smtp + email confirmation (#285)

* add smtp configuration

* add email confirm + reset templates

* add email sender to testrig

* flesh out the email sender interface

* go fmt

* golint

* update from field with more clarity

* tidy up the email formatting

* fix tests

* add email sender to processor

* tidy client api processing a bit

* further tidying in fromClientAPI

* pin new account to user

* send msg to processor on new account creation

* generate confirm email uri

* remove emailer from account processor again

* add processCreateAccountFromClientAPI

* move emailer accountprocessor => userprocessor

* add email sender to user processor

* SendConfirmEmail function

* add noop email sender

* use noop email sender in tests

* only assemble message if callback is not nil

* use noop email sender if no smtp host is defined

* minify email html before sending

* fix wrong email address

* email confirm test

* fmt

* serve web hndler

* add email confirm handler

* init test log properly on testrig

* log emails that *would* have been sent

* go fmt ./...

* unexport confirm email handler

* updatedAt

* test confirm email function

* don't allow tokens older than 7 days

* change error message a bit

* add basic smtp docs

* add a few more snippets

* typo

* add email sender to outbox tests

* don't use dutch wikipedia link

* don't minify email html

7 files changed, 385 insertions, 2 deletions

diff --git a/internal/email/confirm.go b/internal/email/confirm.go
new file mode 100644
index 000000000..78f661fe1
--- /dev/null
+++ b/internal/email/confirm.go
@@ -0,0 +1,53 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package email
+
+import (
+	"bytes"
+	"net/smtp"
+)
+
+const (
+	confirmTemplate = "email_confirm.tmpl"
+	confirmSubject  = "Subject: GoToSocial Email Confirmation"
+)
+
+func (s *sender) SendConfirmEmail(toAddress string, data ConfirmData) error {
+	buf := &bytes.Buffer{}
+	if err := s.template.ExecuteTemplate(buf, confirmTemplate, data); err != nil {
+		return err
+	}
+	confirmBody := buf.String()
+
+	msg := assembleMessage(confirmSubject, confirmBody, toAddress, s.from)
+	return smtp.SendMail(s.hostAddress, s.auth, s.from, []string{toAddress}, msg)
+}
+
+// ConfirmData represents data passed into the confirm email address template.
+type ConfirmData struct {
+	// Username to be addressed.
+	Username string
+	// URL of the instance to present to the receiver.
+	InstanceURL string
+	// Name of the instance to present to the receiver.
+	InstanceName string
+	// Link to present to the receiver to click on and do the confirmation.
+	// Should be a full link with protocol eg., https://example.org/confirm_email?token=some-long-token
+	ConfirmLink string
+}
diff --git a/internal/email/email.go b/internal/email/email_test.go
index 3d6a9dd2d..4e2619546 100644
--- a/internal/email/email.go
+++ b/internal/email/email_test.go
@@ -16,5 +16,24 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-// Package email provides a service for interacting with an SMTP server
-package email
+package email_test
+
+import (
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/email"
+	"github.com/superseriousbusiness/gotosocial/testrig"
+)
+
+type EmailTestSuite struct {
+	suite.Suite
+
+	sender email.Sender
+
+	sentEmails map[string]string
+}
+
+func (suite *EmailTestSuite) SetupTest() {
+	testrig.InitTestLog()
+	suite.sentEmails = make(map[string]string)
+	suite.sender = testrig.NewEmailSender("../../web/template/", suite.sentEmails)
+}
diff --git a/internal/email/noopsender.go b/internal/email/noopsender.go
new file mode 100644
index 000000000..82eb8db44
--- /dev/null
+++ b/internal/email/noopsender.go
@@ -0,0 +1,82 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package email
+
+import (
+	"bytes"
+	"html/template"
+
+	"github.com/sirupsen/logrus"
+)
+
+// NewNoopSender returns a no-op email sender that will just execute the given sendCallback
+// every time it would otherwise send an email to the given toAddress with the given message value.
+//
+// Passing a nil function is also acceptable, in which case the send functions will just return nil.
+func NewNoopSender(templateBaseDir string, sendCallback func(toAddress string, message string)) (Sender, error) {
+	t, err := loadTemplates(templateBaseDir)
+	if err != nil {
+		return nil, err
+	}
+
+	return &noopSender{
+		sendCallback: sendCallback,
