linux/arch/arm64
Eric Biggers 674f368a95 crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN
The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to
make the ->setkey() functions provide more information about errors.

However, no one actually checks for this flag, which makes it pointless.

Also, many algorithms fail to set this flag when given a bad length key.
Reviewing just the generic implementations, this is the case for
aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309,
rfc7539, rfc7539esp, salsa20, seqiv, and xcbc.  But there are probably
many more in arch/*/crypto/ and drivers/crypto/.

Some algorithms can even set this flag when the key is the correct
length.  For example, authenc and authencesn set it when the key payload
is malformed in any way (not just a bad length), the atmel-sha and ccree
drivers can set it if a memory allocation fails, and the chelsio driver
sets it for bad auth tag lengths, not just bad key lengths.

So even if someone actually wanted to start checking this flag (which
seems unlikely, since it's been unused for a long time), there would be
a lot of work needed to get it working correctly.  But it would probably
be much better to go back to the drawing board and just define different
return values, like -EINVAL if the key is invalid for the algorithm vs.
-EKEYREJECTED if the key was rejected by a policy like "no weak keys".
That would be much simpler, less error-prone, and easier to test.

So just remove this flag.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-01-09 11:30:53 +08:00
..
boot Merge mainline/master into arm/fixes 2019-12-05 13:18:54 -08:00
configs arm64: defconfig: re-run savedefconfig 2019-12-05 13:20:17 -08:00
crypto crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN 2020-01-09 11:30:53 +08:00
include arm64 updates for 5.5: 2019-12-06 14:18:01 -08:00
kernel arm64 updates for 5.5: 2019-12-06 14:18:01 -08:00
kvm arm64 updates for 5.5: 2019-12-06 14:18:01 -08:00
lib arm64: uaccess: Remove uaccess_*_not_uao asm macros 2019-11-20 18:51:54 +00:00
mm arm64 updates for 5.5: 2019-12-06 14:18:01 -08:00
net arm64: bpf: optimize modulo operation 2019-09-03 15:44:40 +02:00
xen xen/efi: have a common runtime setup function 2019-10-02 10:31:07 -04:00
Kbuild arm64: add arch/arm64/Kbuild 2019-08-21 18:47:15 +01:00
Kconfig dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
Kconfig.debug treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Kconfig.platforms i.MX SoC update for 5.5: 2019-11-06 07:46:42 -08:00
Makefile arm64: implement ftrace with regs 2019-11-06 14:17:35 +00:00