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packet: Reformat packet_send2()

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Signed-off-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
This commit is contained in:
Andreas Schneider
2018-10-07 14:23:57 +02:00
parent 3245b50795
commit 422376efd4
1 changed files with 107 additions and 92 deletions
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199
src/packet.c
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@@ -551,106 +551,121 @@ static int ssh_packet_write(ssh_session session) {
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();
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;
uint8_t padstring[32] = { 0 };
uint8_t padding;
uint32_t finallen, payloadsize, compsize;
ssh_buffer header_buffer = ssh_buffer_new();
int rc = SSH_ERROR;
payloadsize = currentlen;
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;
if (session->current_crypto != NULL &&
session->current_crypto->do_compress_out &&
ssh_buffer_get_len(session->out_buffer) > 0) {
rc = compress_buffer(session,session->out_buffer);
if (rc < 0) {
goto error;
}
currentlen = ssh_buffer_get_len(session->out_buffer);
}
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;
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;
}
}
rc = ssh_packet_write(session);
session->send_seq++;
if (session->raw_counter != NULL) {
session->raw_counter->out_bytes += payloadsize;
session->raw_counter->out_packets++;
}
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 != NULL) {
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 != NULL) {
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);
rc = ssh_buffer_reinit(session->out_buffer);
if (rc < 0) {
rc = SSH_ERROR;
}
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 */
if (header_buffer != NULL) {
ssh_buffer_free(header_buffer);
}
return rc; /* SSH_OK, AGAIN or ERROR */
}