crypto: hisilicon/hpre - ensure private key less than n

The private key of the curve key size generated by stdrng, which maybe
not less than n. Therefore, the private key with the curve key size
minus 1 is generated to ensure that the private key is less than n.

Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/hisilicon/hpre/hpre_crypto.c b/drivers/crypto/hisilicon/hpre/hpre_crypto.c
index 8ede773..9a1c61b 100644 (file)
--- a/drivers/crypto/hisilicon/hpre/hpre_crypto.c
+++ b/drivers/crypto/hisilicon/hpre/hpre_crypto.c
@@ -1392,9 +1392,9 @@ static int hpre_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
                                unsigned int len)
 {
        struct hpre_ctx *ctx = kpp_tfm_ctx(tfm);
+       unsigned int sz, sz_shift, curve_sz;
        struct device *dev = ctx->dev;
        char key[HPRE_ECC_MAX_KSZ];
-       unsigned int sz, sz_shift;
        struct ecdh params;
        int ret;
 
@@ -1406,7 +1406,13 @@ static int hpre_ecdh_set_secret(struct crypto_kpp *tfm, const void *buf,
        /* Use stdrng to generate private key */
        if (!params.key || !params.key_size) {
                params.key = key;
-               params.key_size = hpre_ecdh_get_curvesz(ctx->curve_id);
+               curve_sz = hpre_ecdh_get_curvesz(ctx->curve_id);
+               if (!curve_sz) {
+                       dev_err(dev, "Invalid curve size!\n");
+                       return -EINVAL;
+               }
+
+               params.key_size = curve_sz - 1;
                ret = ecdh_gen_privkey(ctx, &params);
                if (ret)
                        return ret;