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Add Ed25519 support, wrappers, and tests. 

Taken from earlier ed25519 branch based on floodyberry's
ed25519-donna.  Tweaked so that it applies to ref10 instead.
This commit is contained in:
Nick Mathewson 2013-09-29 13:30:24 -04:00
parent b2acd3580c
commit 87ba033cd5
8 changed files with 483 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
.gitignore vendored
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@ -134,6 +134,10 @@
/src/config/torrc
/src/config/torrc.sample
# /src/ext/
/src/ext/ed25519/ref10/libed25519_ref10.a
/src/ext/ed25519/ref10/libed25519_ref10.lib
# /src/or/
/src/or/Makefile
/src/or/Makefile.in

42
src/common/crypto_curve25519.c
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@ -63,6 +63,34 @@ curve25519_public_key_is_ok(const curve25519_public_key_t *key)
return !safe_mem_is_zero(key->public_key, CURVE25519_PUBKEY_LEN);
}
/**
* Generate CURVE25519_SECKEY_LEN random bytes in <b>out</b>. If
* <b>extra_strong</b> is true, this key is possibly going to get used more
* than once, so use a better-than-usual RNG. Return 0 on success, -1 on
* failure.
*
* This function does not adjust the output of the RNG at all; the will caller
* will need to clear or set the appropriate bits to make curve25519 work.
*/
int
curve25519_rand_seckey_bytes(uint8_t *out, int extra_strong)
{
uint8_t k_tmp[CURVE25519_SECKEY_LEN];
if (crypto_rand((char*)out, CURVE25519_SECKEY_LEN) < 0)
return -1;
if (extra_strong && !crypto_strongest_rand(k_tmp, CURVE25519_SECKEY_LEN)) {
/* If they asked for extra-strong entropy and we have some, use it as an
* HMAC key to improve not-so-good entropy rather than using it directly,
* just in case the extra-strong entropy is less amazing than we hoped. */
crypto_hmac_sha256((char*) out,
(const char *)k_tmp, sizeof(k_tmp),
(const char *)out, CURVE25519_SECKEY_LEN);
}
memwipe(k_tmp, 0, sizeof(k_tmp));
return 0;
}
/** Generate a new keypair and return the secret key. If <b>extra_strong</b>
* is true, this key is possibly going to get used more than once, so
* use a better-than-usual RNG. Return 0 on success, -1 on failure. */
@ -70,19 +98,9 @@ int
curve25519_secret_key_generate(curve25519_secret_key_t *key_out,
int extra_strong)
{
uint8_t k_tmp[CURVE25519_SECKEY_LEN];
if (crypto_rand((char*)key_out->secret_key, CURVE25519_SECKEY_LEN) < 0)
if (curve25519_rand_seckey_bytes(key_out->secret_key, extra_strong) < 0)
return -1;
if (extra_strong && !crypto_strongest_rand(k_tmp, CURVE25519_SECKEY_LEN)) {
/* If they asked for extra-strong entropy and we have some, use it as an
* HMAC key to improve not-so-good entropy rather than using it directly,
* just in case the extra-strong entropy is less amazing than we hoped. */
crypto_hmac_sha256((char *)key_out->secret_key,
(const char *)k_tmp, sizeof(k_tmp),
(const char *)key_out->secret_key, CURVE25519_SECKEY_LEN);
}
memwipe(k_tmp, 0, sizeof(k_tmp));
key_out->secret_key[0] &= 248;
key_out->secret_key[31] &= 127;
key_out->secret_key[31] |= 64;

2
src/common/crypto_curve25519.h
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@ -57,6 +57,8 @@ int curve25519_keypair_read_from_file(curve25519_keypair_t *keypair_out,
char **tag_out,
const char *fname);
