int ssh_get_kex(SSH_SESSION *session,int server_kex ){
STRING *str;
char *strings[10];
int i;
if(packet_wait(session,SSH2_MSG_KEXINIT,1))
return -1;
if(buffer_get_data(session->in_buffer,session->server_kex.cookie,16)!=16){
ssh_set_error(session,SSH_FATAL,"get_kex(): no cookie in packet");
return -1;
}
hashbufin_add_cookie(session,session->server_kex.cookie);
memset(strings,0,sizeof(char *)*10);
for(i=0;i<10;++i){
str=buffer_get_ssh_string(session->in_buffer);
if(!str)
break;
if(str){
buffer_add_ssh_string(session->in_hashbuf,str);
strings[i]=string_to_char(str);
free(str);
} else
strings[i]=NULL;
}
/* copy the server kex info into an array of strings */
if(server_kex){
session->client_kex.methods=malloc( 10 * sizeof(char **));
for(i=0;i<10;++i)
session->client_kex.methods[i]=strings[i];
} else { // client
session->server_kex.methods=malloc( 10 * sizeof(char **));
for(i=0;i<10;++i)
session->server_kex.methods[i]=strings[i];
}
return 0;
}
int ssh_service_request(SSH_SESSION *session,char *service){
STRING *service_s;
packet_clear_out(session);
buffer_add_u8(session->out_buffer,SSH2_MSG_SERVICE_REQUEST);
service_s=string_from_char(service);
buffer_add_ssh_string(session->out_buffer,service_s);
free(service_s);
packet_send(session);
ssh_say(3,"Sent SSH_MSG_SERVICE_REQUEST (service %s)\n",service);
if(packet_wait(session,SSH2_MSG_SERVICE_ACCEPT,1)){
ssh_set_error(session,SSH_FATAL,"did not receive SERVICE_ACCEPT");
return -1;
}
ssh_say(3,"Received SSH_MSG_SERVICE_ACCEPT (service %s)\n",service);
return 0;
}
/**
* @brief Get the exit status of the channel (error code from the executed
* instruction).
*
* @param channel The channel to get the status from.
*
* @return -1 if no exit status has been returned or eof not sent,
* the exit status othewise.
*/
int channel_get_exit_status(CHANNEL *channel) {
if (channel->local_eof == 0) {
return -1;
}
while (channel->remote_eof == 0 || channel->exit_status == -1) {
/* Parse every incoming packet */
if (packet_wait(channel->session, 0, 0) != SSH_OK) {
return -1;
}
if (channel->open == 0) {
return -1;
}
}
return channel->exit_status;
}
int channel_change_pty_size1(ssh_channel channel, int cols, int rows) {
ssh_session session = channel->session;
if (buffer_add_u8(session->out_buffer, SSH_CMSG_WINDOW_SIZE) < 0 ||
buffer_add_u32(session->out_buffer, ntohl(rows)) < 0 ||
buffer_add_u32(session->out_buffer, ntohl(cols)) < 0 ||
buffer_add_u32(session->out_buffer, 0) < 0 ||
buffer_add_u32(session->out_buffer, 0) < 0) {
return -1;
}
if (packet_send(session)) {
return -1;
}
ssh_log(session, SSH_LOG_RARE, "Change pty size send");
if (packet_wait(session, SSH_SMSG_SUCCESS, 1) != SSH_OK) {
return -1;
}
switch (session->in_packet.type) {
case SSH_SMSG_SUCCESS:
ssh_log(session, SSH_LOG_RARE, "pty size changed");
return 0;
case SSH_SMSG_FAILURE:
ssh_log(session, SSH_LOG_RARE, "pty size change denied");
ssh_set_error(session, SSH_REQUEST_DENIED, "pty size change denied");
return -1;
}
ssh_set_error(session, SSH_FATAL, "Received unexpected packet type %d",
session->in_packet.type);
return -1;
}
int ssh_get_kex1(SSH_SESSION *session) {
STRING *server_exp = NULL;
STRING *server_mod = NULL;
STRING *host_exp = NULL;
STRING *host_mod = NULL;
STRING *serverkey = NULL;
STRING *hostkey = NULL;
STRING *enc_session = NULL;
PUBLIC_KEY *srv = NULL;
PUBLIC_KEY *host = NULL;
u32 server_bits;
u32 host_bits;
u32 protocol_flags;
u32 supported_ciphers_mask;
u32 supported_authentications_mask;
u16 bits;
int rc = -1;
int ko;
enter_function();
ssh_log(session, SSH_LOG_PROTOCOL, "Waiting for a SSH_SMSG_PUBLIC_KEY");
if (packet_wait(session, SSH_SMSG_PUBLIC_KEY, 1) != SSH_OK) {
