* [PATCH 1/2] digsig: remove unnecessary memory allocation and copying
2013-01-30 9:30 [PATCH 0/2] digsig and mpi cleanups Dmitry Kasatkin
@ 2013-01-30 9:30 ` Dmitry Kasatkin
2013-02-01 5:31 ` James Morris
2013-01-30 9:30 ` [PATCH 2/2] mpilib: use DIV_ROUND_UP and remove unused macros Dmitry Kasatkin
1 sibling, 1 reply; 5+ messages in thread
From: Dmitry Kasatkin @ 2013-01-30 9:30 UTC (permalink / raw)
To: linux-security-module, linux-crypto; +Cc: jmorris
In existing use case, copying of the decoded data is unnecessary in
pkcs_1_v1_5_decode_emsa. It is just enough to get pointer to the message.
Removing copying and extra buffer allocation.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
---
lib/digsig.c | 41 ++++++++++++++---------------------------
1 file changed, 14 insertions(+), 27 deletions(-)
diff --git a/lib/digsig.c b/lib/digsig.c
index dc2be7e..2f31e6a 100644
--- a/lib/digsig.c
+++ b/lib/digsig.c
@@ -30,11 +30,10 @@
static struct crypto_shash *shash;
-static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
- unsigned long msglen,
- unsigned long modulus_bitlen,
- unsigned char *out,
- unsigned long *outlen)
+static const char *pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
+ unsigned long msglen,
+ unsigned long modulus_bitlen,
+ unsigned long *outlen)
{
unsigned long modulus_len, ps_len, i;
@@ -42,11 +41,11 @@ static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
/* test message size */
if ((msglen > modulus_len) || (modulus_len < 11))
- return -EINVAL;
+ return NULL;
/* separate encoded message */
- if ((msg[0] != 0x00) || (msg[1] != (unsigned char)1))
- return -EINVAL;
+ if (msg[0] != 0x00 || msg[1] != 0x01)
+ return NULL;
for (i = 2; i < modulus_len - 1; i++)
if (msg[i] != 0xFF)
@@ -56,19 +55,13 @@ static int pkcs_1_v1_5_decode_emsa(const unsigned char *msg,
if (msg[i] != 0)
/* There was no octet with hexadecimal value 0x00
to separate ps from m. */
- return -EINVAL;
+ return NULL;
ps_len = i - 2;
- if (*outlen < (msglen - (2 + ps_len + 1))) {
- *outlen = msglen - (2 + ps_len + 1);
- return -EOVERFLOW;
- }
-
*outlen = (msglen - (2 + ps_len + 1));
- memcpy(out, &msg[2 + ps_len + 1], *outlen);
- return 0;
+ return msg + 2 + ps_len + 1;
}
/*
@@ -83,7 +76,8 @@ static int digsig_verify_rsa(struct key *key,
unsigned long mlen, mblen;
unsigned nret, l;
int head, i;
- unsigned char *out1 = NULL, *out2 = NULL;
+ unsigned char *out1 = NULL;
+ const char *m;
MPI in = NULL, res = NULL, pkey[2];
uint8_t *p, *datap, *endp;
struct user_key_payload *ukp;
@@ -120,7 +114,7 @@ static int digsig_verify_rsa(struct key *key,
}
mblen = mpi_get_nbits(pkey[0]);
- mlen = (mblen + 7)/8;
+ mlen = DIV_ROUND_UP(mblen, 8);
if (mlen == 0)
goto err;
@@ -129,10 +123,6 @@ static int digsig_verify_rsa(struct key *key,
if (!out1)
goto err;
- out2 = kzalloc(mlen, GFP_KERNEL);
- if (!out2)
- goto err;
-
nret = siglen;
in = mpi_read_from_buffer(sig, &nret);
if (!in)
@@ -164,18 +154,15 @@ static int digsig_verify_rsa(struct key *key,
kfree(p);
- err = pkcs_1_v1_5_decode_emsa(out1, len, mblen, out2, &len);
- if (err)
- goto err;
+ m = pkcs_1_v1_5_decode_emsa(out1, len, mblen, &len);
- if (len != hlen || memcmp(out2, h, hlen))
+ if (!m || len != hlen || memcmp(m, h, hlen))
err = -EINVAL;
err:
mpi_free(in);
mpi_free(res);
kfree(out1);
- kfree(out2);
while (--i >= 0)
mpi_free(pkey[i]);
err1:
--
1.7.10.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/2] mpilib: use DIV_ROUND_UP and remove unused macros
2013-01-30 9:30 [PATCH 0/2] digsig and mpi cleanups Dmitry Kasatkin
2013-01-30 9:30 ` [PATCH 1/2] digsig: remove unnecessary memory allocation and copying Dmitry Kasatkin
@ 2013-01-30 9:30 ` Dmitry Kasatkin
2013-02-01 5:31 ` James Morris
1 sibling, 1 reply; 5+ messages in thread
From: Dmitry Kasatkin @ 2013-01-30 9:30 UTC (permalink / raw)
To: linux-security-module, linux-crypto; +Cc: jmorris, Andy Shevchenko
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Remove MIN, MAX and ABS macros that are duplicates kernel's native
implementation.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
lib/mpi/mpi-internal.h | 4 ----
lib/mpi/mpicoder.c | 8 ++++----
2 files changed, 4 insertions(+), 8 deletions(-)
diff --git a/lib/mpi/mpi-internal.h b/lib/mpi/mpi-internal.h
index 77adcf6..60cf765 100644
--- a/lib/mpi/mpi-internal.h
+++ b/lib/mpi/mpi-internal.h
@@ -65,10 +65,6 @@
typedef mpi_limb_t *mpi_ptr_t; /* pointer to a limb */
typedef int mpi_size_t; /* (must be a signed type) */
-#define ABS(x) (x >= 0 ? x : -x)
-#define MIN(l, o) ((l) < (o) ? (l) : (o))
-#define MAX(h, i) ((h) > (i) ? (h) : (i))
-
static inline int RESIZE_IF_NEEDED(MPI a, unsigned b)
{
if (a->alloced < b)
diff --git a/lib/mpi/mpicoder.c b/lib/mpi/mpicoder.c
index 3962b7f..5f9c44c 100644
--- a/lib/mpi/mpicoder.c
+++ b/lib/mpi/mpicoder.c
@@ -52,7 +52,7 @@ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes)
else
nbits = 0;
- nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+ nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB);
val = mpi_alloc(nlimbs);
if (!val)
return NULL;
@@ -96,8 +96,8 @@ MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread)
buffer += 2;
nread = 2;
- nbytes = (nbits + 7) / 8;
- nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+ nbytes = DIV_ROUND_UP(nbits, 8);
+ nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB);
val = mpi_alloc(nlimbs);
if (!val)
return NULL;
@@ -193,7 +193,7 @@ int mpi_set_buffer(MPI a, const void *xbuffer, unsigned nbytes, int sign)
int nlimbs;
int i;
- nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+ nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB);
if (RESIZE_IF_NEEDED(a, nlimbs) < 0)
return -ENOMEM;
a->sign = sign;
--
1.7.10.4
^ permalink raw reply related [flat|nested] 5+ messages in thread