2019-07-18 23:59:48

by Iuliana Prodan

[permalink] [raw]
Subject: [PATCH v2 08/14] crypto: caam - update rfc4106 sh desc to support zero length input

Update share descriptor for rfc4106 to skip instructions in case
cryptlen is zero. If no instructions are jumped the DECO hangs and a
timeout error is thrown.

Signed-off-by: Iuliana Prodan <[email protected]>
---
drivers/crypto/caam/caamalg_desc.c | 46 +++++++++++++++++++++++++-------------
drivers/crypto/caam/caamalg_desc.h | 2 +-
2 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/drivers/crypto/caam/caamalg_desc.c b/drivers/crypto/caam/caamalg_desc.c
index 7253183..99f419a 100644
--- a/drivers/crypto/caam/caamalg_desc.c
+++ b/drivers/crypto/caam/caamalg_desc.c
@@ -843,13 +843,16 @@ EXPORT_SYMBOL(cnstr_shdsc_gcm_decap);
* @ivsize: initialization vector size
* @icvsize: integrity check value (ICV) size (truncated or full)
* @is_qi: true when called from caam/qi
+ *
+ * Input sequence: AAD | PTXT
+ * Output sequence: AAD | CTXT | ICV
+ * AAD length (assoclen), which includes the IV length, is available in Math3.
*/
void cnstr_shdsc_rfc4106_encap(u32 * const desc, struct alginfo *cdata,
unsigned int ivsize, unsigned int icvsize,
const bool is_qi)
{
- u32 *key_jump_cmd;
-
+ u32 *key_jump_cmd, *zero_cryptlen_jump_cmd, *skip_instructions;
init_sh_desc(desc, HDR_SHARE_SERIAL);

/* Skip key loading if it is loaded due to sharing */
@@ -890,26 +893,25 @@ void cnstr_shdsc_rfc4106_encap(u32 * const desc, struct alginfo *cdata,
}

append_math_sub_imm_u32(desc, VARSEQINLEN, REG3, IMM, ivsize);
- append_math_add(desc, VARSEQOUTLEN, ZERO, REG3, CAAM_CMD_SZ);
+ append_math_add(desc, VARSEQOUTLEN, REG0, REG3, CAAM_CMD_SZ);

- /* Read assoc data */
+ /* Skip AAD */
+ append_seq_fifo_store(desc, 0, FIFOST_TYPE_SKIP | FIFOLDST_VLF);
+
+ /* Read cryptlen and set this value into VARSEQOUTLEN */
+ append_math_sub(desc, VARSEQOUTLEN, SEQINLEN, REG3, CAAM_CMD_SZ);
+
+ /* If cryptlen is ZERO jump to AAD command */
+ zero_cryptlen_jump_cmd = append_jump(desc, JUMP_TEST_ALL |
+ JUMP_COND_MATH_Z);
+
+ /* Read AAD data */
append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLDST_VLF |
FIFOLD_TYPE_AAD | FIFOLD_TYPE_FLUSH1);

/* Skip IV */
append_seq_fifo_load(desc, ivsize, FIFOLD_CLASS_SKIP);
-
- /* Will read cryptlen bytes */
- append_math_sub(desc, VARSEQINLEN, SEQINLEN, REG0, CAAM_CMD_SZ);
-
- /* Workaround for erratum A-005473 (simultaneous SEQ FIFO skips) */
- append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLD_TYPE_MSG);
-
- /* Skip assoc data */
- append_seq_fifo_store(desc, 0, FIFOST_TYPE_SKIP | FIFOLDST_VLF);
-
- /* cryptlen = seqoutlen - assoclen */
- append_math_sub(desc, VARSEQOUTLEN, VARSEQINLEN, REG0, CAAM_CMD_SZ);
+ append_math_add(desc, VARSEQINLEN, VARSEQOUTLEN, REG0, CAAM_CMD_SZ);

/* Write encrypted data */
append_seq_fifo_store(desc, 0, FIFOST_TYPE_MESSAGE_DATA | FIFOLDST_VLF);
@@ -918,6 +920,18 @@ void cnstr_shdsc_rfc4106_encap(u32 * const desc, struct alginfo *cdata,
append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLDST_VLF |
FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST1);

+ /* Jump instructions to avoid double reading of AAD */
+ skip_instructions = append_jump(desc, JUMP_TEST_ALL);
+
+ /* There is no input data, cryptlen = 0 */
+ set_jump_tgt_here(desc, zero_cryptlen_jump_cmd);
+
+ /* Read AAD */
+ append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLDST_VLF |
+ FIFOLD_TYPE_AAD | FIFOLD_TYPE_LAST1);
+
+ set_jump_tgt_here(desc, skip_instructions);
+
/* Write ICV */
append_seq_store(desc, icvsize, LDST_CLASS_1_CCB |
LDST_SRCDST_BYTE_CONTEXT);
diff --git a/drivers/crypto/caam/caamalg_desc.h b/drivers/crypto/caam/caamalg_desc.h
index da4a4ee..a49fb53 100644
--- a/drivers/crypto/caam/caamalg_desc.h
+++ b/drivers/crypto/caam/caamalg_desc.h
@@ -31,7 +31,7 @@
#define DESC_QI_GCM_DEC_LEN (DESC_GCM_DEC_LEN + 3 * CAAM_CMD_SZ)

