/*
* Filters a proposal string, excluding any algorithm matching the 'filter'
* pattern list.
*/
static char *
filter_proposal(char *proposal, const char *filter)
{
char *orig_prop, *fix_prop;
char *cp, *tmp;
size_t maxlen;
tmp = orig_prop = strdup(proposal);
if (!tmp)
return NULL;
maxlen = strlen(orig_prop) + 1;
if ((fix_prop = calloc(1, maxlen)) == NULL) {
free(orig_prop);
return NULL;
}
while ((cp = strsep(&tmp, ",")) != NULL) {
if (match_pattern_list(cp, filter, strlen(cp), 0) != 1) {
if (*fix_prop != '\0')
strlcat(fix_prop, ",", maxlen);
strlcat(fix_prop, cp, maxlen);
} else
debug2("Compat: skipping algorithm \"%s\"", cp);
}
free(orig_prop);
return fix_prop;
}
/*
* Determine whether the filesystem @path should be excluded from capture, based
* on the current capture configuration file.
*
* The @path must be given relative to the root of the capture, but with a
* leading path separator. For example, if the file "in/file" is being tested
* and the library user ran wimlib_add_image(wim, "in", ...), then the directory
* "in" is the root of the capture and the path should be specified as "/file".
*
* Also, all path separators in @path must be OS_PREFERRED_PATH_SEPARATOR, there
* cannot be trailing slashes, and there cannot be consecutive path separators.
*
* As a special case, the empty string will be interpreted as a single path
* separator (which means the root of capture itself).
*/
static bool
should_exclude_path(const tchar *path, size_t path_nchars,
const struct capture_config *config)
{
tchar dummy[2];
if (!config)
return false;
if (!*path) {
dummy[0] = OS_PREFERRED_PATH_SEPARATOR;
dummy[1] = T('\0');
path = dummy;
path_nchars = 1;
}
return match_pattern_list(path, path_nchars, &config->exclusion_pats) &&
!match_pattern_list(path, path_nchars, &config->exclusion_exception_pats);
}
static OpCodes
parse_token(const char *cp, const char *filename, int linenum,
const char *ignored_unknown)
{
int i;
for (i = 0; keywords[i].name; i++)
if (strcmp(cp, keywords[i].name) == 0)
return keywords[i].opcode;
if (ignored_unknown != NULL && match_pattern_list(cp, ignored_unknown,
strlen(ignored_unknown), 1) == 1)
return oIgnoredUnknownOption;
error("%s: line %d: Bad configuration option: %s",
filename, linenum, cp);
return oBadOption;
}
/*
* Return 1 if one of user's groups matches group_pattern list.
* Return 0 on negated or no match.
*/
int
ga_match_pattern_list(const char *group_pattern)
{
int i, found = 0;
for (i = 0; i < ngroups; i++) {
switch (match_pattern_list(groups_byname[i], group_pattern, 0)) {
case -1:
return 0; /* Negated match wins */
case 0:
continue;
case 1:
found = 1;
}
}
return found;
}
/*
* Filters a proposal string, excluding any algorithm matching the 'filter'
* pattern list.
*/
static char *
filter_proposal(char *proposal, const char *filter)
{
Buffer b;
char *orig_prop, *fix_prop;
char *cp, *tmp;
buffer_init(&b);
tmp = orig_prop = xstrdup(proposal);
while ((cp = strsep(&tmp, ",")) != NULL) {
if (match_pattern_list(cp, filter, 0) != 1) {
if (buffer_len(&b) > 0)
buffer_append(&b, ",", 1);
buffer_append(&b, cp, strlen(cp));
} else
debug2("Compat: skipping algorithm \"%s\"", cp);
}
buffer_append(&b, "\0", 1);
fix_prop = xstrdup((char *)buffer_ptr(&b));
buffer_free(&b);
free(orig_prop);
return fix_prop;
}
static int
match_cfg_line(char **condition, int line, const char *user, const char *host,
const char *address)
{
int result = 1;
char *arg, *attrib, *cp = *condition;
size_t len;
if (user == NULL)
debug3("checking syntax for 'Match %s'", cp);
else
debug3("checking match for '%s' user %s host %s addr %s", cp,
user ? user : "******", host ? host : "(null)",
address ? address : "(null)");
while ((attrib = strdelim(&cp)) && *attrib != '\0') {
if ((arg = strdelim(&cp)) == NULL || *arg == '\0') {
error("Missing Match criteria for %s", attrib);
return -1;
}
len = strlen(arg);
if (strcasecmp(attrib, "user") == 0) {
if (!user) {
result = 0;
continue;
}
if (match_pattern_list(user, arg, len, 0) != 1)
result = 0;
else
debug("user %.100s matched 'User %.100s' at "
"line %d", user, arg, line);
} else if (strcasecmp(attrib, "group") == 0) {
switch (match_cfg_line_group(arg, line, user)) {
case -1:
return -1;
case 0:
result = 0;
}
} else if (strcasecmp(attrib, "host") == 0) {
if (!host) {
result = 0;
continue;
}
if (match_hostname(host, arg, len) != 1)
result = 0;
else
debug("connection from %.100s matched 'Host "
"%.100s' at line %d", host, arg, line);
} else if (strcasecmp(attrib, "address") == 0) {
switch (addr_match_list(address, arg)) {
case 1:
debug("connection from %.100s matched 'Address "
"%.100s' at line %d", address, arg, line);
break;
case 0:
case -1:
result = 0;
break;
case -2:
return -1;
}
} else {
error("Unsupported Match attribute %s", attrib);
