int
mm_answer_rsa_keyallowed(int sock, Buffer *m)
{
BIGNUM *client_n;
Key *key = NULL;
u_char *blob = NULL;
u_int blen = 0;
int allowed = 0;
debug3("%s entering", __func__);
auth_method = "rsa";
if (options.rsa_authentication && authctxt->valid) {
if ((client_n = BN_new()) == NULL)
fatal("%s: BN_new", __func__);
buffer_get_bignum2(m, client_n);
allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
BN_clear_free(client_n);
}
buffer_clear(m);
buffer_put_int(m, allowed);
buffer_put_int(m, forced_command != NULL);
/* clear temporarily storage (used by generate challenge) */
monitor_reset_key_state();
if (allowed && key != NULL) {
key->type = KEY_RSA; /* cheat for key_to_blob */
if (key_to_blob(key, &blob, &blen) == 0)
fatal("%s: key_to_blob failed", __func__);
buffer_put_string(m, blob, blen);
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = blen;
key_blobtype = MM_RSAUSERKEY;
}
if (key != NULL)
key_free(key);
mm_request_send(sock, MONITOR_ANS_RSAKEYALLOWED, m);
monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
return (0);
}
int
mm_answer_pam_account(int sock, Buffer *m)
{
u_int ret;
if (!options.use_pam)
fatal("%s: PAM not enabled", __func__);
ret = do_pam_account();
buffer_put_int(m, ret);
buffer_put_string(m, buffer_ptr(&loginmsg), buffer_len(&loginmsg));
mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
return (ret);
}
char *mm_auth2_read_banner(void)
{
Buffer m;
char *banner;
debug3("%s entering", __func__);
buffer_init(&m);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m);
buffer_clear(&m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTH2_READ_BANNER, &m);
banner = buffer_get_string(&m, NULL);
buffer_free(&m);
return (banner);
}
int
mm_answer_pam_free_ctx(int sock, Buffer *m)
{
int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt;
debug3("%s", __func__);
if (sshpam_ctxt == NULL)
fatal("%s: no context", __func__);
(sshpam_device.free_ctx)(sshpam_ctxt);
sshpam_ctxt = sshpam_authok = NULL;
buffer_clear(m);
mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
/* Allow another attempt */
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
auth_method = "keyboard-interactive";
auth_submethod = "pam";
return r;
}
OM_uint32
mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
{
Buffer m;
OM_uint32 major;
buffer_init(&m);
buffer_put_string(&m, gssbuf->value, gssbuf->length);
buffer_put_string(&m, gssmic->value, gssmic->length);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
&m);
major = buffer_get_int(&m);
buffer_free(&m);
return(major);
}
int
mm_answer_gss_userok(int sock, Buffer *m)
{
int authenticated;
authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
buffer_clear(m);
buffer_put_int(m, authenticated);
debug3("%s: sending result %d", __func__, authenticated);
mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
auth_method = "gssapi-with-mic";
/* Monitor loop will terminate if authenticated */
return (authenticated);
}
int
mm_ssh_gssapi_userok(char *user)
{
Buffer m;
int authenticated = 0;
buffer_init(&m);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
&m);
authenticated = buffer_get_int(&m);
buffer_free(&m);
debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
return (authenticated);
}
int
mm_answer_pam_init_ctx(int sock, Buffer *m)
{
debug3("%s", __func__);
authctxt->user = buffer_get_string(m, NULL);
sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
sshpam_authok = NULL;
buffer_clear(m);
if (sshpam_ctxt != NULL) {
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
buffer_put_int(m, 1);
} else {
buffer_put_int(m, 0);
