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bsdkm: kernel example.
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‎kernel/bsdkm/Makefile‎

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# example module name and sources
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KMOD=bsd_example
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SRCS=bsd_example.c
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# path to wolfssl dir
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WOLFSSL_DIR=../../../wolfssl/
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# suppress wolfcrypt/src/misc.c drops const qualifier
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CFLAGS+= -Wno-cast-qual
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CFLAGS+= -Wno-error=cast-qual
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CFLAGS+= -I/usr/include
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CFLAGS+=-I${WOLFSSL_DIR} -DWOLFSSL_USE_OPTIONS_H -DWOLFSSL_CUSTOM_CONFIG
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# point to live kernel kmod dot mk
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.include "/usr/src/sys/conf/kmod.mk"

‎kernel/bsdkm/README.md‎

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# FreeBSD wolfcrypt kernel module example
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## About
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Tested on FreeBSD 14.2:
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```sh
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uname -rsm
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FreeBSD 14.2-RELEASE amd64
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```
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## Build libwolfssl.ko
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```sh
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cd ~/
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git clone https://github.com/philljj/wolfssl.git
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cd ~/wolfssl && git co bsdkm
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./autogen.sh
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./configure --enable-bsdkm --enable-cryptonly --enable-crypttests --enable-all-crypto --disable-asm && make
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file bsdkm/libwolfssl.ko
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```
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Load the kernel module:
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```sh
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sudo kldload bsdkm/libwolfssl.ko
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```
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In dmesg output you should see something like:
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```sh
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dmesg | tail -n10
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PKCS7enveloped test passed!
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PKCS7authenveloped test passed!
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mp test passed!
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prime test passed!
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logging test passed!
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mutex test passed!
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crypto callback test passed!
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Test complete
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wolfCrypt self-test passed.
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info: wolfkmod init good
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```
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and kldstat:
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```sh
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kldstat
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Id Refs Address Size Name
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1 20 0xffffffff80200000 1f3c6c0 kernel
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2 1 0xffffffff82818000 3220 intpm.ko
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3 1 0xffffffff8281c000 2178 smbus.ko
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4 1 0xffffffff8281f000 430c virtio_console.ko
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5 1 0xffffffff82824000 3360 uhid.ko
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6 1 0xffffffff82828000 3360 wmt.ko
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17 1 0xffffffff8282c000 154520 libwolfssl.ko
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```
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wolfssl will also appear in vmstat entries:
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```sh
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vmstat -m | grep wolf
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wolfssl 0 0 1275500 16,32,64,128,256,384,512,1024,2048,4096,8192,16384
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```
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## Build this example
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From this example dir:
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```sh
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make && file bsd_example.ko
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```
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Load it:
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```sh
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sudo kldload ./bsd_example.ko
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```
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dmesg should show:
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```sh
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dmesg | tail -n5
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Test complete
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wolfCrypt self-test passed.
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info: wolfkmod init good
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info: bsdkm_example: running wc_aes_test()
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info: bsdkm_example: wc_aes_test good
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```
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and kldstat:
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```sh
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kldstat
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Id Refs Address Size Name
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1 22 0xffffffff80200000 1f3c6c0 kernel
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2 1 0xffffffff82818000 3220 intpm.ko
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3 1 0xffffffff8281c000 2178 smbus.ko
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4 1 0xffffffff8281f000 430c virtio_console.ko
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5 1 0xffffffff82824000 3360 uhid.ko
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6 1 0xffffffff82828000 3360 wmt.ko
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17 2 0xffffffff8282c000 154520 libwolfssl.ko
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18 1 0xffffffff82981000 2188 bsd_example.ko
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```
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Notice `libwolfssl.ko` reference count has incremented.
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Unload in the opposite order as loading:
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```sh
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sudo kldunload bsd_example.ko
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sudo kldunload libwolfssl.ko
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kldstat
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Id Refs Address Size Name
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1 18 0xffffffff80200000 1f3c6c0 kernel
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2 1 0xffffffff82818000 3220 intpm.ko
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3 1 0xffffffff8281c000 2178 smbus.ko
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4 1 0xffffffff8281f000 430c virtio_console.ko
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5 1 0xffffffff82824000 3360 uhid.ko
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6 1 0xffffffff82828000 3360 wmt.ko
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```
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wolfssl should now have disappeared from the vmstat listing:
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```sh
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# returns nothing
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vmstat -m | grep wolf
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```

