PDFSigner Component

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The PDFSigner component signs PDF documents digitally.

Syntax

nsoftware.SecureBlackbox.Pdfsigner

Remarks

PDFSigner can sign PDF documents in accordance with a selection of PDF and PAdES signature standards.

Standards and technologies supported

PDFSigner can create PDF signatures that match the following baseline standards:

• Generic PDF signatures (ISO 32000)
• PAdES: all profiles are supported (BES, EPES, T, LTV, B-B, B-T, and others) (ETSI EN 319 142-1 and others)
• Signature and document timestamps using external TSAs.
• All industry-standard cryptographic algorithms (RSA, ECDSA, SHA256-512, and many others).

Configuring the signature spec

Configuring PDFSigner to produce signatures of the right type is one of the most important questions you need to address. Normally the service or software you will be communicating your PDF documents to will provide you with the list of requirements that your signatures should match.

Typically, those will dictate the following key aspects of the signatures:

• Level (BES, T, or LTV). This can be adjusted with the Level property (Note: when creating EPES signatures you need to provide the signature PolicyID and PolicyHash properties).
• Timestamp requirement: provide the address of your online TSA service via the TimestampServer property.
• When creating LTV signatures, tune up validation parameters via the RevocationCheck, OfflineMode, and IgnoreChainValidationErrors properties.
• To create a document timestamp, sign your document first, and then sign the result again with Level set to pslDocumentTimestamp and TimestampServer pointing to the TSA URL.

Signing certificates

PDFSigner can use certificates residing on different media. Besides generic certificates stored in PFX or PEM files (A1), it can operate with non-exportable certificates residing on hardware media (A3) or in the cloud.

Non-exportable certificates can be accessed transparently via a Windows CSP or a PKCS#11 driver, if supplied by the certificate issuer. Proprietary interfaces can be plugged in with the external signing feature (see below).

You can use the CertificateManager and CertificateStorage components to load the signing certificate. Assign the certificate to the SigningCertificate property, and optionally provide the remainder of its chain via the SigningChain property.

Note: If signing with a non-exportable key (such as residing on a hardware device or in the cloud), please make sure you keep the original CertificateStorage object open until the signing is completed. This is because the storage component provides a 'bridge' to the private key. If the storage is closed prematurely, this bridge is destroyed, and the private key can't be used.

You don't need to provide a signing certificate or chain when creating document timestamp signatures, since this type of signature is done with a TSA's certificate.

Widget adjustment

PDFSigner provides means to customize the look of the signature widget to be shown on the document page. Create your very own signatures in the form of your company's logo, a handwritten signature, or a wet seal.

Alternatively, you can choose not to associate any widget with your signature by setting Invisible to true.

Please check out this self-describing PDF document for good guidance on widget positioning, background styles, and text formatting.

Signing the document

Now that you have set up all signature, certificate, and widget properties, it is time to sign. You can provide the input document in one of the following forms: as a file (assign the path to the InputFile property), as a stream (assign to the InputStream property), or as a byte array (assign to InputBytes). Similarly, the output can be collected in one of the same forms, either by passing the destination path or stream via OutputFile and OutputStream respectively, or by reading the resulting document bytes from the OutputBytes property after the signing.

Having set up the input and output, call the component's Sign method. This will initiate the signing process. Depending on the settings, the signing may be as straightforward as calculating the document hash and signing it with the private key (e.g. in the PAdES-BES signing variant), or it may involve advanced chain validation routines (PAdES-LTV). During the latter, the component may contact a number of external revocation information sources (CRL and OCSP servers) to establish the validity of the signing certificate.

If a TSA server was provided via the TimestampServer property, the component will contact it too to timestamp the new signature.

During the signing, PDFSigner may fire events to let your code know of certain conditions. If the input document is encrypted but no decryption parameters were found in the Password and DecryptionCertificate properties, the component will fire the Encrypted event to tell your code that it needs decryption information to be able to continue with the signing. It may fire TLSCertValidate if one of the HTTP endpoints involved during the operation (which may be a CRL, OCSP, or TSA service) works over TLS and needs its certificate to be validated.

External signing and DCAuth

PDFSigner, like many other components offered by the product, supports two methods of signing with external keys. These methods are fully independent of each other: you can choose the one that suits your usage scenario best.

Synchronous method: ExternalSign

This is a simpler method that basically lets you infiltrate into the heart of the signing routine by taking care of the hash signing operation. The component does the rest of the job (hash calculation, preparation of signature objects, CRL/OCSP retrieval).

To initiate this method, call SignExternal instead of Sign. When the hash is ready, it will be passed back to your code with the ExternalSign event. Your event handler needs to sign the hash with the private key and return the created signature back to the component - which will embed it into the document.

You don't need your signing certificate to contain an associated private key when using this method. The certificate itself (its public copy) may be needed though, as it is often included in the hash calculation.

This method is synchronous, meaning SignExternal provides you the results immediately upon its completion.

Asynchronous method: DCAuth

DCAuth is a SecureBlackbox know-how technology. This protocol was designed to allow sharing of private keys across environments, allowing the signer and the private key to reside on different systems. It works in the following way:

• The signing party - such as PDFSigner - initiates the operation using a SignAsyncBegin call. This produces two outcomes: a pre-signed document (a document with a blank signature placeholder), and a request state (an object containing a hash that needs to be signed). At this point the PDFSigner instance can be released, and the process itself terminated (which may be useful when run as part of a web page).
• The request state is passed to the private key holder party. The private key holder passes the request state to a DCAuth object, which parses the request state, extracts the hash, and signs it. The output of DCAuth processing is another object, a response state, which contains the signature. The private key holder then sends the response state back to the signing party.
• The signing party re-creates the components and passes the response state, together with the pre-signed version of the document, to the signer's SignAsyncEnd method. SignAsyncEnd extracts the signature from the response state and incorporates it into the pre-signed document.

This method is asynchronous in that sense that from the signing party's viewpoint, it splits the signing operation into the pre-signing and completion stages which can be performed independently from each other and in different execution contexts. This makes this method particularly helpful for use in web pages and other scenarios where the signing key is not available in real time.

Fine-grained chain validation setup

Chain validation is a sophisticated, multi-faceted procedure that involves a lot of variables. Depending on the configuration of your operating environment, the specifics of the PKI framework being used, and the validation policy you need to follow, you may want to tune up your chain validation parameters so they fit them best. A summary of such parameters is given below.

• RevocationCheck lets you choose between and/or prioritize revocation origins. OCSP sources are often preferred to CRL because of their real-time capability and the smaller size of validation tokens they produce.
• OfflineMode is a master switch that stops the component from looking for any validation tokens online. If this property is switched on, the component will only use the KnownCertificates, TrustedCertificates, KnownCRLs, and KnownOCSPs collections to look for the missing validation material.
• IgnoreChainValidationErrors makes the component ignore any major validation issues it encounters (such us an untrusted chain or missing CRL). This option is handy for debugging and for creating signatures in the environments where the signing certificate is not trusted.
• KnownCertificates, KnownCRLs, and KnownOCSPs let you provide your own validation material. This may be useful when working in OfflineMode, where the signer has no access to the validation sources, or where the validation material has already been collected.
• TrustedCertificates lets you provide a list of trust anchors, either as a complement to the system's or as an alternative to it.
• BlockedCertificates lets you provide a list of blocked/distrusted certificates. Any CA certificate contained in it will be deemed untrusted/invalid.