return -1;
}
}
if (user != NULL)
debug3("match %sfound", result ? "" : "not ");
*condition = cp;
return result;
}
/* datafellows bug compatibility */
void
compat_datafellows(const char *version)
{
int i;
static struct {
const char *pat;
int bugs;
} check[] = {
{ "OpenSSH-2.0*,"
"OpenSSH-2.1*,"
"OpenSSH_2.1*,"
"OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER|
SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.0p1*,"
"OpenSSH_2.5.1p1*",
SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.0*,"
"OpenSSH_2.5.1*,"
"OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.*,"
"OpenSSH_3.0*,"
"OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR },
{ "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
{ "OpenSSH_4*", 0 },
{ "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT},
{ "OpenSSH*", SSH_NEW_OPENSSH },
{ "*MindTerm*", 0 },
{ "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
SSH_BUG_FIRSTKEX },
{ "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
SSH_BUG_FIRSTKEX },
{ "2.0.13*,"
"2.0.14*,"
"2.0.15*,"
"2.0.16*,"
"2.0.17*,"
"2.0.18*,"
"2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
{ "2.0.11*,"
"2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKAUTH|SSH_BUG_PKOK|
SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
{ "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKAUTH|SSH_BUG_PKOK|
SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
SSH_BUG_FIRSTKEX },
{ "2.2.0*,"
"2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
{ "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
SSH_BUG_FIRSTKEX },
{ "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */
{ "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
SSH_BUG_RFWD_ADDR },
{ "3.0.*", SSH_BUG_DEBUG },
{ "3.0 SecureCRT*", SSH_OLD_SESSIONID },
{ "1.7 SecureFX*", SSH_OLD_SESSIONID },
{ "1.2.18*,"
"1.2.19*,"
"1.2.20*,"
"1.2.21*,"
"1.2.22*", SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
{ "1.3.2*", /* F-Secure */
SSH_BUG_IGNOREMSG|SSH_BUG_K5USER },
{ "1.2.1*,"
"1.2.2*,"
"1.2.3*", SSH_BUG_K5USER },
{ "*SSH Compatible Server*", /* Netscreen */
SSH_BUG_PASSWORDPAD },
{ "*OSU_0*,"
"OSU_1.0*,"
"OSU_1.1*,"
"OSU_1.2*,"
"OSU_1.3*,"
"OSU_1.4*,"
"OSU_1.5alpha1*,"
"OSU_1.5alpha2*,"
"OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
{ "*SSH_Version_Mapper*",
SSH_BUG_SCANNER },
{ "Probe-*",
SSH_BUG_PROBE },
{ NULL, 0 }
};
/* process table, return first match */
for (i = 0; check[i].pat; i++) {
if (match_pattern_list(version, check[i].pat,
strlen(check[i].pat), 0) == 1) {
debug("match: %s pat %s", version, check[i].pat);
datafellows = check[i].bugs;
/* Check to see if the remote side is OpenSSH and not HPN */
if(strstr(version,"OpenSSH") != NULL)
{
if (strstr(version,"hpn") == NULL)
{
datafellows |= SSH_BUG_LARGEWINDOW;
debug("Remote is NON-HPN aware");
}
}
return;
}
}
debug("no match: %s", version);
}
/* datafellows bug compatibility */
void
openssh_compat_datafellows(ncrack_ssh_state *nstate)
{
int i;
static struct {
char *pat;
int bugs;
} check[] = {
{ "OpenSSH-2.0*,"
"OpenSSH-2.1*,"
"OpenSSH_2.1*,"
"OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER|
SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.0p1*,"
"OpenSSH_2.5.1p1*",
SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.0*,"
"OpenSSH_2.5.1*,"
"OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.*,"
"OpenSSH_3.0*,"
"OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR },
{ "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
{ "OpenSSH_4*", 0 },
{ "OpenSSH*", SSH_NEW_OPENSSH },
{ "*MindTerm*", 0 },
{ "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
SSH_BUG_FIRSTKEX },
{ "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
SSH_BUG_FIRSTKEX },
{ "2.0.13*,"
"2.0.14*,"
"2.0.15*,"
"2.0.16*,"
"2.0.17*,"
"2.0.18*,"
"2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
{ "2.0.11*,"
"2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKAUTH|SSH_BUG_PKOK|
SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
{ "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKAUTH|SSH_BUG_PKOK|
SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
SSH_BUG_FIRSTKEX },
{ "2.2.0*,"
"2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
{ "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
SSH_BUG_FIRSTKEX },
{ "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */
{ "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
SSH_BUG_RFWD_ADDR },
{ "3.0.*", SSH_BUG_DEBUG },
{ "3.0 SecureCRT*", SSH_OLD_SESSIONID },
{ "1.7 SecureFX*", SSH_OLD_SESSIONID },
{ "1.2.18*,"
"1.2.19*,"
"1.2.20*,"
"1.2.21*,"
"1.2.22*", SSH_BUG_IGNOREMSG },
{ "1.3.2*", /* F-Secure */
SSH_BUG_IGNOREMSG },
{ "*SSH Compatible Server*", /* Netscreen */
SSH_BUG_PASSWORDPAD },
{ "*OSU_0*,"
"OSU_1.0*,"
