Tor  0.4.6.0-alpha-dev
x509.c
1 /* Copyright (c) 2003, Roger Dingledine.
2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
3  * Copyright (c) 2007-2020, The Tor Project, Inc. */
4 /* See LICENSE for licensing information */
5 
6 /**
7  * \file x509_openssl.c
8  * \brief Wrapper functions to present a consistent interface to
9  * X.509 functions.
10  **/
11 
12 #define TOR_X509_PRIVATE
13 #include "lib/tls/x509.h"
14 #include "lib/tls/x509_internal.h"
15 #include "lib/log/util_bug.h"
18 
19 /** Choose the start and end times for a certificate */
20 void
21 tor_tls_pick_certificate_lifetime(time_t now,
22  unsigned int cert_lifetime,
23  time_t *start_time_out,
24  time_t *end_time_out)
25 {
26  tor_assert(cert_lifetime < INT_MAX);
27  time_t start_time, end_time;
28  /* Make sure we're part-way through the certificate lifetime, rather
29  * than having it start right now. Don't choose quite uniformly, since
30  * then we might pick a time where we're about to expire. Lastly, be
31  * sure to start on a day boundary. */
32  /* Our certificate lifetime will be cert_lifetime no matter what, but if we
33  * start cert_lifetime in the past, we'll have 0 real lifetime. instead we
34  * start up to (cert_lifetime - min_real_lifetime - start_granularity) in
35  * the past. */
36  const time_t min_real_lifetime = 24*3600;
37  const time_t start_granularity = 24*3600;
38  time_t earliest_start_time;
39  /* Don't actually start in the future! */
40  if ((int)cert_lifetime <= min_real_lifetime + start_granularity) {
41  earliest_start_time = now - 1;
42  } else {
43  earliest_start_time = now + min_real_lifetime + start_granularity
44  - cert_lifetime;
45  }
46  start_time = crypto_rand_time_range(earliest_start_time, now);
47  /* Round the start time back to the start of a day. */
48  start_time -= start_time % start_granularity;
49 
50  end_time = start_time + cert_lifetime;
51 
52  *start_time_out = start_time;
53  *end_time_out = end_time;
54 }
55 
56 /** Return a set of digests for the public key in <b>cert</b>, or NULL if this
57  * cert's public key is not one we know how to take the digest of. */
58 const common_digests_t *
59 tor_x509_cert_get_id_digests(const tor_x509_cert_t *cert)
60 {
61  if (cert->pkey_digests_set)
62  return &cert->pkey_digests;
63  else
64  return NULL;
65 }
66 
67 /** Return a set of digests for the public key in <b>cert</b>. */
68 const common_digests_t *
69 tor_x509_cert_get_cert_digests(const tor_x509_cert_t *cert)
70 {
71  return &cert->cert_digests;
72 }
73 
74 /** Free all storage held in <b>cert</b> */
75 void
76 tor_x509_cert_free_(tor_x509_cert_t *cert)
77 {
78  if (! cert)
79  return;
80  tor_x509_cert_impl_free(cert->cert);
81 #ifdef ENABLE_OPENSSL
82  tor_free(cert->encoded);
83 #endif
84  memwipe(cert, 0x03, sizeof(*cert));
85  /* LCOV_EXCL_BR_START since cert will never be NULL here */
86  tor_free(cert);
87  /* LCOV_EXCL_BR_STOP */
88 }
89 
90 /**
91  * Allocate a new tor_x509_cert_t to hold the certificate "x509_cert".
92  *
93  * Steals a reference to x509_cert.
94  */
95 MOCK_IMPL(tor_x509_cert_t *,
96 tor_x509_cert_new,(tor_x509_cert_impl_t *x509_cert))
97 {
98  tor_x509_cert_t *cert;
99 
100  if (!x509_cert)
101  return NULL;
102 
103  cert = tor_malloc_zero(sizeof(tor_x509_cert_t));
104  cert->cert = x509_cert;
105 
107  goto err;
108 
109  {
110  const uint8_t *encoded=NULL;
111  size_t encoded_len=0;
112  tor_x509_cert_get_der(cert, &encoded, &encoded_len);
113  tor_assert(encoded);
114  crypto_common_digests(&cert->cert_digests, (char *)encoded, encoded_len);
115  }
116 
117  {
118  crypto_pk_t *pk = tor_tls_cert_get_key(cert);
119  if (pk) {
120  if (crypto_pk_get_common_digests(pk, &cert->pkey_digests) < 0) {
121  log_warn(LD_CRYPTO, "unable to compute digests of certificate key");
122  crypto_pk_free(pk);
123  goto err;
124  }
125  }
126  cert->pkey_digests_set = 1;
127  crypto_pk_free(pk);
128  }
129 
130  return cert;
131  err:
132  log_err(LD_CRYPTO, "Couldn't wrap encoded X509 certificate.");
133  tor_x509_cert_free(cert);
134  return NULL;
135 }
136 
137 /** Return a new copy of <b>cert</b>. */
138 tor_x509_cert_t *
139 tor_x509_cert_dup(const tor_x509_cert_t *cert)
140 {
141  tor_assert(cert);
142  tor_assert(cert->cert);
143  return tor_x509_cert_new(tor_x509_cert_impl_dup_(cert->cert));
144 }
tor_free
#define tor_free(p)
Definition: malloc.h:52
memwipe
void memwipe(void *mem, uint8_t byte, size_t sz)
Definition: crypto_util.c:55
MOCK_IMPL
#define MOCK_IMPL(rv, funcname, arglist)
Definition: testsupport.h:133
tor_assert
#define tor_assert(expr)
Definition: util_bug.h:102
crypto_rand_time_range
time_t crypto_rand_time_range(time_t min, time_t max)
Definition: crypto_rand_numeric.c:95
tor_x509_cert_free_
void tor_x509_cert_free_(tor_x509_cert_t *cert)
Definition: x509.c:76
util_bug.h
Macros to manage assertions, fatal and non-fatal.
common_digests_t
Definition: crypto_digest.h:87
crypto_util.h
Common functions for cryptographic routines.
tor_x509_cert_get_cert_digests
const common_digests_t * tor_x509_cert_get_cert_digests(const tor_x509_cert_t *cert)
Definition: x509.c:69
crypto_common_digests
int crypto_common_digests(common_digests_t *ds_out, const char *m, size_t len)
Definition: crypto_digest.c:30
crypto_rand.h
Common functions for using (pseudo-)random number generators.
crypto_pk_get_common_digests
int crypto_pk_get_common_digests(crypto_pk_t *pk, common_digests_t *digests_out)
Definition: crypto_rsa.c:381
LD_CRYPTO
#define LD_CRYPTO
Definition: log.h:64
tor_tls_cert_get_key
crypto_pk_t * tor_tls_cert_get_key(tor_x509_cert_t *cert)
Definition: x509_nss.c:285
crypto_pk_t
Definition: crypto_rsa_nss.c:37
tor_x509_cert_dup
tor_x509_cert_t * tor_x509_cert_dup(const tor_x509_cert_t *cert)
Definition: x509.c:139
tor_x509_cert_get_der
void tor_x509_cert_get_der(const tor_x509_cert_t *cert, const uint8_t **encoded_out, size_t *size_out)
Definition: x509_nss.c:216
tor_x509_cert_set_cached_der_encoding
int tor_x509_cert_set_cached_der_encoding(tor_x509_cert_t *cert)
Definition: x509_openssl.c:190
tor_x509_cert_get_id_digests
const common_digests_t * tor_x509_cert_get_id_digests(const tor_x509_cert_t *cert)
Definition: x509.c:59
x509.h
Headers for tortls.c.