mix
8ce050ef7f
Initial feature-complete implementation of the v1.0 specification (phases 0-11 of `docs/implementation-plan.md`). Added: - Panel (Go, single static binary) with SQLite persistence, one-time - Domain management with per-domain DKIM (RSA-2048, generated in pure Go) and - Application (sender identity) management: SASL credentials via `sasldb2`, - Full Postfix relay config generated from env at container start: SMTPS 465, - Journal milter (pure Go, `go-milter`) recording every send to `send_log`; … (6 more in CHANGELOG) Full detail: CHANGELOG.md (0.1.0).
102 lines
3.3 KiB
Go
102 lines
3.3 KiB
Go
package web
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import (
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"fmt"
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"strings"
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"unicode"
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)
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// minAdminPasswordLen is the floor for the administrator password. The panel is
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// public (spec 7.6), so this is deliberately not tiny.
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const minAdminPasswordLen = 12
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const (
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minUsernameLen = 3
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maxUsernameLen = 64
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)
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// validateUsername enforces a strict server-side whitelist (spec 7.6.2):
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// letters, digits, dot, dash, underscore. Client validation is never trusted.
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func validateUsername(u string) error {
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if len(u) < minUsernameLen || len(u) > maxUsernameLen {
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return fmt.Errorf("username must be %d-%d characters", minUsernameLen, maxUsernameLen)
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}
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for _, r := range u {
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if r > unicode.MaxASCII || (!isASCIILetterOrDigit(r) && r != '.' && r != '-' && r != '_') {
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return fmt.Errorf("username may contain only letters, digits, '.', '-' and '_'")
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}
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}
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return nil
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}
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// validateAdminPassword enforces a minimum length. Composition rules beyond
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// length tend to reduce entropy in practice, so length is the sole gate.
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func validateAdminPassword(p string) error {
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if len(p) < minAdminPasswordLen {
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return fmt.Errorf("password must be at least %d characters", minAdminPasswordLen)
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}
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return nil
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}
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func isASCIILetterOrDigit(r rune) bool {
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return (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9')
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}
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const maxDomainLen = 253 // RFC 1035 limit on a fully-qualified name
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// normalizeDomain lower-cases and trims a domain name. Domain names are
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// case-insensitive, and the generated OpenDKIM tables/keys use the canonical
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// lower-case form, so we normalise before both validation and storage.
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func normalizeDomain(name string) string {
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return strings.ToLower(strings.TrimSpace(name))
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}
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// validateDomain enforces a strict server-side whitelist for sending-domain
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// names (spec 7.6.2). The result is safe to write verbatim into the OpenDKIM
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// KeyTable/SigningTable and to use as a filesystem path segment: only
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// lower-case letters, digits, '.' and '-' are allowed, in valid DNS label
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// shape. Input must already be normalised with normalizeDomain.
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//
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// This is deliberately stricter than "any string DNS might accept" — no
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// leading/trailing dots or hyphens, no empty or over-long labels, and at least
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// two labels so single-word hostnames cannot be registered as sending domains.
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func validateDomain(name string) error {
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if name == "" {
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return fmt.Errorf("domain is required")
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}
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if len(name) > maxDomainLen {
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return fmt.Errorf("domain must be at most %d characters", maxDomainLen)
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}
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labels := strings.Split(name, ".")
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if len(labels) < 2 {
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return fmt.Errorf("domain must include at least one dot (e.g. example.com)")
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}
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for _, label := range labels {
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if err := validateDomainLabel(label); err != nil {
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return err
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}
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}
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return nil
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}
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func validateDomainLabel(label string) error {
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if len(label) == 0 {
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return fmt.Errorf("domain must not contain an empty label")
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}
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if len(label) > 63 {
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return fmt.Errorf("each domain label must be at most 63 characters")
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}
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if label[0] == '-' || label[len(label)-1] == '-' {
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return fmt.Errorf("domain labels must not start or end with '-'")
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}
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for i := 0; i < len(label); i++ {
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c := label[i]
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lower := c >= 'a' && c <= 'z'
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digit := c >= '0' && c <= '9'
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if !lower && !digit && c != '-' {
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return fmt.Errorf("domain may contain only lower-case letters, digits, '.' and '-'")
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}
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}
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return nil
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}
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