From d103ed6ca97ca5a2669f6cf5fe4b3d2a9c945f26 Mon Sep 17 00:00:00 2001 From: Christopher Speller Date: Wed, 17 May 2017 16:51:25 -0400 Subject: Upgrading server dependancies (#6431) --- .../alexcesaro/quotedprintable.v3/encodedword.go | 279 +++++++++++++++++++++ 1 file changed, 279 insertions(+) create mode 100644 vendor/gopkg.in/alexcesaro/quotedprintable.v3/encodedword.go (limited to 'vendor/gopkg.in/alexcesaro/quotedprintable.v3/encodedword.go') diff --git a/vendor/gopkg.in/alexcesaro/quotedprintable.v3/encodedword.go b/vendor/gopkg.in/alexcesaro/quotedprintable.v3/encodedword.go new file mode 100644 index 000000000..cfd02617c --- /dev/null +++ b/vendor/gopkg.in/alexcesaro/quotedprintable.v3/encodedword.go @@ -0,0 +1,279 @@ +package quotedprintable + +import ( + "bytes" + "encoding/base64" + "errors" + "fmt" + "io" + "strings" + "unicode" + "unicode/utf8" +) + +// A WordEncoder is a RFC 2047 encoded-word encoder. +type WordEncoder byte + +const ( + // BEncoding represents Base64 encoding scheme as defined by RFC 2045. + BEncoding = WordEncoder('b') + // QEncoding represents the Q-encoding scheme as defined by RFC 2047. + QEncoding = WordEncoder('q') +) + +var ( + errInvalidWord = errors.New("mime: invalid RFC 2047 encoded-word") +) + +// Encode returns the encoded-word form of s. If s is ASCII without special +// characters, it is returned unchanged. The provided charset is the IANA +// charset name of s. It is case insensitive. +func (e WordEncoder) Encode(charset, s string) string { + if !needsEncoding(s) { + return s + } + return e.encodeWord(charset, s) +} + +func needsEncoding(s string) bool { + for _, b := range s { + if (b < ' ' || b > '~') && b != '\t' { + return true + } + } + return false +} + +// encodeWord encodes a string into an encoded-word. +func (e WordEncoder) encodeWord(charset, s string) string { + buf := getBuffer() + defer putBuffer(buf) + + buf.WriteString("=?") + buf.WriteString(charset) + buf.WriteByte('?') + buf.WriteByte(byte(e)) + buf.WriteByte('?') + + if e == BEncoding { + w := base64.NewEncoder(base64.StdEncoding, buf) + io.WriteString(w, s) + w.Close() + } else { + enc := make([]byte, 3) + for i := 0; i < len(s); i++ { + b := s[i] + switch { + case b == ' ': + buf.WriteByte('_') + case b <= '~' && b >= '!' && b != '=' && b != '?' && b != '_': + buf.WriteByte(b) + default: + enc[0] = '=' + enc[1] = upperhex[b>>4] + enc[2] = upperhex[b&0x0f] + buf.Write(enc) + } + } + } + buf.WriteString("?=") + return buf.String() +} + +const upperhex = "0123456789ABCDEF" + +// A WordDecoder decodes MIME headers containing RFC 2047 encoded-words. +type WordDecoder struct { + // CharsetReader, if non-nil, defines a function to generate + // charset-conversion readers, converting from the provided + // charset into UTF-8. + // Charsets are always lower-case. utf-8, iso-8859-1 and us-ascii charsets + // are handled by default. + // One of the the CharsetReader's result values must be non-nil. + CharsetReader func(charset string, input io.Reader) (io.Reader, error) +} + +// Decode decodes an encoded-word. If word is not a valid RFC 2047 encoded-word, +// word is returned unchanged. +func (d *WordDecoder) Decode(word string) (string, error) { + fields := strings.Split(word, "?") // TODO: remove allocation? + if len(fields) != 5 || fields[0] != "=" || fields[4] != "=" || len(fields[2]) != 1 { + return "", errInvalidWord + } + + content, err := decode(fields[2][0], fields[3]) + if err != nil { + return "", err + } + + buf := getBuffer() + defer putBuffer(buf) + + if err := d.convert(buf, fields[1], content); err != nil { + return "", err + } + + return buf.String(), nil +} + +// DecodeHeader decodes all encoded-words of the given string. It returns an +// error if and only if CharsetReader of d returns an error. +func (d *WordDecoder) DecodeHeader(header string) (string, error) { + // If there is no encoded-word, returns before creating a buffer. + i := strings.Index(header, "=?") + if i == -1 { + return header, nil + } + + buf := getBuffer() + defer putBuffer(buf) + + buf.WriteString(header[:i]) + header = header[i:] + + betweenWords := false + for { + start := strings.Index(header, "=?") + if start == -1 { + break + } + cur := start + len("=?") + + i := strings.Index(header[cur:], "?") + if i == -1 { + break + } + charset := header[cur : cur+i] + cur += i + len("?") + + if len(header) < cur+len("Q??=") { + break + } + encoding := header[cur] + cur++ + + if header[cur] != '?' { + break + } + cur++ + + j := strings.Index(header[cur:], "?=") + if j == -1 { + break + } + text := header[cur : cur+j] + end := cur + j + len("?=") + + content, err := decode(encoding, text) + if err != nil { + betweenWords = false + buf.WriteString(header[:start+2]) + header = header[start+2:] + continue + } + + // Write characters before the encoded-word. White-space and newline + // characters separating two encoded-words must be deleted. + if start > 0 && (!betweenWords || hasNonWhitespace(header[:start])) { + buf.WriteString(header[:start]) + } + + if err := d.convert(buf, charset, content); err != nil { + return "", err + } + + header = header[end:] + betweenWords = true + } + + if len(header) > 0 { + buf.WriteString(header) + } + + return buf.String(), nil +} + +func decode(encoding byte, text string) ([]byte, error) { + switch encoding { + case 'B', 'b': + return base64.StdEncoding.DecodeString(text) + case 'Q', 'q': + return qDecode(text) + } + return nil, errInvalidWord +} + +func (d *WordDecoder) convert(buf *bytes.Buffer, charset string, content []byte) error { + switch { + case strings.EqualFold("utf-8", charset): + buf.Write(content) + case strings.EqualFold("iso-8859-1", charset): + for _, c := range content { + buf.WriteRune(rune(c)) + } + case strings.EqualFold("us-ascii", charset): + for _, c := range content { + if c >= utf8.RuneSelf { + buf.WriteRune(unicode.ReplacementChar) + } else { + buf.WriteByte(c) + } + } + default: + if d.CharsetReader == nil { + return fmt.Errorf("mime: unhandled charset %q", charset) + } + r, err := d.CharsetReader(strings.ToLower(charset), bytes.NewReader(content)) + if err != nil { + return err + } + if _, err = buf.ReadFrom(r); err != nil { + return err + } + } + return nil +} + +// hasNonWhitespace reports whether s (assumed to be ASCII) contains at least +// one byte of non-whitespace. +func hasNonWhitespace(s string) bool { + for _, b := range s { + switch b { + // Encoded-words can only be separated by linear white spaces which does + // not include vertical tabs (\v). + case ' ', '\t', '\n', '\r': + default: + return true + } + } + return false +} + +// qDecode decodes a Q encoded string. +func qDecode(s string) ([]byte, error) { + dec := make([]byte, len(s)) + n := 0 + for i := 0; i < len(s); i++ { + switch c := s[i]; { + case c == '_': + dec[n] = ' ' + case c == '=': + if i+2 >= len(s) { + return nil, errInvalidWord + } + b, err := readHexByte(s[i+1], s[i+2]) + if err != nil { + return nil, err + } + dec[n] = b + i += 2 + case (c <= '~' && c >= ' ') || c == '\n' || c == '\r' || c == '\t': + dec[n] = c + default: + return nil, errInvalidWord + } + n++ + } + + return dec[:n], nil +} -- cgit v1.2.3-1-g7c22