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549 lines
22 KiB
Go
549 lines
22 KiB
Go
// Copyright (c) 2013-2017 The btcsuite developers
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// Copyright (c) 2015-2019 The Decred developers
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package txscript
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import (
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"fmt"
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)
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// ErrorCode identifies a kind of script error.
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type ErrorCode int
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// These constants are used to identify a specific Error.
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const (
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// ErrInternal is returned if internal consistency checks fail. In
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// practice this error should never be seen as it would mean there is an
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// error in the engine logic.
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ErrInternal ErrorCode = iota
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// ---------------------------------------
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// Failures related to improper API usage.
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// ---------------------------------------
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// ErrInvalidFlags is returned when the passed flags to NewEngine
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// contain an invalid combination.
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ErrInvalidFlags
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// ErrInvalidIndex is returned when an out-of-bounds index is passed to
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// a function.
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ErrInvalidIndex
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// ErrUnsupportedAddress is returned when a concrete type that
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// implements a btcutil.Address is not a supported type.
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ErrUnsupportedAddress
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// ErrNotMultisigScript is returned from CalcMultiSigStats when the
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// provided script is not a multisig script.
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ErrNotMultisigScript
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// ErrTooManyRequiredSigs is returned from MultiSigScript when the
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// specified number of required signatures is larger than the number of
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// provided public keys.
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ErrTooManyRequiredSigs
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// ErrTooMuchNullData is returned from NullDataScript when the length of
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// the provided data exceeds MaxDataCarrierSize.
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ErrTooMuchNullData
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// ErrUnsupportedScriptVersion is returned when an unsupported script
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// version is passed to a function which deals with script analysis.
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ErrUnsupportedScriptVersion
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// ------------------------------------------
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// Failures related to final execution state.
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// ------------------------------------------
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// ErrEarlyReturn is returned when OP_RETURN is executed in the script.
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ErrEarlyReturn
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// ErrEmptyStack is returned when the script evaluated without error,
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// but terminated with an empty top stack element.
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ErrEmptyStack
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// ErrEvalFalse is returned when the script evaluated without error but
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// terminated with a false top stack element.
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ErrEvalFalse
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// ErrScriptUnfinished is returned when CheckErrorCondition is called on
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// a script that has not finished executing.
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ErrScriptUnfinished
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// ErrScriptDone is returned when an attempt to execute an opcode is
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// made once all of them have already been executed. This can happen
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// due to things such as a second call to Execute or calling Step after
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// all opcodes have already been executed.
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ErrInvalidProgramCounter
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// -----------------------------------------------------
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// Failures related to exceeding maximum allowed limits.
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// -----------------------------------------------------
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// ErrScriptTooBig is returned if a script is larger than MaxScriptSize.
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ErrScriptTooBig
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// ErrElementTooBig is returned if the size of an element to be pushed
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// to the stack is over MaxScriptElementSize.
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ErrElementTooBig
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// ErrTooManyOperations is returned if a script has more than
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// MaxOpsPerScript opcodes that do not push data.
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ErrTooManyOperations
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// ErrStackOverflow is returned when stack and altstack combined depth
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// is over the limit.
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ErrStackOverflow
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// ErrInvalidPubKeyCount is returned when the number of public keys
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// specified for a multsig is either negative or greater than
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// MaxPubKeysPerMultiSig.
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ErrInvalidPubKeyCount
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// ErrInvalidSignatureCount is returned when the number of signatures
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// specified for a multisig is either negative or greater than the
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// number of public keys.
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ErrInvalidSignatureCount
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// ErrNumberTooBig is returned when the argument for an opcode that
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// expects numeric input is larger than the expected maximum number of
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// bytes. For the most part, opcodes that deal with stack manipulation
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// via offsets, arithmetic, numeric comparison, and boolean logic are
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// those that this applies to. However, any opcode that expects numeric
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// input may fail with this code.
