[lbry] txscript: introduce claim script
Co-authored-by: Brannon King <countprimes@gmail.com>
This commit is contained in:
Roy Lee
parent
7657419b22
commit
2b28dfa528
2 changed files with 296 additions and 0 deletions
216
txscript/claimscript.go
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216
txscript/claimscript.go
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package txscript
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import (
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"bytes"
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"fmt"
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"unicode/utf8"
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)
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const (
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// MaxClaimScriptSize is the max claim script size in bytes, not including the script pubkey part of the script.
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MaxClaimScriptSize = 8192
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// MaxClaimNameSize is the max claim name size in bytes, for all claim trie transactions.
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MaxClaimNameSize = 255
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ClaimIDLength = 160 / 8
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claimScriptVersion = 0
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)
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// These constants are used to identify a specific claim script Error.
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// The error code starts from 200, which leaves enough room between the rest
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// of script error codes (numErrorCodes)
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const (
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// ErrNotClaimScript is returned when the script does not have a ClaimScript Opcode.
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ErrNotClaimScript ErrorCode = iota + 200
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// ErrInvalidClaimNameScript is returned a claim name script does not conform to the format.
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ErrInvalidClaimNameScript
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// ErrInvalidClaimSupportScript is returned a claim support script does not conform to the format.
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ErrInvalidClaimSupportScript
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// ErrInvalidClaimUpdateScript is returned a claim update script does not conform to the format.
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ErrInvalidClaimUpdateScript
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)
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func claimScriptError(c ErrorCode, desc string) Error {
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return Error{ErrorCode: c, Description: desc}
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}
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// ClaimNameScript creates a claim name script.
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func ClaimNameScript(name string, value string) ([]byte, error) {
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return NewScriptBuilder().AddOp(OP_CLAIMNAME).AddData([]byte(name)).AddData([]byte(value)).
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AddOp(OP_2DROP).AddOp(OP_DROP).AddOp(OP_TRUE).Script()
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}
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// ClaimSupportScript creates a support claim script.
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func ClaimSupportScript(name string, claimID []byte, value []byte) ([]byte, error) {
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builder := NewScriptBuilder().AddOp(OP_SUPPORTCLAIM).AddData([]byte(name)).AddData(claimID)
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if len(value) > 0 {
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return builder.addData(value).AddOp(OP_2DROP).AddOp(OP_2DROP).AddOp(OP_TRUE).Script()
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}
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return builder.AddOp(OP_2DROP).AddOp(OP_DROP).AddOp(OP_TRUE).Script()
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}
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// ClaimUpdateScript creates an update claim script.
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func ClaimUpdateScript(name string, claimID []byte, value string) ([]byte, error) {
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return NewScriptBuilder().AddOp(OP_UPDATECLAIM).AddData([]byte(name)).AddData(claimID).AddData([]byte(value)).
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AddOp(OP_2DROP).AddOp(OP_2DROP).AddOp(OP_TRUE).Script()
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}
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// ClaimScript represents of one of the ClaimNameScript, ClaimSupportScript, and ClaimUpdateScript.
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type ClaimScript struct {
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Opcode byte
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Name []byte
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ClaimID []byte
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Value []byte
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Size int
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}
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// ExtractClaimScript exctracts the claim script from the script if it has one.
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// The returned ClaimScript is invalidated if the given script is modified.