#define DESC_RFC4106_BASE (3 * CAAM_CMD_SZ)
-#define DESC_RFC4106_ENC_LEN (DESC_RFC4106_BASE + 13 * CAAM_CMD_SZ)
+#define DESC_RFC4106_ENC_LEN (DESC_RFC4106_BASE + 15 * CAAM_CMD_SZ)
#define DESC_RFC4106_DEC_LEN (DESC_RFC4106_BASE + 13 * CAAM_CMD_SZ)
#define DESC_QI_RFC4106_ENC_LEN (DESC_RFC4106_ENC_LEN + 5 * CAAM_CMD_SZ)
#define DESC_QI_RFC4106_DEC_LEN (DESC_RFC4106_DEC_LEN + 5 * CAAM_CMD_SZ)
--
2.1.0


2019-07-19 16:46:53

by Horia Geanta

[permalink] [raw]
Subject: Re: [PATCH v2 08/14] crypto: caam - update rfc4106 sh desc to support zero length input

On 7/19/2019 2:58 AM, Iuliana Prodan wrote:
> Update share descriptor for rfc4106 to skip instructions in case
> cryptlen is zero. If no instructions are jumped the DECO hangs and a
> timeout error is thrown.
>
> Signed-off-by: Iuliana Prodan <[email protected]>
> ---
> drivers/crypto/caam/caamalg_desc.c | 46 +++++++++++++++++++++++++-------------
> drivers/crypto/caam/caamalg_desc.h | 2 +-
> 2 files changed, 31 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/crypto/caam/caamalg_desc.c b/drivers/crypto/caam/caamalg_desc.c
> index 7253183..99f419a 100644
> --- a/drivers/crypto/caam/caamalg_desc.c
> +++ b/drivers/crypto/caam/caamalg_desc.c
> @@ -843,13 +843,16 @@ EXPORT_SYMBOL(cnstr_shdsc_gcm_decap);
> * @ivsize: initialization vector size
> * @icvsize: integrity check value (ICV) size (truncated or full)
> * @is_qi: true when called from caam/qi
> + *
> + * Input sequence: AAD | PTXT
> + * Output sequence: AAD | CTXT | ICV
> + * AAD length (assoclen), which includes the IV length, is available in Math3.
> */
> void cnstr_shdsc_rfc4106_encap(u32 * const desc, struct alginfo *cdata,
> unsigned int ivsize, unsigned int icvsize,
> const bool is_qi)
> {
> - u32 *key_jump_cmd;
> -
> + u32 *key_jump_cmd, *zero_cryptlen_jump_cmd, *skip_instructions;
> init_sh_desc(desc, HDR_SHARE_SERIAL);
>
> /* Skip key loading if it is loaded due to sharing */
> @@ -890,26 +893,25 @@ void cnstr_shdsc_rfc4106_encap(u32 * const desc, struct alginfo *cdata,
> }
>
> append_math_sub_imm_u32(desc, VARSEQINLEN, REG3, IMM, ivsize);
> - append_math_add(desc, VARSEQOUTLEN, ZERO, REG3, CAAM_CMD_SZ);
> + append_math_add(desc, VARSEQOUTLEN, REG0, REG3, CAAM_CMD_SZ);
>
Why is this needed?
-all math registers are zero when descriptors start execution
-all caam hw revisions have support for math instruction
with ZERO as first operand
-descriptor size stays the same

> - /* Read assoc data */
> + /* Skip AAD */
> + append_seq_fifo_store(desc, 0, FIFOST_TYPE_SKIP | FIFOLDST_VLF);
> +
> + /* Read cryptlen and set this value into VARSEQOUTLEN */
> + append_math_sub(desc, VARSEQOUTLEN, SEQINLEN, REG3, CAAM_CMD_SZ);
> +
> + /* If cryptlen is ZERO jump to AAD command */
> + zero_cryptlen_jump_cmd = append_jump(desc, JUMP_TEST_ALL |
> + JUMP_COND_MATH_Z);
> +
> + /* Read AAD data */
> append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLDST_VLF |
> FIFOLD_TYPE_AAD | FIFOLD_TYPE_FLUSH1);
>
> /* Skip IV */
> append_seq_fifo_load(desc, ivsize, FIFOLD_CLASS_SKIP);
> -
> - /* Will read cryptlen bytes */
> - append_math_sub(desc, VARSEQINLEN, SEQINLEN, REG0, CAAM_CMD_SZ);
> -
> - /* Workaround for erratum A-005473 (simultaneous SEQ FIFO skips) */
> - append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLD_TYPE_MSG);
> -
Erratum workaround is dropped without any explanation.

The trigger condition (SKIPs both in input and output sequence) still exists.
The descriptor should be validated on a caam with erratum not fixed (era < 6).

Horia