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...

4 Commits

Author SHA1 Message Date
peio
179866e6d3 feat: enhance logging and refactor database handling 2026-01-23 17:54:15 +00:00
peio
b067a23bba feature: switch to simple user 2026-01-21 22:54:20 +00:00
peio
7fdcc9fb10 feature: apps management 2026-01-21 22:53:57 +00:00
peio
9447523c6b Rename to mailcloak 2026-01-21 19:56:07 +00:00
24 changed files with 691 additions and 311 deletions

View File

@@ -22,7 +22,7 @@ jobs:
- name: Setup Go
uses: actions/setup-go@v5
with:
go-version: "1.22.x"
go-version: "1.25.x"
cache: true
- name: Build
@@ -34,22 +34,22 @@ jobs:
run: |
set -eux
mkdir -p dist
BIN="kc-policy-${GOOS}-${GOARCH}"
BIN="mailcloak-${GOOS}-${GOARCH}"
go build \
-trimpath \
-ldflags="-s -w -X main.version=${VERSION}" \
-o "dist/${BIN}" ./cmd/kc-policy
-o "dist/${BIN}" ./cmd/mailcloak
tar -C dist -czf "dist/${BIN}.tar.gz" "${BIN}"
cp aliasctl dist/
cp mailcloakctl dist/
sha256sum "dist/${BIN}.tar.gz" >> dist/checksums.txt
sha256sum "dist/aliasctl" >> dist/checksums.txt
sha256sum "dist/mailcloakctl" >> dist/checksums.txt
- name: Upload assets to Gitea release
uses: https://gitea.com/actions/gitea-release-action@v1
with:
files: |
dist/*.tar.gz
dist/aliasctl
dist/mailcloakctl
dist/checksums.txt
generate_release_notes: true
env:

View File

@@ -1,10 +1,11 @@
BINARY := kc-policy
BINARY := mailcloak
BIN_DIR := bin
.PHONY: build run test tidy clean install
build:
go build -o $(BIN_DIR)/$(BINARY) ./cmd/$(BINARY)
CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
go build -trimpath -ldflags="-s -w" -o bin/mailcloak ./cmd/mailcloak
run:
go run ./cmd/$(BINARY)

View File

@@ -1,4 +1,4 @@
# kc-policy
# mailcloak
Postfix policy + socketmap daemon that validates recipients/senders against Keycloak and serves a local aliases SQLite database.
@@ -9,13 +9,13 @@ Postfix policy + socketmap daemon that validates recipients/senders against Keyc
- **Socketmap service**: exposes an `alias` map to Postfix, rewriting alias -> `username@domain`.
## Project layout
- `cmd/kc-policy/` main package entrypoint
- `internal/kcpolicy/` daemon sources
- `cmd/mailcloak/` main package entrypoint
- `internal/mailcloak/` daemon sources
- `go.mod` / `go.sum` Go module files
- `configs/config.yaml.sample` sample config to copy to `/etc/kc-policy/config.yaml`
- `configs/openrc-kc-policy` OpenRC service file
- `configs/config.yaml.sample` sample config to copy to `/etc/mailcloak/config.yaml`
- `configs/openrc-mailcloak` OpenRC service file
- `db-init.sql` SQLite schema (also auto-created by the app)
- `aliasctl.py` CLI helper to manage aliases
- `mailcloakctl` CLI helper to manage aliases
## Build the binary
From the repository root:
@@ -40,8 +40,8 @@ make run
Copy the sample config and edit it:
```bash
install -d -m 0750 -o root -g postfix /etc/kc-policy
cp configs/config.yaml.sample /etc/kc-policy/config.yaml
install -d -m 0750 -o root -g postfix /etc/mailcloak
cp configs/config.yaml.sample /etc/mailcloak/config.yaml
```
Key settings:
@@ -50,34 +50,49 @@ Key settings:
- `sqlite.path` is the aliases database path.
- `sockets.*` must be under the Postfix chroot (usually `/var/spool/postfix`).
## Alias database
## Mailcloak database
### Aliases
You can manage aliases using the helper script:
```bash
./aliasctl.py --db /var/lib/kc-policy/aliases.db add alias@example.com username
./aliasctl.py --db /var/lib/kc-policy/aliases.db list
./mailcloakctl aliases add alias@example.com username
./mailcloakctl aliases list
```
The script creates the schema automatically if missing.
### Apps (Dovecot app passwords)
The helper script also manages application credentials. The application password is a token: updating the application ID and password is handled by the script and stored as a hash in SQLite. Dovecot can verify these credentials using plain authentication against the stored hash. Applications are restricted to sending emails only (they cannot receive them) and may use only their authorized sender addresses.
Examples:
```bash
./mailcloakctl apps add my-app-id "my-app-token"
./mailcloakctl apps allow my-app-id sender@example.com
./mailcloakctl apps list
./mailcloakctl apps disallow my-app-id sender@example.com
./mailcloakctl apps del my-app-id
```
## Postfix integration (example)
Policy service (smtpd_recipient_restrictions):
```
check_policy_service unix:private/kc-policy
check_policy_service unix:private/mailcloak
```
Socketmap (virtual_alias_maps):
```
socketmap:unix:private/kc-socketmap:alias
socketmap:unix:private/mailcloak-socketmap:alias
```
## OpenRC
Use the provided service file:
```bash
cp configs/openrc-kc-policy /etc/init.d/kc-policy
rc-update add kc-policy default
rc-service kc-policy start
cp configs/openrc-mailcloak /etc/init.d/mailcloak
rc-update add mailcloak default
rc-service mailcloak start
```
## Notes

