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crypto: 842 - Add CRC and validation support

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This patch adds CRC generation and validation support for nx-842.
Add CRC flag so that nx842 coprocessor includes CRC during compression
and validates during decompression.

Also changes in 842 SW compression to append CRC value at the end
of template and checks during decompression.

Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Haren Myneni
2015-10-08 13:45:51 -07:00
committed by Herbert Xu
parent f5128432b0
commit ea0b3984c1
5 changed files with 40 additions and 4 deletions
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2
lib/842/842.h
View File

@@ -76,6 +76,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/crc32.h>
#include <asm/unaligned.h>
#include <linux/sw842.h>
@@ -98,6 +99,7 @@
#define I2_BITS (8)
#define I4_BITS (9)
#define I8_BITS (8)
#define CRC_BITS (32)
#define REPEAT_BITS_MAX (0x3f)
#define SHORT_DATA_BITS_MAX (0x7)

13
lib/842/842_compress.c
View File

@@ -490,6 +490,7 @@ int sw842_compress(const u8 *in, unsigned int ilen,
int ret;
u64 last, next, pad, total;
u8 repeat_count = 0;
u32 crc;
BUILD_BUG_ON(sizeof(*p) > SW842_MEM_COMPRESS);
@@ -580,6 +581,18 @@ skip_comp:
if (ret)
return ret;
/*
* crc(0:31) is appended to target data starting with the next
* bit after End of stream template.
* nx842 calculates CRC for data in big-endian format. So doing
* same here so that sw842 decompression can be used for both
* compressed data.
*/
crc = crc32_be(0, in, ilen);
ret = add_bits(p, crc, CRC_BITS);
if (ret)
return ret;
if (p->bit) {
p->out++;
p->olen--;

17
lib/842/842_decompress.c
View File

@@ -285,6 +285,7 @@ int sw842_decompress(const u8 *in, unsigned int ilen,
struct sw842_param p;
int ret;
u64 op, rep, tmp, bytes, total;
u64 crc;
p.in = (u8 *)in;
p.bit = 0;
@@ -375,6 +376,22 @@ int sw842_decompress(const u8 *in, unsigned int ilen,
}
} while (op != OP_END);
/*
* crc(0:31) is saved in compressed data starting with the
* next bit after End of stream template.
*/
ret = next_bits(&p, &crc, CRC_BITS);
if (ret)
return ret;
/*
* Validate CRC saved in compressed data.
*/
if (crc != (u64)crc32_be(0, out, total - p.olen)) {
pr_debug("CRC mismatch for decompression\n");
return -EINVAL;
}
if (unlikely((total - p.olen) > UINT_MAX))
return -ENOSPC;