"OSU_1.1*,"
"OSU_1.2*,"
"OSU_1.3*,"
"OSU_1.4*,"
"OSU_1.5alpha1*,"
"OSU_1.5alpha2*,"
"OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
{ "*SSH_Version_Mapper*",
SSH_BUG_SCANNER },
{ "Probe-*",
SSH_BUG_PROBE },
{ NULL, 0 }
};
/* process table, return first match */
for (i = 0; check[i].pat; i++) {
if (match_pattern_list(nstate->server_version_string, check[i].pat,
strlen(check[i].pat), 0) == 1) {
debug("match: %s pat %s", nstate->server_version_string, check[i].pat);
nstate->datafellows = check[i].bugs;
return;
}
}
debug("no match: %s", nstate->server_version_string);
}
static int
userauth_pubkey(Authctxt *authctxt)
{
#ifdef WIN32_FIXME
int loginStat = 1;
char currentUser[MAX_PATH] = {0};
DWORD currentUserSize = sizeof(currentUser);
int targetIsCurrent = 0;
# ifdef USE_NTCREATETOKEN
int doOpenSSHVerify = 1;
# else
int doOpenSSHVerify = 0;
# endif
#endif
Buffer b;
Key *key = NULL;
char *pkalg, *userstyle;
u_char *pkblob, *sig;
u_int alen, blen, slen;
int have_sig, pktype;
int authenticated = 0;
if (!authctxt->valid) {
debug2("userauth_pubkey: disabled because of invalid user");
return 0;
}
have_sig = packet_get_char();
if (datafellows & SSH_BUG_PKAUTH) {
debug2("userauth_pubkey: SSH_BUG_PKAUTH");
/* no explicit pkalg given */
pkblob = packet_get_string(&blen);
buffer_init(&b);
buffer_append(&b, pkblob, blen);
/* so we have to extract the pkalg from the pkblob */
pkalg = buffer_get_string(&b, &alen);
buffer_free(&b);
} else {
pkalg = packet_get_string(&alen);
pkblob = packet_get_string(&blen);
}
pktype = key_type_from_name(pkalg);
if (pktype == KEY_UNSPEC) {
/* this is perfectly legal */
logit("userauth_pubkey: unsupported public key algorithm: %s",
pkalg);
goto done;
}
key = key_from_blob(pkblob, blen);
if (key == NULL) {
error("userauth_pubkey: cannot decode key: %s", pkalg);
goto done;
}
if (key->type != pktype) {
error("userauth_pubkey: type mismatch for decoded key "
"(received %d, expected %d)", key->type, pktype);
goto done;
}
if (key_type_plain(key->type) == KEY_RSA &&
(datafellows & SSH_BUG_RSASIGMD5) != 0) {
logit("Refusing RSA key because client uses unsafe "
"signature scheme");
goto done;
}
if (auth2_userkey_already_used(authctxt, key)) {
logit("refusing previously-used %s key", key_type(key));
goto done;
}
if (match_pattern_list(sshkey_ssh_name(key),
options.pubkey_key_types, 0) != 1) {
logit("%s: key type %s not in PubkeyAcceptedKeyTypes",
__func__, sshkey_ssh_name(key));
goto done;
}
if (have_sig) {
sig = packet_get_string(&slen);
packet_check_eom();
buffer_init(&b);
if (datafellows & SSH_OLD_SESSIONID) {
buffer_append(&b, session_id2, session_id2_len);
} else {
buffer_put_string(&b, session_id2, session_id2_len);
}
/* reconstruct packet */
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
buffer_put_cstring(&b, userstyle);
free(userstyle);
buffer_put_cstring(&b,
datafellows & SSH_BUG_PKSERVICE ?
"ssh-userauth" :
authctxt->service);
if (datafellows & SSH_BUG_PKAUTH) {
buffer_put_char(&b, have_sig);
} else {
buffer_put_cstring(&b, "publickey");
buffer_put_char(&b, have_sig);
buffer_put_cstring(&b, pkalg);
}
buffer_put_string(&b, pkblob, blen);
#ifdef DEBUG_PK
buffer_dump(&b);
#endif
pubkey_auth_info(authctxt, key, NULL);
/* test for correct signature */
authenticated = 0;
/*
* On pure win32 try to logon using lsa first.
*/
#ifdef WIN32_FIXME
authctxt -> hTokenLsa_ = NULL;
authctxt -> methoddata = NULL;
/*
* Retrieve name of current login user (i.e. sshd process owner).
*/
GetUserName(currentUser, ¤tUserSize);
/*
* Try to get token from lsa, but only if targetUser != currentUser.
* Owerthise we already have targetUser's token in current thread, so
* we only need key verify from original OpenSSH code.
*/
targetIsCurrent = (strcmp(currentUser, authctxt -> user) == 0);
if (targetIsCurrent)
{
doOpenSSHVerify = 1;
}
else
{
loginStat = LsaLogon(&authctxt -> hTokenLsa_, HomeDirLsaW,
authctxt -> user, pkblob, blen, sig, slen,
buffer_ptr(&b), buffer_len(&b), datafellows);
/*
* If lsa logon process success.
*/
if (loginStat == 0)
{
/*
* And user authorized OK.
*/
if (authctxt -> hTokenLsa_)
{
doOpenSSHVerify = 0;
/*
* This is part of openssh authorization needed for parsing
* 'options' block in key.
*/
authctxt -> pw -> pw_dir = GetHomeDir(authctxt -> user);
if (PRIVSEP(user_key_allowed(authctxt -> pw, key, 1))) // PRAGMA:TODO
{
authenticated = 1;
}
else
{
authenticated = 0;
}
buffer_free(&b);
free(sig);
}
}
}
if (doOpenSSHVerify)
{
/*
* If lsa fails, test for correct signature using openssh code.
*/
authctxt -> pw -> pw_dir = GetHomeDir(authctxt -> user);
if (PRIVSEP(user_key_allowed(authctxt->pw, key, 0)) //PRAGMA:TODO
&&
PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b))) == 1)
{
authenticated = 1;
}
}
/*
* Original code.
