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-rw-r--r--src/net/mail/message.go838
1 files changed, 838 insertions, 0 deletions
diff --git a/src/net/mail/message.go b/src/net/mail/message.go
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+++ b/src/net/mail/message.go
@@ -0,0 +1,838 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package mail implements parsing of mail messages.
+
+For the most part, this package follows the syntax as specified by RFC 5322 and
+extended by RFC 6532.
+Notable divergences:
+ * Obsolete address formats are not parsed, including addresses with
+ embedded route information.
+ * The full range of spacing (the CFWS syntax element) is not supported,
+ such as breaking addresses across lines.
+ * No unicode normalization is performed.
+ * The special characters ()[]:;@\, are allowed to appear unquoted in names.
+*/
+package mail
+
+import (
+ "bufio"
+ "errors"
+ "fmt"
+ "io"
+ "log"
+ "mime"
+ "net/textproto"
+ "strings"
+ "sync"
+ "time"
+ "unicode/utf8"
+)
+
+var debug = debugT(false)
+
+type debugT bool
+
+func (d debugT) Printf(format string, args ...interface{}) {
+ if d {
+ log.Printf(format, args...)
+ }
+}
+
+// A Message represents a parsed mail message.
+type Message struct {
+ Header Header
+ Body io.Reader
+}
+
+// ReadMessage reads a message from r.
+// The headers are parsed, and the body of the message will be available
+// for reading from msg.Body.
+func ReadMessage(r io.Reader) (msg *Message, err error) {
+ tp := textproto.NewReader(bufio.NewReader(r))
+
+ hdr, err := tp.ReadMIMEHeader()
+ if err != nil {
+ return nil, err
+ }
+
+ return &Message{
+ Header: Header(hdr),
+ Body: tp.R,
+ }, nil
+}
+
+// Layouts suitable for passing to time.Parse.
+// These are tried in order.
+var (
+ dateLayoutsBuildOnce sync.Once
+ dateLayouts []string
+)
+
+func buildDateLayouts() {
+ // Generate layouts based on RFC 5322, section 3.3.
+
+ dows := [...]string{"", "Mon, "} // day-of-week
+ days := [...]string{"2", "02"} // day = 1*2DIGIT
+ years := [...]string{"2006", "06"} // year = 4*DIGIT / 2*DIGIT
+ seconds := [...]string{":05", ""} // second
+ // "-0700 (MST)" is not in RFC 5322, but is common.
+ zones := [...]string{"-0700", "MST"} // zone = (("+" / "-") 4DIGIT) / "GMT" / ...
+
+ for _, dow := range dows {
+ for _, day := range days {
+ for _, year := range years {
+ for _, second := range seconds {
+ for _, zone := range zones {
+ s := dow + day + " Jan " + year + " 15:04" + second + " " + zone
+ dateLayouts = append(dateLayouts, s)
+ }
+ }
+ }
+ }
+ }
+}
+
+// ParseDate parses an RFC 5322 date string.
+func ParseDate(date string) (time.Time, error) {
+ dateLayoutsBuildOnce.Do(buildDateLayouts)
+ // CR and LF must match and are tolerated anywhere in the date field.
+ date = strings.ReplaceAll(date, "\r\n", "")
+ if strings.Index(date, "\r") != -1 {
+ return time.Time{}, errors.New("mail: header has a CR without LF")
+ }
+ // Re-using some addrParser methods which support obsolete text, i.e. non-printable ASCII
+ p := addrParser{date, nil}
+ p.skipSpace()
+
+ // RFC 5322: zone = (FWS ( "+" / "-" ) 4DIGIT) / obs-zone
+ // zone length is always 5 chars unless obsolete (obs-zone)
+ if ind := strings.IndexAny(p.s, "+-"); ind != -1 && len(p.s) >= ind+5 {
+ date = p.s[:ind+5]
+ p.s = p.s[ind+5:]
+ } else {
+ ind := strings.Index(p.s, "T")
+ if ind == 0 {
+ // In this case we have the following date formats:
+ // * Thu, 20 Nov 1997 09:55:06 MDT
+ // * Thu, 20 Nov 1997 09:55:06 MDT (MDT)
+ // * Thu, 20 Nov 1997 09:55:06 MDT (This comment)
+ ind = strings.Index(p.s[1:], "T")
+ if ind != -1 {
+ ind++
+ }
+ }
+
+ if ind != -1 && len(p.s) >= ind+5 {
+ // The last letter T of the obsolete time zone is checked when no standard time zone is found.