The following parameters are not directly related to chain validation, but may have an implicit effect on it.

• Proxy, SocketSettings, and TLSSettings let you tune up the connectivity and TLS options in accordance with local preferences.
• TLSClientChain lets you provide the client certificate and its chain for TLS client authentication.
• Subscribe to TLSCertValidate to validate any TLS certificates of the services involved in chain validation.

The results of the chain validation procedure, upon its completion, are published in the following properties:

• ChainValidationResult contains the primary result of the chain validation routine: valid, valid but untrusted, invalid, or undefined.
• ChainValidationDetails provides the details of the factors that contributed to the chain validation result, such as an outdated certificate, a missing CRL, or a missing CA certificate.
• ValidationLog contains the detailed chain validation log. The log can often be very helpful in nailing down various validation issues.

Property List

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

Method List

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

Event List

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

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

AttachedFiles Property (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public MailAttachmentList AttachedFiles { get; }

Public ReadOnly Property AttachedFiles As MailAttachmentList

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.

AutoValidateSignatures Property (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public bool AutoValidateSignatures { get; set; }

Public Property AutoValidateSignatures As Boolean

Default Value

False

Remarks

This setting is switched off by default to speed up document processing. Even if the document is loaded with this property set to false, you can validate the signatures manually on a later stage using the Revalidate method.

BlockedCertificates Property (PDFSigner Component)

The certificates that must be rejected as trust anchors.

Syntax

• C#
• VB.NET

public CertificateList BlockedCertificates { get; }

Public Property BlockedCertificates As CertificateList

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.

Certificates Property (PDFSigner Component)

A collection of certificates included in the electronic signature.

Syntax

• C#
• VB.NET

public CertificateList Certificates { get; }

Public ReadOnly Property Certificates As CertificateList

Remarks

Use this property to access all certificates included into the signature(s) by its creator.

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

CRLs Property (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public CRLList CRLs { get; }

Public ReadOnly Property CRLs As CRLList

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.

DecryptionCertificate Property (PDFSigner Component)

A decryption certificate.

Syntax

• C#
• VB.NET

public Certificate DecryptionCertificate { get; set; }

Public Property DecryptionCertificate As Certificate

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.

DocumentInfo Property (PDFSigner Component)

Contains information about the document properties.

Syntax

• C#
• VB.NET

public PDFDocumentInfo DocumentInfo { get; }

Public ReadOnly Property DocumentInfo As PDFDocumentInfo

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.

EmptyFieldIndex Property (PDFSigner Component)

Specifies the index of the empty signature field to sign.

Syntax

• C#
• VB.NET

public int EmptyFieldIndex { get; set; }

Public Property EmptyFieldIndex As Integer

Default Value

-1

Remarks

Use this property to specify the empty form field that should be signed. If the default value of -1 is assigned to this property, a new signature field will be created.

ExternalCrypto Property (PDFSigner Component)

Provides access to external signing and DC parameters.

Syntax

• C#
• VB.NET

public ExternalCrypto ExternalCrypto { get; }

Public ReadOnly Property ExternalCrypto As ExternalCrypto

Remarks

Use this property to tune-up remote cryptography settings. SecureBlackbox supports two independent types of external cryptography: synchronous (based on the ExternalSign event) and asynchronous (based on the DC protocol and the DCAuth signing component).

This property is read-only.

FIPSMode Property (PDFSigner Component)

Reserved.

Syntax

• C#
• VB.NET

public bool FIPSMode { get; set; }

Public Property FIPSMode As Boolean

Default Value

False

Remarks

This property is reserved for future use.

IgnoreChainValidationErrors Property (PDFSigner Component)

Makes the component tolerant to chain validation errors.

Syntax

• C#
• VB.NET

public bool IgnoreChainValidationErrors { get; set; }

Public Property IgnoreChainValidationErrors As Boolean

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 (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public byte[] InputBytes { get; set; }

Public Property InputBytes As Byte()

Remarks

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

This property is not available at design time.

InputFile Property (PDFSigner Component)

The PDF file to be signed or updated.

Syntax

• C#
• VB.NET

public string InputFile { get; set; }

Public Property InputFile As String

Default Value

""

Remarks

Use this property to provide a path to the PDF document to be signed or updated, or to the pre-signed copy expected by SignAsyncEnd.

InputStream Property (PDFSigner Component)

A stream containing the PDF document to be signed or updated.

Syntax

• C#
• VB.NET

public System.IO.Stream InputStream { get; set; }

Public Property InputStream As System.IO.Stream

Default Value

null

Remarks

Use this property to provide the PDF document to be signed or updated, or the pre-signed copy expected by SignAsyncEnd.

This property is not available at design time.

KnownCertificates Property (PDFSigner Component)

Additional certificates for chain validation.

Syntax

• C#
• VB.NET

public CertificateList KnownCertificates { get; }

Public Property KnownCertificates As CertificateList

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.

KnownCRLs Property (PDFSigner Component)

Additional CRLs for chain validation.

Syntax

• C#
• VB.NET

public CRLList KnownCRLs { get; }

Public Property KnownCRLs As CRLList

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.

KnownOCSPs Property (PDFSigner Component)

Additional OCSP responses for chain validation.

Syntax

• C#
• VB.NET

public OCSPResponseList KnownOCSPs { get; }

Public Property KnownOCSPs As OCSPResponseList

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.

NewSignature Property (PDFSigner Component)

Provides access to new signature properties.

Syntax

• C#
• VB.NET

public PDFSignature NewSignature { get; }

Public ReadOnly Property NewSignature As PDFSignature

Remarks

Use this property to tune-up signature properties. Use the Widget object to tune up visual parameters of the signature widget.

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

OCSPs Property (PDFSigner Component)

A collection of OCSP responses embedded into the signature.

Syntax

• C#
• VB.NET

public OCSPResponseList OCSPs { get; }

Public ReadOnly Property OCSPs As OCSPResponseList

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.

OfflineMode Property (PDFSigner Component)

Switches the component to offline mode.

Syntax

• C#
• VB.NET

public bool OfflineMode { get; set; }

Public Property OfflineMode As Boolean

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 (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public byte[] OutputBytes { get; }

Public ReadOnly Property OutputBytes As Byte()

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 (PDFSigner Component)

The file to save the signed or updated document to.

Syntax

• C#
• VB.NET

public string OutputFile { get; set; }

Public Property OutputFile As String

Default Value

""

Remarks

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

OutputStream Property (PDFSigner Component)

The stream to write the signed document to.

Syntax

• C#
• VB.NET

public System.IO.Stream OutputStream { get; set; }

Public Property OutputStream As System.IO.Stream

Default Value

null

Remarks

Use this property to provide a stream where the resulting PDF document should be written to.

This property is not available at design time.

Pages Property (PDFSigner Component)

A list of pages contained in the document.

Syntax

• C#
• VB.NET

public PDFPageList Pages { get; }

Public ReadOnly Property Pages As PDFPageList

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.

Password Property (PDFSigner Component)

The decryption password.

Syntax

• C#
• VB.NET

public string Password { get; set; }

Public Property Password As String

Default Value

""

Remarks

Use this property to provide the decryption password.

