From: Shane Lontis <shane.lontis@oracle.com>
Date: Tue, 11 Aug 2020 07:31:11 +0000 (+1000)
Subject: Fix coverity CID #1452773 - Dereference before NULL check in EVP_DigestFinal_ex()
X-Git-Tag: openssl-3.0.0-alpha7~496
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4bec3f6d5103c8244aa50d5d5a5b0374c91e7dfb;p=thirdparty%2Fopenssl.git

Fix coverity CID #1452773 - Dereference before NULL check in EVP_DigestFinal_ex()

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/12628)
---

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index f5ec573828a..f9ba59ca635 100644
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -367,11 +367,18 @@ int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *size)
 /* The caller can assume that this removes any secret data from the context */
 int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, unsigned int *isize)
 {
-    int ret;
+    int ret, sz;
     size_t size = 0;
-    size_t mdsize = EVP_MD_size(ctx->digest);
+    size_t mdsize = 0;
 
-    if (ctx->digest == NULL || ctx->digest->prov == NULL)
+    if (ctx->digest == NULL)
+        return 0;
+
+    sz = EVP_MD_size(ctx->digest);
+    if (sz < 0)
+        return 0;
+    mdsize = sz;
+    if (ctx->digest->prov == NULL)
         goto legacy;
 
     if (ctx->digest->dfinal == NULL) {