+ // If T is misplaced, the date to parse is garbage.
+ date = p.s[:ind+1]
+ p.s = p.s[ind+1:]
+ }
+ }
+ if !p.skipCFWS() {
+ return time.Time{}, errors.New("mail: misformatted parenthetical comment")
+ }
+ for _, layout := range dateLayouts {
+ t, err := time.Parse(layout, date)
+ if err == nil {
+ return t, nil
+ }
+ }
+ return time.Time{}, errors.New("mail: header could not be parsed")
+}
+
+// A Header represents the key-value pairs in a mail message header.
+type Header map[string][]string
+
+// Get gets the first value associated with the given key.
+// It is case insensitive; CanonicalMIMEHeaderKey is used
+// to canonicalize the provided key.
+// If there are no values associated with the key, Get returns "".
+// To access multiple values of a key, or to use non-canonical keys,
+// access the map directly.
+func (h Header) Get(key string) string {
+ return textproto.MIMEHeader(h).Get(key)
+}
+
+var ErrHeaderNotPresent = errors.New("mail: header not in message")
+
+// Date parses the Date header field.
+func (h Header) Date() (time.Time, error) {
+ hdr := h.Get("Date")
+ if hdr == "" {
+ return time.Time{}, ErrHeaderNotPresent
+ }
+ return ParseDate(hdr)
+}
+
+// AddressList parses the named header field as a list of addresses.
+func (h Header) AddressList(key string) ([]*Address, error) {
+ hdr := h.Get(key)
+ if hdr == "" {
+ return nil, ErrHeaderNotPresent
+ }
+ return ParseAddressList(hdr)
+}
+
+// Address represents a single mail address.
+// An address such as "Barry Gibbs <bg@example.com>" is represented
+// as Address{Name: "Barry Gibbs", Address: "bg@example.com"}.
+type Address struct {
+ Name string // Proper name; may be empty.
+ Address string // user@domain
+}
+
+// ParseAddress parses a single RFC 5322 address, e.g. "Barry Gibbs <bg@example.com>"
+func ParseAddress(address string) (*Address, error) {
+ return (&addrParser{s: address}).parseSingleAddress()
+}
+
+// ParseAddressList parses the given string as a list of addresses.
+func ParseAddressList(list string) ([]*Address, error) {
+ return (&addrParser{s: list}).parseAddressList()
+}
+
+// An AddressParser is an RFC 5322 address parser.
+type AddressParser struct {
+ // WordDecoder optionally specifies a decoder for RFC 2047 encoded-words.
+ WordDecoder *mime.WordDecoder
+}
+
+// Parse parses a single RFC 5322 address of the
+// form "Gogh Fir <gf@example.com>" or "foo@example.com".
+func (p *AddressParser) Parse(address string) (*Address, error) {
+ return (&addrParser{s: address, dec: p.WordDecoder}).parseSingleAddress()
+}
+
+// ParseList parses the given string as a list of comma-separated addresses
+// of the form "Gogh Fir <gf@example.com>" or "foo@example.com".
+func (p *AddressParser) ParseList(list string) ([]*Address, error) {
+ return (&addrParser{s: list, dec: p.WordDecoder}).parseAddressList()
+}
+
+// String formats the address as a valid RFC 5322 address.
+// If the address's name contains non-ASCII characters
+// the name will be rendered according to RFC 2047.
+func (a *Address) String() string {
+ // Format address local@domain
+ at := strings.LastIndex(a.Address, "@")
+ var local, domain string
+ if at < 0 {
+ // This is a malformed address ("@" is required in addr-spec);
+ // treat the whole address as local-part.
+ local = a.Address
+ } else {
+ local, domain = a.Address[:at], a.Address[at+1:]
+ }
+
+ // Add quotes if needed
+ quoteLocal := false
+ for i, r := range local {
+ if isAtext(r, false, false) {
+ continue
+ }
+ if r == '.' {
+ // Dots are okay if they are surrounded by atext.
+ // We only need to check that the previous byte is
+ // not a dot, and this isn't the end of the string.
