certificates/acme/linker.go
2022-04-28 19:15:18 -07:00

259 lines
7.6 KiB
Go

package acme
import (
"context"
"fmt"
"net"
"net/http"
"net/url"
"strings"
"github.com/go-chi/chi"
"github.com/smallstep/certificates/api/render"
"github.com/smallstep/certificates/authority"
"github.com/smallstep/certificates/authority/provisioner"
)
// LinkType captures the link type.
type LinkType int
const (
// NewNonceLinkType new-nonce
NewNonceLinkType LinkType = iota
// NewAccountLinkType new-account
NewAccountLinkType
// AccountLinkType account
AccountLinkType
// OrderLinkType order
OrderLinkType
// NewOrderLinkType new-order
NewOrderLinkType
// OrdersByAccountLinkType list of orders owned by account
OrdersByAccountLinkType
// FinalizeLinkType finalize order
FinalizeLinkType
// NewAuthzLinkType authz
NewAuthzLinkType
// AuthzLinkType new-authz
AuthzLinkType
// ChallengeLinkType challenge
ChallengeLinkType
// CertificateLinkType certificate
CertificateLinkType
// DirectoryLinkType directory
DirectoryLinkType
// RevokeCertLinkType revoke certificate
RevokeCertLinkType
// KeyChangeLinkType key rollover
KeyChangeLinkType
)
func (l LinkType) String() string {
switch l {
case NewNonceLinkType:
return "new-nonce"
case NewAccountLinkType:
return "new-account"
case AccountLinkType:
return "account"
case NewOrderLinkType:
return "new-order"
case OrderLinkType:
return "order"
case NewAuthzLinkType:
return "new-authz"
case AuthzLinkType:
return "authz"
case ChallengeLinkType:
return "challenge"
case CertificateLinkType:
return "certificate"
case DirectoryLinkType:
return "directory"
case RevokeCertLinkType:
return "revoke-cert"
case KeyChangeLinkType:
return "key-change"
default:
return fmt.Sprintf("unexpected LinkType '%d'", int(l))
}
}
func GetUnescapedPathSuffix(typ LinkType, provisionerName string, inputs ...string) string {
switch typ {
case NewNonceLinkType, NewAccountLinkType, NewOrderLinkType, NewAuthzLinkType, DirectoryLinkType, KeyChangeLinkType, RevokeCertLinkType:
return fmt.Sprintf("/%s/%s", provisionerName, typ)
case AccountLinkType, OrderLinkType, AuthzLinkType, CertificateLinkType:
return fmt.Sprintf("/%s/%s/%s", provisionerName, typ, inputs[0])
case ChallengeLinkType:
return fmt.Sprintf("/%s/%s/%s/%s", provisionerName, typ, inputs[0], inputs[1])
case OrdersByAccountLinkType:
return fmt.Sprintf("/%s/%s/%s/orders", provisionerName, AccountLinkType, inputs[0])
case FinalizeLinkType:
return fmt.Sprintf("/%s/%s/%s/finalize", provisionerName, OrderLinkType, inputs[0])
default:
return ""
}
}
// NewLinker returns a new Directory type.
func NewLinker(dns, prefix string) Linker {
_, _, err := net.SplitHostPort(dns)
if err != nil && strings.Contains(err.Error(), "too many colons in address") {
// this is most probably an IPv6 without brackets, e.g. ::1, 2001:0db8:85a3:0000:0000:8a2e:0370:7334
// in case a port was appended to this wrong format, we try to extract the port, then check if it's
// still a valid IPv6: 2001:0db8:85a3:0000:0000:8a2e:0370:7334:8443 (8443 is the port). If none of
// these cases, then the input dns is not changed.
lastIndex := strings.LastIndex(dns, ":")
hostPart, portPart := dns[:lastIndex], dns[lastIndex+1:]
if ip := net.ParseIP(hostPart); ip != nil {
dns = "[" + hostPart + "]:" + portPart
} else if ip := net.ParseIP(dns); ip != nil {
dns = "[" + dns + "]"
}
}
return &linker{prefix: prefix, dns: dns}
}
// Linker interface for generating links for ACME resources.
type Linker interface {
GetLink(ctx context.Context, typ LinkType, inputs ...string) string
Middleware(http.Handler) http.Handler
LinkOrder(ctx context.Context, o *Order)
LinkAccount(ctx context.Context, o *Account)
LinkChallenge(ctx context.Context, o *Challenge, azID string)
LinkAuthorization(ctx context.Context, o *Authorization)
LinkOrdersByAccountID(ctx context.Context, orders []string)
}
type linkerKey struct{}
// NewLinkerContext adds the given linker to the context.
