diff --git a/cmd/mesh-controller/buscertificate.go b/cmd/mesh-controller/buscertificate.go index 983a05e..e369ad2 100644 --- a/cmd/mesh-controller/buscertificate.go +++ b/cmd/mesh-controller/buscertificate.go @@ -1,6 +1,7 @@ package main import ( + "context" "crypto/rand" "crypto/rsa" "crypto/x509" @@ -12,7 +13,10 @@ import ( "net" "os" "path/filepath" + "strings" "time" + + "github.com/novox/mesh-controller/internal/broker" ) // The bus's own certificate, made by the mesh rather than borrowed from an image. @@ -169,3 +173,86 @@ func writeBusCertificate(crt, key string) error { busCertificateNames, template.NotAfter.Format(time.RFC3339), crt, key) return nil } + +// busAccounts writes the mesh's composed user list to a file. +// +// **For genesis, where no declaration can deliver it** (novox/hq 04-ISSUES/146). Everywhere else +// the list reaches the machine running the bus as a resource of the module that holds it — which +// requires that machine to be an enrolled node, and at genesis it is not: the first node cannot +// enrol because the account it would enrol with cannot be composed onto a bus it has no declaration +// for. The installer breaks that circle by placing the file itself, once, and the module takes the +// file over from its first push. +// +// The same composition, not a second one: this asks the store for the same records and renders them +// with the same composer the declaration uses. A genesis that hand-wrote an account would be a +// second statement of who may say what, able to disagree with the first. +// +// **It writes to standard output unless told a file**, and that is the point: the control plane +// composes and says what it composed, and whoever is raising the machine puts it where that +// machine's bus reads it. A control plane that wrote into the bus's own directory would have to +// know where that is and how to make the server re-read it — which is the module's knowledge, and +// the module is what takes this over on the first push. +// +// broker accounts > /var/lib/mesh-bus-conf/accounts.conf +func busAccounts(ctx context.Context, args []string) error { + into := "" + for i := 0; i < len(args); i++ { + switch args[i] { + case "--into": + if i+1 >= len(args) { + return errors.New("--into needs a file") + } + into = args[i+1] + i++ + default: + return fmt.Errorf("broker accounts --into : %q", args[i]) + } + } + + open, err := openStores(ctx) + if err != nil { + return err + } + defer open.Close() + + records, err := open.inventory.BusRecords(ctx) + if err != nil { + return err + } + users, err := broker.Users(records) + if err != nil { + return err + } + kept, err := open.inventory.BusUsers(ctx) + if err != nil { + return err + } + hashes := make(map[string]string, len(kept)) + for name, u := range kept { + hashes[name] = u.PasswordHash + } + filled, missing := broker.WithPasswords(users, hashes) + if len(missing) > 0 { + // To standard error, always: the composed file may be going to standard output, and a + // remark in the middle of it is a configuration the server refuses to parse. + fmt.Fprintf(os.Stderr, "leaving out %d user(s) the mesh has minted no credential for: %s\n", + len(missing), strings.Join(missing, ", ")) + } + if len(filled) == 0 { + return errors.New("not one user has a credential, so this list would refuse every " + + "connection in the mesh") + } + accounts, err := broker.ComposeAccounts(filled) + if err != nil { + return err + } + if into == "" { + fmt.Print(accounts) + return nil + } + if err := os.WriteFile(into, []byte(accounts), 0o600); err != nil { + return err + } + fmt.Printf("wrote %d user(s) to %s\n", len(filled), into) + return nil +} diff --git a/cmd/mesh-controller/main.go b/cmd/mesh-controller/main.go index 6b0f312..2e32e88 100644 --- a/cmd/mesh-controller/main.go +++ b/cmd/mesh-controller/main.go @@ -88,7 +88,7 @@ func run() error { case "identity": return identityCommand(ctx, args[1:]) case "broker": - return brokerCommand(args[1:]) + return brokerCommand(ctx, args[1:]) case "serve": return serve(ctx) case "upgrade": diff --git a/cmd/mesh-controller/nodes.go b/cmd/mesh-controller/nodes.go index 5a8dd13..3eba5c2 100644 --- a/cmd/mesh-controller/nodes.go +++ b/cmd/mesh-controller/nodes.go @@ -363,12 +363,15 @@ func identityCommand(ctx context.Context, args []string) error { return nil } -func brokerCommand(args []string) error { +func brokerCommand(ctx context.Context, args []string) error { if len(args) > 0 && args[0] == "certificate" { return busCertificate(args[1:]) } + if len(args) > 0 && args[0] == "accounts" { + return busAccounts(ctx, args[1:]) + } if len(args) == 0 || args[0] != "show" { - return errors.New("broker show | broker certificate [--check] --into ") + return errors.New("broker