int curve25519_rand_seckey_bytes(uint8_t *out, int extra_strong);
#ifdef CRYPTO_CURVE25519_PRIVATE
STATIC int curve25519_impl(uint8_t *output, const uint8_t *secret,
const uint8_t *basepoint);

181
src/common/crypto_ed25519.c Normal file
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@ -0,0 +1,181 @@
/* Copyright (c) 2013, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/* Wrapper code for an ed25519 implementation. */
#include "orconfig.h"
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include "crypto.h"
#include "crypto_curve25519.h"
#include "crypto_ed25519.h"
#include "torlog.h"
#include "util.h"
#include "ed25519/ref10/ed25519_ref10.h"
int
ed25519_secret_key_generate(ed25519_secret_key_t *seckey_out,
int extra_strong)
{
(void) extra_strong;
if (ed25519_ref10_seckey(seckey_out->seckey) < 0)
return -1;
return 0;
}
int
ed25519_public_key_generate(ed25519_public_key_t *pubkey_out,
const ed25519_secret_key_t *seckey)
{
if (ed25519_ref10_pubkey(pubkey_out->pubkey, seckey->seckey) < 0)
return -1;
return 0;
}
/** Generate a new ed25519 keypair in <b>keypair_out</b>. If
* <b>extra_strong</b> is set, try to mix some system entropy into the key
* generation process. Return 0 on success, -1 on failure. */
int
ed25519_keypair_generate(ed25519_keypair_t *keypair_out, int extra_strong)
{
(void) extra_strong;
if (ed25519_ref10_keygen(keypair_out->pubkey.pubkey,
keypair_out->seckey.seckey)<0)
return -1;
return 0;
}
/**
* Set <b>signature_out</b> to a signature of the <b>len</b>-byte message
* <b>msg</b>, using the secret and public key in <b>keypair</b>.
*/
int
ed25519_sign(ed25519_signature_t *signature_out,
const uint8_t *msg, size_t len,
const ed25519_keypair_t *keypair)
{
uint8_t keys[64];
uint8_t *tmp;
uint64_t tmplen;
/* XXXX Make crypto_sign in ref10 friendlier so we don't need this stupid
* copying. */
tor_assert(len < SIZE_T_CEILING - 64);
tmplen = ((uint64_t)len) + 64;
tmp = tor_malloc(tmplen);
memcpy(keys, keypair->seckey.seckey, 32);
memcpy(keys+32, keypair->pubkey.pubkey, 32);
if (ed25519_ref10_sign(tmp, &tmplen, msg, len, keys) < 0) {
tor_free(tmp);
return -1;
}
memcpy(signature_out->sig, tmp, 64);
memwipe(keys, 0, sizeof(keys));
tor_free(tmp);
return 0;
}
/**
* Check whether if <b>signature</b> is a valid signature for the
* <b>len</b>-byte message in <b>msg</b> made with the key <b>pubkey</b>.
*
* Return 0 if the signature is valid; -1 if it isn't.
*/
int
ed25519_checksig(const ed25519_signature_t *signature,
const uint8_t *msg, size_t len,
const ed25519_public_key_t *pubkey)
{
uint8_t *smtmp;
uint8_t *tmp;
uint64_t tmplen;
int r;
tor_assert(len < SIZE_T_CEILING - 64);
tmplen = len + 64;
tmp = tor_malloc(tmplen);
smtmp = tor_malloc(tmplen);
memcpy(smtmp, signature->sig, 64);
memcpy(smtmp+64, msg, len);
r = ed25519_ref10_open(tmp, &tmplen, smtmp, tmplen, pubkey->pubkey);
tor_free(tmp);
tor_free(smtmp);
return r;
}
/** Validate every signature among those in <b>checkable</b>, which contains
* exactly <b>n_checkable</b> elements. If <b>okay_out</b> is non-NULL, set
* the i'th element of <b>okay_out</b> to 1 if the i'th element of
* <b>checkable</b> is valid, and to 0 otherwise. Return 0 if every signature
* was valid. Otherwise return -N, where N is the number of invalid
* signatures.
