wolfssl-examples/kernel/bsdkm

FreeBSD wolfcrypt kernel module example

About

Tested on FreeBSD 14.2:

uname -rsm
FreeBSD 14.2-RELEASE amd64

Build libwolfssl.ko

cd ~/
git clone https://github.com/wolfSSL/wolfssl.git
cd ~/wolfssl
./autogen.sh
./configure --enable-freebsdkm --enable-cryptonly --enable-crypttests --enable-all-crypto && make
file bsdkm/libwolfssl.ko

Load the kernel module:

sudo kldload bsdkm/libwolfssl.ko

In dmesg output you should see something like:

dmesg | tail -n10
PKCS7enveloped  test passed!
PKCS7authenveloped  test passed!
mp       test passed!
prime    test passed!
logging  test passed!
mutex    test passed!
crypto callback test passed!
Test complete
wolfCrypt self-test passed.
info: wolfkmod init good

and kldstat:

kldstat
Id Refs Address                Size Name
 1   20 0xffffffff80200000  1f3c6c0 kernel
 2    1 0xffffffff82818000     3220 intpm.ko
 3    1 0xffffffff8281c000     2178 smbus.ko
 4    1 0xffffffff8281f000     430c virtio_console.ko
 5    1 0xffffffff82824000     3360 uhid.ko
 6    1 0xffffffff82828000     3360 wmt.ko
17    1 0xffffffff8282c000   154520 libwolfssl.ko

wolfssl will also appear in vmstat entries:

vmstat -m | grep wolf
         wolfssl    0     0 1275500 16,32,64,128,256,384,512,1024,2048,4096,8192,16384

Build this example

From this example dir:

make && file bsd_example.ko

Load it:

sudo kldload ./bsd_example.ko

dmesg should show:

dmesg | tail -n5
Test complete
wolfCrypt self-test passed.
info: wolfkmod init good
info: bsdkm_example: running wc_aes_test()
info: bsdkm_example: wc_aes_test good

and kldstat:

kldstat
Id Refs Address                Size Name
 1   22 0xffffffff80200000  1f3c6c0 kernel
 2    1 0xffffffff82818000     3220 intpm.ko
 3    1 0xffffffff8281c000     2178 smbus.ko
 4    1 0xffffffff8281f000     430c virtio_console.ko
 5    1 0xffffffff82824000     3360 uhid.ko
 6    1 0xffffffff82828000     3360 wmt.ko
17    2 0xffffffff8282c000   154520 libwolfssl.ko
18    1 0xffffffff82981000     2188 bsd_example.ko

Notice libwolfssl.ko reference count has incremented.

Unload in the opposite order as loading:

sudo kldunload bsd_example.ko
sudo kldunload libwolfssl.ko
kldstat
Id Refs Address                Size Name
 1   18 0xffffffff80200000  1f3c6c0 kernel
 2    1 0xffffffff82818000     3220 intpm.ko
 3    1 0xffffffff8281c000     2178 smbus.ko
 4    1 0xffffffff8281f000     430c virtio_console.ko
 5    1 0xffffffff82824000     3360 uhid.ko
 6    1 0xffffffff82828000     3360 wmt.ko

wolfssl should now have disappeared from the vmstat listing:

# returns nothing
vmstat -m | grep wolf