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SSH2 MACs now use dynamically allocated contexts.

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[originally from svn r2131]
This commit is contained in:
Simon Tatham
2002-10-25 12:51:28 +00:00
parent 9848062b86
commit 8f91f07599
4 changed files with 108 additions and 85 deletions
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39
ssh.c
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@ -371,19 +371,28 @@ const static struct ssh_kex *kex_algs[] = {
const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
static void nullmac_key(unsigned char *key)
static void *nullmac_make_context(void)
{
return NULL;
}
static void nullmac_free_context(void *handle)
{
}
static void nullmac_generate(unsigned char *blk, int len,
static void nullmac_key(void *handle, unsigned char *key)
{
}
static void nullmac_generate(void *handle, unsigned char *blk, int len,
unsigned long seq)
{
}
static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
static int nullmac_verify(void *handle, unsigned char *blk, int len,
unsigned long seq)
{
return 1;
}
const static struct ssh_mac ssh_mac_none = {
nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
nullmac_make_context, nullmac_free_context, nullmac_key,
nullmac_generate, nullmac_verify, "none", 0
};
const static struct ssh_mac *macs[] = {
&ssh_sha1, &ssh_md5, &ssh_mac_none
@ -554,6 +563,7 @@ struct ssh_tag {
const struct ssh2_cipher *cscipher, *sccipher;
void *cs_cipher_ctx, *sc_cipher_ctx;
const struct ssh_mac *csmac, *scmac;
void *cs_mac_ctx, *sc_mac_ctx;
const struct ssh_compress *cscomp, *sccomp;
const struct ssh_kex *kex;
const struct ssh_signkey *hostkey;
@ -979,7 +989,7 @@ static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
* Check the MAC.
*/
if (ssh->scmac
&& !ssh->scmac->verify(ssh->pktin.data, st->len + 4,
&& !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
st->incoming_sequence)) {
bombout(("Incorrect MAC received on packet"));
crReturn(0);
@ -1468,7 +1478,8 @@ static int ssh2_pkt_construct(Ssh ssh)
ssh->pktout.data[ssh->pktout.length + i] = random_byte();
PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
if (ssh->csmac)
ssh->csmac->generate(ssh->pktout.data, ssh->pktout.length + padding,
ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
ssh->pktout.length + padding,
ssh->v2_outgoing_sequence);
ssh->v2_outgoing_sequence++; /* whether or not we MACed */
@ -4031,12 +4042,22 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
ssh->cscipher->free_context(ssh->cs_cipher_ctx);
ssh->cscipher = s->cscipher_tobe;
ssh->cs_cipher_ctx = ssh->cscipher->make_context();
if (ssh->sc_cipher_ctx)
ssh->sccipher->free_context(ssh->sc_cipher_ctx);
ssh->sccipher = s->sccipher_tobe;
ssh->sc_cipher_ctx = ssh->sccipher->make_context();
if (ssh->cs_mac_ctx)
ssh->csmac->free_context(ssh->cs_mac_ctx);
ssh->csmac = s->csmac_tobe;
ssh->cs_mac_ctx = ssh->csmac->make_context();
if (ssh->sc_mac_ctx)
ssh->scmac->free_context(ssh->sc_mac_ctx);
ssh->scmac = s->scmac_tobe;
ssh->sc_mac_ctx = ssh->scmac->make_context();
ssh->cscomp = s->cscomp_tobe;
ssh->sccomp = s->sccomp_tobe;
ssh->cscomp->compress_init();
@ -4059,9 +4080,9 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
ssh->csmac->setcskey(keyspace);
ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
ssh->scmac->setsckey(keyspace);
ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
}
{
char buf[256];
@ -5785,7 +5806,9 @@ static char *ssh_init(void *frontend_handle, void **backend_handle,
ssh->sccipher = NULL;
ssh->sc_cipher_ctx = NULL;
ssh->csmac = NULL;
ssh->sc_mac_ctx = NULL;
ssh->scmac = NULL;
ssh->sc_mac_ctx = NULL;
ssh->cscomp = NULL;
ssh->sccomp = NULL;
ssh->kex = NULL;