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>
diff --git a/drivers/crypto/nx/nx-842-powernv.c b/drivers/crypto/nx/nx-842-powernv.c
index 3750e13..9ef51fa 100644
--- a/drivers/crypto/nx/nx-842-powernv.c
+++ b/drivers/crypto/nx/nx-842-powernv.c
@@ -491,7 +491,7 @@
void *wmem)
{
return nx842_powernv_function(in, inlen, out, outlenp,
- wmem, CCW_FC_842_COMP_NOCRC);
+ wmem, CCW_FC_842_COMP_CRC);
}
/**
@@ -519,7 +519,7 @@
void *wmem)
{
return nx842_powernv_function(in, inlen, out, outlenp,
- wmem, CCW_FC_842_DECOMP_NOCRC);
+ wmem, CCW_FC_842_DECOMP_CRC);
}
static int __init nx842_powernv_probe(struct device_node *dn)
diff --git a/drivers/crypto/nx/nx-842-pseries.c b/drivers/crypto/nx/nx-842-pseries.c
index f4cbde0..cddc6d8 100644
--- a/drivers/crypto/nx/nx-842-pseries.c
+++ b/drivers/crypto/nx/nx-842-pseries.c
@@ -234,6 +234,10 @@
dev_dbg(dev, "%s: Out of space in output buffer\n",
__func__);
return -ENOSPC;
+ case 65: /* Calculated CRC doesn't match the passed value */
+ dev_dbg(dev, "%s: CRC mismatch for decompression\n",
+ __func__);
+ return -EINVAL;
case 66: /* Input data contains an illegal template field */
case 67: /* Template indicates data past the end of the input stream */
dev_dbg(dev, "%s: Bad data for decompression (code:%d)\n",
@@ -324,7 +328,7 @@
slout.entries = (struct nx842_slentry *)workmem->slout;
/* Init operation */
- op.flags = NX842_OP_COMPRESS;
+ op.flags = NX842_OP_COMPRESS_CRC;
csbcpb = &workmem->csbcpb;
memset(csbcpb, 0, sizeof(*csbcpb));
op.csbcpb = nx842_get_pa(csbcpb);
@@ -457,7 +461,7 @@
slout.entries = (struct nx842_slentry *)workmem->slout;
/* Init operation */
- op.flags = NX842_OP_DECOMPRESS;
+ op.flags = NX842_OP_DECOMPRESS_CRC;
csbcpb = &workmem->csbcpb;
memset(csbcpb, 0, sizeof(*csbcpb));
op.csbcpb = nx842_get_pa(csbcpb);
diff --git a/lib/842/842.h b/lib/842/842.h
index 7c20003..e0a122bc 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 7ce6894..4051339 100644
--- a/lib/842/842_compress.c
+++ b/lib/842/842_compress.c
@@ -490,6 +490,7 @@
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 @@
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 5446ff0..8881dad2 100644
--- a/lib/842/842_decompress.c
+++ b/lib/842/842_decompress.c
@@ -285,6 +285,7 @@
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 @@
}
} 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;
