mirror of
https://github.com/clearml/dropbear
synced 2025-04-26 00:49:39 +00:00
- Get rid of decryptreadbuf, just decrypt in-place with readbuf
- Share make_mac function for both packet creation and validation - Split recv/trans parts of key_context into their own structures --HG-- extra : convert_revision : 043bc598c76ed43625987e6937e32238f7ed6240
This commit is contained in:
Matt Johnston
parent
8e72bbaa9d
commit
ff763e4005
114
common-kex.c
114
common-kex.c
@ -272,8 +272,8 @@ void gen_new_keys() {
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recv_IV = S2C_IV;
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trans_key = C2S_key;
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recv_key = S2C_key;
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C2S_keysize = ses.newkeys->trans_algo_crypt->keysize;
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S2C_keysize = ses.newkeys->recv_algo_crypt->keysize;
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C2S_keysize = ses.newkeys->trans.algo_crypt->keysize;
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S2C_keysize = ses.newkeys->recv.algo_crypt->keysize;
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mactransletter = 'E';
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macrecvletter = 'F';
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} else {
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@ -281,8 +281,8 @@ void gen_new_keys() {
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recv_IV = C2S_IV;
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trans_key = S2C_key;
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recv_key = C2S_key;
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C2S_keysize = ses.newkeys->recv_algo_crypt->keysize;
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S2C_keysize = ses.newkeys->trans_algo_crypt->keysize;
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C2S_keysize = ses.newkeys->recv.algo_crypt->keysize;
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S2C_keysize = ses.newkeys->trans.algo_crypt->keysize;
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mactransletter = 'F';
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macrecvletter = 'E';
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}
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@ -292,31 +292,33 @@ void gen_new_keys() {
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hashkeys(C2S_key, C2S_keysize, &hs, 'C');
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hashkeys(S2C_key, S2C_keysize, &hs, 'D');
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recv_cipher = find_cipher(ses.newkeys->recv_algo_crypt->cipherdesc->name);
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recv_cipher = find_cipher(ses.newkeys->recv.algo_crypt->cipherdesc->name);
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if (recv_cipher < 0)
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dropbear_exit("crypto error");
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if (ses.newkeys->recv_crypt_mode->start(recv_cipher,
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if (ses.newkeys->recv.crypt_mode->start(recv_cipher,
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recv_IV, recv_key,
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ses.newkeys->recv_algo_crypt->keysize, 0,
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&ses.newkeys->recv_cipher_state) != CRYPT_OK) {
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ses.newkeys->recv.algo_crypt->keysize, 0,
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&ses.newkeys->recv.cipher_state) != CRYPT_OK) {
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dropbear_exit("crypto error");
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}
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trans_cipher = find_cipher(ses.newkeys->trans_algo_crypt->cipherdesc->name);
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trans_cipher = find_cipher(ses.newkeys->trans.algo_crypt->cipherdesc->name);
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if (trans_cipher < 0)
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dropbear_exit("crypto error");
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if (ses.newkeys->trans_crypt_mode->start(trans_cipher,
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if (ses.newkeys->trans.crypt_mode->start(trans_cipher,
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trans_IV, trans_key,
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ses.newkeys->trans_algo_crypt->keysize, 0,
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&ses.newkeys->trans_cipher_state) != CRYPT_OK) {
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ses.newkeys->trans.algo_crypt->keysize, 0,
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&ses.newkeys->trans.cipher_state) != CRYPT_OK) {
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dropbear_exit("crypto error");
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}
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/* MAC keys */
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hashkeys(ses.newkeys->transmackey,
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ses.newkeys->trans_algo_mac->keysize, &hs, mactransletter);
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hashkeys(ses.newkeys->recvmackey,
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ses.newkeys->recv_algo_mac->keysize, &hs, macrecvletter);
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hashkeys(ses.newkeys->trans.mackey,
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ses.newkeys->trans.algo_mac->keysize, &hs, mactransletter);
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hashkeys(ses.newkeys->recv.mackey,
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ses.newkeys->recv.algo_mac->keysize, &hs, macrecvletter);
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ses.newkeys->trans.hash_index = find_hash(ses.newkeys->trans.algo_mac->hashdesc->name),
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ses.newkeys->recv.hash_index = find_hash(ses.newkeys->recv.algo_mac->hashdesc->name),
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#ifndef DISABLE_ZLIB
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gen_new_zstreams();
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@ -334,15 +336,15 @@ void gen_new_keys() {
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#ifndef DISABLE_ZLIB
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int is_compress_trans() {
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return ses.keys->trans_algo_comp == DROPBEAR_COMP_ZLIB
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return ses.keys->trans.algo_comp == DROPBEAR_COMP_ZLIB
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|| (ses.authstate.authdone
