Mercurial > dropbear
view libtomcrypt/testprof/modes_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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/* test CFB/OFB/CBC modes */ #include <tomcrypt_test.h> int modes_test(void) { unsigned char pt[64], ct[64], tmp[64], key[16], iv[16], iv2[16]; int cipher_idx; #ifdef LTC_CBC_MODE symmetric_CBC cbc; #endif #ifdef LTC_CFB_MODE symmetric_CFB cfb; #endif #ifdef LTC_OFB_MODE symmetric_OFB ofb; #endif unsigned long l; /* make a random pt, key and iv */ yarrow_read(pt, 64, &yarrow_prng); yarrow_read(key, 16, &yarrow_prng); yarrow_read(iv, 16, &yarrow_prng); /* get idx of AES handy */ cipher_idx = find_cipher("aes"); if (cipher_idx == -1) { fprintf(stderr, "test requires AES"); return 1; } #ifdef LTC_F8_MODE DO(f8_test_mode()); #endif #ifdef LTC_LRW_MODE DO(lrw_test()); #endif #ifdef LTC_CBC_MODE /* test CBC mode */ /* encode the block */ DO(cbc_start(cipher_idx, iv, key, 16, 0, &cbc)); l = sizeof(iv2); DO(cbc_getiv(iv2, &l, &cbc)); if (l != 16 || memcmp(iv2, iv, 16)) { fprintf(stderr, "cbc_getiv failed"); return 1; } DO(cbc_encrypt(pt, ct, 64, &cbc)); /* decode the block */ DO(cbc_setiv(iv2, l, &cbc)); zeromem(tmp, sizeof(tmp)); DO(cbc_decrypt(ct, tmp, 64, &cbc)); if (memcmp(tmp, pt, 64) != 0) { fprintf(stderr, "CBC failed"); return 1; } #endif #ifdef LTC_CFB_MODE /* test CFB mode */ /* encode the block */ DO(cfb_start(cipher_idx, iv, key, 16, 0, &cfb)); l = sizeof(iv2); DO(cfb_getiv(iv2, &l, &cfb)); /* note we don't memcmp iv2/iv since cfb_start processes the IV for the first block */ if (l != 16) { fprintf(stderr, "cfb_getiv failed"); return 1; } DO(cfb_encrypt(pt, ct, 64, &cfb)); /* decode the block */ DO(cfb_setiv(iv, l, &cfb)); zeromem(tmp, sizeof(tmp)); DO(cfb_decrypt(ct, tmp, 64, &cfb)); if (memcmp(tmp, pt, 64) != 0) { fprintf(stderr, "CFB failed"); return 1; } #endif #ifdef LTC_OFB_MODE /* test OFB mode */ /* encode the block */ DO(ofb_start(cipher_idx, iv, key, 16, 0, &ofb)); l = sizeof(iv2); DO(ofb_getiv(iv2, &l, &ofb)); if (l != 16 || memcmp(iv2, iv, 16)) { fprintf(stderr, "ofb_getiv failed"); return 1; } DO(ofb_encrypt(pt, ct, 64, &ofb)); /* decode the block */ DO(ofb_setiv(iv2, l, &ofb)); zeromem(tmp, sizeof(tmp)); DO(ofb_decrypt(ct, tmp, 64, &ofb)); if (memcmp(tmp, pt, 64) != 0) { fprintf(stderr, "OFB failed"); return 1; } #endif #ifdef LTC_CTR_MODE DO(ctr_test()); #endif #ifdef LTC_XTS_MODE DO(xts_test()); #endif return 0; } /* $Source$ */ /* $Revision$ */ /* $Date$ */