13717288701

Committed 07 Mar 2025 09:03AM UTC coverage: 58.235% (-10.4%) from 68.635%

Build # 13717288701

Build Type

Pull #9546

github

Committed by

web-flow

Commit Message

Merge b6ecf4d11 into 76808a81a

Pull Request Pull Request #9546: macaroons: ip range constraint

Run Details

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53.25

/macaroons/constraints.go

package macaroons

import (
        "bytes"
        "context"
        "fmt"
        "net"
        "strings"
        "time"

        "google.golang.org/grpc/peer"
        "gopkg.in/macaroon-bakery.v2/bakery/checkers"
        macaroon "gopkg.in/macaroon.v2"
)

const (
        // CondLndCustom is the first party caveat condition name that is used
        // for all custom caveats in lnd. Every custom caveat entry will be
        // encoded as the string
        // "lnd-custom <custom-caveat-name> <custom-caveat-condition>"
        // in the serialized macaroon. We choose a single space as the delimiter
        // between the because that is also used by the macaroon bakery library.
        CondLndCustom = "lnd-custom"
)

// CustomCaveatAcceptor is an interface that contains a single method for
// checking whether a macaroon with the given custom caveat name should be
// accepted or not.
type CustomCaveatAcceptor interface {
        // CustomCaveatSupported returns nil if a macaroon with the given custom
        // caveat name can be validated by any component in lnd (for example an
        // RPC middleware). If no component is registered to handle the given
        // custom caveat then an error must be returned. This method only checks
        // the availability of a validating component, not the validity of the
        // macaroon itself.
        CustomCaveatSupported(customCaveatName string) error
}

// Constraint type adds a layer of indirection over macaroon caveats.
type Constraint func(*macaroon.Macaroon) error

// Checker type adds a layer of indirection over macaroon checkers. A Checker
// returns the name of the checker and the checker function; these are used to
// register the function with the bakery service's compound checker.
type Checker func() (string, checkers.Func)

// AddConstraints returns new derived macaroon by applying every passed
// constraint and tightening its restrictions.
func AddConstraints(mac *macaroon.Macaroon,
        cs ...Constraint) (*macaroon.Macaroon, error) {

        // The macaroon library's Clone() method has a subtle bug that doesn't
        // correctly clone all caveats. We need to use our own, safe clone
        // function instead.
        newMac, err := SafeCopyMacaroon(mac)
        if err != nil {
                return nil, err
        }

        for _, constraint := range cs {
                if err := constraint(newMac); err != nil {
                        return nil, err
                }
        }
        return newMac, nil
}

// Each *Constraint function is a functional option, which takes a pointer
// to the macaroon and adds another restriction to it. For each *Constraint,
// the corresponding *Checker is provided if not provided by default.

// TimeoutConstraint restricts the lifetime of the macaroon
// to the amount of seconds given.
func TimeoutConstraint(seconds int64) func(*macaroon.Macaroon) error {
        return func(mac *macaroon.Macaroon) error {
                macaroonTimeout := time.Duration(seconds)
                requestTimeout := time.Now().Add(time.Second * macaroonTimeout)
                caveat := checkers.TimeBeforeCaveat(requestTimeout)
                return mac.AddFirstPartyCaveat([]byte(caveat.Condition))
        }
}

// IPLockConstraint locks a macaroon to a specific IP address. If ipAddr is an
// empty string, this constraint does nothing to accommodate  default value's
// desired behavior.
func IPLockConstraint(ipAddr string) func(*macaroon.Macaroon) error {
        return func(mac *macaroon.Macaroon) error {
                if ipAddr != "" {
                        macaroonIPAddr := net.ParseIP(ipAddr)
                        if macaroonIPAddr == nil {
                                return fmt.Errorf("incorrect macaroon IP-" +
                                        "lock address")
                        }
                        caveat := checkers.Condition("ipaddr",
                                macaroonIPAddr.String())

