version 1.52.2.1, 2003/09/16 21:20:28 |
version 1.53, 2003/04/08 20:21:29 |
|
|
#include <openssl/bn.h> |
#include <openssl/bn.h> |
#include <openssl/md5.h> |
#include <openssl/md5.h> |
|
|
|
#ifdef KRB4 |
|
#include <krb.h> |
|
#endif |
|
#ifdef KRB5 |
|
#include <krb5.h> |
|
#endif |
|
#ifdef AFS |
|
#include <kafs.h> |
|
#include "radix.h" |
|
#endif |
|
|
#include "ssh.h" |
#include "ssh.h" |
#include "ssh1.h" |
#include "ssh1.h" |
#include "xmalloc.h" |
#include "xmalloc.h" |
|
|
return 0; |
return 0; |
} |
} |
|
|
|
#ifdef KRB4 |
|
static int |
|
try_krb4_authentication(void) |
|
{ |
|
KTEXT_ST auth; /* Kerberos data */ |
|
char *reply; |
|
char inst[INST_SZ]; |
|
char *realm; |
|
CREDENTIALS cred; |
|
int r, type; |
|
socklen_t slen; |
|
Key_schedule schedule; |
|
u_long checksum, cksum; |
|
MSG_DAT msg_data; |
|
struct sockaddr_in local, foreign; |
|
struct stat st; |
|
|
|
/* Don't do anything if we don't have any tickets. */ |
|
if (stat(tkt_string(), &st) < 0) |
|
return 0; |
|
|
|
strlcpy(inst, (char *)krb_get_phost(get_canonical_hostname(1)), |
|
INST_SZ); |
|
|
|
realm = (char *)krb_realmofhost(get_canonical_hostname(1)); |
|
if (!realm) { |
|
debug("Kerberos v4: no realm for %s", get_canonical_hostname(1)); |
|
return 0; |
|
} |
|
/* This can really be anything. */ |
|
checksum = (u_long)getpid(); |
|
|
|
r = krb_mk_req(&auth, KRB4_SERVICE_NAME, inst, realm, checksum); |
|
if (r != KSUCCESS) { |
|
debug("Kerberos v4 krb_mk_req failed: %s", krb_err_txt[r]); |
|
return 0; |
|
} |
|
/* Get session key to decrypt the server's reply with. */ |
|
r = krb_get_cred(KRB4_SERVICE_NAME, inst, realm, &cred); |
|
if (r != KSUCCESS) { |
|
debug("get_cred failed: %s", krb_err_txt[r]); |
|
return 0; |
|
} |
|
des_key_sched((des_cblock *) cred.session, schedule); |
|
|
|
/* Send authentication info to server. */ |
|
packet_start(SSH_CMSG_AUTH_KERBEROS); |
|
packet_put_string((char *) auth.dat, auth.length); |
|
packet_send(); |
|
packet_write_wait(); |
|
|
|
/* Zero the buffer. */ |
|
(void) memset(auth.dat, 0, MAX_KTXT_LEN); |
|
|
|
slen = sizeof(local); |
|
memset(&local, 0, sizeof(local)); |
|
if (getsockname(packet_get_connection_in(), |
|
(struct sockaddr *)&local, &slen) < 0) |
|
debug("getsockname failed: %s", strerror(errno)); |
|
|
|
slen = sizeof(foreign); |
|
memset(&foreign, 0, sizeof(foreign)); |
|
if (getpeername(packet_get_connection_in(), |
|
(struct sockaddr *)&foreign, &slen) < 0) { |
|
debug("getpeername failed: %s", strerror(errno)); |
|
fatal_cleanup(); |
|
} |
|
/* Get server reply. */ |
|
type = packet_read(); |
|
switch (type) { |
|
case SSH_SMSG_FAILURE: |
|
/* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */ |
|
debug("Kerberos v4 authentication failed."); |
|
return 0; |
|
break; |
|
|
|
case SSH_SMSG_AUTH_KERBEROS_RESPONSE: |
|
/* SSH_SMSG_AUTH_KERBEROS_SUCCESS */ |
|
debug("Kerberos v4 authentication accepted."); |
|
|
|
/* Get server's response. */ |
|
reply = packet_get_string((u_int *) &auth.length); |
|
if (auth.length >= MAX_KTXT_LEN) |
|
fatal("Kerberos v4: Malformed response from server"); |
|
memcpy(auth.dat, reply, auth.length); |
|
xfree(reply); |
|
|
|
packet_check_eom(); |
|
|
|
/* |
|
* If his response isn't properly encrypted with the session |
|
* key, and the decrypted checksum fails to match, he's |
|
* bogus. Bail out. |
|
*/ |
|
r = krb_rd_priv(auth.dat, auth.length, schedule, &cred.session, |
|
&foreign, &local, &msg_data); |
|
if (r != KSUCCESS) { |
|
debug("Kerberos v4 krb_rd_priv failed: %s", |
|
krb_err_txt[r]); |
|