}
mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
return (0);
}
int
mm_answer_jpake_step1(int sock, Buffer *m)
{
struct jpake_ctx *pctx;
u_char *x3_proof, *x4_proof;
u_int x3_proof_len, x4_proof_len;
if (!options.zero_knowledge_password_authentication)
fatal("zero_knowledge_password_authentication disabled");
if (authctxt->jpake_ctx != NULL)
fatal("%s: authctxt->jpake_ctx already set (%p)",
__func__, authctxt->jpake_ctx);
authctxt->jpake_ctx = pctx = jpake_new();
jpake_step1(pctx->grp,
&pctx->server_id, &pctx->server_id_len,
&pctx->x3, &pctx->x4, &pctx->g_x3, &pctx->g_x4,
&x3_proof, &x3_proof_len,
&x4_proof, &x4_proof_len);
JPAKE_DEBUG_CTX((pctx, "step1 done in %s", __func__));
buffer_clear(m);
buffer_put_string(m, pctx->server_id, pctx->server_id_len);
buffer_put_bignum2(m, pctx->g_x3);
buffer_put_bignum2(m, pctx->g_x4);
buffer_put_string(m, x3_proof, x3_proof_len);
buffer_put_string(m, x4_proof, x4_proof_len);
debug3("%s: sending step1", __func__);
mm_request_send(sock, MONITOR_ANS_JPAKE_STEP1, m);
bzero(x3_proof, x3_proof_len);
bzero(x4_proof, x4_proof_len);
xfree(x3_proof);
xfree(x4_proof);
monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_GET_PWDATA, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_JPAKE_STEP1, 0);
return 0;
}
int
mm_answer_rsa_response(int sock, Buffer *m)
{
Key *key = NULL;
u_char *blob, *response;
u_int blen, len;
int success;
debug3("%s entering", __func__);
if (!authctxt->valid)
fatal("%s: authctxt not valid", __func__);
if (ssh1_challenge == NULL)
fatal("%s: no ssh1_challenge", __func__);
blob = buffer_get_string(m, &blen);
if (!monitor_allowed_key(blob, blen))
fatal("%s: bad key, not previously allowed", __func__);
if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
fatal("%s: key type mismatch: %d", __func__, key_blobtype);
if ((key = key_from_blob(blob, blen)) == NULL)
fatal("%s: received bad key", __func__);
response = buffer_get_string(m, &len);
if (len != 16)
fatal("%s: received bad response to challenge", __func__);
success = auth_rsa_verify_response(key, ssh1_challenge, response);
xfree(blob);
key_free(key);
xfree(response);
auth_method = key_blobtype == MM_RSAUSERKEY ? "rsa" : "rhosts-rsa";
/* reset state */
BN_clear_free(ssh1_challenge);
ssh1_challenge = NULL;
monitor_reset_key_state();
buffer_clear(m);
buffer_put_int(m, success);
mm_request_send(sock, MONITOR_ANS_RSARESPONSE, m);
return (success);
}
int
mm_answer_sign(int sock, Buffer *m)
{
Key *key;
u_char *p;
u_char *signature;
u_int siglen, datlen;
int keyid;
debug3("%s", __func__);
keyid = buffer_get_int(m);
p = buffer_get_string(m, &datlen);
if (datlen != 20)
fatal("%s: data length incorrect: %u", __func__, datlen);
/* save session id, it will be passed on the first call */
if (session_id2_len == 0) {
session_id2_len = datlen;
session_id2 = xmalloc(session_id2_len);
memcpy(session_id2, p, session_id2_len);
}
if ((key = get_hostkey_by_index(keyid)) == NULL)
fatal("%s: no hostkey from index %d", __func__, keyid);
if (key_sign(key, &signature, &siglen, p, datlen) < 0)
fatal("%s: key_sign failed", __func__);
debug3("%s: signature %p(%u)", __func__, signature, siglen);
buffer_clear(m);
buffer_put_string(m, signature, siglen);
xfree(p);
xfree(signature);
mm_request_send(sock, MONITOR_ANS_SIGN, m);
/* Turn on permissions for getpwnam */
monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
return (0);
}
int
mm_ssh1_session_key(BIGNUM *num)
{
int rsafail;
Buffer m;
buffer_init(&m);
buffer_put_bignum2(&m, num);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SESSKEY, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SESSKEY, &m);