+ if i > 0 && local[i-1] != '.' && i < len(local)-1 {
+ continue
+ }
+ }
+ quoteLocal = true
+ break
+ }
+ if quoteLocal {
+ local = quoteString(local)
+
+ }
+
+ s := "<" + local + "@" + domain + ">"
+
+ if a.Name == "" {
+ return s
+ }
+
+ // If every character is printable ASCII, quoting is simple.
+ allPrintable := true
+ for _, r := range a.Name {
+ // isWSP here should actually be isFWS,
+ // but we don't support folding yet.
+ if !isVchar(r) && !isWSP(r) || isMultibyte(r) {
+ allPrintable = false
+ break
+ }
+ }
+ if allPrintable {
+ return quoteString(a.Name) + " " + s
+ }
+
+ // Text in an encoded-word in a display-name must not contain certain
+ // characters like quotes or parentheses (see RFC 2047 section 5.3).
+ // When this is the case encode the name using base64 encoding.
+ if strings.ContainsAny(a.Name, "\"#$%&'(),.:;<>@[]^`{|}~") {
+ return mime.BEncoding.Encode("utf-8", a.Name) + " " + s
+ }
+ return mime.QEncoding.Encode("utf-8", a.Name) + " " + s
+}
+
+type addrParser struct {
+ s string
+ dec *mime.WordDecoder // may be nil
+}
+
+func (p *addrParser) parseAddressList() ([]*Address, error) {
+ var list []*Address
+ for {
+ p.skipSpace()
+
+ // allow skipping empty entries (RFC5322 obs-addr-list)
+ if p.consume(',') {
+ continue
+ }
+
+ addrs, err := p.parseAddress(true)
+ if err != nil {
+ return nil, err
+ }
+ list = append(list, addrs...)
+
+ if !p.skipCFWS() {
+ return nil, errors.New("mail: misformatted parenthetical comment")
+ }
+ if p.empty() {
+ break
+ }
+ if p.peek() != ',' {
+ return nil, errors.New("mail: expected comma")
+ }
+
+ // Skip empty entries for obs-addr-list.
+ for p.consume(',') {
+ p.skipSpace()
+ }
+ if p.empty() {
+ break
+ }
+ }
+ return list, nil
+}
+
+func (p *addrParser) parseSingleAddress() (*Address, error) {
+ addrs, err := p.parseAddress(true)
+ if err != nil {
+ return nil, err
+ }
+ if !p.skipCFWS() {
+ return nil, errors.New("mail: misformatted parenthetical comment")
+ }
+ if !p.empty() {
+ return nil, fmt.Errorf("mail: expected single address, got %q", p.s)
+ }
+ if len(addrs) == 0 {
+ return nil, errors.New("mail: empty group")
+ }
+ if len(addrs) > 1 {
+ return nil, errors.New("mail: group with multiple addresses")
+ }
+ return addrs[0], nil
+}
+
+// parseAddress parses a single RFC 5322 address at the start of p.
+func (p *addrParser) parseAddress(handleGroup bool) ([]*Address, error) {
+ debug.Printf("parseAddress: %q", p.s)
+ p.skipSpace()
+ if p.empty() {
+ return nil, errors.New("mail: no address")
+ }
+
+ // address = mailbox / group
+ // mailbox = name-addr / addr-spec
+ // group = display-name ":" [group-list] ";" [CFWS]
+
+ // addr-spec has a more restricted grammar than name-addr,
+ // so try parsing it first, and fallback to name-addr.
+ // TODO(dsymonds): Is this really correct?
+ spec, err := p.consumeAddrSpec()
+ if err == nil {
+ var displayName string
+ p.skipSpace()
+ if !p.empty() && p.peek() == '(' {
+ displayName, err = p.consumeDisplayNameComment()
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ return []*Address{{
+ Name: displayName,
+ Address: spec,
+ }}, err
+ }
+ debug.Printf("parseAddress: not an addr-spec: %v", err)
+ debug.Printf("parseAddress: state is now %q", p.s)
+
+ // display-name
+ var displayName string
+ if p.peek() != '<' {
+ displayName, err = p.consumePhrase()
+ if err != nil {
+ return nil, err
+ }
+ }
+ debug.Printf("parseAddress: displayName=%q", displayName)
+
+ p.skipSpace()
+ if handleGroup {
+ if p.consume(':') {
+ return p.consumeGroupList()
+ }
+ }
+ // angle-addr = "<" addr-spec ">"
+ if !p.consume('<') {
+ atext := true
+ for _, r := range displayName {
+ if !isAtext(r, true, false) {
+ atext = false
+ break
+ }
+ }
+ if atext {
+ // The input is like "foo.bar"; it's possible the input
+ // meant to be "foo.bar@domain", or "foo.bar <...>".