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&& ses.keys->trans_algo_comp == DROPBEAR_COMP_ZLIB_DELAY);
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&& ses.keys->trans.algo_comp == DROPBEAR_COMP_ZLIB_DELAY);
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}
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int is_compress_recv() {
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return ses.keys->recv_algo_comp == DROPBEAR_COMP_ZLIB
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return ses.keys->recv.algo_comp == DROPBEAR_COMP_ZLIB
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|| (ses.authstate.authdone
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&& ses.keys->recv_algo_comp == DROPBEAR_COMP_ZLIB_DELAY);
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&& ses.keys->recv.algo_comp == DROPBEAR_COMP_ZLIB_DELAY);
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}
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/* Set up new zlib compression streams, close the old ones. Only
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@ -350,47 +352,47 @@ int is_compress_recv() {
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static void gen_new_zstreams() {
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/* create new zstreams */
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if (ses.newkeys->recv_algo_comp == DROPBEAR_COMP_ZLIB
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|| ses.newkeys->recv_algo_comp == DROPBEAR_COMP_ZLIB_DELAY) {
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ses.newkeys->recv_zstream = (z_streamp)m_malloc(sizeof(z_stream));
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ses.newkeys->recv_zstream->zalloc = Z_NULL;
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ses.newkeys->recv_zstream->zfree = Z_NULL;
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if (ses.newkeys->recv.algo_comp == DROPBEAR_COMP_ZLIB
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|| ses.newkeys->recv.algo_comp == DROPBEAR_COMP_ZLIB_DELAY) {
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ses.newkeys->recv.zstream = (z_streamp)m_malloc(sizeof(z_stream));
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ses.newkeys->recv.zstream->zalloc = Z_NULL;
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ses.newkeys->recv.zstream->zfree = Z_NULL;
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if (inflateInit(ses.newkeys->recv_zstream) != Z_OK) {
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if (inflateInit(ses.newkeys->recv.zstream) != Z_OK) {
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dropbear_exit("zlib error");
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}
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} else {
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ses.newkeys->recv_zstream = NULL;
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ses.newkeys->recv.zstream = NULL;
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}
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if (ses.newkeys->trans_algo_comp == DROPBEAR_COMP_ZLIB
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|| ses.newkeys->trans_algo_comp == DROPBEAR_COMP_ZLIB_DELAY) {
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ses.newkeys->trans_zstream = (z_streamp)m_malloc(sizeof(z_stream));
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ses.newkeys->trans_zstream->zalloc = Z_NULL;
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ses.newkeys->trans_zstream->zfree = Z_NULL;
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if (ses.newkeys->trans.algo_comp == DROPBEAR_COMP_ZLIB
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|| ses.newkeys->trans.algo_comp == DROPBEAR_COMP_ZLIB_DELAY) {
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ses.newkeys->trans.zstream = (z_streamp)m_malloc(sizeof(z_stream));
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ses.newkeys->trans.zstream->zalloc = Z_NULL;
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ses.newkeys->trans.zstream->zfree = Z_NULL;
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if (deflateInit(ses.newkeys->trans_zstream, Z_DEFAULT_COMPRESSION)
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if (deflateInit(ses.newkeys->trans.zstream, Z_DEFAULT_COMPRESSION)
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!= Z_OK) {
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dropbear_exit("zlib error");
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}
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} else {
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ses.newkeys->trans_zstream = NULL;
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ses.newkeys->trans.zstream = NULL;
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}
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/* clean up old keys */
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if (ses.keys->recv_zstream != NULL) {
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if (inflateEnd(ses.keys->recv_zstream) == Z_STREAM_ERROR) {
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if (ses.keys->recv.zstream != NULL) {
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if (inflateEnd(ses.keys->recv.zstream) == Z_STREAM_ERROR) {
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/* Z_DATA_ERROR is ok, just means that stream isn't ended */
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dropbear_exit("crypto error");
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}
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m_free(ses.keys->recv_zstream);
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m_free(ses.keys->recv.zstream);
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}
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if (ses.keys->trans_zstream != NULL) {
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if (deflateEnd(ses.keys->trans_zstream) == Z_STREAM_ERROR) {
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if (ses.keys->trans.zstream != NULL) {
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if (deflateEnd(ses.keys->trans.zstream) == Z_STREAM_ERROR) {
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/* Z_DATA_ERROR is ok, just means that stream isn't ended */
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dropbear_exit("crypto error");
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}
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m_free(ses.keys->trans_zstream);
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m_free(ses.keys->trans.zstream);
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}
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}
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#endif /* DISABLE_ZLIB */
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@ -698,36 +700,36 @@ static void read_kex_algos() {
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/* Handle the asymmetry */
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if (IS_DROPBEAR_CLIENT) {
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ses.newkeys->recv_algo_crypt =
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ses.newkeys->recv.algo_crypt =
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(struct dropbear_cipher*)s2c_cipher_algo->data;
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ses.newkeys->trans_algo_crypt =
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ses.newkeys->trans.algo_crypt =
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(struct dropbear_cipher*)c2s_cipher_algo->data;
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ses.newkeys->recv_crypt_mode =
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ses.newkeys->recv.crypt_mode =
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(struct dropbear_cipher_mode*)s2c_cipher_algo->mode;
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ses.newkeys->trans_crypt_mode =
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ses.newkeys->trans.crypt_mode =
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(struct dropbear_cipher_mode*)c2s_cipher_algo->mode;
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ses.newkeys->recv_algo_mac =
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ses.newkeys->recv.algo_mac =
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(struct dropbear_hash*)s2c_hash_algo->data;
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ses.newkeys->trans_algo_mac =
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ses.newkeys->trans.algo_mac =
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(struct dropbear_hash*)c2s_hash_algo->data;
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ses.newkeys->recv_algo_comp = s2c_comp_algo->val;
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ses.newkeys->trans_algo_comp = c2s_comp_algo->val;
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ses.newkeys->recv.algo_comp = s2c_comp_algo->val;
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ses.newkeys->trans.algo_comp = c2s_comp_algo->val;
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} else {
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/* SERVER */
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ses.newkeys->recv_algo_crypt =
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ses.newkeys->recv.algo_crypt =
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(struct dropbear_cipher*)c2s_cipher_algo->data;
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ses.newkeys->trans_algo_crypt =
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ses.newkeys->trans.algo_crypt =
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(struct dropbear_cipher*)s2c_cipher_algo->data;
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ses.newkeys->recv_crypt_mode =
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ses.newkeys->recv.crypt_mode =
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(struct dropbear_cipher_mode*)c2s_cipher_algo->mode;
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ses.newkeys->trans_crypt_mode =
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ses.newkeys->trans.crypt_mode =
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(struct dropbear_cipher_mode*)s2c_cipher_algo->mode;
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ses.newkeys->recv_algo_mac =
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ses.newkeys->recv.algo_mac =
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(struct dropbear_hash*)c2s_hash_algo->data;
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ses.newkeys->trans_algo_mac =
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ses.newkeys->trans.algo_mac =
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(struct dropbear_hash*)s2c_hash_algo->data;
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ses.newkeys->recv_algo_comp = c2s_comp_algo->val;
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ses.newkeys->trans_algo_comp = s2c_comp_algo->val;
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ses.newkeys->recv.algo_comp = c2s_comp_algo->val;
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ses.newkeys->trans.algo_comp = s2c_comp_algo->val;
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}
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/* reserved for future extensions */
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@ -78,7 +78,6 @@ void common_session_init(int sock_in, int sock_out, char* remotehost) {
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ses.transseq = 0;
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ses.readbuf = NULL;
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ses.decryptreadbuf = NULL;
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ses.payload = NULL;
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ses.recvseq = 0;
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@ -95,22 +94,22 @@ void common_session_init(int sock_in, int sock_out, char* remotehost) {
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/* set all the algos to none */
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ses.keys = (struct key_context*)m_malloc(sizeof(struct key_context));
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ses.newkeys = NULL;
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ses.keys->recv_algo_crypt = &dropbear_nocipher;
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ses.keys->trans_algo_crypt = &dropbear_nocipher;
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ses.keys->recv_crypt_mode = &dropbear_mode_none;
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ses.keys->trans_crypt_mode = &dropbear_mode_none;
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ses.keys->recv.algo_crypt = &dropbear_nocipher;
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ses.keys->trans.algo_crypt = &dropbear_nocipher;
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ses.keys->recv.crypt_mode = &dropbear_mode_none;
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ses.keys->trans.crypt_mode = &dropbear_mode_none;
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ses.keys->recv_algo_mac = &dropbear_nohash;
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ses.keys->trans_algo_mac = &dropbear_nohash;
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ses.keys->recv.algo_mac = &dropbear_nohash;
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ses.keys->trans.algo_mac = &dropbear_nohash;
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ses.keys->algo_kex = -1;
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ses.keys->algo_hostkey = -1;
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ses.keys->recv_algo_comp = DROPBEAR_COMP_NONE;