rsafail = buffer_get_int(&m);
buffer_get_bignum2(&m, num);
buffer_free(&m);
return (rsafail);
}
int
mm_answer_skeyquery(int socket, Buffer *m)
{
struct skey skey;
char challenge[1024];
u_int success;
success = skeychallenge(&skey, authctxt->user, challenge) < 0 ? 0 : 1;
buffer_clear(m);
buffer_put_int(m, success);
if (success)
buffer_put_cstring(m, challenge);
debug3("%s: sending challenge success: %u", __func__, success);
mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m);
return (0);
}
int
mm_answer_skeyquery(int socket, Buffer *m)
{
struct skey skey;
char challenge[1024];
int res;
res = skeychallenge(&skey, authctxt->user, challenge);
buffer_clear(m);
buffer_put_int(m, res);
if (res != -1)
buffer_put_cstring(m, challenge);
debug3("%s: sending challenge res: %d", __func__, res);
mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m);
return (0);
}
int
mm_sshpam_respond(void *ctx, u_int num, char **resp)
{
Buffer m;
int i, ret;
debug3("%s", __func__);
buffer_init(&m);
buffer_put_int(&m, num);
for (i = 0; i < num; ++i)
buffer_put_cstring(&m, resp[i]);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_RESPOND, &m);
debug3("%s: waiting for MONITOR_ANS_PAM_RESPOND", __func__);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_RESPOND, &m);
ret = buffer_get_int(&m);
debug3("%s: pam_respond returned %d", __func__, ret);
buffer_free(&m);
return (ret);
}
int
mm_answer_gss_userok(int sock, struct sshbuf *m)
{
int r, authenticated;
authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, authenticated)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
debug3("%s: sending result %d", __func__, authenticated);
mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
auth_method = "gssapi-with-mic";
/* Monitor loop will terminate if authenticated */
return (authenticated);
}
int
mm_answer_krb4(int socket, Buffer *m)
{
KTEXT_ST auth, reply;
char *client, *p;
int success;
u_int alen;
reply.length = auth.length = 0;
p = buffer_get_string(m, &alen);
if (alen >= MAX_KTXT_LEN)
fatal("%s: auth too large", __func__);
memcpy(auth.dat, p, alen);
auth.length = alen;
memset(p, 0, alen);
xfree(p);
success = options.kerberos_authentication &&
authctxt->valid &&
auth_krb4(authctxt, &auth, &client, &reply);
memset(auth.dat, 0, alen);
buffer_clear(m);
buffer_put_int(m, success);
if (success) {
buffer_put_cstring(m, client);
buffer_put_string(m, reply.dat, reply.length);
if (client)
xfree(client);
if (reply.length)
memset(reply.dat, 0, reply.length);
}
debug3("%s: sending result %d", __func__, success);
mm_request_send(socket, MONITOR_ANS_KRB4, m);
auth_method = "kerberos";
/* Causes monitor loop to terminate if authenticated */
return (success);
}
OM_uint32
mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
{
Buffer m;
OM_uint32 major;
/* Client doesn't get to see the context */
*ctx = NULL;
buffer_init(&m);
buffer_put_string(&m, goid->elements, goid->length);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);
major = buffer_get_int(&m);
buffer_free(&m);
return (major);
}
void *
mm_sshpam_init_ctx(Authctxt *authctxt)
{
Buffer m;
int success;
debug3("%s", __func__);
buffer_init(&m);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PAM_INIT_CTX, &m);
debug3("%s: waiting for MONITOR_ANS_PAM_INIT_CTX", __func__);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PAM_INIT_CTX, &m);
success = buffer_get_int(&m);
if (success == 0) {
debug3("%s: pam_init_ctx failed", __func__);
buffer_free(&m);
return (NULL);
}
buffer_free(&m);
