Result type

errors.go

@@ -9,21 +9,26 @@ type TokenError struct {
 	e error
 }
 
-func (e *TokenError) Error() string {
+func newTokenError(e error) TokenError {
+	return TokenError{e}
+}
+
+func (e TokenError) Error() string {
 	return e.e.Error()
 }
 
-func (_ *TokenError) Is(e error) bool {
-	_, ok := e.(*TokenError)
-	return ok
+func (_ TokenError) Is(e error) bool {
+	_, ok1 := e.(TokenError)
+	_, ok2 := e.(*TokenError)
+	return ok1 || ok2
 }
 
-func (e *TokenError) Unwrap() error {
+func (e TokenError) Unwrap() error {
 	return e.e
 }
 
-func (e *TokenError) wrapWith(msg string) *TokenError {
-	return &TokenError{fmt.Errorf("%s: %w", msg, e)}
+func (e TokenError) wrapWith(msg string) TokenError {
+	return TokenError{fmt.Errorf("%s: %w", msg, e)}
 }
 
 // Any error which is the result of a rule failure (distinct from a TokenError)
@@ -34,16 +39,21 @@ type RuleError struct {
 	e error
 }
 
-func (e *RuleError) Error() string {
+func newRuleError(e error) RuleError {
+	return RuleError{e}
+}
+
+func (e RuleError) Error() string {
 	return e.e.Error()
 }
 
-func (_ *RuleError) Is(e error) bool {
-	_, ok := e.(*RuleError)
-	return ok
+func (_ RuleError) Is(e error) bool {
+	_, ok1 := e.(RuleError)
+	_, ok2 := e.(*RuleError)
+	return ok1 || ok2
 }
 
-func (e *RuleError) Unwrap() error {
+func (e RuleError) Unwrap() error {
 	return e.e
 }
 
@@ -55,32 +65,32 @@ func errorSeedLength(expected, given int) error {
 	return fmt.Errorf("seed length incorrect (%d), expected %d", given, expected)
 }
 
-func errorMessageParts(given int) *TokenError {
-	return &TokenError{fmt.Errorf("invalid number of message parts in token (%d)", given)}
+func errorMessageParts(given int) TokenError {
+	return newTokenError(fmt.Errorf("invalid number of message parts in token (%d)", given))
 }
 
-func errorMessageHeader(expected Protocol, givenHeader string) *TokenError {
-	return &TokenError{fmt.Errorf("message header `%s' is not valid, expected `%s'", givenHeader, expected.Header())}
+func errorMessageHeader(expected Protocol, givenHeader string) TokenError {
+	return newTokenError(fmt.Errorf("message header `%s' is not valid, expected `%s'", givenHeader, expected.Header()))
 }
 
-func errorMessageHeaderDecrypt(expected Protocol, givenHeader string) *TokenError {
+func errorMessageHeaderDecrypt(expected Protocol, givenHeader string) TokenError {
 	return errorMessageHeader(expected, givenHeader).wrapWith("cannot decrypt message")
 }
 
-func errorMessageHeaderVerify(expected Protocol, givenHeader string) *TokenError {
+func errorMessageHeaderVerify(expected Protocol, givenHeader string) TokenError {
 	return errorMessageHeader(expected, givenHeader).wrapWith("cannot verify message")
 }
 
 var unsupportedPasetoVersion = fmt.Errorf("unsupported PASETO version")
 var unsupportedPasetoPurpose = fmt.Errorf("unsupported PASETO purpose")
 var unsupportedPayload = fmt.Errorf("unsupported payload")
 
-var errorPayloadShort = &TokenError{fmt.Errorf("payload is not long enough to be a valid PASETO message")}
-var errorBadSignature = &TokenError{fmt.Errorf("bad signature")}
-var errorBadMAC = &TokenError{fmt.Errorf("bad message authentication code")}
+var errorPayloadShort = newTokenError(fmt.Errorf("payload is not long enough to be a valid PASETO message"))
+var errorBadSignature = newTokenError(fmt.Errorf("bad signature"))
+var errorBadMAC = newTokenError(fmt.Errorf("bad message authentication code"))
 
 var errorKeyInvalid = fmt.Errorf("key was not valid")
 
-func errorDecrypt(err error) *TokenError {
-	return (&TokenError{err}).wrapWith("the message could not be decrypted")
+func errorDecrypt(err error) TokenError {
+	return newTokenError(err).wrapWith("the message could not be decrypted")
 }

go.mod

@@ -3,6 +3,7 @@ module aidanwoods.dev/go-paseto
 go 1.18
 
 require (
+	aidanwoods.dev/go-result v0.0.0-20230310133209-26c34aabd0c7
 	github.com/stretchr/testify v1.7.0
 	golang.org/x/crypto v0.7.0
 )

go.sum

@@ -1,3 +1,5 @@
+aidanwoods.dev/go-result v0.0.0-20230310133209-26c34aabd0c7 h1:bVUDSxup1h+a2DenqxeTWRschTdSMmo1Cy5/LxnzCtc=
+aidanwoods.dev/go-result v0.0.0-20230310133209-26c34aabd0c7/go.mod h1:yridkWghM7AXSFA6wzx0IbsurIm1Lhuro3rYef8FBHM=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -6,43 +8,10 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/crypto v0.7.0 h1:AvwMYaRytfdeVt3u6mLaxYtErKYjxA2OXjJ1HHq6t3A=
 golang.org/x/crypto v0.7.0/go.mod h1:pYwdfH91IfpZVANVyUOhSIPZaFoJGxTFbZhFTx+dXZU=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
-golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
-golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
-golang.org/x/net v0.8.0/go.mod h1:QVkue5JL9kW//ek3r6jTKnTFis1tRmNAW2P1shuFdJc=
-golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
-golang.org/x/term v0.6.0/go.mod h1:m6U89DPEgQRMq3DNkDClhWw02AUbt2daBVO4cn4Hv9U=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
-golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
-golang.org/x/text v0.8.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
-golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
-golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
-golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
-golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/encoding/base64.go

@@ -4,6 +4,8 @@ import (
 	"encoding/base64"
 	"errors"
 	"strings"
+
+	t "aidanwoods.dev/go-result"
 )
 
 var b64 = base64.RawURLEncoding.Strict()
@@ -14,12 +16,12 @@ func Encode(bytes []byte) string {
 }
 
 // Decode Standard decoding for Paseto is URL safe base64 with no padding
-func Decode(encoded string) ([]byte, error) {
+func Decode(encoded string) t.Result[[]byte] {
 	// From: https://pkg.go.dev/encoding/base64#Encoding.Strict
 	// Note that the input is still malleable, as new line characters (CR and LF) are still ignored.
 	if strings.ContainsAny(encoded, "\n\r") {
-		return nil, errors.New("Input may not contain new lines")
+		return t.Err[[]byte](errors.New("Input may not contain new lines"))
 	}
 
-	return b64.DecodeString(encoded)
+	return t.NewResult(b64.DecodeString(encoded))
 }

internal/encoding/hex.go

@@ -0,0 +1,17 @@
+package encoding
+
+import (
+	"encoding/hex"
+
+	t "aidanwoods.dev/go-result"
+)
+
+// Encode hex
+func HexEncode(bytes []byte) string {
+	return hex.EncodeToString(bytes)
+}
+
+// Decode hex
+func HexDecode(encoded string) t.Result[[]byte] {
+	return t.NewResult(hex.DecodeString(encoded))
+}

internal/encoding/paseto.go

@@ -3,25 +3,25 @@ package encoding
 import (
 	"bytes"
 	"encoding/binary"
+
+	t "aidanwoods.dev/go-result"
 )
 
 // Pae Pre Auth Encode
 func Pae(pieces ...[]byte) []byte {
 	buffer := &bytes.Buffer{}
 
 	// MSB should be zero
-	if err := binary.Write(buffer, binary.LittleEndian, int64(len(pieces))); err != nil {
-		panic("Cannot write to buffer")
-	}
+	t.NewVoidResult(binary.Write(buffer, binary.LittleEndian, int64(len(pieces)))).
+		Expect("writing to buffer should not fail")
 
 	for i := range pieces {
 		// MSB should be zero
-		if err := binary.Write(buffer, binary.LittleEndian, int64(len(pieces[i]))); err != nil {
-			panic("Cannot write to buffer")
-		}
-		if _, err := buffer.Write(pieces[i]); err != nil {
-			panic("Cannot write to buffer")
-		}
+		t.NewVoidResult(binary.Write(buffer, binary.LittleEndian, int64(len(pieces[i])))).
+			Expect("writing to buffer should not fail")
+
+		t.NewResult(buffer.Write(pieces[i])).
+			Expect("writing to buffer should not fail")
 	}
 
 	return buffer.Bytes()

internal/hashing/hashing.go

@@ -1,23 +1,17 @@
 package hashing
 
 import (
-	"hash"
-
+	t "aidanwoods.dev/go-result"
 	"golang.org/x/crypto/blake2b"
 )
 
 // GenericHash The same as crypto_generichash as referred to in the Paseto spec
 func GenericHash(in, out, key []byte) {
-	var blake hash.Hash
-	var err error
-
-	if blake, err = blake2b.New(len(out), key); err != nil {
-		panic(err)
-	}
+	blake := t.NewResult(blake2b.New(len(out), key)).
+		Expect("blake2 hasher construction should be provided with valid length inputs")
 
-	if _, err = blake.Write(in); err != nil {
-		panic(err)
-	}
+	t.NewResult(blake.Write(in)).
+		Expect("writing into hasher should not fail")
 
 	copy(out, blake.Sum(nil))
 }

internal/random/random.go

@@ -3,15 +3,13 @@ package random
 import (
 	"crypto/rand"
 	"io"
+
+	t "aidanwoods.dev/go-result"
 )
 
 // FillBytes fills out with random bytes from the OS CSPRNG, or panics
 func FillBytes(out []byte) {
-	_, err := io.ReadFull(rand.Reader, out[:])
-
-	if err != nil {
-		panic("CSPRNG failure")
-	}
+	t.NewResult(io.ReadFull(rand.Reader, out[:])).Expect("CSPRNG failure")
 }
 
 // UseProvidedOrFillBytes will fill `out' with unitTestNonce, provided it is