*/
#else /* #ifdef WIN32_FIXME */
if (PRIVSEP(user_key_allowed(authctxt->pw, key, 1)) &&
PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
buffer_len(&b))) == 1) {
authenticated = 1;
/* Record the successful key to prevent reuse */
auth2_record_userkey(authctxt, key);
key = NULL; /* Don't free below */
}
buffer_free(&b);
free(sig);
#endif /* else #ifdef WIN32_FIXME. */
} else {
debug("test whether pkalg/pkblob are acceptable");
packet_check_eom();
/* XXX fake reply and always send PK_OK ? */
/*
* XXX this allows testing whether a user is allowed
* to login: if you happen to have a valid pubkey this
* message is sent. the message is NEVER sent at all
* if a user is not allowed to login. is this an
* issue? -markus
*/
#ifndef WIN32_FIXME
if (PRIVSEP(user_key_allowed(authctxt->pw, key, 0)))
#endif
{
packet_start(SSH2_MSG_USERAUTH_PK_OK);
packet_put_string(pkalg, alen);
packet_put_string(pkblob, blen);
packet_send();
packet_write_wait();
authctxt->postponed = 1;
}
}
if (authenticated != 1)
auth_clear_options();
done:
debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
if (key != NULL)
key_free(key);
free(pkalg);
free(pkblob);
return authenticated;
}
int
mm_answer_keyallowed(int sock, struct sshbuf *m)
{
struct ssh *ssh = active_state; /* XXX */
struct sshkey *key;
char *cuser, *chost;
u_char *blob;
size_t bloblen;
enum mm_keytype type = 0;
int r, allowed = 0;
debug3("%s entering", __func__);
if ((r = sshbuf_get_u32(m, &type)) != 0 ||
(r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 ||
(r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
(r = sshbuf_get_string(m, &blob, &bloblen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
fatal("%s: cannot parse key: %s", __func__, ssh_err(r));
if ((compat20 && type == MM_RSAHOSTKEY) ||
(!compat20 && type != MM_RSAHOSTKEY))
fatal("%s: key type and protocol mismatch", __func__);
if (key != NULL && authctxt->valid) {
/* These should not make it past the privsep child */
if (sshkey_type_plain(key->type) == KEY_RSA &&
(ssh->compat & SSH_BUG_RSASIGMD5) != 0)
fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
switch (type) {
case MM_USERKEY:
allowed = options.pubkey_authentication &&
!auth2_userkey_already_used(authctxt, key) &&
match_pattern_list(sshkey_ssh_name(key),
options.pubkey_key_types,
strlen(options.pubkey_key_types), 0) == 1 &&
user_key_allowed(authctxt->pw, key);
pubkey_auth_info(authctxt, key, NULL);
auth_method = "publickey";
if (options.pubkey_authentication && allowed != 1)
auth_clear_options();
break;
case MM_HOSTKEY:
allowed = options.hostbased_authentication &&
match_pattern_list(sshkey_ssh_name(key),
options.hostbased_key_types,
strlen(options.hostbased_key_types), 0) == 1 &&
hostbased_key_allowed(authctxt->pw,
cuser, chost, key);
pubkey_auth_info(authctxt, key,
"client user \"%.100s\", client host \"%.100s\"",
cuser, chost);
auth_method = "hostbased";
break;
#ifdef WITH_SSH1
case MM_RSAHOSTKEY:
key->type = KEY_RSA1; /* XXX */
allowed = options.rhosts_rsa_authentication &&
auth_rhosts_rsa_key_allowed(authctxt->pw,
cuser, chost, key);
if (options.rhosts_rsa_authentication && allowed != 1)
auth_clear_options();
auth_method = "rsa";
break;
#endif
default:
fatal("%s: unknown key type %d", __func__, type);
break;
}
}
if (key != NULL)
sshkey_free(key);
/* clear temporarily storage (used by verify) */
monitor_reset_key_state();
if (allowed) {
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = bloblen;
key_blobtype = type;
hostbased_cuser = cuser;
hostbased_chost = chost;
} else {
/* Log failed attempt */
auth_log(authctxt, 0, 0, auth_method, NULL);
free(blob);
free(cuser);
free(chost);
}
debug3("%s: key %p is %s",
__func__, key, allowed ? "allowed" : "not allowed");
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, allowed)) != 0 ||
(r = sshbuf_put_u32(m, forced_command != NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
if (type == MM_RSAHOSTKEY)
monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
return (0);
}
/* datafellows bug compatibility */
u_int
ncrackssh_compat_datafellows(ncrack_ssh_state *nstate)
{
int i;
static struct {
char *pat;
int bugs;
} check[] = {
{ "OpenSSH-2.0*,"
"OpenSSH-2.1*,"
"OpenSSH_2.1*,"
"OpenSSH_2.2*", SSH_OLD_SESSIONID|SSH_BUG_BANNER|
SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.3.0*", SSH_BUG_BANNER|SSH_BUG_BIGENDIANAES|
SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.3.*", SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.0p1*,"
"OpenSSH_2.5.1p1*",
SSH_BUG_BIGENDIANAES|SSH_OLD_DHGEX|
SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.0*,"
"OpenSSH_2.5.1*,"
"OpenSSH_2.5.2*", SSH_OLD_DHGEX|SSH_BUG_NOREKEY|
SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_2.*,"
"OpenSSH_3.0*,"
"OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR},
{ "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR },
{ "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF},
{ "OpenSSH_4*", 0 },
