Foxit PDF SDK
fsdk.SignatureCallback Class Reference

Public Member Functions

def CheckCertificateValidity (cert_path, cert_password, client_data)
 A callback function used to check the validity of a certificate.
More...
 
def ContinueCalcDigest (client_data, pause)
 A callback function used to continue the custom digest calculation process.
More...
 
def GetDigest (client_data)
 A callback function used to get the digest after the calculation process is finished.
More...
 
def IsNeedPadData ()
 A callback function used to check whether to return all contents with padding zero or not, when callback function fsdk.SignatureCallback.VerifySigState is called.
More...
 
def Release ()
 A callback function used to release current callback object itself.
More...
 
def Sign (digest, digest_length, cert_file_stream, cert_password, digest_algorithm, client_data)
 A callback function used to do signing and return the signed data.
More...
 
def Sign (digest, digest_length, cert_path, cert_password, digest_algorithm, client_data)
 A callback function used to do signing and return the signed data.
More...
 
def VerifySigState (digest, digest_length, signed_data, signed_data_len, client_data)
 A callback function used to verify the integrity of a signature and return the verify state.
More...
 

Detailed Description

This class represent a callback object to sign or verify signature. All the pure virtual functions in this class are used as callback functions and should be implemented by user, in order to sign or verify signature in a customized way.
User can set register customized signature callback object to Foxit PDF SDK by function fsdk.LibraryRegisterSignatureCallback with filter and sub filter as the callback name.

See also
fsdk.Library

Member Function Documentation

◆ CheckCertificateValidity()

def fsdk.SignatureCallback.CheckCertificateValidity (   cert_path,
  cert_password,
  client_data 
)

A callback function used to check the validity of a certificate.

This callback function will be triggered when function fsdk.Signature.StartSign is called. If no need to check the certificate, value fsdk.SignatureCallbackE_CertValid can be returned directly.

Parameters
[in]cert_pathA full path of a certificate file (including file name and extension), which will be used for signing. This is passed by user from function fsdk.Signature.StartSign .
[in]cert_passwordA password string used to open the cert file. If this is an empty string, that means no password is required.This is passed by user from function fsdk.Signature.StartSign .
[in]client_dataA user-defined object, which is passed by user from function fsdk.Signature.StartSign .
Returns
Certificate validity. Please refer to values starting from fsdk.SignatureCallbackE_CertValid and it should be one of these values.

◆ ContinueCalcDigest()

def fsdk.SignatureCallback.ContinueCalcDigest (   client_data,
  pause 
)

A callback function used to continue the custom digest calculation process.

Parameters
[in]pausePause object which decides if the calculation process needs to be paused. If this is null, it means not to pause during the calculation process. If this is not null, please check the the return value of function NeedToPauseNow() of this input parameter and decide when to pause the calculation process.
[in]client_dataA user-defined object, which is passed by user from function fsdk.Signature.StartSign or fsdk.Signature.StartVerify .
Returns
fsdk.ProgressiveE_Finished means the calculation process has finished successfully.
fsdk.ProgressiveE_ToBeContinued means the calculation process is not finished yet and callback function fsdk.SignatureCallback.ContinueCalcDigest would be triggered again to continue the process.
fsdk.ProgressiveE_Error means any error occurs.

◆ GetDigest()

def fsdk.SignatureCallback.GetDigest (   client_data)

A callback function used to get the digest after the calculation process is finished.

This callback function will be triggered when the calculation process is finished successfully.

Parameters
[in]client_dataA user-defined object, which is passed by user from function fsdk.Signature.StartSign or fsdk.Signature.StartVerify .
Returns
The digest string. If there is any error, please return an empty string.

◆ IsNeedPadData()

def fsdk.SignatureCallback.IsNeedPadData ( )

A callback function used to check whether to return all contents with padding zero or not, when callback function fsdk.SignatureCallback.VerifySigState is called.

Returns
true means to return all data in contents steam (including padding zero), while false means to return contents data without padding zero in stream end.

◆ Release()

def fsdk.SignatureCallback.Release ( )

A callback function used to release current callback object itself.

Returns
None.

◆ Sign() [1/2]

def fsdk.SignatureCallback.Sign (   digest,
  digest_length,
  cert_file_stream,
  cert_password,
  digest_algorithm,
  client_data 
)

A callback function used to do signing and return the signed data.

Host application provides this callback function for custom sign mechanism. This callback function would be triggered during the signature signing process.

Parameters
[in]digestThe digest data buffer, for source file buffer to be signed.
[in]digest_lengthThe size of digest data buffer.
[in]cert_file_streamA fsdk.StreamCallback object which is implemented by user to access content of a certificate file which will be used for signing.
[in]cert_passwordThe password string, used to open the cert file. If this is an empty string, that means no password is required.
[in]digest_algorithmThe algorithm of message digest for signed data. Please refer to values starting from fsdk.SignatureE_DigestSHA1 and this would be one of these values.
[in]client_dataA user-defined object, which is passed by user from function fsdk.Signature.StartSign or fsdk.Signature.StartVerify .
Returns
Signed data. If there is any error, please return an empty string.
The length of returned signed data should be within the default length of signature contents which is 7942 by default or specified by fucntion fsdk.Signature.SetDefaultContentsLength before signing the unsigned signature.

◆ Sign() [2/2]

def fsdk.SignatureCallback.Sign (   digest,
  digest_length,
  cert_path,
  cert_password,
  digest_algorithm,
  client_data 
)

A callback function used to do signing and return the signed data.

Host application provides this callback function for custom sign mechanism. This callback function would be triggered during the signature signing process.

Parameters
[in]digestThe digest data buffer, for source file buffer to be signed.
[in]digest_lengthThe size of digest data buffer.
[in]cert_pathThe certificate file path, which will be used for signing.
[in]cert_passwordThe password string, used to open the cert file. If this is an empty string, that means no password is required.
[in]digest_algorithmThe algorithm of message digest for signed data. Please refer to values starting from fsdk.SignatureE_DigestSHA1 and this would be one of these values.
[in]client_dataA user-defined object, which is passed by user from function fsdk.Signature.StartSign or fsdk.Signature.StartVerify .
Returns
Signed data. If there is any error, please return an empty string.
The length of returned signed data should be within the default length of signature contents which is 7942 by default or specified by fucntion fsdk.Signature.SetDefaultContentsLength before signing the unsigned signature.

◆ VerifySigState()

def fsdk.SignatureCallback.VerifySigState (   digest,
  digest_length,
  signed_data,
  signed_data_len,
  client_data 
)

A callback function used to verify the integrity of a signature and return the verify state.

Host application provides this callback function for custom sign mechanism. This callback function would be triggered during the signature verifying process.
From 7.0, this callback function is only used to verify the intergrity of a signature. Please check the comment about return value for more details.

Parameters
[in]digestThe digest data buffer, for source file buffer to be verified.
[in]digest_lengthThe size of digest data buffer.
[in]signed_dataThe signed data buffer.
[in]signed_data_lenThe size of signed data buffer.
[in]client_dataA user-defined object, which is passed by user from function fsdk.Signature.StartSign or fsdk.Signature.StartVerify .
Returns
Verify state: