/*
* Add/remove an token-based identity from the authentication server.
* This call is intended only for use by ssh-add(1) and like applications.
*/
int
ssh_update_card(int sock, int add, const char *reader_id, const char *pin,
u_int life, u_int confirm)
{
struct sshbuf *msg;
int r, constrained = (life || confirm);
u_char type;
if (add) {
type = constrained ?
SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED :
SSH_AGENTC_ADD_SMARTCARD_KEY;
} else
type = SSH_AGENTC_REMOVE_SMARTCARD_KEY;
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_put_u8(msg, type)) != 0 ||
(r = sshbuf_put_cstring(msg, reader_id)) != 0 ||
(r = sshbuf_put_cstring(msg, pin)) != 0)
goto out;
if (constrained &&
(r = encode_constraints(msg, life, confirm)) != 0)
goto out;
if ((r = ssh_request_reply(sock, msg, msg)) != 0)
goto out;
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
r = decode_reply(type);
out:
sshbuf_free(msg);
return r;
}
static int
recv_msg(struct sshbuf *m)
{
u_int l, len;
u_char c, buf[1024];
int r;
if ((len = atomicio(read, fd, buf, 4)) != 4) {
error("read from helper failed: %u", len);
return (0); /* XXX */
}
len = PEEK_U32(buf);
if (len > 256 * 1024)
fatal("response too long: %u", len);
/* read len bytes into m */
sshbuf_reset(m);
while (len > 0) {
l = len;
if (l > sizeof(buf))
l = sizeof(buf);
if (atomicio(read, fd, buf, l) != l) {
error("response from helper failed.");
return (0); /* XXX */
}
if ((r = sshbuf_put(m, buf, l)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
len -= l;
}
if ((r = sshbuf_get_u8(m, &c)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
return c;
}
int
sshkey_xmss_deserialize_state_opt(struct sshkey *k, struct sshbuf *b)
{
enum sshkey_serialize_rep opts;
u_char have_state;
int r;
if ((r = sshbuf_get_u8(b, &have_state)) != 0)
return r;
opts = have_state;
switch (opts) {
case SSHKEY_SERIALIZE_DEFAULT:
r = 0;
break;
case SSHKEY_SERIALIZE_STATE:
if ((r = sshkey_xmss_deserialize_state(k, b)) != 0)
return r;
break;
case SSHKEY_SERIALIZE_FULL:
if ((r = sshkey_xmss_deserialize_enc_key(k, b)) != 0 ||
(r = sshkey_xmss_deserialize_state(k, b)) != 0)
return r;
break;
default:
r = SSH_ERR_INVALID_FORMAT;
break;
}
return r;
}
/*
* Parse the public, unencrypted portion of a RSA1 key.
*/
int
sshkey_parse_public_rsa1(struct sshbuf *blob,
struct sshkey **keyp, char **commentp)
{
int r;
struct sshkey *pub = NULL;
struct sshbuf *copy = NULL;
*keyp = NULL;
if (commentp != NULL)
*commentp = NULL;
/* Check that it is at least big enough to contain the ID string. */
if (sshbuf_len(blob) < sizeof(authfile_id_string))
return SSH_ERR_INVALID_FORMAT;
/*
* Make sure it begins with the id string. Consume the id string
* from the buffer.
*/
if (memcmp(sshbuf_ptr(blob), authfile_id_string,
sizeof(authfile_id_string)) != 0)
return SSH_ERR_INVALID_FORMAT;
/* Make a working copy of the keyblob and skip past the magic */
if ((copy = sshbuf_fromb(blob)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_consume(copy, sizeof(authfile_id_string))) != 0)
goto out;
/* Skip cipher type, reserved data and key bits. */
if ((r = sshbuf_get_u8(copy, NULL)) != 0 || /* cipher type */
(r = sshbuf_get_u32(copy, NULL)) != 0 || /* reserved */
(r = sshbuf_get_u32(copy, NULL)) != 0) /* key bits */
goto out;
/* Read the public key from the buffer. */
if ((pub = sshkey_new(KEY_RSA1)) == NULL ||
(r = sshbuf_get_bignum1(copy, pub->rsa->n)) != 0 ||
(r = sshbuf_get_bignum1(copy, pub->rsa->e)) != 0)
goto out;
/* Finally, the comment */
if ((r = sshbuf_get_string(copy, (u_char**)commentp, NULL)) != 0)
goto out;
/* The encrypted private part is not parsed by this function. */
r = 0;
*keyp = pub;
pub = NULL;
out:
if (copy != NULL)
sshbuf_free(copy);
if (pub != NULL)
sshkey_free(pub);
return r;
}
int
sshauthopt_deserialise(struct sshbuf *m, struct sshauthopt **optsp)
{
struct sshauthopt *opts = NULL;
int r = SSH_ERR_INTERNAL_ERROR;
u_char f;
u_int tmp;
if ((opts = calloc(1, sizeof(*opts))) == NULL)
return SSH_ERR_ALLOC_FAIL;
#define OPT_FLAG(x) \
do { \
if ((r = sshbuf_get_u8(m, &f)) != 0) \
goto out; \
opts->x = f; \
} while (0)
OPT_FLAG(permit_port_forwarding_flag);
OPT_FLAG(permit_agent_forwarding_flag);
OPT_FLAG(permit_x11_forwarding_flag);
OPT_FLAG(permit_pty_flag);
OPT_FLAG(permit_user_rc);
OPT_FLAG(restricted);
OPT_FLAG(cert_authority);
#undef OPT_FLAG
if ((r = sshbuf_get_u64(m, &opts->valid_before)) != 0)
goto out;
/* tunnel number can be negative to indicate "unset" */
if ((r = sshbuf_get_u8(m, &f)) != 0 ||
(r = sshbuf_get_u32(m, &tmp)) != 0)
goto out;
opts->force_tun_device = f ? -1 : (int)tmp;
/* String options may be NULL */
if ((r = deserialise_nullable_string(m, &opts->cert_principals)) != 0 ||
(r = deserialise_nullable_string(m, &opts->force_command)) != 0 ||
(r = deserialise_nullable_string(m,
&opts->required_from_host_cert)) != 0 ||
(r = deserialise_nullable_string(m,
&opts->required_from_host_keys)) != 0)
goto out;
/* Array options */
if ((r = deserialise_array(m, &opts->env, &opts->nenv)) != 0 ||
(r = deserialise_array(m,
&opts->permitopen, &opts->npermitopen)) != 0)
goto out;
/* success */
r = 0;
*optsp = opts;
opts = NULL;
out:
sshauthopt_free(opts);
return r;
}
/*
* Adds an identity to the authentication server.
* This call is intended only for use by ssh-add(1) and like applications.
*/
int
ssh_add_identity_constrained(int sock, struct sshkey *key, const char *comment,
u_int life, u_int confirm)
{
struct sshbuf *msg;
int r, constrained = (life || confirm);
u_char type;
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
switch (key->type) {
#ifdef WITH_SSH1
case KEY_RSA1:
type = constrained ?
SSH_AGENTC_ADD_RSA_ID_CONSTRAINED :
SSH_AGENTC_ADD_RSA_IDENTITY;
if ((r = sshbuf_put_u8(msg, type)) != 0 ||
(r = ssh_encode_identity_rsa1(msg, key->rsa, comment)) != 0)
goto out;
break;
#endif
#ifdef WITH_OPENSSL
case KEY_RSA:
case KEY_RSA_CERT:
case KEY_RSA_CERT_V00:
case KEY_DSA:
case KEY_DSA_CERT:
case KEY_DSA_CERT_V00:
case KEY_ECDSA:
case KEY_ECDSA_CERT:
#endif
case KEY_ED25519:
case KEY_ED25519_CERT:
type = constrained ?
SSH2_AGENTC_ADD_ID_CONSTRAINED :
SSH2_AGENTC_ADD_IDENTITY;
if ((r = sshbuf_put_u8(msg, type)) != 0 ||
(r = ssh_encode_identity_ssh2(msg, key, comment)) != 0)
goto out;
break;
default:
r = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
if (constrained &&
(r = encode_constraints(msg, life, confirm)) != 0)
goto out;
if ((r = ssh_request_reply(sock, msg, msg)) != 0)
goto out;
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
r = decode_reply(type);
out:
sshbuf_free(msg);
return r;
}
int
sshkey_xmss_deserialize_state(struct sshkey *k, struct sshbuf *b)
{
struct ssh_xmss_state *state = k->xmss_state;
treehash_inst *th;
u_int32_t i, lh, node;
size_t ls, lsl, la, lk, ln, lr;
char *magic;
int r;
if (state == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if (k->xmss_sk == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if ((state->treehash = calloc(num_treehash(state),
sizeof(treehash_inst))) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_get_cstring(b, &magic, NULL)) != 0 ||
(r = sshbuf_get_u32(b, &state->idx)) != 0 ||
(r = sshbuf_get_string(b, &state->stack, &ls)) != 0 ||
(r = sshbuf_get_u32(b, &state->stackoffset)) != 0 ||
(r = sshbuf_get_string(b, &state->stacklevels, &lsl)) != 0 ||
(r = sshbuf_get_string(b, &state->auth, &la)) != 0 ||
(r = sshbuf_get_string(b, &state->keep, &lk)) != 0 ||
(r = sshbuf_get_string(b, &state->th_nodes, &ln)) != 0 ||
(r = sshbuf_get_string(b, &state->retain, &lr)) != 0 ||
(r = sshbuf_get_u32(b, &lh)) != 0)
return r;
if (strcmp(magic, SSH_XMSS_K2_MAGIC) != 0)
return SSH_ERR_INVALID_ARGUMENT;
/* XXX check stackoffset */
if (ls != num_stack(state) ||
lsl != num_stacklevels(state) ||
la != num_auth(state) ||
lk != num_keep(state) ||
ln != num_th_nodes(state) ||
lr != num_retain(state) ||
lh != num_treehash(state))
return SSH_ERR_INVALID_ARGUMENT;
for (i = 0; i < num_treehash(state); i++) {
th = &state->treehash[i];
if ((r = sshbuf_get_u32(b, &th->h)) != 0 ||
(r = sshbuf_get_u32(b, &th->next_idx)) != 0 ||
(r = sshbuf_get_u32(b, &th->stackusage)) != 0 ||
(r = sshbuf_get_u8(b, &th->completed)) != 0 ||
(r = sshbuf_get_u32(b, &node)) != 0)
return r;
if (node < num_th_nodes(state))
th->node = &state->th_nodes[node];
}
POKE_U32(k->xmss_sk, state->idx);
xmss_set_bds_state(&state->bds, state->stack, state->stackoffset,
state->stacklevels, state->auth, state->keep, state->treehash,
state->retain, 0);
return 0;
}
int
buffer_get_char_ret(char *v, Buffer *buffer)
{
int ret;
if ((ret = sshbuf_get_u8(buffer, (u_char *)v)) != 0) {
error("%s: %s", __func__, ssh_err(ret));
return -1;
}
return 0;
}
static int
deserialise_nullable_string(struct sshbuf *m, char **sp)
{
int r;
u_char flag;
*sp = NULL;
if ((r = sshbuf_get_u8(m, &flag)) != 0 ||
(r = sshbuf_get_cstring(m, flag ? NULL : sp, NULL)) != 0)
return r;
return 0;
}
/* ask agent to sign data, returns err.h code on error, 0 on success */
int
ssh_agent_sign(int sock, struct sshkey *key,
u_char **sigp, size_t *lenp,
const u_char *data, size_t datalen, u_int compat)
{
struct sshbuf *msg;
u_char *blob = NULL, type;
size_t blen = 0, len = 0;
u_int flags = 0;
int r = SSH_ERR_INTERNAL_ERROR;
if (sigp != NULL)
*sigp = NULL;
if (lenp != NULL)
*lenp = 0;
if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
return SSH_ERR_INVALID_ARGUMENT;
if (compat & SSH_BUG_SIGBLOB)
flags |= SSH_AGENT_OLD_SIGNATURE;
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
goto out;
if ((r = sshbuf_put_u8(msg, SSH2_AGENTC_SIGN_REQUEST)) != 0 ||
(r = sshbuf_put_string(msg, blob, blen)) != 0 ||
(r = sshbuf_put_string(msg, data, datalen)) != 0 ||
(r = sshbuf_put_u32(msg, flags)) != 0)
goto out;
if ((r = ssh_request_reply(sock, msg, msg) != 0))
goto out;
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
if (agent_failed(type)) {
r = SSH_ERR_AGENT_FAILURE;
goto out;
} else if (type != SSH2_AGENT_SIGN_RESPONSE) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if ((r = sshbuf_get_string(msg, sigp, &len)) != 0)
goto out;
*lenp = len;
r = 0;
out:
if (blob != NULL) {
explicit_bzero(blob, blen);
free(blob);
}
sshbuf_free(msg);
return r;
}
/*
* Removes an identity from the authentication server.
* This call is intended only for use by ssh-add(1) and like applications.
