

Use this property to access the OCSP responses embedded into the signature by its creator.

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

Please refer to the OCSPResponse type for a complete list of fields.

OfflineMode Property (PDFVerifier Component)

Switches the component to offline mode.

Syntax

property OfflineMode: Boolean read get_OfflineMode write set_OfflineMode;

Default Value

false

Remarks

When working in offline mode, the component restricts itself from using any online revocation information sources, such as CRL or OCSP responders.

Offline mode may be useful if there is a need to verify the completeness of the validation information included within the signature or provided via KnownCertificates, KnownCRLs, and other related properties.

OutputBytes Property (PDFVerifier Component)

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

Syntax

property OutputBytes: TBytes read get_OutputBytes;

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.

OutputFile Property (PDFVerifier Component)

The file to save the signed or updated document to.

Syntax

property OutputFile: String read get_OutputFile write set_OutputFile;

Default Value

''

Remarks

Use this property to provide a path where the resulting PDF document should be saved to.

Pages Property (PDFVerifier Component)

A list of pages contained in the document.

Syntax

property Pages: TsbxPDFPageList read get_Pages;

Remarks

Use this property to read document page information. This property is initialized when the DocumentLoaded event fires.

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

Please refer to the PDFPage type for a complete list of fields.

Password Property (PDFVerifier Component)

The decryption password.

Syntax

property Password: String read get_Password write set_Password;

Default Value

''

Remarks

Use this property to provide the decryption password.

Profile Property (PDFVerifier Component)

Specifies a pre-defined profile to apply when creating the signature.

Syntax

property Profile: String read get_Profile write set_Profile;

Default Value

''

Remarks

Advanced signatures come in many variants, which are often defined by parties that needs to process them or by local standards. SecureBlackbox profiles are sets of pre-defined configurations which correspond to particular signature variants. By specifying a profile, you are pre-configuring the component to make it produce the signature that matches the configuration corresponding to that profile.

Proxy Property (PDFVerifier Component)

The proxy server settings.

Syntax

property Proxy: TsbxProxySettings read get_Proxy;

Remarks

Use this property to tune up the proxy server settings.

This property is read-only.

Please refer to the ProxySettings type for a complete list of fields.

RevocationCheck Property (PDFVerifier Component)

Specifies the kind(s) of revocation check to perform for all chain certificates.

Syntax

property RevocationCheck: TsbxRevocationCheckKinds read get_RevocationCheck write set_RevocationCheck;

TsbxRevocationCheckKinds = (
  crcNone,
  crcAuto,
  crcAllCRL,
  crcAllOCSP,
  crcAllCRLAndOCSP,
  crcAnyCRL,
  crcAnyOCSP,
  crcAnyCRLOrOCSP,
  crcAnyOCSPOrCRL
);

Default Value

crcAuto

Remarks

Revocation checking is necessary to ensure the integrity of the chain and obtain up-to-date certificate validity and trustworthiness information.

Certificate Revocation Lists (CRLs) and Online Certificate Status Protocol (OCSP) responses serve the same purpose of ensuring that the certificate had not been revoked by the Certificate Authority (CA) at the time of use. Depending on your circumstances and security policy requirements, you may want to use either one or both of the revocation information source types.

This setting controls the way the revocation checks are performed for every certificate in the chain. Typically certificates come with two types of revocation information sources: CRL (certificate revocation lists) and OCSP responders. CRLs are static objects periodically published by the CA at some online location. OCSP responders are active online services maintained by the CA that can provide up-to-date information on certificate statuses in near real time.

There are some conceptual differences between the two. CRLs are normally larger in size. Their use involves some latency because there is normally some delay between the time when a certificate was revoked and the time the subsequent CRL mentioning that is published. The benefits of CRL is that the same object can provide statuses for all certificates issued by a particular CA, and that the whole technology is much simpler than OCSP (and thus is supported by more CAs).

