certmanager/lib

CryptPlug::StructuringInfo Struct Reference
[Signing and Encrypting Actions]

#include <cryptplug.h>

List of all members.


Detailed Description

Information record returned by signing and by encrypting functions - this record should be used together with a corresponding free_StructuringInfo() function call.

Use this information to compose a MIME object containing signed and/or encrypted content (or to build a text frame around your flat non-MIME message body, resp.)

If value returned in makeMimeObject is TRUE the text strings returned in contentTypeMain and contentDispMain and contentTEncMain (and, if required, content[..]Version and bodyTextVersion and content[..]Sig) should be used to compose a respective MIME object.
If FALSE the texts returned in flatTextPrefix and flatTextSeparator and flatTextPostfix are to be used instead.
Allways either the content[..] and bodyTextVersion parameters or the flatText[..] parameters are holding valid data - never both of them may be used simultaneously as plugins will just ignore the parameters not matching their makeMimeObject setting.

When creating your MIME object please observe these common rules:

  • Parameters named contentType[..] and contentDisp[..] and contentTEnc[..] will return the values for the respective MIME headers 'Content-Type' and 'Content-Disposition' and 'Content-Transfer-Encoding'. The following applies to these parameters:
  • The relevant MIME part may only be created if the respective contentType[..] parameter is holding a non-zero-length string. If the contentType[..] parameter value is invalid or holding an empty string the respective contentDisp[..] and contentTEnc[..] parameters should be ignored.
  • If the respective contentDisp[..] or contentTEnc[..] parameter is NULL or holding a zero-length string it is up to you whether you want to add the relevant MIME header yourself, but since it in in the responsibility of the plugin implementors to provide you with all neccessary 'Content-[..]' header information you should not need to define them if they are not returned by the signing or encrypting function - otherwise this may be considered as a bug in the plugin and you could report the missing MIME header information to the address returned by the bugURL() function.
If makeMultiMime returns FALSE the contentTypeMain returned must not be altered but used to specify a single part mime object holding the code bloc, e.g. this is used for 'enveloped-data' single part MIME objects. In this case you should ignore both the content[..]Version and content[..]Code parameters.

If makeMultiMime returns TRUE also the following rules apply:

  • If includeCleartext is TRUE you should include the cleartext as first part of our multipart MIME object, typically this is TRUE when signing mails but FALSE when encrypting.
  • The contentTypeMain returned typically starts with "multipart/" while providing a "protocol" and a "micalg" parameter: just add an appropriate "; boundary=[your \c boundary \c string]" to get the complete Content-Type value to be used for the MIME object embedding both the signed part and the signature part (or - in case of encrypting - the version part and the code part, resp.).
  • If contentTypeVersion is holding a non-zero-length string an additional MIME part must added immediately before the code part, this version part's MIME headers must have the unaltered values of contentTypeVersion and (if they are holding non-zero-length strings) contentDispVersion and contentTEncVersion, the unaltered contents of bodyTextVersion must be it's body.
  • The value returned in contentTypeCode is specifying the complete Content-Type to be used for this multipart MIME object's signature part (or - in case of encrypting - for the code part following after the version part, resp.), you should not add/change/remove anything here but just use it's unaltered value for specifying the Content-Type header of the respective MIME part.
  • The same applies to the contentDispCode value: just use it's unaltered value to specify the Content-Disposition header entry of the respective MIME part.
  • The same applies to the contentTEncCode value: just use it's unaltered value to specify the Content-Transfer-Encoding header of the respective MIME part.
If value returned in makeMimeObject is FALSE the text strings returned in flatTextPrefix and flatTextPostfix should be used to build a frame around the cleartext and the code bloc holding the signature (or - in case of encrypting - the encoded data bloc, resp.).
If includeCleartext is TRUE this frame should also include the cleartext as first bloc, this bloc should be divided from the code bloc by the contents of flatTextSeparator - typically this is used for signing but not when encrypting.
If includeCleartext is FALSE you should ignore both the cleartext and the flatTextSeparator parameter.

How to use StructuringInfo data in your program:

  • To compose a signed message please act as described below.
  • For constructing an encrypted message just replace the signMessage() call by the respective encryptMessage() call and then proceed exactly the same way.
  • In any case make sure to free your ciphertext and to call free_StructuringInfo() when you are done with processing the data returned by the signing (or encrypting, resp.) function.

    char* ciphertext;
    StructuringInfo structInf;

    if( ! signMessage( cleartext, &ciphertext, certificate,
                       &structuring ) ) {

        myErrorDialog( "Error: could not sign the message!" );

    } else {
      if( structInf.makeMimeObject ) {

        // Build the main MIME object.
        // This is done by
        // using the header values returned in
        // structInf.contentTypeMain and in
        // structInf.contentDispMain and in
        // structInf.contentTEncMain.
        ..

        if( ! structInf.makeMultiMime ) {

          // Build the main MIME object's body.
          // This is done by
          // using the code bloc returned in
          // ciphertext.
          ..

        } else {

          // Build the encapsulated MIME parts.
          if( structInf.includeCleartext ) {

            // Build a MIME part holding the cleartext.
            // This is done by
            // using the original cleartext's headers and by
            // taking it's original body text.
            ..

          }
          if(    structInf.contentTypeVersion
              && 0 < strlen( structInf.contentTypeVersion ) ) {

            // Build a MIME part holding the version information.
            // This is done by
            // using the header values returned in
            // structInf.contentTypeVersion and
            // structInf.contentDispVersion and
            // structInf.contentTEncVersion and by
            // taking the body contents returned in
            // structInf.bodyTextVersion.
            ..