leave_function();
return -1;
}
ssh_log(session, SSH_LOG_PROTOCOL, "Got a SSH_SMSG_PUBLIC_KEY");
if (buffer_get_data(session->in_buffer, session->server_kex.cookie, 8) != 8) {
ssh_set_error(session, SSH_FATAL, "Can't get cookie in buffer");
leave_function();
return -1;
}
buffer_get_u32(session->in_buffer, &server_bits);
server_exp = buffer_get_mpint(session->in_buffer);
if (server_exp == NULL) {
goto error;
}
server_mod = buffer_get_mpint(session->in_buffer);
if (server_mod == NULL) {
goto error;
}
buffer_get_u32(session->in_buffer, &host_bits);
host_exp = buffer_get_mpint(session->in_buffer);
if (host_exp == NULL) {
goto error;
}
host_mod = buffer_get_mpint(session->in_buffer);
if (host_mod == NULL) {
goto error;
}
buffer_get_u32(session->in_buffer, &protocol_flags);
buffer_get_u32(session->in_buffer, &supported_ciphers_mask);
ko = buffer_get_u32(session->in_buffer, &supported_authentications_mask);
if ((ko != sizeof(u32)) || !host_mod || !host_exp
|| !server_mod || !server_exp) {
ssh_log(session, SSH_LOG_RARE, "Invalid SSH_SMSG_PUBLIC_KEY packet");
ssh_set_error(session, SSH_FATAL, "Invalid SSH_SMSG_PUBLIC_KEY packet");
goto error;
}
server_bits = ntohl(server_bits);
host_bits = ntohl(host_bits);
protocol_flags = ntohl(protocol_flags);
supported_ciphers_mask = ntohl(supported_ciphers_mask);
supported_authentications_mask = ntohl(supported_authentications_mask);
ssh_log(session, SSH_LOG_PROTOCOL,
"Server bits: %d; Host bits: %d; Protocol flags: %.8lx; "
"Cipher mask: %.8lx; Auth mask: %.8lx",
server_bits,
host_bits,
(unsigned long int) protocol_flags,
(unsigned long int) supported_ciphers_mask,
(unsigned long int) supported_authentications_mask);
serverkey = make_rsa1_string(server_exp, server_mod);
if (serverkey == NULL) {
goto error;
}
hostkey = make_rsa1_string(host_exp,host_mod);
if (serverkey == NULL) {
goto error;
}
if (build_session_id1(session, server_mod, host_mod) < 0) {
goto error;
}
srv = publickey_from_string(session, serverkey);
if (srv == NULL) {
goto error;
}
host = publickey_from_string(session, hostkey);
if (host == NULL) {
goto error;
}
session->next_crypto->server_pubkey = string_copy(hostkey);
if (session->next_crypto->server_pubkey == NULL) {
goto error;
}
session->next_crypto->server_pubkey_type = "ssh-rsa1";
/* now, we must choose an encryption algo */
/* hardcode 3des */
if (!(supported_ciphers_mask & (1 << SSH_CIPHER_3DES))) {
ssh_set_error(session, SSH_FATAL, "Remote server doesn't accept 3DES");
goto error;
}
ssh_log(session, SSH_LOG_PROTOCOL, "Sending SSH_CMSG_SESSION_KEY");
if (buffer_add_u8(session->out_buffer, SSH_CMSG_SESSION_KEY) < 0) {
goto error;
}
if (buffer_add_u8(session->out_buffer, SSH_CIPHER_3DES) < 0) {
goto error;
}
if (buffer_add_data(session->out_buffer, session->server_kex.cookie, 8) < 0) {
goto error;
}
enc_session = encrypt_session_key(session, srv, host, server_bits, host_bits);
if (enc_session == NULL) {
goto error;
}
bits = string_len(enc_session) * 8 - 7;
ssh_log(session, SSH_LOG_PROTOCOL, "%d bits, %zu bytes encrypted session",
bits, string_len(enc_session));
bits = htons(bits);
/* the encrypted mpint */
if (buffer_add_data(session->out_buffer, &bits, sizeof(u16)) < 0) {
goto error;
}
if (buffer_add_data(session->out_buffer, enc_session->string,
string_len(enc_session)) < 0) {
goto error;
}
/* the protocol flags */
if (buffer_add_u32(session->out_buffer, 0) < 0) {
goto error;
}
if (packet_send(session) != SSH_OK) {
goto error;
}
/* we can set encryption */
if (crypt_set_algorithms(session)) {
goto error;
}
session->current_crypto = session->next_crypto;
session->next_crypto = NULL;
