Add basic SMTP support

5 files changed, 196 insertions, 7 deletions

diff --git a/conn_pool.go b/conn_pool.go
index 6e244b0..1ccc879 100644
--- a/conn_pool.go
+++ b/conn_pool.go
@@ -21,14 +21,14 @@ func generateToken() (string, error) {
 var ErrSessionExpired = errors.New("session expired")
 
 type Session struct {
-	imapConn *imapclient.Client
+	imapConn           *imapclient.Client
 	username, password string
 }
 
 // TODO: expiration timer
 type ConnPool struct {
-	locker sync.Mutex
-	sessions  map[string]*Session
+	locker   sync.Mutex
+	sessions map[string]*Session
 }
 
 func NewConnPool() *ConnPool {
diff --git a/go.mod b/go.mod
index 669cb67..be3095a 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,14 @@ go 1.13
 
 require (
 	github.com/emersion/go-imap v1.0.1
-	github.com/emersion/go-message v0.10.4-0.20190609165112-592ace5bc1ca
+	github.com/emersion/go-message v0.10.8
+	github.com/emersion/go-sasl v0.0.0-20190817083125-240c8404624e
+	github.com/emersion/go-smtp v0.12.0
 	github.com/labstack/echo/v4 v4.1.11
+	github.com/mattn/go-colorable v0.1.4 // indirect
+	github.com/mattn/go-isatty v0.0.10 // indirect
+	github.com/valyala/fasttemplate v1.1.0 // indirect
+	golang.org/x/crypto v0.0.0-20191202143827-86a70503ff7e // indirect
+	golang.org/x/net v0.0.0-20191126235420-ef20fe5d7933 // indirect
+	golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9 // indirect
 )
diff --git a/go.sum b/go.sum
index 0e963f9..9a2c1a0 100644
--- a/go.sum
+++ b/go.sum
@@ -1,46 +1,76 @@
 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=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumCAMpl/TFQ4/5kLM=
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/emersion/go-imap v1.0.1 h1:J3duplefIrglQtE63hCGYdGLgMjYWqHvkUUEbimbXY8=
 github.com/emersion/go-imap v1.0.1/go.mod h1:MEiDDwwQFcZ+L45Pa68jNGv0qU9kbW+SJzwDpvSfX1s=
 github.com/emersion/go-message v0.10.4-0.20190609165112-592ace5bc1ca h1:OYhqtJI4eOLvGtRIsUfP87VMJ1J/o6ks1tah9DlYkn4=
 github.com/emersion/go-message v0.10.4-0.20190609165112-592ace5bc1ca/go.mod h1:3h+HsGTCFHmk4ngJ2IV/YPhdlaOcR6hcgqM3yca9v7c=
+github.com/emersion/go-message v0.10.8 h1:1l1Vb+0By9U1ITTH3FgKfJQWQ9sTI3N1smPe6SS3QXY=
+github.com/emersion/go-message v0.10.8/go.mod h1:C4jnca5HOTo4bGN9YdqNQM9sITuT3Y0K6bSUw9RklvY=
 github.com/emersion/go-sasl v0.0.0-20190520160400-47d427600317 h1:tYZxAY8nu3JJQKios9f27Sbvbkfm4XHXT476gVtszu0=
 github.com/emersion/go-sasl v0.0.0-20190520160400-47d427600317/go.mod h1:G/dpzLu16WtQpBfQ/z3LYiYJn3ZhKSGWn83fyoyQe/k=
+github.com/emersion/go-sasl v0.0.0-20190704090222-36b50694675c h1:Spm8jy+jWYG/Dn6ygbq/LBW/6M27kg59GK+FkKjexuw=
+github.com/emersion/go-sasl v0.0.0-20190704090222-36b50694675c/go.mod h1:G/dpzLu16WtQpBfQ/z3LYiYJn3ZhKSGWn83fyoyQe/k=
+github.com/emersion/go-sasl v0.0.0-20190817083125-240c8404624e h1:ba7YsgX5OV8FjGi5ZWml8Jng6oBrJAb3ahqWMJ5Ce8Q=
+github.com/emersion/go-sasl v0.0.0-20190817083125-240c8404624e/go.mod h1:G/dpzLu16WtQpBfQ/z3LYiYJn3ZhKSGWn83fyoyQe/k=
+github.com/emersion/go-smtp v0.12.0 h1:uo4pWTlHsdbkljojOwNRwzMFh/yKIbe/WRwjQ8JMYrg=
+github.com/emersion/go-smtp v0.12.0/go.mod h1:nJgxVrypNWIDhN0BJl0Hb+S61RQ9ZEFt6V/y0kpsZyQ=
 github.com/emersion/go-textwrapper v0.0.0-20160606182133-d0e65e56babe h1:40SWqY0zE3qCi6ZrtTf5OUdNm5lDnGnjRSq9GgmeTrg=