                        return mac.AddFirstPartyCaveat([]byte(caveat))
                }

                return nil
        }
}

// IPRangeLockConstraint locks a macaroon to a specific IP address range. If
// ipRange is an empty string, this constraint does nothing to accommodate
// default value's desired behavior.
func IPRangeLockConstraint(ipRange string) func(*macaroon.Macaroon) error {
        return func(mac *macaroon.Macaroon) error {
                if ipRange != "" {
                        _, net, err := net.ParseCIDR(ipRange)
                        if err != nil {
                                return fmt.Errorf("incorrect macaroon IP " +
                                        "range")
                        }
                        caveat := checkers.Condition("iprange", net.String())

                        return mac.AddFirstPartyCaveat([]byte(caveat))
                }

                return nil
        }
}

// IPLockChecker accepts client IP from the validation context and compares it
// with IP locked in the macaroon. It is of the `Checker` type.
func IPLockChecker() (string, checkers.Func) {
        return "ipaddr", func(ctx context.Context, cond, arg string) error {
                // Get peer info and extract IP address from it for macaroon
                // check.
                pr, ok := peer.FromContext(ctx)
                if !ok {
                        return fmt.Errorf("unable to get peer info from context")
                }
                peerAddr, _, err := net.SplitHostPort(pr.Addr.String())
                if err != nil {
                        return fmt.Errorf("unable to parse peer address")
                }

                if !net.ParseIP(arg).Equal(net.ParseIP(peerAddr)) {
                        msg := "macaroon locked to different IP address"
                        return fmt.Errorf(msg)
                }
                return nil
        }
}

// IPRangeLockChecker accepts client IP range from the validation context and
// compares it with the IP range locked in the macaroon. It is of the `Checker`
// type.
func IPRangeLockChecker() (string, checkers.Func) {
        return "iprange", func(ctx context.Context, cond, arg string) error {
                // Get peer info and extract IP range from it for macaroon
                // check.
                pr, ok := peer.FromContext(ctx)
                if !ok {
                        return fmt.Errorf("unable to get peer info from context")
                }
                peerAddr, _, err := net.SplitHostPort(pr.Addr.String())
                if err != nil {
                        return fmt.Errorf("unable to parse peer address")
                }

                _, ipNet, err := net.ParseCIDR(arg)
                if err != nil {
                        return fmt.Errorf("unable to parse macaroon IP range")
                }

                if !ipNet.Contains(net.ParseIP(peerAddr)) {
                        msg := "macaroon locked to different IP range"
                        return fmt.Errorf(msg)
                }

                return nil
        }
}

// CustomConstraint returns a function that adds a custom caveat condition to
// a macaroon.
func CustomConstraint(name, condition string) func(*macaroon.Macaroon) error {
        return func(mac *macaroon.Macaroon) error {
                // We rely on a name being set for the interception, so don't
                // allow creating a caveat without a name in the first place.
                if name == "" {
                        return fmt.Errorf("name cannot be empty")
                }

                // The inner (custom) condition is optional.
                outerCondition := fmt.Sprintf("%s %s", name, condition)
                if condition == "" {
                        outerCondition = name
                }

                caveat := checkers.Condition(CondLndCustom, outerCondition)
                return mac.AddFirstPartyCaveat([]byte(caveat))
        }
}

// CustomChecker returns a Checker function that is used by the macaroon bakery
// library to check whether a custom caveat is supported by lnd in general or
// not. Support in this context means: An additional gRPC interceptor was set up
// that validates the content (=condition) of the custom caveat. If such an
// interceptor is in place then the acceptor should return a nil error. If no
// interceptor exists for the custom caveat in the macaroon of a request context
// then a non-nil error should be returned and the macaroon is rejected as a
// whole.
func CustomChecker(acceptor CustomCaveatAcceptor) Checker {
        // We return the general name of all lnd custom macaroons and a function
        // that splits the outer condition to extract the name of the custom
        // condition and the condition itself. In the bakery library that's used
        // here, a caveat always has the following form:
        //
        // <condition-name> <condition-value>
        //
        // Because a checker function needs to be bound to the condition name we
        // have to choose a static name for the first part ("lnd-custom", see
        // CondLndCustom. Otherwise we'd need to register a new Checker function
        // for each custom caveat that's registered. To allow for a generic
        // custom caveat handling, we just add another layer and expand the
        // initial <condition-value> into
        //
        // "<custom-condition-name> <custom-condition-value>"
        //
        // The full caveat string entry of a macaroon that uses this generic
        // mechanism would therefore look like this:
        //
        // "lnd-custom <custom-condition-name> <custom-condition-value>"
        checker := func(_ context.Context, _, outerCondition string) error {
                if outerCondition != strings.TrimSpace(outerCondition) {
                        return fmt.Errorf("unexpected white space found in " +
                                "caveat condition")
                }
                if outerCondition == "" {
                        return fmt.Errorf("expected custom caveat, got empty " +
                                "string")
                }

