Pdf C Reference Documentation

Pdf

Current Version: 9.5.0.88

A PDF class for various tasks such as signature verification, signing, encrypt, decrypt, etc.

Create/Dispose

HCkPdf instance = CkPdf_Create();
// ...
CkPdf_Dispose(instance);
HCkPdf CkPdf_Create(void);

Creates an instance of the HCkPdf object and returns a handle ("void *" pointer). The handle is passed in the 1st argument for the functions listed on this page.

void CkPdf_Dispose(HCkPdf handle);

Objects created by calling CkPdf_Create must be freed by calling this method. A memory leak occurs if a handle is not disposed by calling this function. Also, any handle returned by a Chilkat "C" function must also be freed by the application by calling the appropriate Dispose method, such as CkPdf_Dispose.

Callback Functions

Callback Functions introduced in Chilkat v9.5.0.56
void CkPdf_setAbortCheck(HCkPdf cHandle, BOOL (*fnAbortCheck)(void));

Provides the opportunity for a method call to be aborted. If TRUE is returned, the operation in progress is aborted. Return FALSE to allow the current method call to continue. This callback function is called periodically based on the value of the HeartbeatMs property. (If HeartbeatMs is 0, then no callbacks are made.) As an example, to make 5 AbortCheck callbacks per second, set the HeartbeatMs property equal to 200.

void CkPdf_setPercentDone(HCkPdf cHandle, BOOL (*fnPercentDone)(int pctDone));

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This callback is only called when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For methods that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

This callback counts as an AbortCheck callback, and takes the place of the AbortCheck event when it fires.

The return value indicates whether the method call should be aborted, or whether it should proceed. Return TRUE to abort, and FALSE to proceed.

void CkPdf_setProgressInfo(HCkPdf cHandle, void (*fnProgressInfo)(const char *name, const char *value));

This is a general callback that provides name/value information about what is happening at certain points during a method call. To see the information provided in ProgressInfo callbacks, if any, write code to handle this event and log the name/value pairs. Most are self-explanatory.

void CkPdf_setTaskCompleted(HCkPdf cHandle, void (*fnTaskCompleted)(HCkTask hTask));

Called in the background thread when an asynchronous task completes. (Note: When an async method is running, all callbacks are in the background thread.)

Properties

DebugLogFilePath
void CkPdf_getDebugLogFilePath(HCkPdf cHandle, HCkString retval);
void CkPdf_putDebugLogFilePath(HCkPdf cHandle, const char *newVal);
const char *CkPdf_debugLogFilePath(HCkPdf cHandle);

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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LastErrorHtml
void CkPdf_getLastErrorHtml(HCkPdf cHandle, HCkString retval);
const char *CkPdf_lastErrorHtml(HCkPdf cHandle);

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
void CkPdf_getLastErrorText(HCkPdf cHandle, HCkString retval);
const char *CkPdf_lastErrorText(HCkPdf cHandle);

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
void CkPdf_getLastErrorXml(HCkPdf cHandle, HCkString retval);
const char *CkPdf_lastErrorXml(HCkPdf cHandle);

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
BOOL CkPdf_getLastMethodSuccess(HCkPdf cHandle);
void CkPdf_putLastMethodSuccess(HCkPdf cHandle, BOOL newVal);
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of TRUE indicates success, a value of FALSE indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = TRUE and failure = FALSE.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to TRUE. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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NumPages
int CkPdf_getNumPages(HCkPdf cHandle);
Introduced in version 9.5.0.85

The number of pages in the currently open PDF.

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NumSignatures
int CkPdf_getNumSignatures(HCkPdf cHandle);
Introduced in version 9.5.0.85

The number of digital signatures present in the currently open PDF.

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UncommonOptions
void CkPdf_getUncommonOptions(HCkPdf cHandle, HCkString retval);
void CkPdf_putUncommonOptions(HCkPdf cHandle, const char *newVal);
const char *CkPdf_uncommonOptions(HCkPdf cHandle);
Introduced in version 9.5.0.85

This is a catch-all property to be used for uncommon needs. This property defaults to the empty string. Can be set to a list of the following comma separated keywords:

  • "WriteStandardXref" - When writing the PDF, write the cross reference section in standard format if possible. (The "standard format" is the older non-compressed format.)

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Utf8
BOOL CkPdf_getUtf8(HCkPdf cHandle);
void CkPdf_putUtf8(HCkPdf cHandle, BOOL newVal);

When set to TRUE, all "const char *" arguments are interpreted as utf-8 strings. If set to FALSE (the default), then "const char *" arguments are interpreted as ANSI strings. Also, when set to TRUE, and Chilkat method returning a "const char *" is returning the utf-8 representation. If set to FALSE, all "const char *" return values are ANSI strings.