This setting lets you adjust the validation course by including or excluding certain types of revocation sources from the validation process. The crcAnyOCSPOrCRL setting (give preference to the faster OCSP route and only demand one source to succeed) is a good choice for most typical validation environments. The 'crcAll*' modes are much stricter, and may be used in scenarios where bulletproof validity information is essential.

Note: If no CRL or OCSP endpoints are provided by the CA, the revocation check will be considered successful. This is because the CA chose not to supply revocation information for its certificates, meaning they are considered irrevocable.

Note: Within each of the above settings, if any retrieved CRL or OCSP response indicates that the certificate has been revoked, the revocation check fails.

Signatures Property (PDFVerifier Component)

Provides details of all signatures found in the PDF document.

Syntax

property Signatures: TsbxPDFSignatureList read get_Signatures;

Remarks

Upon completion of the validation process conducted by the Verify method, all the signature details are populated in this property.

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

Please refer to the PDFSignature type for a complete list of fields.

SocketSettings Property (PDFVerifier Component)

Manages network connection settings.

Syntax

property SocketSettings: TsbxSocketSettings read get_SocketSettings;

Remarks

Use this property to tune up network connection parameters.

This property is read-only.

Please refer to the SocketSettings type for a complete list of fields.

Timestamps Property (PDFVerifier Component)

Contains a collection of timestamps for the processed document.

Syntax

property Timestamps: TsbxTimestampInfoList read get_Timestamps;

Remarks

Use this property to access the timestamps included in the processed document.

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

Please refer to the TimestampInfo type for a complete list of fields.

TLSClientChain Property (PDFVerifier Component)

The TLS client certificate chain.

Syntax

property TLSClientChain: TsbxCertificateList read get_TLSClientChain write set_TLSClientChain;

Remarks

Assign a certificate chain to this property to enable TLS client authentication in the component. Note that the client's end-entity certificate should have a private key associated with it.

Use the CertificateStorage or CertificateManager components to import the certificate from a file, system store, or PKCS11 device.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

TLSServerChain Property (PDFVerifier Component)

The TLS server's certificate chain.

Syntax

property TLSServerChain: TsbxCertificateList read get_TLSServerChain;

Remarks

Use this property to access the certificate chain sent by the TLS server. This property is ready to read when the TLSCertValidate event is fired by the client component.

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

Please refer to the Certificate type for a complete list of fields.

TLSSettings Property (PDFVerifier Component)

Manages TLS layer settings.

Syntax

property TLSSettings: TsbxTLSSettings read get_TLSSettings;

Remarks

Use this property to tune up the TLS layer parameters.

This property is read-only.

Please refer to the TLSSettings type for a complete list of fields.

TrustedCertificates Property (PDFVerifier Component)

A list of trusted certificates for chain validation.

Syntax

property TrustedCertificates: TsbxCertificateList read get_TrustedCertificates write set_TrustedCertificates;

Remarks

Use this property to supply a list of trusted certificates that might be needed for chain validation. An example of a scenario where you might want to do that is when root CA certificates are absent from the standard system locations (or when there are no standard system locations), and therefore should be supplied to the component manually.

The purpose of this certificate collection is largely the same as that of the Windows Trusted Root Certification Authorities system store.

Use this property with extreme care as it directly affects chain verifiability; a wrong certificate added to the trusted list may result in bad chains being accepted, and forfeited signatures being recognized as genuine. Only add certificates that originate from the parties that you know and trust.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

ValidationMoment Property (PDFVerifier Component)

The time point at which signature validity is to be established.

Syntax

property ValidationMoment: String read get_ValidationMoment write set_ValidationMoment;

Default Value

''

Remarks

Use this property to specify the moment in time at which signature validity should be established. The time is in UTC. Leave the setting empty to stick to the default moment (either the signature creation time or the current time).

The validity of the same signature may differ depending on the time point chosen due to temporal changes in chain validities, revocation statuses, and timestamp times.

Close Method (PDFVerifier Component)

Closes an opened document.

Syntax

procedure Close(SaveChanges: Boolean);

Remarks

Use this method to close a previously opened document. The SaveChanges parameter is only taken into account if the document was opened in edit mode.

