.github/workflows/build-and-test.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         go:
-          - 1.16.x
+          - 1.18.x
           - 1.19.x
           - 1.20.x
     name: Go ${{ matrix.go }} build

builder.go

@@ -7,12 +7,12 @@ import (
 	"math/rand"
 	"mime"
 	"net/mail"
-	"net/textproto"
 	"path/filepath"
 	"reflect"
 	"time"
 
 	"github.com/jhillyerd/enmime/internal/stringutil"
+	"github.com/jhillyerd/enmime/internal/textproto"
 )
 
 // MailBuilder facilitates the easy construction of a MIME message.  Each manipulation method

detect.go

@@ -1,9 +1,9 @@
 package enmime
 
 import (
-	"net/textproto"
 	"strings"
 
+	"github.com/jhillyerd/enmime/internal/textproto"
 	"github.com/jhillyerd/enmime/mediatype"
 )
 

detect_test.go

@@ -1,10 +1,11 @@
 package enmime
 
 import (
-	"net/textproto"
 	"os"
 	"path/filepath"
 	"testing"
+
+	"github.com/jhillyerd/enmime/internal/textproto"
 )
 
 func TestDetectSinglePart(t *testing.T) {

dsn/dsn.go

@@ -3,8 +3,9 @@
 package dsn
 
 import (
-	"net/textproto"
 	"strings"
+
+	"github.com/jhillyerd/enmime/internal/textproto"
 )
 
 // Report represents delivery status report as per https://datatracker.ietf.org/doc/html/rfc6522.

dsn/parse.go

@@ -6,9 +6,9 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net/textproto"
 
 	"github.com/jhillyerd/enmime"
+	"github.com/jhillyerd/enmime/internal/textproto"
 )
 
 // ParseReport parses p as a "container" for delivery status report (per rfc6522) if p is "multipart/report".

dsn/parse_internal_test.go

@@ -1,10 +1,11 @@
 package dsn
 
 import (
-	"net/textproto"
 	"testing"
 
 	"github.com/jhillyerd/enmime"
+	"github.com/jhillyerd/enmime/internal/textproto"
+
 	"github.com/stretchr/testify/assert"
 )
 

dsn/parse_test.go

@@ -2,13 +2,14 @@ package dsn_test
 
 import (
 	"bytes"
-	"net/textproto"
 	"os"
 	"path/filepath"
 	"testing"
 
 	"github.com/jhillyerd/enmime"
 	"github.com/jhillyerd/enmime/dsn"
+	"github.com/jhillyerd/enmime/internal/textproto"
+
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )

encode.go

@@ -6,12 +6,12 @@ import (
 	"io"
 	"mime"
 	"mime/quotedprintable"
-	"net/textproto"
 	"sort"
 	"time"
 
 	"github.com/jhillyerd/enmime/internal/coding"
 	"github.com/jhillyerd/enmime/internal/stringutil"
+	"github.com/jhillyerd/enmime/internal/textproto"
 )
 
 // b64Percent determines the percent of non-ASCII characters enmime will tolerate before switching

envelope.go

@@ -5,13 +5,14 @@ import (
 	"io"
 	"mime"
 	"net/mail"
-	"net/textproto"
 	"strings"
 	"time"
 
 	"github.com/jaytaylor/html2text"
 	"github.com/jhillyerd/enmime/internal/coding"
+	"github.com/jhillyerd/enmime/internal/textproto"
 	"github.com/jhillyerd/enmime/mediatype"
+
 	"github.com/pkg/errors"
 )
 
@@ -57,7 +58,7 @@ func (e *Envelope) GetHeaderValues(name string) []string {
 		return []string{}
 	}
 