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func ExtractClaimScript(script []byte) (*ClaimScript, error) {
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var cs ClaimScript
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tokenizer := MakeScriptTokenizer(claimScriptVersion, script)
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if !tokenizer.Next() {
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return nil, claimScriptError(ErrNotClaimScript, "not a claim script opcode")
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}
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cs.Opcode = tokenizer.Opcode()
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switch tokenizer.Opcode() {
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case OP_CLAIMNAME:
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// OP_CLAIMNAME <Name> <Value> OP_2DROP OP_DROP <P2PKH>
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if !tokenizer.Next() || len(tokenizer.Data()) > MaxClaimNameSize {
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str := fmt.Sprintf("name size %d exceeds limit %d", len(tokenizer.data), MaxClaimNameSize)
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return nil, claimScriptError(ErrInvalidClaimNameScript, str)
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}
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cs.Name = tokenizer.data
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if !tokenizer.Next() {
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return nil, claimScriptError(ErrInvalidClaimNameScript, "expect value")
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}
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cs.Value = tokenizer.Data()
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if !tokenizer.Next() || tokenizer.Opcode() != OP_2DROP ||
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!tokenizer.Next() || tokenizer.Opcode() != OP_DROP {
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str := fmt.Sprintf("expect OP_2DROP OP_DROP")
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return nil, claimScriptError(ErrInvalidClaimNameScript, str)
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}
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cs.Size = int(tokenizer.ByteIndex())
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return &cs, nil
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case OP_SUPPORTCLAIM:
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// OP_SUPPORTCLAIM <Name> <ClaimID> OP_2DROP OP_DROP <P2PKH>
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// OP_SUPPORTCLAIM <Name> <ClaimID> <Value> OP_2DROP OP_2DROP <P2PKH>
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if !tokenizer.Next() || len(tokenizer.Data()) > MaxClaimNameSize {
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str := fmt.Sprintf("name size %d exceeds limit %d", len(tokenizer.data), MaxClaimNameSize)
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return nil, claimScriptError(ErrInvalidClaimSupportScript, str)
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}
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cs.Name = tokenizer.data
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if !tokenizer.Next() || len(tokenizer.Data()) != ClaimIDLength {
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str := fmt.Sprintf("expect claim id length %d, instead of %d", ClaimIDLength, len(tokenizer.data))
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return nil, claimScriptError(ErrInvalidClaimSupportScript, str)
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}
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cs.ClaimID = tokenizer.Data()
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if !tokenizer.Next() {
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return nil, claimScriptError(ErrInvalidClaimSupportScript, "incomplete script")
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}
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switch {
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case tokenizer.Opcode() == OP_2DROP:
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// Case 1: OP_SUPPORTCLAIM <Name> <ClaimID> OP_2DROP OP_DROP <P2PKH>
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if !tokenizer.Next() || tokenizer.Opcode() != OP_DROP {
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str := fmt.Sprintf("expect OP_2DROP OP_DROP")
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return nil, claimScriptError(ErrInvalidClaimSupportScript, str)
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}
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case len(tokenizer.Data()) != 0:
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// Case 2: OP_SUPPORTCLAIM <Name> <ClaimID> <Dummy Value> OP_2DROP OP_2DROP <P2PKH>
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// (old bug: non-length size dummy value?)
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cs.Value = tokenizer.Data()
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if !tokenizer.Next() || tokenizer.Opcode() != OP_2DROP ||
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!tokenizer.Next() || tokenizer.Opcode() != OP_2DROP {
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str := fmt.Sprintf("expect OP_2DROP OP_2DROP")
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return nil, claimScriptError(ErrInvalidClaimSupportScript, str)
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}
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default:
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str := fmt.Sprintf("expect OP_2DROP OP_DROP")
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return nil, claimScriptError(ErrInvalidClaimSupportScript, str)
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}
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cs.Size = int(tokenizer.ByteIndex())
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return &cs, nil
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case OP_UPDATECLAIM:
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// OP_UPDATECLAIM <Name> <ClaimID> <Value> OP_2DROP OP_2DROP <P2PKH>
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if !tokenizer.Next() || len(tokenizer.Data()) > MaxClaimNameSize {
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str := fmt.Sprintf("name size %d exceeds limit %d", len(tokenizer.data), MaxClaimNameSize)
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return nil, claimScriptError(ErrInvalidClaimUpdateScript, str)
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}
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cs.Name = tokenizer.data
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if !tokenizer.Next() || len(tokenizer.Data()) != ClaimIDLength {
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str := fmt.Sprintf("expect claim id length %d, instead of %d", ClaimIDLength, len(tokenizer.data))
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return nil, claimScriptError(ErrInvalidClaimUpdateScript, str)
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}
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cs.ClaimID = tokenizer.Data()
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if !tokenizer.Next() {
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str := fmt.Sprintf("expect value")
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return nil, claimScriptError(ErrInvalidClaimUpdateScript, str)
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}
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cs.Value = tokenizer.Data()
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if !tokenizer.Next() || tokenizer.Opcode() != OP_2DROP ||
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!tokenizer.Next() || tokenizer.Opcode() != OP_2DROP {
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str := fmt.Sprintf("expect OP_2DROP OP_2DROP")
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return nil, claimScriptError(ErrInvalidClaimUpdateScript, str)
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}
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cs.Size = int(tokenizer.ByteIndex())
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return &cs, nil
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default:
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return nil, claimScriptError(ErrNotClaimScript, "")
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}
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}
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// StripClaimScriptPrefix strips prefixed claim script, if any.