Config Method (PDFVerifier Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): String;

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, 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.

DoAction Method (PDFVerifier Component)

Performs an additional action.

Syntax

function DoAction(ActionID: String; ActionParams: String): String;

Remarks

DoAction is a generic method available in every component. 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;....

GetAttachedBytes Method (PDFVerifier Component)

Saves a PDF attachment to a byte array.

Syntax

function GetAttachedBytes(Index: Integer): TBytes;

Remarks

Use this method to retrieve the contents of an attached file as a byte array.

GetAttachedFile Method (PDFVerifier Component)

Saves a PDF attachment to a file.

Syntax

procedure GetAttachedFile(Index: Integer; Path: String);

Remarks

Use this method to retrieve the contents of an attached file and save it to a file.

GetAttachedStream Method (PDFVerifier Component)

Saves a PDF attachment to a stream.

Syntax

procedure GetAttachedStream(Index: Integer; Stream: TStream);

Remarks

Use this method to retrieve the contents of an attached file and save it to a stream.

GetSignedVersion Method (PDFVerifier Component)

Returns the part of the document that is covered by the signature.

Syntax

procedure GetSignedVersion(SigLabel: String);

Remarks

Use this method to retrieve the revision of the document that is covered by the SigLabel signature.

PDF documents often use the incremental updates approach, with any changes being appended to the document without altering the existing revision. This may lead to situations where a signature only covers a part of the document (one of the past revisions), but not the subsequent changes. This method provides means to extract the revision that is actually certified by the signature.

It is recommended that you use this method when validating signatures to make sure the signature covers what you expect it to cover.

An alternative to this method is to check the CoverageEndsAt field of the signature object and match it to the document length.

Open Method (PDFVerifier Component)

Opens a document for verifying or removing signatures.

Syntax

procedure Open(EditMode: Boolean);

Remarks

Use this method to open a document for verifying or removing signatures, or for extracting signed content. When finished, call Close to complete the operation and release any allocated resources.

Set EditMode to true to open the document in edit mode (only useful if you intend to remove signatures).

Reset Method (PDFVerifier Component)

Resets the component settings.

Syntax

procedure Reset();

Remarks

Reset is a generic method available in every component.

Revalidate Method (PDFVerifier Component)

Revalidates a signature in accordance with current settings.

Syntax

procedure Revalidate(SigLabel: String);

Remarks

Use this method to revalidate a signature in the opened PDF document.

SelectInfo Method (PDFVerifier Component)

Select signature information for a specific entity.

Syntax

procedure SelectInfo(EntityLabel: String; InfoType: Integer; ClearSelection: Boolean);

Remarks

Use this method to select (or filter) signature-related information for a specific signature element.

Provide the unique label of the entity that you are interested in via the EntityLabel parameter. Use one of the following filters, or their combination, to specify what information you are interested in:

Following the call, the relevant pieces of information will be copied to the respective component properties (Certificates, CRLs, OCSPs). Note that you can accumulate information in the properties by making repeated calls to SelectInfo and keeping ClearSelection set to false.

This method is useful if you would like to read/display detailed information about a particular signature or timestamp.

Unsign Method (PDFVerifier Component)

Deletes a signature from the document.

Syntax

procedure Unsign(SigLabel: String; UnsignKind: Integer);

Remarks

Use this method to delete an existing signature from the document. Use the SigLabel parameter to specify the signature to be removed.

Unsigning is different from GetSignedVersion. The latter returns the revision of the document including the mentioned signature (thus removing anything added after that signature was created). Unsign removes the signature completely by carving it out of the document.

The following unsign kinds are currently supported:

Note: SigLabel set to "" removes all signatures in the document.

Verify Method (PDFVerifier Component)

Verifies a signed PDF document.

Syntax

procedure Verify();

Remarks

Use this method to validate all signatures in a PDF document.

This method walks through a signed document and reports every signature via the SignatureFound event. Subscribe to the event to be notified about the signatures and adjust validation settings on the fly.