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ses.keys->trans_algo_comp = DROPBEAR_COMP_NONE;
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ses.keys->recv.algo_comp = DROPBEAR_COMP_NONE;
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ses.keys->trans.algo_comp = DROPBEAR_COMP_NONE;
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#ifndef DISABLE_ZLIB
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ses.keys->recv_zstream = NULL;
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ses.keys->trans_zstream = NULL;
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ses.keys->recv.zstream = NULL;
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ses.keys->trans.zstream = NULL;
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#endif
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/* key exchange buffers */
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198
packet.c
198
packet.c
@ -35,9 +35,11 @@
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#include "auth.h"
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#include "channel.h"
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static void read_packet_init();
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static void make_mac(buffer * clearwritebuf, unsigned char *output_mac);
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static int checkmac(buffer* hashbuf, buffer* readbuf);
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static int read_packet_init();
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static void make_mac(unsigned int seqno, const struct key_context_directional * key_state,
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buffer * clear_buf, unsigned int clear_len,
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unsigned char *output_mac);
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static int checkmac();
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#define ZLIB_COMPRESS_INCR 20 /* this is 12 bytes + 0.1% of 8000 bytes */
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#define ZLIB_DECOMPRESS_INCR 100
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@ -102,18 +104,18 @@ void read_packet() {
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unsigned char blocksize;
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TRACE(("enter read_packet"))
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blocksize = ses.keys->recv_algo_crypt->blocksize;
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blocksize = ses.keys->recv.algo_crypt->blocksize;
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if (ses.readbuf == NULL || ses.readbuf->len < blocksize) {
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int ret;
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/* In the first blocksize of a packet */
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/* Read the first blocksize of the packet, so we can decrypt it and
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* find the length of the whole packet */
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read_packet_init();
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ret = read_packet_init();
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/* If we don't have the length of decryptreadbuf, we didn't read
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* a whole blocksize and should exit */
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if (ses.decryptreadbuf->len == 0) {
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if (ret == DROPBEAR_FAILURE) {
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/* didn't read enough to determine the length */
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TRACE(("leave read_packet: packetinit done"))
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return;
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}
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@ -121,7 +123,6 @@ void read_packet() {
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/* Attempt to read the remainder of the packet, note that there
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* mightn't be any available (EAGAIN) */
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dropbear_assert(ses.readbuf != NULL);
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maxlen = ses.readbuf->len - ses.readbuf->pos;
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len = read(ses.sock_in, buf_getptr(ses.readbuf, maxlen), maxlen);
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@ -151,7 +152,9 @@ void read_packet() {
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/* Function used to read the initial portion of a packet, and determine the
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* length. Only called during the first BLOCKSIZE of a packet. */
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static void read_packet_init() {
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/* Returns DROPBEAR_SUCCESS if the length is determined,
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* DROPBEAR_FAILURE otherwise */
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static int read_packet_init() {
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unsigned int maxlen;
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int len;
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@ -159,14 +162,12 @@ static void read_packet_init() {
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unsigned char macsize;
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blocksize = ses.keys->recv_algo_crypt->blocksize;
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macsize = ses.keys->recv_algo_mac->hashsize;
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blocksize = ses.keys->recv.algo_crypt->blocksize;
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macsize = ses.keys->recv.algo_mac->hashsize;
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if (ses.readbuf == NULL) {
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/* start of a new packet */
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ses.readbuf = buf_new(INIT_READBUF);
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dropbear_assert(ses.decryptreadbuf == NULL);
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ses.decryptreadbuf = buf_new(blocksize);
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}
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maxlen = blocksize - ses.readbuf->pos;
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@ -180,7 +181,7 @@ static void read_packet_init() {
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if (len < 0) {
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if (errno == EINTR) {
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TRACE(("leave read_packet_init: EINTR"))