View File

@@ -1,96 +0,0 @@
#!/usr/bin/env python3
import argparse
import sqlite3
import time
import sys
DEFAULT_DB = "/var/lib/kc-policy/aliases.db"
SCHEMA = """
CREATE TABLE IF NOT EXISTS aliases (
alias_email TEXT PRIMARY KEY,
username TEXT NOT NULL,
enabled INTEGER NOT NULL DEFAULT 1,
updated_at INTEGER NOT NULL DEFAULT (strftime('%s','now'))
);
CREATE INDEX IF NOT EXISTS idx_aliases_username ON aliases(username);
"""
def connect(db_path: str):
con = sqlite3.connect(db_path)
con.execute("PRAGMA journal_mode=WAL;")
con.execute("PRAGMA synchronous=NORMAL;")
con.executescript(SCHEMA)
return con
def norm_email(s: str) -> str:
return s.strip().lower()
def cmd_add(con, alias_email, username):
alias_email = norm_email(alias_email)
username = username.strip()
now = int(time.time())
con.execute(
"INSERT INTO aliases(alias_email, username, enabled, updated_at) VALUES(?,?,1,?) "
"ON CONFLICT(alias_email) DO UPDATE SET username=excluded.username, enabled=1, updated_at=excluded.updated_at",
(alias_email, username, now),
)
con.commit()
def cmd_del(con, alias_email):
alias_email = norm_email(alias_email)
con.execute("DELETE FROM aliases WHERE alias_email=?", (alias_email,))
con.commit()
def cmd_disable(con, alias_email):
alias_email = norm_email(alias_email)
con.execute("UPDATE aliases SET enabled=0, updated_at=? WHERE alias_email=?", (int(time.time()), alias_email))
con.commit()
def cmd_list(con, username=None):
if username:
rows = con.execute(
"SELECT alias_email, username, enabled, updated_at FROM aliases WHERE username=? ORDER BY alias_email",
(username,),
).fetchall()
else:
rows = con.execute(
"SELECT alias_email, username, enabled, updated_at FROM aliases ORDER BY username, alias_email"
).fetchall()
for a,u,en,ts in rows:
print(f"{a}\t{u}\t{'enabled' if en else 'disabled'}\t{ts}")
def main():
ap = argparse.ArgumentParser()
ap.add_argument("--db", default=DEFAULT_DB)
sub = ap.add_subparsers(dest="cmd", required=True)
p_add = sub.add_parser("add")
p_add.add_argument("alias_email")
p_add.add_argument("username")
p_del = sub.add_parser("del")
p_del.add_argument("alias_email")
p_dis = sub.add_parser("disable")
p_dis.add_argument("alias_email")
p_ls = sub.add_parser("list")
p_ls.add_argument("--user", default=None)
args = ap.parse_args()
con = connect(args.db)
try:
if args.cmd == "add":
cmd_add(con, args.alias_email, args.username)
elif args.cmd == "del":
cmd_del(con, args.alias_email)
elif args.cmd == "disable":
cmd_disable(con, args.alias_email)
elif args.cmd == "list":
cmd_list(con, args.user)
finally:
con.close()
if __name__ == "__main__":
sys.exit(main())

View File

@@ -1,68 +0,0 @@
package main
import (
"context"
"fmt"
"log"
"os"
"os/signal"
"syscall"
"time"
"kc-policy/internal/kcpolicy"
)
var version = "dev"
func main() {
if len(os.Args) > 1 && os.Args[1] == "--version" {
fmt.Println(version)
return
}
cfgPath := "/etc/kc-policy/config.yaml"
if len(os.Args) >= 2 {
cfgPath = os.Args[1]
}
cfg, err := kcpolicy.LoadConfig(cfgPath)
if err != nil {
log.Fatalf("config: %v", err)
}
db, err := kcpolicy.OpenAliasDB(cfg.SQLite.Path)
if err != nil {
log.Fatalf("sqlite: %v", err)
}
defer db.Close()
kc := kcpolicy.NewKeycloak(cfg)
cache := kcpolicy.NewCache(time.Duration(cfg.Policy.CacheTTLSeconds) * time.Second)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
// Start socketmap server
go func() {
if err := kcpolicy.RunSocketmap(ctx, cfg, db); err != nil {
log.Fatalf("socketmap: %v", err)
}
}()
// Start policy server
go func() {
if err := kcpolicy.RunPolicy(ctx, cfg, db, kc, cache); err != nil {
log.Fatalf("policy: %v", err)
}
}()
log.Printf("kc-policy started")
// Handle signals
ch := make(chan os.Signal, 2)
signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
<-ch
log.Printf("shutdown")
cancel()
time.Sleep(300 * time.Millisecond)
}

