These functions must really never fail; so have crypto_rand() assert
that it's working okay, and have crypto_seed_rng() demand that
callers check its return value. Also have crypto_seed_rng() check
RAND_status() before returning.
The base64 and base32 functions used to be in crypto.c;
crypto_format.h had no header; some general-purpose functions were in
crypto_curve25519.c.
This patch makes a {crypto,util}_format.[ch], and puts more functions
there. Small modules are beautiful!
Routers now use TAP and ntor onion keys to sign their identity keys,
and put these signatures in their descriptors. That allows other
parties to be confident that the onion keys are indeed controlled by
the router that generated the descriptor.
These commands allow for the creation and management of ephemeral
Onion ("Hidden") services that are either bound to the lifetime of
the originating control connection, or optionally the lifetime of
the tor instance.
Implements #6411.
Incidently, this fixes a bug where the maximum value was never used when
only using crypto_rand_int(). For instance this example below in
rendservice.c never gets to INTRO_POINT_LIFETIME_MAX_SECONDS.
int intro_point_lifetime_seconds =
INTRO_POINT_LIFETIME_MIN_SECONDS +
crypto_rand_int(INTRO_POINT_LIFETIME_MAX_SECONDS -
INTRO_POINT_LIFETIME_MIN_SECONDS);
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
Uses libscrypt when found; otherwise, we don't have scrypt and we
only support openpgp rfc2440 s2k hashing, or pbkdf2.
Includes documentation and unit tests; coverage around 95%. Remaining
uncovered code is sanity-checks that shouldn't be reachable fwict.
Most of these are simple. The only nontrivial part is that our
pattern for using ENUM_BF was confusing doxygen by making declarations
that didn't look like declarations.
It's increasingly apparent that we want to make sure we initialize our
PRNG nice and early, or else OpenSSL will do it for us. (OpenSSL
doesn't do _too_ bad a job, but it's nice to do it ourselves.)
We'll also need this for making sure we initialize the siphash key
before we do any hashes.
Incidentally, this business here where I make crypto_rand mockable:
this is exactly the kind of thing that would make me never want to
include test-support stuff in production builds.
We previously used FILENAME_PRIVATE identifiers mostly for
identifiers exposed only to the unit tests... but also for
identifiers exposed to the benchmarker, and sometimes for
identifiers exposed to a similar module, and occasionally for no
really good reason at all.
Now, we use FILENAME_PRIVATE identifiers for identifiers shared by
Tor and the unit tests. They should be defined static when we
aren't building the unit test, and globally visible otherwise. (The
STATIC macro will keep us honest here.)
For identifiers used only by the unit tests and never by Tor at all,
on the other hand, we wrap them in #ifdef TOR_UNIT_TESTS.
This is not the motivating use case for the split test/non-test
build system; it's just a test example to see how it works, and to
take a chance to clean up the code a little.
Now we can compute the hash and signature of a dirobj before
concatenating the smartlist, and we don't need to play silly games
with sigbuf and realloc any more.
We need a weak RNG in a couple of places where the strong RNG is
both needless and too slow. We had been using the weak RNG from our
platform's libc implementation, but that was problematic (because
many platforms have exceptionally horrible weak RNGs -- like, ones
that only return values between 0 and SHORT_MAX) and because we were
using it in a way that was wrong for LCG-based weak RNGs. (We were
counting on the low bits of the LCG output to be as random as the
high ones, which isn't true.)
This patch adds a separate type for a weak RNG, adds an LCG
implementation for it, and uses that exclusively where we had been
using the platform weak RNG.
Previously, we only used the strong OS entropy source as part of
seeding OpenSSL's RNG. But with curve25519, we'll have occasion to
want to generate some keys using extremely-good entopy, as well as the
means to do so. So let's!
This patch refactors the OS-entropy wrapper into its own
crypto_strongest_rand() function, and makes our new
curve25519_secret_key_generate function try it as appropriate.
This is a customizable extract-and-expand HMAC-KDF for deriving keys.
It derives from RFC5869, which derives its rationale from Krawczyk,
H., "Cryptographic Extraction and Key Derivation: The HKDF Scheme",
Proceedings of CRYPTO 2010, 2010, <http://eprint.iacr.org/2010/264>.