return (authctxt);
}
void
mm_session_pty_cleanup2(Session *s)
{
Buffer m;
if (s->ttyfd == -1)
return;
buffer_init(&m);
buffer_put_cstring(&m, s->tty);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
buffer_free(&m);
/* closed dup'ed master */
if (s->ptymaster != -1 && close(s->ptymaster) < 0)
error("close(s->ptymaster/%d): %s",
s->ptymaster, strerror(errno));
/* unlink pty from session */
s->ttyfd = -1;
}
int
mm_answer_pam_init_ctx(int sock, Buffer *m)
{
debug3("%s", __func__);
if (!options.kbd_interactive_authentication)
fatal("%s: kbd-int authentication not enabled", __func__);
if (sshpam_ctxt != NULL)
fatal("%s: already called", __func__);
sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
sshpam_authok = NULL;
buffer_clear(m);
if (sshpam_ctxt != NULL) {
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_PAM_QUERY, 1);
buffer_put_int(m, 1);
} else {
buffer_put_int(m, 0);
}
mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
return (0);
}
OM_uint32
mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash)
{
Buffer m;
OM_uint32 major;
u_int len;
buffer_init(&m);
buffer_put_string(&m, data->value, data->length);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m);
major = buffer_get_int(&m);
hash->value = buffer_get_string(&m, &len);
hash->length = len;
buffer_free(&m);
return(major);
}
int
mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store)
{
Buffer m;
int ok;
buffer_init(&m);
buffer_put_cstring(&m, store->filename ? store->filename : "");
buffer_put_cstring(&m, store->envvar ? store->envvar : "");
buffer_put_cstring(&m, store->envval ? store->envval : "");
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m);
ok = buffer_get_int(&m);
buffer_free(&m);
return (ok);
}
int
mm_key_sign(Key *key, u_char **sigp, u_int *lenp, u_char *data, u_int datalen)
{
Kex *kex = *pmonitor->m_pkex;
Buffer m;
debug3("%s entering", __func__);
buffer_init(&m);
buffer_put_int(&m, kex->host_key_index(key));
buffer_put_string(&m, data, datalen);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m);
debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, &m);
*sigp = buffer_get_string(&m, lenp);
buffer_free(&m);
return (0);
}
void
mm_auth2_jpake_get_pwdata(Authctxt *authctxt, BIGNUM **s,
char **hash_scheme, char **salt)
{
Buffer m;
debug3("%s entering", __func__);
buffer_init(&m);
mm_request_send(pmonitor->m_recvfd,
MONITOR_REQ_JPAKE_GET_PWDATA, &m);
debug3("%s: waiting for MONITOR_ANS_JPAKE_GET_PWDATA", __func__);
mm_request_receive_expect(pmonitor->m_recvfd,
MONITOR_ANS_JPAKE_GET_PWDATA, &m);
*hash_scheme = buffer_get_string(&m, NULL);
*salt = buffer_get_string(&m, NULL);
buffer_free(&m);
}
int
mm_answer_rsa_challenge(int sock, struct sshbuf *m)
{
struct sshkey *key = NULL;
u_char *blob;
size_t blen;
int r;
debug3("%s entering", __func__);
if (!authctxt->valid)
fatal("%s: authctxt not valid", __func__);
if ((r = sshbuf_get_string(m, &blob, &blen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (!monitor_allowed_key(blob, blen))
fatal("%s: bad key, not previously allowed", __func__);
if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
fatal("%s: key type mismatch", __func__);
if ((r = sshkey_from_blob(blob, blen, &key)) != 0)
fatal("%s: received bad key: %s", __func__, ssh_err(r));
if (key->type != KEY_RSA)
fatal("%s: received bad key type %d", __func__, key->type);
key->type = KEY_RSA1;
if (ssh1_challenge)
BN_clear_free(ssh1_challenge);
ssh1_challenge = auth_rsa_generate_challenge(key);
sshbuf_reset(m);
if ((r = sshbuf_put_bignum2(m, ssh1_challenge)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