92
cmd/mailcloak/main.go Normal file
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@@ -0,0 +1,92 @@
package main
import (
"context"
"fmt"
"log"
"os"
"os/signal"
"syscall"
"time"
"mailcloak/internal/mailcloak"
)
var version = "dev"
func main() {
fmt.Printf("mailcloak %s\n", version)
if len(os.Args) > 1 && os.Args[1] == "--version" {
return
}
cfgPath := "/etc/mailcloak/config.yaml"
if len(os.Args) >= 2 {
cfgPath = os.Args[1]
}
log.Printf("loading config from %s", cfgPath)
cfg, err := mailcloak.LoadConfig(cfgPath)
if err != nil {
log.Fatalf("config: %v", err)
}
log.Printf("opening policy listener at %s", cfg.Sockets.PolicySocket)
policyListener, err := mailcloak.OpenPolicyListener(cfg)
if err != nil {
log.Fatalf("policy listener: %v", err)
}
log.Printf("opening socketmap listener at %s", cfg.Sockets.SocketmapSocket)
socketmapListener, err := mailcloak.OpenSocketmapListener(cfg)
if err != nil {
_ = policyListener.Close()
log.Fatalf("socketmap listener: %v", err)
}
log.Printf("dropping privileges to %s", cfg.Daemon.User)
if err := mailcloak.DropPrivileges(cfg); err != nil {
_ = policyListener.Close()
_ = socketmapListener.Close()
log.Fatalf("privileges: %v", err)
}
log.Printf("opening sqlite db at %s", cfg.SQLite.Path)
db, err := mailcloak.OpenMailcloakDB(cfg.SQLite.Path)
if err != nil {
log.Fatalf("sqlite: %v", err)
}
defer db.Close()
kc := mailcloak.NewKeycloak(cfg)
cache := mailcloak.NewCache(time.Duration(cfg.Policy.CacheTTLSeconds) * time.Second)
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
// Start socketmap server
go func() {
log.Printf("socketmap server started")
if err := mailcloak.ServeSocketmap(ctx, cfg, db, socketmapListener); err != nil {
log.Fatalf("socketmap: %v", err)
}
}()
// Start policy server
go func() {
log.Printf("policy server started")
if err := mailcloak.ServePolicy(ctx, cfg, db, kc, cache, policyListener); err != nil {
log.Fatalf("policy: %v", err)
}
}()
log.Printf("mailcloak started")
// Handle signals
ch := make(chan os.Signal, 2)
signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM)
<-ch
log.Printf("shutdown")
cancel()
time.Sleep(300 * time.Millisecond)
}

View File

@@ -6,7 +6,7 @@ keycloak:
# admin API is derived: {base_url}/admin/realms/{realm}
sqlite:
path: "/var/lib/kc-policy/aliases.db"
path: "/var/lib/mailcloak/state.db"
policy:
domain: "<EMail domain-name>"
@@ -19,8 +19,11 @@ policy:
sockets:
# These paths must be inside postfix chroot (/var/spool/postfix)
policy_socket: "/var/spool/postfix/private/kc-policy"
socketmap_socket: "/var/spool/postfix/private/kc-socketmap"
policy_socket: "/var/spool/postfix/private/mailcloak-policy"
socketmap_socket: "/var/spool/postfix/private/mailcloak-socketmap"
socket_owner_user: "postfix"
socket_owner_group: "postfix"
socket_mode: "0660"
daemon:
user: "mailcloak"

View File

@@ -1,23 +0,0 @@
#!/sbin/openrc-run
name="kc-policy"
command="/usr/local/sbin/kc-policy"
command_args="/etc/kc-policy/config.yaml"
command_background="yes"
pidfile="/run/kc-policy.pid"
depend() {
need net
after postfix
}
start_pre() {
checkpath -d -m 0750 -o root:postfix /etc/kc-policy
checkpath -d -m 0750 -o root:postfix /var/lib/kc-policy
checkpath -d -m 0755 -o root:root /usr/local/sbin
# sockets dir already exists
}
stop_post() {
rm -f /var/spool/postfix/private/kc-policy /var/spool/postfix/private/kc-socketmap
}

21
configs/openrc-mailcloak Normal file
View File

@@ -0,0 +1,21 @@
#!/sbin/openrc-run
name="mailcloak"
command="/usr/local/sbin/mailcloak"
command_args="/etc/mailcloak/config.yaml"
command_background="yes"
pidfile="/run/mailcloak.pid"
depend() {
need net
after postfix
}
start_pre() {
checkpath -d -m 0750 -o root:root /etc/mailcloak
checkpath -d -m 0750 -o mailcloak:dovecot /var/lib/mailcloak
}
stop_post() {
rm -f /var/spool/postfix/private/mailcloak-policy /var/spool/postfix/private/mailcloak-socketmap
}

View File

@@ -9,7 +9,7 @@ virtual_mailbox_domains = static:<EMail domain-name>
virtual_transport = lmtp:unix:private/dovecot-lmtp
# Dynamic aliases via socketmap
virtual_alias_maps = socketmap:unix:private/kc-socketmap:alias
virtual_alias_maps = socketmap:unix:private/mailcloak-socketmap:alias
# Policy (RCPT existence + sender policy on 587 via master.cf)
smtpd_recipient_restrictions =
@@ -17,5 +17,5 @@ smtpd_recipient_restrictions =
reject_unknown_recipient_domain,
permit_sasl_authenticated,
reject_unauth_destination,
check_policy_service unix:private/kc-policy,
check_policy_service unix:private/mailcloak-policy,
permit

View File

@@ -2,7 +2,7 @@
# Configuration to add to /etc/postfix/master.cf
#
-o smtpd_sender_restrictions=check_policy_service unix:private/kc-policy
-o smtpd_sender_restrictions=check_policy_service unix:private/mailcloak-policy
# You can remove `reject_senders_login_mismaych` + `sender_login_maps`
# as this kc-policy will handle it.
# You can remove `reject_senders_login_mismatch` + `sender_login_maps`
# as mailcloak will handle it.

View File

@@ -1,8 +0,0 @@
CREATE TABLE IF NOT EXISTS aliases (
alias_email TEXT PRIMARY KEY,
username TEXT NOT NULL,
enabled INTEGER NOT NULL DEFAULT 1,
updated_at INTEGER NOT NULL DEFAULT (strftime('%s','now'))
);
CREATE INDEX IF NOT EXISTS idx_aliases_username ON aliases(username);

