feat: auth pattern

Signed-off-by: Norman <[email protected]>

examples/gno.land/p/demo/auth/auth.gno

@@ -0,0 +1,16 @@
+package auth
+
+import (
+	"errors"
+	"std"
+)
+
+type Token interface {
+	Source() std.Realm
+}
+
+type AuthenticateFn = func(auth Token) string
+
+var (
+	ErrInvalidToken = errors.New("invalid token")
+)

examples/gno.land/p/demo/auth/gno.mod

@@ -0,0 +1 @@
+module gno.land/p/demo/auth

examples/gno.land/r/demo/authbanker/authbanker.gno

@@ -0,0 +1,62 @@
+package authbanker
+
+import (
+	"std"
+	"strings"
+
+	"gno.land/p/demo/auth"
+	"gno.land/p/demo/ufmt"
+	"gno.land/r/demo/authreg"
+)
+
+// this example is there mostly to demonstrate auth usage, it is quite limited
+// only EOAs can fund accounts
+
+const denom = "ugnot"
+
+var vaults = make(map[string]int64)
+
+func GetCoins(account string) int64 {
+	return vaults[account]
+}
+
+func SendCoins(atok auth.Token, to string, amount int64) {
+	account := authreg.Authenticate(atok)
+
+	if amount < 1 {
+		panic(ufmt.Errorf("sent amount of %q must be >= 0", denom))
+	}
+	if vaultAmount := vaults[account]; amount > vaultAmount {
+		panic(ufmt.Errorf("not enough %q in account, wanted %d, got %d", denom, amount, vaultAmount))
+	}
+
+	vaults[account] -= amount
+
+	if strings.HasPrefix(to, "/") {
+		vaults[to] += amount
+	} else {
+		realmBanker := std.GetBanker(std.BankerTypeRealmSend)
+		from := std.CurrentRealm().Addr()
+		coins := std.Coins{std.NewCoin(denom, amount)}
+		realmBanker.SendCoins(from, std.Address(to), coins)
+	}
+}
+
+func FundVault(to string) {
+	if !strings.HasPrefix(to, "/") {
+		panic("invalid destination")
+	}
+	// XXX: maybe `authreg.Validate(to)`
+	std.AssertOriginCall()
+	sentCoins := std.GetOrigSend()
+	for _, coin := range sentCoins {
+		if coin.Denom != denom {
+			panic(ufmt.Errorf("only %q supported", denom))
+		}
+		vaults[to] += coin.Amount
+	}
+}
+
+func TotalCoin(denom string) int64 {
+	return std.GetBanker(std.BankerTypeRealmSend).TotalCoin(denom)
+}

examples/gno.land/r/demo/authbanker/gno.mod

@@ -0,0 +1 @@
+module gno.land/p/demo/authbanker

examples/gno.land/r/demo/authreg/authreg.gno

@@ -0,0 +1,26 @@
+package authreg
+
+import (
+	"errors"
+	"path"
+	"std"
+
+	"gno.land/p/demo/auth"
+)
+
+var fns = make(map[string]auth.AuthenticateFn)
+
+// XXX: we could add a slug there
+func Register(authenticate auth.AuthenticateFn) {
+	caller := std.PrevRealm().Addr()
+	fns[caller.String()] = authenticate
+}
+
+func Authenticate(autok auth.Token) string {
+	provider := autok.Source().Addr().String()
+	authFn, ok := fns[provider]
+	if !ok {
+		panic(errors.New("unknown auth provider"))
+	}
+	return path.Join("/", provider, authFn(autok))
+}

examples/gno.land/r/demo/authreg/gno.mod

@@ -0,0 +1 @@
+module gno.land/r/demo/authreg

examples/gno.land/r/demo/subacc/gno.mod

@@ -0,0 +1 @@
+module gno.land/r/demo/subacc

examples/gno.land/r/demo/subacc/subacc.gno

@@ -0,0 +1,47 @@
+package subacc
+
+import (
+	"path"
+	"std"
+
+	"gno.land/p/demo/auth"
+	"gno.land/r/demo/authreg"
+)
+
+var source std.Realm
+
+func init() {
+	source = std.CurrentRealm()
+	authreg.Register(authenticate)
+}
+
+func AuthToken(slug string) auth.Token {
+	caller := std.PrevRealm().Addr()
+	return &token{accountKey: accountKey(caller, slug)}
+}
+
+type token struct {
+	accountKey string
+}
+
+func (a *token) Source() std.Realm {
+	return source
+}
+
+var _ auth.Token = (*token)(nil)
+
+func authenticate(autho auth.Token) string {
+	// this check should ensure we created this object
+	cauth, ok := autho.(*token)
+	if !ok {
+		panic(auth.ErrInvalidToken)
+	}
+
+	return cauth.accountKey
+}
+
+var _ auth.AuthenticateFn = authenticate
+
+func accountKey(creator std.Address, slug string) string {
+	return path.Join("/", creator.String(), slug)
+}

examples/gno.land/r/demo/subacc/subacc_test.gno

@@ -0,0 +1,26 @@
+package subacc_test
+
+import (
+	"path"
+	"std"
+	"testing"
+
+	"gno.land/p/demo/testutils"
+	"gno.land/r/demo/authbanker"
+)
+
+var (
+	alice = testutils.TestAddress("alice")
+)
+
+func TestSubacc(t *testing.T) {
+	accountId := path.Join("/", std.DerivePkgAddr("gno.land/r/demo/subacc").String(), alice.String(), "foo")
+
+	std.TestSetRealm(std.NewUserRealm(alice))
+	std.TestSetOrigSend(std.Coins{{"ugnot", 42}}, nil)
+	authbanker.FundVault(accountId)
+
+	println(authbanker.GetCoins(accountId))
+
+	// XXX: ./examples/gno.land/r/demo/subacc: test pkg: panic: unexpected unreal object
+}