-	rawValues := (*e.header)[textproto.CanonicalMIMEHeaderKey(name)]
+	rawValues := (*e.header)[textproto.CanonicalEmailMIMEHeaderKey(name)]
 	values := make([]string, 0, len(rawValues))
 	for _, v := range rawValues {
 		values = append(values, coding.DecodeExtHeader(v))

go.mod

@@ -1,17 +1,24 @@
 module github.com/jhillyerd/enmime
 
+go 1.18
+
 require (
 	github.com/cention-sany/utf7 v0.0.0-20170124080048-26cad61bd60a
 	github.com/go-test/deep v1.0.7
 	github.com/gogs/chardet v0.0.0-20191104214054-4b6791f73a28
 	github.com/jaytaylor/html2text v0.0.0-20200412013138-3577fbdbcff7
+	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.7.0
+	golang.org/x/text v0.8.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.0 // indirect
 	github.com/mattn/go-runewidth v0.0.12 // indirect
 	github.com/olekukonko/tablewriter v0.0.5 // indirect
-	github.com/pkg/errors v0.9.1
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
 	github.com/ssor/bom v0.0.0-20170718123548-6386211fdfcf // indirect
-	github.com/stretchr/testify v1.7.0
-	golang.org/x/text v0.3.8
+	golang.org/x/net v0.8.0 // indirect
+	gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c // indirect
 )
-
-go 1.13

go.sum

@@ -25,32 +25,10 @@ github.com/ssor/bom v0.0.0-20170718123548-6386211fdfcf/go.mod h1:RJID2RhlZKId02n
 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/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
-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 h1:PxfKdU9lEEDYjdIzOtC4qFWgkU2rGHdKlKowJSMN9h0=
-golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
-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/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/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/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 v0.3.8 h1:nAL+RVCQ9uMn3vJZbV+MRnydTJFPf8qqY42YiA6MrqY=
-golang.org/x/text v0.3.8/go.mod h1:E6s5w1FMmriuDzIBO73fBruAKo1PCIq6d2Q6DHfQ8WQ=
-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/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/net v0.8.0 h1:Zrh2ngAOFYneWTAIAPethzeaQLuHwhuBkuV6ZiRnUaQ=
+golang.org/x/net v0.8.0/go.mod h1:QVkue5JL9kW//ek3r6jTKnTFis1tRmNAW2P1shuFdJc=
+golang.org/x/text v0.8.0 h1:57P1ETyNKtuIjB4SRd15iJxuhj8Gc416Y78H3qgMh68=
+golang.org/x/text v0.8.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 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 h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=

header.go

@@ -6,12 +6,13 @@ import (
 	"fmt"
 	"mime"
 	"net/mail"
-	"net/textproto"
 	"strings"
 
 	"github.com/jhillyerd/enmime/internal/coding"
 	"github.com/jhillyerd/enmime/internal/stringutil"
+	"github.com/jhillyerd/enmime/internal/textproto"
 	"github.com/jhillyerd/enmime/mediatype"
+
 	"github.com/pkg/errors"
 )
 
@@ -159,7 +160,7 @@ line:
 			// Behavior change in net/textproto package in Golang 1.20: invalid characters
 			// in header keys are no longer allowed; https://github.com/golang/go/issues/53188
 			for _, c := range s[:firstColon] {
-				if c != ' ' && !validHeaderFieldByte(c) {
+				if c != ' ' && !textproto.ValidEmailHeaderFieldByte(c) {
 					p.addError(
 						ErrorMalformedHeader, "Header name %q contains invalid character %q", s, c)
 					continue line
@@ -192,7 +193,7 @@ line:
 
 	buf.Write([]byte{'\r', '\n'})
 	tr := textproto.NewReader(bufio.NewReader(buf))
-	header, err := tr.ReadMIMEHeader()
+	header, err := tr.ReadEmailMIMEHeader()
 	return header, errors.WithStack(err)
 }
 
