static int x509_memcasecmp( const void *s1, const void *s2, size_t len )
{
    size_t i;
    unsigned char diff;
    const unsigned char *n1 = s1, *n2 = s2;

    for( i = 0; i < len; i++ )
    {
        diff = n1[i] ^ n2[i];

        if( diff == 0 )
            continue;

        if( diff == 32 &&
            ( ( n1[i] >= 'a' && n1[i] <= 'z' ) ||
              ( n1[i] >= 'A' && n1[i] <= 'Z' ) ) )
        {
            continue;
        }

        return( -1 );
    }

    return( 0 );
}

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.