*/
int
ed25519_checksig_batch(int *okay_out,
const ed25519_checkable_t *checkable,
int n_checkable)
{
int res, i;
res = 0;
for (i = 0; i < n_checkable; ++i) {
const ed25519_checkable_t *ch = &checkable[i];
int r = ed25519_checksig(&ch->signature, ch->msg, ch->len, ch->pubkey);
if (r < 0)
--res;
if (okay_out)
okay_out[i] = (r == 0);
}
#if 0
const uint8_t **ms;
size_t *lens;
const uint8_t **pks;
const uint8_t **sigs;
int *oks;
ms = tor_malloc(sizeof(uint8_t*)*n_checkable);
lens = tor_malloc(sizeof(size_t)*n_checkable);
pks = tor_malloc(sizeof(uint8_t*)*n_checkable);
sigs = tor_malloc(sizeof(uint8_t*)*n_checkable);
oks = okay_out ? okay_out : tor_malloc(sizeof(int)*n_checkable);
for (i = 0; i < n_checkable; ++i) {
ms[i] = checkable[i].msg;
lens[i] = checkable[i].len;
pks[i] = checkable[i].pubkey->pubkey;
sigs[i] = checkable[i].signature.sig;
oks[i] = 0;
}
ed25519_sign_open_batch_donna_fb(ms, lens, pks, sigs, n_checkable, oks);
res = 0;
for (i = 0; i < n_checkable; ++i) {
if (!oks[i])
--res;
}
tor_free(ms);
tor_free(lens);
tor_free(pks);
if (! okay_out)
tor_free(oks);
#endif
return res;
}

72
src/common/crypto_ed25519.h Normal file
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@ -0,0 +1,72 @@
/* Copyright (c) 2012-2013, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#ifndef TOR_CRYPTO_ED25519_H
#define TOR_CRYPTO_ED25519_H
#include "testsupport.h"
#include "torint.h"
#define ED25519_PUBKEY_LEN 32
#define ED25519_SECKEY_LEN 32
#define ED25519_SIG_LEN 64
/** An Ed25519 signature. */
typedef struct {
uint8_t sig[ED25519_SIG_LEN];
} ed25519_signature_t;
/** An Ed25519 public key */
typedef struct {
uint8_t pubkey[ED25519_PUBKEY_LEN];
} ed25519_public_key_t;
/** An Ed25519 secret key */
typedef struct {
uint8_t seckey[ED25519_SECKEY_LEN];
} ed25519_secret_key_t;
/** An Ed25519 keypair. */
typedef struct {
ed25519_public_key_t pubkey;
ed25519_secret_key_t seckey;
} ed25519_keypair_t;
#ifdef CURVE25519_ENABLED
int ed25519_secret_key_generate(ed25519_secret_key_t *seckey_out,
int extra_strong);
int ed25519_public_key_generate(ed25519_public_key_t *pubkey_out,
const ed25519_secret_key_t *seckey);
int ed25519_keypair_generate(ed25519_keypair_t *keypair_out, int extra_strong);
int ed25519_sign(ed25519_signature_t *signature_out,
const uint8_t *msg, size_t len,
const ed25519_keypair_t *key);
int ed25519_checksig(const ed25519_signature_t *signature,
const uint8_t *msg, size_t len,
const ed25519_public_key_t *pubkey);
/**
* A collection of information necessary to check an Ed25519 signature. Used
* for batch verification.