@@ -252,32 +253,3 @@ func quotedDisplayName(s string) string {
 func whiteSpaceRune(r rune) bool {
 	return r == ' ' || r == '\t' || r == '\r' || r == '\n'
 }
-
-// Mirror of func in net/textproto/reader.go; from go 1.20.0-rc.2
-func validHeaderFieldByte(c byte) bool {
-	// mask is a 128-bit bitmap with 1s for allowed bytes,
-	// so that the byte c can be tested with a shift and an and.
-	// If c >= 128, then 1<<c and 1<<(c-64) will both be zero,
-	// and this function will return false.
-	const mask = 0 |
-		(1<<(10)-1)<<'0' |
-		(1<<(26)-1)<<'a' |
-		(1<<(26)-1)<<'A' |
-		1<<'!' |
-		1<<'#' |
-		1<<'$' |
-		1<<'%' |
-		1<<'&' |
-		1<<'\'' |
-		1<<'*' |
-		1<<'+' |
-		1<<'-' |
-		1<<'.' |
-		1<<'^' |
-		1<<'_' |
-		1<<'`' |
-		1<<'|' |
-		1<<'~'
-	return ((uint64(1)<<c)&(mask&(1<<64-1)) |
-		(uint64(1)<<(c-64))&(mask>>64)) != 0
-}

header_test.go

@@ -3,9 +3,10 @@ package enmime
 import (
 	"bufio"
 	"net/mail"
-	"net/textproto"
 	"strings"
 	"testing"
+
+	"github.com/jhillyerd/enmime/internal/textproto"
 )
 
 // Test re-encoding to base64
@@ -250,9 +251,20 @@ func TestReadHeader(t *testing.T) {
 			correct: true,
 		},
 		{
-			label:   "equals in name",
-			input:   "name=value:text\n",
-			correct: false,
+			// all special characters of printable ASCII characters (exclude
+			// 0-9, a-z, A-Z, :, and ` (tested in next case).
+			label:   "special characters in header field",
+			input:   `X-!"#$%&'()*+,-./;<=>?@[\]^_{|}~:text` + "\n",
+			hname:   `X-!"#$%&'()*+,-./;<=>?@[\]^_{|}~`,
+			want:    "text",
+			correct: true,
+		},
+		{
+			label:   "special character (`) in header field",
+			input:   "X-`:text\n",
+			hname:   "X-`",
+			want:    "text",
+			correct: true,
 		},
 		{
 			label:   "no space before continuation",
@@ -367,9 +379,9 @@ func TestReadHeader(t *testing.T) {
 			// Check for extra headers by removing expected ones.
 			delete(header, "From")
 			delete(header, "Subject")
-			delete(header, textproto.CanonicalMIMEHeaderKey(tt.hname))
+			delete(header, textproto.CanonicalEmailMIMEHeaderKey(tt.hname))
 			for _, hname := range tt.extras {
-				delete(header, textproto.CanonicalMIMEHeaderKey(hname))
+				delete(header, textproto.CanonicalEmailMIMEHeaderKey(hname))
 			}
 			for hname := range header {
 				t.Errorf("Found unexpected header %q after parsing", hname)

inspect.go

@@ -4,9 +4,10 @@ import (
 	"bufio"
 	"bytes"
 	"io"
-	"net/textproto"
 
 	"github.com/jhillyerd/enmime/internal/coding"
+	"github.com/jhillyerd/enmime/internal/textproto"
+
 	"github.com/pkg/errors"
 )
 
@@ -49,7 +50,7 @@ func DecodeHeaders(b []byte, addtlHeaders ...string) (textproto.MIMEHeader, erro
 	headerList = append(headerList, addtlHeaders...)
 	res := map[string][]string{}
 	for _, header := range headerList {
-		h := textproto.CanonicalMIMEHeaderKey(header)
+		h := textproto.CanonicalEmailMIMEHeaderKey(header)
 		res[h] = make([]string, 0, len(headers[h]))
 		for _, value := range headers[h] {
 			res[h] = append(res[h], DecodeRFC2047(value))

inspect_test.go

@@ -5,12 +5,12 @@ import (
 	"io"
 	"io/ioutil"
 	"net/mail"
-	"net/textproto"
 	"strings"
 	"testing"
 
 	"github.com/jhillyerd/enmime"
 	"github.com/jhillyerd/enmime/internal/test"
+	"github.com/jhillyerd/enmime/internal/textproto"
 )
 
 func TestDecodeRFC2047(t *testing.T) {