                // The condition part of the original caveat is now name and
                // condition of the custom caveat (we add a layer of conditions
                // to allow one custom checker to work for all custom lnd
                // conditions that implement arbitrary business logic).
                parts := strings.Split(outerCondition, " ")
                customCaveatName := parts[0]

                return acceptor.CustomCaveatSupported(customCaveatName)
        }

        return func() (string, checkers.Func) {
                return CondLndCustom, checker
        }
}

// HasCustomCaveat tests if the given macaroon has a custom caveat with the
// given custom caveat name.
func HasCustomCaveat(mac *macaroon.Macaroon, customCaveatName string) bool {
        if mac == nil {
                return false
        }

        caveatPrefix := []byte(fmt.Sprintf(
                "%s %s", CondLndCustom, customCaveatName,
        ))
        for _, caveat := range mac.Caveats() {
                if bytes.HasPrefix(caveat.Id, caveatPrefix) {
                        return true
                }
        }

        return false
}

// GetCustomCaveatCondition returns the custom caveat condition for the given
// custom caveat name from the given macaroon.
func GetCustomCaveatCondition(mac *macaroon.Macaroon,
        customCaveatName string) string {

        if mac == nil {
                return ""
        }

        caveatPrefix := []byte(fmt.Sprintf(
                "%s %s ", CondLndCustom, customCaveatName,
        ))
        for _, caveat := range mac.Caveats() {
                // The caveat id has a format of
                // "lnd-custom [custom-caveat-name] [custom-caveat-condition]"
                // and we only want the condition part. If we match the prefix
                // part we return the condition that comes after the prefix.
                if bytes.HasPrefix(caveat.Id, caveatPrefix) {
                        caveatSplit := strings.SplitN(
                                string(caveat.Id),
                                string(caveatPrefix),
                                2,
                        )
                        if len(caveatSplit) == 2 {
                                return caveatSplit[1]
                        }
                }
        }

        // We didn't find a condition for the given custom caveat name.
        return ""
}