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ErrNumberTooBig
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// --------------------------------------------
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// Failures related to verification operations.
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// --------------------------------------------
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// ErrVerify is returned when OP_VERIFY is encountered in a script and
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// the top item on the data stack does not evaluate to true.
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ErrVerify
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// ErrEqualVerify is returned when OP_EQUALVERIFY is encountered in a
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// script and the top item on the data stack does not evaluate to true.
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ErrEqualVerify
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// ErrNumEqualVerify is returned when OP_NUMEQUALVERIFY is encountered
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// in a script and the top item on the data stack does not evaluate to
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// true.
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ErrNumEqualVerify
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// ErrCheckSigVerify is returned when OP_CHECKSIGVERIFY is encountered
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// in a script and the top item on the data stack does not evaluate to
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// true.
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ErrCheckSigVerify
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// ErrCheckSigVerify is returned when OP_CHECKMULTISIGVERIFY is
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// encountered in a script and the top item on the data stack does not
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// evaluate to true.
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ErrCheckMultiSigVerify
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// --------------------------------------------
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// Failures related to improper use of opcodes.
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// --------------------------------------------
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// ErrDisabledOpcode is returned when a disabled opcode is encountered
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// in a script.
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ErrDisabledOpcode
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// ErrReservedOpcode is returned when an opcode marked as reserved
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// is encountered in a script.
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ErrReservedOpcode
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// ErrMalformedPush is returned when a data push opcode tries to push
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// more bytes than are left in the script.
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ErrMalformedPush
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// ErrInvalidStackOperation is returned when a stack operation is
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// attempted with a number that is invalid for the current stack size.
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ErrInvalidStackOperation
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// ErrUnbalancedConditional is returned when an OP_ELSE or OP_ENDIF is
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// encountered in a script without first having an OP_IF or OP_NOTIF or
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// the end of script is reached without encountering an OP_ENDIF when
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// an OP_IF or OP_NOTIF was previously encountered.
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ErrUnbalancedConditional
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// ---------------------------------
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// Failures related to malleability.
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// ---------------------------------
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// ErrMinimalData is returned when the ScriptVerifyMinimalData flag
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// is set and the script contains push operations that do not use
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// the minimal opcode required.
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ErrMinimalData
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// ErrInvalidSigHashType is returned when a signature hash type is not
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// one of the supported types.
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ErrInvalidSigHashType
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// ErrSigTooShort is returned when a signature that should be a
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// canonically-encoded DER signature is too short.
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ErrSigTooShort
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// ErrSigTooLong is returned when a signature that should be a
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// canonically-encoded DER signature is too long.
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ErrSigTooLong
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// ErrSigInvalidSeqID is returned when a signature that should be a
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// canonically-encoded DER signature does not have the expected ASN.1
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// sequence ID.
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ErrSigInvalidSeqID
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// ErrSigInvalidDataLen is returned a signature that should be a
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// canonically-encoded DER signature does not specify the correct number
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// of remaining bytes for the R and S portions.
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ErrSigInvalidDataLen
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// ErrSigMissingSTypeID is returned a signature that should be a
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// canonically-encoded DER signature does not provide the ASN.1 type ID
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// for S.
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ErrSigMissingSTypeID
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// ErrSigMissingSLen is returned when a signature that should be a
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// canonically-encoded DER signature does not provide the length of S.
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ErrSigMissingSLen
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// ErrSigInvalidSLen is returned a signature that should be a
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// canonically-encoded DER signature does not specify the correct number
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// of bytes for the S portion.
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ErrSigInvalidSLen
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// ErrSigInvalidRIntID is returned when a signature that should be a
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// canonically-encoded DER signature does not have the expected ASN.1
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// integer ID for R.
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ErrSigInvalidRIntID
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// ErrSigZeroRLen is returned when a signature that should be a
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// canonically-encoded DER signature has an R length of zero.