+		template:     t,
+	}, nil
+}
+
+type noopSender struct {
+	sendCallback func(toAddress string, message string)
+	template     *template.Template
+}
+
+func (s *noopSender) SendConfirmEmail(toAddress string, data ConfirmData) error {
+	buf := &bytes.Buffer{}
+	if err := s.template.ExecuteTemplate(buf, confirmTemplate, data); err != nil {
+		return err
+	}
+	confirmBody := buf.String()
+
+	msg := assembleMessage(confirmSubject, confirmBody, toAddress, "test@example.org")
+
+	logrus.Tracef("NOT SENDING confirmation email to %s with contents: %s", toAddress, msg)
+
+	if s.sendCallback != nil {
+		s.sendCallback(toAddress, string(msg))
+	}
+	return nil
+}
+
+func (s *noopSender) SendResetEmail(toAddress string, data ResetData) error {
+	buf := &bytes.Buffer{}
+	if err := s.template.ExecuteTemplate(buf, resetTemplate, data); err != nil {
+		return err
+	}
+	resetBody := buf.String()
+
+	msg := assembleMessage(resetSubject, resetBody, toAddress, "test@example.org")
+
+	logrus.Tracef("NOT SENDING reset email to %s with contents: %s", toAddress, msg)
+
+	if s.sendCallback != nil {
+		s.sendCallback(toAddress, string(msg))
+	}
+
+	return nil
+}
diff --git a/internal/email/reset.go b/internal/email/reset.go
new file mode 100644
index 000000000..786777f1b
--- /dev/null
+++ b/internal/email/reset.go
@@ -0,0 +1,53 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package email
+
+import (
+	"bytes"
+	"net/smtp"
+)
+
+const (
+	resetTemplate = "email_reset.tmpl"
+	resetSubject  = "Subject: GoToSocial Password Reset"
+)
+
+func (s *sender) SendResetEmail(toAddress string, data ResetData) error {
+	buf := &bytes.Buffer{}
+	if err := s.template.ExecuteTemplate(buf, resetTemplate, data); err != nil {
+		return err
+	}
+	resetBody := buf.String()
+
+	msg := assembleMessage(resetSubject, resetBody, toAddress, s.from)
+	return smtp.SendMail(s.hostAddress, s.auth, s.from, []string{toAddress}, msg)
+}
+
+// ResetData represents data passed into the reset email address template.
+type ResetData struct {
+	// Username to be addressed.
+	Username string
+	// URL of the instance to present to the receiver.
+	InstanceURL string
+	// Name of the instance to present to the receiver.
+	InstanceName string
+	// Link to present to the receiver to click on and begin the reset process.
+	// Should be a full link with protocol eg., https://example.org/reset_password?token=some-reset-password-token
+	ResetLink string
+}
diff --git a/internal/email/sender.go b/internal/email/sender.go
new file mode 100644
index 000000000..a6a9abe55
--- /dev/null
+++ b/internal/email/sender.go
@@ -0,0 +1,60 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package email
+
+import (
+	"fmt"
+	"html/template"
+	"net/smtp"
+
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+)
+
+// Sender contains functions for sending emails to instance users/new signups.
+type Sender interface {
+	// SendConfirmEmail sends a 'please confirm your email' style email to the given toAddress, with the given data.
+	SendConfirmEmail(toAddress string, data ConfirmData) error
+
+	// SendResetEmail sends a 'reset your password' style email to the given toAddress, with the given data.
+	SendResetEmail(toAddress string, data ResetData) error
+}
+
+// NewSender returns a new email Sender interface with the given configuration, or an error if something goes wrong.
+func NewSender(cfg *config.Config) (Sender, error) {
+	t, err := loadTemplates(cfg.TemplateConfig.BaseDir)
+	if err != nil {
+		return nil, err
+	}
+
+	auth := smtp.PlainAuth("", cfg.SMTPConfig.Username, cfg.SMTPConfig.Password, cfg.SMTPConfig.Host)
+
+	return &sender{
+		hostAddress: fmt.Sprintf("%s:%d", cfg.SMTPConfig.Host, cfg.SMTPConfig.Port),
+		from:        cfg.SMTPConfig.From,
+		auth:        auth,
+		template:    t,
+	}, nil
+}
+
+type sender struct {
+	hostAddress string
+	from        string
+	auth        smtp.Auth
+	template    *template.Template
+}
diff --git a/internal/email/util.go b/internal/email/util.go
new file mode 100644
index 000000000..1d3db5802
--- /dev/null
+++ b/internal/email/util.go
@@ -0,0 +1,56 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package email
+
+import (
+	"fmt"
+	"html/template"
+	"os"
+	"path/filepath"
+)
+
+const (
+	mime = `MIME-version: 1.0;
+Content-Type: text/html;`
+)
+
