initial addition of essential crypto, encoders, workflows and LLM instructions

pkg/crypto/ec/schnorr/error.go

@@ -0,0 +1,71 @@
+// Copyright (c) 2013-2017 The btcsuite developers
+// Copyright (c) 2014 Conformal Systems LLC.
+// Copyright (c) 2015-2021 The Decred developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package schnorr
+
+// ErrorKind identifies a kind of error. It has full support for errors.Is and
+// errors.As, so the caller can directly check against an error kind when
+// determining the reason for an error.
+type ErrorKind string
+
+// These constants are used to identify a specific RuleError.
+const (
+	// ErrInvalidHashLen indicates that the input hash to sign or verify is not
+	// the required length.
+	ErrInvalidHashLen = ErrorKind("ErrInvalidHashLen")
+	// ErrSecretKeyIsZero indicates an attempt was made to sign a message with
+	// a secret key that is equal to zero.
+	ErrSecretKeyIsZero  = ErrorKind("ErrSecretKeyIsZero")
+	ErrPrivateKeyIsZero = ErrSecretKeyIsZero
+	// ErrSchnorrHashValue indicates that the hash of (R || m) was too large and
+	// so a new nonce should be used.
+	ErrSchnorrHashValue = ErrorKind("ErrSchnorrHashValue")
+	// ErrPubKeyNotOnCurve indicates that a point was not on the given elliptic
+	// curve.
+	ErrPubKeyNotOnCurve = ErrorKind("ErrPubKeyNotOnCurve")
+	// ErrSigRYIsOdd indicates that the calculated Y value of R was odd.
+	ErrSigRYIsOdd = ErrorKind("ErrSigRYIsOdd")
+	// ErrSigRNotOnCurve indicates that the calculated or given point R for some
+	// signature was not on the curve.
+	ErrSigRNotOnCurve = ErrorKind("ErrSigRNotOnCurve")
+	// ErrUnequalRValues indicates that the calculated point R for some
+	// signature was not the same as the given R value for the signature.
+	ErrUnequalRValues = ErrorKind("ErrUnequalRValues")
+	// ErrSigTooShort is returned when a signature that should be a Schnorr
+	// signature is too short.
+	ErrSigTooShort = ErrorKind("ErrSigTooShort")
+	// ErrSigTooLong is returned when a signature that should be a Schnorr
+	// signature is too long.
+	ErrSigTooLong = ErrorKind("ErrSigTooLong")
+	// ErrSigRTooBig is returned when a signature has r with a value that is
+	// greater than or equal to the prime of the field underlying the group.
+	ErrSigRTooBig = ErrorKind("ErrSigRTooBig")
+	// ErrSigSTooBig is returned when a signature has s with a value that is
+	// greater than or equal to the group order.
+	ErrSigSTooBig = ErrorKind("ErrSigSTooBig")
+)
+
+// Error satisfies the error interface and prints human-readable errors.
+func (err ErrorKind) Error() string { return string(err) }
+
+// Error identifies an error related to a schnorr signature. It has full support
+// for errors.Is and errors.As, so the caller can ascertain the specific reason
+// for the error by checking the underlying error.
+type Error struct {
+	Err         error
+	Description string
+}
+
+// Error satisfies the error interface and prints human-readable errors.
+func (err Error) Error() string { return err.Description }
+
+// Unwrap returns the underlying wrapped error.
+func (err Error) Unwrap() (ee error) { return err.Err }
+
+// signatureError creates an Error given a set of arguments.
+func signatureError(kind ErrorKind, desc string) (err error) {
+	return Error{Err: kind, Description: desc}
+}