*/
int
ssh_remove_identity(int sock, struct sshkey *key)
{
struct sshbuf *msg;
int r;
u_char type, *blob = NULL;
size_t blen;
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
#ifdef WITH_SSH1
if (key->type == KEY_RSA1) {
if ((r = sshbuf_put_u8(msg,
SSH_AGENTC_REMOVE_RSA_IDENTITY)) != 0 ||
(r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
(r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
(r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0)
goto out;
} else
#endif
if (key->type != KEY_UNSPEC) {
if ((r = sshkey_to_blob(key, &blob, &blen)) != 0)
goto out;
if ((r = sshbuf_put_u8(msg,
SSH2_AGENTC_REMOVE_IDENTITY)) != 0 ||
(r = sshbuf_put_string(msg, blob, blen)) != 0)
goto out;
} else {
r = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
if ((r = ssh_request_reply(sock, msg, msg)) != 0)
goto out;
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
r = decode_reply(type);
out:
if (blob != NULL) {
explicit_bzero(blob, blen);
free(blob);
}
sshbuf_free(msg);
return r;
}
static struct sshkey *
keygrab_ssh1(con *c)
{
static struct sshkey *rsa;
static struct sshbuf *msg;
int r;
u_char type;
if (rsa == NULL) {
if ((rsa = sshkey_new(KEY_RSA1)) == NULL) {
error("%s: sshkey_new failed", __func__);
return NULL;
}
if ((msg = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
}
if ((r = sshbuf_put(msg, c->c_data, c->c_plen)) != 0 ||
(r = sshbuf_consume(msg, 8 - (c->c_plen & 7))) != 0 || /* padding */
(r = sshbuf_get_u8(msg, &type)) != 0)
goto buf_err;
if (type != (int) SSH_SMSG_PUBLIC_KEY) {
error("%s: invalid packet type", c->c_name);
sshbuf_reset(msg);
return NULL;
}
if ((r = sshbuf_consume(msg, 8)) != 0 || /* cookie */
/* server key */
(r = sshbuf_get_u32(msg, NULL)) != 0 ||
(r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
(r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
/* host key */
(r = sshbuf_get_u32(msg, NULL)) != 0 ||
(r = sshbuf_get_bignum1(msg, rsa->rsa->e)) != 0 ||
(r = sshbuf_get_bignum1(msg, rsa->rsa->n)) != 0) {
buf_err:
error("%s: buffer error: %s", __func__, ssh_err(r));
sshbuf_reset(msg);
return NULL;
}
sshbuf_reset(msg);
return (rsa);
}
int
sshkey_xmss_deserialize_pk_info(struct sshkey *k, struct sshbuf *b)
{
struct ssh_xmss_state *state = k->xmss_state;
u_char have_info;
int r;
if (state == NULL)
return SSH_ERR_INVALID_ARGUMENT;
/* optional */
if (sshbuf_len(b) == 0)
return 0;
if ((r = sshbuf_get_u8(b, &have_info)) != 0)
return r;
if (have_info != 1)
return SSH_ERR_INVALID_ARGUMENT;
if ((r = sshbuf_get_u32(b, &state->idx)) != 0 ||
(r = sshbuf_get_u32(b, &state->maxidx)) != 0)
return r;
return 0;
}
/* Lock/unlock agent */
int
ssh_lock_agent(int sock, int lock, const char *password)
{
int r;
u_char type = lock ? SSH_AGENTC_LOCK : SSH_AGENTC_UNLOCK;
struct sshbuf *msg;
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_put_u8(msg, type)) != 0 ||
(r = sshbuf_put_cstring(msg, password)) != 0)
goto out;
if ((r = ssh_request_reply(sock, msg, msg)) != 0)
goto out;
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
r = decode_reply(type);
out:
sshbuf_free(msg);
return r;
}
static void
attempt_parse_blob(u_char *blob, size_t len)
{
struct sshbuf *p1;
BIGNUM *bn;
#ifdef OPENSSL_HAS_NISTP256
EC_KEY *eck;
#endif
u_char *s;
size_t l;
u_int8_t u8;
u_int16_t u16;
u_int32_t u32;
u_int64_t u64;
p1 = sshbuf_new();
ASSERT_PTR_NE(p1, NULL);
ASSERT_INT_EQ(sshbuf_put(p1, blob, len), 0);
sshbuf_get_u8(p1, &u8);
sshbuf_get_u16(p1, &u16);
sshbuf_get_u32(p1, &u32);
sshbuf_get_u64(p1, &u64);
if (sshbuf_get_string(p1, &s, &l) == 0) {
bzero(s, l);
free(s);
}
bn = BN_new();
sshbuf_get_bignum1(p1, bn);
BN_clear_free(bn);
bn = BN_new();
sshbuf_get_bignum2(p1, bn);
BN_clear_free(bn);
#ifdef OPENSSL_HAS_NISTP256
eck = EC_KEY_new_by_curve_name(NID_X9_62_prime256v1);
ASSERT_PTR_NE(eck, NULL);
sshbuf_get_eckey(p1, eck);
EC_KEY_free(eck);
#endif
sshbuf_free(p1);
}
/* parse buffer and return algorithm proposal */
int
kex_buf2prop(struct sshbuf *raw, int *first_kex_follows, char ***propp)
{
struct sshbuf *b = NULL;
u_char v;
u_int i;
char **proposal = NULL;
int r;
if ((proposal = calloc(PROPOSAL_MAX, sizeof(char *))) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((b = sshbuf_new()) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshbuf_putb(b, raw)) != 0 ||
(r = sshbuf_consume(b, KEX_COOKIE_LEN)) != 0) /* skip cookie */
goto out;
/* extract kex init proposal strings */
for (i = 0; i < PROPOSAL_MAX; i++) {
if ((r = sshbuf_get_cstring(b, &(proposal[i]), NULL)) != 0)
goto out;
debug2("kex_parse_kexinit: %s", proposal[i]);
}
/* first kex follows / reserved */
if ((r = sshbuf_get_u8(b, &v)) != 0 ||
(r = sshbuf_get_u32(b, &i)) != 0)
goto out;
if (first_kex_follows != NULL)
*first_kex_follows = i;
debug2("kex_parse_kexinit: first_kex_follows %d ", v);
debug2("kex_parse_kexinit: reserved %u ", i);
r = 0;
*propp = proposal;
out:
if (r != 0 && proposal != NULL)
kex_prop_free(proposal);
sshbuf_free(b);
return r;
}
/*
* Removes all identities from the agent.
* This call is intended only for use by ssh-add(1) and like applications.
*/
int
ssh_remove_all_identities(int sock, int version)
{
struct sshbuf *msg;
u_char type = (version == 1) ?
SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES :
SSH2_AGENTC_REMOVE_ALL_IDENTITIES;
int r;
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_put_u8(msg, type)) != 0)
goto out;
if ((r = ssh_request_reply(sock, msg, msg)) != 0)
goto out;
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
r = decode_reply(type);
out:
sshbuf_free(msg);
return r;
}
int
ssh_decrypt_challenge(int sock, struct sshkey* key, BIGNUM *challenge,
u_char session_id[16], u_char response[16])
{
struct sshbuf *msg;
int r;
u_char type;
if (key->type != KEY_RSA1)
return SSH_ERR_INVALID_ARGUMENT;
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_put_u8(msg, SSH_AGENTC_RSA_CHALLENGE)) != 0 ||
(r = sshbuf_put_u32(msg, BN_num_bits(key->rsa->n))) != 0 ||
(r = sshbuf_put_bignum1(msg, key->rsa->e)) != 0 ||
(r = sshbuf_put_bignum1(msg, key->rsa->n)) != 0 ||
(r = sshbuf_put_bignum1(msg, challenge)) != 0 ||
(r = sshbuf_put(msg, session_id, 16)) != 0 ||
(r = sshbuf_put_u32(msg, 1)) != 0) /* Response type for proto 1.1 */
goto out;
if ((r = ssh_request_reply(sock, msg, msg)) != 0)
goto out;
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
if (agent_failed(type)) {
r = SSH_ERR_AGENT_FAILURE;
goto out;
} else if (type != SSH_AGENT_RSA_RESPONSE) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if ((r = sshbuf_get(msg, response, 16)) != 0)
goto out;
r = 0;
out:
sshbuf_free(msg);
return r;
}
/*
* Fetch list of identities held by the agent.
*/
int
ssh_fetch_identitylist(int sock, int version, struct ssh_identitylist **idlp)
{
u_char type, code1 = 0, code2 = 0;
u_int32_t num, i;
struct sshbuf *msg;
struct ssh_identitylist *idl = NULL;
int r;
/* Determine request and expected response types */
switch (version) {
case 1:
code1 = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
code2 = SSH_AGENT_RSA_IDENTITIES_ANSWER;
break;
case 2:
code1 = SSH2_AGENTC_REQUEST_IDENTITIES;
code2 = SSH2_AGENT_IDENTITIES_ANSWER;
break;
default:
return SSH_ERR_INVALID_ARGUMENT;
}
/*
* Send a message to the agent requesting for a list of the
* identities it can represent.
*/
if ((msg = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((r = sshbuf_put_u8(msg, code1)) != 0)
goto out;
if ((r = ssh_request_reply(sock, msg, msg)) != 0)
goto out;
/* Get message type, and verify that we got a proper answer. */
if ((r = sshbuf_get_u8(msg, &type)) != 0)
goto out;
if (agent_failed(type)) {
r = SSH_ERR_AGENT_FAILURE;
goto out;
} else if (type != code2) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
/* Get the number of entries in the response and check it for sanity. */
if ((r = sshbuf_get_u32(msg, &num)) != 0)
goto out;
if (num > MAX_AGENT_IDENTITIES) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (num == 0) {
r = SSH_ERR_AGENT_NO_IDENTITIES;
goto out;
}
/* Deserialise the response into a list of keys/comments */
if ((idl = calloc(1, sizeof(*idl))) == NULL ||
(idl->keys = calloc(num, sizeof(*idl->keys))) == NULL ||
(idl->comments = calloc(num, sizeof(*idl->comments))) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
for (i = 0; i < num;) {
switch (version) {
case 1:
#ifdef WITH_SSH1
if ((r = deserialise_identity1(msg,
&(idl->keys[i]), &(idl->comments[i]))) != 0)
goto out;
#endif
break;
case 2:
if ((r = deserialise_identity2(msg,
&(idl->keys[i]), &(idl->comments[i]))) != 0) {
if (r == SSH_ERR_KEY_TYPE_UNKNOWN) {
/* Gracefully skip unknown key types */
num--;
continue;
} else
goto out;
}
break;
}
i++;
}
idl->nkeys = num;
*idlp = idl;
idl = NULL;
r = 0;
out:
sshbuf_free(msg);
if (idl != NULL)
ssh_free_identitylist(idl);
return r;
}
static int
valid_request(struct passwd *pw, char *host, struct sshkey **ret,
u_char *data, size_t datalen)
{
struct sshbuf *b;
struct sshkey *key = NULL;
u_char type, *pkblob;
char *p;
size_t blen, len;
char *pkalg, *luser;
int r, pktype, fail;
if (ret != NULL)
*ret = NULL;
fail = 0;
if ((b = sshbuf_from(data, datalen)) == NULL)
fatal("%s: sshbuf_from failed", __func__);
/* session id, currently limited to SHA1 (20 bytes) or SHA256 (32) */
if ((r = sshbuf_get_string(b, NULL, &len)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (len != 20 && len != 32)
fail++;
if ((r = sshbuf_get_u8(b, &type)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (type != SSH2_MSG_USERAUTH_REQUEST)
fail++;
/* server user */
if ((r = sshbuf_skip_string(b)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
/* service */
if ((r = sshbuf_get_cstring(b, &p, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (strcmp("ssh-connection", p) != 0)
fail++;
free(p);
/* method */
if ((r = sshbuf_get_cstring(b, &p, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (strcmp("hostbased", p) != 0)
fail++;
free(p);
/* pubkey */
if ((r = sshbuf_get_cstring(b, &pkalg, NULL)) != 0 ||
(r = sshbuf_get_string(b, &pkblob, &blen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
pktype = sshkey_type_from_name(pkalg);
if (pktype == KEY_UNSPEC)
fail++;
else if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
error("%s: bad key blob: %s", __func__, ssh_err(r));
fail++;
} else if (key->type != pktype)
fail++;
free(pkalg);
free(pkblob);
/* client host name, handle trailing dot */
if ((r = sshbuf_get_cstring(b, &p, &len)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
debug2("%s: check expect chost %s got %s", __func__, host, p);
if (strlen(host) != len - 1)
fail++;
else if (p[len - 1] != '.')
fail++;
else if (strncasecmp(host, p, len - 1) != 0)
fail++;
free(p);
/* local user */
if ((r = sshbuf_get_cstring(b, &luser, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (strcmp(pw->pw_name, luser) != 0)
fail++;
free(luser);
/* end of message */
if (sshbuf_len(b) != 0)
fail++;
sshbuf_free(b);
debug3("%s: fail %d", __func__, fail);
if (fail && key != NULL)
sshkey_free(key);
else if (ret != NULL)
*ret = key;
return (fail ? -1 : 0);
}
int
main(int argc, char **argv)
{
struct sshbuf *b;
Options options;
#define NUM_KEYTYPES 4
struct sshkey *keys[NUM_KEYTYPES], *key = NULL;
struct passwd *pw;
int r, key_fd[NUM_KEYTYPES], i, found, version = 2, fd;
u_char *signature, *data, rver;
char *host, *fp;
size_t slen, dlen;
#ifdef WITH_OPENSSL
u_int32_t rnd[256];
#endif
if (pledge("stdio rpath getpw dns id", NULL) != 0)
fatal("%s: pledge: %s", __progname, strerror(errno));
/* Ensure that stdin and stdout are connected */
if ((fd = open(_PATH_DEVNULL, O_RDWR)) < 2)
exit(1);
/* Leave /dev/null fd iff it is attached to stderr */
if (fd > 2)
close(fd);
i = 0;
/* XXX This really needs to read sshd_config for the paths */
key_fd[i++] = open(_PATH_HOST_DSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_ECDSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_ED25519_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_RSA_KEY_FILE, O_RDONLY);
original_real_uid = getuid(); /* XXX readconf.c needs this */
if ((pw = getpwuid(original_real_uid)) == NULL)
fatal("getpwuid failed");
pw = pwcopy(pw);
permanently_set_uid(pw);
seed_rng();
#ifdef DEBUG_SSH_KEYSIGN
log_init("ssh-keysign", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 0);
#endif
/* verify that ssh-keysign is enabled by the admin */
initialize_options(&options);
(void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, "", "", &options, 0);
fill_default_options(&options);
if (options.enable_ssh_keysign != 1)
fatal("ssh-keysign not enabled in %s",
_PATH_HOST_CONFIG_FILE);
for (i = found = 0; i < NUM_KEYTYPES; i++) {
if (key_fd[i] != -1)
found = 1;
}
if (found == 0)
fatal("could not open any host key");
#ifdef WITH_OPENSSL
OpenSSL_add_all_algorithms();
arc4random_buf(rnd, sizeof(rnd));
RAND_seed(rnd, sizeof(rnd));
#endif
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
keys[i] = NULL;
if (key_fd[i] == -1)
continue;
r = sshkey_load_private_type_fd(key_fd[i], KEY_UNSPEC,
NULL, &key, NULL);
close(key_fd[i]);
if (r != 0)
debug("parse key %d: %s", i, ssh_err(r));
else if (key != NULL) {
keys[i] = key;
found = 1;
}
}
if (!found)
fatal("no hostkey found");
if (pledge("stdio dns", NULL) != 0)
fatal("%s: pledge: %s", __progname, strerror(errno));
if ((b = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __progname);
if (ssh_msg_recv(STDIN_FILENO, b) < 0)
fatal("ssh_msg_recv failed");
if ((r = sshbuf_get_u8(b, &rver)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (rver != version)
fatal("bad version: received %d, expected %d", rver, version);
if ((r = sshbuf_get_u32(b, (u_int *)&fd)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (fd < 0 || fd == STDIN_FILENO || fd == STDOUT_FILENO)
fatal("bad fd");
if ((host = get_local_name(fd)) == NULL)
fatal("cannot get local name for fd");
if ((r = sshbuf_get_string(b, &data, &dlen)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (valid_request(pw, host, &key, data, dlen) < 0)
fatal("not a valid request");
free(host);
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
if (keys[i] != NULL &&
sshkey_equal_public(key, keys[i])) {
found = 1;
break;
}
}
if (!found) {
if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
SSH_FP_DEFAULT)) == NULL)
fatal("%s: sshkey_fingerprint failed", __progname);
fatal("no matching hostkey found for key %s %s",
sshkey_type(key), fp ? fp : "");
}
if ((r = sshkey_sign(keys[i], &signature, &slen, data, dlen, NULL, 0))
!= 0)
fatal("sshkey_sign failed: %s", ssh_err(r));
free(data);
/* send reply */
sshbuf_reset(b);
if ((r = sshbuf_put_string(b, signature, slen)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (ssh_msg_send(STDOUT_FILENO, version, b) == -1)
fatal("ssh_msg_send failed");
return (0);
}
static int
sshkey_parse_private_rsa1(struct sshbuf *blob, const char *passphrase,
struct sshkey **keyp, char **commentp)
{
int r;
u_int16_t check1, check2;
u_int8_t cipher_type;
struct sshbuf *decrypted = NULL, *copy = NULL;
u_char *cp;
char *comment = NULL;
struct sshcipher_ctx ciphercontext;
const struct sshcipher *cipher;
struct sshkey *prv = NULL;
*keyp = NULL;
if (commentp != NULL)
*commentp = NULL;
/* Check that it is at least big enough to contain the ID string. */
if (sshbuf_len(blob) < sizeof(authfile_id_string))
return SSH_ERR_INVALID_FORMAT;
/*
* Make sure it begins with the id string. Consume the id string
* from the buffer.
*/
if (memcmp(sshbuf_ptr(blob), authfile_id_string,
sizeof(authfile_id_string)) != 0)
return SSH_ERR_INVALID_FORMAT;
if ((prv = sshkey_new_private(KEY_RSA1)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((copy = sshbuf_fromb(blob)) == NULL ||
(decrypted = sshbuf_new()) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshbuf_consume(copy, sizeof(authfile_id_string))) != 0)
goto out;
/* Read cipher type. */
if ((r = sshbuf_get_u8(copy, &cipher_type)) != 0 ||
(r = sshbuf_get_u32(copy, NULL)) != 0) /* reserved */
goto out;
/* Read the public key and comment from the buffer. */
if ((r = sshbuf_get_u32(copy, NULL)) != 0 || /* key bits */
(r = sshbuf_get_bignum1(copy, prv->rsa->n)) != 0 ||
(r = sshbuf_get_bignum1(copy, prv->rsa->e)) != 0 ||
(r = sshbuf_get_cstring(copy, &comment, NULL)) != 0)
goto out;
/* Check that it is a supported cipher. */
cipher = cipher_by_number(cipher_type);
if (cipher == NULL) {
r = SSH_ERR_KEY_UNKNOWN_CIPHER;
goto out;
}
/* Initialize space for decrypted data. */
if ((r = sshbuf_reserve(decrypted, sshbuf_len(copy), &cp)) != 0)
goto out;
/* Rest of the buffer is encrypted. Decrypt it using the passphrase. */
if ((r = cipher_set_key_string(&ciphercontext, cipher, passphrase,
CIPHER_DECRYPT)) != 0)
goto out;
if ((r = cipher_crypt(&ciphercontext, cp,
sshbuf_ptr(copy), sshbuf_len(copy), 0, 0)) != 0) {
cipher_cleanup(&ciphercontext);
goto out;
}
if ((r = cipher_cleanup(&ciphercontext)) != 0)
goto out;
if ((r = sshbuf_get_u16(decrypted, &check1)) != 0 ||
(r = sshbuf_get_u16(decrypted, &check2)) != 0)
goto out;
if (check1 != check2) {
r = SSH_ERR_KEY_WRONG_PASSPHRASE;
goto out;
}
/* Read the rest of the private key. */
if ((r = sshbuf_get_bignum1(decrypted, prv->rsa->d)) != 0 ||
(r = sshbuf_get_bignum1(decrypted, prv->rsa->iqmp)) != 0 ||
(r = sshbuf_get_bignum1(decrypted, prv->rsa->q)) != 0 ||
(r = sshbuf_get_bignum1(decrypted, prv->rsa->p)) != 0)
goto out;
/* calculate p-1 and q-1 */
if ((r = rsa_generate_additional_parameters(prv->rsa)) != 0)
goto out;
/* enable blinding */
if (RSA_blinding_on(prv->rsa, NULL) != 1) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
r = 0;
*keyp = prv;
prv = NULL;
if (commentp != NULL) {
*commentp = comment;
comment = NULL;
}
out:
bzero(&ciphercontext, sizeof(ciphercontext));
if (comment != NULL)
free(comment);
if (prv != NULL)
sshkey_free(prv);
if (copy != NULL)
sshbuf_free(copy);
if (decrypted != NULL)
sshbuf_free(decrypted);
return r;
}
/*
* Decodes terminal modes for the terminal referenced by fd in a portable
* manner from a packet being read.
*/
void
ssh_tty_parse_modes(struct ssh *ssh, int fd)
{
struct termios tio;
struct sshbuf *buf;
const u_char *data;
u_char opcode;
u_int baud, u;
int r, failure = 0;
size_t len;
if ((r = sshpkt_get_string_direct(ssh, &data, &len)) != 0)
fatal("%s: packet error: %s", __func__, ssh_err(r));
if (len == 0)
return;
if ((buf = sshbuf_from(data, len)) == NULL) {
error("%s: sshbuf_from failed", __func__);
return;
}
/*
* Get old attributes for the terminal. We will modify these
* flags. I am hoping that if there are any machine-specific
* modes, they will initially have reasonable values.
*/
if (tcgetattr(fd, &tio) == -1) {
logit("tcgetattr: %.100s", strerror(errno));
failure = -1;
}
while (sshbuf_len(buf) > 0) {
if ((r = sshbuf_get_u8(buf, &opcode)) != 0)
fatal("%s: packet error: %s", __func__, ssh_err(r));
switch (opcode) {
case TTY_OP_END:
goto set;
case TTY_OP_ISPEED:
if ((r = sshbuf_get_u32(buf, &baud)) != 0)
fatal("%s: packet error: %s",
__func__, ssh_err(r));
if (failure != -1 &&
cfsetispeed(&tio, baud_to_speed(baud)) == -1)
error("cfsetispeed failed for %d", baud);
break;
case TTY_OP_OSPEED:
if ((r = sshbuf_get_u32(buf, &baud)) != 0)
fatal("%s: packet error: %s",
__func__, ssh_err(r));
if (failure != -1 &&
cfsetospeed(&tio, baud_to_speed(baud)) == -1)
error("cfsetospeed failed for %d", baud);
break;
#define TTYCHAR(NAME, OP) \
case OP: \
if ((r = sshbuf_get_u32(buf, &u)) != 0) \
fatal("%s: packet error: %s", __func__, \
ssh_err(r)); \
tio.c_cc[NAME] = u; \
break;
#define TTYMODE(NAME, FIELD, OP) \
case OP: \
if ((r = sshbuf_get_u32(buf, &u)) != 0) \
fatal("%s: packet error: %s", __func__, \
ssh_err(r)); \
if (u) \
tio.FIELD |= NAME; \
else \
tio.FIELD &= ~NAME; \
break;
#include "ttymodes.h"
#undef TTYCHAR
#undef TTYMODE
default:
debug("Ignoring unsupported tty mode opcode %d (0x%x)",
opcode, opcode);
/*
* SSH2:
* Opcodes 1 to 159 are defined to have a uint32
* argument.
* Opcodes 160 to 255 are undefined and cause parsing
* to stop.
*/
if (opcode > 0 && opcode < 160) {
if ((r = sshbuf_get_u32(buf, NULL)) != 0)
fatal("%s: packet error: %s", __func__,
ssh_err(r));
break;
} else {
logit("%s: unknown opcode %d", __func__,
opcode);
goto set;
}
}
}
set:
len = sshbuf_len(buf);
sshbuf_free(buf);
if (len > 0) {
logit("%s: %zu bytes left", __func__, len);
return; /* Don't process bytes passed */
}
if (failure == -1)
return; /* Packet parsed ok but tcgetattr() failed */
/* Set the new modes for the terminal. */
if (tcsetattr(fd, TCSANOW, &tio) == -1)
logit("Setting tty modes failed: %.100s", strerror(errno));
}
/*
* Conversation function for authentication thread.
*/
static int
sshpam_thread_conv(int n, sshpam_const struct pam_message **msg,
struct pam_response **resp, void *data)
{
struct sshbuf *buffer;
struct pam_ctxt *ctxt;
struct pam_response *reply;
int r, i;
u_char status;
debug3("PAM: %s entering, %d messages", __func__, n);
*resp = NULL;
if (data == NULL) {
error("PAM: conversation function passed a null context");
return (PAM_CONV_ERR);
}
ctxt = data;
if (n <= 0 || n > PAM_MAX_NUM_MSG)
return (PAM_CONV_ERR);
if ((reply = calloc(n, sizeof(*reply))) == NULL)
return PAM_CONV_ERR;
if ((buffer = sshbuf_new()) == NULL) {
free(reply);
return PAM_CONV_ERR;
}
for (i = 0; i < n; ++i) {
switch (PAM_MSG_MEMBER(msg, i, msg_style)) {
case PAM_PROMPT_ECHO_OFF:
case PAM_PROMPT_ECHO_ON:
if ((r = sshbuf_put_cstring(buffer,
PAM_MSG_MEMBER(msg, i, msg))) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
if (ssh_msg_send(ctxt->pam_csock,
PAM_MSG_MEMBER(msg, i, msg_style), buffer) == -1)
goto fail;
if (ssh_msg_recv(ctxt->pam_csock, buffer) == -1)
goto fail;
if ((r = sshbuf_get_u8(buffer, &status)) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
if (status != PAM_AUTHTOK)
goto fail;
if ((r = sshbuf_get_cstring(buffer,
&reply[i].resp, NULL)) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
break;
case PAM_ERROR_MSG:
case PAM_TEXT_INFO:
if ((r = sshbuf_put_cstring(buffer,
PAM_MSG_MEMBER(msg, i, msg))) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
if (ssh_msg_send(ctxt->pam_csock,
PAM_MSG_MEMBER(msg, i, msg_style), buffer) == -1)
goto fail;
break;
default:
goto fail;
}
sshbuf_reset(buffer);
}
sshbuf_free(buffer);
*resp = reply;
return (PAM_SUCCESS);
fail:
for(i = 0; i < n; i++) {
free(reply[i].resp);
}
free(reply);
sshbuf_free(buffer);
return (PAM_CONV_ERR);
}
static int
sshpam_query(void *ctx, char **name, char **info,
u_int *num, char ***prompts, u_int **echo_on)
{
struct ssh *ssh = active_state; /* XXX */
struct sshbuf *buffer;
struct pam_ctxt *ctxt = ctx;
size_t plen;
u_char type;
char *msg;
size_t len, mlen;
int r;
debug3("PAM: %s entering", __func__);
if ((buffer = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
*name = xstrdup("");
*info = xstrdup("");
*prompts = xmalloc(sizeof(char *));
**prompts = NULL;
plen = 0;
*echo_on = xmalloc(sizeof(u_int));
while (ssh_msg_recv(ctxt->pam_psock, buffer) == 0) {
if ((r = sshbuf_get_u8(buffer, &type)) != 0 ||
(r = sshbuf_get_cstring(buffer, &msg, &mlen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
switch (type) {
case PAM_PROMPT_ECHO_ON:
case PAM_PROMPT_ECHO_OFF:
*num = 1;
len = plen + mlen + 1;
**prompts = xreallocarray(**prompts, 1, len);
strlcpy(**prompts + plen, msg, len - plen);
