static int x509_string_cmp( const mbedtls_x509_buf *a, const mbedtls_x509_buf *b )
{
    if( a->tag == b->tag &&
        a->len == b->len &&
        memcmp( a->p, b->p, b->len ) == 0 )
    {
        return( 0 );
    }

    if( ( a->tag == MBEDTLS_ASN1_UTF8_STRING || a->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
        ( b->tag == MBEDTLS_ASN1_UTF8_STRING || b->tag == MBEDTLS_ASN1_PRINTABLE_STRING ) &&
        a->len == b->len &&
        x509_memcasecmp( a->p, b->p, b->len ) == 0 )
    {
        return( 0 );
    }

    return( -1 );
}

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