ssh_log(session, SSH_LOG_PROTOCOL, "Waiting for a SSH_SMSG_SUCCESS");
if (packet_wait(session,SSH_SMSG_SUCCESS,1) != SSH_OK) {
char buffer[1024] = {0};
snprintf(buffer, sizeof(buffer),
"Key exchange failed: %s", ssh_get_error(session));
ssh_set_error(session, SSH_FATAL, "%s",buffer);
goto error;
}
ssh_log(session, SSH_LOG_PROTOCOL, "received SSH_SMSG_SUCCESS\n");
rc = 0;
error:
string_free(host_mod);
string_free(host_exp);
string_free(server_mod);
string_free(server_exp);
string_free(serverkey);
string_free(hostkey);
publickey_free(srv);
publickey_free(host);
leave_function();
return rc;
}
int ssh_get_kex(SSH_SESSION *session, int server_kex) {
STRING *str = NULL;
char *strings[10];
int i;
enter_function();
if (packet_wait(session, SSH2_MSG_KEXINIT, 1) != SSH_OK) {
leave_function();
return -1;
}
if (buffer_get_data(session->in_buffer,session->server_kex.cookie,16) != 16) {
ssh_set_error(session, SSH_FATAL, "get_kex(): no cookie in packet");
leave_function();
return -1;
}
if (hashbufin_add_cookie(session, session->server_kex.cookie) < 0) {
ssh_set_error(session, SSH_FATAL, "get_kex(): adding cookie failed");
leave_function();
return -1;
}
memset(strings, 0, sizeof(char *) * 10);
for (i = 0; i < 10; i++) {
str = buffer_get_ssh_string(session->in_buffer);
if (str == NULL) {
break;
}
if (buffer_add_ssh_string(session->in_hashbuf, str) < 0) {
goto error;
}
strings[i] = string_to_char(str);
if (strings[i] == NULL) {
goto error;
}
string_free(str);
str = NULL;
}
/* copy the server kex info into an array of strings */
if (server_kex) {
session->client_kex.methods = malloc(10 * sizeof(char **));
if (session->client_kex.methods == NULL) {
leave_function();
return -1;
}
for (i = 0; i < 10; i++) {
session->client_kex.methods[i] = strings[i];
}
} else { /* client */
session->server_kex.methods = malloc(10 * sizeof(char **));
if (session->server_kex.methods == NULL) {
leave_function();
return -1;
}
for (i = 0; i < 10; i++) {
session->server_kex.methods[i] = strings[i];
}
}
leave_function();
return 0;
error:
string_free(str);
for (i = 0; i < 10; i++) {
SAFE_FREE(strings[i]);
}
leave_function();
return -1;
}
static int channel_request(CHANNEL *channel, const char *request,
BUFFER *buffer, int reply) {
SSH_SESSION *session = channel->session;
STRING *req = NULL;
int rc = SSH_ERROR;
enter_function();
req = string_from_char(request);
if (req == NULL) {
goto error;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_CHANNEL_REQUEST) < 0 ||
buffer_add_u32(session->out_buffer, htonl(channel->remote_channel)) < 0 ||
buffer_add_ssh_string(session->out_buffer, req) < 0 ||
buffer_add_u8(session->out_buffer, reply == 0 ? 0 : 1) < 0) {
goto error;
}
string_free(req);
if (buffer != NULL) {
if (buffer_add_data(session->out_buffer, buffer_get(buffer),
buffer_get_len(buffer)) < 0) {
goto error;
}
}
if (packet_send(session) != SSH_OK) {
leave_function();
return rc;
}
ssh_log(session, SSH_LOG_RARE,
"Sent a SSH_MSG_CHANNEL_REQUEST %s", request);
if (reply == 0) {
leave_function();
return SSH_OK;
}
rc = packet_wait(session, SSH2_MSG_CHANNEL_SUCCESS, 1);
if (rc) {
if (session->in_packet.type == SSH2_MSG_CHANNEL_FAILURE) {
ssh_log(session, SSH_LOG_PACKET,
"%s channel request failed", request);
ssh_set_error(session, SSH_REQUEST_DENIED,
"Channel request %s failed", request);
} else {
ssh_log(session, SSH_LOG_RARE,
"Received an unexpected %d message", session->in_packet.type);
}
} else {
ssh_log(session, SSH_LOG_RARE, "Received a SUCCESS");
}
leave_function();
return rc;
error:
buffer_free(session->out_buffer);
string_free(req);
leave_function();
return rc;
}
/**
* @brief Blocking write on channel.