Profile Property (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public string Profile { get; set; }

Public Property Profile As String

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.

Supported profiles:

The "PAdES.BASELINE-B" profile is equivalent to the following settings: Signer.NewSignature.Level = PDFSignatureLevels.pslBES; Signer.Config("AutoCollectRevocationInfo=false"); This code uses the PAdES-BES form (a signature that does not incorporate the signature-policy-identifier). Alternatively, you can use the PAdES-EPES form (a signature that does incorporate the signature-policy-identifier) with the following code modification: Signer.NewSignature.Level = PDFSignatureLevels.pslEPES;

The "PAdES.BASELINE-T" profile extends the "PAdES.BASELINE-B" profile with the following settings: Signer.TimestampServer = "https://freetsa.org/tsr";

The "PAdES.BASELINE-LT.Update" profile is applied in the Update method. It extends the signature created using the PAdES B-T level ("PAdES.BASELINE-T" profile). Signer.Config("AutoCollectRevocationInfo=true");

The "PAdES.BASELINE-LTA.Update" profile is applied in the Update method. It extends the signature created using the PAdES B-T level ("PAdES.BASELINE-T" profile). Signer.Config("AutoCollectRevocationInfo=true"); Signer.TimestampServer = "https://freetsa.org/tsr";

Proxy Property (PDFSigner Component)

The proxy server settings.

Syntax

• C#
• VB.NET

public ProxySettings Proxy { get; }

Public ReadOnly Property Proxy As ProxySettings

Remarks

Use this property to tune up the proxy server settings.

This property is read-only.

RevocationCheck Property (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public PdfsignerRevocationChecks RevocationCheck { get; set; }

enum PdfsignerRevocationChecks {
  crcNone,
  crcAuto,
  crcAllCRL,
  crcAllOCSP,
  crcAllCRLAndOCSP,
  crcAnyCRL,
  crcAnyOCSP,
  crcAnyCRLOrOCSP,
  crcAnyOCSPOrCRL
}

Public Property RevocationCheck As PdfsignerRevocationChecks

Enum PdfsignerRevocationChecks
  crcNone
  crcAuto
  crcAllCRL
  crcAllOCSP
  crcAllCRLAndOCSP
  crcAnyCRL
  crcAnyOCSP
  crcAnyCRLOrOCSP
  crcAnyOCSPOrCRL
End Enum

Default Value

1

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 (PDFSigner Component)

Provides details of all signatures and empty fields found in the PDF document.

Syntax

• C#
• VB.NET

public PDFSignatureList Signatures { get; }

Public ReadOnly Property Signatures As PDFSignatureList

Remarks

Use this property to get the details of all the signatures and empty signature fields identified in the document.

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

SigningCertificate Property (PDFSigner Component)

The certificate to be used for signing.

Syntax

• C#
• VB.NET

public Certificate SigningCertificate { get; set; }

Public Property SigningCertificate As Certificate

Remarks

Use this property to specify the certificate that shall be used for signing the data. Note that this certificate should have a private key associated with it. Use SigningChain to supply the rest of the certificate chain for inclusion into the signature.

This property is not available at design time.

SigningChain Property (PDFSigner Component)

The signing certificate chain.

Syntax

• C#
• VB.NET

public CertificateList SigningChain { get; }

Public Property SigningChain As CertificateList

Remarks

Use this property to provide the chain for the signing certificate. Use the SigningCertificate property, if it is available, to provide the signing certificate itself.

This property is not available at design time.

SocketSettings Property (PDFSigner Component)

Manages network connection settings.

Syntax

• C#
• VB.NET

public SocketSettings SocketSettings { get; }

Public ReadOnly Property SocketSettings As SocketSettings

Remarks

Use this property to tune up network connection parameters.

This property is read-only.

Timestamps Property (PDFSigner Component)

Contains a collection of timestamps for the processed document.

Syntax

• C#
• VB.NET

public TimestampInfoList Timestamps { get; }

Public ReadOnly Property Timestamps As TimestampInfoList

Remarks

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

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

TimestampServer Property (PDFSigner Component)

The address of the timestamping server.

Syntax

• C#
• VB.NET

public string TimestampServer { get; set; }

Public Property TimestampServer As String

Default Value

""

Remarks

Use this property to set the address of the TSA (Time Stamping Authority) server to use for timestamping the signature (normal signing) or the document (LTV update).

If your timestamping service enforces credential-based user authentication (basic or digest), you can provide the credentials in the same URL:

http://user:password@timestamp.server.com/TsaService

For TSAs using certificate-based TLS authentication, provide the client certificate via the TLSClientChain property.

TLSClientChain Property (PDFSigner Component)

The TLS client certificate chain.

Syntax

• C#
• VB.NET

public CertificateList TLSClientChain { get; }

Public Property TLSClientChain As CertificateList

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.

TLSServerChain Property (PDFSigner Component)

The TLS server's certificate chain.

Syntax

• C#
• VB.NET

public CertificateList TLSServerChain { get; }

Public ReadOnly Property TLSServerChain As CertificateList

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.

TLSSettings Property (PDFSigner Component)

Manages TLS layer settings.

Syntax

• C#
• VB.NET

public TLSSettings TLSSettings { get; }

Public ReadOnly Property TLSSettings As TLSSettings

Remarks

Use this property to tune up the TLS layer parameters.

This property is read-only.

TrustedCertificates Property (PDFSigner Component)

A list of trusted certificates for chain validation.

Syntax

• C#
• VB.NET

public CertificateList TrustedCertificates { get; }

Public Property TrustedCertificates As CertificateList

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.

ValidationMoment Property (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public string ValidationMoment { get; set; }

Public Property ValidationMoment As String

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.

Widget Property (PDFSigner Component)

Provides access to signature widget properties.

Syntax

• C#
• VB.NET

public PDFWidget Widget { get; }

Public ReadOnly Property Widget As PDFWidget

Remarks

Use this property to adjust the signature widget appearance parameters, such as background or texts.

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

AddWidgetCustomData Method (PDFSigner Component)

Adds a custom data to the signature widget.

Syntax

• C#
• VB.NET

public int AddWidgetCustomData(string customData);

Public Function AddWidgetCustomData(ByVal CustomData As String) As Integer

Remarks

Use this method to quickly add a custom data block that contains PDF graphics operators to your signature widget.

The method returns the index of the new custom text in the CustomText collection (accessed via Config).

AddWidgetText Method (PDFSigner Component)

Adds a text block to the signature widget.

Syntax

• C#
• VB.NET

public int AddWidgetText(string text, int X, int Y, string fontSize);

Public Function AddWidgetText(ByVal Text As String, ByVal X As Integer, ByVal Y As Integer, ByVal FontSize As String) As Integer

Remarks

Use this method to quickly add a custom text block to your signature widget.

The method returns the index of the new custom text in the CustomText collection (accessed via Config).

AddWidgetTextEx Method (PDFSigner Component)

Adds a text block to the signature widget.

Syntax

• C#
• VB.NET

public int AddWidgetTextEx(string text, string settings);

Public Function AddWidgetTextEx(ByVal Text As String, ByVal Settings As String) As Integer

Remarks

Use this method to add a custom text block to your signature widget.

Text represents the text string to add. Settings contains a list of parameters in the form of PARAM1=VALUE1;PARAM2=VALUE2;... or in JSON format.

