static int asn1_check_sequence(ssh_buffer buffer) {
unsigned char *j = NULL;
unsigned char tmp;
int i;
uint32_t size;
uint32_t padding;
if (ssh_buffer_get_data(buffer, &tmp, 1) == 0 || tmp != ASN1_SEQUENCE) {
return 0;
}
size = asn1_get_len(buffer);
if ((padding = ssh_buffer_get_len(buffer) - size) > 0) {
for (i = ssh_buffer_get_len(buffer) - size,
j = (unsigned char*)ssh_buffer_get(buffer) + size;
i;
i--, j++)
{
if (*j != padding) { /* padding is allowed */
return 0; /* but nothing else */
}
}
}
return 1;
}
/* this is a public key in openssh's format */
static ssh_string make_rsa1_string(ssh_string e, ssh_string n){
ssh_buffer buffer = NULL;
ssh_string rsa = NULL;
ssh_string ret = NULL;
buffer = ssh_buffer_new();
rsa = ssh_string_from_char("ssh-rsa1");
if (rsa == NULL) {
goto error;
}
if (ssh_buffer_add_ssh_string(buffer, rsa) < 0) {
goto error;
}
if (ssh_buffer_add_ssh_string(buffer, e) < 0) {
goto error;
}
if (ssh_buffer_add_ssh_string(buffer, n) < 0) {
goto error;
}
ret = ssh_string_new(ssh_buffer_get_len(buffer));
if (ret == NULL) {
goto error;
}
ssh_string_fill(ret, ssh_buffer_get(buffer), ssh_buffer_get_len(buffer));
error:
ssh_buffer_free(buffer);
ssh_string_free(rsa);
return ret;
}
/*
* Test if the continuously growing buffer size never exceeds 2 time its
* real capacity
*/
static void *thread_growing_buffer(void *threadid)
{
ssh_buffer buffer = NULL;
int i;
/* Unused */
(void) threadid;
/* Setup */
buffer = ssh_buffer_new();
if (buffer == NULL) {
pthread_exit((void *)-1);
}
ssh_buffer_set_secure(buffer);
for (i = 0; i < BUFFER_LIMIT; ++i) {
ssh_buffer_add_data(buffer,"A",1);
if (buffer->used >= 128) {
if (ssh_buffer_get_len(buffer) * 2 < buffer->allocated) {
assert_true(ssh_buffer_get_len(buffer) * 2 >= buffer->allocated);
}
}
}
/* Teardown */
SSH_BUFFER_FREE(buffer);
pthread_exit(NULL);
}
int ssh_pki_export_signature_blob(const ssh_signature sig,
ssh_string *sig_blob)
{
ssh_buffer buf = NULL;
ssh_string str;
int rc;
if (sig == NULL || sig_blob == NULL) {
return SSH_ERROR;
}
buf = ssh_buffer_new();
if (buf == NULL) {
return SSH_ERROR;
}
str = ssh_string_from_char(sig->type_c);
if (str == NULL) {
ssh_buffer_free(buf);
return SSH_ERROR;
}
rc = ssh_buffer_add_ssh_string(buf, str);
ssh_string_free(str);
if (rc < 0) {
ssh_buffer_free(buf);
return SSH_ERROR;
}
str = pki_signature_to_blob(sig);
if (str == NULL) {
ssh_buffer_free(buf);
return SSH_ERROR;
}
rc = ssh_buffer_add_ssh_string(buf, str);
ssh_string_free(str);
if (rc < 0) {
ssh_buffer_free(buf);
return SSH_ERROR;
}
str = ssh_string_new(ssh_buffer_get_len(buf));
if (str == NULL) {
ssh_buffer_free(buf);
return SSH_ERROR;
}
ssh_string_fill(str, ssh_buffer_get(buf), ssh_buffer_get_len(buf));
ssh_buffer_free(buf);
*sig_blob = str;
return SSH_OK;
}
int sftp_reply_names(sftp_client_message msg) {
ssh_buffer out;
out = ssh_buffer_new();
if (out == NULL) {
ssh_buffer_free(msg->attrbuf);
return -1;
}
if (ssh_buffer_add_u32(out, msg->id) < 0 ||
ssh_buffer_add_u32(out, htonl(msg->attr_num)) < 0 ||
ssh_buffer_add_data(out, ssh_buffer_get(msg->attrbuf),
ssh_buffer_get_len(msg->attrbuf)) < 0 ||
sftp_packet_write(msg->sftp, SSH_FXP_NAME, out) < 0) {
ssh_buffer_free(out);
ssh_buffer_free(msg->attrbuf);
return -1;
}
ssh_buffer_free(out);
ssh_buffer_free(msg->attrbuf);
msg->attr_num = 0;
msg->attrbuf = NULL;
return 0;
}
int ssh_socket_get_status(ssh_socket s) {
int r = 0;
if (ssh_buffer_get_len(s->in_buffer) > 0) {
r |= SSH_READ_PENDING;
}
if (ssh_buffer_get_len(s->out_buffer) > 0) {
r |= SSH_WRITE_PENDING;
}
if (s->data_except) {
r |= SSH_CLOSED_ERROR;
}
return r;
}
static int privatekey_decrypt(int algo, int mode, unsigned int key_len,
unsigned char *iv, unsigned int iv_len,
ssh_buffer data, ssh_auth_callback cb,
void *userdata,
const char *desc)
{
char passphrase[MAX_PASSPHRASE_SIZE] = {0};
unsigned char key[MAX_KEY_SIZE] = {0};
unsigned char *tmp = NULL;
gcry_cipher_hd_t cipher;
int rc = -1;
if (!algo) {
return -1;
}
if (cb) {
rc = (*cb)(desc, passphrase, MAX_PASSPHRASE_SIZE, 0, 0, userdata);
if (rc < 0) {
return -1;
}
} else if (cb == NULL && userdata != NULL) {
snprintf(passphrase, MAX_PASSPHRASE_SIZE, "%s", (char *) userdata);
}
if (passphrase_to_key(passphrase, strlen(passphrase), iv, key, key_len) < 0) {
return -1;
}
if (gcry_cipher_open(&cipher, algo, mode, 0)
|| gcry_cipher_setkey(cipher, key, key_len)
|| gcry_cipher_setiv(cipher, iv, iv_len)
|| (tmp = malloc(ssh_buffer_get_len(data) * sizeof (char))) == NULL
|| gcry_cipher_decrypt(cipher, tmp, ssh_buffer_get_len(data),
ssh_buffer_get(data), ssh_buffer_get_len(data))) {
gcry_cipher_close(cipher);
return -1;
}
memcpy(ssh_buffer_get(data), tmp, ssh_buffer_get_len(data));
SAFE_FREE(tmp);
gcry_cipher_close(cipher);
return 0;
}
/*
* This function places the outgoing packet buffer into an outgoing
* socket buffer
*/
static int ssh_packet_write(ssh_session session) {
int rc = SSH_ERROR;
rc=ssh_socket_write(session->socket,
ssh_buffer_get(session->out_buffer),
ssh_buffer_get_len(session->out_buffer));
return rc;
}
static void *thread_ssh_buffer_add_format(void *threadid)
{
ssh_buffer buffer = NULL;
uint8_t b;
uint16_t w;
uint32_t d;
uint64_t q;
ssh_string s = NULL;
int rc;
size_t len;
uint8_t verif[] = "\x42\x13\x37\x0b\xad\xc0\xde\x13\x24\x35\x46"
"\xac\xbd\xce\xdf"
"\x00\x00\x00\x06" "libssh"
"\x00\x00\x00\x05" "rocks"
"So much"
"Fun!";
/* Unused */
(void) threadid;
/* Setup */
buffer = ssh_buffer_new();
if (buffer == NULL) {
pthread_exit((void *)-1);
}
ssh_buffer_set_secure(buffer);
b = 0x42;
w = 0x1337;
d = 0xbadc0de;
q = 0x13243546acbdcedf;
s = ssh_string_from_char("libssh");
rc = ssh_buffer_pack(buffer,
"bwdqSsPt",
b,
w,
d,
q,
s,
"rocks",
7,
"So much",
"Fun!");
assert_int_equal(rc, SSH_OK);
len = ssh_buffer_get_len(buffer);
assert_int_equal(len, sizeof(verif) - 1);
assert_memory_equal(ssh_buffer_get(buffer), verif, sizeof(verif) -1);
SSH_STRING_FREE(s);
/* Teardown */
SSH_BUFFER_FREE(buffer);
pthread_exit(NULL);
}
/*
* Test the behavior of ssh_buffer_prepend_data
*/
static void *thread_buffer_prepend(void *threadid)
{
ssh_buffer buffer = NULL;
uint32_t v;
/* Unused */
(void) threadid;
/* Setup */
buffer = ssh_buffer_new();
if (buffer == NULL) {
pthread_exit((void *)-1);
}
ssh_buffer_set_secure(buffer);
ssh_buffer_add_data(buffer, "abcdef", 6);
ssh_buffer_prepend_data(buffer, "xyz", 3);
assert_int_equal(ssh_buffer_get_len(buffer), 9);
assert_memory_equal(ssh_buffer_get(buffer), "xyzabcdef", 9);
/* Now remove 4 bytes and see if we can replace them */
ssh_buffer_get_u32(buffer, &v);
assert_int_equal(ssh_buffer_get_len(buffer), 5);
assert_memory_equal(ssh_buffer_get(buffer), "bcdef", 5);
ssh_buffer_prepend_data(buffer, "aris", 4);
assert_int_equal(ssh_buffer_get_len(buffer), 9);
assert_memory_equal(ssh_buffer_get(buffer), "arisbcdef", 9);
/* same thing but we add 5 bytes now */
ssh_buffer_get_u32(buffer, &v);
assert_int_equal(ssh_buffer_get_len(buffer), 5);
assert_memory_equal(ssh_buffer_get(buffer), "bcdef", 5);
ssh_buffer_prepend_data(buffer, "12345", 5);
assert_int_equal(ssh_buffer_get_len(buffer), 10);
assert_memory_equal(ssh_buffer_get(buffer), "12345bcdef", 10);
/* Teardown */
SSH_BUFFER_FREE(buffer);
pthread_exit(NULL);
}
/*
* Test if the continuously growing buffer size never exceeds 2 time its
* real capacity, when we remove 1 byte after each call (sliding window)
*/
static void *thread_growing_buffer_shifting(void *threadid)
{
ssh_buffer buffer;
int i;
unsigned char c;
/* Unused */
(void) threadid;
/* Setup */
buffer = ssh_buffer_new();
if (buffer == NULL) {
pthread_exit((void *)-1);
}
ssh_buffer_set_secure(buffer);
for (i = 0; i < 1024; ++i) {
ssh_buffer_add_data(buffer,"S",1);
}
for (i = 0; i < BUFFER_LIMIT; ++i) {
ssh_buffer_get_u8(buffer,&c);
ssh_buffer_add_data(buffer,"A",1);
if (buffer->used >= 128) {
if (ssh_buffer_get_len(buffer) * 4 < buffer->allocated) {
assert_true(ssh_buffer_get_len(buffer) * 4 >= buffer->allocated);
/* Teardown */
SSH_BUFFER_FREE(buffer);
pthread_exit(NULL);
}
}
}
/* Teardown */
SSH_BUFFER_FREE(buffer);
pthread_exit(NULL);
}
static int ssh_gssapi_send_mic(ssh_session session){
OM_uint32 maj_stat, min_stat;
gss_buffer_desc mic_buf = GSS_C_EMPTY_BUFFER;
gss_buffer_desc mic_token_buf = GSS_C_EMPTY_BUFFER;
ssh_buffer mic_buffer;
int rc;
SSH_LOG(SSH_LOG_PACKET,"Sending SSH_MSG_USERAUTH_GSSAPI_MIC");
mic_buffer = ssh_gssapi_build_mic(session);
if (mic_buffer == NULL) {
ssh_set_error_oom(session);
return SSH_ERROR;
}
mic_buf.length = ssh_buffer_get_len(mic_buffer);
mic_buf.value = ssh_buffer_get_begin(mic_buffer);
maj_stat = gss_get_mic(&min_stat,session->gssapi->ctx, GSS_C_QOP_DEFAULT, &mic_buf, &mic_token_buf);
if (GSS_ERROR(maj_stat)){
ssh_buffer_free(mic_buffer);
ssh_gssapi_log_error(0, "generating MIC", maj_stat);
return SSH_ERROR;
}
rc = buffer_add_u8(session->out_buffer, SSH2_MSG_USERAUTH_GSSAPI_MIC);
if (rc < 0) {
ssh_buffer_free(mic_buffer);
ssh_set_error_oom(session);
return SSH_ERROR;
}
rc = buffer_add_u32(session->out_buffer, htonl(mic_token_buf.length));
if (rc < 0) {
ssh_buffer_free(mic_buffer);
ssh_set_error_oom(session);
return SSH_ERROR;
}
rc = buffer_add_data(session->out_buffer, mic_token_buf.value, mic_token_buf.length);
ssh_buffer_free(mic_buffer);
if (rc < 0) {
ssh_set_error_oom(session);
return SSH_ERROR;
}
return packet_send(session);
}
/**
* @internal
*
* @brief Verify the hmac of a packet
*
* @param session The session to use.