*
* @param channel The channel to write to.
*
* @param data A pointer to the data to write.
*
* @param len The length of the buffer to write to.
*
* @return The number of bytes written, SSH_ERROR on error.
*
* @see channel_read()
*/
int channel_write(CHANNEL *channel, const void *data, u32 len) {
SSH_SESSION *session = channel->session;
int origlen = len;
int effectivelen;
enter_function();
if (channel->local_eof) {
ssh_set_error(session, SSH_REQUEST_DENIED,
"Can't write to channel %d:%d after EOF was sent",
channel->local_channel,
channel->remote_channel);
leave_function();
return -1;
}
if (channel->open == 0 || channel->delayed_close != 0) {
ssh_set_error(session, SSH_REQUEST_DENIED, "Remote channel is closed");
leave_function();
return -1;
}
#ifdef HAVE_SSH1
if (channel->version == 1) {
int rc = channel_write1(channel, data, len);
leave_function();
return rc;
}
#endif
while (len > 0) {
if (channel->remote_window < len) {
ssh_log(session, SSH_LOG_PROTOCOL,
"Remote window is %d bytes. going to write %d bytes",
channel->remote_window,
len);
ssh_log(session, SSH_LOG_PROTOCOL,
"Waiting for a growing window message...");
/* What happens when the channel window is zero? */
while(channel->remote_window == 0) {
/* parse every incoming packet */
packet_wait(channel->session, 0, 0);
}
effectivelen = len > channel->remote_window ? channel->remote_window : len;
} else {
effectivelen = len;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_CHANNEL_DATA) < 0 ||
buffer_add_u32(session->out_buffer,
htonl(channel->remote_channel)) < 0 ||
buffer_add_u32(session->out_buffer, htonl(effectivelen)) < 0 ||
buffer_add_data(session->out_buffer, data, effectivelen) < 0) {
goto error;
}
if (packet_send(session) != SSH_OK) {
leave_function();
return SSH_ERROR;
}
ssh_log(session, SSH_LOG_RARE,
"channel_write wrote %d bytes", effectivelen);
channel->remote_window -= effectivelen;
len -= effectivelen;
data += effectivelen;
}
leave_function();
return origlen;
error:
buffer_free(session->out_buffer);
leave_function();
return SSH_ERROR;
}
static int channel_open(CHANNEL *channel, const char *type_c, int window,
int maxpacket, BUFFER *payload) {
SSH_SESSION *session = channel->session;
STRING *type = NULL;
u32 tmp = 0;
enter_function();
channel->local_channel = ssh_channel_new_id(session);
channel->local_maxpacket = maxpacket;
channel->local_window = window;
ssh_log(session, SSH_LOG_RARE,
"Creating a channel %d with %d window and %d max packet",
channel->local_channel, window, maxpacket);
type = string_from_char(type_c);
if (type == NULL) {
leave_function();
return -1;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_CHANNEL_OPEN) < 0 ||
buffer_add_ssh_string(session->out_buffer,type) < 0 ||
buffer_add_u32(session->out_buffer, htonl(channel->local_channel)) < 0 ||
buffer_add_u32(session->out_buffer, htonl(channel->local_window)) < 0 ||
buffer_add_u32(session->out_buffer, htonl(channel->local_maxpacket)) < 0) {
string_free(type);
leave_function();
return -1;
}
string_free(type);
if (payload != NULL) {
if (buffer_add_buffer(session->out_buffer, payload) < 0) {
leave_function();
return -1;
}
}
if (packet_send(session) != SSH_OK) {
leave_function();
return -1;
}
ssh_log(session, SSH_LOG_RARE,
"Sent a SSH_MSG_CHANNEL_OPEN type %s for channel %d",