The following parameters are supported:

The method returns the index of the new custom text in the CustomText collection (accessed via Config).

AttachBytes Method (PDFSigner Component)

Adds an attachment to the PDF document.

Syntax

• C#
• VB.NET

public void AttachBytes(byte[] data, string objName, string fileName, string description, string subType, string CDate, string MDate);

Public Sub AttachBytes(ByVal Data As Byte(), ByVal ObjName As String, ByVal FileName As String, ByVal Description As String, ByVal SubType As String, ByVal CDate As String, ByVal MDate As String)

Remarks

Use this method to add an attachment (embedded file) to a PDF document.

AttachFile Method (PDFSigner Component)

Adds an attachment to the PDF document.

Syntax

• C#
• VB.NET

public void AttachFile(string path, string objName, string fileName, string description, string subType, string CDate, string MDate);

Public Sub AttachFile(ByVal Path As String, ByVal ObjName As String, ByVal FileName As String, ByVal Description As String, ByVal SubType As String, ByVal CDate As String, ByVal MDate As String)

Remarks

Use this method to add an attachment (embedded file) to a PDF document.

AttachStream Method (PDFSigner Component)

Adds an attachment to the PDF document.

Syntax

• C#
• VB.NET

public void AttachStream(System.IO.Stream stream, string objName, string fileName, string description, string subType, string CDate, string MDate);

Public Sub AttachStream(ByVal Stream As System.IO.Stream, ByVal ObjName As String, ByVal FileName As String, ByVal Description As String, ByVal SubType As String, ByVal CDate As String, ByVal MDate As String)

Remarks

Use this method to add an attachment (embedded file) to a PDF document.

Close Method (PDFSigner Component)

Closes an opened document.

Syntax

• C#
• VB.NET

public void Close(bool saveChanges);

Public Sub Close(ByVal SaveChanges As Boolean)

Remarks

Use this method to close a previously opened document. Set SaveChanges to true to apply any changes made.

Config Method (PDFSigner Component)

Sets or retrieves a configuration setting.

Syntax

• C#
• VB.NET

public string Config(string configurationString);

Public Function Config(ByVal ConfigurationString As String) As 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 (PDFSigner Component)

Performs an additional action.

Syntax

• C#
• VB.NET

public string DoAction(string actionID, string actionParams);

Public Function DoAction(ByVal ActionID As String, ByVal ActionParams As String) As 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;....

Supported ActionIDs:

Use "AddImage" action to add an image to the foreground layer. The following parameters are supported:

Parameters ImageData, ImageWidth, ImageHeight, ImageType, X, Y, Width and Height are required.

Sample code to add a JPEG image of size 100px x 100px and place it in position (10, 10) with an image size (30, 30): Signer.DoAction("AddImage", "ImageData=" + Utils.HexEncode(BinaryImageData) + "; ImageWidth=100; ImageHeight=100; ImageType=jpeg; X=10; Y=10; Width=30; Height=30");

Use "GetTextWidth" action to calculate the width of the given text for a specific font. The following parameters are supported:

Sample code: Signer.DoAction("GetTextWidth", "Text=Lorem Ipsum; FontSize=10; FontName=Arial Bold Italic");

Use "GetSystemFontNames" action to get a CRLF-separated list of system TrueType font names that the component supports.

Use "IsAllGlyphsAvailable" action to check if all glyphs that correspond to the given text are available for a specific font. The following parameters are required:

For standard Type 1 fonts this action always returns a "true" value.

ExtractAsyncData Method (PDFSigner Component)

Extracts user data from the DC signing service response.

Syntax

• C#
• VB.NET

public string ExtractAsyncData(string asyncReply);

Public Function ExtractAsyncData(ByVal AsyncReply As String) As String

Remarks

Call this method before finalizing the asynchronous signing process to extract the data passed to the ExternalCrypto.Data property on the pre-signing stage.

The Data parameter can be used to pass some state or document identifier along with the signing request from the pre-signing to the completion async stage.

GetAttachedBytes Method (PDFSigner Component)

Saves a PDF attachment to a byte array.

Syntax

• C#
• VB.NET

public byte[] GetAttachedBytes(int index);

Public Function GetAttachedBytes(ByVal Index As Integer) As Byte()

Remarks

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

GetAttachedFile Method (PDFSigner Component)

Saves a PDF attachment to a file.

Syntax

• C#
• VB.NET

public void GetAttachedFile(int index, string path);

Public Sub GetAttachedFile(ByVal Index As Integer, ByVal Path As String)

Remarks

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

GetAttachedStream Method (PDFSigner Component)

Saves a PDF attachment to a stream.

Syntax

• C#
• VB.NET

public void GetAttachedStream(int index, System.IO.Stream stream);

Public Sub GetAttachedStream(ByVal Index As Integer, ByVal Stream As System.IO.Stream)

Remarks

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

Open Method (PDFSigner Component)

Opens a document for signing or updating.

Syntax

• C#
• VB.NET

public void Open();

Public Sub Open()

Remarks

Use this method to open a document for signing or updating. When finished, call Close to complete or discard the operation.

Revalidate Method (PDFSigner Component)

Revalidates a signature in accordance with current settings.

Syntax

• C#
• VB.NET

public void Revalidate(int index);

Public Sub Revalidate(ByVal Index As Integer)

Remarks

Use this method to re-validate a signature in the opened PDF document.

Sign Method (PDFSigner Component)

Signs a PDF document.

Syntax

• C#
• VB.NET

public void Sign();

Public Sub Sign()

Remarks

Call this method to sign the document referenced by the InputFile (or InputStream) property. The document will be signed with SigningCertificate as configured in NewSignature, and saved in OutputFile (OutputStream).

Use TrustedCertificates, KnownCertificates, RevocationCheck, OfflineMode and other properties of the component to adjust chain validation parameters. After the signing, the chain validation log will be available in the ValidationLog property.

SignAsyncBegin Method (PDFSigner Component)

Initiates the asynchronous signing operation.

Syntax

• C#
• VB.NET

public string SignAsyncBegin();

Public Function SignAsyncBegin() As String

Remarks

When using the DC framework, call this method to initiate the asynchronous signing process. Upon completion, a pre-signed copy of the document will be saved in OutputFile (or OutputStream). Keep the pre-signed copy somewhere local, and pass the returned string ('the request state') to the DC processor for handling.

Upon receiving the response state from the DC processor, assign the path to the pre-signed copy to InputFile (or InputStream), and call SignAsyncEnd to finalize the signing.

Note that depending on the signing method and DC configuration used, you may still need to provide the public part of the signing certificate via the SigningCertificate property.

Use the ExternalCrypto.AsyncDocumentID property to supply a unique document ID to include in the request. This is helpful when creating batches of multiple async requests, as it allows you to pass the whole response batch to SignAsyncEnd and expect it to recover the correct response from the batch automatically.

AsyncState is a message of the distributed cryptography (DC) protocol. The DC protocol is based on the exchange of async states between a DC client (an application that wants to sign a PDF, XML, or Office document) and a DC server (an application that controls access to the private key). An async state can carry one or more signing requests, comprised of document hashes, or one or more signatures produced over those hashes.