+ return nil, errors.New("mail: missing '@' or angle-addr")
+ }
+ // The input is like "Full Name", which couldn't possibly be a
+ // valid email address if followed by "@domain"; the input
+ // likely meant to be "Full Name <...>".
+ return nil, errors.New("mail: no angle-addr")
+ }
+ spec, err = p.consumeAddrSpec()
+ if err != nil {
+ return nil, err
+ }
+ if !p.consume('>') {
+ return nil, errors.New("mail: unclosed angle-addr")
+ }
+ debug.Printf("parseAddress: spec=%q", spec)
+
+ return []*Address{{
+ Name: displayName,
+ Address: spec,
+ }}, nil
+}
+
+func (p *addrParser) consumeGroupList() ([]*Address, error) {
+ var group []*Address
+ // handle empty group.
+ p.skipSpace()
+ if p.consume(';') {
+ p.skipCFWS()
+ return group, nil
+ }
+
+ for {
+ p.skipSpace()
+ // embedded groups not allowed.
+ addrs, err := p.parseAddress(false)
+ if err != nil {
+ return nil, err
+ }
+ group = append(group, addrs...)
+
+ if !p.skipCFWS() {
+ return nil, errors.New("mail: misformatted parenthetical comment")
+ }
+ if p.consume(';') {
+ p.skipCFWS()
+ break
+ }
+ if !p.consume(',') {
+ return nil, errors.New("mail: expected comma")
+ }
+ }
+ return group, nil
+}
+
+// consumeAddrSpec parses a single RFC 5322 addr-spec at the start of p.
+func (p *addrParser) consumeAddrSpec() (spec string, err error) {
+ debug.Printf("consumeAddrSpec: %q", p.s)
+
+ orig := *p
+ defer func() {
+ if err != nil {
+ *p = orig
+ }
+ }()
+
+ // local-part = dot-atom / quoted-string
+ var localPart string
+ p.skipSpace()
+ if p.empty() {
+ return "", errors.New("mail: no addr-spec")
+ }
+ if p.peek() == '"' {
+ // quoted-string
+ debug.Printf("consumeAddrSpec: parsing quoted-string")
+ localPart, err = p.consumeQuotedString()
+ if localPart == "" {
+ err = errors.New("mail: empty quoted string in addr-spec")
+ }
+ } else {
+ // dot-atom
+ debug.Printf("consumeAddrSpec: parsing dot-atom")
+ localPart, err = p.consumeAtom(true, false)
+ }
+ if err != nil {
+ debug.Printf("consumeAddrSpec: failed: %v", err)
+ return "", err
+ }
+
+ if !p.consume('@') {
+ return "", errors.New("mail: missing @ in addr-spec")
+ }
+
+ // domain = dot-atom / domain-literal
+ var domain string
+ p.skipSpace()
+ if p.empty() {
+ return "", errors.New("mail: no domain in addr-spec")
+ }
+ // TODO(dsymonds): Handle domain-literal
+ domain, err = p.consumeAtom(true, false)
+ if err != nil {
+ return "", err
+ }
+
+ return localPart + "@" + domain, nil
+}
+
+// consumePhrase parses the RFC 5322 phrase at the start of p.
+func (p *addrParser) consumePhrase() (phrase string, err error) {
+ debug.Printf("consumePhrase: [%s]", p.s)
+ // phrase = 1*word
+ var words []string
+ var isPrevEncoded bool
+ for {
+ // word = atom / quoted-string
+ var word string
+ p.skipSpace()
+ if p.empty() {
+ break
+ }
+ isEncoded := false
+ if p.peek() == '"' {
+ // quoted-string
+ word, err = p.consumeQuotedString()
+ } else {
+ // atom
+ // We actually parse dot-atom here to be more permissive
+ // than what RFC 5322 specifies.