type_c, channel->local_channel);
if (packet_wait(session, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, 1) != SSH_OK) {
leave_function();
return -1;
}
switch(session->in_packet.type) {
case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
buffer_get_u32(session->in_buffer, &tmp);
if (channel->local_channel != ntohl(tmp)) {
ssh_set_error(session, SSH_FATAL,
"Server answered with sender channel number %lu instead of given %u",
(long unsigned int) ntohl(tmp),
channel->local_channel);
leave_function();
return -1;
}
buffer_get_u32(session->in_buffer, &tmp);
channel->remote_channel = ntohl(tmp);
buffer_get_u32(session->in_buffer, &tmp);
channel->remote_window = ntohl(tmp);
buffer_get_u32(session->in_buffer,&tmp);
channel->remote_maxpacket=ntohl(tmp);
ssh_log(session, SSH_LOG_PROTOCOL,
"Received a CHANNEL_OPEN_CONFIRMATION for channel %d:%d",
channel->local_channel,
channel->remote_channel);
ssh_log(session, SSH_LOG_PROTOCOL,
"Remote window : %lu, maxpacket : %lu",
(long unsigned int) channel->remote_window,
(long unsigned int) channel->remote_maxpacket);
channel->open = 1;
leave_function();
return 0;
case SSH2_MSG_CHANNEL_OPEN_FAILURE:
{
STRING *error_s;
char *error;
u32 code;
buffer_get_u32(session->in_buffer, &tmp);
buffer_get_u32(session->in_buffer, &code);
error_s = buffer_get_ssh_string(session->in_buffer);
error = string_to_char(error_s);
string_free(error_s);
if (error == NULL) {
leave_function();
return -1;
}
ssh_set_error(session, SSH_REQUEST_DENIED,
"Channel opening failure: channel %u error (%lu) %s",
channel->local_channel,
(long unsigned int) ntohl(code),
error);
SAFE_FREE(error);
leave_function();
return -1;
}
default:
ssh_set_error(session, SSH_FATAL,
"Received unknown packet %d\n", session->in_packet.type);
leave_function();
return -1;
}
leave_function();
return -1;
}
static int dh_handshake_server(SSH_SESSION *session) {
STRING *e;
STRING *f;
STRING *pubkey;
STRING *sign;
PUBLIC_KEY *pub;
PRIVATE_KEY *prv;
if (packet_wait(session, SSH2_MSG_KEXDH_INIT, 1) != SSH_OK) {
return -1;
}
e = buffer_get_ssh_string(session->in_buffer);
if (e == NULL) {
ssh_set_error(session, SSH_FATAL, "No e number in client request");
return -1;
}
if (dh_import_e(session, e) < 0) {
ssh_set_error(session, SSH_FATAL, "Cannot import e number");
string_free(e);
return -1;
}
string_free(e);
if (dh_generate_y(session) < 0) {
ssh_set_error(session, SSH_FATAL, "Could not create y number");
return -1;
}
if (dh_generate_f(session) < 0) {
ssh_set_error(session, SSH_FATAL, "Could not create f number");
return -1;
}
f = dh_get_f(session);
if (f == NULL) {
ssh_set_error(session, SSH_FATAL, "Could not get the f number");
return -1;
}
switch(session->hostkeys){
case TYPE_DSS:
prv = session->dsa_key;
break;
case TYPE_RSA:
prv = session->rsa_key;
break;
default:
prv = NULL;
}
pub = publickey_from_privatekey(prv);
if (pub == NULL) {
ssh_set_error(session, SSH_FATAL,
"Could not get the public key from the private key");
string_free(f);
return -1;
}
pubkey = publickey_to_string(pub);
publickey_free(pub);
if (pubkey == NULL) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
string_free(f);
return -1;
}
dh_import_pubkey(session, pubkey);
if (dh_build_k(session) < 0) {
ssh_set_error(session, SSH_FATAL, "Could not import the public key");
string_free(f);
return -1;
}