In a typical scenario you get a client-side async state from the SignAsyncBegin method. This state contains document hashes to be signed on the DC server side. You then send the async state to the DC server (often represented by the DCAuth component), which processes it and produces a matching signature state. The async state produced by the server is then passed to the SignAsyncEnd method.

There are some conditions that should be met when signing PDF documents asynchronously. The advanced PDF signature levels, specifically BES, EPES, and LTV, require that the 'signingCertificate' attribute is included in the signature. This can only be satisfied if either ExternalCrypto is configured to use the asmdPKCS7 method, or the public copy of the signing certificate is provided on the pre-signing stage.

Please note that you will still be able to sign a document with the asmdPKCS1 method and no public copy of the certificate provided (resulting in the omission of the 'signingCertificate' attribute from the signature); however, most modern PDF processors will reject such signatures as invalid or non-compliant.

SignAsyncEnd Method (PDFSigner Component)

Completes the asynchronous signing operation.

Syntax

• C#
• VB.NET

public void SignAsyncEnd(string asyncReply);

Public Sub SignAsyncEnd(ByVal AsyncReply As String)

Remarks

When using the DC framework, call this method upon receiving the response state from the DC processor to complete the asynchronous signing process.

Before calling this method, assign the path to the pre-signed copy of the document obtained from the prior SignAsyncBegin call to InputFile (or InputStream). The method will embed the signature into the pre-signed document, and save the complete signed document to OutputFile (or OutputStream).

Note that depending on the signing method and DC configuration used, you may still need to provide the public part of the signing certificate via the SigningCertificate property.

Use the ExternalCrypto.AsyncDocumentID parameter to pass a specific document ID if using batched AsyncReply. If used, it should match the value provided on the pre-signing (SignAsyncBegin) stage.

AsyncState is a message of the distributed cryptography (DC) protocol. The DC protocol is based on the exchange of async states between a DC client (an application that wants to sign a PDF, XML, or Office document) and a DC server (an application that controls access to the private key). An async state can carry one or more signing requests, comprised of document hashes, or one or more signatures produced over those hashes.

In a typical scenario you get a client-side async state from the SignAsyncBegin method. This state contains document hashes to be signed on the DC server side. You then send the async state to the DC server (often represented by the DCAuth component), which processes it and produces a matching signature state. The async state produced by the server is then passed to the SignAsyncEnd method.

SignExternal Method (PDFSigner Component)

Signs the document using an external signing facility.

Syntax

• C#
• VB.NET

public void SignExternal();

Public Sub SignExternal()

Remarks

Use this method to create a PDF signature using an external signing facility for the cryptographic computations. SignExternal delegates the low-level signing operation to an external, remote, or custom signing engine. This method is useful if the signature has to be made by a device accessible through a custom or non-standard signing interface.

When all preparations are done and the hash is computed, the component fires the ExternalSign event which allows the hash value to be passed for signing.

Update Method (PDFSigner Component)

Updates a signature.

Syntax

• C#
• VB.NET

public void Update(int sigIndex);

Public Sub Update(ByVal SigIndex As Integer)

Remarks

PDF signatures may be updated from time to time by embedding newer/missing revocation information. The update approach is typically used to extend the validity of an LTV signature. Set SigIndex to the index of the signature field to update.

Updating is typically accompanied with a document timestamping operation. Set TimestampServer to have the component obtain and embed a document timestamp for you.

Before calling this method, provide the signed document via the InputFile (or InputStream) property. The updated document will be saved to OutputFile (or OutputStream).

ChainElementDownload Event (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnChainElementDownloadHandler OnChainElementDownload;

public delegate void OnChainElementDownloadHandler(object sender, PdfsignerChainElementDownloadEventArgs e);

public class PdfsignerChainElementDownloadEventArgs : EventArgs {
  public int Kind { get; }
  public string CertRDN { get; }
  public string CACertRDN { get; }
  public string Location { get; }
  public int Action { get; set; }
}

Public Event OnChainElementDownload As OnChainElementDownloadHandler

Public Delegate Sub OnChainElementDownloadHandler(sender As Object, e As PdfsignerChainElementDownloadEventArgs)

Public Class PdfsignerChainElementDownloadEventArgs Inherits EventArgs
  Public ReadOnly Property Kind As Integer
  Public ReadOnly Property CertRDN As String
  Public ReadOnly Property CACertRDN As String
  Public ReadOnly Property Location As String
  Public Property Action As Integer
End Class

Remarks

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

ChainElementNeeded Event (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnChainElementNeededHandler OnChainElementNeeded;

public delegate void OnChainElementNeededHandler(object sender, PdfsignerChainElementNeededEventArgs e);

public class PdfsignerChainElementNeededEventArgs : EventArgs {
  public int Kind { get; }
  public string CertRDN { get; }
  public string CACertRDN { get; }
}

Public Event OnChainElementNeeded As OnChainElementNeededHandler

Public Delegate Sub OnChainElementNeededHandler(sender As Object, e As PdfsignerChainElementNeededEventArgs)

Public Class PdfsignerChainElementNeededEventArgs Inherits EventArgs
  Public ReadOnly Property Kind As Integer
  Public ReadOnly Property CertRDN As String
  Public ReadOnly Property CACertRDN As String
End Class

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 (PDFSigner Component)

Reports the completion of a certificate chain validation.

Syntax

• C#
• VB.NET

public event OnChainValidatedHandler OnChainValidated;

public delegate void OnChainValidatedHandler(object sender, PdfsignerChainValidatedEventArgs e);

public class PdfsignerChainValidatedEventArgs : EventArgs {
  public int Index { get; }
  public string SubjectRDN { get; }
  public int ValidationResult { get; }
  public int ValidationDetails { get; }
}

Public Event OnChainValidated As OnChainValidatedHandler

Public Delegate Sub OnChainValidatedHandler(sender As Object, e As PdfsignerChainValidatedEventArgs)

Public Class PdfsignerChainValidatedEventArgs Inherits EventArgs
  Public ReadOnly Property Index As Integer
  Public ReadOnly Property SubjectRDN As String
  Public ReadOnly Property ValidationResult As Integer
  Public ReadOnly Property ValidationDetails As Integer
End Class

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.

ChainValidationProgress Event (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnChainValidationProgressHandler OnChainValidationProgress;

public delegate void OnChainValidationProgressHandler(object sender, PdfsignerChainValidationProgressEventArgs e);

public class PdfsignerChainValidationProgressEventArgs : EventArgs {
  public string EventKind { get; }
  public string CertRDN { get; }
  public string CACertRDN { get; }
  public int Action { get; set; }
}

Public Event OnChainValidationProgress As OnChainValidationProgressHandler

Public Delegate Sub OnChainValidationProgressHandler(sender As Object, e As PdfsignerChainValidationProgressEventArgs)

Public Class PdfsignerChainValidationProgressEventArgs Inherits EventArgs
  Public ReadOnly Property EventKind As String
  Public ReadOnly Property CertRDN As String
  Public ReadOnly Property CACertRDN As String
  Public Property Action As Integer
End Class

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 (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnDocumentLoadedHandler OnDocumentLoaded;

public delegate void OnDocumentLoadedHandler(object sender, PdfsignerDocumentLoadedEventArgs e);

public class PdfsignerDocumentLoadedEventArgs : EventArgs {
  public bool Cancel { get; set; }
}