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func StripClaimScriptPrefix(script []byte) []byte {
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cs, err := ExtractClaimScript(script)
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if err != nil {
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return script
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}
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return script[cs.Size:]
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}
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const illegalChars = "=&#:*$%?/;\\\b\n\t\r\x00"
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func AllClaimsAreSane(script []byte, enforceSoftFork bool) error {
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cs, err := ExtractClaimScript(script)
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if IsErrorCode(err, ErrNotClaimScript) {
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return nil
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}
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if err != nil {
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return err
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}
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if enforceSoftFork {
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if !utf8.Valid(cs.Name) {
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return fmt.Errorf("claim name is not valid UTF-8")
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}
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if bytes.ContainsAny(cs.Name, illegalChars) {
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return fmt.Errorf("claim name has illegal chars; it should not contain any of these: %s", illegalChars)
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}
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}
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return nil
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}
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80
txscript/claimscript_test.go
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80
txscript/claimscript_test.go
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@ -0,0 +1,80 @@
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package txscript
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import (
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"testing"
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"github.com/stretchr/testify/require"
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)
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func TestCreationParseLoopClaim(t *testing.T) {
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r := require.New(t)
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// OP_CLAIMNAME <Name> <Value> OP_2DROP OP_DROP <P2PKH>
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script, err := ClaimNameScript("tester", "value")
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r.NoError(err)
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cs, err := ExtractClaimScript(script)
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r.NoError(err)
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r.Equal(byte(OP_CLAIMNAME), cs.Opcode)
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r.Equal([]byte("tester"), cs.Name)
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r.Equal([]byte("value"), cs.Value)
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}
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func TestCreationParseLoopUpdate(t *testing.T) {
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r := require.New(t)
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claimID := []byte("12345123451234512345")
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claim, err := ClaimUpdateScript("tester", claimID, "value")
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r.NoError(err)
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cs, err := ExtractClaimScript(claim)
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r.NoError(err)
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r.Equal(byte(OP_UPDATECLAIM), cs.Opcode)
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r.Equal([]byte("tester"), cs.Name)
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r.Equal(claimID, cs.ClaimID)
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r.Equal([]byte("value"), cs.Value)
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}
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func TestCreationParseLoopSupport(t *testing.T) {
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r := require.New(t)
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claimID := []byte("12345123451234512345")
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// case 1: OP_SUPPORTCLAIM <Name> <ClaimID> OP_2DROP OP_DROP <P2PKH>
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script, err := ClaimSupportScript("tester", claimID, nil)
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r.NoError(err)
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cs, err := ExtractClaimScript(script)
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r.NoError(err)
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r.Equal(byte(OP_SUPPORTCLAIM), cs.Opcode)
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r.Equal([]byte("tester"), cs.Name)
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r.Equal(claimID, cs.ClaimID)
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r.Nil(cs.Value)
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// case 2: OP_SUPPORTCLAIM <Name> <ClaimID> <Value> OP_2DROP OP_2DROP <P2PKH>
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script, err = ClaimSupportScript("tester", claimID, []byte("value"))
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r.NoError(err)
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cs, err = ExtractClaimScript(script)
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r.NoError(err)
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r.Equal(byte(OP_SUPPORTCLAIM), cs.Opcode)
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r.Equal([]byte("tester"), cs.Name)
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r.Equal(claimID, cs.ClaimID)
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r.Equal([]byte("value"), cs.Value)
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}
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func TestInvalidChars(t *testing.T) {
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r := require.New(t)
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script, err := ClaimNameScript("tester", "value")
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r.NoError(err)
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r.NoError(AllClaimsAreSane(script, true))
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for i := range []byte(illegalChars) {
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script, err := ClaimNameScript("a"+illegalChars[i:i+1], "value")
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r.NoError(err)
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r.Error(AllClaimsAreSane(script, true))
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}
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}
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