Coverity: fix 1506298: negative returns

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18587)

diff --git a/crypto/dh/dh_ameth.c b/crypto/dh/dh_ameth.c
index 6ec582f5f38d830bc96ca0b06b41d47d33a5d0f9..8430872a9ab6b257c91794f04ee841e2c2ddd6cc 100644 (file)
--- a/crypto/dh/dh_ameth.c
+++ b/crypto/dh/dh_ameth.c
@@ -207,6 +207,11 @@ static int dh_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
 
     ASN1_STRING_clear_free(prkey);
 
+    if (dplen <= 0) {
+        ERR_raise(ERR_LIB_DH, DH_R_BN_ERROR);
+        goto err;
+    }
+
     if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
                          V_ASN1_SEQUENCE, params, dp, dplen)) {
         OPENSSL_clear_free(dp, dplen);