Commit 9a4f05b0 authored by Nick Mathewson's avatar Nick Mathewson 🎨
Browse files

Split X509 code out of tortls.c

parent 3ccb94d7
......@@ -70,6 +70,7 @@
#include "core/or/var_cell_st.h"
#include "lib/tls/tortls.h"
#include "lib/tls/x509.h"
/** How many CELL_PADDING cells have we received, ever? */
uint64_t stats_n_padding_cells_processed = 0;
......
......@@ -73,6 +73,7 @@
#include "lib/crypt_ops/crypto_format.h"
#include "lib/tls/tortls.h"
#include "lib/tls/x509.h"
static int connection_tls_finish_handshake(or_connection_t *conn);
static int connection_or_launch_v3_or_handshake(or_connection_t *conn);
......
......@@ -33,6 +33,7 @@
#include "lib/log/log.h"
#include "trunnel/link_handshake.h"
#include "lib/tls/tortls.h"
#include "lib/tls/x509.h"
#include "core/or/or_handshake_certs_st.h"
......
......@@ -24,6 +24,7 @@
#include "lib/crypt_ops/crypto_util.h"
#include "lib/term/getpass.h"
#include "lib/tls/tortls.h"
#include "lib/tls/x509.h"
#include "lib/crypt_ops/crypto_format.h"
#define ENC_KEY_HEADER "Boxed Ed25519 key"
......
......@@ -7,7 +7,8 @@ endif
src_lib_libtor_tls_a_SOURCES = \
src/lib/tls/buffers_tls.c \
src/lib/tls/tortls.c
src/lib/tls/tortls.c \
src/lib/tls/x509.c
src_lib_libtor_tls_a_CFLAGS = $(AM_CFLAGS) $(TOR_CFLAGS_CRYPTLIB)
......@@ -20,4 +21,5 @@ src_lib_libtor_tls_testing_a_CFLAGS = \
noinst_HEADERS += \
src/lib/tls/ciphers.inc \
src/lib/tls/buffers_tls.h \
src/lib/tls/tortls.h
src/lib/tls/tortls.h \
src/lib/tls/x509.h
......@@ -28,6 +28,7 @@
#include "lib/crypt_ops/crypto_rand.h"
#include "lib/crypt_ops/crypto_dh.h"
#include "lib/crypt_ops/crypto_util.h"
#include "lib/tls/x509.h"
/* Some versions of OpenSSL declare SSL_get_selected_srtp_profile twice in
* srtp.h. Suppress the GCC warning so we can build with -Wredundant-decl. */
......@@ -67,26 +68,6 @@ ENABLE_GCC_WARNING(redundant-decls)
#include "lib/arch/bytes.h"
#ifdef OPENSSL_1_1_API
#define X509_get_notBefore_const(cert) \
X509_get0_notBefore(cert)
#define X509_get_notAfter_const(cert) \
X509_get0_notAfter(cert)
#ifndef X509_get_notBefore
#define X509_get_notBefore(cert) \
X509_getm_notBefore(cert)
#endif
#ifndef X509_get_notAfter
#define X509_get_notAfter(cert) \
X509_getm_notAfter(cert)
#endif
#else /* ! OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,1,0) */
#define X509_get_notBefore_const(cert) \
((const ASN1_TIME*) X509_get_notBefore((X509 *)cert))
#define X509_get_notAfter_const(cert) \
((const ASN1_TIME*) X509_get_notAfter((X509 *)cert))
#endif
/* Copied from or.h */
#define LEGAL_NICKNAME_CHARACTERS \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
......@@ -162,10 +143,6 @@ tor_tls_get_by_ssl(const SSL *ssl)
static void tor_tls_context_decref(tor_tls_context_t *ctx);
static void tor_tls_context_incref(tor_tls_context_t *ctx);
static int check_cert_lifetime_internal(int severity, const X509 *cert,
time_t now,
int past_tolerance, int future_tolerance);
/** Global TLS contexts. We keep them here because nobody else needs
* to touch them.
*
......@@ -267,7 +244,7 @@ tor_tls_log_one_error(tor_tls_t *tls, unsigned long err,
/** Log all pending tls errors at level <b>severity</b> in log domain
* <b>domain</b>. Use <b>doing</b> to describe our current activities.
*/
STATIC void
void
tls_log_errors(tor_tls_t *tls, int severity, int domain, const char *doing)
{
unsigned long err;
......@@ -375,7 +352,7 @@ tor_tls_get_error(tor_tls_t *tls, int r, int extra,
/** Initialize OpenSSL, unless it has already been initialized.
