backport of commit 3e72c76 (#19621)

Co-authored-by: Violet Hynes <[email protected]>

vault/request_handling.go

@@ -1818,8 +1818,9 @@ func (c *Core) PopulateTokenEntry(ctx context.Context, req *logical.Request) err
 	token := req.ClientToken
 	var err error
 	req.InboundSSCToken = token
+	decodedToken := token
 	if IsSSCToken(token) {
-		token, err = c.CheckSSCToken(ctx, token, c.isLoginRequest(ctx, req), c.perfStandby)
+		decodedToken, err = c.CheckSSCToken(ctx, token, c.isLoginRequest(ctx, req), c.perfStandby)
 		// If we receive an error from CheckSSCToken, we can assume the token is bad somehow, and the client
 		// should receive a 403 bad token error like they do for all other invalid tokens, unless the error
 		// specifies that we should forward the request or retry the request.
@@ -1830,12 +1831,18 @@ func (c *Core) PopulateTokenEntry(ctx context.Context, req *logical.Request) err
 			return logical.ErrPermissionDenied
 		}
 	}
-	req.ClientToken = token
+	req.ClientToken = decodedToken
+	// We ignore the token returned from CheckSSCToken here as Lookup also decodes the SSCT, and
+	// it may need the original SSCT to check state.
 	te, err := c.LookupToken(ctx, token)
 	if err != nil {
+		// If we're missing required state, return that error as-is to the client
+		if errors.Is(err, logical.ErrPerfStandbyPleaseForward) || errors.Is(err, logical.ErrMissingRequiredState) {
+			return err
+		}
 		// If we have two dots but the second char is a dot it's a vault
 		// token of the form s.SOMETHING.nsid, not a JWT
-		if !IsJWT(token) {
+		if !IsJWT(decodedToken) {
 			return fmt.Errorf("error performing token check: %w", err)
 		}
 	}

vault/token_store.go

@@ -1553,6 +1553,10 @@ func (ts *TokenStore) lookupInternal(ctx context.Context, id string, salted, tai
 		return ts.lookupBatchToken(ctx, id)
 	}
 
+	// Before we check to see if this is an SSCT, keep the old value in case
+	// we need to check the full SSCT flow later.
+	originalToken := id
+
 	// lookupInternal is called internally with tokens that oftentimes come from request
 	// parameters that we cannot really guess. Most notably, these calls come from either
 	// validateWrappedToken and/or lookupTokenTainted, used in the wrapping token logic.
@@ -1696,6 +1700,17 @@ func (ts *TokenStore) lookupInternal(ctx context.Context, id string, salted, tai
 	// It's any kind of expiring token with no lease, immediately delete it
 	case le == nil:
 		if ts.core.perfStandby {
+			// If we're a perf standby with a token but without the lease entry, then
+			// we have the WALs for the token but not the lease entry. We should check
+			// the SSCToken again to validate our state. We will receive a 412 if we
+			// don't have the requisite state.
+			// We set unauth to 'false' here as we want to validate the full SSCT flow
+			// and if we're at this point in the method, we have reason to need the token.
+			_, err = ts.core.CheckSSCToken(ctx, originalToken, false, ts.core.perfStandby)
+			if err != nil {
+				return nil, err
+			}
+			// If we don't have a state error, and we're still here, return a 500.
 			return nil, fmt.Errorf("no lease entry found for token that ought to have one, possible eventual consistency issue")
 		}