{ "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT},
{ "OpenSSH_6.6.1*", SSH_NEW_OPENSSH},
{ "OpenSSH_6.5*,"
"OpenSSH_6.6*", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD},
{ "OpenSSH*", SSH_NEW_OPENSSH },
{ "*MindTerm*", 0 },
{ "2.1.0*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
SSH_BUG_FIRSTKEX },
{ "2.1 *", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_HBSERVICE|
SSH_BUG_FIRSTKEX },
{ "2.0.13*,"
"2.0.14*,"
"2.0.15*,"
"2.0.16*,"
"2.0.17*,"
"2.0.18*,"
"2.0.19*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKOK|SSH_BUG_RSASIGMD5|
SSH_BUG_HBSERVICE|SSH_BUG_OPENFAILURE|
SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
{ "2.0.11*,"
"2.0.12*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKAUTH|SSH_BUG_PKOK|
SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
SSH_BUG_DUMMYCHAN|SSH_BUG_FIRSTKEX },
{ "2.0.*", SSH_BUG_SIGBLOB|SSH_BUG_HMAC|
SSH_OLD_SESSIONID|SSH_BUG_DEBUG|
SSH_BUG_PKSERVICE|SSH_BUG_X11FWD|
SSH_BUG_PKAUTH|SSH_BUG_PKOK|
SSH_BUG_RSASIGMD5|SSH_BUG_OPENFAILURE|
SSH_BUG_DERIVEKEY|SSH_BUG_DUMMYCHAN|
SSH_BUG_FIRSTKEX },
{ "2.2.0*,"
"2.3.0*", SSH_BUG_HMAC|SSH_BUG_DEBUG|
SSH_BUG_RSASIGMD5|SSH_BUG_FIRSTKEX },
{ "2.3.*", SSH_BUG_DEBUG|SSH_BUG_RSASIGMD5|
SSH_BUG_FIRSTKEX },
{ "2.4", SSH_OLD_SESSIONID }, /* Van Dyke */
{ "2.*", SSH_BUG_DEBUG|SSH_BUG_FIRSTKEX|
SSH_BUG_RFWD_ADDR },
{ "3.0.*", SSH_BUG_DEBUG },
{ "3.0 SecureCRT*", SSH_OLD_SESSIONID },
{ "1.7 SecureFX*", SSH_OLD_SESSIONID },
{ "1.2.18*,"
"1.2.19*,"
"1.2.20*,"
"1.2.21*,"
"1.2.22*", SSH_BUG_IGNOREMSG },
{ "1.3.2*", /* F-Secure */
SSH_BUG_IGNOREMSG },
{ "Cisco-1.*", SSH_BUG_DHGEX_LARGE|
SSH_BUG_HOSTKEYS },
{ "*SSH Compatible Server*", /* Netscreen */
SSH_BUG_PASSWORDPAD },
{ "*OSU_0*,"
"OSU_1.0*,"
"OSU_1.1*,"
"OSU_1.2*,"
"OSU_1.3*,"
"OSU_1.4*,"
"OSU_1.5alpha1*,"
"OSU_1.5alpha2*,"
"OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
{ "*SSH_Version_Mapper*",
SSH_BUG_SCANNER },
{ "PuTTY_Local:*," /* dev versions < Sep 2014 */
"PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */
"PuTTY_Release_0.5*," /* 0.58-0.59 */
"PuTTY_Release_0.60*,"
"PuTTY_Release_0.61*,"
"PuTTY_Release_0.62*,"
"PuTTY_Release_0.63*,"
"PuTTY_Release_0.64*",
SSH_OLD_DHGEX },
{ "FuTTY*", SSH_OLD_DHGEX }, /* Putty Fork */
{ "Probe-*",
SSH_BUG_PROBE },
{ "TeraTerm SSH*,"
"TTSSH/1.5.*,"
"TTSSH/2.1*,"
"TTSSH/2.2*,"
"TTSSH/2.3*,"
"TTSSH/2.4*,"
"TTSSH/2.5*,"
"TTSSH/2.6*,"
"TTSSH/2.70*,"
"TTSSH/2.71*,"
"TTSSH/2.72*", SSH_BUG_HOSTKEYS },
{ "WinSCP_release_4*,"
"WinSCP_release_5.0*,"
"WinSCP_release_5.1*,"
"WinSCP_release_5.5*,"
"WinSCP_release_5.6*,"
"WinSCP_release_5.7,"
"WinSCP_release_5.7.1,"
"WinSCP_release_5.7.2,"
"WinSCP_release_5.7.3,"
"WinSCP_release_5.7.4",
SSH_OLD_DHGEX },
{ NULL, 0 }
};
/* process table, return first match */
for (i = 0; check[i].pat; i++) {
if (match_pattern_list(nstate->server_version_string, check[i].pat, 0) == 1) {
debug("match: %s pat %s compat 0x%08x",
nstate->server_version_string, check[i].pat, check[i].bugs);
nstate->datafellows = check[i].bugs;
return 0;
}
}
debug("no match: %s", nstate->server_version_string);
return 0;
}
static int
userauth_hostbased(struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
struct sshbuf *b;
struct sshkey *key = NULL;
char *pkalg, *cuser, *chost;
u_char *pkblob, *sig;
size_t alen, blen, slen;
int r, pktype, authenticated = 0;
if (!authctxt->valid) {
debug2("%s: disabled because of invalid user", __func__);
return 0;
}
/* XXX use sshkey_froms() */
if ((r = sshpkt_get_cstring(ssh, &pkalg, &alen)) != 0 ||
(r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
(r = sshpkt_get_cstring(ssh, &chost, NULL)) != 0 ||
(r = sshpkt_get_cstring(ssh, &cuser, NULL)) != 0 ||
(r = sshpkt_get_string(ssh, &sig, &slen)) != 0)
fatal("%s: packet parsing: %s", __func__, ssh_err(r));
debug("%s: cuser %s chost %s pkalg %s slen %zu", __func__,
cuser, chost, pkalg, slen);
#ifdef DEBUG_PK
debug("signature:");
sshbuf_dump_data(sig, siglen, stderr);
#endif
pktype = sshkey_type_from_name(pkalg);
if (pktype == KEY_UNSPEC) {
/* this is perfectly legal */
logit("%s: unsupported public key algorithm: %s",
__func__, pkalg);
goto done;
}
if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
error("%s: key_from_blob: %s", __func__, ssh_err(r));
goto done;
}
if (key == NULL) {
error("%s: cannot decode key: %s", __func__, pkalg);
goto done;
}
if (key->type != pktype) {
error("%s: type mismatch for decoded key "
"(received %d, expected %d)", __func__, key->type, pktype);
goto done;
}
if (sshkey_type_plain(key->type) == KEY_RSA &&
(ssh->compat & SSH_BUG_RSASIGMD5) != 0) {
error("Refusing RSA key because peer uses unsafe "
"signature format");
goto done;
}
if (match_pattern_list(sshkey_ssh_name(key),
options.hostbased_key_types, 0) != 1) {
logit("%s: key type %s not in HostbasedAcceptedKeyTypes",
__func__, sshkey_type(key));
goto done;
}
if ((b = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
/* reconstruct packet */
if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