+ word, err = p.consumeAtom(true, true)
+ if err == nil {
+ word, isEncoded, err = p.decodeRFC2047Word(word)
+ }
+ }
+
+ if err != nil {
+ break
+ }
+ debug.Printf("consumePhrase: consumed %q", word)
+ if isPrevEncoded && isEncoded {
+ words[len(words)-1] += word
+ } else {
+ words = append(words, word)
+ }
+ isPrevEncoded = isEncoded
+ }
+ // Ignore any error if we got at least one word.
+ if err != nil && len(words) == 0 {
+ debug.Printf("consumePhrase: hit err: %v", err)
+ return "", fmt.Errorf("mail: missing word in phrase: %v", err)
+ }
+ phrase = strings.Join(words, " ")
+ return phrase, nil
+}
+
+// consumeQuotedString parses the quoted string at the start of p.
+func (p *addrParser) consumeQuotedString() (qs string, err error) {
+ // Assume first byte is '"'.
+ i := 1
+ qsb := make([]rune, 0, 10)
+
+ escaped := false
+
+Loop:
+ for {
+ r, size := utf8.DecodeRuneInString(p.s[i:])
+
+ switch {
+ case size == 0:
+ return "", errors.New("mail: unclosed quoted-string")
+
+ case size == 1 && r == utf8.RuneError:
+ return "", fmt.Errorf("mail: invalid utf-8 in quoted-string: %q", p.s)
+
+ case escaped:
+ // quoted-pair = ("\" (VCHAR / WSP))
+
+ if !isVchar(r) && !isWSP(r) {
+ return "", fmt.Errorf("mail: bad character in quoted-string: %q", r)
+ }
+
+ qsb = append(qsb, r)
+ escaped = false
+
+ case isQtext(r) || isWSP(r):
+ // qtext (printable US-ASCII excluding " and \), or
+ // FWS (almost; we're ignoring CRLF)
+ qsb = append(qsb, r)
+
+ case r == '"':
+ break Loop
+
+ case r == '\\':
+ escaped = true
+
+ default:
+ return "", fmt.Errorf("mail: bad character in quoted-string: %q", r)
+
+ }
+
+ i += size
+ }
+ p.s = p.s[i+1:]
+ return string(qsb), nil
+}
+
+// consumeAtom parses an RFC 5322 atom at the start of p.
+// If dot is true, consumeAtom parses an RFC 5322 dot-atom instead.
+// If permissive is true, consumeAtom will not fail on:
+// - leading/trailing/double dots in the atom (see golang.org/issue/4938)
+// - special characters (RFC 5322 3.2.3) except '<', '>', ':' and '"' (see golang.org/issue/21018)
+func (p *addrParser) consumeAtom(dot bool, permissive bool) (atom string, err error) {
+ i := 0
+
+Loop:
+ for {
+ r, size := utf8.DecodeRuneInString(p.s[i:])
+ switch {
+ case size == 1 && r == utf8.RuneError:
+ return "", fmt.Errorf("mail: invalid utf-8 in address: %q", p.s)
+
+ case size == 0 || !isAtext(r, dot, permissive):
+ break Loop
+
+ default:
+ i += size
+
+ }
+ }
+
+ if i == 0 {
+ return "", errors.New("mail: invalid string")
+ }
+ atom, p.s = p.s[:i], p.s[i:]
+ if !permissive {
+ if strings.HasPrefix(atom, ".") {
+ return "", errors.New("mail: leading dot in atom")
+ }
+ if strings.Contains(atom, "..") {
+ return "", errors.New("mail: double dot in atom")
+ }
+ if strings.HasSuffix(atom, ".") {
+ return "", errors.New("mail: trailing dot in atom")
+ }
+ }
+ return atom, nil
+}
+
+func (p *addrParser) consumeDisplayNameComment() (string, error) {
+ if !p.consume('(') {
+ return "", errors.New("mail: comment does not start with (")
+ }
+ comment, ok := p.consumeComment()
+ if !ok {
+ return "", errors.New("mail: misformatted parenthetical comment")
+ }
+
+ // TODO(stapelberg): parse quoted-string within comment
+ words := strings.FieldsFunc(comment, func(r rune) bool { return r == ' ' || r == '\t' })
+ for idx, word := range words {
+ decoded, isEncoded, err := p.decodeRFC2047Word(word)
+ if err != nil {
+ return "", err
+ }
+ if isEncoded {
+ words[idx] = decoded
+ }
+ }
+
+ return strings.Join(words, " "), nil
+}
+
+func (p *addrParser) consume(c byte) bool {
+ if p.empty() || p.peek() != c {
+ return false
+ }
+ p.s = p.s[1:]
+ return true
+}
+
+// skipSpace skips the leading space and tab characters.
