static int x509_get_attr_type_value( unsigned char **p,
                                     const unsigned char *end,
                                     x509_name *cur )
{
    int ret;
    size_t len;
    x509_buf *oid;
    x509_buf *val;

    if( ( ret = asn1_get_tag( p, end, &len,
            ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
        return( POLARSSL_ERR_X509_INVALID_NAME + ret );

    if( ( end - *p ) < 1 )
        return( POLARSSL_ERR_X509_INVALID_NAME +
                POLARSSL_ERR_ASN1_OUT_OF_DATA );

    oid = &cur->oid;
    oid->tag = **p;

    if( ( ret = asn1_get_tag( p, end, &oid->len, ASN1_OID ) ) != 0 )
        return( POLARSSL_ERR_X509_INVALID_NAME + ret );

    oid->p = *p;
    *p += oid->len;

    if( ( end - *p ) < 1 )
        return( POLARSSL_ERR_X509_INVALID_NAME +
                POLARSSL_ERR_ASN1_OUT_OF_DATA );

    if( **p != ASN1_BMP_STRING && **p != ASN1_UTF8_STRING      &&
        **p != ASN1_T61_STRING && **p != ASN1_PRINTABLE_STRING &&
        **p != ASN1_IA5_STRING && **p != ASN1_UNIVERSAL_STRING )
        return( POLARSSL_ERR_X509_INVALID_NAME +
                POLARSSL_ERR_ASN1_UNEXPECTED_TAG );

    val = &cur->val;
    val->tag = *(*p)++;

    if( ( ret = asn1_get_len( p, end, &val->len ) ) != 0 )
        return( POLARSSL_ERR_X509_INVALID_NAME + ret );

    val->p = *p;
    *p += val->len;

    cur->next = NULL;

    return( 0 );
}
static int x509_get_attr_type_value( unsigned char **p,
                                     const unsigned char *end,
                                     x509_name *cur )
{
    int ret;
    size_t len;
    x509_buf *oid;
    x509_buf *val;

    if( ( ret = asn1_get_tag( p, end, &len,
            ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
        return( POLARSSL_ERR_X509_INVALID_NAME + ret );

    if( ( end - *p ) < 1 )
        return( POLARSSL_ERR_X509_INVALID_NAME +
                POLARSSL_ERR_ASN1_OUT_OF_DATA );

    oid = &cur->oid;
    oid->tag = **p;

    if( ( ret = asn1_get_tag( p, end, &oid->len, ASN1_OID ) ) != 0 )
        return( POLARSSL_ERR_X509_INVALID_NAME + ret );

    oid->p = *p;
    *p += oid->len;

    if( ( end - *p ) < 1 )
        return( POLARSSL_ERR_X509_INVALID_NAME +
                POLARSSL_ERR_ASN1_OUT_OF_DATA );

    if( **p != ASN1_BMP_STRING && **p != ASN1_UTF8_STRING      &&
        **p != ASN1_T61_STRING && **p != ASN1_PRINTABLE_STRING &&
        **p != ASN1_IA5_STRING && **p != ASN1_UNIVERSAL_STRING )
        return( POLARSSL_ERR_X509_INVALID_NAME +
                POLARSSL_ERR_ASN1_UNEXPECTED_TAG );

    val = &cur->val;
    val->tag = *(*p)++;

    if( ( ret = asn1_get_len( p, end, &val->len ) ) != 0 )
        return( POLARSSL_ERR_X509_INVALID_NAME + ret );

    val->p = *p;
    *p += val->len;

    cur->next = NULL;

    return( 0 );
}