[openssl] OpenSSL_1_1_1-stable update

[tmraz at fedoraproject.org]

The branch OpenSSL_1_1_1-stable has been updated
       via  5156ecbe691c964ae528c74f94d5b515aeb25542 (commit)
      from  e11072908742e96a1067bb1b9609bfc27ab05835 (commit)


- Log -----------------------------------------------------------------
commit 5156ecbe691c964ae528c74f94d5b515aeb25542
Author: Tomas Mraz <tmraz at fedoraproject.org>
Date:   Tue May 19 10:51:53 2020 +0200

    Avoid potential overflow to the sign bit when shifting left 24 places
    
    Although there are platforms where int is 64 bit, 2GiB large BIGNUMs
    instead of 4GiB should be "big enough for everybody".
    
    Reviewed-by: Richard Levitte <levitte at openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/11857)
    
    (cherry picked from commit 1d05eb55caa8965a151360c2469c463ecd990987)

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

Summary of changes:
 crypto/bn/bn_mpi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/bn/bn_mpi.c b/crypto/bn/bn_mpi.c
index bdbe822415..b6e35a8ed9 100644
--- a/crypto/bn/bn_mpi.c
+++ b/crypto/bn/bn_mpi.c
@@ -45,7 +45,7 @@ BIGNUM *BN_mpi2bn(const unsigned char *d, int n, BIGNUM *ain)
     int neg = 0;
     BIGNUM *a = NULL;
 
-    if (n < 4) {
+    if (n < 4 || (d[0] & 0x80) != 0) {
         BNerr(BN_F_BN_MPI2BN, BN_R_INVALID_LENGTH);
         return NULL;
     }