I'm also renaming the existing KDF, now that Tor has two of them.
This is the key derivation scheme specified in ntor.
There are also unit tests.
Apparently some compilers like to eliminate memset() operations on
data that's about to go out-of-scope. I've gone with the safest
possible replacement, which might be a bit slow. I don't think this
is critical path in any way that will affect performance, but if it
is, we can work on that in 0.2.4.
Fixes bug 7352.
In C, we technically aren't supposed to define our own things that
start with an underscore.
This is a purely machine-generated commit. First, I ran this script
on all the headers in src/{common,or,test,tools/*}/*.h :
==============================
use strict;
my %macros = ();
my %skipped = ();
FILE: for my $fn (@ARGV) {
my $f = $fn;
if ($fn !~ /^\.\//) {
$f = "./$fn";
}
$skipped{$fn} = 0;
open(F, $fn);
while (<F>) {
if (/^#ifndef ([A-Za-z0-9_]+)/) {
$macros{$fn} = $1;
next FILE;
}
}
}
print "#!/usr/bin/perl -w -i -p\n\n";
for my $fn (@ARGV) {
if (! exists $macros{$fn}) {
print "# No macro known for $fn!\n" if (!$skipped{$fn});
next;
}
if ($macros{$fn} !~ /_H_?$/) {
print "# Weird macro for $fn...\n";
}
my $goodmacro = uc $fn;
$goodmacro =~ s#.*/##;
$goodmacro =~ s#[\/\-\.]#_#g;
print "s/(?<![A-Za-z0-9_])$macros{$fn}(?![A-Za-z0-9_])/TOR_${goodmacro}/g;\n"
}
==============================
It produced the following output, which I then re-ran on those same files:
==============================
s/(?<![A-Za-z0-9_])_TOR_ADDRESS_H(?![A-Za-z0-9_])/TOR_ADDRESS_H/g;
s/(?<![A-Za-z0-9_])_TOR_AES_H(?![A-Za-z0-9_])/TOR_AES_H/g;
s/(?<![A-Za-z0-9_])_TOR_COMPAT_H(?![A-Za-z0-9_])/TOR_COMPAT_H/g;
s/(?<![A-Za-z0-9_])_TOR_COMPAT_LIBEVENT_H(?![A-Za-z0-9_])/TOR_COMPAT_LIBEVENT_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONTAINER_H(?![A-Za-z0-9_])/TOR_CONTAINER_H/g;
s/(?<![A-Za-z0-9_])_TOR_CRYPTO_H(?![A-Za-z0-9_])/TOR_CRYPTO_H/g;
s/(?<![A-Za-z0-9_])TOR_DI_OPS_H(?![A-Za-z0-9_])/TOR_DI_OPS_H/g;
s/(?<![A-Za-z0-9_])_TOR_MEMAREA_H(?![A-Za-z0-9_])/TOR_MEMAREA_H/g;
s/(?<![A-Za-z0-9_])_TOR_MEMPOOL_H(?![A-Za-z0-9_])/TOR_MEMPOOL_H/g;
s/(?<![A-Za-z0-9_])TOR_PROCMON_H(?![A-Za-z0-9_])/TOR_PROCMON_H/g;
s/(?<![A-Za-z0-9_])_TOR_TORGZIP_H(?![A-Za-z0-9_])/TOR_TORGZIP_H/g;
s/(?<![A-Za-z0-9_])_TOR_TORINT_H(?![A-Za-z0-9_])/TOR_TORINT_H/g;
s/(?<![A-Za-z0-9_])_TOR_LOG_H(?![A-Za-z0-9_])/TOR_TORLOG_H/g;
s/(?<![A-Za-z0-9_])_TOR_TORTLS_H(?![A-Za-z0-9_])/TOR_TORTLS_H/g;
s/(?<![A-Za-z0-9_])_TOR_UTIL_H(?![A-Za-z0-9_])/TOR_UTIL_H/g;
s/(?<![A-Za-z0-9_])_TOR_BUFFERS_H(?![A-Za-z0-9_])/TOR_BUFFERS_H/g;
s/(?<![A-Za-z0-9_])_TOR_CHANNEL_H(?![A-Za-z0-9_])/TOR_CHANNEL_H/g;
