forked from hashicorp/vault
-
Notifications
You must be signed in to change notification settings - Fork 2
/
path_login.go
356 lines (313 loc) · 10.3 KB
/
path_login.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
package cert
import (
"bytes"
"crypto/tls"
"crypto/x509"
"encoding/base64"
"encoding/pem"
"errors"
"fmt"
"strings"
"github.com/hashicorp/vault/helper/certutil"
"github.com/hashicorp/vault/helper/policyutil"
"github.com/hashicorp/vault/logical"
"github.com/hashicorp/vault/logical/framework"
"github.com/ryanuber/go-glob"
)
// ParsedCert is a certificate that has been configured as trusted
type ParsedCert struct {
Entry *CertEntry
Certificates []*x509.Certificate
}
func pathLogin(b *backend) *framework.Path {
return &framework.Path{
Pattern: "login",
Fields: map[string]*framework.FieldSchema{
"name": &framework.FieldSchema{
Type: framework.TypeString,
Description: "The name of the certificate role to authenticate against.",
},
},
Callbacks: map[logical.Operation]framework.OperationFunc{
logical.UpdateOperation: b.pathLogin,
},
}
}
func (b *backend) pathLogin(
req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
var matched *ParsedCert
if verifyResp, resp, err := b.verifyCredentials(req, data); err != nil {
return nil, err
} else if resp != nil {
return resp, nil
} else {
matched = verifyResp
}
if matched == nil {
return nil, nil
}
ttl := matched.Entry.TTL
if ttl == 0 {
ttl = b.System().DefaultLeaseTTL()
}
clientCerts := req.Connection.ConnState.PeerCertificates
if len(clientCerts) == 0 {
return logical.ErrorResponse("no client certificate found"), nil
}
skid := base64.StdEncoding.EncodeToString(clientCerts[0].SubjectKeyId)
akid := base64.StdEncoding.EncodeToString(clientCerts[0].AuthorityKeyId)
// Generate a response
resp := &logical.Response{
Auth: &logical.Auth{
InternalData: map[string]interface{}{
"subject_key_id": skid,
"authority_key_id": akid,
},
Policies: matched.Entry.Policies,
DisplayName: matched.Entry.DisplayName,
Metadata: map[string]string{
"cert_name": matched.Entry.Name,
"common_name": clientCerts[0].Subject.CommonName,
"subject_key_id": certutil.GetHexFormatted(clientCerts[0].SubjectKeyId, ":"),
"authority_key_id": certutil.GetHexFormatted(clientCerts[0].AuthorityKeyId, ":"),
},
LeaseOptions: logical.LeaseOptions{
Renewable: true,
TTL: ttl,
},
},
}
return resp, nil
}
func (b *backend) pathLoginRenew(
req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
config, err := b.Config(req.Storage)
if err != nil {
return nil, err
}
if !config.DisableBinding {
var matched *ParsedCert
if verifyResp, resp, err := b.verifyCredentials(req, d); err != nil {
return nil, err
} else if resp != nil {
return resp, nil
} else {
matched = verifyResp
}
if matched == nil {
return nil, nil
}
clientCerts := req.Connection.ConnState.PeerCertificates
if len(clientCerts) == 0 {
return nil, fmt.Errorf("no client certificate found")
}
skid := base64.StdEncoding.EncodeToString(clientCerts[0].SubjectKeyId)
akid := base64.StdEncoding.EncodeToString(clientCerts[0].AuthorityKeyId)
// Certificate should not only match a registered certificate policy.
// Also, the identity of the certificate presented should match the identity of the certificate used during login
if req.Auth.InternalData["subject_key_id"] != skid && req.Auth.InternalData["authority_key_id"] != akid {
return nil, fmt.Errorf("client identity during renewal not matching client identity used during login")
}
}
// Get the cert and use its TTL
cert, err := b.Cert(req.Storage, req.Auth.Metadata["cert_name"])
if err != nil {
return nil, err
}
if cert == nil {
// User no longer exists, do not renew
return nil, nil
}
if !policyutil.EquivalentPolicies(cert.Policies, req.Auth.Policies) {
return nil, fmt.Errorf("policies have changed, not renewing")
}
return framework.LeaseExtend(cert.TTL, 0, b.System())(req, d)
}
func (b *backend) verifyCredentials(req *logical.Request, d *framework.FieldData) (*ParsedCert, *logical.Response, error) {
// Get the connection state
if req.Connection == nil || req.Connection.ConnState == nil {
return nil, logical.ErrorResponse("tls connection required"), nil
}
connState := req.Connection.ConnState
if connState.PeerCertificates == nil || len(connState.PeerCertificates) == 0 {
return nil, logical.ErrorResponse("client certificate must be supplied"), nil
}
clientCert := connState.PeerCertificates[0]
// Allow constraining the login request to a single CertEntry
certName := d.Get("name").(string)
// Load the trusted certificates
roots, trusted, trustedNonCAs := b.loadTrustedCerts(req.Storage, certName)
// If trustedNonCAs is not empty it means that client had registered a non-CA cert
// with the backend.