*/
typedef struct {
/** The public key that supposedly generated the signature. */
ed25519_public_key_t *pubkey;
/** The signature to check. */
ed25519_signature_t signature;
/** The message that the signature is supposed to have been applied to. */
const uint8_t *msg;
/** The length of the message. */
size_t len;
} ed25519_checkable_t;
int ed25519_checksig_batch(int *okay_out,
const ed25519_checkable_t *checkable,
int n_checkable);
#endif
/* XXXX write secret keys to disk, load secret keys from disk, read encrypted,
* write encrypted. serialize public. parse public. */
#endif

7
src/common/include.am
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@ -52,8 +52,12 @@ LIBDONNA=
endif
endif
LIBDONNA += $(LIBED25519_REF10)
if CURVE25519_ENABLED
libcrypto_extra_source=src/common/crypto_curve25519.c
libcrypto_extra_source = \
src/common/crypto_curve25519.c \
src/common/crypto_ed25519.c
endif
LIBOR_A_SOURCES = \
@ -110,6 +114,7 @@ COMMONHEADERS = \
src/common/container.h \
src/common/crypto.h \
src/common/crypto_curve25519.h \
src/common/crypto_ed25519.h \
src/common/di_ops.h \
src/common/memarea.h \
src/common/linux_syscalls.inc \

4
src/ext/include.am
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@ -77,5 +77,7 @@ ED25519_REF10_HDRS = \
src/ext/ed25519/ref10/sqrtm1.h
noinst_HEADERS += $(ED25519_REF10_HDRS)
noinst_LIBRARIES += src/ext/ed25519/ref10/libed25519_ref10.a
LIBED25519_REF10=src/ext/ed25519/ref10/libed25519_ref10.a
noinst_LIBRARIES += $(LIBED25519_REF10)

185
src/test/test_crypto.c
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@ -12,6 +12,7 @@
#include "siphash.h"
#ifdef CURVE25519_ENABLED
#include "crypto_curve25519.h"
#include "crypto_ed25519.h"
#endif
extern const char AUTHORITY_SIGNKEY_3[];
@ -1161,6 +1162,188 @@ test_crypto_curve25519_persist(void *arg)
tor_free(tag);
}
static void
test_crypto_ed25519_simple(void *arg)
{
ed25519_keypair_t kp1, kp2;
ed25519_public_key_t pub1, pub2;
ed25519_secret_key_t sec1, sec2;
ed25519_signature_t sig1, sig2;
const uint8_t msg[] =
"GNU will be able to run Unix programs, "
"but will not be identical to Unix.";
const uint8_t msg2[] =
"Microsoft Windows extends the features of the DOS operating system, "
"yet is compatible with most existing applications that run under DOS.";
size_t msg_len = strlen((const char*)msg);
size_t msg2_len = strlen((const char*)msg2);
(void)arg;
tt_int_op(0, ==, ed25519_secret_key_generate(&sec1, 0));
tt_int_op(0, ==, ed25519_secret_key_generate(&sec2, 1));
tt_int_op(0, ==, ed25519_public_key_generate(&pub1, &sec1));
tt_int_op(0, ==, ed25519_public_key_generate(&pub2, &sec1));
test_memeq(pub1.pubkey, pub2.pubkey, sizeof(pub1.pubkey));
memcpy(&kp1.pubkey, &pub1, sizeof(pub1));
memcpy(&kp1.seckey, &sec1, sizeof(sec1));
tt_int_op(0, ==, ed25519_sign(&sig1, msg, msg_len, &kp1));