          }
          if(    structInf.contentTypeCode
              && 0 < strlen( structInf.contentTypeCode ) ) {

            // Build a MIME part holding the code information.
            // This is done by
            // using the header values returned in
            // structInf.contentTypeCode and
            // structInf.contentDispCode and
            // structInf.contentTEncCode and by
            // taking the body contents returned in
            // ciphertext.
            ..

          } else {

            // Plugin error!
            myErrorDialog( "Error: Cryptography plugin returned a main"
                           "Content-Type=Multipart/.. but did not "
                           "specify the code bloc's Content-Type header."
                           "\nYou may report this bug:"
                           "\n" + cryptplug.bugURL() );
          }
        }
      } else  {

        // Build a plain message body
        // based on the values returned in structInf.
        // Note: We do _not_ insert line breaks between the parts since
        //       it is the plugin job to provide us with ready-to-use
        //       texts containing all neccessary line breaks.
        strcpy( myMessageBody, structInf.plainTextPrefix );
        if( structInf.includeCleartext ) {
          strcat( myMessageBody, cleartext );
          strcat( myMessageBody, structInf.plainTextSeparator );
        }
        strcat( myMessageBody, *ciphertext );
        strcat( myMessageBody, structInf.plainTextPostfix );
      }

      // free the memory that was allocated
      // for the ciphertext
      free( ciphertext );

      // free the memory that was allocated
      // for our StructuringInfo's char* members
      free_StructuringInfo( &structuring );
    }

Note:
Make sure to call free_StructuringInfo() when you are done with processing the StructuringInfo data!
See also:
free_StructuringInfo

signMessage, encryptMessage, encryptAndSignMessage

Definition at line 622 of file cryptplug.h.


Public Attributes

bool includeCleartext
bool makeMimeObject
bool makeMultiMime
char * contentTypeMain
char * contentDispMain
char * contentTEncMain
char * contentTypeVersion
char * contentDispVersion
char * contentTEncVersion
char * bodyTextVersion
char * contentTypeCode
char * contentDispCode
char * contentTEncCode
char * flatTextPrefix
char * flatTextSeparator
char * flatTextPostfix

Member Data Documentation

specifies whether we should include the cleartext as first part of our multipart MIME object (or - for non-MIME messages - as flat text to be set before the ciphertext, resp.), typically this is TRUE when signing mails but FALSE when encrypting
(this parameter is relevant no matter whether makeMimeObject is TRUE or FALSE)

Definition at line 623 of file cryptplug.h.

specifies whether we should create a MIME object or a flat text message body

Definition at line 633 of file cryptplug.h.

specifies whether we should create a 'Multipart' MIME object or a single part object, if FALSE only contentTypeMain, contentDispMain and contentTEncMain may be used and all other parameters have to be ignored
(ignore this parameter if makeMimeObject is FALSE)

Definition at line 636 of file cryptplug.h.

value of the main 'Content-Type' header
(ignore this parameter if makeMimeObject is FALSE)

Definition at line 644 of file cryptplug.h.

value of the main 'Content-Disposition' header
(ignore this parameter if makeMimeObject is FALSE)

Definition at line 648 of file cryptplug.h.

value of the main 'Content-TransferEncoding' header
(ignore this parameter if makeMimeObject is FALSE)

Definition at line 652 of file cryptplug.h.

'Content-Type' of the additional version part that might preceed the code part - if NULL or zero length no version part must be created
(ignore this parameter if either makeMimeObject or makeMultiMime is FALSE)

Definition at line 656 of file cryptplug.h.

'Content-Disposition' of the additional preceeding the code part (only valid if contentTypeVersion holds a non-zero-length string)
(ignore this parameter if either makeMimeObject or makeMultiMime is FALSE or if contentTypeVersion does not return a non-zero-length string)

Definition at line 663 of file cryptplug.h.

'Content-Transfer-Encoding' of the additional version part (only valid if contentTypeVersion holds a non-zero-length string)
(ignore this parameter if either makeMimeObject or makeMultiMime is FALSE or if contentTypeVersion does not return a non-zero-length string)

Definition at line 671 of file cryptplug.h.

body text of the additional version part (only valid if contentTypeVersion holds a non-zero-length string)
(ignore this parameter if either makeMimeObject or makeMultiMime is FALSE or if contentTypeVersion does not return a non-zero-length string)

Definition at line 679 of file cryptplug.h.

'Content-Type' of the code part holding the signature code (or the encrypted data, resp.)
(ignore this parameter if either makeMimeObject or makeMultiMime is FALSE)

Definition at line 686 of file cryptplug.h.

'Content-Disposition' of the code part
(ignore this parameter if either makeMimeObject or makeMultiMime is FALSE or if contentTypeCode does not return a non-zero-length string)

Definition at line 692 of file cryptplug.h.

'Content-Type' of the code part
(ignore this parameter if either makeMimeObject or makeMultiMime is FALSE or if contentTypeCode does not return a non-zero-length string)

Definition at line 697 of file cryptplug.h.

text to preceed the main text (or the code bloc containing the encrypted main text, resp.)
(ignore this parameter if makeMimeObject is TRUE)

Definition at line 703 of file cryptplug.h.

text to be put between the main text and the signature code bloc (not used when encrypting)
(ignore this parameter if makeMimeObject is TRUE or if includeCleartext is FALSE)

Definition at line 708 of file cryptplug.h.

text to follow the signature code bloc (or the encrypted data bloc, resp.)
(ignore this parameter if makeMimeObject is TRUE)

Definition at line 714 of file cryptplug.h.


The documentation for this struct was generated from the following file:
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