+func (p *addrParser) skipSpace() {
+ p.s = strings.TrimLeft(p.s, " \t")
+}
+
+func (p *addrParser) peek() byte {
+ return p.s[0]
+}
+
+func (p *addrParser) empty() bool {
+ return p.len() == 0
+}
+
+func (p *addrParser) len() int {
+ return len(p.s)
+}
+
+// skipCFWS skips CFWS as defined in RFC5322.
+func (p *addrParser) skipCFWS() bool {
+ p.skipSpace()
+
+ for {
+ if !p.consume('(') {
+ break
+ }
+
+ if _, ok := p.consumeComment(); !ok {
+ return false
+ }
+
+ p.skipSpace()
+ }
+
+ return true
+}
+
+func (p *addrParser) consumeComment() (string, bool) {
+ // '(' already consumed.
+ depth := 1
+
+ var comment string
+ for {
+ if p.empty() || depth == 0 {
+ break
+ }
+
+ if p.peek() == '\\' && p.len() > 1 {
+ p.s = p.s[1:]
+ } else if p.peek() == '(' {
+ depth++
+ } else if p.peek() == ')' {
+ depth--
+ }
+ if depth > 0 {
+ comment += p.s[:1]
+ }
+ p.s = p.s[1:]
+ }
+
+ return comment, depth == 0
+}
+
+func (p *addrParser) decodeRFC2047Word(s string) (word string, isEncoded bool, err error) {
+ if p.dec != nil {
+ word, err = p.dec.Decode(s)
+ } else {
+ word, err = rfc2047Decoder.Decode(s)
+ }
+
+ if err == nil {
+ return word, true, nil
+ }
+
+ if _, ok := err.(charsetError); ok {
+ return s, true, err
+ }
+
+ // Ignore invalid RFC 2047 encoded-word errors.
+ return s, false, nil
+}
+
+var rfc2047Decoder = mime.WordDecoder{
+ CharsetReader: func(charset string, input io.Reader) (io.Reader, error) {
+ return nil, charsetError(charset)
+ },
+}
+
+type charsetError string
+
+func (e charsetError) Error() string {
+ return fmt.Sprintf("charset not supported: %q", string(e))
+}
+
+// isAtext reports whether r is an RFC 5322 atext character.
+// If dot is true, period is included.
+// If permissive is true, RFC 5322 3.2.3 specials is included,
+// except '<', '>', ':' and '"'.
+func isAtext(r rune, dot, permissive bool) bool {
+ switch r {
+ case '.':
+ return dot
+
+ // RFC 5322 3.2.3. specials
+ case '(', ')', '[', ']', ';', '@', '\\', ',':
+ return permissive
+
+ case '<', '>', '"', ':':
+ return false
+ }
+ return isVchar(r)
+}
+
+// isQtext reports whether r is an RFC 5322 qtext character.
+func isQtext(r rune) bool {
+ // Printable US-ASCII, excluding backslash or quote.
+ if r == '\\' || r == '"' {
+ return false
+ }
+ return isVchar(r)
+}
+
+// quoteString renders a string as an RFC 5322 quoted-string.
+func quoteString(s string) string {
+ var buf strings.Builder
+ buf.WriteByte('"')
+ for _, r := range s {
+ if isQtext(r) || isWSP(r) {
+ buf.WriteRune(r)
+ } else if isVchar(r) {
+ buf.WriteByte('\\')
+ buf.WriteRune(r)
+ }
+ }
+ buf.WriteByte('"')
+ return buf.String()
+}
+
+// isVchar reports whether r is an RFC 5322 VCHAR character.
+func isVchar(r rune) bool {
+ // Visible (printing) characters.
+ return '!' <= r && r <= '~' || isMultibyte(r)
+}
+
+// isMultibyte reports whether r is a multi-byte UTF-8 character
+// as supported by RFC 6532
+func isMultibyte(r rune) bool {
+ return r >= utf8.RuneSelf
+}
+
+// isWSP reports whether r is a WSP (white space).
+// WSP is a space or horizontal tab (RFC 5234 Appendix B).
+func isWSP(r rune) bool {
+ return r == ' ' || r == '\t'
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-12 16:56:35 +0000