tt_int_op(0, ==, ed25519_sign(&sig2, msg, msg_len, &kp1));
/* Ed25519 signatures are deterministic */
test_memeq(sig1.sig, sig2.sig, sizeof(sig1.sig));
/* Basic signature is valid. */
tt_int_op(0, ==, ed25519_checksig(&sig1, msg, msg_len, &pub1));
/* Altered signature doesn't work. */
sig1.sig[0] ^= 3;
tt_int_op(-1, ==, ed25519_checksig(&sig1, msg, msg_len, &pub1));
/* Wrong public key doesn't work. */
tt_int_op(0, ==, ed25519_public_key_generate(&pub2, &sec2));
tt_int_op(-1, ==, ed25519_checksig(&sig2, msg, msg_len, &pub2));
/* Wrong message doesn't work. */
tt_int_op(0, ==, ed25519_checksig(&sig2, msg, msg_len, &pub1));
tt_int_op(-1, ==, ed25519_checksig(&sig2, msg, msg_len-1, &pub1));
tt_int_op(-1, ==, ed25519_checksig(&sig2, msg2, msg2_len, &pub1));
/* Batch signature checking works with some bad. */
tt_int_op(0, ==, ed25519_keypair_generate(&kp2, 0));
tt_int_op(0, ==, ed25519_sign(&sig1, msg, msg_len, &kp2));
{
ed25519_checkable_t ch[] = {
{ &pub1, sig2, msg, msg_len }, /*ok*/
{ &pub1, sig2, msg, msg_len-1 }, /*bad*/
{ &kp2.pubkey, sig2, msg2, msg2_len }, /*bad*/
{ &kp2.pubkey, sig1, msg, msg_len }, /*ok*/
};
int okay[4];
tt_int_op(-2, ==, ed25519_checksig_batch(okay, ch, 4));
tt_int_op(okay[0], ==, 1);
tt_int_op(okay[1], ==, 0);
tt_int_op(okay[2], ==, 0);
tt_int_op(okay[3], ==, 1);
tt_int_op(-2, ==, ed25519_checksig_batch(NULL, ch, 4));
}
/* Batch signature checking works with all good. */
{
ed25519_checkable_t ch[] = {
{ &pub1, sig2, msg, msg_len }, /*ok*/
{ &kp2.pubkey, sig1, msg, msg_len }, /*ok*/
};
int okay[2];
tt_int_op(0, ==, ed25519_checksig_batch(okay, ch, 2));
tt_int_op(okay[0], ==, 1);
tt_int_op(okay[1], ==, 1);
tt_int_op(0, ==, ed25519_checksig_batch(NULL, ch, 2));
}
done:
;
}
static void
test_crypto_ed25519_test_vectors(void *arg)
{
char *mem_op_hex_tmp=NULL;
int i;
struct {
const char *sk;
const char *pk;
const char *sig;
const char *msg;
} items[] = {
/* These test vectors were generated with the "ref" implementation of
* ed25519 from SUPERCOP-20130419 */
{ "4c6574277320686f706520746865726520617265206e6f206275677320696e20",
"f3e0e493b30f56e501aeb868fc912fe0c8b76621efca47a78f6d75875193dd87",
"b5d7fd6fd3adf643647ce1fe87a2931dedd1a4e38e6c662bedd35cdd80bfac51"
"1b2c7d1ee6bd929ac213014e1a8dc5373854c7b25dbe15ec96bf6c94196fae06",
"506c6561736520657863757365206d7920667269656e642e2048652069736e2774"
"204e554c2d7465726d696e617465642e"
},
{ "74686520696d706c656d656e746174696f6e20776869636820617265206e6f74",
"407f0025a1e1351a4cb68e92f5c0ebaf66e7aaf93a4006a4d1a66e3ede1cfeac",
"02884fde1c3c5944d0ecf2d133726fc820c303aae695adceabf3a1e01e95bf28"
"da88c0966f5265e9c6f8edc77b3b96b5c91baec3ca993ccd21a3f64203600601",
"506c6561736520657863757365206d7920667269656e642e2048652069736e2774"
"204e554c2d7465726d696e617465642e"
},
{ "6578706f73656420627920456e676c697368207465787420617320696e707574",