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ErrSigZeroRLen
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// ErrSigNegativeR is returned when a signature that should be a
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// canonically-encoded DER signature has a negative value for R.
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ErrSigNegativeR
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// ErrSigTooMuchRPadding is returned when a signature that should be a
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// canonically-encoded DER signature has too much padding for R.
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ErrSigTooMuchRPadding
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// ErrSigInvalidSIntID is returned when a signature that should be a
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// canonically-encoded DER signature does not have the expected ASN.1
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// integer ID for S.
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ErrSigInvalidSIntID
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// ErrSigZeroSLen is returned when a signature that should be a
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// canonically-encoded DER signature has an S length of zero.
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ErrSigZeroSLen
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// ErrSigNegativeS is returned when a signature that should be a
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// canonically-encoded DER signature has a negative value for S.
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ErrSigNegativeS
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// ErrSigTooMuchSPadding is returned when a signature that should be a
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// canonically-encoded DER signature has too much padding for S.
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ErrSigTooMuchSPadding
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// ErrSigHighS is returned when the ScriptVerifyLowS flag is set and the
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// script contains any signatures whose S values are higher than the
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// half order.
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ErrSigHighS
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// ErrNotPushOnly is returned when a script that is required to only
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// push data to the stack performs other operations. A couple of cases
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// where this applies is for a pay-to-script-hash signature script when
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// bip16 is active and when the ScriptVerifySigPushOnly flag is set.
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ErrNotPushOnly
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// ErrSigNullDummy is returned when the ScriptStrictMultiSig flag is set
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// and a multisig script has anything other than 0 for the extra dummy
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// argument.
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ErrSigNullDummy
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// ErrPubKeyType is returned when the ScriptVerifyStrictEncoding
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// flag is set and the script contains invalid public keys.
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ErrPubKeyType
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// ErrCleanStack is returned when the ScriptVerifyCleanStack flag
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// is set, and after evaluation, the stack does not contain only a
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// single element.
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ErrCleanStack
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// ErrNullFail is returned when the ScriptVerifyNullFail flag is
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// set and signatures are not empty on failed checksig or checkmultisig
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// operations.
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ErrNullFail
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// ErrWitnessMalleated is returned if ScriptVerifyWitness is set and a
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// native p2wsh program is encountered which has a non-empty sigScript.
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ErrWitnessMalleated
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// ErrWitnessMalleatedP2SH is returned if ScriptVerifyWitness if set
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// and the validation logic for nested p2sh encounters a sigScript
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// which isn't *exactyl* a datapush of the witness program.
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ErrWitnessMalleatedP2SH
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// -------------------------------
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// Failures related to soft forks.
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// -------------------------------
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// ErrDiscourageUpgradableNOPs is returned when the
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// ScriptDiscourageUpgradableNops flag is set and a NOP opcode is
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// encountered in a script.
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ErrDiscourageUpgradableNOPs
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// ErrNegativeLockTime is returned when a script contains an opcode that
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// interprets a negative lock time.
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ErrNegativeLockTime
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// ErrUnsatisfiedLockTime is returned when a script contains an opcode
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// that involves a lock time and the required lock time has not been
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// reached.
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ErrUnsatisfiedLockTime
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// ErrMinimalIf is returned if ScriptVerifyWitness is set and the
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// operand of an OP_IF/OP_NOF_IF are not either an empty vector or
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// [0x01].
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ErrMinimalIf
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// ErrDiscourageUpgradableWitnessProgram is returned if
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// ScriptVerifyWitness is set and the version of an executing witness
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// program is outside the set of currently defined witness program
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// versions.
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ErrDiscourageUpgradableWitnessProgram
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// ----------------------------------------
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// Failures related to segregated witness.
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// ----------------------------------------
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// ErrWitnessProgramEmpty is returned if ScriptVerifyWitness is set and
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// the witness stack itself is empty.
