-void arcfour_init(arcfour_ctx_t *c, uint8_t *key, uint8_t length);
-uint8_t arcfour_gen(arcfour_ctx_t *c);
+
+/** \fn void arcfour_init(arcfour_ctx_t *ctx, void *key, uint8_t length_B)
+ * \brief setup a context with a key
+ *
+ * This function sets up a ::arcfour_ctx_t context using
+ * the supplied key of the given length.
+ * \param ctx pointer to the context
+ * \param key pointer to the key
+ * \param length_B length of the key in bytes (between 1 and 255)
+ */
+
+void arcfour_init(const void *key, uint8_t length_B, arcfour_ctx_t *ctx);
+
+/** \fn uint8_t arcfour_gen(arcfour_ctx_t *ctx)
+ * \brief generates a byte of keystream
+ *
+ * This function generates the next byte of keystream
+ * from the supplied ::arcfour_ctx_t context which is updated accordingly
+ *
+ * \param ctx pointer to the context
+ * \return byte of keystream
+ */
+
+uint8_t arcfour_gen(arcfour_ctx_t *ctx);