*/
static void
void
tor_tls_init(void)
{
check_no_tls_errors();
......@@ -459,145 +436,6 @@ always_accept_verify_cb(int preverify_ok,
return 1;
}
/** Return a newly allocated X509 name with commonName <b>cname</b>. */
static X509_NAME *
tor_x509_name_new(const char *cname)
{
int nid;
X509_NAME *name;
/* LCOV_EXCL_BR_START : these branches will only fail on OOM errors */
if (!(name = X509_NAME_new()))
return NULL;
if ((nid = OBJ_txt2nid("commonName")) == NID_undef) goto error;
if (!(X509_NAME_add_entry_by_NID(name, nid, MBSTRING_ASC,
(unsigned char*)cname, -1, -1, 0)))
goto error;
/* LCOV_EXCL_BR_STOP */
return name;
/* LCOV_EXCL_START : these lines will only execute on out of memory errors*/
error:
X509_NAME_free(name);
return NULL;
/* LCOV_EXCL_STOP */
}
/** Generate and sign an X509 certificate with the public key <b>rsa</b>,
* signed by the private key <b>rsa_sign</b>. The commonName of the
* certificate will be <b>cname</b>; the commonName of the issuer will be
* <b>cname_sign</b>. The cert will be valid for <b>cert_lifetime</b>
* seconds, starting from some time in the past.
*
* Return a certificate on success, NULL on failure.
*/
MOCK_IMPL(STATIC X509 *,
tor_tls_create_certificate,(crypto_pk_t *rsa,
crypto_pk_t *rsa_sign,
const char *cname,
const char *cname_sign,
unsigned int cert_lifetime))
{
/* OpenSSL generates self-signed certificates with random 64-bit serial
* numbers, so let's do that too. */
#define SERIAL_NUMBER_SIZE 8
time_t start_time, end_time;
BIGNUM *serial_number = NULL;
unsigned char serial_tmp[SERIAL_NUMBER_SIZE];
EVP_PKEY *sign_pkey = NULL, *pkey=NULL;
X509 *x509 = NULL;
X509_NAME *name = NULL, *name_issuer=NULL;
tor_tls_init();
/* Make sure we're part-way through the certificate lifetime, rather
* than having it start right now. Don't choose quite uniformly, since
* then we might pick a time where we're about to expire. Lastly, be
* sure to start on a day boundary. */
time_t now = time(NULL);
/* Our certificate lifetime will be cert_lifetime no matter what, but if we
* start cert_lifetime in the past, we'll have 0 real lifetime. instead we
* start up to (cert_lifetime - min_real_lifetime - start_granularity) in
* the past. */
const time_t min_real_lifetime = 24*3600;
const time_t start_granularity = 24*3600;
time_t earliest_start_time;
/* Don't actually start in the future! */
if (cert_lifetime <= min_real_lifetime + start_granularity) {
earliest_start_time = now - 1;
} else {
earliest_start_time = now + min_real_lifetime + start_granularity
- cert_lifetime;
}
start_time = crypto_rand_time_range(earliest_start_time, now);
/* Round the start time back to the start of a day. */
start_time -= start_time % start_granularity;
end_time = start_time + cert_lifetime;
tor_assert(rsa);
tor_assert(cname);
tor_assert(rsa_sign);
tor_assert(cname_sign);
if (!(sign_pkey = crypto_pk_get_openssl_evp_pkey_(rsa_sign,1)))
goto error;
if (!(pkey = crypto_pk_get_openssl_evp_pkey_(rsa,0)))
goto error;
if (!(x509 = X509_new()))
goto error;
if (!(X509_set_version(x509, 2)))
goto error;
{ /* our serial number is 8 random bytes. */
crypto_rand((char *)serial_tmp, sizeof(serial_tmp));
if (!(serial_number = BN_bin2bn(serial_tmp, sizeof(serial_tmp), NULL)))
goto error;
if (!(BN_to_ASN1_INTEGER(serial_number, X509_get_serialNumber(x509))))
goto error;
}
if (!(name = tor_x509_name_new(cname)))
goto error;
if (!(X509_set_subject_name(x509, name)))
goto error;
if (!(name_issuer = tor_x509_name_new(cname_sign)))
goto error;
