diff options
Diffstat (limited to 'packet.c')
| -rw-r--r-- | packet.c | 145 |
1 files changed, 102 insertions, 43 deletions
@@ -215,7 +215,7 @@ static int read_packet_init() { unsigned int maxlen; int slen; - unsigned int len; + unsigned int len, plen; unsigned int blocksize; unsigned int macsize; @@ -254,21 +254,35 @@ static int read_packet_init() { /* now we have the first block, need to get packet length, so we decrypt * the first block (only need first 4 bytes) */ buf_setpos(ses.readbuf, 0); - if (ses.keys->recv.crypt_mode->decrypt(buf_getptr(ses.readbuf, blocksize), - buf_getwriteptr(ses.readbuf, blocksize), - blocksize, - &ses.keys->recv.cipher_state) != CRYPT_OK) { - dropbear_exit("Error decrypting"); +#if DROPBEAR_AEAD_MODE + if (ses.keys->recv.crypt_mode->aead_crypt) { + if (ses.keys->recv.crypt_mode->aead_getlength(ses.recvseq, + buf_getptr(ses.readbuf, blocksize), &plen, + blocksize, + &ses.keys->recv.cipher_state) != CRYPT_OK) { + dropbear_exit("Error decrypting"); + } + len = plen + 4 + macsize; + } else +#endif + { + if (ses.keys->recv.crypt_mode->decrypt(buf_getptr(ses.readbuf, blocksize), + buf_getwriteptr(ses.readbuf, blocksize), + blocksize, + &ses.keys->recv.cipher_state) != CRYPT_OK) { + dropbear_exit("Error decrypting"); + } + plen = buf_getint(ses.readbuf) + 4; + len = plen + macsize; } - len = buf_getint(ses.readbuf) + 4 + macsize; TRACE2(("packet size is %u, block %u mac %u", len, blocksize, macsize)) /* check packet length */ if ((len > RECV_MAX_PACKET_LEN) || - (len < MIN_PACKET_LEN + macsize) || - ((len - macsize) % blocksize != 0)) { + (plen < blocksize) || + (plen % blocksize != 0)) { dropbear_exit("Integrity error (bad packet size %u)", len); } @@ -294,23 +308,42 @@ void decrypt_packet() { ses.kexstate.datarecv += ses.readbuf->len; - /* we've already decrypted the first blocksize in read_packet_init */ - buf_setpos(ses.readbuf, blocksize); - - /* decrypt it in-place */ - len = ses.readbuf->len - macsize - ses.readbuf->pos; - if (ses.keys->recv.crypt_mode->decrypt( - buf_getptr(ses.readbuf, len), - buf_getwriteptr(ses.readbuf, len), - len, - &ses.keys->recv.cipher_state) != CRYPT_OK) { - dropbear_exit("Error decrypting"); - } - buf_incrpos(ses.readbuf, len); +#if DROPBEAR_AEAD_MODE + if (ses.keys->recv.crypt_mode->aead_crypt) { + /* first blocksize is not decrypted yet */ + buf_setpos(ses.readbuf, 0); + + /* decrypt it in-place */ + len = ses.readbuf->len - macsize - ses.readbuf->pos; + if (ses.keys->recv.crypt_mode->aead_crypt(ses.recvseq, + buf_getptr(ses.readbuf, len + macsize), + buf_getwriteptr(ses.readbuf, len), + len, macsize, + &ses.keys->recv.cipher_state, LTC_DECRYPT) != CRYPT_OK) { + dropbear_exit("Error decrypting"); + } + buf_incrpos(ses.readbuf, len); + } else +#endif + { + /* we've already decrypted the first blocksize in read_packet_init */ + buf_setpos(ses.readbuf, blocksize); + + /* decrypt it in-place */ + len = ses.readbuf->len - macsize - ses.readbuf->pos; + if (ses.keys->recv.crypt_mode->decrypt( + buf_getptr(ses.readbuf, len), + buf_getwriteptr(ses.readbuf, len), + len, + &ses.keys->recv.cipher_state) != CRYPT_OK) { + dropbear_exit("Error decrypting"); + } + buf_incrpos(ses.readbuf, len); - /* check the hmac */ - if (checkmac() != DROPBEAR_SUCCESS) { - dropbear_exit("Integrity error"); + /* check the hmac */ + if (checkmac() != DROPBEAR_SUCCESS) { + dropbear_exit("Integrity error"); + } } /* get padding length */ @@ -557,9 +590,16 @@ void encrypt_packet() { buf_setpos(ses.writepayload, 0); buf_setlen(ses.writepayload, 0); - /* length of padding - packet length must be a multiple of blocksize, - * with a minimum of 4 bytes of padding */ - padlen = blocksize - (writebuf->len) % blocksize; + /* length of padding - packet length excluding the packetlength uint32 + * field in aead mode must be a multiple of blocksize, with a minimum of + * 4 bytes of padding */ + len = writebuf->len; +#if DROPBEAR_AEAD_MODE + if (ses.keys->trans.crypt_mode->aead_crypt) { + len -= 4; + } +#endif + padlen = blocksize - len % blocksize; if (padlen < 4) { padlen += blocksize; } @@ -579,23 +619,42 @@ void encrypt_packet() { buf_incrlen(writebuf, padlen); genrandom(buf_getptr(writebuf, padlen), padlen); - make_mac(ses.transseq, &ses.keys->trans, writebuf, writebuf->len, mac_bytes); +#if DROPBEAR_AEAD_MODE + if (ses.keys->trans.crypt_mode->aead_crypt) { + /* do the actual encryption, in-place */ + buf_setpos(writebuf, 0); + /* encrypt it in-place*/ + len = writebuf->len; + buf_incrlen(writebuf, mac_size); + if (ses.keys->trans.crypt_mode->aead_crypt(ses.transseq, + buf_getptr(writebuf, len), + buf_getwriteptr(writebuf, len + mac_size), + len, mac_size, + &ses.keys->trans.cipher_state, LTC_ENCRYPT) != CRYPT_OK) { + dropbear_exit("Error encrypting"); + } + buf_incrpos(writebuf, len + mac_size); + } else +#endif + { + 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( + buf_getptr(writebuf, len), + buf_getwriteptr(writebuf, len), + len, + &ses.keys->trans.cipher_state) != CRYPT_OK) { + dropbear_exit("Error encrypting"); + } + buf_incrpos(writebuf, len); - /* do the actual encryption, in-place */ - buf_setpos(writebuf, 0); - /* encrypt it in-place*/ - len = writebuf->len; - if (ses.keys->trans.crypt_mode->encrypt( - buf_getptr(writebuf, len), - buf_getwriteptr(writebuf, len), - len, - &ses.keys->trans.cipher_state) != CRYPT_OK) { - dropbear_exit("Error encrypting"); + /* stick the MAC on it */ + buf_putbytes(writebuf, mac_bytes, mac_size); } - buf_incrpos(writebuf, len); - - /* stick the MAC on it */ - buf_putbytes(writebuf, mac_bytes, mac_size); /* Update counts */ ses.kexstate.datatrans += writebuf->len; |