* @param buffer The buffer to verify the hmac from.
* @param mac The mac to compare with the hmac.
*
* @return 0 if hmac and mac are equal, < 0 if not or an error
* occurred.
*/
int ssh_packet_hmac_verify(ssh_session session,
ssh_buffer buffer,
uint8_t *mac,
enum ssh_hmac_e type)
{
unsigned char hmacbuf[DIGEST_MAX_LEN] = {0};
HMACCTX ctx;
unsigned int len;
uint32_t seq;
/* AEAD type have no mac checking */
if (type == SSH_HMAC_AEAD_POLY1305) {
return SSH_OK;
}
ctx = hmac_init(session->current_crypto->decryptMAC, hmac_digest_len(type), type);
if (ctx == NULL) {
return -1;
}
seq = htonl(session->recv_seq);
hmac_update(ctx, (unsigned char *) &seq, sizeof(uint32_t));
hmac_update(ctx, ssh_buffer_get(buffer), ssh_buffer_get_len(buffer));
hmac_final(ctx, hmacbuf, &len);
#ifdef DEBUG_CRYPTO
ssh_print_hexa("received mac",mac,len);
ssh_print_hexa("Computed mac",hmacbuf,len);
ssh_print_hexa("seq",(unsigned char *)&seq,sizeof(uint32_t));
#endif
if (secure_memcmp(mac, hmacbuf, len) == 0) {
return 0;
}
return -1;
}
static int ssh_gssapi_send_mic(ssh_session session){
OM_uint32 maj_stat, min_stat;
gss_buffer_desc mic_buf = GSS_C_EMPTY_BUFFER;
gss_buffer_desc mic_token_buf = GSS_C_EMPTY_BUFFER;
ssh_buffer mic_buffer;
int rc;
SSH_LOG(SSH_LOG_PACKET,"Sending SSH_MSG_USERAUTH_GSSAPI_MIC");
mic_buffer = ssh_gssapi_build_mic(session);
if (mic_buffer == NULL) {
ssh_set_error_oom(session);
return SSH_ERROR;
}
mic_buf.length = ssh_buffer_get_len(mic_buffer);
mic_buf.value = ssh_buffer_get_begin(mic_buffer);
maj_stat = gss_get_mic(&min_stat,session->gssapi->ctx, GSS_C_QOP_DEFAULT, &mic_buf, &mic_token_buf);
if (GSS_ERROR(maj_stat)){
ssh_buffer_free(mic_buffer);
ssh_gssapi_log_error(SSH_LOG_PROTOCOL, "generating MIC", maj_stat);
return SSH_ERROR;
}
rc = ssh_buffer_pack(session->out_buffer,
"bdP",
SSH2_MSG_USERAUTH_GSSAPI_MIC,
mic_token_buf.length,
(size_t)mic_token_buf.length, mic_token_buf.value);
if (rc != SSH_OK) {
ssh_buffer_free(mic_buffer);
ssh_set_error_oom(session);
return SSH_ERROR;
}
return packet_send(session);
}
/** @internal
* @brief encrypts an ed25519 private key blob
*
*/
static int pki_private_key_encrypt(ssh_buffer privkey_buffer,
const char* passphrase,
const char *ciphername,
const char *kdfname,
ssh_auth_callback auth_fn,
void *auth_data,
uint32_t rounds,
ssh_string salt)
{
struct ssh_cipher_struct *ciphers = ssh_get_ciphertab();
struct ssh_cipher_struct cipher;
uint8_t key_material[128];
size_t key_material_len;
char passphrase_buffer[128];
int rc;
int i;
uint8_t padding = 1;
int cmp;
cmp = strcmp(ciphername, "none");
if (cmp == 0){
/* no encryption required */
return SSH_OK;
}
for (i = 0; ciphers[i].name != NULL; i++) {
cmp = strcmp(ciphername, ciphers[i].name);
if (cmp == 0){
memcpy(&cipher, &ciphers[i], sizeof(cipher));
break;
}
}
if (ciphers[i].name == NULL){
SSH_LOG(SSH_LOG_WARN, "Unsupported cipher %s", ciphername);
return SSH_ERROR;
}
cmp = strcmp(kdfname, "bcrypt");
if (cmp != 0){
SSH_LOG(SSH_LOG_WARN, "Unsupported KDF %s", kdfname);
return SSH_ERROR;
}
while (ssh_buffer_get_len(privkey_buffer) % cipher.blocksize != 0) {
rc = buffer_add_u8(privkey_buffer, padding);
if (rc < 0) {
return SSH_ERROR;
}
padding++;
}
/* We need material for key (keysize bits / 8) and IV (blocksize) */
key_material_len = cipher.keysize/8 + cipher.blocksize;
if (key_material_len > sizeof(key_material)){
ssh_pki_log("Key material too big");
return SSH_ERROR;
}
ssh_pki_log("Encryption: %d key, %d IV, %d rounds, %zu bytes salt",
cipher.keysize/8,
cipher.blocksize, rounds, ssh_string_len(salt));
if (passphrase == NULL){
if (auth_fn == NULL){
ssh_pki_log("No passphrase provided");
return SSH_ERROR;
}
rc = auth_fn("Passphrase",
passphrase_buffer,
sizeof(passphrase_buffer),
0,
0,
auth_data);
if (rc != SSH_OK){
return SSH_ERROR;
}
passphrase = passphrase_buffer;
}
rc = bcrypt_pbkdf(passphrase,
strlen(passphrase),
ssh_string_data(salt),
ssh_string_len(salt),
key_material,
key_material_len,
rounds);
if (rc < 0){
return SSH_ERROR;
}
cipher.set_encrypt_key(&cipher,
key_material,
key_material + cipher.keysize/8);
cipher.encrypt(&cipher,
ssh_buffer_get_begin(privkey_buffer),
ssh_buffer_get_begin(privkey_buffer),
ssh_buffer_get_len(privkey_buffer));
ssh_cipher_clear(&cipher);
BURN_BUFFER(passphrase_buffer, sizeof(passphrase_buffer));
return SSH_OK;
}
int ssh_packet_send1(ssh_session session) {
unsigned int blocksize = (session->current_crypto ?