if (make_sessionid(session) != SSH_OK) {
ssh_set_error(session, SSH_FATAL, "Could not create a session id");
string_free(f);
return -1;
}
sign = ssh_sign_session_id(session, prv);
if (sign == NULL) {
ssh_set_error(session, SSH_FATAL, "Could not sign the session id");
string_free(f);
return -1;
}
/* Free private keys as they should not be readable after this point */
if (session->rsa_key) {
privatekey_free(session->rsa_key);
session->rsa_key = NULL;
}
if (session->dsa_key) {
privatekey_free(session->dsa_key);
session->dsa_key = NULL;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_KEXDH_REPLY) < 0 ||
buffer_add_ssh_string(session->out_buffer, pubkey) < 0 ||
buffer_add_ssh_string(session->out_buffer, f) < 0 ||
buffer_add_ssh_string(session->out_buffer, sign) < 0) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
buffer_free(session->out_buffer);
string_free(f);
string_free(sign);
return -1;
}
string_free(f);
string_free(sign);
if (packet_send(session) != SSH_OK) {
return -1;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS) < 0) {
buffer_free(session->out_buffer);
return -1;
}
if (packet_send(session) != SSH_OK) {
return -1;
}
ssh_log(session, SSH_LOG_PACKET, "SSH_MSG_NEWKEYS sent");
if (packet_wait(session, SSH2_MSG_NEWKEYS, 1) != SSH_OK) {
return -1;
}
ssh_log(session, SSH_LOG_PACKET, "Got SSH_MSG_NEWKEYS");
if (generate_session_keys(session) < 0) {
return -1;
}
/*
* Once we got SSH2_MSG_NEWKEYS we can switch next_crypto and
* current_crypto
*/
if (session->current_crypto) {
crypto_free(session->current_crypto);
}
/* FIXME TODO later, include a function to change keys */
session->current_crypto = session->next_crypto;
session->next_crypto = crypto_new();
if (session->next_crypto == NULL) {
return -1;
}
return 0;
}
static int dh_handshake(SSH_SESSION *session){
STRING *e,*f,*pubkey,*signature;
int ret;
switch(session->dh_handshake_state){
case DH_STATE_INIT:
packet_clear_out(session);
buffer_add_u8(session->out_buffer,SSH2_MSG_KEXDH_INIT);
dh_generate_x(session);
dh_generate_e(session);
e=dh_get_e(session);
buffer_add_ssh_string(session->out_buffer,e);
ret=packet_send(session);
free(e);
session->dh_handshake_state=DH_STATE_INIT_TO_SEND;
if(ret==SSH_ERROR)
return ret;
case DH_STATE_INIT_TO_SEND:
ret=packet_flush(session,0);
if(ret!=SSH_OK)
return ret; // SSH_ERROR or SSH_AGAIN
session->dh_handshake_state=DH_STATE_INIT_SENT;
case DH_STATE_INIT_SENT:
ret=packet_wait(session,SSH2_MSG_KEXDH_REPLY,1);
if(ret != SSH_OK)
return ret;
pubkey=buffer_get_ssh_string(session->in_buffer);
if(!pubkey){
ssh_set_error(session,SSH_FATAL,"No public key in packet");
return SSH_ERROR;
}
dh_import_pubkey(session,pubkey);
f=buffer_get_ssh_string(session->in_buffer);
if(!f){
ssh_set_error(session,SSH_FATAL,"No F number in packet");
return SSH_ERROR;
}
dh_import_f(session,f);
free(f);
if(!(signature=buffer_get_ssh_string(session->in_buffer))){
ssh_set_error(session,SSH_FATAL,"No signature in packet");
return SSH_ERROR;
}
session->dh_server_signature=signature;
dh_build_k(session);
// send the MSG_NEWKEYS
packet_clear_out(session);
buffer_add_u8(session->out_buffer,SSH2_MSG_NEWKEYS);
packet_send(session);
session->dh_handshake_state=DH_STATE_NEWKEYS_TO_SEND;
case DH_STATE_NEWKEYS_TO_SEND:
ret=packet_flush(session,0);
if(ret != SSH_OK)
return ret;
