libspf2 | Sender Policy Framework for SMTP authorization | Authorization library

libspf2 is a C library typically used in Security, Authorization applications. libspf2 has no bugs, it has no vulnerabilities and it has low support. You can download it from GitHub.

An example client implementation is in spf_example.c with a little more error checking. The basic cases are as follows:. The SPF server is reusable, and thread-safe. It must be freed using SPF_server_free. @code SPF_server_t *spf_server = SPF_server_new(SPF_DNS_CACHE, 0); @endcode. Create a request, and set the relevant fields in it. Each setter method returns an SPF_errcode_t, which will inform you of error conditions, such as out-of-memory or invalid argument. @code SPF_request_t *spf_request = SPF_request_new(spf_server); SPF_request_set_ipv4_str(spf_request, "123.45.6.7"); SPF_request_set_env_from(spf_request, "clientdomain.com"); @endcode. Now that we have built a query, we may execute it. It will use the SPF_server_t which was passed to the query constructor. As usual, the SPF_request_query_mailfrom method returns an error code, although much richer errors are returned inside the SPF_response_t - see spf_response.h for more details of that API. @code SPF_response_t *spf_response = NULL; SPF_request_query_mailfrom(spf_request, &spf_response); printf("Result is %s\n", SPF_strresult(SPF_response_result(spf_response))); @endcode. When we have finished with the response, we must free it and the request. @code SPF_response_free(spf_response); SPF_request_free(spf_request); @endcode. We can execute many requests in parallel threads on the same server, but before the program exits, we must free the server.