Mercurial > dropbear
view libtomcrypt/testprof/ecc_test.c @ 1788:1fc0012b9c38
Fix handling of replies to global requests (#112)
The current code assumes that all global requests want / need a reply.
This isn't always true and the request itself indicates if it wants a
reply or not.
It causes a specific problem with [email protected] messages.
These are sent by OpenSSH after authentication to inform the client of
potential other host keys for the host. This can be used to add a new
type of host key or to rotate host keys.
The initial information message from the server is sent as a global
request, but with want_reply set to false. This means that the server
doesn't expect an answer to this message. Instead the client needs to
send a prove request as a reply if it wants to receive proof of
ownership for the host keys.
The bug doesn't cause any current problems with due to how OpenSSH
treats receiving the failure message. It instead treats it as a
keepalive message and further ignores it.
Arguably this is a protocol violation though of Dropbear and it is only
accidental that it doesn't cause a problem with OpenSSH.
The bug was found when adding host keys support to libssh, which is more
strict protocol wise and treats the unexpected failure message an error,
also see https://gitlab.com/libssh/libssh-mirror/-/merge_requests/145
for more information.
The fix here is to honor the want_reply flag in the global request and
to only send a reply if the other side expects a reply.
author | Dirkjan Bussink <d.bussink@gmail.com> |
---|---|
date | Thu, 10 Dec 2020 16:13:13 +0100 |
parents | f849a5ca2efc |
children |
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#include <tomcrypt_test.h> #ifdef LTC_MECC static int sizes[] = { #ifdef ECC112 14, #endif #ifdef ECC128 16, #endif #ifdef ECC160 20, #endif #ifdef ECC192 24, #endif #ifdef ECC224 28, #endif #ifdef ECC256 32, #endif #ifdef ECC384 48, #endif #ifdef ECC521 65 #endif }; #ifdef LTC_ECC_SHAMIR int ecc_test_shamir(void) { void *modulus, *mp, *kA, *kB, *rA, *rB; ecc_point *G, *A, *B, *C1, *C2; int x, y, z; unsigned char buf[ECC_BUF_SIZE]; DO(mp_init_multi(&kA, &kB, &rA, &rB, &modulus, NULL)); LTC_ARGCHK((G = ltc_ecc_new_point()) != NULL); LTC_ARGCHK((A = ltc_ecc_new_point()) != NULL); LTC_ARGCHK((B = ltc_ecc_new_point()) != NULL); LTC_ARGCHK((C1 = ltc_ecc_new_point()) != NULL); LTC_ARGCHK((C2 = ltc_ecc_new_point()) != NULL); for (x = 0; x < (int)(sizeof(sizes)/sizeof(sizes[0])); x++) { /* get the base point */ for (z = 0; ltc_ecc_sets[z].name; z++) { if (sizes[z] < ltc_ecc_sets[z].size) break; } LTC_ARGCHK(ltc_ecc_sets[z].name != NULL); /* load it */ DO(mp_read_radix(G->x, ltc_ecc_sets[z].Gx, 16)); DO(mp_read_radix(G->y, ltc_ecc_sets[z].Gy, 16)); DO(mp_set(G->z, 1)); DO(mp_read_radix(modulus, ltc_ecc_sets[z].prime, 16)); DO(mp_montgomery_setup(modulus, &mp)); /* do 100 random tests */ for (y = 0; y < 100; y++) { /* pick a random r1, r2 */ LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]); DO(mp_read_unsigned_bin(rA, buf, sizes[x])); LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]); DO(mp_read_unsigned_bin(rB, buf, sizes[x])); /* compute rA * G = A */ DO(ltc_mp.ecc_ptmul(rA, G, A, modulus, 1)); /* compute rB * G = B */ DO(ltc_mp.ecc_ptmul(rB, G, B, modulus, 1)); /* pick a random kA, kB */ LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]); DO(mp_read_unsigned_bin(kA, buf, sizes[x])); LTC_ARGCHK(yarrow_read(buf, sizes[x], &yarrow_prng) == sizes[x]); DO(mp_read_unsigned_bin(kB, buf, sizes[x])); /* now, compute kA*A + kB*B = C1 using the older method */ DO(ltc_mp.ecc_ptmul(kA, A, C1, modulus, 0)); DO(ltc_mp.ecc_ptmul(kB, B, C2, modulus, 0)); DO(ltc_mp.ecc_ptadd(C1, C2, C1, modulus, mp)); DO(ltc_mp.ecc_map(C1, modulus, mp)); /* now