2
go.mod
View File

@@ -1,4 +1,4 @@
module kc-policy
module mailcloak
go 1.22

View File

@@ -1,62 +0,0 @@
package kcpolicy
import (
"database/sql"
"fmt"
_ "modernc.org/sqlite"
)
type AliasDB struct{ DB *sql.DB }
func OpenAliasDB(path string) (*AliasDB, error) {
db, err := sql.Open("sqlite", path)
if err != nil {
return nil, err
}
if _, err := db.Exec(`
CREATE TABLE IF NOT EXISTS aliases (
alias_email TEXT PRIMARY KEY,
username TEXT NOT NULL,
enabled INTEGER NOT NULL DEFAULT 1,
updated_at INTEGER NOT NULL DEFAULT (strftime('%s','now'))
);
CREATE INDEX IF NOT EXISTS idx_aliases_username ON aliases(username);
`); err != nil {
_ = db.Close()
return nil, fmt.Errorf("init schema: %w", err)
}
return &AliasDB{DB: db}, nil
}
func (a *AliasDB) Close() error { return a.DB.Close() }
// Returns username owning alias, ok
func (a *AliasDB) AliasOwner(aliasEmail string) (string, bool, error) {
var username string
var enabled int
err := a.DB.QueryRow(`SELECT username, enabled FROM aliases WHERE alias_email=?`, aliasEmail).Scan(&username, &enabled)
if err == sql.ErrNoRows {
return "", false, nil
}
if err != nil {
return "", false, err
}
if enabled != 1 {
return "", false, nil
}
return username, true, nil
}
// Returns true if alias belongs to username
func (a *AliasDB) AliasBelongsTo(aliasEmail, username string) (bool, error) {
var enabled int
err := a.DB.QueryRow(`SELECT enabled FROM aliases WHERE alias_email=? AND username=?`, aliasEmail, username).Scan(&enabled)
if err == sql.ErrNoRows {
return false, nil
}
if err != nil {
return false, err
}
return enabled == 1, nil
}

View File

@@ -1,13 +1,18 @@
package kcpolicy
package mailcloak
import (
"fmt"
"log"
"os"
"gopkg.in/yaml.v3"
)
type Config struct {
Daemon struct {
User string `yaml:"user"`
} `yaml:"daemon"`
Keycloak struct {
BaseURL string `yaml:"base_url"`
Realm string `yaml:"realm"`
@@ -54,9 +59,15 @@ func LoadConfig(path string) (*Config, error) {
}
if cfg.Policy.CacheTTLSeconds <= 0 {
cfg.Policy.CacheTTLSeconds = 120
log.Printf("config: policy.cache_ttl_seconds not set, defaulting to %d", cfg.Policy.CacheTTLSeconds)
}
if cfg.Policy.KeycloakFailureMode == "" {
cfg.Policy.KeycloakFailureMode = "tempfail"
log.Printf("config: policy.keycloak_failure_mode not set, defaulting to %s", cfg.Policy.KeycloakFailureMode)
}
if cfg.Daemon.User == "" {
cfg.Daemon.User = "mailcloak"
log.Printf("config: daemon.user not set, defaulting to %s", cfg.Daemon.User)
}
return &cfg, nil
}

View File

@@ -1,10 +1,11 @@
package kcpolicy
package mailcloak
import (
"context"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"net/url"
"strings"
@@ -43,18 +44,22 @@ func (k *Keycloak) token(ctx context.Context) (string, error) {
resp, err := k.hc.Do(req)
if err != nil {
log.Printf("keycloak token request error: %v", err)
return "", err
}
defer resp.Body.Close()
if resp.StatusCode/100 != 2 {
b, _ := io.ReadAll(io.LimitReader(resp.Body, 2048))
log.Printf("keycloak token non-2xx: %d", resp.StatusCode)
return "", fmt.Errorf("token http %d: %s", resp.StatusCode, string(b))
}
var tr tokenResp
if err := json.NewDecoder(resp.Body).Decode(&tr); err != nil {
log.Printf("keycloak token decode error: %v", err)
return "", err
}
if tr.AccessToken == "" {
log.Printf("keycloak token response missing access_token")
return "", fmt.Errorf("empty access_token")
}
return tr.AccessToken, nil
@@ -82,15 +87,18 @@ func (k *Keycloak) adminGet(ctx context.Context, bearer, path string, q url.Valu
resp, err := k.hc.Do(req)
if err != nil {
log.Printf("keycloak admin request error: %v", err)
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode/100 != 2 {
b, _ := io.ReadAll(io.LimitReader(resp.Body, 2048))
log.Printf("keycloak admin non-2xx: %d", resp.StatusCode)
return nil, fmt.Errorf("admin http %d: %s", resp.StatusCode, string(b))
}
var users []kcUser
if err := json.NewDecoder(resp.Body).Decode(&users); err != nil {
log.Printf("keycloak admin decode error: %v", err)
return nil, err
}
return users, nil
@@ -108,11 +116,13 @@ func (k *Keycloak) EmailByUsername(ctx context.Context, username string) (string
q.Set("exact", "true")
users, err := k.adminGet(ctx, bearer, "/users", q)
if err != nil {
log.Printf("keycloak admin exact username lookup failed for %s: %v", username, err)
// fallback: search
q2 := url.Values{}
q2.Set("search", username)
users, err = k.adminGet(ctx, bearer, "/users", q2)
if err != nil {
log.Printf("keycloak admin search username lookup failed for %s: %v", username, err)
return "", false, err
}
}
@@ -136,11 +146,13 @@ func (k *Keycloak) EmailExists(ctx context.Context, email string) (bool, error)
q.Set("exact", "true")
users, err := k.adminGet(ctx, bearer, "/users", q)
if err != nil {
log.Printf("keycloak admin exact email lookup failed for %s: %v", email, err)
// fallback: search
q2 := url.Values{}
q2.Set("search", email)
users, err = k.adminGet(ctx, bearer, "/users", q2)
if err != nil {
log.Printf("keycloak admin search email lookup failed for %s: %v", email, err)
return false, err
}
}