if len(trustedNonCAs) != 0 {
for _, trustedNonCA := range trustedNonCAs {
tCert := trustedNonCA.Certificates[0]
// Check for client cert being explicitly listed in the config (and matching other constraints)
if tCert.SerialNumber.Cmp(clientCert.SerialNumber) == 0 &&
bytes.Equal(tCert.AuthorityKeyId, clientCert.AuthorityKeyId) &&
b.matchesConstraints(clientCert, trustedNonCA.Certificates, trustedNonCA) {
return trustedNonCA, nil, nil
}
}
}
// Get the list of full chains matching the connection
trustedChains, err := validateConnState(roots, connState)
if err != nil {
return nil, nil, err
}
// If no trusted chain was found, client is not authenticated
if len(trustedChains) == 0 {
return nil, logical.ErrorResponse("invalid certificate or no client certificate supplied"), nil
}
// Search for a ParsedCert that intersects with the validated chains and any additional constraints
matches := make([]*ParsedCert, 0)
for _, trust := range trusted { // For each ParsedCert in the config
for _, tCert := range trust.Certificates { // For each certificate in the entry
for _, chain := range trustedChains { // For each root chain that we matched
for _, cCert := range chain { // For each cert in the matched chain
if tCert.Equal(cCert) && // ParsedCert intersects with matched chain
b.matchesConstraints(clientCert, chain, trust) { // validate client cert + matched chain against the config
// Add the match to the list
matches = append(matches, trust)
}
}
}
}
}
// Fail on no matches
if len(matches) == 0 {
return nil, logical.ErrorResponse("no chain matching all constraints could be found for this login certificate"), nil
}
// Return the first matching entry (for backwards compatibility, we continue to just pick one if multiple match)
return matches[0], nil, nil
}
func (b *backend) matchesConstraints(clientCert *x509.Certificate, trustedChain []*x509.Certificate, config *ParsedCert) bool {
// Default behavior (no names) is to allow all names
nameMatched := len(config.Entry.AllowedNames) == 0
// At least one pattern must match at least one name if any patterns are specified
for _, allowedName := range config.Entry.AllowedNames {
if glob.Glob(allowedName, clientCert.Subject.CommonName) {
nameMatched = true
}
for _, name := range clientCert.DNSNames {
if glob.Glob(allowedName, name) {
nameMatched = true
}
}
for _, name := range clientCert.EmailAddresses {
if glob.Glob(allowedName, name) {
nameMatched = true
}
}
}
return !b.checkForChainInCRLs(trustedChain) && nameMatched
}
// loadTrustedCerts is used to load all the trusted certificates from the backend
func (b *backend) loadTrustedCerts(store logical.Storage, certName string) (pool *x509.CertPool, trusted []*ParsedCert, trustedNonCAs []*ParsedCert) {
pool = x509.NewCertPool()
trusted = make([]*ParsedCert, 0)
trustedNonCAs = make([]*ParsedCert, 0)
names, err := store.List("cert/")
if err != nil {
b.Logger().Error("cert: failed to list trusted certs", "error", err)
return
}
for _, name := range names {
// If we are trying to select a single CertEntry and this isn't it
if certName != "" && name != certName {
continue
}
entry, err := b.Cert(store, strings.TrimPrefix(name, "cert/"))
if err != nil {
b.Logger().Error("cert: failed to load trusted cert", "name", name, "error", err)
continue
}
parsed := parsePEM([]byte(entry.Certificate))
if len(parsed) == 0 {
b.Logger().Error("cert: failed to parse certificate", "name", name)
continue
}
if !parsed[0].IsCA {
trustedNonCAs = append(trustedNonCAs, &ParsedCert{
Entry: entry,
Certificates: parsed,
})
} else {
for _, p := range parsed {
pool.AddCert(p)
}
// Create a ParsedCert entry
trusted = append(trusted, &ParsedCert{
Entry: entry,
Certificates: parsed,
})
}
}
return
}
func (b *backend) checkForChainInCRLs(chain []*x509.Certificate) bool {
badChain := false
for _, cert := range chain {
badCRLs := b.findSerialInCRLs(cert.SerialNumber)
if len(badCRLs) != 0 {
badChain = true
break
}
}
return badChain
}
func (b *backend) checkForValidChain(chains [][]*x509.Certificate) bool {
for _, chain := range chains {
if !b.checkForChainInCRLs(chain) {
return true
}
}
return false
}
// parsePEM parses a PEM encoded x509 certificate
func parsePEM(raw []byte) (certs []*x509.Certificate) {
for len(raw) > 0 {
var block *pem.Block
block, raw = pem.Decode(raw)
if block == nil {
break
}
if (block.Type != "CERTIFICATE" && block.Type != "TRUSTED CERTIFICATE") || len(block.Headers) != 0 {
continue
}
cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
continue
}
certs = append(certs, cert)
}
return
}
// validateConnState is used to validate that the TLS client is authorized
// by at trusted certificate. Most of this logic is lifted from the client
// verification logic here: http://golang.org/src/crypto/tls/handshake_server.go
// The trusted chains are returned.
func validateConnState(roots *x509.CertPool, cs *tls.ConnectionState) ([][]*x509.Certificate, error) {
opts := x509.VerifyOptions{
Roots: roots,
Intermediates: x509.NewCertPool(),
KeyUsages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
}
certs := cs.PeerCertificates
if len(certs) == 0 {
return nil, nil
}
if len(certs) > 1 {
for _, cert := range certs[1:] {
opts.Intermediates.AddCert(cert)
}
}
chains, err := certs[0].Verify(opts)
if err != nil {
if _, ok := err.(x509.UnknownAuthorityError); ok {
return nil, nil
}
return nil, errors.New("failed to verify client's certificate: " + err.Error())
}
return chains, nil
}