Always go the legacy route if EVP_MD_CTX_FLAG_NO_INIT is set

If we're using an explicitly fetched digest in an EVP_DigestUpdate
operation, then we should still go the legacy route if
EVP_MD_CTX_FLAG_NO_INIT has been set because we are being used in the
context of a legacy signature algorithm and EVP_DigestInit has not been
called.

This fixes a seg fault in EVP_DigestSignUpdate()

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/10796)

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index 92dca9854b5a155eed403d11e95f0ceece1bdae6..adde3e13aba583bf4a65393fa2e77986645b4d2e 100644 (file)
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -303,7 +303,9 @@ int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t count)
         return 0;
     }
 
-    if (ctx->digest == NULL || ctx->digest->prov == NULL)
+    if (ctx->digest == NULL
+            || ctx->digest->prov == NULL
+            || (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) != 0)
         goto legacy;
 
     if (ctx->digest->dupdate == NULL) {
@@ -422,7 +424,8 @@ int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
         return 0;
     }
 
-    if (in->digest->prov == NULL)
+    if (in->digest->prov == NULL
+            || (in->flags & EVP_MD_CTX_FLAG_NO_INIT) != 0)
         goto legacy;
 
     if (in->digest->dupctx == NULL) {