session->current_crypto->out_cipher->blocksize : 8);
uint32_t currentlen = ssh_buffer_get_len(session->out_buffer) + sizeof(uint32_t);
char padstring[32] = {0};
int rc = SSH_ERROR;
uint32_t finallen;
uint32_t crc;
uint8_t padding;
SSH_LOG(SSH_LOG_PACKET,"Sending a %d bytes long packet",currentlen);
/* TODO FIXME
#ifdef WITH_ZLIB
if (session->current_crypto && session->current_crypto->do_compress_out) {
if (compress_buffer(session, session->out_buffer) < 0) {
goto error;
}
currentlen = ssh_buffer_get_len(session->out_buffer);
}
#endif
*/
padding = blocksize - (currentlen % blocksize);
if (session->current_crypto) {
ssh_get_random(padstring, padding, 0);
} else {
memset(padstring, 0, padding);
}
finallen = htonl(currentlen);
SSH_LOG(SSH_LOG_PACKET,
"%d bytes after comp + %d padding bytes = %d bytes packet",
currentlen, padding, ntohl(finallen));
if (ssh_buffer_prepend_data(session->out_buffer, &padstring, padding) < 0) {
goto error;
}
if (ssh_buffer_prepend_data(session->out_buffer, &finallen, sizeof(uint32_t)) < 0) {
goto error;
}
crc = ssh_crc32((char *)ssh_buffer_get(session->out_buffer) + sizeof(uint32_t),
ssh_buffer_get_len(session->out_buffer) - sizeof(uint32_t));
if (ssh_buffer_add_u32(session->out_buffer, ntohl(crc)) < 0) {
goto error;
}
#ifdef DEBUG_CRYPTO
ssh_print_hexa("Clear packet", ssh_buffer_get(session->out_buffer),
ssh_buffer_get_len(session->out_buffer));
#endif
/* session->out_buffer should have more than sizeof(uint32_t) bytes
in it as required for ssh_packet_encrypt */
ssh_packet_encrypt(session, (unsigned char *)ssh_buffer_get(session->out_buffer) + sizeof(uint32_t),
ssh_buffer_get_len(session->out_buffer) - sizeof(uint32_t));
#ifdef DEBUG_CRYPTO
ssh_print_hexa("encrypted packet",ssh_buffer_get(session->out_buffer),
ssh_buffer_get_len(session->out_buffer));
#endif
rc=ssh_socket_write(session->socket, ssh_buffer_get(session->out_buffer),
ssh_buffer_get_len(session->out_buffer));
if(rc== SSH_ERROR) {
goto error;
}
session->send_seq++;
if (ssh_buffer_reinit(session->out_buffer) < 0) {
rc = SSH_ERROR;
}
error:
return rc; /* SSH_OK, AGAIN or ERROR */
}
int ssh_packet_socket_callback1(const void *data, size_t receivedlen, void *user) {
void *packet = NULL;
int to_be_read;
size_t processed=0;
uint32_t padding;
uint32_t crc;
uint32_t len, buffer_len;
ssh_session session=(ssh_session)user;
switch (session->packet_state){
case PACKET_STATE_INIT:
memset(&session->in_packet, 0, sizeof(PACKET));
if (session->in_buffer) {
if (ssh_buffer_reinit(session->in_buffer) < 0) {
goto error;
}
} else {
session->in_buffer = ssh_buffer_new();
if (session->in_buffer == NULL) {
goto error;
}
}
/* must have at least enough bytes for size */
if(receivedlen < sizeof(uint32_t)){
return 0;
}
memcpy(&len,data,sizeof(uint32_t));
processed += sizeof(uint32_t);
/* len is not encrypted */
len = ntohl(len);
if (len > MAX_PACKET_LEN) {
ssh_set_error(session, SSH_FATAL,
"read_packet(): Packet len too high (%u %.8x)", len, len);
goto error;
}
SSH_LOG(SSH_LOG_PACKET, "Reading a %d bytes packet", len);
session->in_packet.len = len;
session->packet_state = PACKET_STATE_SIZEREAD;
/* FALL THROUGH */
case PACKET_STATE_SIZEREAD:
len = session->in_packet.len;
/* SSH-1 has a fixed padding lenght */
padding = 8 - (len % 8);
to_be_read = len + padding;
if(to_be_read + processed > receivedlen){
/* wait for rest of packet */
return processed;
}
/* it is _not_ possible that to_be_read be < 8. */
packet = (char *)data + processed;
if (ssh_buffer_add_data(session->in_buffer,packet,to_be_read) < 0) {
goto error;
}
processed += to_be_read;
#ifdef DEBUG_CRYPTO
ssh_print_hexa("read packet:", ssh_buffer_get(session->in_buffer),
ssh_buffer_get_len(session->in_buffer));
#endif
if (session->current_crypto) {
/*
* We decrypt everything, missing the lenght part (which was
* previously read, unencrypted, and is not part of the buffer
*/
buffer_len = ssh_buffer_get_len(session->in_buffer);
if (buffer_len > 0) {
int rc;
rc = ssh_packet_decrypt(session,
ssh_buffer_get(session->in_buffer),
buffer_len);
if (rc < 0) {
ssh_set_error(session, SSH_FATAL, "Packet decrypt error");
goto error;
}
}
}
#ifdef DEBUG_CRYPTO
ssh_print_hexa("read packet decrypted:", ssh_buffer_get(session->in_buffer),
ssh_buffer_get_len(session->in_buffer));
#endif
SSH_LOG(SSH_LOG_PACKET, "%d bytes padding", padding);
if(((len + padding) != ssh_buffer_get_len(session->in_buffer)) ||
((len + padding) < sizeof(uint32_t))) {
SSH_LOG(SSH_LOG_RARE, "no crc32 in packet");
ssh_set_error(session, SSH_FATAL, "no crc32 in packet");
goto error;
}
memcpy(&crc,
(unsigned char *)ssh_buffer_get(session->in_buffer) + (len+padding) - sizeof(uint32_t),
sizeof(uint32_t));
ssh_buffer_pass_bytes_end(session->in_buffer, sizeof(uint32_t));
crc = ntohl(crc);
if (ssh_crc32(ssh_buffer_get(session->in_buffer),
(len + padding) - sizeof(uint32_t)) != crc) {
#ifdef DEBUG_CRYPTO
ssh_print_hexa("crc32 on",ssh_buffer_get(session->in_buffer),
len + padding - sizeof(uint32_t));
#endif
SSH_LOG(SSH_LOG_RARE, "Invalid crc32");
ssh_set_error(session, SSH_FATAL,
"Invalid crc32: expected %.8x, got %.8x",
crc,
ssh_crc32(ssh_buffer_get(session->in_buffer),
len + padding - sizeof(uint32_t)));
goto error;
}
/* pass the padding */
ssh_buffer_pass_bytes(session->in_buffer, padding);
SSH_LOG(SSH_LOG_PACKET, "The packet is valid");
/* TODO FIXME
#ifdef WITH_ZLIB
if(session->current_crypto && session->current_crypto->do_compress_in){
decompress_buffer(session,session->in_buffer);
}
#endif
*/
session->recv_seq++;
/* We don't want to rewrite a new packet while still executing the packet callbacks */
session->packet_state = PACKET_STATE_PROCESSING;
ssh_packet_parse_type(session);
/* execute callbacks */
ssh_packet_process(session, session->in_packet.type);
session->packet_state = PACKET_STATE_INIT;
if(processed < receivedlen){
int rc;
/* Handle a potential packet left in socket buffer */
SSH_LOG(SSH_LOG_PACKET,"Processing %" PRIdS " bytes left in socket buffer",
receivedlen-processed);
rc = ssh_packet_socket_callback1((char *)data + processed,
receivedlen - processed,user);
processed += rc;
}
return processed;
case PACKET_STATE_PROCESSING:
SSH_LOG(SSH_LOG_PACKET, "Nested packet processing. Delaying.");
return 0;
}
error:
session->session_state=SSH_SESSION_STATE_ERROR;
return processed;
}
ssh_string ssh_pki_openssh_privkey_export(const ssh_key privkey,
const char *passphrase,
ssh_auth_callback auth_fn,
void *auth_data)
{
ssh_buffer buffer;
ssh_string str = NULL;
ssh_string pubkey_s=NULL;
ssh_buffer privkey_buffer = NULL;
uint32_t rnd;
uint32_t rounds = 16;
ssh_string salt=NULL;
ssh_string kdf_options=NULL;
int to_encrypt=0;
unsigned char *b64;
uint32_t str_len, len;
int rc;
if (privkey == NULL) {
return NULL;
}
if (privkey->type != SSH_KEYTYPE_ED25519){
ssh_pki_log("Unsupported key type %s", privkey->type_c);
return NULL;
}
if (passphrase != NULL || auth_fn != NULL){
ssh_pki_log("Enabling encryption for private key export");
to_encrypt = 1;
}
buffer = ssh_buffer_new();
pubkey_s = pki_publickey_to_blob(privkey);
if(buffer == NULL || pubkey_s == NULL){
goto error;
}
ssh_get_random(&rnd, sizeof(rnd), 0);
privkey_buffer = ssh_buffer_new();
if (privkey_buffer == NULL) {
goto error;
}
/* checkint1 & 2 */
rc = ssh_buffer_pack(privkey_buffer,
"dd",
rnd,
rnd);
if (rc == SSH_ERROR){
goto error;
}
rc = pki_openssh_export_privkey_blob(privkey, privkey_buffer);
if (rc == SSH_ERROR){
goto error;
}
/* comment */
rc = ssh_buffer_pack(privkey_buffer, "s", "" /* comment */);
if (rc == SSH_ERROR){
goto error;
}
if (to_encrypt){
ssh_buffer kdf_buf;
kdf_buf = ssh_buffer_new();
if (kdf_buf == NULL) {
goto error;
}
salt = ssh_string_new(16);
if (salt == NULL){
ssh_buffer_free(kdf_buf);
goto error;
}
ssh_get_random(ssh_string_data(salt),16, 0);
ssh_buffer_pack(kdf_buf, "Sd", salt, rounds);
kdf_options = ssh_string_new(ssh_buffer_get_len(kdf_buf));
if (kdf_options == NULL){
ssh_buffer_free(kdf_buf);
goto error;
}
memcpy(ssh_string_data(kdf_options),
ssh_buffer_get_begin(kdf_buf),
ssh_buffer_get_len(kdf_buf));
ssh_buffer_free(kdf_buf);
rc = pki_private_key_encrypt(privkey_buffer,
passphrase,
"aes128-cbc",
"bcrypt",
auth_fn,
auth_data,
rounds,
salt);
if (rc != SSH_OK){
goto error;
}
} else {
kdf_options = ssh_string_new(0);
}
rc = ssh_buffer_pack(buffer,
"PssSdSdP",
(size_t)strlen(OPENSSH_AUTH_MAGIC) + 1, OPENSSH_AUTH_MAGIC,
to_encrypt ? "aes128-cbc" : "none", /* ciphername */
to_encrypt ? "bcrypt" : "none", /* kdfname */
kdf_options, /* kdfoptions */
(uint32_t) 1, /* nkeys */
pubkey_s,
(uint32_t)ssh_buffer_get_len(privkey_buffer),
/* rest of buffer is a string */
(size_t)ssh_buffer_get_len(privkey_buffer), ssh_buffer_get_begin(privkey_buffer));
if (rc != SSH_OK) {
goto error;
}
b64 = bin_to_base64(ssh_buffer_get_begin(buffer),
ssh_buffer_get_len(buffer));
if (b64 == NULL){
goto error;
}
/* we can reuse the buffer */
ssh_buffer_reinit(buffer);
rc = ssh_buffer_pack(buffer,
"tttttt",
OPENSSH_HEADER_BEGIN,
"\n",
b64,
"\n",
OPENSSH_HEADER_END,
"\n");
BURN_BUFFER(b64, strlen((char *)b64));
SAFE_FREE(b64);
if (rc != SSH_OK){
goto error;
}
str = ssh_string_new(ssh_buffer_get_len(buffer));
if (str == NULL){
goto error;
}
str_len = ssh_buffer_get_len(buffer);
len = buffer_get_data(buffer, ssh_string_data(str), str_len);
if (str_len != len) {
ssh_string_free(str);
str = NULL;
}
error:
if (privkey_buffer != NULL) {
void *bufptr = ssh_buffer_get_begin(privkey_buffer);
BURN_BUFFER(bufptr, ssh_buffer_get_len(privkey_buffer));
ssh_buffer_free(privkey_buffer);
}
SAFE_FREE(pubkey_s);
SAFE_FREE(kdf_options);
SAFE_FREE(salt);
if (buffer != NULL) {
ssh_buffer_free(buffer);
}
return str;
}
sftp_client_message sftp_get_client_message(sftp_session sftp) {
ssh_session session = sftp->session;
sftp_packet packet;
sftp_client_message msg;
ssh_buffer payload;
int rc;
msg = malloc(sizeof (struct sftp_client_message_struct));
if (msg == NULL) {
ssh_set_error_oom(session);
return NULL;
}
ZERO_STRUCTP(msg);
packet = sftp_packet_read(sftp);
if (packet == NULL) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
payload = packet->payload;
msg->type = packet->type;
msg->sftp = sftp;
/* take a copy of the whole packet */
msg->complete_message = ssh_buffer_new();
ssh_buffer_add_data(msg->complete_message,
ssh_buffer_get(payload),
ssh_buffer_get_len(payload));
ssh_buffer_get_u32(payload, &msg->id);
switch(msg->type) {
case SSH_FXP_CLOSE:
case SSH_FXP_READDIR:
msg->handle = ssh_buffer_get_ssh_string(payload);
if (msg->handle == NULL) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_READ:
rc = ssh_buffer_unpack(payload,
"Sqd",
&msg->handle,
&msg->offset,
&msg->len);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_WRITE:
rc = ssh_buffer_unpack(payload,
"SqS",
&msg->handle,
&msg->offset,
&msg->data);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_REMOVE:
case SSH_FXP_RMDIR:
case SSH_FXP_OPENDIR:
case SSH_FXP_READLINK:
case SSH_FXP_REALPATH:
rc = ssh_buffer_unpack(payload,
"s",
&msg->filename);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_RENAME:
case SSH_FXP_SYMLINK:
rc = ssh_buffer_unpack(payload,
"sS",
&msg->filename,
&msg->data);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_MKDIR:
case SSH_FXP_SETSTAT:
rc = ssh_buffer_unpack(payload,
"s",
&msg->filename);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
msg->attr = sftp_parse_attr(sftp, payload, 0);
if (msg->attr == NULL) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_FSETSTAT:
msg->handle = ssh_buffer_get_ssh_string(payload);
if (msg->handle == NULL) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
msg->attr = sftp_parse_attr(sftp, payload, 0);
if (msg->attr == NULL) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_LSTAT:
case SSH_FXP_STAT:
rc = ssh_buffer_unpack(payload,
"s",
&msg->filename);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
if(sftp->version > 3) {
ssh_buffer_unpack(payload, "d", &msg->flags);
}
break;
case SSH_FXP_OPEN:
rc = ssh_buffer_unpack(payload,
"sd",
&msg->filename,
&msg->flags);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
msg->attr = sftp_parse_attr(sftp, payload, 0);
if (msg->attr == NULL) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
case SSH_FXP_FSTAT:
rc = ssh_buffer_unpack(payload,
"S",
&msg->handle);
if (rc != SSH_OK) {
ssh_set_error_oom(session);
sftp_client_message_free(msg);
return NULL;
}
break;
default:
ssh_set_error(sftp->session, SSH_FATAL,
"Received unhandled sftp message %d", msg->type);
sftp_client_message_free(msg);
return NULL;
}
sftp_packet_free(packet);
return msg;
}
/** @internal
* @handles a data received event. It then calls the handlers for the different packet types
* or and exception handler callback.