View File

@@ -1,4 +1,4 @@
package kcpolicy
package mailcloak
import (
"bufio"
@@ -38,19 +38,26 @@ func (c *Cache) Put(key, val string, ok bool) {
c.m[key] = cacheItem{val: val, ok: ok, expires: time.Now().Add(c.ttl)}
}
func RunPolicy(ctx context.Context, cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache) error {
func OpenPolicyListener(cfg *Config) (net.Listener, error) {
sock := cfg.Sockets.PolicySocket
_ = os.Remove(sock)
l, err := net.Listen("unix", sock)
if err != nil {
return err
return nil, err
}
defer l.Close()
if err := ChownChmodSocket(sock, cfg); err != nil {
return err
_ = l.Close()
return nil, err
}
log.Printf("policy listener ready on %s", sock)
return l, nil
}
func ServePolicy(ctx context.Context, cfg *Config, db *MailcloakDB, kc *Keycloak, cache *Cache, l net.Listener) error {
defer l.Close()
for {
conn, err := l.Accept()
@@ -59,6 +66,7 @@ func RunPolicy(ctx context.Context, cfg *Config, db *AliasDB, kc *Keycloak, cach
case <-ctx.Done():
return nil
default:
log.Printf("policy accept error: %v", err)
return err
}
}
@@ -66,7 +74,15 @@ func RunPolicy(ctx context.Context, cfg *Config, db *AliasDB, kc *Keycloak, cach
}
}
func handlePolicyConn(conn net.Conn, cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache) {
func RunPolicy(ctx context.Context, cfg *Config, db *MailcloakDB, kc *Keycloak, cache *Cache) error {
l, err := OpenPolicyListener(cfg)
if err != nil {
return err
}
return ServePolicy(ctx, cfg, db, kc, cache, l)
}
func handlePolicyConn(conn net.Conn, cfg *Config, db *MailcloakDB, kc *Keycloak, cache *Cache) {
defer conn.Close()
r := bufio.NewReader(conn)
@@ -85,6 +101,8 @@ func handlePolicyConn(conn net.Conn, cfg *Config, db *AliasDB, kc *Keycloak, cac
}
}
log.Printf("policy request: state=%s sasl=%s sender=%s rcpt=%s client=%s helo=%s", req["protocol_state"], req["sasl_username"], req["sender"], req["recipient"], req["client_address"], req["helo_name"])
// Decide based on protocol_state
state := req["protocol_state"] // e.g. RCPT, MAIL
saslUser := req["sasl_username"]
@@ -96,19 +114,28 @@ func handlePolicyConn(conn net.Conn, cfg *Config, db *AliasDB, kc *Keycloak, cac
switch state {
case "RCPT":
action = policyRCPT(cfg, db, kc, cache, rcpt)
case "MAIL":
// On MAIL stage we can validate sender if authenticated (submission)
if saslUser != "" && sender != "" {
if action == "DUNNO" {
action = policyMAIL(cfg, db, kc, cache, saslUser, sender)
}
case "MAIL":
// With "smtpd_delay_reject = yes" in Postfix, MAIL stage is bypassed
// So we move all checks to RCPT stage
action = "DUNNO"
// On MAIL stage we can validate sender if authenticated (submission)
//if saslUser != "" && sender != "" {
// action = policyMAIL(cfg, db, kc, cache, saslUser, sender)
//}
default:
action = "DUNNO"
}
log.Printf("policy decision: state=%s action=%s sasl=%s sender=%s rcpt=%s", state, action, saslUser, sender, rcpt)
fmt.Fprintf(conn, "action=%s\n\n", action)
}
func policyRCPT(cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache, rcpt string) string {
func policyRCPT(cfg *Config, db *MailcloakDB, kc *Keycloak, cache *Cache, rcpt string) string {
if rcpt == "" {
return "DUNNO"
}
@@ -128,6 +155,7 @@ func policyRCPT(cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache, rcpt strin
defer cancel()
exists, err := kc.EmailExists(ctx, rcpt)
if err != nil {
log.Printf("keycloak email exists lookup error for %s: %v", rcpt, err)
if cfg.Policy.KeycloakFailureMode == "dunno" {
return "DUNNO"
}
@@ -152,7 +180,7 @@ func policyRCPT(cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache, rcpt strin
return "550 5.1.1 No such user"
}
func policyMAIL(cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache, saslUser, sender string) string {
func policyMAIL(cfg *Config, db *MailcloakDB, kc *Keycloak, cache *Cache, saslUser, sender string) string {
// Allow empty sender (bounce)
if sender == "" || sender == "<>" {
return "DUNNO"
@@ -170,6 +198,7 @@ func policyMAIL(cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache, saslUser,
defer cancel()
e, exists, err := kc.EmailByUsername(ctx, saslUser)
if err != nil {
log.Printf("keycloak email-by-username lookup error for %s: %v", saslUser, err)
if cfg.Policy.KeycloakFailureMode == "dunno" {
return "DUNNO"
}
@@ -194,5 +223,17 @@ func policyMAIL(cfg *Config, db *AliasDB, kc *Keycloak, cache *Cache, saslUser,
return "DUNNO"
}
// 3) sender is allowed for app (saslUser = app_id)
if saslUser != "" {
allowed, err := db.AppFromAllowed(saslUser, sender)
if err != nil {
log.Printf("sqlite app sender lookup error: %v", err)
return "451 4.3.0 Temporary internal error"
}
if allowed {
return "DUNNO"
}
}
return "553 5.7.1 Sender not owned by authenticated user"
}