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VerboseLogging
BOOL CkPdf_getVerboseLogging(HCkPdf cHandle);
void CkPdf_putVerboseLogging(HCkPdf cHandle, BOOL newVal);

If set to TRUE, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is FALSE. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
void CkPdf_getVersion(HCkPdf cHandle, HCkString retval);
const char *CkPdf_version(HCkPdf cHandle);

Version of the component/library, such as "9.5.0.63"

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Methods

AddSigningCert
BOOL CkPdf_AddSigningCert(HCkPdf cHandle, HCkCert cert);
Introduced in version 9.5.0.85

Adds a certificate to be used for PDF signing. To sign with more than one certificate, call AddSigningCert once per certificate.

Note: This method is used to provide the ability to sign once with multiple certificates. This is different than signing with one certificate, and then signing again with a different certificate.

Returns TRUE for success, FALSE for failure.

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GetDss
BOOL CkPdf_GetDss(HCkPdf cHandle, HCkJsonObject json);
Introduced in version 9.5.0.85

Gets the contents of the PDF's Document Security Store (/DSS) if it exists. Returns the information in JSON format (in json). If there is no /DSS then an empty JSON document "{}" is returned in json.

Returns TRUE for success, FALSE for failure.

More Information and Examples
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GetSignerCert
BOOL CkPdf_GetSignerCert(HCkPdf cHandle, int index, HCkCert cert);
Introduced in version 9.5.0.87

This method can be used to get the signer certificate after calling VerifySignature. The index should be the same value as the index passed to VerifySignature. If successful, and if the signer certificate is fully available within the signature, the cert is loaded with the signer certificate.

Returns TRUE for success, FALSE for failure.

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LastJsonData
HCkJsonObject CkPdf_LastJsonData(HCkPdf cHandle);
Introduced in version 9.5.0.88

Provides information about what transpired in the last method called. For many methods, there is no information. For some methods, details about what transpired can be obtained via LastJsonData. For example, after calling a method to verify a signature, the LastJsonData will return JSON with details about the algorithms used for signature verification.

Returns NULL on failure

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LoadBd
BOOL CkPdf_LoadBd(HCkPdf cHandle, HCkBinData pdfData);
Introduced in version 9.5.0.85

Loads the PDF file contained in pdfData.

Returns TRUE for success, FALSE for failure.

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LoadFile
BOOL CkPdf_LoadFile(HCkPdf cHandle, const char *filePath);
Introduced in version 9.5.0.85

Load a PDF file into this object in memory.

Returns TRUE for success, FALSE for failure.

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SetHttpObj
void CkPdf_SetHttpObj(HCkPdf cHandle, HCkHttp http);
Introduced in version 9.5.0.85

Sets the HTTP object to be used to communicate with the timestamp authority (TSA) server for cases where long term validation (LTV) of signatures is desired. The http is used to send the requests, and it allows for connection related settings and timeouts to be set. For example, if HTTP or SOCKS proxies are required, these features can be specified on the http.

The http is also used to send OCSP requests to store OCSP responses in the PDF's document security store (DSS).

Returns TRUE for success, FALSE for failure.

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SetSignatureJpeg
BOOL CkPdf_SetSignatureJpeg(HCkPdf cHandle, HCkBinData jpgData);
Introduced in version 9.5.0.85

Provides an optional JPG image to be included in the signature appearance. The JPG data is passed in jpgData.

Returns TRUE for success, FALSE for failure.

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SetSigningCert
BOOL CkPdf_SetSigningCert(HCkPdf cHandle, HCkCert cert);
Introduced in version 9.5.0.85

Specifies a certificate to be used when signing the PDF. Signing requires both a certificate and private key. In this case, the private key is implicitly specified if the certificate originated from a PFX that contains the corresponding private key, or if on a Windows-based computer where the certificate and corresponding private key are pre-installed.

Returns TRUE for success, FALSE for failure.

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SetSigningCert2
BOOL CkPdf_SetSigningCert2(HCkPdf cHandle, HCkCert cert, HCkPrivateKey privateKey);
Introduced in version 9.5.0.85

Specifies a digital certificate and private key to be used for signing the PDF.

Returns TRUE for success, FALSE for failure.

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SignPdf
BOOL CkPdf_SignPdf(HCkPdf cHandle, HCkJsonObject jsonOptions, const char *outFilePath);
Introduced in version 9.5.0.85

Signs the open PDF and if successful writes the signed PDF to the ARG3. The jsonOptions contains information and instructions about the signature.

Returns TRUE for success, FALSE for failure.

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SignPdfAsync (1)
HCkTask CkPdf_SignPdfAsync(HCkPdf cHandle, HCkJsonObject jsonOptions, const char *outFilePath);
Introduced in version 9.5.0.85

Creates an asynchronous task to call the SignPdf method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns NULL on failure

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VerifySignature
BOOL CkPdf_VerifySignature(HCkPdf cHandle, int index, HCkJsonObject sigInfo);
Introduced in version 9.5.0.85

Verifies the Nth signature contained in the PDF, where the 1st signature is indicated by an index of 0. Returns TRUE if the signature valid, otherwise returns FALSE. The sigInfo is an output argument and is populated with information about the validated or unvalidated signature.

Returns TRUE for success, FALSE for failure.

More Information and Examples
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