From a8274ea351988aa754cb9983b27d7059613ee11e Mon Sep 17 00:00:00 2001
From: Matt Caswell <matt@openssl.org>
Date: Tue, 26 Mar 2019 15:25:15 +0000
Subject: [PATCH] Tolerate 0 byte input length for Update functions
We treat that as automatic success. Other EVP_*Update functions already do
this (e.g. EVP_EncryptUpdate, EVP_DecryptUpdate etc). EVP_EncodeUpdate is
a bit of an anomoly. That treats 0 byte input length as an error.
Fixes #8576
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8587)
---
crypto/evp/digest.c | 3 +++
crypto/evp/mac_lib.c | 2 ++
2 files changed, 5 insertions(+)
diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index d4b481443c..7b4972553b 100644
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -259,6 +259,9 @@ int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl)
int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t count)
{
+ if (count == 0)
+ return 1;
+
if (ctx->digest == NULL || ctx->digest->prov == NULL)
goto legacy;
diff --git a/crypto/evp/mac_lib.c b/crypto/evp/mac_lib.c
index 2f46277bf0..39efff0842 100644
--- a/crypto/evp/mac_lib.c
+++ b/crypto/evp/mac_lib.c
@@ -82,6 +82,8 @@ int EVP_MAC_init(EVP_MAC_CTX *ctx)
int EVP_MAC_update(EVP_MAC_CTX *ctx, const unsigned char *data, size_t datalen)
{
+ if (datalen == 0)
+ return 1;
return ctx->meth->update(ctx->data, data, datalen);
}
--
2.25.1