* @param user pointer to current ssh_session
* @param data pointer to the data received
* @len length of data received. It might not be enough for a complete packet
* @returns number of bytes read and processed.
*/
int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
{
ssh_session session= (ssh_session) user;
unsigned int blocksize = (session->current_crypto ?
session->current_crypto->in_cipher->blocksize : 8);
unsigned char mac[DIGEST_MAX_LEN] = {0};
char buffer[16] = {0};
size_t current_macsize = 0;
const uint8_t *packet;
int to_be_read;
int rc;
uint32_t len, compsize, payloadsize;
uint8_t padding;
size_t processed = 0; /* number of byte processed from the callback */
if(session->current_crypto != NULL) {
current_macsize = hmac_digest_len(session->current_crypto->in_hmac);
}
if (data == NULL) {
goto error;
}
if (session->session_state == SSH_SESSION_STATE_ERROR) {
goto error;
}
switch(session->packet_state) {
case PACKET_STATE_INIT:
if (receivedlen < blocksize) {
/*
* We didn't receive enough data to read at least one
* block size, give up
*/
return 0;
}
memset(&session->in_packet, 0, sizeof(PACKET));
if (session->in_buffer) {
rc = ssh_buffer_reinit(session->in_buffer);
if (rc < 0) {
goto error;
}
} else {
session->in_buffer = ssh_buffer_new();
if (session->in_buffer == NULL) {
goto error;
}
}
memcpy(buffer, data, blocksize);
processed += blocksize;
len = ssh_packet_decrypt_len(session, buffer);
rc = ssh_buffer_add_data(session->in_buffer, buffer, blocksize);
if (rc < 0) {
goto error;
}
if (len > MAX_PACKET_LEN) {
ssh_set_error(session,
SSH_FATAL,
"read_packet(): Packet len too high(%u %.4x)",
len, len);
goto error;
}
to_be_read = len - blocksize + sizeof(uint32_t);
if (to_be_read < 0) {
/* remote sshd sends invalid sizes? */
ssh_set_error(session,
SSH_FATAL,
"Given numbers of bytes left to be read < 0 (%d)!",
to_be_read);
goto error;
}
/* Saves the status of the current operations */
session->in_packet.len = len;
session->packet_state = PACKET_STATE_SIZEREAD;
/* FALL TROUGH */
case PACKET_STATE_SIZEREAD:
len = session->in_packet.len;
to_be_read = len - blocksize + sizeof(uint32_t) + current_macsize;
/* if to_be_read is zero, the whole packet was blocksize bytes. */
if (to_be_read != 0) {
if (receivedlen - processed < (unsigned int)to_be_read) {
/* give up, not enough data in buffer */
SSH_LOG(SSH_LOG_PACKET,"packet: partial packet (read len) [len=%d]",len);
return processed;
}
packet = ((uint8_t*)data) + processed;
#if 0
ssh_socket_read(session->socket,
packet,
to_be_read - current_macsize);
#endif
rc = ssh_buffer_add_data(session->in_buffer,
packet,
to_be_read - current_macsize);
if (rc < 0) {
goto error;
}
processed += to_be_read - current_macsize;
}
if (session->current_crypto) {
/*
* Decrypt the rest of the packet (blocksize bytes already
* have been decrypted)
*/
uint32_t buffer_len = ssh_buffer_get_len(session->in_buffer);
/* The following check avoids decrypting zero bytes */
if (buffer_len > blocksize) {
uint8_t *payload = ((uint8_t*)ssh_buffer_get(session->in_buffer) + blocksize);
uint32_t plen = buffer_len - blocksize;
rc = ssh_packet_decrypt(session, payload, plen);
if (rc < 0) {
ssh_set_error(session, SSH_FATAL, "Decrypt error");
goto error;
}
}
/* copy the last part from the incoming buffer */
packet = ((uint8_t *)data) + processed;
memcpy(mac, packet, current_macsize);
rc = ssh_packet_hmac_verify(session, session->in_buffer, mac, session->current_crypto->in_hmac);
if (rc < 0) {
ssh_set_error(session, SSH_FATAL, "HMAC error");
goto error;
}
processed += current_macsize;
}
/* skip the size field which has been processed before */
ssh_buffer_pass_bytes(session->in_buffer, sizeof(uint32_t));
rc = ssh_buffer_get_u8(session->in_buffer, &padding);
if (rc == 0) {
ssh_set_error(session,
SSH_FATAL,
"Packet too short to read padding");
goto error;
}
if (padding > ssh_buffer_get_len(session->in_buffer)) {
ssh_set_error(session,
SSH_FATAL,
"Invalid padding: %d (%d left)",
padding,
ssh_buffer_get_len(session->in_buffer));
goto error;
}
ssh_buffer_pass_bytes_end(session->in_buffer, padding);
compsize = ssh_buffer_get_len(session->in_buffer);
#ifdef WITH_ZLIB
if (session->current_crypto
&& session->current_crypto->do_compress_in
&& ssh_buffer_get_len(session->in_buffer) > 0) {
rc = decompress_buffer(session, session->in_buffer,MAX_PACKET_LEN);
if (rc < 0) {
goto error;
}
}
#endif /* WITH_ZLIB */
payloadsize = ssh_buffer_get_len(session->in_buffer);
session->recv_seq++;
if (session->raw_counter != NULL) {
session->raw_counter->in_bytes += payloadsize;
session->raw_counter->in_packets++;
}
/*
* We don't want to rewrite a new packet while still executing the
* packet callbacks
*/
session->packet_state = PACKET_STATE_PROCESSING;
ssh_packet_parse_type(session);
SSH_LOG(SSH_LOG_PACKET,
"packet: read type %hhd [len=%d,padding=%hhd,comp=%d,payload=%d]",
session->in_packet.type, len, padding, compsize, payloadsize);
/* Execute callbacks */
ssh_packet_process(session, session->in_packet.type);
session->packet_state = PACKET_STATE_INIT;
if (processed < receivedlen) {
/* Handle a potential packet left in socket buffer */
SSH_LOG(SSH_LOG_PACKET,
"Processing %" PRIdS " bytes left in socket buffer",
receivedlen-processed);
packet = ((uint8_t*)data) + processed;
rc = ssh_packet_socket_callback(packet, receivedlen - processed,user);
processed += rc;
}
return processed;
case PACKET_STATE_PROCESSING:
SSH_LOG(SSH_LOG_PACKET, "Nested packet processing. Delaying.");
return 0;
}
ssh_set_error(session,
SSH_FATAL,
"Invalid state into packet_read2(): %d",
session->packet_state);
error:
session->session_state= SSH_SESSION_STATE_ERROR;
return processed;
}
int make_sessionid(ssh_session session) {
ssh_string num = NULL;
ssh_buffer server_hash = NULL;
ssh_buffer client_hash = NULL;
ssh_buffer buf = NULL;
int rc = SSH_ERROR;
buf = ssh_buffer_new();
if (buf == NULL) {
return rc;
}
rc = ssh_buffer_pack(buf,
"ss",
session->clientbanner,
session->serverbanner);
if (rc == SSH_ERROR) {
goto error;
}
if (session->client) {
server_hash = session->in_hashbuf;
client_hash = session->out_hashbuf;
} else {
server_hash = session->out_hashbuf;
client_hash = session->in_hashbuf;
}
/*
* Handle the two final fields for the KEXINIT message (RFC 4253 7.1):
*
* boolean first_kex_packet_follows
* uint32 0 (reserved for future extension)
*/
rc = buffer_add_u8(server_hash, 0);
if (rc < 0) {
goto error;
}
rc = buffer_add_u32(server_hash, 0);
if (rc < 0) {
goto error;
}
/* These fields are handled for the server case in ssh_packet_kexinit. */
if (session->client) {
rc = buffer_add_u8(client_hash, 0);
if (rc < 0) {
goto error;
}
rc = buffer_add_u32(client_hash, 0);
if (rc < 0) {
goto error;
}
}
rc = ssh_buffer_pack(buf,
"dPdPS",
buffer_get_rest_len(client_hash),
buffer_get_rest_len(client_hash),
buffer_get_rest(client_hash),
buffer_get_rest_len(server_hash),
buffer_get_rest_len(server_hash),
buffer_get_rest(server_hash),
session->next_crypto->server_pubkey);
if(rc != SSH_OK){
goto error;
}
if (session->next_crypto->kex_type == SSH_KEX_DH_GROUP1_SHA1 ||
session->next_crypto->kex_type == SSH_KEX_DH_GROUP14_SHA1) {
rc = ssh_buffer_pack(buf,
"BB",
session->next_crypto->e,
session->next_crypto->f);
if (rc != SSH_OK) {
goto error;
}
#ifdef HAVE_ECDH
} else if (session->next_crypto->kex_type == SSH_KEX_ECDH_SHA2_NISTP256) {
if (session->next_crypto->ecdh_client_pubkey == NULL ||
session->next_crypto->ecdh_server_pubkey == NULL) {
SSH_LOG(SSH_LOG_WARNING, "ECDH parameted missing");
goto error;
}
rc = ssh_buffer_pack(buf,
"SS",
session->next_crypto->ecdh_client_pubkey,
session->next_crypto->ecdh_server_pubkey);
if (rc != SSH_OK) {
goto error;
}
#endif
#ifdef HAVE_CURVE25519
} else if (session->next_crypto->kex_type == SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG) {
rc = ssh_buffer_pack(buf,
"dPdP",
CURVE25519_PUBKEY_SIZE,
(size_t)CURVE25519_PUBKEY_SIZE, session->next_crypto->curve25519_client_pubkey,
CURVE25519_PUBKEY_SIZE,
(size_t)CURVE25519_PUBKEY_SIZE, session->next_crypto->curve25519_server_pubkey);
if (rc != SSH_OK) {
goto error;
}
#endif
}
rc = ssh_buffer_pack(buf, "B", session->next_crypto->k);
if (rc != SSH_OK) {