ssh_say(2,"SSH_MSG_NEWKEYS sent\n");
session->dh_handshake_state=DH_STATE_NEWKEYS_SENT;
case DH_STATE_NEWKEYS_SENT:
ret=packet_wait(session,SSH2_MSG_NEWKEYS,1);
if(ret != SSH_OK)
return ret;
ssh_say(2,"Got SSH_MSG_NEWKEYS\n");
make_sessionid(session);
/* set the cryptographic functions for the next crypto */
/* (it is needed for generate_session_keys for key lenghts) */
if(crypt_set_algorithms(session))
return SSH_ERROR;
generate_session_keys(session);
/* verify the host's signature. XXX do it sooner */
signature=session->dh_server_signature;
session->dh_server_signature=NULL;
if(signature_verify(session,signature)){
free(signature);
return SSH_ERROR;
}
free(signature); /* forget it for now ... */
/* once we got SSH2_MSG_NEWKEYS we can switch next_crypto and current_crypto */
if(session->current_crypto)
crypto_free(session->current_crypto);
/* XXX later, include a function to change keys */
session->current_crypto=session->next_crypto;
session->next_crypto=crypto_new();
session->dh_handshake_state=DH_STATE_FINISHED;
return SSH_OK;
default:
ssh_set_error(session,SSH_FATAL,"Invalid state in dh_handshake():%d",session->dh_handshake_state);
return SSH_ERROR;
}
/* not reached */
return SSH_ERROR;
}
static int dh_handshake_server(SSH_SESSION *session){
STRING *e,*f,*pubkey,*sign;
PUBLIC_KEY *pub;
PRIVATE_KEY *prv;
BUFFER *buf=buffer_new();
if(packet_wait(session, SSH2_MSG_KEXDH_INIT)) // FIXME BLOCKING
return -1;
e=buffer_get_ssh_string(session->in_buffer);
if(!e){
ssh_set_error(session,SSH_FATAL,"No e number in client request");
return -1;
}
dh_import_e(session,e);
dh_generate_y(session);
dh_generate_f(session);
f=dh_get_f(session);
switch(session->hostkeys){
case TYPE_DSS:
prv=session->dsa_key;
break;
case TYPE_RSA:
prv=session->rsa_key;
break;
default:
prv=NULL;
}
pub=publickey_from_privatekey(prv);
pubkey=publickey_to_string(pub);
publickey_free(pub);
dh_import_pubkey(session,pubkey);
dh_build_k(session);
make_sessionid(session);
sign=ssh_sign_session_id(session,prv);
buffer_free(buf);
/* free private keys as they should not be readable past this point */
if(session->rsa_key){
private_key_free(session->rsa_key);
session->rsa_key=NULL;
}
if(session->dsa_key){
private_key_free(session->dsa_key);
session->dsa_key=NULL;
}
buffer_add_u8(session->out_buffer,SSH2_MSG_KEXDH_REPLY);
buffer_add_ssh_string(session->out_buffer,pubkey);
buffer_add_ssh_string(session->out_buffer,f);
buffer_add_ssh_string(session->out_buffer,sign);
free(sign);
packet_send(session);
free(f);
packet_clear_out(session);
buffer_add_u8(session->out_buffer,SSH2_MSG_NEWKEYS);
packet_send(session);
ssh_say(2,"SSH_MSG_NEWKEYS sent\n");
packet_wait(session,SSH2_MSG_NEWKEYS);// FIXME BLOCKING
ssh_say(2,"Got SSH_MSG_NEWKEYS\n");
generate_session_keys(session);
/* once we got SSH2_MSG_NEWKEYS we can switch next_crypto and current_crypto */
if(session->current_crypto)
crypto_free(session->current_crypto);
/* XXX later, include a function to change keys */
session->current_crypto=session->next_crypto;
session->next_crypto=crypto_new();
return 0;
}
int ssh_get_kex1(SSH_SESSION *session){
u32 server_bits, host_bits, protocol_flags,
supported_ciphers_mask, supported_authentications_mask;
STRING *server_exp=NULL;
STRING *server_mod=NULL;
STRING *host_exp=NULL;
STRING *host_mod=NULL;