Upon completion of this method, the signature details will be published in the Signatures property.

This method only validates the signatures, but does not check their coverage. It is a good idea to use mechanisms such as GetSignedVersion or CoverageEndsAt to ensure that the signature covers the expected document revision.

ChainElementDownload Event (PDFVerifier Component)

Fires when there is a need to download a chain element from an online source.

Syntax

type TChainElementDownloadEvent = procedure (
  Sender: TObject;
  Kind: Integer;
  const CertRDN: String;
  const CACertRDN: String;
  const Location: String;
  var Action: Integer
) of Object;

property OnChainElementDownload: TChainElementDownloadEvent read FOnChainElementDownload write FOnChainElementDownload;

Remarks

Subscribe to this event to be notified about validation element retrievals. Use the Action parameter to suppress the download if required.

ChainElementNeeded Event (PDFVerifier Component)

Fires when an element required to validate the chain was not located.

Syntax

type TChainElementNeededEvent = procedure (
  Sender: TObject;
  Kind: Integer;
  const CertRDN: String;
  const CACertRDN: String
) of Object;

property OnChainElementNeeded: TChainElementNeededEvent read FOnChainElementNeeded write FOnChainElementNeeded;

Remarks

Subscribe to this event to be notified about missing validation elements. Use the KnownCRLs, KnownCertificates, and KnownOCSPs properties in the event handler to provide the missing piece.

ChainValidated Event (PDFVerifier Component)

Reports the completion of a certificate chain validation.

Syntax

type TChainValidatedEvent = procedure (
  Sender: TObject;
  Index: Integer;
  const EntityLabel: String;
  const SubjectRDN: String;
  ValidationResult: Integer;
  ValidationDetails: Integer;
  var Cancel: Boolean
) of Object;

property OnChainValidated: TChainValidatedEvent read FOnChainValidated write FOnChainValidated;

Remarks

This event is fired when a certificate chain validation routine completes. SubjectRDN identifies the owner of the validated certificate.

ValidationResult set to 0 (zero) indicates successful chain validation.

Any other value reports a failure, and ValidationDetails provides more details on its reasons.

ChainValidationProgress Event (PDFVerifier Component)

This event is fired multiple times during chain validation to report various stages of the validation procedure.

Syntax

type TChainValidationProgressEvent = procedure (
  Sender: TObject;
  const EventKind: String;
  const CertRDN: String;
  const CACertRDN: String;
  var Action: Integer
) of Object;

property OnChainValidationProgress: TChainValidationProgressEvent read FOnChainValidationProgress write FOnChainValidationProgress;

Remarks

Subscribe to this event to be notified about chain validation progress. Use the Action parameter to alter the validation flow.

The EventKind parameter reports the nature of the event being reported. The CertRDN and CACertRDN parameters report the distinguished names of the certificates that are relevant for the event invocation (one or both can be empty, depending on EventKind). Use the Action parameter to adjust the validation flow.

DocumentLoaded Event (PDFVerifier Component)

This event is fired when the document has been loaded into memory.

Syntax

type TDocumentLoadedEvent = procedure (
  Sender: TObject;
  var Cancel: Boolean
) of Object;

property OnDocumentLoaded: TDocumentLoadedEvent read FOnDocumentLoaded write FOnDocumentLoaded;

Remarks

The handler for this event is a good place to check the document structure, which may be useful when preparing the signature. For example, you can use the Pages information to find the optimal position for the signature widget.

Set Cancel to true to terminate document processing on this stage.

Encrypted Event (PDFVerifier Component)

Notifies the application that the document is encrypted and provides recipient certificate details if asymmetric encryption was used to encrypt the document.

Syntax

type TEncryptedEvent = procedure (
  Sender: TObject;
  CertUsed: Boolean;
  const IssuerRDN: String;
  const SerialNumber: TBytes;
  const SubjectKeyID: TBytes;
  NeedCredential: Boolean;
  var SkipThis: Boolean
) of Object;

property OnEncrypted: TEncryptedEvent read FOnEncrypted write FOnEncrypted;

Remarks

The component fires this event when processing encrypted documents to report the fact of encryption and pass certificate parameters to the user.