 github.com/emersion/go-textwrapper v0.0.0-20160606182133-d0e65e56babe/go.mod h1:aqO8z8wPrjkscevZJFVE1wXJrLpC5LtJG7fqLOsPb2U=
-github.com/labstack/echo v3.3.10+incompatible h1:pGRcYk231ExFAyoAjAfD85kQzRJCRI8bbnE7CX5OEgg=
 github.com/labstack/echo/v4 v4.1.11 h1:z0BZoArY4FqdpUEl+wlHp4hnr/oSR6MTmQmv8OHSoww=
 github.com/labstack/echo/v4 v4.1.11/go.mod h1:i541M3Fj6f76NZtHSj7TXnyM8n2gaodfvfxNnFqi74g=
 github.com/labstack/gommon v0.3.0 h1:JEeO0bvc78PKdyHxloTKiF8BD5iGrH8T6MSeGvSgob0=
 github.com/labstack/gommon v0.3.0/go.mod h1:MULnywXg0yavhxWKc+lOruYdAhDwPK9wf0OL7NoOu+k=
+github.com/martinlindhe/base36 v0.0.0-20190418230009-7c6542dfbb41 h1:CVsnY46BCLkX9XOhALJ/S7yb9ayc4eqjXSXO3tyB66A=
 github.com/martinlindhe/base36 v0.0.0-20190418230009-7c6542dfbb41/go.mod h1:+AtEs8xrBpCeYgSLoY/aJ6Wf37jtBuR0s35750M27+8=
+github.com/martinlindhe/base36 v1.0.0 h1:eYsumTah144C0A8P1T/AVSUk5ZoLnhfYFM3OGQxB52A=
+github.com/martinlindhe/base36 v1.0.0/go.mod h1:+AtEs8xrBpCeYgSLoY/aJ6Wf37jtBuR0s35750M27+8=
 github.com/mattn/go-colorable v0.1.2 h1:/bC9yWikZXAL9uJdulbSfyVNIR3n3trXl+v8+1sx8mU=
 github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
+github.com/mattn/go-colorable v0.1.4 h1:snbPLB8fVfU9iwbbo30TPtbLRzwWu6aJS6Xh4eaaviA=
+github.com/mattn/go-colorable v0.1.4/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
 github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
 github.com/mattn/go-isatty v0.0.9 h1:d5US/mDsogSGW37IV293h//ZFaeajb69h+EHFsv2xGg=
 github.com/mattn/go-isatty v0.0.9/go.mod h1:YNRxwqDuOph6SZLI9vUUz6OYw3QyUt7WiY2yME+cCiQ=
+github.com/mattn/go-isatty v0.0.10 h1:qxFzApOv4WsAL965uUPIsXzAKCZxN2p9UqdhFS4ZW10=
+github.com/mattn/go-isatty v0.0.10/go.mod h1:qgIWMr58cqv1PHHyhnkY9lrL7etaEgOFcMEpPG5Rm84=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
 github.com/valyala/fasttemplate v1.0.1 h1:tY9CJiPnMXf1ERmG2EyK7gNUd+c6RKGD0IfU8WdUSz8=
 github.com/valyala/fasttemplate v1.0.1/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
+github.com/valyala/fasttemplate v1.1.0 h1:RZqt0yGBsps8NGvLSGW804QQqCUYYLsaOjTVHy1Ocw4=
+github.com/valyala/fasttemplate v1.1.0/go.mod h1:UQGH1tvbgY+Nz5t2n7tXsz52dQxojPUpymEIMZ47gx8=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4 h1:HuIa8hRrWRSrqYzx1qI49NNxhdi2PrY7gxVSq1JjLDc=
 golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20191202143827-86a70503ff7e h1:egKlR8l7Nu9vHGWbcUV8lqR4987UfUbBd7GbhqGzNYU=
+golang.org/x/crypto v0.0.0-20191202143827-86a70503ff7e/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20191126235420-ef20fe5d7933 h1:e6HwijUxhDe+hPNjZQQn9bA5PW3vNmnN64U2ZW759Lk=
+golang.org/x/net v0.0.0-20191126235420-ef20fe5d7933/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a h1:aYOabOQFp6Vj6W1F80affTUvO9UxmJRx8K0gsfABByQ=
 golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9 h1:ZBzSG/7F4eNKz2L3GE9o300RX0Az1Bw5HF7PDraD+qU=
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 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+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.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/server.go b/server.go
index be174b8..6a12122 100644
--- a/server.go
+++ b/server.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	imapclient "github.com/emersion/go-imap/client"
+	"github.com/emersion/go-sasl"
 	"github.com/labstack/echo/v4"
 )
 