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ErrWitnessProgramEmpty
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// ErrWitnessProgramMismatch is returned if ScriptVerifyWitness is set
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// and the witness itself for a p2wkh witness program isn't *exactly* 2
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// items or if the witness for a p2wsh isn't the sha255 of the witness
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// script.
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ErrWitnessProgramMismatch
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// ErrWitnessProgramWrongLength is returned if ScriptVerifyWitness is
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// set and the length of the witness program violates the length as
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// dictated by the current witness version.
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ErrWitnessProgramWrongLength
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// ErrWitnessUnexpected is returned if ScriptVerifyWitness is set and a
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// transaction includes witness data but doesn't spend an which is a
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// witness program (nested or native).
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ErrWitnessUnexpected
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// ErrWitnessPubKeyType is returned if ScriptVerifyWitness is set and
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// the public key used in either a check-sig or check-multi-sig isn't
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// serialized in a compressed format.
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ErrWitnessPubKeyType
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// ----------------------------
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// Failures related to taproot.
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// ----------------------------
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// ErrDiscourageOpSuccess is returned if
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// ScriptVerifyDiscourageOpSuccess is active, and a OP_SUCCESS op code
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// is encountered during tapscript validation.
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ErrDiscourageOpSuccess
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// ErrDiscourageUpgradeableTaprootVersion is returned if
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// ScriptVerifyDiscourageUpgradeableTaprootVersion is active and a leaf
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// version encountered isn't the base leaf version.
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ErrDiscourageUpgradeableTaprootVersion
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// ErrTapscriptCheckMultisig is returned if a script attempts to use
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// OP_CHECKMULTISIGVERIFY or OP_CHECKMULTISIG during tapscript
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// execution.
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ErrTapscriptCheckMultisig
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// ErrDiscourageUpgradeableTaprootVersion is returned if during
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// tapscript execution, we encounter a public key that isn't 0 or 32
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// bytes.
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ErrDiscourageUpgradeablePubKeyType
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// ErrTaprootSigInvalid is returned when an invalid taproot key spend
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// signature is encountered.
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ErrTaprootSigInvalid
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// ErrTaprootMerkleProofInvalid is returned when the revealed script
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// merkle proof for a taproot spend is found to be invalid.
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ErrTaprootMerkleProofInvalid
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// ErrTaprootOutputKeyParityMismatch is returned when the control block
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// proof is valid, but the parity of the y-coordinate of the derived
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// key doesn't match the value encoded in the control block.
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ErrTaprootOutputKeyParityMismatch
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// ErrControlBlockTooSmall is returned when a parsed control block is
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// less than 33 bytes.
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ErrControlBlockTooSmall
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// ErrControlBlockTooLarge is returned when the control block is larger
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// than the largest possible proof for a merkle script tree.
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ErrControlBlockTooLarge
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// ErrControlBlockInvalidLength is returned when the control block,
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// without the public key isn't a multiple of 32.
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ErrControlBlockInvalidLength
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// ErrWitnessHasNoAnnex is returned when a caller attempts to extract
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// an annex, but the witness has no annex present.
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ErrWitnessHasNoAnnex
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// ErrInvalidTaprootSigLen is returned when taproot signature isn't 64
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// or 65 bytes.
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ErrInvalidTaprootSigLen
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// ErrTaprootPubkeyIsEmpty is returned when a signature checking op
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// code encounters an empty public key.
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ErrTaprootPubkeyIsEmpty
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// ErrTaprootMaxSigOps is returned when the number of allotted sig ops
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// is exceeded during taproot execution.
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ErrTaprootMaxSigOps
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// ErrNonConstScriptCode is returned when a signature match is found when
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// calling removeOpcodeByData in a non-segwit script.
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ErrNonConstScriptCode
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// ErrCodeSeparator is returned when OP_CODESEPARATOR is used in a
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// non-segwit script.
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ErrCodeSeparator
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// numErrorCodes is the maximum error code number used in tests. This
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// entry MUST be the last entry in the enum.
