DynaPDF Manual - Page 224
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Function Reference
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However, incremental updates are not supported by DynaPDF that is the reason why only empty
signature fields are imported. Because DynaPDF creates always a completely new PDF file, it makes
no sense to import existing signatures, they would become invalid.
Possible function errors
When trying to sign a PDF file the function must first parse the certificate file before a signature can
be created. This process can fail, due to an invalid file path or due to an unsupported certificate file
format that was passed to the function. The PDF file will only be closed and signed if the certificate
file was valid and if no other error occurred during the parsing process.
If an error occurred due to an invalid certificate file, invalid file path and so on, the function returns
zero and passes an error message to the error callback function if any. All errors during the parsing
process of the certificate file are non-fatal so that the PDF file is still in memory when the function
returns. It is then possible to change the certificate file and trying to sign the PDF file again.
To determine whether the PDF was already deleted or of it is still in memory use the function
HaveOpenDoc(). The function returns true if the PDF file is still in memory. If the function returns
false, the last error was fatal and the PDF file has already been deleted.
The buffer of a memory based PDF file can be returned by GetBuffer() after this function was called.
Note that GetBuffer() does not free the used resources because it returns a pointer to the original
buffer. After the buffer was processed by your application call FreePDF() to free the uses resources.
See also CreateNewPDF(), GetBuffer(), FreePDF().
Remarks:
Further information about digital signatures can be found under Digital Signatures. To encrypt and
sign a PDF file use the function CloseAndSingFileEx(). The appearance of a signature field can be
user defined. See CreateSigFieldAP() for further information.
Return values:
If the function succeeds the return value is 1. If the function fails the return value is 0.
CloseAndSignFileEx
Syntax:
SI32 pdfCloseAndSignFileEx(
const PPDF* IPDF,
// Instance pointer
const char* OpenPwd,
// Optional Open password
const char* OwnerPwd,
// Optional Owner password
TKeyLen KeyLen,
// Key length (40 or 128 bit)
TRestrictions Restrict, // Restrictions
const char* CertFile,
// File path to a PKCS#12 certificate file
const char* Password,
// Password to decrypt the cert's private key
const char* Reason,
// Optional reason string
const char* Location)
// Optional signers location string
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