plen += mlen;
**echo_on = (type == PAM_PROMPT_ECHO_ON);
free(msg);
return (0);
case PAM_ERROR_MSG:
case PAM_TEXT_INFO:
/* accumulate messages */
len = plen + mlen + 2;
**prompts = xreallocarray(**prompts, 1, len);
strlcpy(**prompts + plen, msg, len - plen);
plen += mlen;
strlcat(**prompts + plen, "\n", len - plen);
plen++;
free(msg);
break;
case PAM_ACCT_EXPIRED:
case PAM_MAXTRIES:
if (type == PAM_ACCT_EXPIRED)
sshpam_account_status = 0;
if (type == PAM_MAXTRIES)
sshpam_set_maxtries_reached(1);
/* FALLTHROUGH */
case PAM_AUTH_ERR:
debug3("PAM: %s", pam_strerror(sshpam_handle, type));
if (**prompts != NULL && strlen(**prompts) != 0) {
*info = **prompts;
**prompts = NULL;
*num = 0;
**echo_on = 0;
ctxt->pam_done = -1;
free(msg);
return 0;
}
/* FALLTHROUGH */
case PAM_SUCCESS:
if (**prompts != NULL) {
/* drain any accumulated messages */
debug("PAM: %s", **prompts);
if ((r = sshbuf_put(loginmsg, **prompts,
strlen(**prompts))) != 0)
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
free(**prompts);
**prompts = NULL;
}
if (type == PAM_SUCCESS) {
if (!sshpam_authctxt->valid ||
(sshpam_authctxt->pw->pw_uid == 0 &&
options.permit_root_login != PERMIT_YES))
fatal("Internal error: PAM auth "
"succeeded when it should have "
"failed");
import_environments(buffer);
*num = 0;
**echo_on = 0;
ctxt->pam_done = 1;
free(msg);
return (0);
}
BLACKLIST_NOTIFY(BLACKLIST_BAD_USER,
sshpam_authctxt->user);
error("PAM: %s for %s%.100s from %.100s", msg,
sshpam_authctxt->valid ? "" : "illegal user ",
sshpam_authctxt->user,
auth_get_canonical_hostname(ssh, options.use_dns));
/* FALLTHROUGH */
default:
*num = 0;
**echo_on = 0;
free(msg);
ctxt->pam_done = -1;
return (-1);
}
}
return (-1);
}
int
main(int argc, char **argv)
{
struct sshbuf *b;
Options options;
#define NUM_KEYTYPES 3
struct sshkey *keys[NUM_KEYTYPES], *key = NULL;
struct passwd *pw;
int r, key_fd[NUM_KEYTYPES], i, found, version = 2, fd;
u_char *signature, *data, rver;
char *host;
size_t slen, dlen;
u_int32_t rnd[256];
/* Ensure that stdin and stdout are connected */
if ((fd = open(_PATH_DEVNULL, O_RDWR)) < 2)
exit(1);
/* Leave /dev/null fd iff it is attached to stderr */
if (fd > 2)
close(fd);
i = 0;
key_fd[i++] = open(_PATH_HOST_DSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_ECDSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_RSA_KEY_FILE, O_RDONLY);
original_real_uid = getuid(); /* XXX readconf.c needs this */
if ((pw = getpwuid(original_real_uid)) == NULL)
fatal("getpwuid failed");
pw = pwcopy(pw);
permanently_set_uid(pw);
#ifdef DEBUG_SSH_KEYSIGN
log_init("ssh-keysign", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 0);
#endif
/* verify that ssh-keysign is enabled by the admin */
initialize_options(&options);
(void)read_config_file(_PATH_HOST_CONFIG_FILE, "", &options, 0);
fill_default_options(&options);
if (options.enable_ssh_keysign != 1)
fatal("ssh-keysign not enabled in %s",
_PATH_HOST_CONFIG_FILE);
for (i = found = 0; i < NUM_KEYTYPES; i++) {
if (key_fd[i] != -1)
found = 1;
}
if (found == 0)
fatal("could not open any host key");
OpenSSL_add_all_algorithms();
for (i = 0; i < 256; i++)
rnd[i] = arc4random();
RAND_seed(rnd, sizeof(rnd));
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
keys[i] = NULL;
if (key_fd[i] == -1)
continue;
r = sshkey_load_private_pem(key_fd[i], KEY_UNSPEC,
NULL, &(keys[i]), NULL);
if (r != 0)
error("Load private: %s", ssh_err(r));
close(key_fd[i]);
if (keys[i] != NULL)
found = 1;
}
if (!found)
fatal("no hostkey found");
if ((b = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if (ssh_msg_recv(STDIN_FILENO, b) < 0)
fatal("ssh_msg_recv failed");
if ((r = sshbuf_get_u8(b, &rver)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (rver != version)
fatal("bad version: received %d, expected %d", rver, version);
if ((r = sshbuf_get_u32(b, &fd)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if ((fd == STDIN_FILENO) || (fd == STDOUT_FILENO))
fatal("bad fd");
if ((host = get_local_name(fd)) == NULL)
fatal("cannot get local name for fd");
if ((r = sshbuf_get_string(b, &data, &dlen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (valid_request(pw, host, &key, data, dlen) < 0)
fatal("not a valid request");
xfree(host);
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
if (keys[i] != NULL &&
sshkey_equal_public(key, keys[i])) {
found = 1;
break;
}
}
if (!found)
fatal("no matching hostkey found");
if ((r = sshkey_sign(keys[i], &signature, &slen, data, dlen, 0)) != 0)
fatal("sshkey_sign failed: %s", ssh_err(r));
xfree(data);
/* send reply */
sshbuf_reset(b);
if ((r = sshbuf_put_string(b, signature, slen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (ssh_msg_send(STDOUT_FILENO, version, b) == -1)
fatal("ssh_msg_send failed");
return (0);
}
int
monitor_read(struct monitor *pmonitor, struct mon_table *ent,
struct mon_table **pent)
{
struct sshbuf *m;
int ret, r;
u_char type;
struct pollfd pfd[2];
for (;;) {
memset(&pfd, 0, sizeof(pfd));
pfd[0].fd = pmonitor->m_sendfd;
pfd[0].events = POLLIN;
pfd[1].fd = pmonitor->m_log_recvfd;
pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
fatal("%s: poll: %s", __func__, strerror(errno));
}
if (pfd[1].revents) {
/*
* Drain all log messages before processing next
* monitor request.