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return;
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return DROPBEAR_FAILURE;
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}
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dropbear_exit("error reading: %s", strerror(errno));
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}
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@ -189,22 +190,22 @@ static void read_packet_init() {
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if ((unsigned int)len != maxlen) {
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/* don't have enough bytes to determine length, get next time */
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return;
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return DROPBEAR_FAILURE;
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}
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/* now we have the first block, need to get packet length, so we decrypt
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* the first block (only need first 4 bytes) */
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buf_setpos(ses.readbuf, 0);
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if (ses.keys->recv_crypt_mode->decrypt(buf_getptr(ses.readbuf, blocksize),
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buf_getwriteptr(ses.decryptreadbuf,blocksize),
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if (ses.keys->recv.crypt_mode->decrypt(buf_getptr(ses.readbuf, blocksize),
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buf_getwriteptr(ses.readbuf, blocksize),
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blocksize,
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&ses.keys->recv_cipher_state) != CRYPT_OK) {
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&ses.keys->recv.cipher_state) != CRYPT_OK) {
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dropbear_exit("error decrypting");
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}
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buf_setlen(ses.decryptreadbuf, blocksize);
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len = buf_getint(ses.decryptreadbuf) + 4 + macsize;
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len = buf_getint(ses.readbuf) + 4 + macsize;
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TRACE(("packet size is %d, block %d mac %d", len, blocksize, macsize))
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buf_setpos(ses.readbuf, blocksize);
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/* check packet length */
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if ((len > RECV_MAX_PACKET_LEN) ||
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@ -213,9 +214,12 @@ static void read_packet_init() {
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dropbear_exit("bad packet size %d", len);
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}
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buf_resize(ses.readbuf, len);
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if (len > ses.readbuf->size) {
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buf_resize(ses.readbuf, len);
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}
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buf_setlen(ses.readbuf, len);
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buf_setpos(ses.readbuf, blocksize);
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return DROPBEAR_SUCCESS;
|
||||
}
|
||||
|
||||
/* handle the received packet */
|
||||
@ -227,68 +231,60 @@ void decrypt_packet() {
|
||||
unsigned int len;
|
||||
|
||||
TRACE(("enter decrypt_packet"))
|
||||
blocksize = ses.keys->recv_algo_crypt->blocksize;
|
||||
macsize = ses.keys->recv_algo_mac->hashsize;
|
||||
blocksize = ses.keys->recv.algo_crypt->blocksize;
|
||||
macsize = ses.keys->recv.algo_mac->hashsize;
|
||||
|
||||
ses.kexstate.datarecv += ses.readbuf->len;
|
||||
|
||||
/* we've already decrypted the first blocksize in read_packet_init */
|
||||
buf_setpos(ses.readbuf, blocksize);
|
||||
|
||||
buf_resize(ses.decryptreadbuf, ses.readbuf->len - macsize);
|
||||
buf_setlen(ses.decryptreadbuf, ses.decryptreadbuf->size);
|
||||
buf_setpos(ses.decryptreadbuf, blocksize);
|
||||
|
||||
/* decrypt it */
|
||||
/* decrypt it in-place */
|
||||
len = ses.readbuf->len - macsize - ses.readbuf->pos;
|
||||
if (ses.keys->recv_crypt_mode->decrypt(
|
||||
if (ses.keys->recv.crypt_mode->decrypt(
|
||||
buf_getptr(ses.readbuf, len),
|
||||
buf_getwriteptr(ses.decryptreadbuf, len),
|
||||
buf_getwriteptr(ses.readbuf, len),
|
||||
len,
|
||||
&ses.keys->recv_cipher_state) != CRYPT_OK) {
|
||||
&ses.keys->recv.cipher_state) != CRYPT_OK) {
|
||||
dropbear_exit("error decrypting");
|
||||
}
|
||||
buf_incrpos(ses.readbuf, len);
|
||||
buf_incrwritepos(ses.decryptreadbuf, len);
|
||||
|
||||
printhex("readbuf decrypted", ses.readbuf->data, ses.readbuf->len);
|
||||
|
||||
/* check the hmac */
|
||||
buf_setpos(ses.readbuf, ses.readbuf->len - macsize);
|
||||
if (checkmac(ses.readbuf, ses.decryptreadbuf) != DROPBEAR_SUCCESS) {
|
||||
if (checkmac() != DROPBEAR_SUCCESS) {
|
||||
dropbear_exit("Integrity error");
|
||||
}
|
||||
|
||||
/* readbuf no longer required */
|
||||
buf_free(ses.readbuf);
|
||||
ses.readbuf = NULL;
|
||||
|
||||
/* get padding length */
|
||||
buf_setpos(ses.decryptreadbuf, PACKET_PADDING_OFF);
|
||||
padlen = buf_getbyte(ses.decryptreadbuf);
|
||||
buf_setpos(ses.readbuf, PACKET_PADDING_OFF);
|
||||
padlen = buf_getbyte(ses.readbuf);
|
||||
|
||||
/* payload length */
|
||||
/* - 4 - 1 is for LEN and PADLEN values */
|
||||
len = ses.decryptreadbuf->len - padlen - 4 - 1;
|
||||
len = ses.readbuf->len - padlen - 4 - 1;
|
||||
if ((len > RECV_MAX_PAYLOAD_LEN) || (len < 1)) {
|
||||
dropbear_exit("bad packet size");
|
||||
}
|
||||
|
||||
buf_setpos(ses.decryptreadbuf, PACKET_PAYLOAD_OFF);
|
||||
buf_setpos(ses.readbuf, PACKET_PAYLOAD_OFF);
|
||||
|
||||
#ifndef DISABLE_ZLIB
|
||||
if (is_compress_recv()) {
|
||||
/* decompress */
|
||||
ses.payload = buf_decompress(ses.decryptreadbuf, len);
|
||||
ses.payload = buf_decompress(ses.readbuf, len);
|
||||
} else
|
||||
#endif
|
||||
{
|
||||
/* copy payload */
|
||||
ses.payload = buf_new(len);
|
||||
memcpy(ses.payload->data, buf_getptr(ses.decryptreadbuf, len), len);
|
||||
memcpy(ses.payload->data, buf_getptr(ses.readbuf, len), len);
|
||||
buf_incrlen(ses.payload, len);
|
||||
}
|
||||
|
||||
buf_free(ses.decryptreadbuf);
|
||||
ses.decryptreadbuf = NULL;
|
||||
buf_free(ses.readbuf);
|
||||
ses.readbuf = NULL;
|
||||
buf_setpos(ses.payload, 0);
|
||||
|
||||
ses.recvseq++;
|
||||
@ -296,49 +292,22 @@ void decrypt_packet() {
|
||||
TRACE(("leave decrypt_packet"))
|
||||
}
|
||||
|
||||
/* Checks the mac in hashbuf, for the data in readbuf.
