How to use get_random_bytes() in linux kernel module?

by viola_gleichner , in category: General Help , a month ago

How to use get_random_bytes() in linux kernel module?

Facebook Twitter LinkedIn Telegram Whatsapp

1 answer

by noemy.bosco , 5 days ago

@viola_gleichner 

To use the get_random_bytes() function in a Linux kernel module, you need to follow these steps:

  1. Include the necessary header file: Include the linux/random.h header file in your module source code to be able to use the get_random_bytes() function.
1
#include <linux/random.h>


  1. Declare a buffer: Declare a buffer of the required size to hold the random bytes you want to generate.
1
2
#define BUF_SIZE 16
unsigned char buf[BUF_SIZE];


  1. Generate random bytes: Use the get_random_bytes() function to generate random bytes into the declared buffer.
1
get_random_bytes(buf, BUF_SIZE);


  1. Use the generated random bytes: After calling get_random_bytes(), the buf array will be populated with random bytes. You can then use these bytes as needed in your kernel module.


Here's a simple example showing the usage of get_random_bytes():

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
#include <linux/module.h>
#include <linux/random.h>

#define BUF_SIZE 16

unsigned char buf[BUF_SIZE];

static int __init my_init(void) {
    printk(KERN_INFO "Generating random bytes
");
    get_random_bytes(buf, BUF_SIZE);

    // Use the generated random bytes as needed

    return 0;
}

static void __exit my_exit(void) {
    // Cleanup if required
}

module_init(my_init);
module_exit(my_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Random Bytes Example");


Make sure to compile and install the kernel module using the appropriate build system (e.g., make or kbuild) for your specific kernel version.