Overview

1. lib = dk_init();
   • initialize an instance of the library
   • this must be done once before any of the other calls are made
   • this needs to be called once when the application is started, but its result can be reused at the start of processing of each message
   • the remaining steps can use the same value of lib, even in multiple threads and over multiple messages
2. dk = dk_sign(lib, ...);
   • initialize a handle set up for signing the message
   • at this point a canonicalization, signing algorithm and secret key are selected by the caller
3. stat = dk_header(dk, ...);
   • pass a header to libdk
   • this should be done once for each header that should be included in computation of the signature (currently all of them)
4. stat = dk_eoh(dk);
   • notify libdk that the end of this message's headers has been reached
5. stat = dk_body(dk, ...);
   • pass to libdk a chunk of the body that should be included in computation of the signature (currently all of it)
   • repeat for each body chunk that arrives
6. stat = dk_eom(dk, ...);
   • notify libdk that the end of this message has been reached
   • get back any informational flags of interest from libdk
7. stat = dk_getsig(dk, ...);
   • compute the base64-encoded signature for the message
   • the signing algorithm was selected in the call to dk_sign() above
   • the data returned here coupled with the parameters to the dk_sign() call make up the content of the signature that needs to be prepended to the message according to the DomainKeys specification
8. stat = dk_free(dk);
   • free resources related to this message
9. stat = dk_close(dk);
   • free resources related to this library instance

1. lib = dk_init();
   • initialize an instance of the library
   • this must be done once before any of the other calls are made
   • this needs to be called once when the application is started, but its result can be reused at the start of processing of each message
   • the remaining steps can use the same value of lib, even in multiple threads and over multiple messages
2. dk = dk_verify(lib, ...);
   • initialize a handle set up for verifying the message
   • the canonicalization and signing algorithms and public key were selected by the agent that signed the message, and so don't need to be provided here
3. stat = dk_header(dk, ...);
   • pass a header to libdk
   • this should be done once for each header that should be included in computation of the digest to be verified (currently all of them)
4. stat = dk_eoh(dk);
   • notify libdk that the end of this message's headers has been reached
5. stat = dk_body(dk, ...);
   • pass to libdk a chunk of the body that should be included in computation of the digest to be verified (currently all of it)
6. stat = dk_eom(dk, ...);
   • notify libdk that the end of this message has been reached
   • get back any informational flags of interest from libdk
   • see if stat is DK_STAT_OK (verification OK) or DK_STAT_BADSIG (verification failed)
7. stat = dk_free(dk);
   • free resources related to this message
8. stat = dk_close(dk);
   • free resources related to this library instance