func NewLinkerContext(ctx context.Context, v Linker) context.Context {
return context.WithValue(ctx, linkerKey{}, v)
}
// LinkerFromContext returns the current linker from the given context.
func LinkerFromContext(ctx context.Context) (v Linker, ok bool) {
v, ok = ctx.Value(linkerKey{}).(Linker)
return
}
// MustLinkerFromContext returns the current linker from the given context. It
// will panic if it's not in the context.
func MustLinkerFromContext(ctx context.Context) Linker {
if v, ok := LinkerFromContext(ctx); !ok {
panic("acme linker is not the context")
} else {
return v
}
}
type baseURLKey struct{}
func newBaseURLContext(ctx context.Context, r *http.Request) context.Context {
var u *url.URL
if r.Host != "" {
u = &url.URL{Scheme: "https", Host: r.Host}
}
return context.WithValue(ctx, baseURLKey{}, u)
}
func baseURLFromContext(ctx context.Context) *url.URL {
if u, ok := ctx.Value(baseURLKey{}).(*url.URL); ok {
return u
}
return nil
}
// linker generates ACME links.
type linker struct {
prefix string
dns string
}
// Middleware gets the provisioner and current url from the request and sets
// them in the context so we can use the linker to create ACME links.
func (l *linker) Middleware(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
// Add base url to the context.
ctx := newBaseURLContext(r.Context(), r)
// Add provisioner to the context.
nameEscaped := chi.URLParam(r, "provisionerID")
name, err := url.PathUnescape(nameEscaped)
if err != nil {
render.Error(w, WrapErrorISE(err, "error url unescaping provisioner name '%s'", nameEscaped))
return
}
p, err := authority.MustFromContext(ctx).LoadProvisionerByName(name)
if err != nil {
render.Error(w, err)
return
}
acmeProv, ok := p.(*provisioner.ACME)
if !ok {
render.Error(w, NewError(ErrorAccountDoesNotExistType, "provisioner must be of type ACME"))
return
}
ctx = NewProvisionerContext(ctx, Provisioner(acmeProv))
next.ServeHTTP(w, r.WithContext(ctx))
})
}
// GetLink is a helper for GetLinkExplicit.
func (l *linker) GetLink(ctx context.Context, typ LinkType, inputs ...string) string {
var u url.URL
if baseURL := baseURLFromContext(ctx); baseURL != nil {
u = *baseURL
}
if u.Scheme == "" {
u.Scheme = "https"
}
if u.Host == "" {
u.Host = l.dns
}
p := MustProvisionerFromContext(ctx)
u.Path = l.prefix + GetUnescapedPathSuffix(typ, p.GetName(), inputs...)
return u.String()
}
// LinkOrder sets the ACME links required by an ACME order.
func (l *linker) LinkOrder(ctx context.Context, o *Order) {
o.AuthorizationURLs = make([]string, len(o.AuthorizationIDs))
for i, azID := range o.AuthorizationIDs {
o.AuthorizationURLs[i] = l.GetLink(ctx, AuthzLinkType, azID)
}
o.FinalizeURL = l.GetLink(ctx, FinalizeLinkType, o.ID)
if o.CertificateID != "" {
o.CertificateURL = l.GetLink(ctx, CertificateLinkType, o.CertificateID)
}
}
// LinkAccount sets the ACME links required by an ACME account.
func (l *linker) LinkAccount(ctx context.Context, acc *Account) {
acc.OrdersURL = l.GetLink(ctx, OrdersByAccountLinkType, acc.ID)
}
// LinkChallenge sets the ACME links required by an ACME challenge.
func (l *linker) LinkChallenge(ctx context.Context, ch *Challenge, azID string) {
ch.URL = l.GetLink(ctx, ChallengeLinkType, azID, ch.ID)
}
// LinkAuthorization sets the ACME links required by an ACME authorization.
func (l *linker) LinkAuthorization(ctx context.Context, az *Authorization) {
for _, ch := range az.Challenges {
l.LinkChallenge(ctx, ch, az.ID)
}
}
// LinkOrdersByAccountID converts each order ID to an ACME link.
func (l *linker) LinkOrdersByAccountID(ctx context.Context, orders []string) {
for i, id := range orders {
orders[i] = l.GetLink(ctx, OrderLinkType, id)
}
}