sasl_auth.c

#include <stdlib.h>

/* Stubs to make this compile */

typedef struct CassCluster_ {
} CassCluster;

typedef enum CassError_ {
  CASS_OK = 0
} CassError;

/* Proposed external SASL interface for the DataStax C/C++ driver */

typedef enum CassAuthState_ {
  CASS_AUTH_STATE_INIT,
  CASS_AUTH_STATE_CHALLENGE,
  CASS_AUTH_STATE_SUCCESS
} CassAuthState;

typedef struct CassAuth_ {
  CassAuthState state;

  char* response;
  const size_t response_capacity;

  const char* challenge_or_token;
  const size_t challege_or_token_size;
} CassAuth;

/*
 * Callback for interfacing with SASL authentication.
 *
 * Return -1 if an error occurred otherwise return the size written into the
 * response buffer. If the response is bigger than 'response_capacity' then
 * return the required size. If the returned size is greater than
 * 'response_capacity' then the callback will be recalled with a response
 * buffer equal to previously returned size. 0 should be returned for a
 * call where 'state' is CASS_AUTH_STATE_SUCCESS;
 */
typedef ssize_t (*CassAuthCallback)(CassAuth* auth, void* data);


CassError
cass_cluster_set_auth_callback(CassCluster* cluster,
                               CassAuthCallback callback,
                               void* data);

/* Example usage */

ssize_t on_auth(CassAuth* auth, void* data) {
  size_t required_capcity = 1024;

  switch (auth->state) {
    case CASS_AUTH_STATE_INIT:
      /* Check to see if reponse buffer is big enough */
      if (auth->response_capacity < required_capcity) {
        return required_capcity;
      }

      /* Write into response buffer */

      return required_capacity;

    case CASS_AUTH_STATE_CHALLENGE:
      /* Check to see if reponse buffer is big enough */
      if (auth->response_capacity < required_capcity) {
        return required_capcity;
      }

      /* Verify challenge */

      /* Write into response buffer */

      return required_capacity;

    case CASS_AUTH_STATE_SUCCESS:

      /* Use token */

      return 0;
  }
}

int main() {
  CassCluster* cluster = NULL; /* Create cluster */
  void* some_sasl_object = NULL;  /* Initialize SASL object */

  cass_cluster_set_auth_callback(cluster, on_auth, some_sasl_object);

  return 0;
}