goto error;
}
#ifdef DEBUG_CRYPTO
ssh_print_hexa("hash buffer", ssh_buffer_get_begin(buf), ssh_buffer_get_len(buf));
#endif
switch (session->next_crypto->kex_type) {
case SSH_KEX_DH_GROUP1_SHA1:
case SSH_KEX_DH_GROUP14_SHA1:
session->next_crypto->digest_len = SHA_DIGEST_LENGTH;
session->next_crypto->mac_type = SSH_MAC_SHA1;
session->next_crypto->secret_hash = malloc(session->next_crypto->digest_len);
if (session->next_crypto->secret_hash == NULL) {
ssh_set_error_oom(session);
goto error;
}
sha1(buffer_get_rest(buf), buffer_get_rest_len(buf),
session->next_crypto->secret_hash);
break;
case SSH_KEX_ECDH_SHA2_NISTP256:
case SSH_KEX_CURVE25519_SHA256_LIBSSH_ORG:
session->next_crypto->digest_len = SHA256_DIGEST_LENGTH;
session->next_crypto->mac_type = SSH_MAC_SHA256;
session->next_crypto->secret_hash = malloc(session->next_crypto->digest_len);
if (session->next_crypto->secret_hash == NULL) {
ssh_set_error_oom(session);
goto error;
}
sha256(buffer_get_rest(buf), buffer_get_rest_len(buf),
session->next_crypto->secret_hash);
break;
}
/* During the first kex, secret hash and session ID are equal. However, after
* a key re-exchange, a new secret hash is calculated. This hash will not replace
* but complement existing session id.
*/
if (!session->next_crypto->session_id) {
session->next_crypto->session_id = malloc(session->next_crypto->digest_len);
if (session->next_crypto->session_id == NULL) {
ssh_set_error_oom(session);
goto error;
}
memcpy(session->next_crypto->session_id, session->next_crypto->secret_hash,
session->next_crypto->digest_len);
}
#ifdef DEBUG_CRYPTO
printf("Session hash: \n");
ssh_print_hexa("secret hash", session->next_crypto->secret_hash, session->next_crypto->digest_len);
ssh_print_hexa("session id", session->next_crypto->session_id, session->next_crypto->digest_len);
#endif
rc = SSH_OK;
error:
ssh_buffer_free(buf);
ssh_buffer_free(client_hash);
ssh_buffer_free(server_hash);
session->in_hashbuf = NULL;
session->out_hashbuf = NULL;
ssh_string_free(num);
return rc;
}
/** \internal
* \brief starts a nonblocking flush of the output buffer
*
*/
int ssh_socket_nonblocking_flush(ssh_socket s) {
ssh_session session = s->session;
uint32_t len;
int w;
if (!ssh_socket_is_open(s)) {
session->alive = 0;
if(s->callbacks && s->callbacks->exception){
s->callbacks->exception(
SSH_SOCKET_EXCEPTION_ERROR,
s->last_errno,s->callbacks->userdata);
}else{
ssh_set_error(session, SSH_FATAL,
"Writing packet: error on socket (or connection closed): %s",
strerror(s->last_errno));
}
return SSH_ERROR;
}
len = ssh_buffer_get_len(s->out_buffer);
if (!s->write_wontblock && s->poll_out && len > 0) {
/* force the poll system to catch pollout events */
ssh_poll_add_events(s->poll_out, POLLOUT);
return SSH_AGAIN;
}
if (s->write_wontblock && len > 0) {
w = ssh_socket_unbuffered_write(s, ssh_buffer_get(s->out_buffer), len);
if (w < 0) {
session->alive = 0;
ssh_socket_close(s);
if(s->callbacks && s->callbacks->exception){
s->callbacks->exception(
SSH_SOCKET_EXCEPTION_ERROR,
s->last_errno,s->callbacks->userdata);
}else{
ssh_set_error(session, SSH_FATAL,
"Writing packet: error on socket (or connection closed): %s",
strerror(s->last_errno));
}
return SSH_ERROR;
}
ssh_buffer_pass_bytes(s->out_buffer, w);
if (s->session->socket_counter != NULL) {
s->session->socket_counter->out_bytes += w;
}
}
/* Is there some data pending? */
len = ssh_buffer_get_len(s->out_buffer);
if (s->poll_out && len > 0) {
/* force the poll system to catch pollout events */
ssh_poll_add_events(s->poll_out, POLLOUT);
return SSH_AGAIN;
}
/* all data written */
return SSH_OK;
}
/** @internal
* @brief returns the number of outgoing bytes currently buffered
* @param s the socket
* @returns numbers of bytes buffered, or 0 if the socket isn't connected
*/
int ssh_socket_buffered_write_bytes(ssh_socket s){
if(s==NULL || s->out_buffer == NULL)
return 0;
return ssh_buffer_get_len(s->out_buffer);
}
/**
* @brief SSH poll callback. This callback will be used when an event
* caught on the socket.
*
* @param p Poll object this callback belongs to.
* @param fd The raw socket.
* @param revents The current poll events on the socket.
* @param userdata Userdata to be passed to the callback function,
* in this case the socket object.
*
* @return 0 on success, < 0 when the poll object has been removed
* from its poll context.
*/
int ssh_socket_pollcallback(struct ssh_poll_handle_struct *p, socket_t fd,
int revents, void *v_s) {
ssh_socket s = (ssh_socket)v_s;
char buffer[MAX_BUF_SIZE];
int r;
int err = 0;
socklen_t errlen = sizeof(err);
/* Do not do anything if this socket was already closed */
if (!ssh_socket_is_open(s)) {
return -1;
}
SSH_LOG(SSH_LOG_TRACE, "Poll callback on socket %d (%s%s%s), out buffer %d",fd,
(revents & POLLIN) ? "POLLIN ":"",
(revents & POLLOUT) ? "POLLOUT ":"",
(revents & POLLERR) ? "POLLERR":"",
ssh_buffer_get_len(s->out_buffer));
if (revents & POLLERR || revents & POLLHUP) {
/* Check if we are in a connecting state */
if (s->state == SSH_SOCKET_CONNECTING) {
s->state = SSH_SOCKET_ERROR;
r = getsockopt(fd, SOL_SOCKET, SO_ERROR, (char *)&err, &errlen);
if (r < 0) {
err = errno;
}
s->last_errno = err;
ssh_socket_close(s);
if (s->callbacks && s->callbacks->connected) {
s->callbacks->connected(SSH_SOCKET_CONNECTED_ERROR, err,
s->callbacks->userdata);
}
return -1;
}
/* Then we are in a more standard kind of error */
/* force a read to get an explanation */
revents |= POLLIN;
}
if ((revents & POLLIN) && s->state == SSH_SOCKET_CONNECTED) {
s->read_wontblock = 1;
r = ssh_socket_unbuffered_read(s, buffer, sizeof(buffer));
if (r < 0) {
if (p != NULL) {
ssh_poll_remove_events(p, POLLIN);
}
if (s->callbacks && s->callbacks->exception) {
s->callbacks->exception(SSH_SOCKET_EXCEPTION_ERROR,
s->last_errno, s->callbacks->userdata);
/* p may have been freed, so don't use it
* anymore in this function */
p = NULL;
return -2;
}
}
if (r == 0) {
if (p != NULL) {
ssh_poll_remove_events(p, POLLIN);
}
if (p != NULL) {
ssh_poll_remove_events(p, POLLIN);
}
if (s->callbacks && s->callbacks->exception) {
s->callbacks->exception(SSH_SOCKET_EXCEPTION_EOF,
0, s->callbacks->userdata);
/* p may have been freed, so don't use it
* anymore in this function */
p = NULL;
return -2;
}
}
if (r > 0) {
if (s->session->socket_counter != NULL) {
s->session->socket_counter->in_bytes += r;
}
/* Bufferize the data and then call the callback */
r = ssh_buffer_add_data(s->in_buffer, buffer, r);
if (r < 0) {
return -1;
}
if (s->callbacks && s->callbacks->data) {
do {
r = s->callbacks->data(ssh_buffer_get(s->in_buffer),
ssh_buffer_get_len(s->in_buffer),
s->callbacks->userdata);
ssh_buffer_pass_bytes(s->in_buffer, r);
} while ((r > 0) && (s->state == SSH_SOCKET_CONNECTED));
/* p may have been freed, so don't use it
* anymore in this function */
p = NULL;
}
}
}
#ifdef _WIN32
if (revents & POLLOUT || revents & POLLWRNORM) {
#else
if (revents & POLLOUT) {
#endif
/* First, POLLOUT is a sign we may be connected */
if (s->state == SSH_SOCKET_CONNECTING) {
SSH_LOG(SSH_LOG_PACKET, "Received POLLOUT in connecting state");
s->state = SSH_SOCKET_CONNECTED;
if (p != NULL) {
ssh_poll_set_events(p, POLLOUT | POLLIN);
}
r = ssh_socket_set_blocking(ssh_socket_get_fd_in(s));
if (r < 0) {
return -1;
}
if (s->callbacks && s->callbacks->connected) {
s->callbacks->connected(SSH_SOCKET_CONNECTED_OK, 0,
s->callbacks->userdata);
}
return 0;
}
/* So, we can write data */
s->write_wontblock=1;
if (p != NULL) {
ssh_poll_remove_events(p, POLLOUT);
}
/* If buffered data is pending, write it */
if (ssh_buffer_get_len(s->out_buffer) > 0) {
ssh_socket_nonblocking_flush(s);
} else if (s->callbacks && s->callbacks->controlflow) {
/* Otherwise advertise the upper level that write can be done */
SSH_LOG(SSH_LOG_TRACE,"sending control flow event");
s->callbacks->controlflow(SSH_SOCKET_FLOW_WRITEWONTBLOCK,
s->callbacks->userdata);
}
/* TODO: Find a way to put back POLLOUT when buffering occurs */
}
/* Return -1 if one of the poll handlers disappeared */
return (s->poll_in == NULL || s->poll_out == NULL) ? -1 : 0;
}
/** @internal
* @brief returns the input poll handle corresponding to the socket,
* creates it if it does not exist.