This event fires repeatedly for each encryption mechanism used in the document until the user provides the correct credential via the DecryptionCertificate or Password property (depending on the encryption method used), or sets SkipThis to true.

The CertUsed parameter specifies the encryption method used. If set to true, it indicates that the document uses asymmetric (certificate-based) encryption. In that case, the IssuerRDN, SerialNumber, and SubjectKeyID parameters provide the details of the encryption certificate. Note that the document can be encrypted with more than one certificate (or have "more than one recipient"), in which case each certificate will invoke its own Encrypted event loop.

CertUsed set to false indicates that the document uses password encryption. In this case, provide the password via the Password property.

The NeedCredential parameter specifies whether the correct credential is already available to the component or still needs to be set. One example where NeedCredential would be set to false is where it had been provided by the application prior to processing the document (e.g. by setting the Password property to a known pre-defined value). If NeedCredential is set to true, you must provide the valid credential for the decryption process to succeed.

Error Event (PDFVerifier Component)

Information about errors during signing/validation.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

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

ErrorCode contains an error code and Description contains a textual description of the error.

Notification Event (PDFVerifier Component)

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

Syntax

type TNotificationEvent = procedure (
  Sender: TObject;
  const EventID: String;
  const EventParam: String
) of Object;

property OnNotification: TNotificationEvent read FOnNotification write FOnNotification;

Remarks

The component fires this event to let the application know about some event, occurrence, or milestone in the component. 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 component, the exact action it is performing, or the document being processed, one or both may be omitted.

This component can fire this event with the following EventID values:

SignatureFound Event (PDFVerifier Component)

Signifies the start of signature validation.

Syntax

type TSignatureFoundEvent = procedure (
  Sender: TObject;
  Index: Integer;
  const EntityLabel: String;
  const IssuerRDN: String;
  const SerialNumber: TBytes;
  const SubjectKeyID: TBytes;
  CertFound: Boolean;
  var ValidateSignature: Boolean;
  var ValidateChain: Boolean
) of Object;

property OnSignatureFound: TSignatureFoundEvent read FOnSignatureFound write FOnSignatureFound;

Remarks

This event tells the application that signature validation is about to start, and provides the details about the signer's certificate via its IssuerRDN, SerialNumber, and SubjectKeyID parameters. It fires for every signature located in the verified document or message.

The CertFound parameter is set to True if the component has found the needed certificate in one of the known locations, and to False otherwise, in which case you must provide it manually via the KnownCertificates property.

Signature validation consists of two independent stages: cryptographic signature validation and chain validation. Separate validation results are reported for each, with the SignatureValidationResult and ChainValidationResult properties respectively.

Use the ValidateSignature and ValidateChain parameters to tell the verifier which stages to include in the validation.

SignatureValidated Event (PDFVerifier Component)

Marks the completion of the signature validation routine.

Syntax

type TSignatureValidatedEvent = procedure (
  Sender: TObject;
  Index: Integer;
  const EntityLabel: String;
  const IssuerRDN: String;
  const SerialNumber: TBytes;
  const SubjectKeyID: TBytes;
  ValidationResult: Integer;
  var Cancel: Boolean
) of Object;

property OnSignatureValidated: TSignatureValidatedEvent read FOnSignatureValidated write FOnSignatureValidated;

Remarks

This event is fired upon the completion of the signature validation routine, and reports the respective validation result.

Use the IssuerRDN, SerialNumber, and/or SubjectKeyID parameters to identify the signing certificate.

ValidationResult is set to 0 if the validation has been successful, or to a non-zero value in case of a validation failure.

TimestampFound Event (PDFVerifier Component)

Signifies the start of a timestamp validation routine.