Public Event OnDocumentLoaded As OnDocumentLoadedHandler

Public Delegate Sub OnDocumentLoadedHandler(sender As Object, e As PdfsignerDocumentLoadedEventArgs)

Public Class PdfsignerDocumentLoadedEventArgs Inherits EventArgs
  Public Property Cancel As Boolean
End Class

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 (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnEncryptedHandler OnEncrypted;

public delegate void OnEncryptedHandler(object sender, PdfsignerEncryptedEventArgs e);

public class PdfsignerEncryptedEventArgs : EventArgs {
  public bool CertUsed { get; }
  public string IssuerRDN { get; }
  public byte[] SerialNumber { get; }
  public byte[] SubjectKeyID { get; }
  public bool NeedCredential { get; }
  public bool SkipThis { get; set; }
}

Public Event OnEncrypted As OnEncryptedHandler

Public Delegate Sub OnEncryptedHandler(sender As Object, e As PdfsignerEncryptedEventArgs)

Public Class PdfsignerEncryptedEventArgs Inherits EventArgs
  Public ReadOnly Property CertUsed As Boolean
  Public ReadOnly Property IssuerRDN As String
  Public ReadOnly Property SerialNumber As Byte()
  Public ReadOnly Property SubjectKeyID As Byte()
  Public ReadOnly Property NeedCredential As Boolean
  Public Property SkipThis As Boolean
End Class

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 (PDFSigner Component)

Information about errors during signing/validation.

Syntax

• C#
• VB.NET

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, PdfsignerErrorEventArgs e);

public class PdfsignerErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As PdfsignerErrorEventArgs)

Public Class PdfsignerErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

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.

ExternalDecrypt Event (PDFSigner Component)

Handles remote or external decryption.

Syntax

• C#
• VB.NET

public event OnExternalDecryptHandler OnExternalDecrypt;

public delegate void OnExternalDecryptHandler(object sender, PdfsignerExternalDecryptEventArgs e);

public class PdfsignerExternalDecryptEventArgs : EventArgs {
  public string OperationId { get; }
  public string Algorithm { get; }
  public string Pars { get; }
  public string EncryptedData { get; }
  public string Data { get; set; }
}

Public Event OnExternalDecrypt As OnExternalDecryptHandler

Public Delegate Sub OnExternalDecryptHandler(sender As Object, e As PdfsignerExternalDecryptEventArgs)

Public Class PdfsignerExternalDecryptEventArgs Inherits EventArgs
  Public ReadOnly Property OperationId As String
  Public ReadOnly Property Algorithm As String
  Public ReadOnly Property Pars As String
  Public ReadOnly Property EncryptedData As String
  Public Property Data As String
End Class

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 component being used, and may be empty. Algorithm specifies the encryption algorithm being used, and Pars contains algorithm-dependent parameters.

The component 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

ExternalSign Event (PDFSigner Component)

Handles remote or external signing initiated by the SignExternal method or other source.

Syntax

• C#
• VB.NET

public event OnExternalSignHandler OnExternalSign;

public delegate void OnExternalSignHandler(object sender, PdfsignerExternalSignEventArgs e);

public class PdfsignerExternalSignEventArgs : EventArgs {
  public string OperationId { get; }
  public string HashAlgorithm { get; }
  public string Pars { get; }
  public string Data { get; }
  public string SignedData { get; set; }
}

Public Event OnExternalSign As OnExternalSignHandler

Public Delegate Sub OnExternalSignHandler(sender As Object, e As PdfsignerExternalSignEventArgs)

Public Class PdfsignerExternalSignEventArgs Inherits EventArgs
  Public ReadOnly Property OperationId As String
  Public ReadOnly Property HashAlgorithm As String
  Public ReadOnly Property Pars As String
  Public ReadOnly Property Data As String
  Public Property SignedData As String
End Class

Remarks

Assign a handler to this event if you need to delegate a low-level signing operation to an external, remote, or custom signing engine. Depending on the settings, the handler will receive a hashed or unhashed value to be signed.

The event handler must pass the value of Data to the signer, obtain the signature, and pass it back to the component via the SignedData parameter.

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

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

A sample MD5 hash encoded in base16: a0dee2a0382afbb09120ffa7ccd8a152 - lower case base16 A0DEE2A0382AFBB09120FFA7CCD8A152 - upper case base16

A sample event handler that uses the .NET RSACryptoServiceProvider class may look like the following: signer.OnExternalSign += (s, e) => { var cert = new X509Certificate2("cert.pfx", "", X509KeyStorageFlags.Exportable); var key = (RSACryptoServiceProvider)cert.PrivateKey; var dataToSign = e.Data.FromBase16String(); var signedData = key.SignHash(dataToSign, "2.16.840.1.101.3.4.2.1"); e.SignedData = signedData.ToBase16String(); };

Notification Event (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnNotificationHandler OnNotification;

public delegate void OnNotificationHandler(object sender, PdfsignerNotificationEventArgs e);

public class PdfsignerNotificationEventArgs : EventArgs {
  public string EventID { get; }
  public string EventParam { get; }
}

Public Event OnNotification As OnNotificationHandler

Public Delegate Sub OnNotificationHandler(sender As Object, e As PdfsignerNotificationEventArgs)

Public Class PdfsignerNotificationEventArgs Inherits EventArgs
  Public ReadOnly Property EventID As String
  Public ReadOnly Property EventParam As String
End Class

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:

PreRenderWidget Event (PDFSigner Component)

Fires when a signature widget is ready to be written to the document.

Syntax

• C#
• VB.NET

public event OnPreRenderWidgetHandler OnPreRenderWidget;

public delegate void OnPreRenderWidgetHandler(object sender, PdfsignerPreRenderWidgetEventArgs e);

public class PdfsignerPreRenderWidgetEventArgs : EventArgs {
  public bool AddAnother { get; set; }
  public bool ResetAnother { get; set; }
}

Public Event OnPreRenderWidget As OnPreRenderWidgetHandler

Public Delegate Sub OnPreRenderWidgetHandler(sender As Object, e As PdfsignerPreRenderWidgetEventArgs)

Public Class PdfsignerPreRenderWidgetEventArgs Inherits EventArgs
  Public Property AddAnother As Boolean
  Public Property ResetAnother As Boolean
End Class

Remarks

The component fires this event when it is ready to insert a new instance of the signature widget to the document. This event is fired repeatedly until the event handler sets the AddAnother parameter to false, allowing your application to create as many copies of the signature widget as required.

You can use this event handler to adjust the look of each widget copy. Set the ResetAnother parameter to true to automatically clean up all the existing widget settings after the current widget is saved. Setting ResetAnother to true will let you start every new widget from scratch. Keeping it set to false would result in every new widget looking the same as the previous one.

SignatureFound Event (PDFSigner Component)

Signifies the start of signature validation.