packet_disconnect("Kerberos v4 challenge failed!"); |
|
} |
|
/* Fetch the (incremented) checksum that we supplied in the request. */ |
|
memcpy((char *)&cksum, (char *)msg_data.app_data, |
|
sizeof(cksum)); |
|
cksum = ntohl(cksum); |
|
|
|
/* If it matches, we're golden. */ |
|
if (cksum == checksum + 1) { |
|
debug("Kerberos v4 challenge successful."); |
|
return 1; |
|
} else |
|
packet_disconnect("Kerberos v4 challenge failed!"); |
|
break; |
|
|
|
default: |
|
packet_disconnect("Protocol error on Kerberos v4 response: %d", type); |
|
} |
|
return 0; |
|
} |
|
|
|
#endif /* KRB4 */ |
|
|
|
#ifdef KRB5 |
|
static int |
|
try_krb5_authentication(krb5_context *context, krb5_auth_context *auth_context) |
|
{ |
|
krb5_error_code problem; |
|
const char *tkfile; |
|
struct stat buf; |
|
krb5_ccache ccache = NULL; |
|
const char *remotehost; |
|
krb5_data ap; |
|
int type; |
|
krb5_ap_rep_enc_part *reply = NULL; |
|
int ret; |
|
|
|
memset(&ap, 0, sizeof(ap)); |
|
|
|
problem = krb5_init_context(context); |
|
if (problem) { |
|
debug("Kerberos v5: krb5_init_context failed"); |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
tkfile = krb5_cc_default_name(*context); |
|
if (strncmp(tkfile, "FILE:", 5) == 0) |
|
tkfile += 5; |
|
|
|
if (stat(tkfile, &buf) == 0 && getuid() != buf.st_uid) { |
|
debug("Kerberos v5: could not get default ccache (permission denied)."); |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
problem = krb5_cc_default(*context, &ccache); |
|
if (problem) { |
|
debug("Kerberos v5: krb5_cc_default failed: %s", |
|
krb5_get_err_text(*context, problem)); |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
remotehost = get_canonical_hostname(1); |
|
|
|
problem = krb5_mk_req(*context, auth_context, AP_OPTS_MUTUAL_REQUIRED, |
|
"host", remotehost, NULL, ccache, &ap); |
|
if (problem) { |
|
debug("Kerberos v5: krb5_mk_req failed: %s", |
|
krb5_get_err_text(*context, problem)); |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
packet_start(SSH_CMSG_AUTH_KERBEROS); |
|
packet_put_string((char *) ap.data, ap.length); |
|
packet_send(); |
|
packet_write_wait(); |
|
|
|
xfree(ap.data); |
|
ap.length = 0; |
|
|
|
type = packet_read(); |
|
switch (type) { |
|
case SSH_SMSG_FAILURE: |
|
/* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */ |
|
debug("Kerberos v5 authentication failed."); |
|
ret = 0; |
|
break; |
|
|
|
case SSH_SMSG_AUTH_KERBEROS_RESPONSE: |
|
/* SSH_SMSG_AUTH_KERBEROS_SUCCESS */ |
|
debug("Kerberos v5 authentication accepted."); |
|
|
|
/* Get server's response. */ |
|
ap.data = packet_get_string((unsigned int *) &ap.length); |
|
packet_check_eom(); |
|
/* XXX je to dobre? */ |
|
|
|
problem = krb5_rd_rep(*context, *auth_context, &ap, &reply); |
|
if (problem) { |
|
ret = 0; |
|
} |
|
ret = 1; |
|
break; |
|
|
|
default: |
|
packet_disconnect("Protocol error on Kerberos v5 response: %d", |
|
type); |
|
ret = 0; |
|
break; |
|
|
|
} |
|
|
|
out: |
|
if (ccache != NULL) |
|
krb5_cc_close(*context, ccache); |
|
if (reply != NULL) |
|
krb5_free_ap_rep_enc_part(*context, reply); |
|
if (ap.length > 0) |
|
krb5_data_free(&ap); |
|
|
|
return (ret); |
|
} |
|
|
|
static void |
|
send_krb5_tgt(krb5_context context, krb5_auth_context auth_context) |
|
{ |
|
int fd, type; |
|
krb5_error_code problem; |
|
krb5_data outbuf; |
|
krb5_ccache ccache = NULL; |
|
krb5_creds creds; |
|
krb5_kdc_flags flags; |
|
const char *remotehost; |
|
|
|
memset(&creds, 0, sizeof(creds)); |
|
memset(&outbuf, 0, sizeof(outbuf)); |
|
|
|
fd = packet_get_connection_in(); |
|
|
|
