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/*
20140110
Jan Mojzis
Public domain.
*/
#include "buf.h"
#include "ssh.h"
#include "sshcrypto.h"
#include "packetparser.h"
#include "bug.h"
#include "packet.h"
int packet_kex_send(void) {
struct buf *b = &packet.kexsend;
/* send server kex_init */
buf_purge(b);
buf_putnum8(b, SSH_MSG_KEXINIT); /* SSH_MSG_KEXINIT */
buf_putrandombytes(b, 16); /* cookie */
sshcrypto_kex_put(b); /* kex algorithms */
sshcrypto_key_put(b); /* server host key algorithms */
sshcrypto_cipher_put(b); /* encryption algorithms client to server */
sshcrypto_cipher_put(b); /* encryption algorithms server to client */
sshcrypto_cipher_macput(b); /* mac algorithms client to server */
sshcrypto_cipher_macput(b); /* mac algorithms server to client */
buf_putstring(b, "none"); /* compress algorithms client to server */
buf_putstring(b, "none"); /* compress algorithms server to client */
buf_putstring(b, ""); /* languages client to server */
buf_putstring(b, ""); /* languages server to client */
buf_putnum8(b, 0); /* kex first packet follows */
buf_putnum32(b, 0); /* reserved */
packet_put(b);
return packet_sendall();
}
int packet_kex_receive(void) {
struct buf *b = &packet.kexrecv;
long long pos = 0;
crypto_uint8 ch;
crypto_uint32 len;
if (!packet_getall(b, SSH_MSG_KEXINIT)) return 0;
/* parse packet */
pos = packetparser_uint8(b->buf, b->len, pos, &ch); /* SSH_MSG_KEXINIT */
if (ch != SSH_MSG_KEXINIT) bug_proto();
pos = packetparser_skip(b->buf, b->len, pos, 16); /* cookie */
pos = packetparser_uint32(b->buf, b->len, pos, &len); /* kex algorithms */
pos = packetparser_skip(b->buf, b->len, pos, len);
if (!sshcrypto_kex_select(b->buf + pos - len, len, &packet.kex_guess))
return 0;
pos = packetparser_uint32(b->buf, b->len, pos,
&len); /* server host key algorithms */
pos = packetparser_skip(b->buf, b->len, pos, len);
if (!sshcrypto_key_select(b->buf + pos - len, len)) return 0;
pos = packetparser_uint32(
b->buf, b->len, pos, &len); /* encryption algorithms client to server */
pos = packetparser_skip(b->buf, b->len, pos, len);
if (!sshcrypto_cipher_select(b->buf + pos - len, len)) return 0;
pos = packetparser_uint32(
b->buf, b->len, pos, &len); /* encryption algorithms server to client */
pos = packetparser_skip(b->buf, b->len, pos, len);
/* XXX assuming same as encryption algorithms client to server */
pos = packetparser_uint32(b->buf, b->len, pos,
&len); /* mac algorithms client to server */
pos = packetparser_skip(b->buf, b->len, pos, len);
if (!sshcrypto_cipher_macselect(b->buf + pos - len, len)) return 0;
pos = packetparser_uint32(b->buf, b->len, pos,
&len); /* mac algorithms server to client */
pos = packetparser_skip(b->buf, b->len, pos, len);
pos = packetparser_uint32(b->buf, b->len, pos,
&len); /* compress algorithms client to server */
pos = packetparser_skip(b->buf, b->len, pos, len);
pos = packetparser_uint32(b->buf, b->len, pos,
&len); /* compress algorithms server to client */
pos = packetparser_skip(b->buf, b->len, pos, len);
pos = packetparser_uint32(b->buf, b->len, pos,
&len); /* languages client to server */
pos = packetparser_skip(b->buf, b->len, pos, len);
pos = packetparser_uint32(b->buf, b->len, pos,
&len); /* languages server to client */
pos = packetparser_skip(b->buf, b->len, pos, len);
pos = packetparser_uint8(b->buf, b->len, pos,
&ch); /* kex first packet follows */
packet.kex_packet_follows = ch;
pos = packetparser_uint32(b->buf, b->len, pos, &len); /* reserved */
pos = packetparser_end(b->buf, b->len, pos);
return 1;
}
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