Syntax

• C#
• VB.NET

public event OnSignatureFoundHandler OnSignatureFound;

public delegate void OnSignatureFoundHandler(object sender, PdfsignerSignatureFoundEventArgs e);

public class PdfsignerSignatureFoundEventArgs : EventArgs {
  public int Index { get; }
  public string IssuerRDN { get; }
  public byte[] SerialNumber { get; }
  public byte[] SubjectKeyID { get; }
  public bool CertFound { get; }
  public bool ValidateSignature { get; set; }
  public bool ValidateChain { get; set; }
}

Public Event OnSignatureFound As OnSignatureFoundHandler

Public Delegate Sub OnSignatureFoundHandler(sender As Object, e As PdfsignerSignatureFoundEventArgs)

Public Class PdfsignerSignatureFoundEventArgs Inherits EventArgs
  Public ReadOnly Property Index As Integer
  Public ReadOnly Property IssuerRDN As String
  Public ReadOnly Property SerialNumber As Byte()
  Public ReadOnly Property SubjectKeyID As Byte()
  Public ReadOnly Property CertFound As Boolean
  Public Property ValidateSignature As Boolean
  Public Property ValidateChain As Boolean
End Class

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 (PDFSigner Component)

Marks the completion of the signature validation routine.

Syntax

• C#
• VB.NET

public event OnSignatureValidatedHandler OnSignatureValidated;

public delegate void OnSignatureValidatedHandler(object sender, PdfsignerSignatureValidatedEventArgs e);

public class PdfsignerSignatureValidatedEventArgs : EventArgs {
  public int Index { get; }
  public string IssuerRDN { get; }
  public byte[] SerialNumber { get; }
  public byte[] SubjectKeyID { get; }
  public int ValidationResult { get; }
}

Public Event OnSignatureValidated As OnSignatureValidatedHandler

Public Delegate Sub OnSignatureValidatedHandler(sender As Object, e As PdfsignerSignatureValidatedEventArgs)

Public Class PdfsignerSignatureValidatedEventArgs Inherits EventArgs
  Public ReadOnly Property Index As Integer
  Public ReadOnly Property IssuerRDN As String
  Public ReadOnly Property SerialNumber As Byte()
  Public ReadOnly Property SubjectKeyID As Byte()
  Public ReadOnly Property ValidationResult As Integer
End Class

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 (PDFSigner Component)

Signifies the start of a timestamp validation routine.

Syntax

• C#
• VB.NET

public event OnTimestampFoundHandler OnTimestampFound;

public delegate void OnTimestampFoundHandler(object sender, PdfsignerTimestampFoundEventArgs e);

public class PdfsignerTimestampFoundEventArgs : EventArgs {
  public int Index { get; }
  public string IssuerRDN { get; }
  public byte[] SerialNumber { get; }
  public byte[] SubjectKeyID { get; }
  public bool CertFound { get; }
  public bool ValidateTimestamp { get; set; }
  public bool ValidateChain { get; set; }
}

Public Event OnTimestampFound As OnTimestampFoundHandler

Public Delegate Sub OnTimestampFoundHandler(sender As Object, e As PdfsignerTimestampFoundEventArgs)

Public Class PdfsignerTimestampFoundEventArgs Inherits EventArgs
  Public ReadOnly Property Index As Integer
  Public ReadOnly Property IssuerRDN As String
  Public ReadOnly Property SerialNumber As Byte()
  Public ReadOnly Property SubjectKeyID As Byte()
  Public ReadOnly Property CertFound As Boolean
  Public Property ValidateTimestamp As Boolean
  Public Property ValidateChain As Boolean
End Class

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.

TimestampRequest Event (PDFSigner Component)

Fires when the component is ready to request a timestamp from an external TSA.

Syntax

• C#
• VB.NET

public event OnTimestampRequestHandler OnTimestampRequest;

public delegate void OnTimestampRequestHandler(object sender, PdfsignerTimestampRequestEventArgs e);

public class PdfsignerTimestampRequestEventArgs : EventArgs {
  public string TSA { get; }
  public string TimestampRequest { get; }
  public string TimestampResponse { get; set; }
  public bool SuppressDefault { get; set; }
}

Public Event OnTimestampRequest As OnTimestampRequestHandler

Public Delegate Sub OnTimestampRequestHandler(sender As Object, e As PdfsignerTimestampRequestEventArgs)

Public Class PdfsignerTimestampRequestEventArgs Inherits EventArgs
  Public ReadOnly Property TSA As String
  Public ReadOnly Property TimestampRequest As String
  Public Property TimestampResponse As String
  Public Property SuppressDefault As Boolean
End Class

Remarks

Subscribe to this event to intercept timestamp requests. You can use it to override timestamping requests and perform them in your code.

The TSA parameter indicates the timestamping service being used. It matches the value passed to the TimestampServer property. Set the SuppressDefault parameter to false if you would like to stop the built-in TSA request from going ahead. The built-in TSA request is also not performed if the returned TimestampResponse parameter is not empty.

TimestampValidated Event (PDFSigner Component)

Reports the completion of the timestamp validation routine.

Syntax

• C#
• VB.NET

public event OnTimestampValidatedHandler OnTimestampValidated;

public delegate void OnTimestampValidatedHandler(object sender, PdfsignerTimestampValidatedEventArgs e);

public class PdfsignerTimestampValidatedEventArgs : EventArgs {
  public int Index { get; }
  public string IssuerRDN { get; }
  public byte[] SerialNumber { get; }
  public byte[] SubjectKeyID { get; }
  public string Time { get; }
  public int ValidationResult { get; }
  public int ChainValidationResult { get; }
  public int ChainValidationDetails { get; }
}

Public Event OnTimestampValidated As OnTimestampValidatedHandler

Public Delegate Sub OnTimestampValidatedHandler(sender As Object, e As PdfsignerTimestampValidatedEventArgs)

Public Class PdfsignerTimestampValidatedEventArgs Inherits EventArgs
  Public ReadOnly Property Index As Integer
  Public ReadOnly Property IssuerRDN As String
  Public ReadOnly Property SerialNumber As Byte()
  Public ReadOnly Property SubjectKeyID As Byte()
  Public ReadOnly Property Time As String
  Public ReadOnly Property ValidationResult As Integer
  Public ReadOnly Property ChainValidationResult As Integer
  Public ReadOnly Property ChainValidationDetails As Integer
End Class

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 (PDFSigner Component)

Fires when a remote TLS party requests a client certificate.

Syntax

• C#
• VB.NET

public event OnTLSCertNeededHandler OnTLSCertNeeded;

public delegate void OnTLSCertNeededHandler(object sender, PdfsignerTLSCertNeededEventArgs e);

public class PdfsignerTLSCertNeededEventArgs : EventArgs {
  public string Host { get; }
  public string CANames { get; }
}

Public Event OnTLSCertNeeded As OnTLSCertNeededHandler

Public Delegate Sub OnTLSCertNeededHandler(sender As Object, e As PdfsignerTLSCertNeededEventArgs)

Public Class PdfsignerTLSCertNeededEventArgs Inherits EventArgs
  Public ReadOnly Property Host As String
  Public ReadOnly Property CANames As String
End Class

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 (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnTLSCertValidateHandler OnTLSCertValidate;

public delegate void OnTLSCertValidateHandler(object sender, PdfsignerTLSCertValidateEventArgs e);

public class PdfsignerTLSCertValidateEventArgs : EventArgs {
  public string ServerHost { get; }
  public string ServerIP { get; }
  public bool Accept { get; set; }
}

Public Event OnTLSCertValidate As OnTLSCertValidateHandler

Public Delegate Sub OnTLSCertValidateHandler(sender As Object, e As PdfsignerTLSCertValidateEventArgs)

Public Class PdfsignerTLSCertValidateEventArgs Inherits EventArgs
  Public ReadOnly Property ServerHost As String
  Public ReadOnly Property ServerIP As String
  Public Property Accept As Boolean
End Class

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 (PDFSigner Component)

Fires when a TLS handshake with Host successfully completes.