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numErrorCodes
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)
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// Map of ErrorCode values back to their constant names for pretty printing.
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var errorCodeStrings = map[ErrorCode]string{
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ErrInternal: "ErrInternal",
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ErrInvalidFlags: "ErrInvalidFlags",
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ErrInvalidIndex: "ErrInvalidIndex",
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ErrUnsupportedAddress: "ErrUnsupportedAddress",
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ErrNotMultisigScript: "ErrNotMultisigScript",
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ErrTooManyRequiredSigs: "ErrTooManyRequiredSigs",
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ErrTooMuchNullData: "ErrTooMuchNullData",
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ErrUnsupportedScriptVersion: "ErrUnsupportedScriptVersion",
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ErrEarlyReturn: "ErrEarlyReturn",
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ErrEmptyStack: "ErrEmptyStack",
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ErrEvalFalse: "ErrEvalFalse",
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ErrScriptUnfinished: "ErrScriptUnfinished",
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ErrInvalidProgramCounter: "ErrInvalidProgramCounter",
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ErrScriptTooBig: "ErrScriptTooBig",
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ErrElementTooBig: "ErrElementTooBig",
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ErrTooManyOperations: "ErrTooManyOperations",
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ErrStackOverflow: "ErrStackOverflow",
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ErrInvalidPubKeyCount: "ErrInvalidPubKeyCount",
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ErrInvalidSignatureCount: "ErrInvalidSignatureCount",
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ErrNumberTooBig: "ErrNumberTooBig",
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ErrVerify: "ErrVerify",
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ErrEqualVerify: "ErrEqualVerify",
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ErrNumEqualVerify: "ErrNumEqualVerify",
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ErrCheckSigVerify: "ErrCheckSigVerify",
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ErrCheckMultiSigVerify: "ErrCheckMultiSigVerify",
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ErrDisabledOpcode: "ErrDisabledOpcode",
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ErrReservedOpcode: "ErrReservedOpcode",
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ErrMalformedPush: "ErrMalformedPush",
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ErrInvalidStackOperation: "ErrInvalidStackOperation",
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ErrUnbalancedConditional: "ErrUnbalancedConditional",
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ErrMinimalData: "ErrMinimalData",
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ErrInvalidSigHashType: "ErrInvalidSigHashType",
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ErrSigTooShort: "ErrSigTooShort",
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ErrSigTooLong: "ErrSigTooLong",
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ErrSigInvalidSeqID: "ErrSigInvalidSeqID",
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ErrSigInvalidDataLen: "ErrSigInvalidDataLen",
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ErrSigMissingSTypeID: "ErrSigMissingSTypeID",
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ErrSigMissingSLen: "ErrSigMissingSLen",
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ErrSigInvalidSLen: "ErrSigInvalidSLen",
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ErrSigInvalidRIntID: "ErrSigInvalidRIntID",
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ErrSigZeroRLen: "ErrSigZeroRLen",
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ErrSigNegativeR: "ErrSigNegativeR",
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ErrSigTooMuchRPadding: "ErrSigTooMuchRPadding",
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ErrSigInvalidSIntID: "ErrSigInvalidSIntID",
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ErrSigZeroSLen: "ErrSigZeroSLen",
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ErrSigNegativeS: "ErrSigNegativeS",
