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
|
/*
* Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <openssl/crypto.h>
#include <openssl/bio.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/err.h>
#include "testutil.h"
static const char *roots_f;
static const char *untrusted_f;
static const char *bad_f;
static const char *good_f;
static X509 *load_cert_pem(const char *file)
{
X509 *cert = NULL;
BIO *bio = NULL;
if (!TEST_ptr(bio = BIO_new(BIO_s_file())))
return NULL;
if (TEST_int_gt(BIO_read_filename(bio, file), 0))
(void)TEST_ptr(cert = PEM_read_bio_X509(bio, NULL, NULL, NULL));
BIO_free(bio);
return cert;
}
static STACK_OF(X509) *load_certs_from_file(const char *filename)
{
STACK_OF(X509) *certs;
BIO *bio;
X509 *x;
bio = BIO_new_file(filename, "r");
if (bio == NULL) {
return NULL;
}
certs = sk_X509_new_null();
if (certs == NULL) {
BIO_free(bio);
return NULL;
}
ERR_set_mark();
do {
x = PEM_read_bio_X509(bio, NULL, 0, NULL);
if (x != NULL && !sk_X509_push(certs, x)) {
sk_X509_pop_free(certs, X509_free);
BIO_free(bio);
return NULL;
} else if (x == NULL) {
/*
* We probably just ran out of certs, so ignore any errors
* generated
*/
ERR_pop_to_mark();
}
} while (x != NULL);
BIO_free(bio);
return certs;
}
/*-
* Test for CVE-2015-1793 (Alternate Chains Certificate Forgery)
*
* Chain is as follows:
*
* rootCA (self-signed)
* |
* interCA
* |
* subinterCA subinterCA (self-signed)
* | |
* leaf ------------------
* |
* bad
*
* rootCA, interCA, subinterCA, subinterCA (ss) all have CA=TRUE
* leaf and bad have CA=FALSE
*
* subinterCA and subinterCA (ss) have the same subject name and keys
*
* interCA (but not rootCA) and subinterCA (ss) are in the trusted store
* (roots.pem)
* leaf and subinterCA are in the untrusted list (untrusted.pem)
* bad is the certificate being verified (bad.pem)
*
* Versions vulnerable to CVE-2015-1793 will fail to detect that leaf has
* CA=FALSE, and will therefore incorrectly verify bad
*
*/
static int test_alt_chains_cert_forgery(void)
{
int ret = 0;
int i;
X509 *x = NULL;
STACK_OF(X509) *untrusted = NULL;
BIO *bio = NULL;
X509_STORE_CTX *sctx = NULL;
X509_STORE *store = NULL;
X509_LOOKUP *lookup = NULL;
store = X509_STORE_new();
if (store == NULL)
goto err;
lookup = X509_STORE_add_lookup(store, X509_LOOKUP_file());
if (lookup == NULL)
goto err;
if (!X509_LOOKUP_load_file(lookup, roots_f, X509_FILETYPE_PEM))
goto err;
untrusted = load_certs_from_file(untrusted_f);
if ((bio = BIO_new_file(bad_f, "r")) == NULL)
goto err;
if ((x = PEM_read_bio_X509(bio, NULL, 0, NULL)) == NULL)
goto err;
sctx = X509_STORE_CTX_new();
if (sctx == NULL)
goto err;
if (!X509_STORE_CTX_init(sctx, store, x, untrusted))
goto err;
i = X509_verify_cert(sctx);
if (i != 0 || X509_STORE_CTX_get_error(sctx) != X509_V_ERR_INVALID_CA)
goto err;
/* repeat with X509_V_FLAG_X509_STRICT */
X509_STORE_CTX_cleanup(sctx);
X509_STORE_set_flags(store, X509_V_FLAG_X509_STRICT);
if (!X509_STORE_CTX_init(sctx, store, x, untrusted))
goto err;
i = X509_verify_cert(sctx);
if (i == 0 && X509_STORE_CTX_get_error(sctx) == X509_V_ERR_INVALID_CA)
/* This is the result we were expecting: Test passed */
ret = 1;
err:
X509_STORE_CTX_free(sctx);
X509_free(x);
BIO_free(bio);
sk_X509_pop_free(untrusted, X509_free);
X509_STORE_free(store);
return ret;
}
static int test_store_ctx(void)
{
X509_STORE_CTX *sctx = NULL;
X509 *x = NULL;
BIO *bio = NULL;
int testresult = 0, ret;
bio = BIO_new_file(bad_f, "r");
if (bio == NULL)
goto err;
x = PEM_read_bio_X509(bio, NULL, 0, NULL);
if (x == NULL)
goto err;
sctx = X509_STORE_CTX_new();
if (sctx == NULL)
goto err;
if (!X509_STORE_CTX_init(sctx, NULL, x, NULL))
goto err;
/* Verifying a cert where we have no trusted certs should fail */
ret = X509_verify_cert(sctx);
if (ret == 0) {
/* This is the result we were expecting: Test passed */
testresult = 1;
}
err:
X509_STORE_CTX_free(sctx);
X509_free(x);
BIO_free(bio);
return testresult;
}
static int test_self_signed(const char *filename, int expected)
{
X509 *cert = load_cert_pem(filename);
STACK_OF(X509) *trusted = sk_X509_new_null();
X509_STORE_CTX *ctx = X509_STORE_CTX_new();
int ret;
ret = TEST_ptr(cert)
&& TEST_true(sk_X509_push(trusted, cert))
&& TEST_true(X509_STORE_CTX_init(ctx, NULL, cert, NULL));
X509_STORE_CTX_set0_trusted_stack(ctx, trusted);
ret = ret && TEST_int_eq(X509_verify_cert(ctx), expected);
X509_STORE_CTX_free(ctx);
sk_X509_free(trusted);
X509_free(cert);
return ret;
}
static int test_self_signed_good(void)
{
return test_self_signed(good_f, 1);
}
static int test_self_signed_bad(void)
{
return test_self_signed(bad_f, 0);
}
int setup_tests(void)
{
if (!TEST_ptr(roots_f = test_get_argument(0))
|| !TEST_ptr(untrusted_f = test_get_argument(1))
|| !TEST_ptr(bad_f = test_get_argument(2))
|| !TEST_ptr(good_f = test_get_argument(3))) {
TEST_error("usage: verify_extra_test roots.pem untrusted.pem bad.pem good.pem\n");
return 0;
}
ADD_TEST(test_alt_chains_cert_forgery);
ADD_TEST(test_store_ctx);
ADD_TEST(test_self_signed_good);
ADD_TEST(test_self_signed_bad);
return 1;
}
|