View File

@@ -0,0 +1,64 @@
package mailcloak
import (
"fmt"
"log"
"os"
"os/user"
"strconv"
"syscall"
)
func DropPrivileges(cfg *Config) error {
userName := cfg.Daemon.User
if userName == "" {
userName = "mailcloak"
}
u, err := user.Lookup(userName)
if err != nil {
return fmt.Errorf("lookup user %s: %w", userName, err)
}
uid, err := strconv.Atoi(u.Uid)
if err != nil {
return fmt.Errorf("bad uid for %s: %w", userName, err)
}
gid, err := strconv.Atoi(u.Gid)
if err != nil {
return fmt.Errorf("bad gid for %s: %w", userName, err)
}
euid := os.Geteuid()
if euid == uid {
log.Printf("privileges: already running as %s", userName)
return nil
}
if euid != 0 {
return fmt.Errorf("must run as root to switch user to %s", userName)
}
if groups, err := u.GroupIds(); err == nil {
gids := make([]int, 0, len(groups))
for _, g := range groups {
if id, err := strconv.Atoi(g); err == nil {
gids = append(gids, id)
}
}
if len(gids) > 0 {
if err := syscall.Setgroups(gids); err != nil {
return fmt.Errorf("setgroups: %w", err)
}
}
}
if err := syscall.Setgid(gid); err != nil {
return fmt.Errorf("setgid: %w", err)
}
if err := syscall.Setuid(uid); err != nil {
return fmt.Errorf("setuid: %w", err)
}
log.Printf("privileges: dropped to %s (uid=%d gid=%d)", userName, uid, gid)
return nil
}

View File

@@ -1,7 +1,8 @@
package kcpolicy
package mailcloak
import (
"fmt"
"log"
"os"
"os/user"
"strconv"
@@ -27,5 +28,6 @@ func ChownChmodSocket(path string, cfg *Config) error {
if err != nil {
return fmt.Errorf("bad socket_mode: %w", err)
}
log.Printf("socket perms: chown %s:%s mode %s on %s", cfg.Sockets.SocketOwnerUser, cfg.Sockets.SocketOwnerGroup, cfg.Sockets.SocketMode, path)
return os.Chmod(path, os.FileMode(mode))
}

View File

@@ -1,29 +1,38 @@
package kcpolicy
package mailcloak
import (
"bufio"
"context"
"errors"
"fmt"
"io"
"log"
"net"
"os"
"strconv"
"strings"
)
func RunSocketmap(ctx context.Context, cfg *Config, db *AliasDB) error {
func OpenSocketmapListener(cfg *Config) (net.Listener, error) {
sock := cfg.Sockets.SocketmapSocket
_ = os.Remove(sock)
l, err := net.Listen("unix", sock)
if err != nil {
return err
return nil, err
}
defer l.Close()
if err := ChownChmodSocket(sock, cfg); err != nil {
return err
_ = l.Close()
return nil, err
}
log.Printf("socketmap listener ready on %s", sock)
return l, nil
}
func ServeSocketmap(ctx context.Context, cfg *Config, db *MailcloakDB, l net.Listener) error {
defer l.Close()
for {
conn, err := l.Accept()
@@ -32,6 +41,7 @@ func RunSocketmap(ctx context.Context, cfg *Config, db *AliasDB) error {
case <-ctx.Done():
return nil
default:
log.Printf("socketmap accept error: %v", err)
return err
}
}
@@ -39,34 +49,49 @@ func RunSocketmap(ctx context.Context, cfg *Config, db *AliasDB) error {
}
}
func RunSocketmap(ctx context.Context, cfg *Config, db *MailcloakDB) error {
l, err := OpenSocketmapListener(cfg)
if err != nil {
return err
}
return ServeSocketmap(ctx, cfg, db, l)
}
// Postfix socketmap framing: "<len>:<payload>,"
func handleSocketmapConn(conn net.Conn, cfg *Config, db *AliasDB) {
func handleSocketmapConn(conn net.Conn, cfg *Config, db *MailcloakDB) {
defer conn.Close()
r := bufio.NewReader(conn)
for {
payload, err := readSocketmapFrame(r)
if err != nil {
if !errors.Is(err, io.EOF) && !errors.Is(err, io.ErrUnexpectedEOF) {
log.Printf("socketmap read error: %v", err)
}
// normal close
return
}
payload = strings.TrimSpace(payload)
if payload == "" {
log.Printf("socketmap request: empty payload")
_ = writeSocketmapFrame(conn, "NOTFOUND")
continue
}
parts := strings.SplitN(payload, " ", 2)
if len(parts) != 2 {
log.Printf("socketmap request: malformed payload=%q", payload)
_ = writeSocketmapFrame(conn, "TEMP")
continue
}
mapName := parts[0]
key := strings.ToLower(strings.TrimSpace(parts[1]))
log.Printf("socketmap request: map=%s key=%s", mapName, key)
if mapName != "alias" {
log.Printf("socketmap decision: map=%s action=NOTFOUND", mapName)
_ = writeSocketmapFrame(conn, "NOTFOUND")
continue
}
@@ -74,22 +99,27 @@ func handleSocketmapConn(conn net.Conn, cfg *Config, db *AliasDB) {
// Only handle our domain
domain := strings.ToLower(cfg.Policy.Domain)
if !strings.HasSuffix(key, "@"+domain) {
log.Printf("socketmap decision: map=alias key=%s action=NOTFOUND (other domain)", key)
_ = writeSocketmapFrame(conn, "NOTFOUND")
continue
}
username, ok, err := db.AliasOwner(key)
if err != nil {
log.Printf("socketmap db error: key=%s err=%v", key, err)
_ = writeSocketmapFrame(conn, "TEMP")
continue
}
if !ok {
log.Printf("socketmap decision: map=alias key=%s action=NOTFOUND", key)
_ = writeSocketmapFrame(conn, "NOTFOUND")
continue
}
// rewrite alias -> username@domain
_ = writeSocketmapFrame(conn, fmt.Sprintf("OK %s@%s", username, domain))
reply := fmt.Sprintf("OK %s@%s", username, domain)
log.Printf("socketmap decision: map=alias key=%s action=%s", key, reply)
_ = writeSocketmapFrame(conn, reply)
}
}