s/(?<![A-Za-z0-9_])_TOR_CHANNEL_TLS_H(?![A-Za-z0-9_])/TOR_CHANNELTLS_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITBUILD_H(?![A-Za-z0-9_])/TOR_CIRCUITBUILD_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITLIST_H(?![A-Za-z0-9_])/TOR_CIRCUITLIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITMUX_EWMA_H(?![A-Za-z0-9_])/TOR_CIRCUITMUX_EWMA_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITMUX_H(?![A-Za-z0-9_])/TOR_CIRCUITMUX_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITUSE_H(?![A-Za-z0-9_])/TOR_CIRCUITUSE_H/g;
s/(?<![A-Za-z0-9_])_TOR_COMMAND_H(?![A-Za-z0-9_])/TOR_COMMAND_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONFIG_H(?![A-Za-z0-9_])/TOR_CONFIG_H/g;
s/(?<![A-Za-z0-9_])TOR_CONFPARSE_H(?![A-Za-z0-9_])/TOR_CONFPARSE_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONNECTION_EDGE_H(?![A-Za-z0-9_])/TOR_CONNECTION_EDGE_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONNECTION_H(?![A-Za-z0-9_])/TOR_CONNECTION_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONNECTION_OR_H(?![A-Za-z0-9_])/TOR_CONNECTION_OR_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONTROL_H(?![A-Za-z0-9_])/TOR_CONTROL_H/g;
s/(?<![A-Za-z0-9_])_TOR_CPUWORKER_H(?![A-Za-z0-9_])/TOR_CPUWORKER_H/g;
s/(?<![A-Za-z0-9_])_TOR_DIRECTORY_H(?![A-Za-z0-9_])/TOR_DIRECTORY_H/g;
s/(?<![A-Za-z0-9_])_TOR_DIRSERV_H(?![A-Za-z0-9_])/TOR_DIRSERV_H/g;
s/(?<![A-Za-z0-9_])_TOR_DIRVOTE_H(?![A-Za-z0-9_])/TOR_DIRVOTE_H/g;
s/(?<![A-Za-z0-9_])_TOR_DNS_H(?![A-Za-z0-9_])/TOR_DNS_H/g;
s/(?<![A-Za-z0-9_])_TOR_DNSSERV_H(?![A-Za-z0-9_])/TOR_DNSSERV_H/g;
s/(?<![A-Za-z0-9_])TOR_EVENTDNS_TOR_H(?![A-Za-z0-9_])/TOR_EVENTDNS_TOR_H/g;
s/(?<![A-Za-z0-9_])_TOR_GEOIP_H(?![A-Za-z0-9_])/TOR_GEOIP_H/g;
s/(?<![A-Za-z0-9_])_TOR_HIBERNATE_H(?![A-Za-z0-9_])/TOR_HIBERNATE_H/g;
s/(?<![A-Za-z0-9_])_TOR_MAIN_H(?![A-Za-z0-9_])/TOR_MAIN_H/g;
s/(?<![A-Za-z0-9_])_TOR_MICRODESC_H(?![A-Za-z0-9_])/TOR_MICRODESC_H/g;
s/(?<![A-Za-z0-9_])_TOR_NETWORKSTATUS_H(?![A-Za-z0-9_])/TOR_NETWORKSTATUS_H/g;
s/(?<![A-Za-z0-9_])_TOR_NODELIST_H(?![A-Za-z0-9_])/TOR_NODELIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_NTMAIN_H(?![A-Za-z0-9_])/TOR_NTMAIN_H/g;
s/(?<![A-Za-z0-9_])_TOR_ONION_H(?![A-Za-z0-9_])/TOR_ONION_H/g;
s/(?<![A-Za-z0-9_])_TOR_OR_H(?![A-Za-z0-9_])/TOR_OR_H/g;
s/(?<![A-Za-z0-9_])_TOR_POLICIES_H(?![A-Za-z0-9_])/TOR_POLICIES_H/g;
s/(?<![A-Za-z0-9_])_TOR_REASONS_H(?![A-Za-z0-9_])/TOR_REASONS_H/g;
s/(?<![A-Za-z0-9_])_TOR_RELAY_H(?![A-Za-z0-9_])/TOR_RELAY_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDCLIENT_H(?![A-Za-z0-9_])/TOR_RENDCLIENT_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDCOMMON_H(?![A-Za-z0-9_])/TOR_RENDCOMMON_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDMID_H(?![A-Za-z0-9_])/TOR_RENDMID_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDSERVICE_H(?![A-Za-z0-9_])/TOR_RENDSERVICE_H/g;