Syntax

• C#
• VB.NET

public event OnTLSEstablishedHandler OnTLSEstablished;

public delegate void OnTLSEstablishedHandler(object sender, PdfsignerTLSEstablishedEventArgs e);

public class PdfsignerTLSEstablishedEventArgs : EventArgs {
  public string Host { get; }
  public string Version { get; }
  public string Ciphersuite { get; }
  public byte[] ConnectionId { get; }
  public bool Abort { get; set; }
}

Public Event OnTLSEstablished As OnTLSEstablishedHandler

Public Delegate Sub OnTLSEstablishedHandler(sender As Object, e As PdfsignerTLSEstablishedEventArgs)

Public Class PdfsignerTLSEstablishedEventArgs Inherits EventArgs
  Public ReadOnly Property Host As String
  Public ReadOnly Property Version As String
  Public ReadOnly Property Ciphersuite As String
  Public ReadOnly Property ConnectionId As Byte()
  Public Property Abort As Boolean
End Class

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 (PDFSigner Component)

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

Syntax

• C#
• VB.NET

public event OnTLSHandshakeHandler OnTLSHandshake;

public delegate void OnTLSHandshakeHandler(object sender, PdfsignerTLSHandshakeEventArgs e);

public class PdfsignerTLSHandshakeEventArgs : EventArgs {
  public string Host { get; }
  public bool Abort { get; set; }
}

Public Event OnTLSHandshake As OnTLSHandshakeHandler

Public Delegate Sub OnTLSHandshakeHandler(sender As Object, e As PdfsignerTLSHandshakeEventArgs)

Public Class PdfsignerTLSHandshakeEventArgs Inherits EventArgs
  Public ReadOnly Property Host As String
  Public Property Abort As Boolean
End Class

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 (PDFSigner Component)

Reports the graceful closure of a TLS connection.

Syntax

• C#
• VB.NET

public event OnTLSShutdownHandler OnTLSShutdown;

public delegate void OnTLSShutdownHandler(object sender, PdfsignerTLSShutdownEventArgs e);

public class PdfsignerTLSShutdownEventArgs : EventArgs {
  public string Host { get; }
}

Public Event OnTLSShutdown As OnTLSShutdownHandler

Public Delegate Sub OnTLSShutdownHandler(sender As Object, e As PdfsignerTLSShutdownEventArgs)

Public Class PdfsignerTLSShutdownEventArgs Inherits EventArgs
  Public ReadOnly Property Host As String
End Class

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

Provides details of an individual X.509 certificate.

Remarks

This type provides access to X.509 certificate details.

Fields

Constructors

• C#
• VB.NET

public Certificate(byte[] bytes, int startIndex, int count, string password);

Public Certificate(ByVal Bytes As Byte(), ByVal StartIndex As Integer, ByVal Count As Integer, ByVal Password As String)

Loads the X.509 certificate from a memory buffer. Bytes is a buffer containing the raw certificate data. StartIndex and Count specify the starting position and number of bytes to be read from the buffer, respectively. Password is a password encrypting the certificate.

• C#
• VB.NET

public Certificate(byte[] certBytes, int certStartIndex, int certCount, byte[] keyBytes, int keyStartIndex, int keyCount, string password);

Public Certificate(ByVal CertBytes As Byte(), ByVal CertStartIndex As Integer, ByVal CertCount As Integer, ByVal KeyBytes As Byte(), ByVal KeyStartIndex As Integer, ByVal KeyCount As Integer, ByVal Password As String)

Loads the X.509 certificate from a memory buffer. CertBytes is a buffer containing the raw certificate data. CertStartIndex and CertCount specify the number of bytes to be read from the buffer, respectively. KeyBytes is a buffer containing the private key data. KeyStartIndex and KeyCount specify the starting position and number of bytes to be read from the buffer, respectively. Password is a password encrypting the certificate.

• C#
• VB.NET

public Certificate(byte[] bytes, int startIndex, int count);

Public Certificate(ByVal Bytes As Byte(), ByVal StartIndex As Integer, ByVal Count As Integer)

Loads the X.509 certificate from a memory buffer. Bytes is a buffer containing the raw certificate data. StartIndex and Count specify the starting position and number of bytes to be read from the buffer, respectively.

• C#
• VB.NET

public Certificate(string path, string password);

Public Certificate(ByVal Path As String, ByVal Password As String)

Loads the X.509 certificate from a file. Path specifies the full path to the file containing the certificate data. Password is a password encrypting the certificate.

• C#
• VB.NET

public Certificate(string certPath, string keyPath, string password);

Public Certificate(ByVal CertPath As String, ByVal KeyPath As String, ByVal Password As String)

Loads the X.509 certificate from a file. CertPath specifies the full path to the file containing the certificate data. KeyPath specifies the full path to the file containing the private key. Password is a password encrypting the certificate.

• C#
• VB.NET

public Certificate(string path);

Public Certificate(ByVal Path As String)

Loads the X.509 certificate from a file. Path specifies the full path to the file containing the certificate data.

• C#
• VB.NET

public Certificate(System.IO.Stream stream);

Public Certificate(ByVal Stream As System.IO.Stream)

Loads the X.509 certificate from a stream. Stream is a stream containing the certificate data.

• C#
• VB.NET

public Certificate(System.IO.Stream stream, string password);

Public Certificate(ByVal Stream As System.IO.Stream, ByVal Password As String)

Loads the X.509 certificate from a stream. Stream is a stream containing the certificate data. Password is a password encrypting the certificate.

• C#
• VB.NET

public Certificate(System.IO.Stream certStream, System.IO.Stream keyStream, string password);

Public Certificate(ByVal CertStream As System.IO.Stream, ByVal KeyStream As System.IO.Stream, ByVal Password As String)

Loads the X.509 certificate from a stream. CertStream is a stream containing the certificate data. KeyStream is a stream containing the private key. Password is a password encrypting the certificate.

• C#
• VB.NET

public Certificate();

Public Certificate()

Creates a new object with default field values.

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

• C#
• VB.NET

public CRL(byte[] bytes, int startIndex, int count);

Public CRL(ByVal Bytes As Byte(), ByVal StartIndex As Integer, ByVal Count As Integer)

Creates a CRL object from a memory buffer. Bytes is a buffer containing raw (DER) CRL data, StartIndex and Count specify the starting position and the length of the CRL data in the buffer, respectively.

• C#
• VB.NET

public CRL(string location);

Public CRL(ByVal Location As String)

Creates a CRL object by downloading it from a remote location.

• C#
• VB.NET

public CRL(System.IO.Stream stream);

Public CRL(ByVal Stream As System.IO.Stream)

Creates a CRL object from data contained in a stream.

• C#
• VB.NET

public CRL();

Public CRL()

Creates an empty CRL object.

ExternalCrypto Type

Specifies the parameters of external cryptographic calls.

Remarks

External cryptocalls are used in a Distributed Cryptography (DC) subsystem, which allows the delegation of security operations to the remote agent. For instance, it can be used to compute the signature value on the server, while retaining the client's private key locally.

Fields