1	package macaroons
2
3	import (
4	"bytes"
5	"context"
6	"fmt"
7	"net"
8	"strings"
9	"time"
10
11	"google.golang.org/grpc/peer"
12	"gopkg.in/macaroon-bakery.v2/bakery/checkers"
13	macaroon "gopkg.in/macaroon.v2"
14	)
15
16	const (
17	// CondLndCustom is the first party caveat condition name that is used
18	// for all custom caveats in lnd. Every custom caveat entry will be
19	// encoded as the string
20	// "lnd-custom <custom-caveat-name> <custom-caveat-condition>"
21	// in the serialized macaroon. We choose a single space as the delimiter
22	// between the because that is also used by the macaroon bakery library.
23	CondLndCustom = "lnd-custom"
24	)
25
26	// CustomCaveatAcceptor is an interface that contains a single method for
27	// checking whether a macaroon with the given custom caveat name should be
28	// accepted or not.
29	type CustomCaveatAcceptor interface {
30	// CustomCaveatSupported returns nil if a macaroon with the given custom
31	// caveat name can be validated by any component in lnd (for example an
32	// RPC middleware). If no component is registered to handle the given
33	// custom caveat then an error must be returned. This method only checks
34	// the availability of a validating component, not the validity of the
35	// macaroon itself.
36	CustomCaveatSupported(customCaveatName string) error
37	}
38
39	// Constraint type adds a layer of indirection over macaroon caveats.
40	type Constraint func(*macaroon.Macaroon) error
41
42	// Checker type adds a layer of indirection over macaroon checkers. A Checker
43	// returns the name of the checker and the checker function; these are used to
44	// register the function with the bakery service's compound checker.
45	type Checker func() (string, checkers.Func)
46
47	// AddConstraints returns new derived macaroon by applying every passed
48	// constraint and tightening its restrictions.
49	func AddConstraints(mac *macaroon.Macaroon,
UNCOV 50	cs ...Constraint) (*macaroon.Macaroon, error) {	×
UNCOV 51		×
UNCOV 52	// The macaroon library's Clone() method has a subtle bug that doesn't	×
UNCOV 53	// correctly clone all caveats. We need to use our own, safe clone	×
UNCOV 54	// function instead.	×
UNCOV 55	newMac, err := SafeCopyMacaroon(mac)	×
UNCOV 56	if err != nil {	×
UNCOV 57	return nil, err	×
UNCOV 58	}	×
59
UNCOV 60	for _, constraint := range cs {	×
UNCOV 61	if err := constraint(newMac); err != nil {	×
62	return nil, err	×
63	}	×
64	}
UNCOV 65	return newMac, nil	×
66	}
67
68	// Each *Constraint function is a functional option, which takes a pointer
69	// to the macaroon and adds another restriction to it. For each *Constraint,
70	// the corresponding *Checker is provided if not provided by default.
71
72	// TimeoutConstraint restricts the lifetime of the macaroon
73	// to the amount of seconds given.
UNCOV 74	func TimeoutConstraint(seconds int64) func(*macaroon.Macaroon) error {	×
UNCOV 75	return func(mac *macaroon.Macaroon) error {	×
UNCOV 76	macaroonTimeout := time.Duration(seconds)	×
UNCOV 77	requestTimeout := time.Now().Add(time.Second * macaroonTimeout)	×
UNCOV 78	caveat := checkers.TimeBeforeCaveat(requestTimeout)	×
UNCOV 79	return mac.AddFirstPartyCaveat([]byte(caveat.Condition))	×
UNCOV 80	}	×
81	}
82
83	// IPLockConstraint locks a macaroon to a specific IP address. If ipAddr is an
84	// empty string, this constraint does nothing to accommodate default value's
85	// desired behavior.
UNCOV 86	func IPLockConstraint(ipAddr string) func(*macaroon.Macaroon) error {	×
UNCOV 87	return func(mac *macaroon.Macaroon) error {	×
88	if ipAddr != "" {	×
89	macaroonIPAddr := net.ParseIP(ipAddr)	×
90	if macaroonIPAddr == nil {	×
UNCOV 91	return fmt.Errorf("incorrect macaroon IP-" +	×
UNCOV 92	"lock address")	×
UNCOV 93	}	×
UNCOV 94	caveat := checkers.Condition("ipaddr",	×
UNCOV 95	macaroonIPAddr.String())	×
NEW UNCOV 96		×
NEW UNCOV 97	return mac.AddFirstPartyCaveat([]byte(caveat))	×