compute using mul2add */ DO(ltc_mp.ecc_mul2add(A, kA, B, kB, C2, modulus)); /* is they the sames? */ if ((mp_cmp(C1->x, C2->x) != LTC_MP_EQ) || (mp_cmp(C1->y, C2->y) != LTC_MP_EQ) || (mp_cmp(C1->z, C2->z) != LTC_MP_EQ)) { fprintf(stderr, "ECC failed shamir test: size=%d, testno=%d\n", sizes[x], y); return 1; } } mp_montgomery_free(mp); } ltc_ecc_del_point(C2); ltc_ecc_del_point(C1); ltc_ecc_del_point(B); ltc_ecc_del_point(A); ltc_ecc_del_point(G); mp_clear_multi(kA, kB, rA, rB, modulus, NULL); return 0; } #endif int ecc_tests (void) { unsigned char buf[4][4096]; unsigned long x, y, z, s; int stat, stat2; ecc_key usera, userb, pubKey, privKey; DO(ecc_test ()); DO(ecc_test ()); DO(ecc_test ()); DO(ecc_test ()); DO(ecc_test ()); for (s = 0; s < (sizeof(sizes)/sizeof(sizes[0])); s++) { /* make up two keys */ DO(ecc_make_key (&yarrow_prng, find_prng ("yarrow"), sizes[s], &usera)); DO(ecc_make_key (&yarrow_prng, find_prng ("yarrow"), sizes[s], &userb)); /* make the shared secret */ x = sizeof(buf[0]); DO(ecc_shared_secret (&usera, &userb, buf[0], &x)); y = sizeof(buf[1]); DO(ecc_shared_secret (&userb, &usera, buf[1], &y)); if (y != x) { fprintf(stderr, "ecc Shared keys are not same size."); return 1; } if (memcmp (buf[0], buf[1], x)) { fprintf(stderr, "ecc Shared keys not same contents."); return 1; } /* now export userb */ y = sizeof(buf[0]); DO(ecc_export (buf[1], &y, PK_PUBLIC, &userb)); ecc_free (&userb); /* import and make the shared secret again */ DO(ecc_import (buf[1], y, &userb)); z = sizeof(buf[0]); DO(ecc_shared_secret (&usera, &userb, buf[2], &z)); if (z != x) { fprintf(stderr, "failed. Size don't match?"); return 1; } if (memcmp (buf[0], buf[2], x)) { fprintf(stderr, "Failed. Contents didn't match."); return 1; } /* export with ANSI X9.63 */ y = sizeof(buf[1]); DO(ecc_ansi_x963_export(&userb, buf[1], &y)); ecc_free (&userb); /* now import the ANSI key */ DO(ecc_ansi_x963_import(buf[1], y, &userb)); /* shared secret */ z = sizeof(buf[0]); DO(ecc_shared_secret (&usera, &userb, buf[2], &z)); if (z != x) { fprintf(stderr, "failed. Size don't match?"); return 1; } if (memcmp (buf[0], buf[2], x)) { fprintf(stderr, "Failed. Contents didn't match."); return 1; } ecc_free (&usera); ecc_free (&userb); /* test encrypt_key */ DO(ecc_make_key (&yarrow_prng, find_prng ("yarrow"), sizes[s], &usera)); /* export key */ x = sizeof(buf[0]); DO(ecc_export(buf[0], &x, PK_PUBLIC, &usera)); DO(ecc_import(buf[0], x, &pubKey)); x = sizeof(buf[0]); DO(ecc_export(buf[0], &x, PK_PRIVATE, &usera)); DO(ecc_import(buf[0], x, &privKey)); for (x = 0; x < 32; x++) { buf[0][x] = x; } y = sizeof (buf[1]); DO(ecc_encrypt_key (buf[0], 32, buf[1], &y, &yarrow_prng, find_prng ("yarrow"), find_hash ("sha256"), &pubKey)); zeromem (buf[0], sizeof (buf[0])); x = sizeof (buf[0]); DO(ecc_decrypt_key (buf[1], y, buf[0], &x, &privKey)); if (x != 32) { fprintf(stderr, "Failed (length)"); return 1; } for (x = 0; x < 32; x++) { if (buf[0][x] != x) { fprintf(stderr, "Failed (contents)"); return 1; } } /* test sign_hash */ for (x = 0; x < 16; x++) { buf[0][x] = x; } x = sizeof (buf[1]); DO(ecc_sign_hash (buf[0], 16, buf[1], &x, &yarrow_prng, find_prng ("yarrow"), &privKey)); DO(ecc_verify_hash (buf[1], x, buf[0], 16, &stat, &pubKey)); buf[0][0] ^= 1; DO(ecc_verify_hash (buf[1], x, buf[0], 16, &stat2, &privKey)); if (!(stat == 1 && stat2 == 0)) { fprintf(stderr, "ecc_verify_hash failed %d, %d, ", stat, stat2); return 1; } ecc_free (&usera); ecc_free (&pubKey); ecc_free (&privKey); } #ifdef LTC_ECC_SHAMIR return ecc_test_shamir(); #else return 0; #endif } #else int ecc_tests(void) { fprintf(stderr, "NOP"); return 0; } #endif /* $Source$ */ /* $Revision$ */ /* $Date$ */