if (!(X509_set_issuer_name(x509, name_issuer)))
goto error;
if (!X509_time_adj(X509_get_notBefore(x509),0,&start_time))
goto error;
if (!X509_time_adj(X509_get_notAfter(x509),0,&end_time))
goto error;
if (!X509_set_pubkey(x509, pkey))
goto error;
if (!X509_sign(x509, sign_pkey, EVP_sha256()))
goto error;
goto done;
error:
if (x509) {
X509_free(x509);
x509 = NULL;
}
done:
tls_log_errors(NULL, LOG_WARN, LD_NET, "generating certificate");
if (sign_pkey)
EVP_PKEY_free(sign_pkey);
if (pkey)
EVP_PKEY_free(pkey);
if (serial_number)
BN_clear_free(serial_number);
if (name)
X509_NAME_free(name);
if (name_issuer)
X509_NAME_free(name_issuer);
return x509;
#undef SERIAL_NUMBER_SIZE
}
/** List of ciphers that servers should select from when the client might be
* claiming extra unsupported ciphers in order to avoid fingerprinting. */
static const char SERVER_CIPHER_LIST[] =
......@@ -697,156 +535,6 @@ static const char CLIENT_CIPHER_LIST[] =
#undef CIPHER
#undef XCIPHER
/** Free all storage held in <b>cert</b> */
void
tor_x509_cert_free_(tor_x509_cert_t *cert)
{
if (! cert)
return;
if (cert->cert)
X509_free(cert->cert);
tor_free(cert->encoded);
memwipe(cert, 0x03, sizeof(*cert));
/* LCOV_EXCL_BR_START since cert will never be NULL here */
tor_free(cert);
/* LCOV_EXCL_BR_STOP */
}
/**
* Allocate a new tor_x509_cert_t to hold the certificate "x509_cert".
*
* Steals a reference to x509_cert.
*/
MOCK_IMPL(STATIC tor_x509_cert_t *,
tor_x509_cert_new,(X509 *x509_cert))
{
tor_x509_cert_t *cert;
EVP_PKEY *pkey;
RSA *rsa;
int length;
unsigned char *buf = NULL;
if (!x509_cert)
return NULL;
length = i2d_X509(x509_cert, &buf);
cert = tor_malloc_zero(sizeof(tor_x509_cert_t));
if (length <= 0 || buf == NULL) {
goto err;
}
cert->encoded_len = (size_t) length;
cert->encoded = tor_malloc(length);
memcpy(cert->encoded, buf, length);
OPENSSL_free(buf);
cert->cert = x509_cert;
crypto_common_digests(&cert->cert_digests,
(char*)cert->encoded, cert->encoded_len);
if ((pkey = X509_get_pubkey(x509_cert)) &&
(rsa = EVP_PKEY_get1_RSA(pkey))) {
crypto_pk_t *pk = crypto_new_pk_from_openssl_rsa_(rsa);
if (crypto_pk_get_common_digests(pk, &cert->pkey_digests) < 0) {
crypto_pk_free(pk);
EVP_PKEY_free(pkey);
goto err;
}
cert->pkey_digests_set = 1;
crypto_pk_free(pk);
EVP_PKEY_free(pkey);
}
return cert;
err:
/* LCOV_EXCL_START for the same reason as the exclusion above */
tor_free(cert);
log_err(LD_CRYPTO, "Couldn't wrap encoded X509 certificate.");
X509_free(x509_cert);
return NULL;
/* LCOV_EXCL_STOP */
}
/** Return a new copy of <b>cert</b>. */
tor_x509_cert_t *
tor_x509_cert_dup(const tor_x509_cert_t *cert)
{
tor_assert(cert);
X509 *x509 = cert->cert;
return tor_x509_cert_new(X509_dup(x509));
}
/** Read a DER-encoded X509 cert, of length exactly <b>certificate_len</b>,
* from a <b>certificate</b>. Return a newly allocated tor_x509_cert_t on
* success and NULL on failure. */
tor_x509_cert_t *
tor_x509_cert_decode(const uint8_t *certificate, size_t certificate_len)
{
X509 *x509;
const unsigned char *cp = (const unsigned char *)certificate;
tor_x509_cert_t *newcert;
tor_assert(certificate);
check_no_tls_errors();
if (certificate_len > INT_MAX)
goto err;
x509 = d2i_X509(NULL, &cp, (int)certificate_len);
if (!x509)
goto err; /* Couldn't decode */
if (cp - certificate != (int)certificate_len) {
X509_free(x509);
goto err; /* Didn't use all the bytes */
}
newcert = tor_x509_cert_new(x509);
if (!newcert) {
goto err;
}
if (newcert->encoded_len != certificate_len ||
fast_memneq(newcert->encoded, certificate, certificate_len)) {
