Add ListResolvableAliases to the user service (#4609)

* Add ListResolvableAliases to the user service

There are a few non common ways this method uses our ACL
and grant system. A user is able to list resolvable
aliases for another user if they are granted permission
to do so. That means we had to load the grants for
the user being listed for and not the requester when
determining if an alias is able to resolve to a destination
for which the requested user has permission.

Similarly, the grant hash used for the list pagination
is required to be that of the user being listed and not
the requester.

internal/daemon/controller/auth/auth.go

@@ -5,13 +5,9 @@ package auth
 
 import (
 	"context"
-	"encoding/binary"
 	stderrors "errors"
 	"fmt"
-	"hash"
-	"hash/fnv"
 	"net/http"
-	"slices"
 	"strings"
 	"time"
 
@@ -102,7 +98,7 @@ type VerifyResults struct {
 	v *verifier
 
 	// Used to generate a hash of all grants
-	grants []perms.GrantTuple
+	grants perms.GrantTuples
 }
 
 type verifier struct {
@@ -947,49 +943,5 @@ func (r *VerifyResults) ScopesAuthorizedForList(ctx context.Context, rootScopeId
 
 // GrantsHash returns a stable hash of all the grants in the verify results.
 func (r *VerifyResults) GrantsHash(ctx context.Context) ([]byte, error) {
-	const op = "auth.GrantsHash"
-	var values []string
-	for _, grant := range r.grants {
-		values = append(values, grant.Grant, grant.RoleId, grant.ScopeId)
-	}
-	// Sort for deterministic output
-	slices.Sort(values)
-	hashVal, err := hashStrings(values...)
-	if err != nil {
-		return nil, errors.Wrap(ctx, err, op)
-	}
-	return binary.LittleEndian.AppendUint64(make([]byte, 0, 4), hashVal), nil
-}
-
-func hashStrings(s ...string) (uint64, error) {
-	hasher := fnv.New64()
-	var h uint64
-	var err error
-	for _, current := range s {
-		hasher.Reset()
-		if _, err = hasher.Write([]byte(current)); err != nil {
-			return 0, err
-		}
-		if h, err = hashUpdateOrdered(hasher, h, hasher.Sum64()); err != nil {
-			return 0, err
-		}
-	}
-	return h, nil
-}
-
-// hashUpdateOrdered is taken directly from
-// https://github.com/mitchellh/hashstructure
-func hashUpdateOrdered(h hash.Hash64, a, b uint64) (uint64, error) {
-	// For ordered updates, use a real hash function
-	h.Reset()
-
-	e1 := binary.Write(h, binary.LittleEndian, a)
-	e2 := binary.Write(h, binary.LittleEndian, b)
-	if e1 != nil {
-		return 0, e1
-	}
-	if e2 != nil {
-		return 0, e2
-	}
-	return h.Sum64(), nil
+	return r.grants.GrantHash(ctx)
 }