From: Tianjia Zhang tianjia.zhang@linux.alibaba.com
[ Upstream commit 1bc608b4655b8b1491fb100f4cf4f15ae64a8698 ]
This is an algorithm optimization. The reset operation when setting the public key is repeated and redundant, so remove it. At the same time, `sm2_ecc_os2ec()` is optimized to make the function more simpler and more in line with the Linux code style.
Signed-off-by: Tianjia Zhang tianjia.zhang@linux.alibaba.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/sm2.c | 75 ++++++++++++++++++++-------------------------------- 1 file changed, 29 insertions(+), 46 deletions(-)
diff --git a/crypto/sm2.c b/crypto/sm2.c index 767e160333f6..b21addc3ac06 100644 --- a/crypto/sm2.c +++ b/crypto/sm2.c @@ -119,12 +119,6 @@ static void sm2_ec_ctx_deinit(struct mpi_ec_ctx *ec) memset(ec, 0, sizeof(*ec)); }
-static int sm2_ec_ctx_reset(struct mpi_ec_ctx *ec) -{ - sm2_ec_ctx_deinit(ec); - return sm2_ec_ctx_init(ec); -} - /* RESULT must have been initialized and is set on success to the * point given by VALUE. */ @@ -132,55 +126,48 @@ static int sm2_ecc_os2ec(MPI_POINT result, MPI value) { int rc; size_t n; - const unsigned char *buf; - unsigned char *buf_memory; + unsigned char *buf; MPI x, y;
- n = (mpi_get_nbits(value)+7)/8; - buf_memory = kmalloc(n, GFP_KERNEL); - rc = mpi_print(GCRYMPI_FMT_USG, buf_memory, n, &n, value); - if (rc) { - kfree(buf_memory); - return rc; - } - buf = buf_memory; + n = MPI_NBYTES(value); + buf = kmalloc(n, GFP_KERNEL); + if (!buf) + return -ENOMEM;
- if (n < 1) { - kfree(buf_memory); - return -EINVAL; - } - if (*buf != 4) { - kfree(buf_memory); - return -EINVAL; /* No support for point compression. */ - } - if (((n-1)%2)) { - kfree(buf_memory); - return -EINVAL; - } - n = (n-1)/2; + rc = mpi_print(GCRYMPI_FMT_USG, buf, n, &n, value); + if (rc) + goto err_freebuf; + + rc = -EINVAL; + if (n < 1 || ((n - 1) % 2)) + goto err_freebuf; + /* No support for point compression */ + if (*buf != 0x4) + goto err_freebuf; + + rc = -ENOMEM; + n = (n - 1) / 2; x = mpi_read_raw_data(buf + 1, n); - if (!x) { - kfree(buf_memory); - return -ENOMEM; - } + if (!x) + goto err_freebuf; y = mpi_read_raw_data(buf + 1 + n, n); - kfree(buf_memory); - if (!y) { - mpi_free(x); - return -ENOMEM; - } + if (!y) + goto err_freex;
mpi_normalize(x); mpi_normalize(y); - mpi_set(result->x, x); mpi_set(result->y, y); mpi_set_ui(result->z, 1);
- mpi_free(x); - mpi_free(y); + rc = 0;
- return 0; + mpi_free(y); +err_freex: + mpi_free(x); +err_freebuf: + kfree(buf); + return rc; }
struct sm2_signature_ctx { @@ -399,10 +386,6 @@ static int sm2_set_pub_key(struct crypto_akcipher *tfm, MPI a; int rc;
- rc = sm2_ec_ctx_reset(ec); - if (rc) - return rc; - ec->Q = mpi_point_new(0); if (!ec->Q) return -ENOMEM;