[openssl] OpenSSL_1_1_1-stable update

[Matt Caswell]

The branch OpenSSL_1_1_1-stable has been updated
       via  9437fe0b01fee8dfd23303d66ad45c2f523a8f25 (commit)
      from  ce283e1011d7b9e08a6c137d8d670ffc77cb2e3b (commit)


- Log -----------------------------------------------------------------
commit 9437fe0b01fee8dfd23303d66ad45c2f523a8f25
Author: Matt Caswell <matt at openssl.org>
Date:   Tue Mar 26 15:25:15 2019 +0000

    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 at openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/8587)
    
    (cherry picked from commit a8274ea351988aa754cb9983b27d7059613ee11e)

-----------------------------------------------------------------------

Summary of changes:
 crypto/evp/digest.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index f78dab7..f405a81 100644
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -150,6 +150,9 @@ 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;
+
     return ctx->update(ctx, data, count);
 }