diff --git a/utils/mail.go b/utils/mail.go new file mode 100644 index 00000000..5096111b --- /dev/null +++ b/utils/mail.go @@ -0,0 +1,299 @@ +package utils + +import ( + "bytes" + "encoding/base64" + "encoding/json" + "errors" + "fmt" + "io" + "mime" + "mime/multipart" + "net/mail" + "net/smtp" + "net/textproto" + "os" + "path" + "path/filepath" + "strconv" + "strings" +) + +const ( + maxLineLength = 76 +) + +// Email is the type used for email messages +type Email struct { + Auth smtp.Auth + Identity string `json:"identity"` + Username string `json:"username"` + Password string `json:"password"` + Host string `json:"host"` + Port int `json:"port"` + From string `json:"from"` + To []string + Bcc []string + Cc []string + Subject string + Text string // Plaintext message (optional) + HTML string // Html message (optional) + Headers textproto.MIMEHeader + Attachments []*Attachment + ReadReceipt []string +} + +// Attachment is a struct representing an email attachment. +// Based on the mime/multipart.FileHeader struct, Attachment contains the name, MIMEHeader, and content of the attachment in question +type Attachment struct { + Filename string + Header textproto.MIMEHeader + Content []byte +} + +func NewEMail(config string) *Email { + e := new(Email) + e.Headers = textproto.MIMEHeader{} + err := json.Unmarshal([]byte(config), e) + if err != nil { + return nil + } + if e.From == "" { + e.From = e.Username + } + return e +} + +// make all send information to byte +func (e *Email) Bytes() ([]byte, error) { + buff := &bytes.Buffer{} + w := multipart.NewWriter(buff) + // Set the appropriate headers (overwriting any conflicts) + // Leave out Bcc (only included in envelope headers) + e.Headers.Set("To", strings.Join(e.To, ",")) + if e.Cc != nil { + e.Headers.Set("Cc", strings.Join(e.Cc, ",")) + } + e.Headers.Set("From", e.From) + e.Headers.Set("Subject", e.Subject) + if len(e.ReadReceipt) != 0 { + e.Headers.Set("Disposition-Notification-To", strings.Join(e.ReadReceipt, ",")) + } + e.Headers.Set("MIME-Version", "1.0") + e.Headers.Set("Content-Type", fmt.Sprintf("multipart/mixed;\r\n boundary=%s\r\n", w.Boundary())) + + // Write the envelope headers (including any custom headers) + if err := headerToBytes(buff, e.Headers); err != nil { + return nil, fmt.Errorf("Failed to render message headers: %s", err) + } + // Start the multipart/mixed part + fmt.Fprintf(buff, "--%s\r\n", w.Boundary()) + header := textproto.MIMEHeader{} + // Check to see if there is a Text or HTML field + if e.Text != "" || e.HTML != "" { + subWriter := multipart.NewWriter(buff) + // Create the multipart alternative part + header.Set("Content-Type", fmt.Sprintf("multipart/alternative;\r\n boundary=%s\r\n", subWriter.Boundary())) + // Write the header + if err := headerToBytes(buff, header); err != nil { + return nil, fmt.Errorf("Failed to render multipart message headers: %s", err) + } + // Create the body sections + if e.Text != "" { + header.Set("Content-Type", fmt.Sprintf("text/plain; charset=UTF-8")) + header.Set("Content-Transfer-Encoding", "quoted-printable") + if _, err := subWriter.CreatePart(header); err != nil { + return nil, err + } + // Write the text + if err := quotePrintEncode(buff, e.Text); err != nil { + return nil, err + } + } + if e.HTML != "" { + header.Set("Content-Type", fmt.Sprintf("text/html; charset=UTF-8")) + header.Set("Content-Transfer-Encoding", "quoted-printable") + if _, err := subWriter.CreatePart(header); err != nil { + return nil, err + } + // Write the text + if err := quotePrintEncode(buff, e.HTML); err != nil { + return nil, err + } + } + if err := subWriter.Close(); err != nil { + return nil, err + } + } + // Create attachment part, if necessary + for _, a := range e.Attachments { + ap, err := w.CreatePart(a.Header) + if err != nil { + return nil, err + } + // Write the base64Wrapped content to the part + base64Wrap(ap, a.Content) + } + if err := w.Close(); err != nil { + return nil, err + } + return buff.Bytes(), nil +} + +// Attach file to the send mail +func (e *Email) AttachFile(filename string) (a *Attachment, err error) { + f, err := os.Open(filename) + if err != nil { + return + } + ct := mime.TypeByExtension(filepath.Ext(filename)) + basename := path.Base(filename) + return e.Attach(f, basename, ct) +} + +// Attach is used to attach content from an io.Reader to the email. +// Required parameters include an io.Reader, the desired filename for the attachment, and the Content-Type +func (e *Email) Attach(r io.Reader, filename string, c string) (a *Attachment, err error) { + var buffer bytes.Buffer + if _, err = io.Copy(&buffer, r); err != nil { + return + } + at := &Attachment{ + Filename: filename, + Header: textproto.MIMEHeader{}, + Content: buffer.Bytes(), + } + // Get the Content-Type to be used in the