(r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
(r = sshbuf_put_cstring(b, authctxt->user)) != 0 ||
(r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
(r = sshbuf_put_cstring(b, "hostbased")) != 0 ||
(r = sshbuf_put_string(b, pkalg, alen)) != 0 ||
(r = sshbuf_put_string(b, pkblob, blen)) != 0 ||
(r = sshbuf_put_cstring(b, chost)) != 0 ||
(r = sshbuf_put_cstring(b, cuser)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
#ifdef DEBUG_PK
sshbuf_dump(b, stderr);
#endif
auth2_record_info(authctxt,
"client user \"%.100s\", client host \"%.100s\"", cuser, chost);
/* test for allowed key and correct signature */
authenticated = 0;
if (PRIVSEP(hostbased_key_allowed(authctxt->pw, cuser, chost, key)) &&
PRIVSEP(sshkey_verify(key, sig, slen,
sshbuf_ptr(b), sshbuf_len(b), pkalg, ssh->compat)) == 0)
authenticated = 1;
auth2_record_key(authctxt, authenticated, key);
sshbuf_free(b);
done:
debug2("%s: authenticated %d", __func__, authenticated);
sshkey_free(key);
free(pkalg);
free(pkblob);
free(cuser);
free(chost);
free(sig);
return authenticated;
}
void
tests(void)
{
TEST_START("match_pattern");
ASSERT_INT_EQ(match_pattern("", ""), 1);
ASSERT_INT_EQ(match_pattern("", "aaa"), 0);
ASSERT_INT_EQ(match_pattern("aaa", ""), 0);
ASSERT_INT_EQ(match_pattern("aaa", "aaaa"), 0);
ASSERT_INT_EQ(match_pattern("aaaa", "aaa"), 0);
TEST_DONE();
TEST_START("match_pattern wildcard");
ASSERT_INT_EQ(match_pattern("", "*"), 1);
ASSERT_INT_EQ(match_pattern("a", "?"), 1);
ASSERT_INT_EQ(match_pattern("aa", "a?"), 1);
ASSERT_INT_EQ(match_pattern("a", "*"), 1);
ASSERT_INT_EQ(match_pattern("aa", "a*"), 1);
ASSERT_INT_EQ(match_pattern("aa", "?*"), 1);
ASSERT_INT_EQ(match_pattern("aa", "**"), 1);
ASSERT_INT_EQ(match_pattern("aa", "?a"), 1);
ASSERT_INT_EQ(match_pattern("aa", "*a"), 1);
ASSERT_INT_EQ(match_pattern("ba", "a?"), 0);
ASSERT_INT_EQ(match_pattern("ba", "a*"), 0);
ASSERT_INT_EQ(match_pattern("ab", "?a"), 0);
ASSERT_INT_EQ(match_pattern("ab", "*a"), 0);
TEST_DONE();
TEST_START("match_pattern_list");
ASSERT_INT_EQ(match_pattern_list("", "", 0), 0); /* no patterns */
ASSERT_INT_EQ(match_pattern_list("", "*", 0), 1);
ASSERT_INT_EQ(match_pattern_list("", "!*", 0), -1);
ASSERT_INT_EQ(match_pattern_list("", "!a,*", 0), 1);
ASSERT_INT_EQ(match_pattern_list("", "*,!a", 0), 1);
ASSERT_INT_EQ(match_pattern_list("", "a,!*", 0), -1);
ASSERT_INT_EQ(match_pattern_list("", "!*,a", 0), -1);
ASSERT_INT_EQ(match_pattern_list("a", "", 0), 0);
ASSERT_INT_EQ(match_pattern_list("a", "*", 0), 1);
ASSERT_INT_EQ(match_pattern_list("a", "!*", 0), -1);
ASSERT_INT_EQ(match_pattern_list("a", "!a", 0), -1);
/* XXX negated ASSERT_INT_EQ(match_pattern_list("a", "!b", 0), 1); */
ASSERT_INT_EQ(match_pattern_list("a", "!a,*", 0), -1);
ASSERT_INT_EQ(match_pattern_list("b", "!a,*", 0), 1);
ASSERT_INT_EQ(match_pattern_list("a", "*,!a", 0), -1);
ASSERT_INT_EQ(match_pattern_list("b", "*,!a", 0), 1);
ASSERT_INT_EQ(match_pattern_list("a", "a,!*", 0), -1);
ASSERT_INT_EQ(match_pattern_list("b", "a,!*", 0), -1);
ASSERT_INT_EQ(match_pattern_list("a", "a,!a", 0), -1);
/* XXX negated ASSERT_INT_EQ(match_pattern_list("b", "a,!a", 0), 1); */
ASSERT_INT_EQ(match_pattern_list("a", "!*,a", 0), -1);
ASSERT_INT_EQ(match_pattern_list("b", "!*,a", 0), -1);
TEST_DONE();
TEST_START("match_pattern_list lowercase");
ASSERT_INT_EQ(match_pattern_list("abc", "ABC", 0), 0);
ASSERT_INT_EQ(match_pattern_list("ABC", "abc", 0), 0);
ASSERT_INT_EQ(match_pattern_list("abc", "ABC", 1), 1);
ASSERT_INT_EQ(match_pattern_list("ABC", "abc", 1), 0);
TEST_DONE();
TEST_START("addr_match_list");
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "127.0.0.1/44"), -2);
ASSERT_INT_EQ(addr_match_list(NULL, "127.0.0.1/44"), -2);
ASSERT_INT_EQ(addr_match_list("a", "*"), 0);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "*"), 1);
ASSERT_INT_EQ(addr_match_list(NULL, "*"), 0);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "127.0.0.1"), 1);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "127.0.0.2"), 0);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "!127.0.0.1"), -1);
/* XXX negated ASSERT_INT_EQ(addr_match_list("127.0.0.1", "!127.0.0.2"), 1); */
ASSERT_INT_EQ(addr_match_list("127.0.0.255", "127.0.0.0/24"), 1);
ASSERT_INT_EQ(addr_match_list("127.0.1.1", "127.0.0.0/24"), 0);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "127.0.0.0/24"), 1);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "127.0.1.0/24"), 0);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "!127.0.0.0/24"), -1);
/* XXX negated ASSERT_INT_EQ(addr_match_list("127.0.0.1", "!127.0.1.0/24"), 1); */
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "10.0.0.1,!127.0.0.1"), -1);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "!127.0.0.1,10.0.0.1"), -1);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "10.0.0.1,127.0.0.2"), 0);
ASSERT_INT_EQ(addr_match_list("127.0.0.1", "127.0.0.2,10.0.0.1"), 0);