problem = krb5_auth_con_setaddrs_from_fd(context, auth_context, &fd); |
|
if (problem) |
|
goto out; |
|
|
|
problem = krb5_cc_default(context, &ccache); |
|
if (problem) |
|
goto out; |
|
|
|
problem = krb5_cc_get_principal(context, ccache, &creds.client); |
|
if (problem) |
|
goto out; |
|
|
|
problem = krb5_build_principal(context, &creds.server, |
|
strlen(creds.client->realm), creds.client->realm, |
|
"krbtgt", creds.client->realm, NULL); |
|
if (problem) |
|
goto out; |
|
|
|
creds.times.endtime = 0; |
|
|
|
flags.i = 0; |
|
flags.b.forwarded = 1; |
|
flags.b.forwardable = krb5_config_get_bool(context, NULL, |
|
"libdefaults", "forwardable", NULL); |
|
|
|
remotehost = get_canonical_hostname(1); |
|
|
|
problem = krb5_get_forwarded_creds(context, auth_context, |
|
ccache, flags.i, remotehost, &creds, &outbuf); |
|
if (problem) |
|
goto out; |
|
|
|
packet_start(SSH_CMSG_HAVE_KERBEROS_TGT); |
|
packet_put_string((char *)outbuf.data, outbuf.length); |
|
packet_send(); |
|
packet_write_wait(); |
|
|
|
type = packet_read(); |
|
|
|
if (type == SSH_SMSG_SUCCESS) { |
|
char *pname; |
|
|
|
krb5_unparse_name(context, creds.client, &pname); |
|
debug("Kerberos v5 TGT forwarded (%s).", pname); |
|
xfree(pname); |
|
} else |
|
debug("Kerberos v5 TGT forwarding failed."); |
|
|
|
return; |
|
|
|
out: |
|
if (problem) |
|
debug("Kerberos v5 TGT forwarding failed: %s", |
|
krb5_get_err_text(context, problem)); |
|
if (creds.client) |
|
krb5_free_principal(context, creds.client); |
|
if (creds.server) |
|
krb5_free_principal(context, creds.server); |
|
if (ccache) |
|
krb5_cc_close(context, ccache); |
|
if (outbuf.data) |
|
xfree(outbuf.data); |
|
} |
|
#endif /* KRB5 */ |
|
|
|
#ifdef AFS |
|
static void |
|
send_krb4_tgt(void) |
|
{ |
|
CREDENTIALS *creds; |
|
struct stat st; |
|
char buffer[4096], pname[ANAME_SZ], pinst[INST_SZ], prealm[REALM_SZ]; |
|
int problem, type; |
|
|
|
/* Don't do anything if we don't have any tickets. */ |
|
if (stat(tkt_string(), &st) < 0) |
|
return; |
|
|
|
creds = xmalloc(sizeof(*creds)); |
|
|
|
problem = krb_get_tf_fullname(TKT_FILE, pname, pinst, prealm); |
|
if (problem) |
|
goto out; |
|
|
|
problem = krb_get_cred("krbtgt", prealm, prealm, creds); |
|
if (problem) |
|
goto out; |
|
|
|
if (time(0) > krb_life_to_time(creds->issue_date, creds->lifetime)) { |
|
problem = RD_AP_EXP; |
|
goto out; |
|
} |
|
creds_to_radix(creds, (u_char *)buffer, sizeof(buffer)); |
|
|
|
packet_start(SSH_CMSG_HAVE_KERBEROS_TGT); |
|
packet_put_cstring(buffer); |
|
packet_send(); |
|
packet_write_wait(); |
|
|
|
type = packet_read(); |
|
|
|
if (type == SSH_SMSG_SUCCESS) |
|
debug("Kerberos v4 TGT forwarded (%s%s%s@%s).", |
|
creds->pname, creds->pinst[0] ? "." : "", |
|
creds->pinst, creds->realm); |
|
else |
|
debug("Kerberos v4 TGT rejected."); |
|
|
|
xfree(creds); |
|
return; |
|
|
|
out: |
|
debug("Kerberos v4 TGT passing failed: %s", krb_err_txt[problem]); |
|
xfree(creds); |
|
} |
|
|
|
static void |
|
send_afs_tokens(void) |
|
{ |
|
CREDENTIALS creds; |
|
struct ViceIoctl parms; |
|
struct ClearToken ct; |
|
int i, type, len; |
|
char buf[2048], *p, *server_cell; |
|
char buffer[8192]; |
|
|
|
/* Move over ktc_GetToken, here's something leaner. */ |
|
for (i = 0; i < 100; i++) { /* just in case */ |
|
parms.in = (char *) &i; |
|
parms.in_size = sizeof(i); |
|
parms.out = buf; |
|
parms.out_size = sizeof(buf); |
|
if (k_pioctl(0, VIOCGETTOK, &parms, 0) != 0) |
|
break; |
|
p = buf; |
|
|
|
/* Get secret token. */ |
|
memcpy(&creds.ticket_st.length, p, sizeof(u_int)); |
|