98	}
99
NEW UNCOV 100	return nil	×
101	}
102	}
103
104	// IPRangeLockConstraint locks a macaroon to a specific IP address range. If
105	// ipRange is an empty string, this constraint does nothing to accommodate
106	// default value's desired behavior.
NEW 107	func IPRangeLockConstraint(ipRange string) func(*macaroon.Macaroon) error {	×
NEW 108	return func(mac *macaroon.Macaroon) error {	×
NEW 109	if ipRange != "" {	×
NEW 110	_, net, err := net.ParseCIDR(ipRange)	×
NEW 111	if err != nil {	×
NEW 112	return fmt.Errorf("incorrect macaroon IP " +	×
NEW 113	"range")	×
NEW 114	}	×
NEW 115	caveat := checkers.Condition("iprange", net.String())	×
NEW 116		×
117	return mac.AddFirstPartyCaveat([]byte(caveat))	×
118	}
119
120	return nil	×
121	}
122	}
123
124	// IPLockChecker accepts client IP from the validation context and compares it
125	// with IP locked in the macaroon. It is of the `Checker` type.
126	func IPLockChecker() (string, checkers.Func) {	3✔
127	return "ipaddr", func(ctx context.Context, cond, arg string) error {	6✔
128	// Get peer info and extract IP address from it for macaroon	3✔
129	// check.	3✔
130	pr, ok := peer.FromContext(ctx)	3✔
131	if !ok {	3✔
UNCOV 132	return fmt.Errorf("unable to get peer info from context")	×
UNCOV 133	}	×
134	peerAddr, _, err := net.SplitHostPort(pr.Addr.String())	3✔
135	if err != nil {	3✔
UNCOV 136	return fmt.Errorf("unable to parse peer address")	×
UNCOV 137	}	×
138
139	if !net.ParseIP(arg).Equal(net.ParseIP(peerAddr)) {	6✔
140	msg := "macaroon locked to different IP address"	3✔
141	return fmt.Errorf(msg)	3✔
142	}	3✔
143	return nil	3✔
144	}
145	}
146
147	// IPRangeLockChecker accepts client IP range from the validation context and
148	// compares it with the IP range locked in the macaroon. It is of the `Checker`
149	// type.
150	func IPRangeLockChecker() (string, checkers.Func) {	3✔
151	return "iprange", func(ctx context.Context, cond, arg string) error {	6✔
152	// Get peer info and extract IP range from it for macaroon	3✔
153	// check.	3✔
154	pr, ok := peer.FromContext(ctx)	3✔
155	if !ok {	3✔
NEW 156	return fmt.Errorf("unable to get peer info from context")	×
NEW 157	}	×
158	peerAddr, _, err := net.SplitHostPort(pr.Addr.String())	3✔
159	if err != nil {	3✔
NEW 160	return fmt.Errorf("unable to parse peer address")	×
NEW 161	}	×
162
163	_, ipNet, err := net.ParseCIDR(arg)	3✔
164	if err != nil {	3✔
NEW 165	return fmt.Errorf("unable to parse macaroon IP range")	×
NEW 166	}	×
167
168	if !ipNet.Contains(net.ParseIP(peerAddr)) {	6✔
169	msg := "macaroon locked to different IP range"	3✔
170	return fmt.Errorf(msg)	3✔
171	}	3✔
172
173	return nil	3✔
174	}
175	}
176
177	// CustomConstraint returns a function that adds a custom caveat condition to
178	// a macaroon.
179	func CustomConstraint(name, condition string) func(*macaroon.Macaroon) error {	×
180	return func(mac *macaroon.Macaroon) error {	×
181	// We rely on a name being set for the interception, so don't	×
182	// allow creating a caveat without a name in the first place.	×
183	if name == "" {	×
184	return fmt.Errorf("name cannot be empty")	×
185	}	×
186
187	// The inner (custom) condition is optional.
UNCOV 188	outerCondition := fmt.Sprintf("%s %s", name, condition)	×
UNCOV 189	if condition == "" {	×
UNCOV 190	outerCondition = name	×
UNCOV 191	}	×
192
UNCOV 193	caveat := checkers.Condition(CondLndCustom, outerCondition)	×
194	return mac.AddFirstPartyCaveat([]byte(caveat))	×
195	}
196	}
197
198	// CustomChecker returns a Checker function that is used by the macaroon bakery
199	// library to check whether a custom caveat is supported by lnd in general or
200	// not. Support in this context means: An additional gRPC interceptor was set up
201	// that validates the content (=condition) of the custom caveat. If such an
202	// interceptor is in place then the acceptor should return a nil error. If no