/* XXX negated ASSERT_INT_EQ(addr_match_list("127.0.0.1", "10.0.0.1,!127.0.0.2"), 1); */
/* XXX negated ASSERT_INT_EQ(addr_match_list("127.0.0.1", "!127.0.0.2,10.0.0.1"), 1); */
TEST_DONE();
#define CHECK_FILTER(string,filter,expected) \
do { \
char *result = match_filter_list((string), (filter)); \
ASSERT_STRING_EQ(result, expected); \
free(result); \
} while (0)
TEST_START("match_filter_list");
CHECK_FILTER("a,b,c", "", "a,b,c");
CHECK_FILTER("a,b,c", "a", "b,c");
CHECK_FILTER("a,b,c", "b", "a,c");
CHECK_FILTER("a,b,c", "c", "a,b");
CHECK_FILTER("a,b,c", "a,b", "c");
CHECK_FILTER("a,b,c", "a,c", "b");
CHECK_FILTER("a,b,c", "b,c", "a");
CHECK_FILTER("a,b,c", "a,b,c", "");
CHECK_FILTER("a,b,c", "b,c", "a");
CHECK_FILTER("", "a,b,c", "");
TEST_DONE();
/*
* XXX TODO
* int match_host_and_ip(const char *, const char *, const char *);
* int match_user(const char *, const char *, const char *, const char *);
* char *match_list(const char *, const char *, u_int *);
* int addr_match_cidr_list(const char *, const char *);
*/
}
static int
userauth_pubkey(Authctxt *authctxt)
{
Buffer b;
Key *key = NULL;
char *pkalg, *userstyle;
u_char *pkblob, *sig;
u_int alen, blen, slen;
int have_sig, pktype;
int authenticated = 0;
if (!authctxt->valid) {
debug2("userauth_pubkey: disabled because of invalid user");
return 0;
}
have_sig = packet_get_char();
if (datafellows & SSH_BUG_PKAUTH) {
debug2("userauth_pubkey: SSH_BUG_PKAUTH");
/* no explicit pkalg given */
pkblob = packet_get_string(&blen);
buffer_init(&b);
buffer_append(&b, pkblob, blen);
/* so we have to extract the pkalg from the pkblob */
pkalg = buffer_get_string(&b, &alen);
buffer_free(&b);
} else {
pkalg = packet_get_string(&alen);
pkblob = packet_get_string(&blen);
}
pktype = key_type_from_name(pkalg);
if (pktype == KEY_UNSPEC) {
/* this is perfectly legal */
logit("userauth_pubkey: unsupported public key algorithm: %s",
pkalg);
goto done;
}
key = key_from_blob(pkblob, blen);
if (key == NULL) {
error("userauth_pubkey: cannot decode key: %s", pkalg);
goto done;
}
if (key->type != pktype) {
error("userauth_pubkey: type mismatch for decoded key "
"(received %d, expected %d)", key->type, pktype);
goto done;
}
if (key_type_plain(key->type) == KEY_RSA &&
(datafellows & SSH_BUG_RSASIGMD5) != 0) {
logit("Refusing RSA key because client uses unsafe "
"signature scheme");
goto done;
}
if (auth2_userkey_already_used(authctxt, key)) {
logit("refusing previously-used %s key", key_type(key));
goto done;
}
if (match_pattern_list(sshkey_ssh_name(key), options.pubkey_key_types,
strlen(options.pubkey_key_types), 0) != 1) {
logit("%s: key type %s not in PubkeyAcceptedKeyTypes",
__func__, sshkey_ssh_name(key));
goto done;
}
if (have_sig) {
sig = packet_get_string(&slen);
packet_check_eom();
buffer_init(&b);
if (datafellows & SSH_OLD_SESSIONID) {
buffer_append(&b, session_id2, session_id2_len);
} else {
buffer_put_string(&b, session_id2, session_id2_len);
}
/* reconstruct packet */
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
buffer_put_cstring(&b, userstyle);
free(userstyle);
buffer_put_cstring(&b,
datafellows & SSH_BUG_PKSERVICE ?
"ssh-userauth" :
authctxt->service);
if (datafellows & SSH_BUG_PKAUTH) {
buffer_put_char(&b, have_sig);
} else {
buffer_put_cstring(&b, "publickey");
buffer_put_char(&b, have_sig);
buffer_put_cstring(&b, pkalg);
}
buffer_put_string(&b, pkblob, blen);
#ifdef DEBUG_PK
buffer_dump(&b);
#endif
pubkey_auth_info(authctxt, key, NULL);
/* test for correct signature */
authenticated = 0;
if (PRIVSEP(user_key_allowed(authctxt->pw, key)) &&
PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
buffer_len(&b))) == 1) {
authenticated = 1;
/* Record the successful key to prevent reuse */
auth2_record_userkey(authctxt, key);
key = NULL; /* Don't free below */
}
buffer_free(&b);
free(sig);
} else {
debug("test whether pkalg/pkblob are acceptable");
packet_check_eom();
/* XXX fake reply and always send PK_OK ? */
/*
* XXX this allows testing whether a user is allowed
* to login: if you happen to have a valid pubkey this
* message is sent. the message is NEVER sent at all
* if a user is not allowed to login. is this an
* issue? -markus
*/
if (PRIVSEP(user_key_allowed(authctxt->pw, key))) {
packet_start(SSH2_MSG_USERAUTH_PK_OK);
packet_put_string(pkalg, alen);
packet_put_string(pkblob, blen);
packet_send();
packet_write_wait();
authctxt->postponed = 1;
}
}
if (authenticated != 1)
auth_clear_options();
done:
debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
if (key != NULL)
key_free(key);
free(pkalg);
free(pkblob);
return authenticated;
}
/* datafellows bug compatibility */
u_int
compat_datafellows(const char *version)
{
int i;
static struct {
char *pat;
int bugs;
} check[] = {
{ "OpenSSH_2.*,"
"OpenSSH_3.0*,"
"OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_OLD_FORWARD_ADDR|
SSH_BUG_SIGTYPE},
{ "OpenSSH_3.*", SSH_OLD_FORWARD_ADDR|SSH_BUG_SIGTYPE },
{ "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF|