@@ -92,9 +93,9 @@ func NewServer(imapURL, smtpURL string) (*Server, error) {
 
 type context struct {
 	echo.Context
-	server *Server
+	server  *Server
 	session *Session
-	conn   *imapclient.Client
+	conn    *imapclient.Client
 }
 
 var aLongTimeAgo = time.Unix(233431200, 0)
@@ -200,6 +201,44 @@ func handleGetPart(ctx *context, raw bool) error {
 
 func handleCompose(ectx echo.Context) error {
 	ctx := ectx.(*context)
+
+	if ctx.Request().Method == http.MethodPost {
+		// TODO: parse address lists
+		from := ctx.FormValue("from")
+		to := ctx.FormValue("to")
+		subject := ctx.FormValue("subject")
+		text := ctx.FormValue("text")
+
+		c, err := ctx.server.connectSMTP()
+		if err != nil {
+			return err
+		}
+		defer c.Close()
+
+		auth := sasl.NewPlainClient("", ctx.session.username, ctx.session.password)
+		if err := c.Auth(auth); err != nil {
+			return echo.NewHTTPError(http.StatusForbidden, err)
+		}
+
+		msg := OutgoingMessage{
+			from: from,
+			to: []string{to},
+			subject: subject,
+			text: text,
+		}
+		if err := sendMessage(c, &msg); err != nil {
+			return err
+		}
+
+		if err := c.Quit(); err != nil {
+			return fmt.Errorf("QUIT failed: %v", err)
+		}
+
+		// TODO: append to IMAP Sent mailbox
+
+		return ctx.Redirect(http.StatusFound, "/mailbox/INBOX")
+	}
+
 	return ctx.Render(http.StatusOK, "compose.html", nil)
 }
 
diff --git a/smtp.go b/smtp.go
new file mode 100644
index 0000000..d4b8ea2
--- /dev/null
+++ b/smtp.go
@@ -0,0 +1,112 @@
+package koushin
+
+import (
+	"fmt"
+	"time"
+	"io"
+
+	"github.com/emersion/go-message/mail"
+	"github.com/emersion/go-smtp"
+)
+
+func (s *Server) connectSMTP() (*smtp.Client, error) {
+	var c *smtp.Client
+	var err error
+	if s.smtp.tls {
+		c, err = smtp.DialTLS(s.smtp.host, nil)
+		if err != nil {
+			return nil, fmt.Errorf("failed to connect to SMTPS server: %v", err)
+		}
+	} else {
+		c, err = smtp.Dial(s.smtp.host)
+		if err != nil {
+			return nil, fmt.Errorf("failed to connect to SMTP server: %v", err)
+		}
+		if !s.smtp.insecure {
+			if err := c.StartTLS(nil); err != nil {
+				c.Close()
+				return nil, fmt.Errorf("STARTTLS failed: %v", err)
+			}
+		}
+	}
+
+	return c, err
+}
+
+type OutgoingMessage struct {
+	from string
+	to []string
+	subject string
+	text string
+}
+
+func (msg *OutgoingMessage) WriteTo(w io.Writer) error {
+	from := []*mail.Address{{"", msg.from}}
+
+	to := make([]*mail.Address, len(msg.to))
+	for i, addr := range msg.to {
+		to[i] = &mail.Address{"", addr}
+	}
+
+	var h mail.Header
+	h.SetDate(time.Now())
+	h.SetAddressList("From", from)
+	h.SetAddressList("To", to)
+	h.SetText("Subject", msg.subject)
+
+	mw, err := mail.CreateWriter(w, h)
+	if err != nil {
+		return fmt.Errorf("failed to create mail writer: %v", err)
+	}
+
+	var th mail.InlineHeader
+	th.Set("Content-Type", "text/plain; charset=utf-8")
+
+	tw, err := mw.CreateSingleInline(th)
+	if err != nil {
+		return fmt.Errorf("failed to create text part: %v", err)
+	}
+	defer tw.Close()
+
+	if _, err := io.WriteString(tw, msg.text); err != nil {
+		return fmt.Errorf("failed to write text part: %v", err)
+	}
+
+	if err := tw.Close(); err != nil {
+		return fmt.Errorf("failed to close text part: %v", err)
+	}
+
+	if err := mw.Close(); err != nil {
+		return fmt.Errorf("failed to close mail writer: %v", err)
+	}
+
+	return nil
+}
+
+func sendMessage(c *smtp.Client, msg *OutgoingMessage) error {
+	if err := c.Mail(msg.from, nil); err != nil {
+		return fmt.Errorf("MAIL FROM failed: %v", err)
+	}
+
+	for _, to := range msg.to {
+		if err := c.Rcpt(to); err != nil {
+			return fmt.Errorf("RCPT TO failed: %v", err)
+		}
+	}
+
+	w, err := c.Data()
+	if err != nil {
+		return fmt.Errorf("DATA failed: %v", err)
+	}
+	defer w.Close()
+
+	if err := msg.WriteTo(w); err != nil {
+		return fmt.Errorf("failed to write outgoing message: %v", err)
+	}
+
+	if err := w.Close(); err != nil {
+		return fmt.Errorf("failed to close SMTP data writer: %v", err)
+	}
+
+	return nil
+}