debug3("%s sending reply", __func__);
mm_request_send(sock, MONITOR_ANS_RSACHALLENGE, m);
monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
free(blob);
sshkey_free(key);
return (0);
}
int
mm_skey_query(void *ctx, char **name, char **infotxt,
u_int *numprompts, char ***prompts, u_int **echo_on)
{
Buffer m;
int len;
u_int success;
char *p, *challenge;
debug3("%s: entering", __func__);
buffer_init(&m);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SKEYQUERY, &m);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SKEYQUERY,
&m);
success = buffer_get_int(&m);
if (success == 0) {
debug3("%s: no challenge", __func__);
buffer_free(&m);
return (-1);
}
/* Get the challenge, and format the response */
challenge = buffer_get_string(&m, NULL);
buffer_free(&m);
debug3("%s: received challenge: %s", __func__, challenge);
mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
len = strlen(challenge) + strlen(SKEY_PROMPT) + 1;
p = xmalloc(len);
strlcpy(p, challenge, len);
strlcat(p, SKEY_PROMPT, len);
(*prompts)[0] = p;
xfree(challenge);
return (0);
}
int
mm_key_allowed(enum mm_keytype type, char *user, char *host, Key *key)
{
Buffer m;
u_char *blob;
u_int len;
int allowed = 0, have_forced = 0;
debug3("%s entering", __func__);
/* Convert the key to a blob and the pass it over */
if (!key_to_blob(key, &blob, &len))
return (0);
buffer_init(&m);
buffer_put_int(&m, type);
buffer_put_cstring(&m, user ? user : "");
buffer_put_cstring(&m, host ? host : "");
buffer_put_string(&m, blob, len);
xfree(blob);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m);
debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m);
allowed = buffer_get_int(&m);
/* fake forced command */
auth_clear_options();
have_forced = buffer_get_int(&m);
forced_command = have_forced ? xstrdup("true") : NULL;
/* Send potential debug messages */
mm_send_debug(&m);
buffer_free(&m);
return (allowed);
}
int
mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
{
Buffer m;
int authok;
debug3("%s: entering", __func__);
if (numresponses != 1)
return (-1);
buffer_init(&m);
buffer_put_cstring(&m, responses[0]);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);
mm_request_receive_expect(pmonitor->m_recvfd,
MONITOR_ANS_BSDAUTHRESPOND, &m);
authok = buffer_get_int(&m);
buffer_free(&m);
return ((authok == 0) ? -1 : 0);
}
void
mm_jpake_step2(struct modp_group *grp, BIGNUM *s,
BIGNUM *mypub1, BIGNUM *theirpub1, BIGNUM *theirpub2, BIGNUM *mypriv2,
const u_char *theirid, u_int theirid_len,
const u_char *myid, u_int myid_len,
const u_char *theirpub1_proof, u_int theirpub1_proof_len,
const u_char *theirpub2_proof, u_int theirpub2_proof_len,
BIGNUM **newpub,
u_char **newpub_exponent_proof, u_int *newpub_exponent_proof_len)
{
Buffer m;
debug3("%s entering", __func__);
buffer_init(&m);
/* monitor already has all bignums except theirpub1, theirpub2 */
buffer_put_bignum2(&m, theirpub1);
buffer_put_bignum2(&m, theirpub2);
/* monitor already knows our id */
buffer_put_string(&m, theirid, theirid_len);
buffer_put_string(&m, theirpub1_proof, theirpub1_proof_len);
buffer_put_string(&m, theirpub2_proof, theirpub2_proof_len);
mm_request_send(pmonitor->m_recvfd,
MONITOR_REQ_JPAKE_STEP2, &m);
debug3("%s: waiting for MONITOR_ANS_JPAKE_STEP2", __func__);
mm_request_receive_expect(pmonitor->m_recvfd,
MONITOR_ANS_JPAKE_STEP2, &m);
if ((*newpub = BN_new()) == NULL)
fatal("%s: BN_new", __func__);
buffer_get_bignum2(&m, *newpub);
*newpub_exponent_proof = buffer_get_string(&m,
newpub_exponent_proof_len);
buffer_free(&m);
}