SSH_BUG_SIGTYPE},
{ "OpenSSH_2*,"
"OpenSSH_3*,"
"OpenSSH_4*", SSH_BUG_SIGTYPE },
{ "OpenSSH_5*", SSH_NEW_OPENSSH|SSH_BUG_DYNAMIC_RPORT|
SSH_BUG_SIGTYPE},
{ "OpenSSH_6.6.1*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE},
{ "OpenSSH_6.5*,"
"OpenSSH_6.6*", SSH_NEW_OPENSSH|SSH_BUG_CURVE25519PAD|
SSH_BUG_SIGTYPE},
{ "OpenSSH_7.0*,"
"OpenSSH_7.1*,"
"OpenSSH_7.2*,"
"OpenSSH_7.3*,"
"OpenSSH_7.4*,"
"OpenSSH_7.5*,"
"OpenSSH_7.6*,"
"OpenSSH_7.7*", SSH_NEW_OPENSSH|SSH_BUG_SIGTYPE},
{ "OpenSSH*", SSH_NEW_OPENSSH },
{ "*MindTerm*", 0 },
{ "3.0.*", SSH_BUG_DEBUG },
{ "3.0 SecureCRT*", SSH_OLD_SESSIONID },
{ "1.7 SecureFX*", SSH_OLD_SESSIONID },
{ "1.2.18*,"
"1.2.19*,"
"1.2.20*,"
"1.2.21*,"
"1.2.22*", SSH_BUG_IGNOREMSG },
{ "1.3.2*", /* F-Secure */
SSH_BUG_IGNOREMSG },
{ "Cisco-1.*", SSH_BUG_DHGEX_LARGE|
SSH_BUG_HOSTKEYS },
{ "*SSH Compatible Server*", /* Netscreen */
SSH_BUG_PASSWORDPAD },
{ "*OSU_0*,"
"OSU_1.0*,"
"OSU_1.1*,"
"OSU_1.2*,"
"OSU_1.3*,"
"OSU_1.4*,"
"OSU_1.5alpha1*,"
"OSU_1.5alpha2*,"
"OSU_1.5alpha3*", SSH_BUG_PASSWORDPAD },
{ "*SSH_Version_Mapper*",
SSH_BUG_SCANNER },
{ "PuTTY_Local:*," /* dev versions < Sep 2014 */
"PuTTY-Release-0.5*," /* 0.50-0.57, DH-GEX in >=0.52 */
"PuTTY_Release_0.5*," /* 0.58-0.59 */
"PuTTY_Release_0.60*,"
"PuTTY_Release_0.61*,"
"PuTTY_Release_0.62*,"
"PuTTY_Release_0.63*,"
"PuTTY_Release_0.64*",
SSH_OLD_DHGEX },
{ "FuTTY*", SSH_OLD_DHGEX }, /* Putty Fork */
{ "Probe-*",
SSH_BUG_PROBE },
{ "TeraTerm SSH*,"
"TTSSH/1.5.*,"
"TTSSH/2.1*,"
"TTSSH/2.2*,"
"TTSSH/2.3*,"
"TTSSH/2.4*,"
"TTSSH/2.5*,"
"TTSSH/2.6*,"
"TTSSH/2.70*,"
"TTSSH/2.71*,"
"TTSSH/2.72*", SSH_BUG_HOSTKEYS },
{ "WinSCP_release_4*,"
"WinSCP_release_5.0*,"
"WinSCP_release_5.1,"
"WinSCP_release_5.1.*,"
"WinSCP_release_5.5,"
"WinSCP_release_5.5.*,"
"WinSCP_release_5.6,"
"WinSCP_release_5.6.*,"
"WinSCP_release_5.7,"
"WinSCP_release_5.7.1,"
"WinSCP_release_5.7.2,"
"WinSCP_release_5.7.3,"
"WinSCP_release_5.7.4",
SSH_OLD_DHGEX },
{ "ConfD-*",
SSH_BUG_UTF8TTYMODE },
{ "Twisted_*", 0 },
{ "Twisted*", SSH_BUG_DEBUG },
{ NULL, 0 }
};
/* process table, return first match */
for (i = 0; check[i].pat; i++) {
if (match_pattern_list(version, check[i].pat, 0) == 1) {
debug("match: %s pat %s compat 0x%08x",
version, check[i].pat, check[i].bugs);
datafellows = check[i].bugs; /* XXX for now */
return check[i].bugs;
}
}
debug("no match: %s", version);
return 0;
}
/*
* Tries to match the host name (which must be in all lowercase) against the
* comma-separated sequence of subpatterns (each possibly preceded by ! to
* indicate negation).
* Returns -1 if negation matches, 1 if there is a positive match, 0 if there
* is no match at all.
*/
int match_hostname(const char *host, const char *pattern, unsigned int len) {
return match_pattern_list(host, pattern, len, 1);
}
int
mm_answer_keyallowed(int sock, Buffer *m)
{
struct sshkey *key;
char *cuser, *chost;
u_char *blob;
u_int bloblen, pubkey_auth_attempt;
enum mm_keytype type = 0;
int allowed = 0;
debug3("%s entering", __func__);
type = buffer_get_int(m);
cuser = buffer_get_string(m, NULL);
chost = buffer_get_string(m, NULL);
blob = buffer_get_string(m, &bloblen);
pubkey_auth_attempt = buffer_get_int(m);
key = key_from_blob(blob, bloblen);
debug3("%s: key_from_blob: %p", __func__, key);
if (key != NULL && authctxt->valid) {
/* These should not make it past the privsep child */
if (key_type_plain(key->type) == KEY_RSA &&
(datafellows & SSH_BUG_RSASIGMD5) != 0)
fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
switch (type) {
case MM_USERKEY:
allowed = options.pubkey_authentication &&
!auth2_key_already_used(authctxt, key) &&
match_pattern_list(sshkey_ssh_name(key),
options.pubkey_key_types, 0) == 1 &&
user_key_allowed(authctxt->pw, key,
pubkey_auth_attempt);
auth_method = "publickey";
if (options.pubkey_authentication &&
(!pubkey_auth_attempt || allowed != 1))
auth_clear_options();
break;
case MM_HOSTKEY:
allowed = options.hostbased_authentication &&
!auth2_key_already_used(authctxt, key) &&
match_pattern_list(sshkey_ssh_name(key),
options.hostbased_key_types, 0) == 1 &&
hostbased_key_allowed(authctxt->pw,
cuser, chost, key);
auth2_record_info(authctxt,
"client user \"%.100s\", client host \"%.100s\"",
cuser, chost);
auth_method = "hostbased";
break;
default:
fatal("%s: unknown key type %d", __func__, type);
break;
}
}
debug3("%s: key is %s", __func__, allowed ? "allowed" : "not allowed");
auth2_record_key(authctxt, 0, key);
sshkey_free(key);
/* clear temporarily storage (used by verify) */
monitor_reset_key_state();
if (allowed) {
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = bloblen;
key_blobtype = type;
hostbased_cuser = cuser;
hostbased_chost = chost;
} else {
/* Log failed attempt */
auth_log(authctxt, 0, 0, auth_method, NULL);
free(blob);
free(cuser);
free(chost);
}
buffer_clear(m);
buffer_put_int(m, allowed);
buffer_put_int(m, forced_command != NULL);
mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
return (0);
}
