[PATCH] remove undefined behavior in ssl/s3_srvr.c

[Pascal Junod]

Dear OpenSSL developers community,

The attached patch remove two conditions in for() loops that can cause
an undefined behavior leading to an out-of-bound read in ssl/s3_srvr.c.
However, I don't see any security implication here.

I have discovered them using the -fsanitize=undefined option of LLVM.

Cheers,

Pascal

1841,1843c1841,1847
<               for (i=0; r[i] != NULL && i<4; i++)
<                       {
<                       nr[i]=BN_num_bytes(r[i]);
---
>               for (i=0; i<4; i++)
>                   {
>                         if (r[i] == NULL) {
>                               break;
>                         }
>                       
>                         nr[i]=BN_num_bytes(r[i]);
1850c1854
<                       }
---
>                   }
1877,1878c1881,1885
<               for (i=0; r[i] != NULL && i<4; i++)
<                       {
---
>               for (i=0; i<4; i++)
>                   {
>                       if (r[i] == NULL) {
>                           break;
>                       }
1890c1897
<                       }
---
>                   }