Syntax

type TTimestampFoundEvent = procedure (
  Sender: TObject;
  Index: Integer;
  const EntityLabel: String;
  const IssuerRDN: String;
  const SerialNumber: TBytes;
  const SubjectKeyID: TBytes;
  CertFound: Boolean;
  var ValidateTimestamp: Boolean;
  var ValidateChain: Boolean
) of Object;

property OnTimestampFound: TTimestampFoundEvent read FOnTimestampFound write FOnTimestampFound;

Remarks

This event fires for every timestamp identified during signature processing, and reports the details about the signer's certificate via its IssuerRDN, SerialNumber, and SubjectKeyID parameters.

The CertFound parameter is set to True if the component has found the needed certificate in one of the known locations, and to False otherwise, in which case you must provide it manually via the KnownCertificates property.

Just like with signature validation, timestamp validation consists of two independent stages: cryptographic signature validation and chain validation. Separate validation results are reported for each, with the ValidationResult and ChainValidationResult properties respectively.

Use the ValidateSignature and ValidateChain parameters to tell the verifier which stages to include in the validation.

TimestampValidated Event (PDFVerifier Component)

Reports the completion of the timestamp validation routine.

Syntax

type TTimestampValidatedEvent = procedure (
  Sender: TObject;
  Index: Integer;
  const EntityLabel: String;
  const IssuerRDN: String;
  const SerialNumber: TBytes;
  const SubjectKeyID: TBytes;
  const Time: String;
  ValidationResult: Integer;
  ChainValidationResult: Integer;
  ChainValidationDetails: Integer;
  var Cancel: Boolean
) of Object;

property OnTimestampValidated: TTimestampValidatedEvent read FOnTimestampValidated write FOnTimestampValidated;

Remarks

This event is fired upon the completion of the timestamp validation routine, and reports the respective validation result.

ValidationResult is set to 0 if the validation has been successful, or to a non-zero value in case of a failure.

TLSCertNeeded Event (PDFVerifier Component)

Fires when a remote TLS party requests a client certificate.

Syntax

type TTLSCertNeededEvent = procedure (
  Sender: TObject;
  const Host: String;
  const CANames: String
) of Object;

property OnTLSCertNeeded: TTLSCertNeededEvent read FOnTLSCertNeeded write FOnTLSCertNeeded;

Remarks

This event fires to notify the implementation that a remote TLS server has requested a client certificate. The Host parameter identifies the host that makes a request, and the CANames parameter (optional, according to the TLS spec) advises on the accepted issuing CAs.

Use the TLSClientChain property in response to this event to provide the requested certificate. Please make sure the client certificate includes the associated private key. Note that you may set the certificates before the connection without waiting for this event to fire.

This event is preceded by the TLSHandshake event for the given host and, if the certificate was accepted, succeeded by the TLSEstablished event.

TLSCertValidate Event (PDFVerifier Component)

This event is fired upon receipt of the TLS server's certificate, allowing the user to control its acceptance.

Syntax

type TTLSCertValidateEvent = procedure (
  Sender: TObject;
  const ServerHost: String;
  const ServerIP: String;
  var Accept: Boolean
) of Object;

property OnTLSCertValidate: TTLSCertValidateEvent read FOnTLSCertValidate write FOnTLSCertValidate;

Remarks

This event is fired during a TLS handshake. Use the TLSServerChain property to access the certificate chain. In general, components may contact a number of TLS endpoints during their work, depending on their configuration.

Accept is assigned in accordance with the outcome of the internal validation check performed by the component, and can be adjusted if needed.

TLSEstablished Event (PDFVerifier Component)

Fires when a TLS handshake with Host successfully completes.

Syntax

type TTLSEstablishedEvent = procedure (
  Sender: TObject;
  const Host: String;
  const Version: String;
  const Ciphersuite: String;
  const ConnectionId: TBytes;
  var Abort: Boolean
) of Object;

property OnTLSEstablished: TTLSEstablishedEvent read FOnTLSEstablished write FOnTLSEstablished;

Remarks

The component uses this event to notify the application about a successful completion of a TLS handshake.