show | broker certificate [--check] --into | broker accounts --into ") } known, err := broker.FromEnvironment() if errors.Is(err, broker.ErrNotConfigured) { diff --git a/internal/broker/genesis_template_test.go b/internal/broker/genesis_template_test.go index 1260f85..d5c3c4e 100644 --- a/internal/broker/genesis_template_test.go +++ b/internal/broker/genesis_template_test.go @@ -62,6 +62,22 @@ func TestTheInstallersFirstUserListIsWhatTheControllerWouldCompose(t *testing.T) // theCarriedAccounts is the accounts file the installer's template writes at genesis. func theCarriedAccounts(t *testing.T) string { + t.Helper() + for _, r := range theTemplate(t) { + if r["id"] == "bus-accounts" { + content, _ := r["content"].(string) + if content == "" { + t.Fatal("the template's accounts file is empty, so the bus would refuse every connection") + } + return content + } + } + t.Fatal("the template carries no accounts file, so a mesh raised from it has a bus nobody may use") + return "" +} + +// theTemplate is the installer's bundle, as resources. +func theTemplate(t *testing.T) []map[string]any { t.Helper() path := filepath.Join("..", "..", "..", "mesh-host", "examples", "foundation-first-node-nats.lock") raw, err := os.ReadFile(path) @@ -81,17 +97,7 @@ func theCarriedAccounts(t *testing.T) string { if err := json.Unmarshal([]byte(strings.Join(lines, "\n")), &bundle); err != nil { t.Fatalf("the template is not readable: %v", err) } - for _, r := range bundle.Resources { - if r["id"] == "bus-accounts" { - content, _ := r["content"].(string) - if content == "" { - t.Fatal("the template's accounts file is empty, so the bus would refuse every connection") - } - return content - } - } - t.Fatal("the template carries no accounts file, so a mesh raised from it has a bus nobody may use") - return "" + return bundle.Resources } // subjectsIn reads one allow-list out of a composed accounts file. diff --git a/internal/inventory/busrecords_test.go b/internal/inventory/busrecords_test.go index 7f61cfe..15cf35d 100644 --- a/internal/inventory/busrecords_test.go +++ b/internal/inventory/busrecords_test.go @@ -8,6 +8,7 @@ import ( "github.com/novox/mesh-controller/internal/broker" "github.com/novox/mesh-controller/internal/catalogue" + "golang.org/x/crypto/bcrypt" ) // Reading the bus's user list out of the mesh's records, against a real store. @@ -164,3 +165,63 @@ func granted(all []string, one string) bool { } return false } + +// **A token is an account on the bus, or it is a string nothing accepts** (novox/hq 04-ISSUES/146). +// +// The composed list names an enrolment user for every machine with a live token, and nothing minted +// a credential for it — so the composer left it out as a user with no password, and every enrolment +// since the mesh moved to this bus was refused by the server before the mesh heard of it. Nothing +// caught it because nothing had enrolled since. +// +// The password cannot be minted, because it is the token's own secret: the machine will present +// exactly that string. So this checks the two halves that make the account usable — that a row +// exists under the name the composer asks for, and that the secret handed out is what that row +// accepts. +func TestIssuingATokenRecordsTheAccountItIsThePasswordOf(t *testing.T) { + inv, ctx := aMeshWith(t) + if _, err := inv.AddNode(ctx, "joiner"); err != nil { + t.Fatal(err) + } + issued, err := inv.IssueToken(ctx, "joiner", time.Hour) + if err != nil { + t.Fatal(err) + } + + name := broker.Principal{Kind: broker.KindEnrolment, Node: "joiner"}.Username() + users, err := inv.BusUsers(ctx) + if err != nil { + t.Fatal(err) + } + user, has := users[name] + if !has { + t.Fatalf("no bus account for %q; the composer would leave the enrolment out and the "+ + "machine would be refused before the mesh heard of it: %v", name, users) + } + if user.Kind != BusEnrolment || user.Node != "joiner" { + t.Errorf("the account is %+v, not this node's enrolment", user) + } + if err := bcrypt.CompareHashAndPassword([]byte(user.PasswordHash), []byte(issued.Secret)); err != nil { + t.Error("the account does not accept the secret the token carries, so presenting the " + + "token would be refused by the server") + } + + // And the composition contains it, which is the thing the server reads. + records, err := inv.BusRecords(ctx) + if err != nil { + t.Fatal(err) + } + derived, err := broker.Users(records) + if err != nil { + t.Fatal(err) + } + hashes := map[string]string{} + for n, u := range users { + hashes[n] = u.PasswordHash + } + _, missing := broker.WithPasswords(derived, hashes) + for _, m := range missing { + if m == name { + t.Fatal("the enrolment user is composed without a password, which is a user nobody can be") + } + } +} diff --git a/internal/inventory/bususers.go b/internal/inventory/bususers.go index c8c983b..eb26704 100644 --- a/internal/inventory/bususers.go +++ b/internal/inventory/bususers.go @@ -51,6 +51,40 @@ const ( // reply, into a module's sealed environment — and the mesh keeps only the hash, so a credential is // never recoverable from the store. A caller that loses it must mint again, which is a rotation and // is meant to feel like one. +// RecordBusPassword records a hash for a password the caller already holds. +// +// **For the one credential the mesh does not choose**: an enrolment token's secret is the password +// of the user that presents it (novox/hq ADR 0004, design 25 §6), so the token cannot be given a +// minted password — it already has one, and the machine will connect with exactly that string. +// Everything else goes through Mint, which chooses and returns the plaintext once. +func (i *Inventory) RecordBusPassword(ctx context.Context, u BusUser, password string) error { + if u.Username == "" || u.Kind == "" { + return errors.New("a bus user needs a username and a kind") + } + if password == "" { + return errors.New("a bus user needs a password") + } + hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost) + if err != nil { + return fmt.Errorf("cannot hash a bus password: %w", err) + } + return i.writeBusUser(ctx, u, string(hash)) +} + +// writeBusUser is the row, whoever chose the password. +func (i *Inventory) writeBusUser(ctx context.Context, u BusUser, hash string) error { + if _, err := i.store.Pool().Exec(ctx, + `insert into bus_user (username, kind, node, module, password_hash) + values ($1, $2, $3, $4, $5) + on conflict (username) do update + set kind = excluded.kind, node = excluded.node, module = excluded.module, + password_hash = excluded.password_hash, minted_at = now()`, + u.Username, u.Kind, u.Node, u.Module, hash); err != nil { + return fmt.Errorf("cannot record the bus user %s: %w", u.Username, err) + } + return nil +} + func (i *Inventory) MintBusPassword(ctx context.Context, u BusUser) (string, error) { if u.Username == "" || u.Kind == "" { return "", errors.New("a bus user needs a username and a kind") @@ -69,14 +103,8 @@ func (i *Inventory) MintBusPassword(ctx context.Context, u BusUser) (string, err return "", fmt.Errorf("cannot hash a bus password: %w", err) } - if _, err := i.store.Pool().Exec(ctx, - `insert into bus_user (username, kind, node, module, password_hash) - values ($1, $2, $3, $4, $5) - on conflict (username) do update - set kind = excluded.kind, node = excluded.node, module = excluded.module, - password_hash = excluded.password_hash, minted_at = now()`, - u.Username, u.Kind, u.Node, u.Module, string(hash)); err != nil { - return "", fmt.Errorf("cannot record the bus user %s: %w", u.Username, err) + if err := i.writeBusUser(ctx, u, string(hash)); err != nil { + return "", err } return password, nil } diff --git a/internal/inventory/nodes.go b/internal/inventory/nodes.go index e4dd752..971927b 100644 --- a/internal/inventory/nodes.go +++ b/internal/inventory/nodes.go @@ -14,6 +14,7 @@ import ( "time" "github.com/jackc/pgx/v5" + "github.com/novox/mesh-controller/internal/broker" "github.com/novox/mesh-controller/internal/store" ) @@ -263,6 +264,29 @@ func (i *Inventory) IssueToken(ctx context.Context, nodeName string, validFor ti return Issued{}, err } + // **And the account that secret is the password of** (novox/hq 04-ISSUES/146). The composed + // user list names an enrolment user for every node with a live token, and nothing minted a + // credential for it — so the composer left it out as a user with no password and every + // enrolment was refused by the server before the mesh heard of it. + // + // Recorded rather than minted: the token's secret IS the password, which is what lets a + // machine's first connection be authenticated by the thing it is enrolling with. It cannot be + // chosen here, because it has already been handed to whoever will present it. + // + // Outside the transaction on purpose. The token is what the mesh promised; a credential that + // the next composition rewrites anyway is not worth failing an issue over, and a token with no + // account is recoverable by issuing another, while an account with no token is a user nobody + // can be. + if err := i.RecordBusPassword(ctx, BusUser{ + Username: broker.Principal{Kind: broker.KindEnrolment, Node: node.Name}.Username(), + Kind: BusEnrolment, + Node: node.Name, + }, secret); err != nil { + return Issued{}, fmt.Errorf( + "the token for %s was issued and the bus account it is the password of was not "+ + "recorded, so this token cannot connect: %w", node.Name, err) + } + return Issued{Node: node, Secret: secret, Expires: expires}, nil }