View File

@@ -0,0 +1,119 @@
package mailcloak
import (
"database/sql"
"fmt"
"log"
"os"
"path/filepath"
"strings"
_ "modernc.org/sqlite"
)
type MailcloakDB struct{ DB *sql.DB }
func OpenMailcloakDB(path string) (*MailcloakDB, error) {
log.Printf("sqlite: opening db at %s", path)
if err := ensureDBExists(path); err != nil {
return nil, err
}
db, err := sql.Open("sqlite", path)
if err != nil {
return nil, err
}
if _, err := db.Exec(`
PRAGMA foreign_keys=ON;
PRAGMA journal_mode=WAL;
PRAGMA synchronous=NORMAL;
`); err != nil {
_ = db.Close()
return nil, fmt.Errorf("init pragmas: %w", err)
}
log.Printf("sqlite: db ready")
return &MailcloakDB{DB: db}, nil
}
func (a *MailcloakDB) Close() error { return a.DB.Close() }
// Returns username owning alias, ok
func (a *MailcloakDB) AliasOwner(aliasEmail string) (string, bool, error) {
var username string
var enabled int
err := a.DB.QueryRow(`SELECT username, enabled FROM aliases WHERE alias_email=?`, aliasEmail).Scan(&username, &enabled)
if err == sql.ErrNoRows {
return "", false, nil
}
if err != nil {
return "", false, err
}
if enabled != 1 {
return "", false, nil
}
return username, true, nil
}
// Returns true if alias belongs to username
func (a *MailcloakDB) AliasBelongsTo(aliasEmail, username string) (bool, error) {
var enabled int
err := a.DB.QueryRow(`SELECT enabled FROM aliases WHERE alias_email=? AND username=?`, aliasEmail, username).Scan(&enabled)
if err == sql.ErrNoRows {
return false, nil
}
if err != nil {
return false, err
}
return enabled == 1, nil
}
// Returns true if app_id is enabled and sender is allowed for app
func (a *MailcloakDB) AppFromAllowed(appID, fromAddr string) (bool, error) {
var appEnabled int
var fromEnabled int
err := a.DB.QueryRow(`
SELECT a.enabled, af.enabled
FROM app_from af
JOIN apps a ON a.app_id = af.app_id
WHERE af.app_id=? AND af.from_addr=?`, appID, fromAddr).Scan(&appEnabled, &fromEnabled)
if err == sql.ErrNoRows {
return false, nil
}
if err != nil {
return false, err
}
return appEnabled == 1 && fromEnabled == 1, nil
}
func ensureDBExists(path string) error {
if path == ":memory:" || strings.HasPrefix(path, "file:") {
return nil
}
if path == "" {
return fmt.Errorf("sqlite path is empty")
}
dir := filepath.Dir(path)
if dir == "." || dir == "" {
if _, err := os.Stat(path); err != nil {
if os.IsNotExist(err) {
return fmt.Errorf("sqlite db not found at %s; create it with 'mailcloakctl init'", path)
}
return err
}
return nil
}
if _, err := os.Stat(dir); err != nil {
if os.IsNotExist(err) {
return fmt.Errorf("sqlite db directory not found at %s; create the db with 'mailcloakctl init'", dir)
}
return err
}
if _, err := os.Stat(path); err != nil {
if os.IsNotExist(err) {
return fmt.Errorf("sqlite db not found at %s; create it with 'mailcloakctl init'", path)
}
return err
}
return nil
}