The Version, Ciphersuite, and ConnectionId parameters indicate the security parameters of the new connection. Use the Abort parameter if you need to terminate the connection at this stage.

TLSHandshake Event (PDFVerifier Component)

Fires when a new TLS handshake is initiated, before the handshake commences.

Syntax

type TTLSHandshakeEvent = procedure (
  Sender: TObject;
  const Host: String;
  var Abort: Boolean
) of Object;

property OnTLSHandshake: TTLSHandshakeEvent read FOnTLSHandshake write FOnTLSHandshake;

Remarks

The component uses this event to notify the application about the start of a new TLS handshake to Host. If the handshake is successful, this event will be followed by the TLSEstablished event. If the server chooses to request a client certificate, the TLSCertNeeded event will also be fired.

TLSShutdown Event (PDFVerifier Component)

Reports the graceful closure of a TLS connection.

Syntax

type TTLSShutdownEvent = procedure (
  Sender: TObject;
  const Host: String
) of Object;

property OnTLSShutdown: TTLSShutdownEvent read FOnTLSShutdown write FOnTLSShutdown;

Remarks

This event notifies the application about the closure of an earlier established TLS connection. Note that only graceful connection closures are reported.

Certificate Type

Encapsulates an individual X.509 certificate.

Remarks

This type keeps and provides access to X.509 certificate details.

Fields

Constructors

>

constructor Create();

CRL Type

Represents a Certificate Revocation List.

Remarks

CRLs store information about revoked certificates, i.e., certificates that have been identified as invalid by their issuing certificate authority (CA) for any number of reasons.

Each CRL object lists certificates from a single CA and identifies them by their serial numbers. A CA may or may not publish a CRL, may publish several CRLs, or may publish the same CRL in multiple locations.

Unlike OCSP responses, CRLs only list certificates that have been revoked. They do not list certificates that are still valid.

Fields

Constructors

>

constructor Create();

MailAttachment Type

Represents an attachment to an e-mail message.

Remarks

This object is a container for message attachments.

Fields

Constructors

>

constructor Create(valContentType: String);

OCSPResponse Type

Represents a single OCSP response originating from an OCSP responder.

Remarks

OCSP is a protocol that allows verification of certificate status in real-time, and is an alternative to Certificate Revocation Lists (CRLs).

An OCSP response is a snapshot of the certificate status at a given time.

Fields

Constructors

>

constructor Create();

PDFDocumentInfo Type

Contains document security information.

Remarks

This type provides an overview of the document security parameters, including the encryption method (if used) and signature count. This information is available early into the signing/validation process and lets you prepare for the subsequent signature validation.

Fields

Constructors

>

constructor Create();

PDFPage Type

This component is a container for PDF page details.

Remarks

Use this object to read general information about a document page, such as its dimensions and content positioning details.

Fields

Constructors

>

constructor Create();

PDFSignature Type

This component is a container for PDF signature details.

Remarks

Use it to tune up signature properties and widget appearance when creating a signature, or to read the signature information when processing it.

Fields

Constructors

>

constructor Create();

ProxySettings Type

A container for proxy server settings.

Remarks

This type exposes a collection of properties for tuning up the proxy server configuration.

Fields

Constructors

>

constructor Create();

SocketSettings Type

A container for the socket settings.

Remarks

This type is a container for socket-layer parameters.

Fields

Constructors

>

constructor Create();

TimestampInfo Type

A container for timestamp information.

Remarks

The TimestampInfo object contains details of a third-party timestamp and the outcome of its validation.

Fields

Constructors

>

constructor Create();

TLSSettings Type

A container for TLS connection settings.

Remarks

The TLS (Transport Layer Security) protocol provides security for information exchanged over insecure connections such as TCP/IP.

Fields

Constructors

>

constructor Create();

Config Settings (PDFVerifier Component)

The component 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 component, access to these internal properties is provided through the Config method.

PDFVerifier Config Settings

Base Config Settings

Trappable Errors (PDFVerifier Component)

PDFVerifier Errors