|
||||
/* Checks the mac at the end of a decrypted readbuf.
|
||||
* Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
|
||||
static int checkmac(buffer* macbuf, buffer* sourcebuf) {
|
||||
static int checkmac() {
|
||||
|
||||
unsigned int macsize;
|
||||
hmac_state hmac;
|
||||
unsigned char tempbuf[MAX_MAC_LEN];
|
||||
unsigned long bufsize;
|
||||
unsigned int len;
|
||||
|
||||
macsize = ses.keys->recv_algo_mac->hashsize;
|
||||
if (macsize == 0) {
|
||||
return DROPBEAR_SUCCESS;
|
||||
}
|
||||
|
||||
/* calculate the mac */
|
||||
if (hmac_init(&hmac,
|
||||
find_hash(ses.keys->recv_algo_mac->hashdesc->name),
|
||||
ses.keys->recvmackey,
|
||||
ses.keys->recv_algo_mac->keysize)
|
||||
!= CRYPT_OK) {
|
||||
dropbear_exit("HMAC error");
|
||||
}
|
||||
unsigned char mac_bytes[MAX_MAC_LEN];
|
||||
unsigned int mac_size, contents_len;
|
||||
|
||||
/* sequence number */
|
||||
STORE32H(ses.recvseq, tempbuf);
|
||||
if (hmac_process(&hmac, tempbuf, 4) != CRYPT_OK) {
|
||||
dropbear_exit("HMAC error");
|
||||
}
|
||||
mac_size = ses.keys->trans.algo_mac->hashsize;
|
||||
contents_len = ses.readbuf->len - mac_size;
|
||||
|
||||
buf_setpos(sourcebuf, 0);
|
||||
len = sourcebuf->len;
|
||||
if (hmac_process(&hmac, buf_getptr(sourcebuf, len), len) != CRYPT_OK) {
|
||||
dropbear_exit("HMAC error");
|
||||
}
|
||||
|
||||
bufsize = sizeof(tempbuf);
|
||||
if (hmac_done(&hmac, tempbuf, &bufsize) != CRYPT_OK) {
|
||||
dropbear_exit("HMAC error");
|
||||
}
|
||||
buf_setpos(ses.readbuf, 0);
|
||||
make_mac(ses.recvseq, &ses.keys->recv, ses.readbuf, contents_len, mac_bytes);
|
||||
|
||||
/* compare the hash */
|
||||
if (memcmp(tempbuf, buf_getptr(macbuf, macsize), macsize) != 0) {
|
||||
buf_setpos(ses.readbuf, contents_len);
|
||||
if (memcmp(mac_bytes, buf_getptr(ses.readbuf, mac_size), mac_size) != 0) {
|
||||
return DROPBEAR_FAILURE;
|
||||
} else {
|
||||
return DROPBEAR_SUCCESS;
|
||||
@ -353,7 +322,7 @@ static buffer* buf_decompress(buffer* buf, unsigned int len) {
|
||||
buffer * ret;
|
||||
z_streamp zstream;
|
||||
|
||||
zstream = ses.keys->recv_zstream;
|
||||
zstream = ses.keys->recv.zstream;
|
||||
ret = buf_new(len);
|
||||
|
||||
zstream->avail_in = len;
|
||||
@ -468,8 +437,8 @@ void encrypt_packet() {
|
||||
return;
|
||||
}
|
||||
|
||||
blocksize = ses.keys->trans_algo_crypt->blocksize;
|
||||
mac_size = ses.keys->trans_algo_mac->hashsize;
|
||||
blocksize = ses.keys->trans.algo_crypt->blocksize;
|
||||
mac_size = ses.keys->trans.algo_mac->hashsize;
|
||||
|
||||
/* Encrypted packet len is payload+5, then worst case is if we are 3 away
|
||||
* from a blocksize multiple. In which case we need to pad to the
|
||||
@ -526,17 +495,17 @@ void encrypt_packet() {
|
||||
buf_incrlen(writebuf, padlen);
|
||||
genrandom(buf_getptr(writebuf, padlen), padlen);
|
||||
|
||||
make_mac(writebuf, mac_bytes);
|
||||
make_mac(ses.transseq, &ses.keys->trans, writebuf, writebuf->len, mac_bytes);
|
||||
|
||||
/* do the actual encryption, in-place */
|
||||
buf_setpos(writebuf, 0);
|
||||
/* encrypt it in-place*/
|
||||
len = writebuf->len;
|
||||
if (ses.keys->trans_crypt_mode->encrypt(
|
||||
if (ses.keys->trans.crypt_mode->encrypt(
|
||||
buf_getptr(writebuf, len),
|
||||
buf_getwriteptr(writebuf, len),
|
||||
len,
|
||||
&ses.keys->trans_cipher_state) != CRYPT_OK) {
|
||||
&ses.keys->trans.cipher_state) != CRYPT_OK) {
