Add support for VM airdrop virtual instruction

Author: Jeff Yanta

pkg/solana/cvm/types_message.go

@@ -49,6 +49,30 @@ func GetCompactWithdrawMessage(args *GetCompactWithdrawMessageArgs) CompactMessa
 	return hashMessage(message)
 }
 
+type GetCompactAirdropMessageArgs struct {
+	Source       ed25519.PublicKey
+	Destinations []ed25519.PublicKey
+	Amount       uint64
+	NonceAddress ed25519.PublicKey
+	NonceValue   Hash
+}
+
+func GetCompactAirdropMessage(args *GetCompactAirdropMessageArgs) CompactMessage {
+	amountBytes := make([]byte, 8)
+	binary.LittleEndian.PutUint64(amountBytes, args.Amount)
+
+	var message Message
+	message = append(message, []byte("airdrop")...)
+	message = append(message, args.Source...)
+	message = append(message, args.NonceAddress...)
+	message = append(message, args.NonceValue[:]...)
+	message = append(message, amountBytes...)
+	for _, destination := range args.Destinations {
+		message = append(message, destination...)
+	}
+	return hashMessage(message)
+}
+
 func hashMessage(msg Message) CompactMessage {
 	h := sha256.New()
 	h.Write(msg)

pkg/solana/cvm/types_opcode.go

@@ -14,6 +14,8 @@ const (
 	OpcodeExternalRelay    Opcode = 20
 
 	OpcodeConditionalTransfer Opcode = 12
+
+	OpcodeAirdrop Opcode = 30
 )
 
 func putOpcode(dst []byte, v Opcode, offset *int) {

pkg/solana/cvm/virtual_instructions_airdrop.go

@@ -0,0 +1,28 @@
+package cvm
+
+const (
+	AirdropVirtrualInstructionDataSize = (SignatureSize + // signature
+		8 + // amount
+		1) // count
+)
+
+type AirdropVirtualInstructionArgs struct {
+	Amount    uint64
+	Count     uint8
+	Signature Signature
+}
+
+func NewAirdropVirtualInstruction(
+	args *AirdropVirtualInstructionArgs,
+) VirtualInstruction {
+	var offset int
+	data := make([]byte, AirdropVirtrualInstructionDataSize)
+	putSignature(data, args.Signature, &offset)
+	putUint64(data, args.Amount, &offset)
+	putUint8(data, args.Count, &offset)
+
+	return VirtualInstruction{
+		Opcode: OpcodeAirdrop,
+		Data:   data,
+	}
+}