* @returns allocated and initialized ssh_poll_handle object
*/
ssh_poll_handle ssh_socket_get_poll_handle_in(ssh_socket s){
if(s->poll_in)
return s->poll_in;
s->poll_in=ssh_poll_new(s->fd_in,0,ssh_socket_pollcallback,s);
if(s->fd_in == s->fd_out && s->poll_out == NULL)
s->poll_out=s->poll_in;
return s->poll_in;
}
/** @internal
* @brief returns the output poll handle corresponding to the socket,
* creates it if it does not exist.
* @returns allocated and initialized ssh_poll_handle object
*/
ssh_poll_handle ssh_socket_get_poll_handle_out(ssh_socket s){
if(s->poll_out)
return s->poll_out;
s->poll_out=ssh_poll_new(s->fd_out,0,ssh_socket_pollcallback,s);
if(s->fd_in == s->fd_out && s->poll_in == NULL)
s->poll_in=s->poll_out;
return s->poll_out;
}
/** \internal
* \brief Deletes a socket object
*/
void ssh_socket_free(ssh_socket s){
if (s == NULL) {
return;
}
ssh_socket_close(s);
ssh_buffer_free(s->in_buffer);
ssh_buffer_free(s->out_buffer);
SAFE_FREE(s);
}
#ifndef _WIN32
int ssh_socket_unix(ssh_socket s, const char *path) {
struct sockaddr_un sunaddr;
socket_t fd;
sunaddr.sun_family = AF_UNIX;
snprintf(sunaddr.sun_path, sizeof(sunaddr.sun_path), "%s", path);
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd == SSH_INVALID_SOCKET) {
ssh_set_error(s->session, SSH_FATAL,
"Error from socket(AF_UNIX, SOCK_STREAM, 0): %s",
strerror(errno));
return -1;
}
if (fcntl(fd, F_SETFD, 1) == -1) {
ssh_set_error(s->session, SSH_FATAL,
"Error from fcntl(fd, F_SETFD, 1): %s",
strerror(errno));
close(fd);
return -1;
}
if (connect(fd, (struct sockaddr *) &sunaddr,
sizeof(sunaddr)) < 0) {
ssh_set_error(s->session, SSH_FATAL, "Error from connect(): %s",
strerror(errno));
close(fd);
return -1;
}
ssh_socket_set_fd(s,fd);
return 0;
}
#endif
/** \internal
* \brief closes a socket
*/
void ssh_socket_close(ssh_socket s){
if (ssh_socket_is_open(s)) {
#ifdef _WIN32
CLOSE_SOCKET(s->fd_in);
/* fd_in = fd_out under win32 */
s->last_errno = WSAGetLastError();
#else
if (s->fd_out != s->fd_in && s->fd_out != -1) {
CLOSE_SOCKET(s->fd_out);
}
CLOSE_SOCKET(s->fd_in);
s->last_errno = errno;
#endif
}
if(s->poll_in != NULL){
if(s->poll_out == s->poll_in)
s->poll_out = NULL;
ssh_poll_free(s->poll_in);
s->poll_in=NULL;
}
if(s->poll_out != NULL){
ssh_poll_free(s->poll_out);
s->poll_out=NULL;
}
s->state = SSH_SOCKET_CLOSED;
}
/**
* @internal
* @brief sets the file descriptor of the socket.
* @param[out] s ssh_socket to update
* @param[in] fd file descriptor to set
* @warning this function updates boths the input and output
* file descriptors
*/
void ssh_socket_set_fd(ssh_socket s, socket_t fd) {
s->fd_in = s->fd_out = fd;
if (s->poll_in) {
ssh_poll_set_fd(s->poll_in,fd);
} else {
s->state = SSH_SOCKET_CONNECTING;
/* POLLOUT is the event to wait for in a nonblocking connect */
ssh_poll_set_events(ssh_socket_get_poll_handle_in(s), POLLOUT);
#ifdef _WIN32
ssh_poll_add_events(ssh_socket_get_poll_handle_in(s), POLLWRNORM);
#endif
}
}
static int packet_send2(ssh_session session) {
unsigned int blocksize = (session->current_crypto ?
session->current_crypto->out_cipher->blocksize : 8);
enum ssh_hmac_e hmac_type = (session->current_crypto ?
session->current_crypto->out_hmac : session->next_crypto->out_hmac);
uint32_t currentlen = ssh_buffer_get_len(session->out_buffer);
unsigned char *hmac = NULL;
char padstring[32] = { 0 };
int rc = SSH_ERROR;
uint32_t finallen,payloadsize,compsize;
uint8_t padding;
uint8_t header[sizeof(padding) + sizeof(finallen)] = { 0 };
payloadsize = currentlen;
#ifdef WITH_ZLIB
if (session->current_crypto
&& session->current_crypto->do_compress_out
&& ssh_buffer_get_len(session->out_buffer)) {
if (compress_buffer(session,session->out_buffer) < 0) {
goto error;
}
currentlen = ssh_buffer_get_len(session->out_buffer);
}
#endif /* WITH_ZLIB */
compsize = currentlen;
padding = (blocksize - ((currentlen +5) % blocksize));
if(padding < 4) {
padding += blocksize;
}
if (session->current_crypto) {
ssh_get_random(padstring, padding, 0);
}
finallen = htonl(currentlen + padding + 1);
memcpy(&header[0], &finallen, sizeof(finallen));
header[sizeof(finallen)] = padding;
rc = ssh_buffer_prepend_data(session->out_buffer, &header, sizeof(header));
if (rc < 0) {
goto error;
}
rc = ssh_buffer_add_data(session->out_buffer, padstring, padding);
if (rc < 0) {
goto error;
}
#ifdef WITH_PCAP
if(session->pcap_ctx){
ssh_pcap_context_write(session->pcap_ctx,SSH_PCAP_DIR_OUT,
ssh_buffer_get(session->out_buffer),ssh_buffer_get_len(session->out_buffer)
,ssh_buffer_get_len(session->out_buffer));
}
#endif
hmac = ssh_packet_encrypt(session, ssh_buffer_get(session->out_buffer),
ssh_buffer_get_len(session->out_buffer));
if (hmac) {
rc = ssh_buffer_add_data(session->out_buffer, hmac, hmac_digest_len(hmac_type));
if (rc < 0) {
goto error;
}
}
rc = ssh_packet_write(session);
session->send_seq++;
if (session->raw_counter != NULL) {
session->raw_counter->out_bytes += payloadsize;
session->raw_counter->out_packets++;
}
SSH_LOG(SSH_LOG_PACKET,
"packet: wrote [len=%d,padding=%hhd,comp=%d,payload=%d]",
ntohl(finallen), padding, compsize, payloadsize);
if (ssh_buffer_reinit(session->out_buffer) < 0) {
rc = SSH_ERROR;
}
error:
return rc; /* SSH_OK, AGAIN or ERROR */
}
int make_sessionid(ssh_session session) {
SHACTX ctx;
ssh_string num = NULL;
ssh_string str = NULL;
ssh_buffer server_hash = NULL;
ssh_buffer client_hash = NULL;
ssh_buffer buf = NULL;
uint32_t len;
int rc = SSH_ERROR;
enter_function();
ctx = sha1_init();
if (ctx == NULL) {
return rc;
}
buf = ssh_buffer_new();
if (buf == NULL) {
return rc;
}
str = ssh_string_from_char(session->clientbanner);
if (str == NULL) {
goto error;
}
if (buffer_add_ssh_string(buf, str) < 0) {
goto error;
}
ssh_string_free(str);
str = ssh_string_from_char(session->serverbanner);
if (str == NULL) {
goto error;
}
if (buffer_add_ssh_string(buf, str) < 0) {
goto error;
}
if (session->client) {
server_hash = session->in_hashbuf;
client_hash = session->out_hashbuf;
} else {
server_hash = session->out_hashbuf;
client_hash = session->in_hashbuf;
}
if (buffer_add_u32(server_hash, 0) < 0) {
goto error;
}
if (buffer_add_u8(server_hash, 0) < 0) {
goto error;
}
if (buffer_add_u32(client_hash, 0) < 0) {
goto error;
}
if (buffer_add_u8(client_hash, 0) < 0) {
goto error;
}
len = ntohl(buffer_get_rest_len(client_hash));
if (buffer_add_u32(buf,len) < 0) {
goto error;
}
if (buffer_add_data(buf, buffer_get_rest(client_hash),
buffer_get_rest_len(client_hash)) < 0) {
goto error;
}
len = ntohl(buffer_get_rest_len(server_hash));
if (buffer_add_u32(buf, len) < 0) {
goto error;
}
if (buffer_add_data(buf, buffer_get_rest(server_hash),
buffer_get_rest_len(server_hash)) < 0) {
goto error;
}
len = ssh_string_len(session->next_crypto->server_pubkey) + 4;
if (buffer_add_data(buf, session->next_crypto->server_pubkey, len) < 0) {
goto error;
}
num = make_bignum_string(session->next_crypto->e);
if (num == NULL) {
goto error;
}
len = ssh_string_len(num) + 4;
if (buffer_add_data(buf, num, len) < 0) {
goto error;
}
ssh_string_free(num);
num = make_bignum_string(session->next_crypto->f);
if (num == NULL) {
goto error;
}
len = ssh_string_len(num) + 4;
if (buffer_add_data(buf, num, len) < 0) {
goto error;
}
ssh_string_free(num);
num = make_bignum_string(session->next_crypto->k);
if (num == NULL) {
goto error;
}
len = ssh_string_len(num) + 4;
if (buffer_add_data(buf, num, len) < 0) {
goto error;
}
#ifdef DEBUG_CRYPTO
ssh_print_hexa("hash buffer", ssh_buffer_get_begin(buf), ssh_buffer_get_len(buf));
#endif
sha1_update(ctx, buffer_get_rest(buf), buffer_get_rest_len(buf));
sha1_final(session->next_crypto->session_id, ctx);
#ifdef DEBUG_CRYPTO
printf("Session hash: ");
ssh_print_hexa("session id", session->next_crypto->session_id, SHA_DIGEST_LEN);
#endif
rc = SSH_OK;
error:
ssh_buffer_free(buf);
ssh_buffer_free(client_hash);
ssh_buffer_free(server_hash);
session->in_hashbuf = NULL;
session->out_hashbuf = NULL;
ssh_string_free(str);
ssh_string_free(num);
leave_function();
return rc;
}
static int packet_send2(ssh_session session) {
unsigned int blocksize = (session->current_crypto ?
