for i := v; i >= 0x80; i >>= 8 {
			length++
		}

		for ; length > 0; length-- {
			i := v >> uint((length-1)*8) & 0xff
			c.AddUint8(uint8(i))
		}
	})
}

// AddASN1BigInt appends a DER-encoded ASN.1 INTEGER.
func (b *Builder) AddASN1BigInt(n *big.Int) {
	if b.err != nil {
		return
	}

	b.AddASN1(asn1.INTEGER, func(c *Builder) {
		if n.Sign() < 0 {