I am trying to invoke the SHA-1 algorithm using the Linux kernel driver. And the code that I am referring to has used the header file linux/crypto.h. The code uses a struct hash_desc desc; structure in the code which I thought was declared in the header file crypto.h. However when I looked for it, it was never initialized.
#include <linux/module.h>
#include <linux/crypto.h> /* for sha1 */
#include <linux/scatterlist.h> /* for sha1 */
struct scatterlist *sg;
struct crypto_hash *tfm;
struct hash_desc desc;
void *ptr;
In the above code block, when compilation, it only throws an error at hash_desc but I checked and crypto_hash was also not declared or initialized in any of the header files yet there is no error in that line. The error I am getting is that storage size of "desc" isn't known. I tried declaring it in the header file crypto.h. Here is what I added in the header file,
struct hash_desc desc;
u32 flags;
I don't really know what this is but this is what read through various sources. I thought that u32 will declare the size for the struct but that was not the case and it is still showing the same error, but now in both the code and the header files.