Bump the DH key size to 256 bytes to avoid EINVAL on my kernel.

src/test/keyctl.c

@@ -13,7 +13,7 @@ struct rr_keyctl_dh_params {
 };
 
 int main(void) {
- char buffer[192];
+ char buffer[256];
 
  char* data = "Test Data";
  key_serial_t key = syscall(SYS_add_key, "user", "RR Test key", data,
@@ -35,9 +35,9 @@ int main(void) {
  test_assert(0 == syscall(SYS_keyctl, KEYCTL_INVALIDATE, key));
 
 #ifdef KEYCTL_DH_COMPUTE
- uint8_t base[192] = { 1 };
+ uint8_t base[256] = { 1 };
  // 'prime' must be at least 1536 bits or we get EINVAL.
- uint8_t prime[192] = { 7 }; // Not prime but we should be OK
+ uint8_t prime[256] = { 7 }; // Not prime but we should be OK
  uint8_t private = 1; // The world's worst private key
  base[191] = 'x';