/* Cert wasn't in DER */
tor_x509_cert_free(newcert);
goto err;
}
return newcert;
err:
tls_log_errors(NULL, LOG_INFO, LD_CRYPTO, "decoding a certificate");
return NULL;
}
/** Set *<b>encoded_out</b> and *<b>size_out</b> to <b>cert</b>'s encoded DER
* representation and length, respectively. */
void
tor_x509_cert_get_der(const tor_x509_cert_t *cert,
const uint8_t **encoded_out, size_t *size_out)
{
tor_assert(cert);
tor_assert(encoded_out);
tor_assert(size_out);
*encoded_out = cert->encoded;
*size_out = cert->encoded_len;
}
/** Return a set of digests for the public key in <b>cert</b>, or NULL if this
* cert's public key is not one we know how to take the digest of. */
const common_digests_t *
tor_x509_cert_get_id_digests(const tor_x509_cert_t *cert)
{
if (cert->pkey_digests_set)
return &cert->pkey_digests;
else
return NULL;
}
/** Return a set of digests for the public key in <b>cert</b>. */
const common_digests_t *
tor_x509_cert_get_cert_digests(const tor_x509_cert_t *cert)
{
return &cert->cert_digests;
}
/** Remove a reference to <b>ctx</b>, and free it if it has no more
* references. */
static void
......@@ -898,28 +586,6 @@ tor_tls_get_my_client_auth_key(void)
return client_tls_context->auth_key;
}
/**
* Return a newly allocated copy of the public key that a certificate
* certifies. Watch out! This returns NULL if the cert's key is not RSA.
*/
crypto_pk_t *
tor_tls_cert_get_key(tor_x509_cert_t *cert)
{
crypto_pk_t *result = NULL;
EVP_PKEY *pkey = X509_get_pubkey(cert->cert);
RSA *rsa;
if (!pkey)
return NULL;
rsa = EVP_PKEY_get1_RSA(pkey);
if (!rsa) {
EVP_PKEY_free(pkey);
return NULL;
}
result = crypto_new_pk_from_openssl_rsa_(rsa);
EVP_PKEY_free(pkey);
return result;
}
/** Return true iff the other side of <b>tls</b> has authenticated to us, and
* the key certified in <b>cert</b> is the same as the key they used to do it.
*/
......@@ -946,71 +612,6 @@ tor_tls_cert_matches_key,(const tor_tls_t *tls, const tor_x509_cert_t *cert))
return result;
}
/** Check whether <b>cert</b> is well-formed, currently live, and correctly
* signed by the public key in <b>signing_cert</b>. If <b>check_rsa_1024</b>,
* make sure that it has an RSA key with 1024 bits; otherwise, just check that
* the key is long enough. Return 1 if the cert is good, and 0 if it's bad or
* we couldn't check it. */
int
tor_tls_cert_is_valid(int severity,
const tor_x509_cert_t *cert,
const tor_x509_cert_t *signing_cert,
time_t now,
int check_rsa_1024)
{
check_no_tls_errors();
EVP_PKEY *cert_key;
int r, key_ok = 0;
if (!signing_cert || !cert)
goto bad;
EVP_PKEY *signing_key = X509_get_pubkey(signing_cert->cert);
if (!signing_key)
goto bad;
r = X509_verify(cert->cert, signing_key);
EVP_PKEY_free(signing_key);
if (r <= 0)
goto bad;
/* okay, the signature checked out right. Now let's check the check the
* lifetime. */
if (check_cert_lifetime_internal(severity, cert->cert, now,
48*60*60, 30*24*60*60) < 0)
goto bad;
cert_key = X509_get_pubkey(cert->cert);
if (check_rsa_1024 && cert_key) {
RSA *rsa = EVP_PKEY_get1_RSA(cert_key);
#ifdef OPENSSL_1_1_API
if (rsa && RSA_bits(rsa) == 1024)
#else
if (rsa && BN_num_bits(rsa->n) == 1024)
#endif
key_ok = 1;
if (rsa)
RSA_free(rsa);
} else if (cert_key) {
int min_bits = 1024;
#ifdef EVP_PKEY_EC
if (EVP_PKEY_base_id(cert_key) == EVP_PKEY_EC)
min_bits = 128;
#endif
if (EVP_PKEY_bits(cert_key) >= min_bits)
key_ok = 1;
}
EVP_PKEY_free(cert_key);
if (!key_ok)
goto bad;
/* XXXX compare DNs or anything? */
return 1;
bad:
tls_log_errors(NULL, LOG_INFO, LD_CRYPTO, "checking a certificate");
return 0;
}
/** Increase the reference count of <b>ctx</b>. */
static void
tor_tls_context_incref(tor_tls_context_t *ctx)
......@@ -2146,63 +1747,6 @@ tor_tls_get_own_cert,(tor_tls_t *tls))
return tor_x509_cert_new(duplicate);
}
/** Warn that a certificate lifetime extends through a certain range. */
static void
log_cert_lifetime(int severity, const X509 *cert, const char *problem,
time_t now)
{
BIO *bio = NULL;
BUF_MEM *buf;
char *s1=NULL, *s2=NULL;
char mytime[33];
struct tm tm;
size_t n;
if (problem)
tor_log(severity, LD_GENERAL,
"Certificate %s. Either their clock is set wrong, or your clock "
"is wrong.",
problem);
if (!(bio = BIO_new(BIO_s_mem()))) {
log_warn(LD_GENERAL, "Couldn't allocate BIO!"); goto end;
}
if (!(ASN1_TIME_print(bio, X509_get_notBefore_const(cert)))) {
tls_log_errors(NULL, LOG_WARN, LD_NET, "printing certificate lifetime");
goto end;
}
BIO_get_mem_ptr(bio, &buf);
s1 = tor_strndup(buf->data, buf->length);
(void)BIO_reset(bio);
if (!(ASN1_TIME_print(bio, X509_get_notAfter_const(cert)))) {
tls_log_errors(NULL, LOG_WARN, LD_NET, "printing certificate lifetime");
goto end;
}
BIO_get_mem_ptr(bio, &buf);
s2 = tor_strndup(buf->data, buf->length);
n = strftime(mytime, 32, "%b %d %H:%M:%S %Y UTC", tor_gmtime_r(&now, &tm));
if (n > 0) {
tor_log(severity, LD_GENERAL,
"(certificate lifetime runs from %s through %s. Your time is %s.)",
s1,s2,mytime);
} else {
tor_log(severity, LD_GENERAL,
"(certificate lifetime runs from %s through %s. "
"Couldn't get your time.)",
s1, s2);
}
end:
/* Not expected to get invoked */
tls_log_errors(NULL, LOG_WARN, LD_NET, "getting certificate lifetime");
if (bio)
BIO_free(bio);
tor_free(s1);
tor_free(s2);
}
/** Helper function: try to extract a link certificate and an identity
* certificate from <b>tls</b>, and store them in *<b>cert_out</b> and
* *<b>id_cert_out</b> respectively. Log all messages at level
......@@ -2325,50 +1869,6 @@ tor_tls_check_lifetime(int severity, tor_tls_t *tls,
return r;
}
/** Helper: check whether <b>cert</b> is expired give or take
* <b>past_tolerance</b> seconds, or not-yet-valid give or take
* <b>future_tolerance</b> seconds. (Relative to the current time
* <b>now</b>.) If it is live, return 0. If it is not live, log a message
* and return -1. */
static int
check_cert_lifetime_internal(int severity, const X509 *cert,
time_t now,
int past_tolerance, int future_tolerance)
{
time_t t;
t = now + future_tolerance;
if (X509_cmp_time(X509_get_notBefore_const(cert), &t) > 0) {
log_cert_lifetime(severity, cert, "not yet valid", now);
return -1;
}
t = now - past_tolerance;
if (X509_cmp_time(X509_get_notAfter_const(cert), &t) < 0) {
log_cert_lifetime(severity, cert, "already expired", now);
return -1;
}
return 0;
}
#ifdef TOR_UNIT_TESTS
/* Testing only: return a new x509 cert with the same contents as <b>inp</b>,
but with the expiration time <b>new_expiration_time</b>, signed with
<b>signing_key</b>. */
STATIC tor_x509_cert_t *
tor_x509_cert_replace_expiration(const tor_x509_cert_t *inp,
time_t new_expiration_time,
crypto_pk_t *signing_key)
{
X509 *newc = X509_dup(inp->cert);
X509_time_adj(X509_get_notAfter(newc), 0, &new_expiration_time);
EVP_PKEY *pk = crypto_pk_get_openssl_evp_pkey_(signing_key, 1);
tor_assert(X509_sign(newc, pk, EVP_sha256()));
EVP_PKEY_free(pk);
return tor_x509_cert_new(newc);
}
#endif /* defined(TOR_UNIT_TESTS) */
/** Return the number of bytes available for reading from <b>tls</b>.
*/
int
......