"61681cb5fbd69f9bc5a462a21a7ab319011237b940bc781cdc47fcbe327e7706",
"6a127d0414de7510125d4bc214994ffb9b8857a46330832d05d1355e882344ad"
"f4137e3ca1f13eb9cc75c887ef2309b98c57528b4acd9f6376c6898889603209",
"506c6561736520657863757365206d7920667269656e642e2048652069736e2774"
"204e554c2d7465726d696e617465642e"
},
/* These come from "sign.input" in ed25519's page */
{ "5b5a619f8ce1c66d7ce26e5a2ae7b0c04febcd346d286c929e19d0d5973bfef9",
"6fe83693d011d111131c4f3fbaaa40a9d3d76b30012ff73bb0e39ec27ab18257",
"0f9ad9793033a2fa06614b277d37381e6d94f65ac2a5a94558d09ed6ce922258"
"c1a567952e863ac94297aec3c0d0c8ddf71084e504860bb6ba27449b55adc40e",
"5a8d9d0a22357e6655f9c785"
},
{ "940c89fe40a81dafbdb2416d14ae469119869744410c3303bfaa0241dac57800",
"a2eb8c0501e30bae0cf842d2bde8dec7386f6b7fc3981b8c57c9792bb94cf2dd",
"d8bb64aad8c9955a115a793addd24f7f2b077648714f49c4694ec995b330d09d"
"640df310f447fd7b6cb5c14f9fe9f490bcf8cfadbfd2169c8ac20d3b8af49a0c",
"b87d3813e03f58cf19fd0b6395"
},
{ "9acad959d216212d789a119252ebfe0c96512a23c73bd9f3b202292d6916a738",
"cf3af898467a5b7a52d33d53bc037e2642a8da996903fc252217e9c033e2f291",
"6ee3fe81e23c60eb2312b2006b3b25e6838e02106623f844c44edb8dafd66ab0"
"671087fd195df5b8f58a1d6e52af42908053d55c7321010092748795ef94cf06",
"55c7fa434f5ed8cdec2b7aeac173",
},
{ "d5aeee41eeb0e9d1bf8337f939587ebe296161e6bf5209f591ec939e1440c300",
"fd2a565723163e29f53c9de3d5e8fbe36a7ab66e1439ec4eae9c0a604af291a5",
"f68d04847e5b249737899c014d31c805c5007a62c0a10d50bb1538c5f3550395"
"1fbc1e08682f2cc0c92efe8f4985dec61dcbd54d4b94a22547d24451271c8b00",
"0a688e79be24f866286d4646b5d81c"
},
{ NULL, NULL, NULL, NULL}
};
(void)arg;
for (i = 0; items[i].pk; ++i) {
ed25519_keypair_t kp;
ed25519_signature_t sig;
uint8_t *msg;
size_t msg_len;
base16_decode((char*)kp.seckey.seckey, sizeof(kp.seckey.seckey),
items[i].sk, 64);
tt_int_op(0, ==, ed25519_public_key_generate(&kp.pubkey, &kp.seckey));
test_memeq_hex(kp.pubkey.pubkey, items[i].pk);
msg_len = strlen(items[i].msg) / 2;
msg = tor_malloc(msg_len);
base16_decode((char*)msg, msg_len, items[i].msg, strlen(items[i].msg));
tt_int_op(0, ==, ed25519_sign(&sig, msg, msg_len, &kp));
test_memeq_hex(sig.sig, items[i].sig);
tor_free(msg);
}
done:
tor_free(mem_op_hex_tmp);
}
/* XXX
Check known values for secret->public, for public,msg->signature.
*/
#endif
static void
@ -1300,6 +1483,8 @@ struct testcase_t crypto_tests[] = {
{ "curve25519_wrappers", test_crypto_curve25519_wrappers, 0, NULL, NULL },
{ "curve25519_encode", test_crypto_curve25519_encode, 0, NULL, NULL },
{ "curve25519_persist", test_crypto_curve25519_persist, 0, NULL, NULL },
{ "ed25519_simple", test_crypto_ed25519_simple, 0, NULL, NULL },
{ "ed25519_test_vectors", test_crypto_ed25519_test_vectors, 0, NULL, NULL },
#endif
{ "siphash", test_crypto_siphash, 0, NULL, NULL },
END_OF_TESTCASES