STRING *serverkey;
STRING *hostkey;
STRING *enc_session;
PUBLIC_KEY *svr,*host;
int ko;
u16 bits;
ssh_say(3,"Waiting for a SSH_SMSG_PUBLIC_KEY\n");
if(packet_wait(session,SSH_SMSG_PUBLIC_KEY,1)){
return -1;
}
ssh_say(3,"Got a SSH_SMSG_PUBLIC_KEY\n");
if(buffer_get_data(session->in_buffer,session->server_kex.cookie,8)!=8){
ssh_set_error(NULL,SSH_FATAL,"Can't get cookie in buffer");
return -1;
}
buffer_get_u32(session->in_buffer,&server_bits);
server_exp=buffer_get_mpint(session->in_buffer);
server_mod=buffer_get_mpint(session->in_buffer);
buffer_get_u32(session->in_buffer,&host_bits);
host_exp=buffer_get_mpint(session->in_buffer);
host_mod=buffer_get_mpint(session->in_buffer);
buffer_get_u32(session->in_buffer,&protocol_flags);
buffer_get_u32(session->in_buffer,&supported_ciphers_mask);
ko=buffer_get_u32(session->in_buffer,&supported_authentications_mask);
if((ko!=sizeof(u32)) || !host_mod || !host_exp || !server_mod || !server_exp){
ssh_say(2,"Invalid SSH_SMSG_PUBLIC_KEY packet\n");
ssh_set_error(NULL,SSH_FATAL,"Invalid SSH_SMSG_PUBLIC_KEY packet");
if(host_mod)
free(host_mod);
if(host_exp)
free(host_exp);
if(server_mod)
free(server_mod);
if(server_exp)
free(server_exp);
return -1;
}
server_bits=ntohl(server_bits);
host_bits=ntohl(host_bits);
protocol_flags=ntohl(protocol_flags);
supported_ciphers_mask=ntohl(supported_ciphers_mask);
supported_authentications_mask=ntohl(supported_authentications_mask);
ssh_say(1,"server bits: %d ; host bits: %d\nProtocol flags : %.8lx ; "
"cipher mask : %.8lx ; auth mask: %.8lx\n",server_bits,
host_bits,protocol_flags,supported_ciphers_mask,
supported_authentications_mask);
serverkey=make_rsa1_string(server_exp,server_mod);
hostkey=make_rsa1_string(host_exp,host_mod);
build_session_id1(session,server_mod,host_mod);
free(server_exp);
free(server_mod);
free(host_exp);
free(host_mod);
svr=publickey_from_string(serverkey);
host=publickey_from_string(hostkey);
session->next_crypto->server_pubkey=string_copy(hostkey);
session->next_crypto->server_pubkey_type="ssh-rsa1";
/* now, we must choose an encryption algo */
/* hardcode 3des */
if(!(supported_ciphers_mask & (1<<SSH_CIPHER_3DES))){
ssh_set_error(NULL,SSH_FATAL,"Remote server doesn't accept 3des");
return -1;
}
packet_clear_out(session);
buffer_add_u8(session->out_buffer,SSH_CMSG_SESSION_KEY);
buffer_add_u8(session->out_buffer,SSH_CIPHER_3DES);
buffer_add_data(session->out_buffer,session->server_kex.cookie,8);
enc_session=encrypt_session_key(session,svr,host,server_bits, host_bits);
bits=string_len(enc_session)*8 - 7;
ssh_say(2,"%d bits,%d bytes encrypted session\n",bits,string_len(enc_session));
bits=htons(bits);
/* the encrypted mpint */
buffer_add_data(session->out_buffer,&bits,sizeof(u16));
buffer_add_data(session->out_buffer,enc_session->string,
string_len(enc_session));
/* the protocol flags */
buffer_add_u32(session->out_buffer,0);
packet_send(session);
/* we can set encryption */
if(crypt_set_algorithms(session))
return -1;
session->current_crypto=session->next_crypto;
session->next_crypto=NULL;
if(packet_wait(session,SSH_SMSG_SUCCESS,1)){
char buffer[1024];
snprintf(buffer,sizeof(buffer),"Key exchange failed : %s",ssh_get_error(session));
ssh_set_error(session,SSH_FATAL,"%s",buffer);
return -1;
}
ssh_say(1,"received SSH_SMSG_SUCCESS\n");
return 0;
}