*/
monitor_read_log(pmonitor);
continue;
}
if (pfd[0].revents)
break; /* Continues below */
}
if ((m = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
mm_request_receive(pmonitor->m_sendfd, m);
if ((r = sshbuf_get_u8(m, &type)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
debug3("%s: checking request %d", __func__, type);
while (ent->f != NULL) {
if (ent->type == type)
break;
ent++;
}
if (ent->f != NULL) {
if (!(ent->flags & MON_PERMIT))
fatal("%s: unpermitted request %d", __func__,
type);
ret = (*ent->f)(pmonitor->m_sendfd, m);
sshbuf_free(m);
/* The child may use this request only once, disable it */
if (ent->flags & MON_ONCE) {
debug2("%s: %d used once, disabling now", __func__,
type);
ent->flags &= ~MON_PERMIT;
}
if (pent != NULL)
*pent = ent;
return ret;
}
fatal("%s: unsupported request: %d", __func__, type);
/* NOTREACHED */
return (-1);
}
static int
monitor_valid_userblob(u_char *data, u_int datalen)
{
struct sshbuf *b;
u_char *p, c;
const u_char *cp;
size_t len;
int r, fail = 0;
char *username, *methodname, *userstyle;
if ((b = sshbuf_from(data, datalen)) == NULL)
fatal("%s: sshbuf_from failed", __func__);
if (active_state->compat & SSH_OLD_SESSIONID) {
cp = sshbuf_ptr(b);
len = sshbuf_len(b);
if ((session_id2 == NULL) ||
(len < session_id2_len) ||
(timingsafe_bcmp(cp, session_id2, session_id2_len) != 0))
fail++;
if ((r = sshbuf_consume(b, session_id2_len)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
} else {
if ((r = sshbuf_get_string(b, &p, &len)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if ((session_id2 == NULL) ||
(len != session_id2_len) ||
(timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
fail++;
free(p);
}
if ((r = sshbuf_get_u8(b, &c)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (c != SSH2_MSG_USERAUTH_REQUEST)
fail++;
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
if ((r = sshbuf_get_cstring(b, &username, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (strcmp(userstyle, username) != 0) {
logit("wrong user name sent to monitor: expected %s != %.100s",
userstyle, username);
fail++;
}
free(username);
free(userstyle);
if ((r = sshbuf_skip_string(b)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (active_state->compat & SSH_BUG_PKAUTH) {
if ((r = sshbuf_get_u8(b, &c)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (!c)
fail++;
} else {
if ((r = sshbuf_get_cstring(b, &methodname, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (strcmp("publickey", methodname) != 0)
fail++;
free(methodname);
if ((r = sshbuf_get_u8(b, &c)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (!c)
fail++;
if ((r = sshbuf_skip_string(b)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
}
if ((r = sshbuf_skip_string(b)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (sshbuf_len(b) != 0)
fail++;
sshbuf_free(b);
return (fail == 0);
}
static void
process(void)
{
u_int msg_len;
u_int buf_len;
u_int consumed;
u_char type;
const u_char *cp;
int i, r;
u_int32_t id;
buf_len = sshbuf_len(iqueue);
if (buf_len < 5)
return; /* Incomplete message. */
cp = sshbuf_ptr(iqueue);
msg_len = get_u32(cp);
if (msg_len > SFTP_MAX_MSG_LENGTH) {
error("bad message from %s local user %s",
client_addr, pw->pw_name);
sftp_server_cleanup_exit(11);
}
if (buf_len < msg_len + 4)
return;
if ((r = sshbuf_consume(iqueue, 4)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
buf_len -= 4;
if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
switch (type) {
case SSH2_FXP_INIT:
process_init();
init_done = 1;
break;
case SSH2_FXP_EXTENDED:
if (!init_done)
fatal("Received extended request before init");
if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
process_extended(id);
break;
default:
if (!init_done)
fatal("Received %u request before init", type);
if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
for (i = 0; handlers[i].handler != NULL; i++) {
if (type == handlers[i].type) {
if (!request_permitted(&handlers[i])) {
send_status(id,
SSH2_FX_PERMISSION_DENIED);
} else {
handlers[i].handler(id);
}
break;
}
}
if (handlers[i].handler == NULL)
error("Unknown message %u", type);
}
/* discard the remaining bytes from the current packet */
if (buf_len < sshbuf_len(iqueue)) {
error("iqueue grew unexpectedly");
sftp_server_cleanup_exit(255);
}
consumed = buf_len - sshbuf_len(iqueue);
if (msg_len < consumed) {
error("msg_len %u < consumed %u", msg_len, consumed);
sftp_server_cleanup_exit(255);
}
if (msg_len > consumed &&
(r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
}
static int
monitor_valid_hostbasedblob(u_char *data, u_int datalen, char *cuser,
char *chost)
{
struct sshbuf *b;
char *username, *methodname, *rawhost, *ruser, *userstyle;
u_char *sid, c;
size_t len;
int r, fail = 0;
if ((b = sshbuf_from(data, datalen)) == NULL)
fatal("%s: sshbuf_from failed", __func__);
if ((r = sshbuf_get_string(b, &sid, &len)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if ((session_id2 == NULL) ||
(len != session_id2_len) ||
(timingsafe_bcmp(sid, session_id2, session_id2_len) != 0))
fail++;
free(sid);
if ((r = sshbuf_get_u8(b, &c)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (c != SSH2_MSG_USERAUTH_REQUEST)
fail++;
if ((r = sshbuf_get_cstring(b, &username, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
if (strcmp(userstyle, username) != 0) {
logit("wrong user name sent to monitor: expected %s != %.100s",
userstyle, username);
fail++;
}
free(userstyle);
free(username);
if ((r = sshbuf_skip_string(b)) != 0 || /* service */
(r = sshbuf_get_cstring(b, &methodname, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (strcmp("hostbased", methodname) != 0)
fail++;
free(methodname);
if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
(r = sshbuf_skip_string(b)) != 0) /* pkblob */
fatal("%s: buffer error: %s", __func__, ssh_err(r));
/* verify client host, strip trailing dot if necessary */
if ((r = sshbuf_get_cstring(b, &rawhost, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (((len = strlen(rawhost)) > 0) && rawhost[len - 1] == '.')
rawhost[len - 1] = '\0';
if (strcmp(rawhost, chost) != 0)
fail++;
free(rawhost);
/* verify client user */
if ((r = sshbuf_get_cstring(b, &ruser, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (strcmp(ruser, cuser) != 0)
fail++;
free(ruser);
if (sshbuf_len(b) != 0)
fail++;
sshbuf_free(b);
return (fail == 0);
}
