[S390] Handling of 4096 bit RSA keys in CRT format.
Also process 4096 bit RSA keys in CRT format. Handle them like the
smaller keys and take care of the zero padding.
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 7fca9c1..8e65447 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -396,8 +396,15 @@
if (copied == 0) {
unsigned int len;
spin_unlock_bh(&zcrypt_device_lock);
- /* len is max 256 / 2 - 120 = 8 */
- len = crt->inputdatalength / 2 - 120;
+ /* len is max 256 / 2 - 120 = 8
+ * For bigger device just assume len of leading
+ * 0s is 8 as stated in the requirements for
+ * ica_rsa_modexpo_crt struct in zcrypt.h.
+ */
+ if (crt->inputdatalength <= 256)
+ len = crt->inputdatalength / 2 - 120;
+ else
+ len = 8;
if (len > sizeof(z1))
return -EFAULT;
z1 = z2 = z3 = 0;
@@ -405,6 +412,7 @@
copy_from_user(&z2, crt->bp_key, len) ||
copy_from_user(&z3, crt->u_mult_inv, len))
return -EFAULT;
+ z1 = z2 = z3 = 0;
copied = 1;
/*
* We have to restart device lookup -