[PATCH 5.6 183/254] crypto: caam/qi2 - fix chacha20 data size error

From: Greg Kroah-Hartman
Date: Thu Apr 16 2020 - 10:27:49 EST


From: Horia GeantÄ <horia.geanta@xxxxxxx>

commit 3a5a9e1ef37b030b836d92df8264f840988f4a38 upstream.

HW generates a Data Size error for chacha20 requests that are not
a multiple of 64B, since algorithm state (AS) does not have
the FINAL bit set.

Since updating req->iv (for chaining) is not required,
modify skcipher descriptors to set the FINAL bit for chacha20.

[Note that for skcipher decryption we know that ctx1_iv_off is 0,
which allows for an optimization by not checking algorithm type,
since append_dec_op1() sets FINAL bit for all algorithms except AES.]

Also drop the descriptor operations that save the IV.
However, in order to keep code logic simple, things like
S/G tables generation etc. are not touched.

Cc: <stable@xxxxxxxxxxxxxxx> # v5.3+
Fixes: 334d37c9e263 ("crypto: caam - update IV using HW support")
Signed-off-by: Horia GeantÄ <horia.geanta@xxxxxxx>
Tested-by: Valentin Ciocoi Radulescu <valentin.ciocoi@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/crypto/caam/caamalg_desc.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

--- a/drivers/crypto/caam/caamalg_desc.c
+++ b/drivers/crypto/caam/caamalg_desc.c
@@ -1379,6 +1379,9 @@ void cnstr_shdsc_skcipher_encap(u32 * co
const u32 ctx1_iv_off)
{
u32 *key_jump_cmd;
+ u32 options = cdata->algtype | OP_ALG_AS_INIT | OP_ALG_ENCRYPT;
+ bool is_chacha20 = ((cdata->algtype & OP_ALG_ALGSEL_MASK) ==
+ OP_ALG_ALGSEL_CHACHA20);

init_sh_desc(desc, HDR_SHARE_SERIAL | HDR_SAVECTX);
/* Skip if already shared */
@@ -1417,14 +1420,15 @@ void cnstr_shdsc_skcipher_encap(u32 * co
LDST_OFFSET_SHIFT));

/* Load operation */
- append_operation(desc, cdata->algtype | OP_ALG_AS_INIT |
- OP_ALG_ENCRYPT);
+ if (is_chacha20)
+ options |= OP_ALG_AS_FINALIZE;
+ append_operation(desc, options);

/* Perform operation */
skcipher_append_src_dst(desc);

/* Store IV */
- if (ivsize)
+ if (!is_chacha20 && ivsize)
append_seq_store(desc, ivsize, LDST_SRCDST_BYTE_CONTEXT |
LDST_CLASS_1_CCB | (ctx1_iv_off <<
LDST_OFFSET_SHIFT));
@@ -1451,6 +1455,8 @@ void cnstr_shdsc_skcipher_decap(u32 * co
const u32 ctx1_iv_off)
{
u32 *key_jump_cmd;
+ bool is_chacha20 = ((cdata->algtype & OP_ALG_ALGSEL_MASK) ==
+ OP_ALG_ALGSEL_CHACHA20);

init_sh_desc(desc, HDR_SHARE_SERIAL | HDR_SAVECTX);
/* Skip if already shared */
@@ -1499,7 +1505,7 @@ void cnstr_shdsc_skcipher_decap(u32 * co
skcipher_append_src_dst(desc);

/* Store IV */
- if (ivsize)
+ if (!is_chacha20 && ivsize)
append_seq_store(desc, ivsize, LDST_SRCDST_BYTE_CONTEXT |
LDST_CLASS_1_CCB | (ctx1_iv_off <<
LDST_OFFSET_SHIFT));