|
||||
dropbear_exit("error encrypting");
|
||||
}
|
||||
buf_incrpos(writebuf, len);
|
||||
@ -557,35 +526,36 @@ void encrypt_packet() {
|
||||
|
||||
|
||||
/* Create the packet mac, and append H(seqno|clearbuf) to the output */
|
||||
/* output_mac must have ses.keys->trans_algo_mac->hashsize bytes. */
|
||||
static void make_mac(buffer * clearwritebuf, unsigned char *output_mac) {
|
||||
/* output_mac must have ses.keys->trans.algo_mac->hashsize bytes. */
|
||||
static void make_mac(unsigned int seqno, const struct key_context_directional * key_state,
|
||||
buffer * clear_buf, unsigned int clear_len,
|
||||
unsigned char *output_mac) {
|
||||
unsigned char seqbuf[4];
|
||||
unsigned long bufsize;
|
||||
hmac_state hmac;
|
||||
|
||||
TRACE(("enter writemac"))
|
||||
|
||||
if (ses.keys->trans_algo_mac->hashsize > 0) {
|
||||
if (key_state->algo_mac->hashsize > 0) {
|
||||
/* calculate the mac */
|
||||
if (hmac_init(&hmac,
|
||||
find_hash(ses.keys->trans_algo_mac->hashdesc->name),
|
||||
ses.keys->transmackey,
|
||||
ses.keys->trans_algo_mac->keysize) != CRYPT_OK) {
|
||||
key_state->hash_index,
|
||||
key_state->mackey,
|
||||
key_state->algo_mac->keysize) != CRYPT_OK) {
|
||||
dropbear_exit("HMAC error");
|
||||
}
|
||||
|
||||
/* sequence number */
|
||||
STORE32H(ses.transseq, seqbuf);
|
||||
STORE32H(seqno, seqbuf);
|
||||
if (hmac_process(&hmac, seqbuf, 4) != CRYPT_OK) {
|
||||
dropbear_exit("HMAC error");
|
||||
}
|
||||
|
||||
/* the actual contents */
|
||||
buf_setpos(clearwritebuf, 0);
|
||||
buf_setpos(clear_buf, 0);
|
||||
if (hmac_process(&hmac,
|
||||
buf_getptr(clearwritebuf,
|
||||
clearwritebuf->len),
|
||||
clearwritebuf->len) != CRYPT_OK) {
|
||||
buf_getptr(clear_buf, clear_len),
|
||||
clear_len) != CRYPT_OK) {
|
||||
dropbear_exit("HMAC error");
|
||||
}
|
||||
|
||||
@ -609,29 +579,29 @@ static void buf_compress(buffer * dest, buffer * src, unsigned int len) {
|
||||
|
||||
while (1) {
|
||||
|
||||
ses.keys->trans_zstream->avail_in = endpos - src->pos;
|
||||
ses.keys->trans_zstream->next_in =
|
||||
buf_getptr(src, ses.keys->trans_zstream->avail_in);
|
||||
ses.keys->trans.zstream->avail_in = endpos - src->pos;
|
||||
ses.keys->trans.zstream->next_in =
|
||||
buf_getptr(src, ses.keys->trans.zstream->avail_in);
|
||||
|
||||
ses.keys->trans_zstream->avail_out = dest->size - dest->pos;
|
||||
ses.keys->trans_zstream->next_out =
|
||||
buf_getwriteptr(dest, ses.keys->trans_zstream->avail_out);
|
||||
ses.keys->trans.zstream->avail_out = dest->size - dest->pos;
|
||||
ses.keys->trans.zstream->next_out =
|
||||
buf_getwriteptr(dest, ses.keys->trans.zstream->avail_out);
|
||||
|
||||
result = deflate(ses.keys->trans_zstream, Z_SYNC_FLUSH);
|
||||
result = deflate(ses.keys->trans.zstream, Z_SYNC_FLUSH);
|
||||
|
||||
buf_setpos(src, endpos - ses.keys->trans_zstream->avail_in);
|
||||
buf_setlen(dest, dest->size - ses.keys->trans_zstream->avail_out);
|
||||
buf_setpos(src, endpos - ses.keys->trans.zstream->avail_in);
|
||||
buf_setlen(dest, dest->size - ses.keys->trans.zstream->avail_out);
|
||||
buf_setpos(dest, dest->len);
|
||||
|
||||
if (result != Z_OK) {
|
||||
dropbear_exit("zlib error");
|
||||
}
|
||||
|
||||
if (ses.keys->trans_zstream->avail_in == 0) {
|
||||
if (ses.keys->trans.zstream->avail_in == 0) {
|
||||
break;
|
||||
}
|
||||
|
||||
dropbear_assert(ses.keys->trans_zstream->avail_out == 0);