203	// interceptor exists for the custom caveat in the macaroon of a request context
204	// then a non-nil error should be returned and the macaroon is rejected as a
205	// whole.
206	func CustomChecker(acceptor CustomCaveatAcceptor) Checker {	3✔
207	// We return the general name of all lnd custom macaroons and a function	3✔
208	// that splits the outer condition to extract the name of the custom	3✔
209	// condition and the condition itself. In the bakery library that's used	3✔
210	// here, a caveat always has the following form:	3✔
211	//	3✔
212	// <condition-name> <condition-value>	3✔
213	//	3✔
214	// Because a checker function needs to be bound to the condition name we	3✔
215	// have to choose a static name for the first part ("lnd-custom", see	3✔
216	// CondLndCustom. Otherwise we'd need to register a new Checker function	3✔
217	// for each custom caveat that's registered. To allow for a generic	3✔
218	// custom caveat handling, we just add another layer and expand the	3✔
219	// initial <condition-value> into	3✔
220	//	3✔
221	// "<custom-condition-name> <custom-condition-value>"	3✔
222	//	3✔
223	// The full caveat string entry of a macaroon that uses this generic	3✔
224	// mechanism would therefore look like this:	3✔
225	//	3✔
226	// "lnd-custom <custom-condition-name> <custom-condition-value>"	3✔
227	checker := func(_ context.Context, _, outerCondition string) error {	6✔
228	if outerCondition != strings.TrimSpace(outerCondition) {	3✔
UNCOV 229	return fmt.Errorf("unexpected white space found in " +	×
UNCOV 230	"caveat condition")	×
UNCOV 231	}	×
232	if outerCondition == "" {	3✔
UNCOV 233	return fmt.Errorf("expected custom caveat, got empty " +	×
UNCOV 234	"string")	×
UNCOV 235	}	×
236
237	// The condition part of the original caveat is now name and
238	// condition of the custom caveat (we add a layer of conditions
239	// to allow one custom checker to work for all custom lnd
240	// conditions that implement arbitrary business logic).
241	parts := strings.Split(outerCondition, " ")	3✔
242	customCaveatName := parts[0]	3✔
243		3✔
244	return acceptor.CustomCaveatSupported(customCaveatName)	3✔
245	}
246
247	return func() (string, checkers.Func) {	6✔
248	return CondLndCustom, checker	3✔
249	}	3✔
250	}
251
252	// HasCustomCaveat tests if the given macaroon has a custom caveat with the
253	// given custom caveat name.
254	func HasCustomCaveat(mac *macaroon.Macaroon, customCaveatName string) bool {	3✔
255	if mac == nil {	3✔
UNCOV 256	return false	×
UNCOV 257	}	×
258
259	caveatPrefix := []byte(fmt.Sprintf(	3✔
260	"%s %s", CondLndCustom, customCaveatName,	3✔
261	))	3✔
262	for _, caveat := range mac.Caveats() {	6✔
263	if bytes.HasPrefix(caveat.Id, caveatPrefix) {	6✔
264	return true	3✔
265	}	3✔
266	}
267
268	return false	3✔
269	}
270
271	// GetCustomCaveatCondition returns the custom caveat condition for the given
272	// custom caveat name from the given macaroon.
273	func GetCustomCaveatCondition(mac *macaroon.Macaroon,
274	customCaveatName string) string {	3✔
275		3✔
276	if mac == nil {	3✔
UNCOV 277	return ""	×
UNCOV 278	}	×
279
280	caveatPrefix := []byte(fmt.Sprintf(	3✔
281	"%s %s ", CondLndCustom, customCaveatName,	3✔
282	))	3✔
283	for _, caveat := range mac.Caveats() {	6✔
284	// The caveat id has a format of	3✔
285	// "lnd-custom [custom-caveat-name] [custom-caveat-condition]"	3✔
286	// and we only want the condition part. If we match the prefix	3✔
287	// part we return the condition that comes after the prefix.	3✔
288	if bytes.HasPrefix(caveat.Id, caveatPrefix) {	6✔
289	caveatSplit := strings.SplitN(	3✔
290	string(caveat.Id),	3✔
291	string(caveatPrefix),	3✔
292	2,	3✔
293	)	3✔
294	if len(caveatSplit) == 2 {	6✔
295	return caveatSplit[1]	3✔
296	}	3✔
297	}
298	}
299
300	// We didn't find a condition for the given custom caveat name.
301	return ""	3✔
302	}

lightningnetwork / lnd / 13717288701

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