session->current_crypto->out_cipher->blocksize : 8);
unsigned int lenfield_blocksize = (session->current_crypto ?
session->current_crypto->out_cipher->lenfield_blocksize : 0);
enum ssh_hmac_e hmac_type = (session->current_crypto ?
session->current_crypto->out_hmac : session->next_crypto->out_hmac);
uint32_t currentlen = ssh_buffer_get_len(session->out_buffer);
unsigned char *hmac = NULL;
char padstring[32] = { 0 };
int rc = SSH_ERROR;
uint32_t finallen,payloadsize,compsize;
uint8_t padding;
ssh_buffer header_buffer = ssh_buffer_new();
payloadsize = currentlen;
#ifdef WITH_ZLIB
if (session->current_crypto
&& session->current_crypto->do_compress_out
&& ssh_buffer_get_len(session->out_buffer)) {
if (compress_buffer(session,session->out_buffer) < 0) {
goto error;
}
currentlen = ssh_buffer_get_len(session->out_buffer);
}
#endif /* WITH_ZLIB */
compsize = currentlen;
/* compressed payload + packet len (4) + padding len (1) */
/* totallen - lenfield_blocksize must be equal to 0 (mod blocksize) */
padding = (blocksize - ((blocksize - lenfield_blocksize + currentlen + 5) % blocksize));
if(padding < 4) {
padding += blocksize;
}
if (session->current_crypto != NULL) {
int ok;
ok = ssh_get_random(padstring, padding, 0);
if (!ok) {
ssh_set_error(session, SSH_FATAL, "PRNG error");
goto error;
}
}
if (header_buffer == NULL){
ssh_set_error_oom(session);
goto error;
}
finallen = currentlen + padding + 1;
rc = ssh_buffer_pack(header_buffer, "db", finallen, padding);
if (rc == SSH_ERROR){
goto error;
}
rc = ssh_buffer_prepend_data(session->out_buffer,
ssh_buffer_get(header_buffer),
ssh_buffer_get_len(header_buffer));
if (rc < 0) {
goto error;
}
rc = ssh_buffer_add_data(session->out_buffer, padstring, padding);
if (rc < 0) {
goto error;
}
#ifdef WITH_PCAP
if (session->pcap_ctx) {
ssh_pcap_context_write(session->pcap_ctx,
SSH_PCAP_DIR_OUT,
ssh_buffer_get(session->out_buffer),
ssh_buffer_get_len(session->out_buffer),
ssh_buffer_get_len(session->out_buffer));
}
#endif
hmac = ssh_packet_encrypt(session, ssh_buffer_get(session->out_buffer),
ssh_buffer_get_len(session->out_buffer));
if (hmac) {
rc = ssh_buffer_add_data(session->out_buffer, hmac, hmac_digest_len(hmac_type));
if (rc < 0) {
goto error;
}
}
rc = ssh_packet_write(session);
session->send_seq++;
if (session->raw_counter != NULL) {
session->raw_counter->out_bytes += payloadsize;
session->raw_counter->out_packets++;
}
SSH_LOG(SSH_LOG_PACKET,
"packet: wrote [len=%d,padding=%hhd,comp=%d,payload=%d]",
finallen, padding, compsize, payloadsize);
if (ssh_buffer_reinit(session->out_buffer) < 0) {
rc = SSH_ERROR;
}
error:
if (header_buffer != NULL) {
ssh_buffer_free(header_buffer);
}
return rc; /* SSH_OK, AGAIN or ERROR */
}
/** @internal
* @handles a data received event. It then calls the handlers for the different packet types
* or and exception handler callback.
* @param user pointer to current ssh_session
* @param data pointer to the data received
* @len length of data received. It might not be enough for a complete packet
* @returns number of bytes read and processed.
*/
int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user)
{
ssh_session session= (ssh_session) user;
unsigned int blocksize = (session->current_crypto ?
session->current_crypto->in_cipher->blocksize : 8);
unsigned int lenfield_blocksize = (session->current_crypto ?
session->current_crypto->in_cipher->lenfield_blocksize : 8);
size_t current_macsize = 0;
uint8_t *ptr = NULL;
int to_be_read;
int rc;
uint8_t *cleartext_packet = NULL;
uint8_t *packet_second_block = NULL;
uint8_t *mac = NULL;
size_t packet_remaining;
uint32_t packet_len, compsize, payloadsize;
uint8_t padding;
size_t processed = 0; /* number of byte processed from the callback */
if(session->current_crypto != NULL) {
current_macsize = hmac_digest_len(session->current_crypto->in_hmac);
}
if (lenfield_blocksize == 0) {
lenfield_blocksize = blocksize;
}
if (data == NULL) {
goto error;
}
if (session->session_state == SSH_SESSION_STATE_ERROR) {
goto error;
}
#ifdef DEBUG_PACKET
SSH_LOG(SSH_LOG_PACKET,
"rcv packet cb (len=%zu, state=%s)",
receivedlen,
session->packet_state == PACKET_STATE_INIT ?
"INIT" :
session->packet_state == PACKET_STATE_SIZEREAD ?
"SIZE_READ" :
session->packet_state == PACKET_STATE_PROCESSING ?
"PROCESSING" : "unknown");
#endif
switch(session->packet_state) {
case PACKET_STATE_INIT:
if (receivedlen < lenfield_blocksize) {
/*
* We didn't receive enough data to read at least one
* block size, give up
*/
#ifdef DEBUG_PACKET
SSH_LOG(SSH_LOG_PACKET,
"Waiting for more data (%zu < %u)",
receivedlen,
lenfield_blocksize);
#endif
return 0;
}
memset(&session->in_packet, 0, sizeof(PACKET));
if (session->in_buffer) {
rc = ssh_buffer_reinit(session->in_buffer);
if (rc < 0) {
goto error;
}
} else {
session->in_buffer = ssh_buffer_new();
if (session->in_buffer == NULL) {
goto error;
}
}
ptr = ssh_buffer_allocate(session->in_buffer, lenfield_blocksize);
if (ptr == NULL) {
goto error;
}
processed += lenfield_blocksize;
packet_len = ssh_packet_decrypt_len(session, ptr, (uint8_t *)data);
if (packet_len > MAX_PACKET_LEN) {
ssh_set_error(session,
SSH_FATAL,
"read_packet(): Packet len too high(%u %.4x)",
packet_len, packet_len);
goto error;
}
to_be_read = packet_len - lenfield_blocksize + sizeof(uint32_t);
if (to_be_read < 0) {
/* remote sshd sends invalid sizes? */
ssh_set_error(session,
SSH_FATAL,
"Given numbers of bytes left to be read < 0 (%d)!",
to_be_read);
goto error;
}
session->in_packet.len = packet_len;
session->packet_state = PACKET_STATE_SIZEREAD;
FALL_THROUGH;
case PACKET_STATE_SIZEREAD:
packet_len = session->in_packet.len;
processed = lenfield_blocksize;
to_be_read = packet_len + sizeof(uint32_t) + current_macsize;
/* if to_be_read is zero, the whole packet was blocksize bytes. */
if (to_be_read != 0) {
if (receivedlen < (unsigned int)to_be_read) {
/* give up, not enough data in buffer */
SSH_LOG(SSH_LOG_PACKET,
"packet: partial packet (read len) "
"[len=%d, receivedlen=%d, to_be_read=%d]",
packet_len,
(int)receivedlen,
to_be_read);
return 0;
}
packet_second_block = (uint8_t*)data + lenfield_blocksize;
processed = to_be_read - current_macsize;
}
/* remaining encrypted bytes from the packet, MAC not included */
packet_remaining =
packet_len - (lenfield_blocksize - sizeof(uint32_t));
cleartext_packet = ssh_buffer_allocate(session->in_buffer,
packet_remaining);
if (session->current_crypto) {
/*
* Decrypt the rest of the packet (lenfield_blocksize bytes already
* have been decrypted)
*/
if (packet_remaining > 0) {
rc = ssh_packet_decrypt(session,
cleartext_packet,
(uint8_t *)data,
lenfield_blocksize,
processed - lenfield_blocksize);
if (rc < 0) {
ssh_set_error(session, SSH_FATAL, "Decryption error");
goto error;
}
}
mac = packet_second_block + packet_remaining;
rc = ssh_packet_hmac_verify(session, session->in_buffer, mac, session->current_crypto->in_hmac);
if (rc < 0) {
ssh_set_error(session, SSH_FATAL, "HMAC error");
goto error;
}
processed += current_macsize;
} else {
memcpy(cleartext_packet, packet_second_block, packet_remaining);
}
/* skip the size field which has been processed before */
ssh_buffer_pass_bytes(session->in_buffer, sizeof(uint32_t));
rc = ssh_buffer_get_u8(session->in_buffer, &padding);
if (rc == 0) {
ssh_set_error(session,
SSH_FATAL,
"Packet too short to read padding");
goto error;
}
if (padding > ssh_buffer_get_len(session->in_buffer)) {
ssh_set_error(session,
SSH_FATAL,
"Invalid padding: %d (%d left)",
padding,
ssh_buffer_get_len(session->in_buffer));
goto error;
}
ssh_buffer_pass_bytes_end(session->in_buffer, padding);
compsize = ssh_buffer_get_len(session->in_buffer);
#ifdef WITH_ZLIB
if (session->current_crypto
&& session->current_crypto->do_compress_in
&& ssh_buffer_get_len(session->in_buffer) > 0) {
rc = decompress_buffer(session, session->in_buffer,MAX_PACKET_LEN);
if (rc < 0) {
goto error;
}
}
#endif /* WITH_ZLIB */
payloadsize = ssh_buffer_get_len(session->in_buffer);
session->recv_seq++;
if (session->raw_counter != NULL) {
session->raw_counter->in_bytes += payloadsize;
session->raw_counter->in_packets++;
}
/*
* We don't want to rewrite a new packet while still executing the
* packet callbacks
*/
session->packet_state = PACKET_STATE_PROCESSING;
ssh_packet_parse_type(session);
SSH_LOG(SSH_LOG_PACKET,
"packet: read type %hhd [len=%d,padding=%hhd,comp=%d,payload=%d]",
session->in_packet.type, packet_len, padding, compsize, payloadsize);