s/(?<![A-Za-z0-9_])_TOR_REPHIST_H(?![A-Za-z0-9_])/TOR_REPHIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_REPLAYCACHE_H(?![A-Za-z0-9_])/TOR_REPLAYCACHE_H/g;
s/(?<![A-Za-z0-9_])_TOR_ROUTER_H(?![A-Za-z0-9_])/TOR_ROUTER_H/g;
s/(?<![A-Za-z0-9_])_TOR_ROUTERLIST_H(?![A-Za-z0-9_])/TOR_ROUTERLIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_ROUTERPARSE_H(?![A-Za-z0-9_])/TOR_ROUTERPARSE_H/g;
s/(?<![A-Za-z0-9_])TOR_ROUTERSET_H(?![A-Za-z0-9_])/TOR_ROUTERSET_H/g;
s/(?<![A-Za-z0-9_])TOR_STATEFILE_H(?![A-Za-z0-9_])/TOR_STATEFILE_H/g;
s/(?<![A-Za-z0-9_])_TOR_STATUS_H(?![A-Za-z0-9_])/TOR_STATUS_H/g;
s/(?<![A-Za-z0-9_])TOR_TRANSPORTS_H(?![A-Za-z0-9_])/TOR_TRANSPORTS_H/g;
s/(?<![A-Za-z0-9_])_TOR_TEST_H(?![A-Za-z0-9_])/TOR_TEST_H/g;
s/(?<![A-Za-z0-9_])_TOR_FW_HELPER_H(?![A-Za-z0-9_])/TOR_TOR_FW_HELPER_H/g;
s/(?<![A-Za-z0-9_])_TOR_FW_HELPER_NATPMP_H(?![A-Za-z0-9_])/TOR_TOR_FW_HELPER_NATPMP_H/g;
s/(?<![A-Za-z0-9_])_TOR_FW_HELPER_UPNP_H(?![A-Za-z0-9_])/TOR_TOR_FW_HELPER_UPNP_H/g;
==============================
When we added the check for key size, we required that the keys be
128 bytes. But RSA_size (which defers to BN_num_bytes) will return
128 for keys of length 1017..1024. This patch adds a new
crypto_pk_num_bits() that returns the actual number of significant
bits in the modulus, and uses that to enforce key sizes.
Also, credit the original bug3318 in the changes file.
Rename crypto_pk_check_key_public_exponent to crypto_pk_public_exponent_ok:
it's nice to name predicates s.t. you can tell how to interpret true
and false.
Our regular DH parameters that we use for circuit and rendezvous
crypto are unchanged. This is yet another small step on the path of
protocol fingerprinting resistance.
(Backport from 0.2.2's 5ed73e3807)
Our regular DH parameters that we use for circuit and rendezvous
crypto are unchanged. This is yet another small step on the path of
protocol fingerprinting resistance.
Our public key functions assumed that they were always writing into a
large enough buffer. In one case, they weren't.
(Incorporates fixes from sebastian)
In 5e4d53d535 we made it so that
crypto_cipher_set_key cannot fail. The call will now
always succeed, to returning a boolean for success/failure makes
no sense.
See task 1114. The most plausible explanation for someone sending us weak
DH keys is that they experiment with their Tor code or implement a new Tor
client. Usually, we don't care about such events, especially not on warn
level. If we really care about someone not following the Tor protocol, we
can set ProtocolWarnings to 1.