|
||||
dropbear_assert(ses.keys->trans.zstream->avail_out == 0);
|
||||
|
||||
/* the buffer has been filled, we must extend. This only happens in
|
||||
* unusual circumstances where the data grows in size after deflate(),
|
||||
|
||||
2
packet.h
2
packet.h
@ -44,6 +44,6 @@ typedef struct PacketType {
|
||||
#define PACKET_PADDING_OFF 4
|
||||
#define PACKET_PAYLOAD_OFF 5
|
||||
|
||||
#define INIT_READBUF 200
|
||||
#define INIT_READBUF 128
|
||||
|
||||
#endif /* _PACKET_H_ */
|
||||
|
||||
51
session.h
51
session.h
@ -60,42 +60,36 @@ void cli_session(int sock_in, int sock_out, char *remotehost);
|
||||
void cli_session_cleanup();
|
||||
void cleantext(unsigned char* dirtytext);
|
||||
|
||||
struct key_context {
|
||||
|
||||
const struct dropbear_cipher *recv_algo_crypt; /* NULL for none */
|
||||
const struct dropbear_cipher *trans_algo_crypt; /* NULL for none */
|
||||
const struct dropbear_cipher_mode *recv_crypt_mode;
|
||||
const struct dropbear_cipher_mode *trans_crypt_mode;
|
||||
const struct dropbear_hash *recv_algo_mac; /* NULL for none */
|
||||
const struct dropbear_hash *trans_algo_mac; /* NULL for none */
|
||||
char algo_kex;
|
||||
char algo_hostkey;
|
||||
|
||||
char recv_algo_comp; /* compression */
|
||||
char trans_algo_comp;
|
||||
int allow_compress; /* whether compression has started (useful in
|
||||
zlib@openssh.com delayed compression case) */
|
||||
/* crypto parameters that are stored individually for transmit and receive */
|
||||
struct key_context_directional {
|
||||
const struct dropbear_cipher *algo_crypt; /* NULL for none */
|
||||
const struct dropbear_cipher_mode *crypt_mode;
|
||||
const struct dropbear_hash *algo_mac; /* NULL for none */
|
||||
int hash_index; /* lookup for libtomcrypt */
|
||||
char algo_comp; /* compression */
|
||||
#ifndef DISABLE_ZLIB
|
||||
z_streamp recv_zstream;
|
||||
z_streamp trans_zstream;
|
||||
z_streamp zstream;
|
||||
#endif
|
||||
|
||||
/* actual keys */
|
||||
union {
|
||||
symmetric_CBC cbc;
|
||||
#ifdef DROPBEAR_ENABLE_CTR_MODE
|
||||
symmetric_CTR ctr;
|
||||
#endif
|
||||
} recv_cipher_state;
|
||||
union {
|
||||
symmetric_CBC cbc;
|
||||
#ifdef DROPBEAR_ENABLE_CTR_MODE
|
||||
symmetric_CTR ctr;
|
||||
#endif
|
||||
} trans_cipher_state;
|
||||
unsigned char recvmackey[MAX_MAC_KEY];
|
||||
unsigned char transmackey[MAX_MAC_KEY];
|
||||
} cipher_state;
|
||||
unsigned char mackey[MAX_MAC_KEY];
|
||||
};
|
||||
|
||||
struct key_context {
|
||||
|
||||
struct key_context_directional recv;
|
||||
struct key_context_directional trans;
|
||||
|
||||
char algo_kex;
|
||||
char algo_hostkey;
|
||||
|
||||
int allow_compress; /* whether compression has started (useful in
|
||||
zlib@openssh.com delayed compression case) */
|
||||
};
|
||||
|
||||
struct packetlist;
|
||||
@ -128,8 +122,7 @@ struct sshsession {
|
||||
throughout the code, as handlers fill out this
|
||||
buffer with the packet to send. */
|
||||
struct Queue writequeue; /* A queue of encrypted packets to send */
|
||||
buffer *readbuf; /* Encrypted */
|
||||
buffer *decryptreadbuf; /* Post-decryption */
|
||||
buffer *readbuf; /* From the wire, decrypted in-place */
|
||||
buffer *payload; /* Post-decompression, the actual SSH packet */
|
||||
unsigned int transseq, recvseq; /* Sequence IDs */
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user