/* Execute callbacks */
ssh_packet_process(session, session->in_packet.type);
session->packet_state = PACKET_STATE_INIT;
if (processed < receivedlen) {
/* Handle a potential packet left in socket buffer */
SSH_LOG(SSH_LOG_PACKET,
"Processing %" PRIdS " bytes left in socket buffer",
receivedlen-processed);
ptr = ((uint8_t*)data) + processed;
rc = ssh_packet_socket_callback(ptr, receivedlen - processed,user);
processed += rc;
}
return processed;
case PACKET_STATE_PROCESSING:
SSH_LOG(SSH_LOG_PACKET, "Nested packet processing. Delaying.");
return 0;
}
ssh_set_error(session,
SSH_FATAL,
"Invalid state into packet_read2(): %d",
session->packet_state);
error:
session->session_state= SSH_SESSION_STATE_ERROR;
SSH_LOG(SSH_LOG_PACKET,"Packet: processed %" PRIdS " bytes", processed);
return processed;
}
/*
* This function signs the session id as a string then
* the content of sigbuf */
ssh_string ssh_pki_do_sign(ssh_session session,
ssh_buffer sigbuf,
const ssh_key privkey) {
struct ssh_crypto_struct *crypto =
session->current_crypto ? session->current_crypto :
session->next_crypto;
ssh_signature sig = NULL;
ssh_string sig_blob;
ssh_string session_id;
int rc;
if (privkey == NULL || !ssh_key_is_private(privkey)) {
return NULL;
}
session_id = ssh_string_new(crypto->digest_len);
if (session_id == NULL) {
return NULL;
}
ssh_string_fill(session_id, crypto->session_id, crypto->digest_len);
if (privkey->type == SSH_KEYTYPE_ECDSA) {
#ifdef HAVE_ECC
unsigned char ehash[EVP_DIGEST_LEN] = {0};
uint32_t elen;
EVPCTX ctx;
ctx = evp_init(privkey->ecdsa_nid);
if (ctx == NULL) {
ssh_string_free(session_id);
return NULL;
}
evp_update(ctx, session_id, ssh_string_len(session_id) + 4);
evp_update(ctx, ssh_buffer_get(sigbuf), ssh_buffer_get_len(sigbuf));
evp_final(ctx, ehash, &elen);
#ifdef DEBUG_CRYPTO
ssh_print_hexa("Hash being signed", ehash, elen);
#endif
sig = pki_do_sign(privkey, ehash, elen);
#endif
} else if (privkey->type == SSH_KEYTYPE_ED25519){
ssh_buffer buf;
buf = ssh_buffer_new();
if (buf == NULL) {
ssh_string_free(session_id);
return NULL;
}
ssh_buffer_set_secure(buf);
rc = ssh_buffer_pack(buf,
"SP",
session_id,
ssh_buffer_get_len(sigbuf), ssh_buffer_get(sigbuf));
if (rc != SSH_OK) {
ssh_string_free(session_id);
ssh_buffer_free(buf);
return NULL;
}
sig = pki_do_sign(privkey,
ssh_buffer_get(buf),
ssh_buffer_get_len(buf));
ssh_buffer_free(buf);
} else {
unsigned char hash[SHA_DIGEST_LEN] = {0};
SHACTX ctx;
ctx = sha1_init();
if (ctx == NULL) {
ssh_string_free(session_id);
return NULL;
}
sha1_update(ctx, session_id, ssh_string_len(session_id) + 4);
sha1_update(ctx, ssh_buffer_get(sigbuf), ssh_buffer_get_len(sigbuf));
sha1_final(hash, ctx);
#ifdef DEBUG_CRYPTO
ssh_print_hexa("Hash being signed", hash, SHA_DIGEST_LEN);
#endif
sig = pki_do_sign(privkey, hash, SHA_DIGEST_LEN);
}
ssh_string_free(session_id);
if (sig == NULL) {
return NULL;
}
rc = ssh_pki_export_signature_blob(sig, &sig_blob);
ssh_signature_free(sig);
if (rc < 0) {
return NULL;
}
return sig_blob;
}
/** @internal
* @handles a data received event. It then calls the handlers for the different packet types
* or and exception handler callback.
* @param user pointer to current ssh_session
* @param data pointer to the data received
* @len length of data received. It might not be enough for a complete packet
* @returns number of bytes read and processed.
*/
int ssh_packet_socket_callback(const void *data, size_t receivedlen, void *user){
ssh_session session=(ssh_session) user;
unsigned int blocksize = (session->current_crypto ?
session->current_crypto->in_cipher->blocksize : 8);
int current_macsize = session->current_crypto ? macsize : 0;
unsigned char mac[30] = {0};
char buffer[16] = {0};
void *packet=NULL;
int to_be_read;
int rc;
uint32_t len;
uint8_t padding;
size_t processed=0; /* number of byte processed from the callback */
enter_function();
switch(session->packet_state) {
case PACKET_STATE_INIT:
if(receivedlen < blocksize){
/* We didn't receive enough data to read at least one block size, give up */
leave_function();
return 0;
}
memset(&session->in_packet, 0, sizeof(PACKET));
if (session->in_buffer) {
if (buffer_reinit(session->in_buffer) < 0) {
goto error;
}
} else {
session->in_buffer = ssh_buffer_new();
if (session->in_buffer == NULL) {
goto error;
}
}
memcpy(buffer,data,blocksize);
processed += blocksize;
len = packet_decrypt_len(session, buffer);
if (buffer_add_data(session->in_buffer, buffer, blocksize) < 0) {
goto error;
}
if(len > MAX_PACKET_LEN) {
ssh_set_error(session, SSH_FATAL,
"read_packet(): Packet len too high(%u %.4x)", len, len);
goto error;
}
to_be_read = len - blocksize + sizeof(uint32_t);
if (to_be_read < 0) {
/* remote sshd sends invalid sizes? */
ssh_set_error(session, SSH_FATAL,
"given numbers of bytes left to be read < 0 (%d)!", to_be_read);
goto error;
}
/* saves the status of the current operations */
session->in_packet.len = len;
session->packet_state = PACKET_STATE_SIZEREAD;
case PACKET_STATE_SIZEREAD:
len = session->in_packet.len;
to_be_read = len - blocksize + sizeof(uint32_t) + current_macsize;
/* if to_be_read is zero, the whole packet was blocksize bytes. */
if (to_be_read != 0) {
if(receivedlen - processed < (unsigned int)to_be_read){
/* give up, not enough data in buffer */
return processed;
}
packet = (unsigned char *)data + processed;
// ssh_socket_read(session->socket,packet,to_be_read-current_macsize);
ssh_log(session,SSH_LOG_PACKET,"Read a %d bytes packet",len);
if (buffer_add_data(session->in_buffer, packet,
to_be_read - current_macsize) < 0) {
goto error;
}
processed += to_be_read - current_macsize;
}
if (session->current_crypto) {
/*
* decrypt the rest of the packet (blocksize bytes already
* have been decrypted)
*/
if (packet_decrypt(session,
((uint8_t*)buffer_get_rest(session->in_buffer) + blocksize),
buffer_get_rest_len(session->in_buffer) - blocksize) < 0) {
ssh_set_error(session, SSH_FATAL, "Decrypt error");
goto error;
}
/* copy the last part from the incoming buffer */
memcpy(mac,(unsigned char *)packet + to_be_read - current_macsize, macsize);
if (packet_hmac_verify(session, session->in_buffer, mac) < 0) {
ssh_set_error(session, SSH_FATAL, "HMAC error");
goto error;
}
processed += current_macsize;
}
/* skip the size field which has been processed before */
buffer_pass_bytes(session->in_buffer, sizeof(uint32_t));
if (buffer_get_u8(session->in_buffer, &padding) == 0) {
ssh_set_error(session, SSH_FATAL, "Packet too short to read padding");
goto error;
}
ssh_log(session, SSH_LOG_PACKET,
"%hhd bytes padding, %d bytes left in buffer",
padding, buffer_get_rest_len(session->in_buffer));
if (padding > buffer_get_rest_len(session->in_buffer)) {
ssh_set_error(session, SSH_FATAL,
"Invalid padding: %d (%d resting)",
padding,
buffer_get_rest_len(session->in_buffer));
#ifdef DEBUG_CRYPTO
ssh_print_hexa("incrimined packet",
ssh_buffer_get_begin(session->in_buffer),
ssh_buffer_get_len(session->in_buffer));
#endif
goto error;
}
buffer_pass_bytes_end(session->in_buffer, padding);
ssh_log(session, SSH_LOG_PACKET,
"After padding, %d bytes left in buffer",
buffer_get_rest_len(session->in_buffer));
#if defined(HAVE_LIBZ) && defined(WITH_LIBZ)
if (session->current_crypto
&& session->current_crypto->do_compress_in
&& buffer_get_rest_len(session->in_buffer)) {
ssh_log(session, SSH_LOG_PACKET, "Decompressing in_buffer ...");
if (decompress_buffer(session, session->in_buffer,MAX_PACKET_LEN) < 0) {
goto error;
}
}
#endif
session->recv_seq++;
/* We don't want to rewrite a new packet while still executing the packet callbacks */
session->packet_state = PACKET_STATE_PROCESSING;
ssh_packet_parse_type(session);
/* execute callbacks */
ssh_packet_process(session, session->in_packet.type);
session->packet_state = PACKET_STATE_INIT;
if(processed < receivedlen){
/* Handle a potential packet left in socket buffer */
ssh_log(session,SSH_LOG_PACKET,"Processing %" PRIdS " bytes left in socket buffer",
receivedlen-processed);
rc = ssh_packet_socket_callback((char *)data + processed,
receivedlen - processed,user);
processed += rc;
}
leave_function();
return processed;
case PACKET_STATE_PROCESSING:
ssh_log(session, SSH_LOG_RARE, "Nested packet processing. Delaying.");
return 0;
}
ssh_set_error(session, SSH_FATAL,
"Invalid state into packet_read2(): %d",
session->packet_state);
error:
leave_function();
return processed;
}