MIMEHeader + if c != "" { + at.Header.Set("Content-Type", c) + } else { + // If the Content-Type is blank, set the Content-Type to "application/octet-stream" + at.Header.Set("Content-Type", "application/octet-stream") + } + at.Header.Set("Content-Disposition", fmt.Sprintf("attachment;\r\n filename=\"%s\"", filename)) + at.Header.Set("Content-Transfer-Encoding", "base64") + e.Attachments = append(e.Attachments, at) + return at, nil +} + +func (e *Email) Send() error { + if e.Auth == nil { + e.Auth = smtp.PlainAuth(e.Identity, e.Username, e.Password, e.Host) + } + // Merge the To, Cc, and Bcc fields + to := make([]string, 0, len(e.To)+len(e.Cc)+len(e.Bcc)) + to = append(append(append(to, e.To...), e.Cc...), e.Bcc...) + // Check to make sure there is at least one recipient and one "From" address + if e.From == "" || len(to) == 0 { + return errors.New("Must specify at least one From address and one To address") + } + from, err := mail.ParseAddress(e.From) + if err != nil { + return err + } + raw, err := e.Bytes() + if err != nil { + return err + } + return smtp.SendMail(e.Host+":"+strconv.Itoa(e.Port), e.Auth, from.Address, to, raw) +} + +// quotePrintEncode writes the quoted-printable text to the IO Writer (according to RFC 2045) +func quotePrintEncode(w io.Writer, s string) error { + var buf [3]byte + mc := 0 + for i := 0; i < len(s); i++ { + c := s[i] + // We're assuming Unix style text formats as input (LF line break), and + // quoted-printble uses CRLF line breaks. (Literal CRs will become + // "=0D", but probably shouldn't be there to begin with!) + if c == '\n' { + io.WriteString(w, "\r\n") + mc = 0 + continue + } + + var nextOut []byte + if isPrintable(c) { + nextOut = append(buf[:0], c) + } else { + nextOut = buf[:] + qpEscape(nextOut, c) + } + + // Add a soft line break if the next (encoded) byte would push this line + // to or past the limit. + if mc+len(nextOut) >= maxLineLength { + if _, err := io.WriteString(w, "=\r\n"); err != nil { + return err + } + mc = 0 + } + + if _, err := w.Write(nextOut); err != nil { + return err + } + mc += len(nextOut) + } + // No trailing end-of-line?? Soft line break, then. TODO: is this sane? + if mc > 0 { + io.WriteString(w, "=\r\n") + } + return nil +} + +// isPrintable returns true if the rune given is "printable" according to RFC 2045, false otherwise +func isPrintable(c byte) bool { + return (c >= '!' && c <= '<') || (c >= '>' && c <= '~') || (c == ' ' || c == '\n' || c == '\t') +} + +// qpEscape is a helper function for quotePrintEncode which escapes a +// non-printable byte. Expects len(dest) == 3. +func qpEscape(dest []byte, c byte) { + const nums = "0123456789ABCDEF" + dest[0] = '=' + dest[1] = nums[(c&0xf0)>>4] + dest[2] = nums[(c & 0xf)] +} + +// headerToBytes enumerates the key and values in the header, and writes the results to the IO Writer +func headerToBytes(w io.Writer, t textproto.MIMEHeader) error { + for k, v := range t { + // Write the header key + _, err := fmt.Fprintf(w, "%s:", k) + if err != nil { + return err + } + // Write each value in the header + for _, c := range v { + _, err := fmt.Fprintf(w, " %s\r\n", c) + if err != nil { + return err + } + } + } + return nil +} + +// base64Wrap encodeds the attachment content, and wraps it according to RFC 2045 standards (every 76 chars) +// The output is then written to the specified io.Writer +func base64Wrap(w io.Writer, b []byte) { + // 57 raw bytes per 76-byte base64 line. + const maxRaw = 57 + // Buffer for each line, including trailing CRLF. + var buffer [maxLineLength + len("\r\n")]byte + copy(buffer[maxLineLength:], "\r\n") + // Process raw chunks until there's no longer enough to fill a line. + for len(b) >= maxRaw { + base64.StdEncoding.Encode(buffer[:], b[:maxRaw]) + w.Write(buffer[:]) + b = b[maxRaw:] + } + // Handle the last chunk of bytes. + if len(b) > 0 { + out := buffer[:base64.StdEncoding.EncodedLen(len(b))] + base64.StdEncoding.Encode(out, b) + out = append(out, "\r\n"...) + w.Write(out) + } +} diff --git a/utils/mail_test.go b/utils/mail_test.go new file mode 100644 index 00000000..a75c8681 --- /dev/null +++ b/utils/mail_test.go @@ -0,0 +1,24 @@ +package utils + +import "testing" + +func TestMail(t *testing.T) { + config := `{"username":"astaxie@gmail.com","password":"astaxie","host":"smtp.gmail.com","port":587}` + mail := NewEMail(config) + if mail.Username != "astaxie@gmail.com" { + t.Fatal("email parse get username error") + } + if mail.Password != "astaxie" { + t.Fatal("email parse get password error") + } + if mail.Host != "smtp.gmail.com" { + t.Fatal("email parse get host error") + } + if mail.Port != 587 { + t.Fatal("email parse get port error") + } + mail.To = []string{"xiemengjun@gmail.com"} + mail.From = "astaxie@gmail.com" + mail.Subject = "hi, just from beego!" + mail.Send() +}