+func loadTemplates(templateBaseDir string) (*template.Template, error) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		return nil, fmt.Errorf("error getting current working directory: %s", err)
+	}
+
+	// look for all templates that start with 'email_'
+	tmPath := filepath.Join(cwd, fmt.Sprintf("%semail_*", templateBaseDir))
+	return template.ParseGlob(tmPath)
+}
+
+func assembleMessage(mailSubject string, mailBody string, mailTo string, mailFrom string) []byte {
+	from := fmt.Sprintf("From: GoToSocial <%s>", mailFrom)
+	to := fmt.Sprintf("To: %s", mailTo)
+
+	msg := []byte(
+		mailSubject + "\r\n" +
+			from + "\r\n" +
+			to + "\r\n" +
+			mime + "\r\n" +
+			mailBody + "\r\n")
+
+	return msg
+}
diff --git a/internal/email/util_test.go b/internal/email/util_test.go
new file mode 100644
index 000000000..201bcd92d
--- /dev/null
+++ b/internal/email/util_test.go
@@ -0,0 +1,60 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package email_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/email"
+)
+
+type UtilTestSuite struct {
+	EmailTestSuite
+}
+
+func (suite *UtilTestSuite) TestTemplateConfirm() {
+	confirmData := email.ConfirmData{
+		Username:     "test",
+		InstanceURL:  "https://example.org",
+		InstanceName: "Test Instance",
+		ConfirmLink:  "https://example.org/confirm_email?token=ee24f71d-e615-43f9-afae-385c0799b7fa",
+	}
+
+	suite.sender.SendConfirmEmail("user@example.org", confirmData)
+	suite.Len(suite.sentEmails, 1)
+	suite.Equal("Subject: GoToSocial Email Confirmation\r\nFrom: GoToSocial <test@example.org>\r\nTo: user@example.org\r\nMIME-version: 1.0;\nContent-Type: text/html;\r\n<!DOCTYPE html>\n<html>\n    </head>\n    <body>\n        <div>\n            <h1>\n                Hello test!\n            </h1>\n        </div>\n        <div>\n            <p>\n                You are receiving this mail because you've requested an account on <a href=\"https://example.org\">Test Instance</a>.\n            </p>\n            <p>\n                We just need to confirm that this is your email address. To confirm your email, <a href=\"https://example.org/confirm_email?token=ee24f71d-e615-43f9-afae-385c0799b7fa\">click here</a> or paste the following in your browser's address bar:\n            </p>\n            <p>\n                <code>\n                    https://example.org/confirm_email?token=ee24f71d-e615-43f9-afae-385c0799b7fa\n                </code>\n            </p>\n        </div>\n        <div>\n            <p>\n                If you believe you've been sent this email in error, feel free to ignore it, or contact the administrator of <a href=\"https://example.org\">Test Instance</a>.\n            </p>\n        </div>\n    </body>\n</html>\r\n", suite.sentEmails["user@example.org"])
+}
+
+func (suite *UtilTestSuite) TestTemplateReset() {
+	resetData := email.ResetData{
+		Username:     "test",
+		InstanceURL:  "https://example.org",
+		InstanceName: "Test Instance",
+		ResetLink:    "https://example.org/reset_email?token=ee24f71d-e615-43f9-afae-385c0799b7fa",
+	}
+
+	suite.sender.SendResetEmail("user@example.org", resetData)
+	suite.Len(suite.sentEmails, 1)
+	suite.Equal("Subject: GoToSocial Password Reset\r\nFrom: GoToSocial <test@example.org>\r\nTo: user@example.org\r\nMIME-version: 1.0;\nContent-Type: text/html;\r\n<!DOCTYPE html>\n<html>\n    </head>\n    <body>\n        <div>\n            <h1>\n                Hello test!\n            </h1>\n        </div>\n        <div>\n            <p>\n                You are receiving this mail because a password reset has been requested for your account on <a href=\"https://example.org\">Test Instance</a>.\n            </p>\n            <p>\n                To reset your password, <a href=\"https://example.org/reset_email?token=ee24f71d-e615-43f9-afae-385c0799b7fa\">click here</a> or paste the following in your browser's address bar:\n            </p>\n            <p>\n                <code>\n                    https://example.org/reset_email?token=ee24f71d-e615-43f9-afae-385c0799b7fa\n                </code>\n            </p>\n        </div>\n        <div>\n            <p>\n                If you believe you've been sent this email in error, feel free to ignore it, or contact the administrator of <a href=\"https://example.org\">Test Instance</a>.\n            </p>\n        </div>\n    </body>\n</html>\r\n", suite.sentEmails["user@example.org"])
+}
+
+func TestUtilTestSuite(t *testing.T) {
+	suite.Run(t, &UtilTestSuite{})
+}