‎kernel/bsdkm/bsd_example.c‎

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/* freebsd system includes */
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#include <sys/param.h>
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#include <sys/module.h>
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#include <sys/kernel.h>
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#include <sys/libkern.h>
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#include <sys/malloc.h>
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#include <sys/systm.h>
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/* wolfssl includes */
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#include <wolfssl/options.h>
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#include <wolfssl/wolfcrypt/settings.h>
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#include <wolfssl/wolfcrypt/aes.h>
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#include <wolfssl/wolfcrypt/error-crypt.h>
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MALLOC_DEFINE(M_BSD_EXAMPLE, "bsd_example", "example kernel memory");
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static int wc_aes_test(void);
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const char * ko_name = "bsdkm_example";
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static int
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example_loader(struct module * m, int what, void * arg)
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{
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int ret = 0;
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switch (what) {
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case MOD_LOAD:
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printf("info: %s: running wc_aes_test()\n", ko_name);
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ret = wc_aes_test();
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if (ret != 0) {
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return ECANCELED;
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}
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break;
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case MOD_UNLOAD:
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printf("info: %s: unload\n", ko_name);
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break;
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default:
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printf("info: %s: not implemented: %d\n", ko_name, what);
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return EOPNOTSUPP;
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}
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return 0;
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}
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static int wc_aes_test(void)
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{
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int ret = 0;
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#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_NO_MALLOC)
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Aes *aes = NULL;
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#else
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Aes aes[1];
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#endif
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/* "Now is the time for all " w/o trailing 0 */
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const byte msg[] = {
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0x6e,0x6f,0x77,0x20,0x69,0x73,0x20,0x74,
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0x68,0x65,0x20,0x74,0x69,0x6d,0x65,0x20,
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0x66,0x6f,0x72,0x20,0x61,0x6c,0x6c,0x20
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};
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const byte verify[] =
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{
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0x95,0x94,0x92,0x57,0x5f,0x42,0x81,0x53,
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0x2c,0xcc,0x9d,0x46,0x77,0xa2,0x33,0xcb
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};
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/* padded to 16-bytes */
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const byte key[] = "0123456789abcdef ";
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/* padded to 16-bytes */
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const byte iv[] = "1234567890abcdef ";
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byte cipher[WC_AES_BLOCK_SIZE * 4];
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#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_NO_MALLOC)
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if ((aes = (Aes *)malloc(sizeof(*aes), M_BSD_EXAMPLE, M_WAITOK | M_ZERO)) == NULL) {
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printf("error: %s: xts aes alloc failed\n", ko_name);
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return MEMORY_E;
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}
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#endif
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ret = wc_AesInit(aes, NULL, INVALID_DEVID);
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if (ret) {
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printf("error: %s: wc_AesXtsInit returned: %d\n", ko_name, ret);
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goto wc_aes_test_end;
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}
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ret = wc_AesSetKey(aes, key, WC_AES_BLOCK_SIZE, iv, AES_ENCRYPTION);
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if (ret) {
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printf("error: %s: wc_AesSetKey returned: %d\n", ko_name, ret);
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goto wc_aes_test_end;
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}
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memset(cipher, 0, sizeof(cipher));
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ret = wc_AesCbcEncrypt(aes, cipher, msg, WC_AES_BLOCK_SIZE);
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if (ret) {
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printf("error: %s: wc_AesCbcEncrypt returned: %d\n", ko_name, ret);
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goto wc_aes_test_end;
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}
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if (XMEMCMP(cipher, verify, WC_AES_BLOCK_SIZE)) {
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printf("error: %s: wc_AesCbcDecrypt failed cipher-verify compare\n",
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ko_name);
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ret = -1;
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goto wc_aes_test_end;
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}
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if (ret == 0) {
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printf("info: %s: wc_aes_test good\n", ko_name);
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}
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wc_aes_test_end:
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wc_AesFree(aes);
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#if defined(WOLFSSL_SMALL_STACK) && !defined(WOLFSSL_NO_MALLOC)
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if (aes) {
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free(aes, M_BSD_EXAMPLE);
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aes = NULL;
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}
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#endif
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return ret;
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}
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static moduledata_t hellomod = {
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"bsdkm_example", /* name */
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example_loader, /* loader */
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NULL /* extra data */
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};
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DECLARE_MODULE(bsdkm_example, hellomod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
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MODULE_DEPEND(bsdkm_example, libwolfssl, 1, 1, 1);

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