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authorHaren Myneni <haren@linux.vnet.ibm.com>2015-10-08 13:45:51 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2015-10-14 22:23:17 +0800
commitea0b3984c1cc8b28de27a3bec285102b4e366a4c (patch)
treeb0134466a5b790d4091dc16065257a00ea24bf00 /lib
parentf5128432b08c3e263e1a7ce709d686b1ded51131 (diff)
downloadlwn-ea0b3984c1cc8b28de27a3bec285102b4e366a4c.tar.gz
lwn-ea0b3984c1cc8b28de27a3bec285102b4e366a4c.zip
crypto: 842 - Add CRC and validation support
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>
Diffstat (limited to 'lib')
-rw-r--r--lib/842/842.h2
-rw-r--r--lib/842/842_compress.c13
-rw-r--r--lib/842/842_decompress.c17
3 files changed, 32 insertions, 0 deletions
diff --git a/lib/842/842.h b/lib/842/842.h
index 7c200030acf7..e0a122bc1cdb 100644
--- a/lib/842/842.h
+++ b/lib/842/842.h
@@ -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)
diff --git a/lib/842/842_compress.c b/lib/842/842_compress.c
index 7ce68948e68c..4051339bdfbd 100644
--- a/lib/842/842_compress.c
+++ b/lib/842/842_compress.c
@@ -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--;
diff --git a/lib/842/842_decompress.c b/lib/842/842_decompress.c
index 5446ff0c9ba0..8881dad2a6a0 100644
--- a/lib/842/842_decompress.c
+++ b/lib/842/842_decompress.c
@@ -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;