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ErrSigTooMuchSPadding: "ErrSigTooMuchSPadding",
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ErrSigHighS: "ErrSigHighS",
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ErrNotPushOnly: "ErrNotPushOnly",
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ErrSigNullDummy: "ErrSigNullDummy",
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ErrPubKeyType: "ErrPubKeyType",
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ErrCleanStack: "ErrCleanStack",
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ErrNullFail: "ErrNullFail",
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ErrDiscourageUpgradableNOPs: "ErrDiscourageUpgradableNOPs",
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ErrNegativeLockTime: "ErrNegativeLockTime",
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ErrUnsatisfiedLockTime: "ErrUnsatisfiedLockTime",
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ErrWitnessProgramEmpty: "ErrWitnessProgramEmpty",
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ErrWitnessProgramMismatch: "ErrWitnessProgramMismatch",
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ErrWitnessProgramWrongLength: "ErrWitnessProgramWrongLength",
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ErrWitnessMalleated: "ErrWitnessMalleated",
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ErrWitnessMalleatedP2SH: "ErrWitnessMalleatedP2SH",
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ErrWitnessUnexpected: "ErrWitnessUnexpected",
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ErrMinimalIf: "ErrMinimalIf",
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ErrWitnessPubKeyType: "ErrWitnessPubKeyType",
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ErrDiscourageUpgradableWitnessProgram: "ErrDiscourageUpgradableWitnessProgram",
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ErrDiscourageOpSuccess: "ErrDiscourageOpSuccess",
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ErrDiscourageUpgradeableTaprootVersion: "ErrDiscourageUpgradeableTaprootVersion",
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ErrTapscriptCheckMultisig: "ErrTapscriptCheckMultisig",
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ErrDiscourageUpgradeablePubKeyType: "ErrDiscourageUpgradeablePubKeyType",
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ErrTaprootSigInvalid: "ErrTaprootSigInvalid",
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ErrTaprootMerkleProofInvalid: "ErrTaprootMerkleProofInvalid",
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ErrTaprootOutputKeyParityMismatch: "ErrTaprootOutputKeyParityMismatch",
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ErrControlBlockTooSmall: "ErrControlBlockTooSmall",
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ErrControlBlockTooLarge: "ErrControlBlockTooLarge",
|
|
ErrControlBlockInvalidLength: "ErrControlBlockInvalidLength",
|
|
ErrWitnessHasNoAnnex: "ErrWitnessHasNoAnnex",
|
|
ErrInvalidTaprootSigLen: "ErrInvalidTaprootSigLen",
|
|
ErrTaprootPubkeyIsEmpty: "ErrTaprootPubkeyIsEmpty",
|
|
ErrTaprootMaxSigOps: "ErrTaprootMaxSigOps",
|
|
ErrNonConstScriptCode: "ErrNonConstScriptCode",
|
|
ErrCodeSeparator: "ErrCodeSeparator",
|
|
}
|
|
|
|
// String returns the ErrorCode as a human-readable name.
|
|
func (e ErrorCode) String() string {
|
|
if s := errorCodeStrings[e]; s != "" {
|
|
return s
|
|
}
|
|
return fmt.Sprintf("Unknown ErrorCode (%d)", int(e))
|
|
}
|
|
|
|
// Error identifies a script-related error. It is used to indicate three
|
|
// classes of errors:
|
|
// 1. Script execution failures due to violating one of the many requirements
|
|
// imposed by the script engine or evaluating to false
|
|
// 2. Improper API usage by callers
|
|
// 3. Internal consistency check failures
|
|
//
|
|
// The caller can use type assertions on the returned errors to access the
|
|
// ErrorCode field to ascertain the specific reason for the error. As an
|
|
// additional convenience, the caller may make use of the IsErrorCode function
|
|
// to check for a specific error code.
|
|
type Error struct {
|
|
ErrorCode ErrorCode
|
|
Description string
|
|
}
|
|
|
|
// Error satisfies the error interface and prints human-readable errors.
|
|
func (e Error) Error() string {
|
|
return e.Description
|
|
}
|
|
|
|
// scriptError creates an Error given a set of arguments.
|
|
func scriptError(c ErrorCode, desc string) Error {
|
|
return Error{ErrorCode: c, Description: desc}
|
|
}
|
|
|
|
// IsErrorCode returns whether or not the provided error is a script error with
|
|
// the provided error code.
|
|
func IsErrorCode(err error, c ErrorCode) bool {
|
|
serr, ok := err.(Error)
|
|
return ok && serr.ErrorCode == c
|
|
}
|