225
mailcloakctl Executable file
View File

@@ -0,0 +1,225 @@
#!/usr/bin/env python3
import argparse
import sqlite3
import time
import sys
from argon2 import PasswordHasher, Type
from pathlib import Path
DEFAULT_DB = "/var/lib/mailcloak/state.db"
def connect(db_path: str, create: bool = False):
db_file = Path(db_path).expanduser().resolve()
if not create and not db_file.exists():
raise SystemExit(f"sqlite db not found at {db_file}; create it with mailcloakctl init")
if create:
db_file.parent.mkdir(parents=True, exist_ok=True)
con = sqlite3.connect(str(db_file))
con.execute("PRAGMA foreign_keys=ON;")
con.execute("PRAGMA journal_mode=WAL;")
con.execute("PRAGMA synchronous=NORMAL;")
con.executescript("""
CREATE TABLE IF NOT EXISTS aliases (
alias_email TEXT PRIMARY KEY,
username TEXT NOT NULL,
enabled INTEGER NOT NULL DEFAULT 1,
updated_at INTEGER NOT NULL DEFAULT (strftime('%s','now'))
);
CREATE INDEX IF NOT EXISTS idx_aliases_username ON aliases(username);
CREATE TABLE IF NOT EXISTS apps (
app_id TEXT PRIMARY KEY,
secret_hash TEXT NOT NULL,
enabled INTEGER NOT NULL DEFAULT 1,
created_at INTEGER NOT NULL
);
CREATE TABLE IF NOT EXISTS app_from (
app_id TEXT NOT NULL,
from_addr TEXT NOT NULL,
enabled INTEGER NOT NULL DEFAULT 1,
PRIMARY KEY (app_id, from_addr),
FOREIGN KEY (app_id) REFERENCES apps(app_id) ON DELETE CASCADE
);
"""
)
return con
def norm_email(s: str) -> str:
return s.strip().lower()
def norm_id(s: str) -> str:
return s.strip()
argon2_hasher = PasswordHasher(
time_cost=3,
memory_cost=65536,
parallelism=1,
hash_len=32,
salt_len=16,
type=Type.ID,
)
def cmd_aliases_add(con, alias_email, username):
alias_email = norm_email(alias_email)
username = username.strip()
now = int(time.time())
con.execute(
"INSERT INTO aliases(alias_email, username, enabled, updated_at) VALUES(?,?,1,?) "
"ON CONFLICT(alias_email) DO UPDATE SET username=excluded.username, enabled=1, updated_at=excluded.updated_at",
(alias_email, username, now),
)
con.commit()
def cmd_aliases_del(con, alias_email):
alias_email = norm_email(alias_email)
con.execute("DELETE FROM aliases WHERE alias_email=?", (alias_email,))
con.commit()
def cmd_aliases_disable(con, alias_email):
alias_email = norm_email(alias_email)
con.execute("UPDATE aliases SET enabled=0, updated_at=? WHERE alias_email=?", (int(time.time()), alias_email))
con.commit()
def cmd_aliases_list(con, username=None):
if username:
rows = con.execute(
"SELECT alias_email, username, enabled, updated_at FROM aliases WHERE username=? ORDER BY alias_email",
(username,),
).fetchall()
else:
rows = con.execute(
"SELECT alias_email, username, enabled, updated_at FROM aliases ORDER BY username, alias_email"
).fetchall()
for a,u,en,ts in rows:
print(f"{a}\t{u}\t{'enabled' if en else 'disabled'}\t{ts}")
def cmd_apps_add(con, app_id, password):
app_id = norm_id(app_id)
secret_hash = f"{{ARGON2ID}}{argon2_hasher.hash(password)}"
now = int(time.time())
con.execute(
"INSERT INTO apps(app_id, secret_hash, enabled, created_at) VALUES(?,?,1,?) "
"ON CONFLICT(app_id) DO UPDATE SET secret_hash=excluded.secret_hash, enabled=1, created_at=excluded.created_at",
(app_id, secret_hash, now),
)
con.commit()
def cmd_apps_del(con, app_id):
app_id = norm_id(app_id)
con.execute("DELETE FROM apps WHERE app_id=?", (app_id,))
con.commit()
def cmd_apps_allow(con, app_id, from_addr):
app_id = norm_id(app_id)
from_addr = norm_email(from_addr)
con.execute(
"INSERT INTO app_from(app_id, from_addr, enabled) VALUES(?,?,1) "
"ON CONFLICT(app_id, from_addr) DO UPDATE SET enabled=1",
(app_id, from_addr),
)
con.commit()
def cmd_apps_disallow(con, app_id, from_addr):
app_id = norm_id(app_id)
from_addr = norm_email(from_addr)
con.execute("DELETE FROM app_from WHERE app_id=? AND from_addr=?", (app_id, from_addr))
con.commit()
def cmd_apps_list(con):
rows = con.execute(
"SELECT app_id, enabled, created_at FROM apps ORDER BY app_id"
).fetchall()
for app_id,en,ts in rows:
print(f"{app_id}\t{'enabled' if en else 'disabled'}\t{ts}")
from_rows = con.execute(
"SELECT from_addr, enabled FROM app_from WHERE app_id=? ORDER BY from_addr",
(app_id,),
).fetchall()
if from_rows:
parts = [f"{addr}" if en else f"{addr} (disabled)" for addr, en in from_rows]
print("\t\t" + ", ".join(parts))
else:
print("\t\t-")
def cmd_init(db_path: str):
con = connect(db_path, create=True)
con.close()
def main():
ap = argparse.ArgumentParser()
ap.add_argument("--db", default=DEFAULT_DB)
sub = ap.add_subparsers(dest="group", required=True)
p_init = sub.add_parser("init")
aliases = sub.add_parser("aliases")
aliases_sub = aliases.add_subparsers(dest="cmd", required=True)
p_add = aliases_sub.add_parser("add")
p_add.add_argument("alias_email")
p_add.add_argument("username")
p_del = aliases_sub.add_parser("del")
p_del.add_argument("alias_email")
p_dis = aliases_sub.add_parser("disable")
p_dis.add_argument("alias_email")
p_ls = aliases_sub.add_parser("list")
p_ls.add_argument("--user", default=None)
apps = sub.add_parser("apps")
apps_sub = apps.add_subparsers(dest="cmd", required=True)
p_app_add = apps_sub.add_parser("add")
p_app_add.add_argument("app_id")
p_app_add.add_argument("password")
p_app_del = apps_sub.add_parser("del")
p_app_del.add_argument("app_id")
p_app_allow = apps_sub.add_parser("allow")
p_app_allow.add_argument("app_id")
p_app_allow.add_argument("from_addr")
p_app_disallow = apps_sub.add_parser("disallow")
p_app_disallow.add_argument("app_id")
p_app_disallow.add_argument("from_addr")
p_app_ls = apps_sub.add_parser("list")
args = ap.parse_args()
if args.group == "init":
cmd_init(args.db)
return
con = connect(args.db)
try:
if args.group == "aliases":
if args.cmd == "add":
cmd_aliases_add(con, args.alias_email, args.username)
elif args.cmd == "del":
cmd_aliases_del(con, args.alias_email)
elif args.cmd == "disable":
cmd_aliases_disable(con, args.alias_email)
elif args.cmd == "list":
cmd_aliases_list(con, args.user)
elif args.group == "apps":
if args.cmd == "add":
cmd_apps_add(con, args.app_id, args.password)
elif args.cmd == "del":
cmd_apps_del(con, args.app_id)
elif args.cmd == "allow":
cmd_apps_allow(con, args.app_id, args.from_addr)
elif args.cmd == "disallow":
cmd_apps_disallow(con, args.app_id, args.from_addr)
elif args.cmd == "list":
cmd_apps_list(con)
finally:
con.close()
if __name__ == "__main__":
sys.exit(main())

1
requirements.txt Normal file
View File

@@ -0,0 +1 @@
argon2-cffi>=23.1.0

BIN
state.db Normal file

Binary file not shown.