if (creds.ticket_st.length > MAX_KTXT_LEN) |
|
break; |
|
p += sizeof(u_int); |
|
memcpy(creds.ticket_st.dat, p, creds.ticket_st.length); |
|
p += creds.ticket_st.length; |
|
|
|
/* Get clear token. */ |
|
memcpy(&len, p, sizeof(len)); |
|
if (len != sizeof(struct ClearToken)) |
|
break; |
|
p += sizeof(len); |
|
memcpy(&ct, p, len); |
|
p += len; |
|
p += sizeof(len); /* primary flag */ |
|
server_cell = p; |
|
|
|
/* Flesh out our credentials. */ |
|
strlcpy(creds.service, "afs", sizeof(creds.service)); |
|
creds.instance[0] = '\0'; |
|
strlcpy(creds.realm, server_cell, REALM_SZ); |
|
memcpy(creds.session, ct.HandShakeKey, DES_KEY_SZ); |
|
creds.issue_date = ct.BeginTimestamp; |
|
creds.lifetime = krb_time_to_life(creds.issue_date, |
|
ct.EndTimestamp); |
|
creds.kvno = ct.AuthHandle; |
|
snprintf(creds.pname, sizeof(creds.pname), "AFS ID %d", ct.ViceId); |
|
creds.pinst[0] = '\0'; |
|
|
|
/* Encode token, ship it off. */ |
|
if (creds_to_radix(&creds, (u_char *)buffer, |
|
sizeof(buffer)) <= 0) |
|
break; |
|
packet_start(SSH_CMSG_HAVE_AFS_TOKEN); |
|
packet_put_cstring(buffer); |
|
packet_send(); |
|
packet_write_wait(); |
|
|
|
/* Roger, Roger. Clearance, Clarence. What's your vector, |
|
Victor? */ |
|
type = packet_read(); |
|
|
|
if (type == SSH_SMSG_FAILURE) |
|
debug("AFS token for cell %s rejected.", server_cell); |
|
else if (type != SSH_SMSG_SUCCESS) |
|
packet_disconnect("Protocol error on AFS token response: %d", type); |
|
} |
|
} |
|
|
|
#endif /* AFS */ |
|
|
/* |
/* |
* Tries to authenticate with any string-based challenge/response system. |
* Tries to authenticate with any string-based challenge/response system. |
* Note that the client code is not tied to s/key or TIS. |
* Note that the client code is not tied to s/key or TIS. |
|
|
ssh_userauth1(const char *local_user, const char *server_user, char *host, |
ssh_userauth1(const char *local_user, const char *server_user, char *host, |
Sensitive *sensitive) |
Sensitive *sensitive) |
{ |
{ |
|
#ifdef KRB5 |
|
krb5_context context = NULL; |
|
krb5_auth_context auth_context = NULL; |
|
#endif |
int i, type; |
int i, type; |
|
|
if (supported_authentications == 0) |
if (supported_authentications == 0) |
|
|
if (type != SSH_SMSG_FAILURE) |
if (type != SSH_SMSG_FAILURE) |
packet_disconnect("Protocol error: got %d in response to SSH_CMSG_USER", type); |
packet_disconnect("Protocol error: got %d in response to SSH_CMSG_USER", type); |
|
|
|
#ifdef KRB5 |
|
if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) && |
|
options.kerberos_authentication) { |
|
debug("Trying Kerberos v5 authentication."); |
|
|
|
if (try_krb5_authentication(&context, &auth_context)) { |
|
type = packet_read(); |
|
if (type == SSH_SMSG_SUCCESS) |
|
goto success; |
|
if (type != SSH_SMSG_FAILURE) |
|
packet_disconnect("Protocol error: got %d in response to Kerberos v5 auth", type); |
|
} |
|
} |
|
#endif /* KRB5 */ |
|
|
|
#ifdef KRB4 |
|
if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) && |
|
options.kerberos_authentication) { |
|
debug("Trying Kerberos v4 authentication."); |
|
|
|
if (try_krb4_authentication()) { |
|
type = packet_read(); |
|
if (type == SSH_SMSG_SUCCESS) |
|
goto success; |
|
if (type != SSH_SMSG_FAILURE) |
|
packet_disconnect("Protocol error: got %d in response to Kerberos v4 auth", type); |
|
} |
|
} |
|
#endif /* KRB4 */ |
|
|
/* |
/* |
|
* Use rhosts authentication if running in privileged socket and we |
|
* do not wish to remain anonymous. |
|
*/ |
|
if ((supported_authentications & (1 << SSH_AUTH_RHOSTS)) && |
|
options.rhosts_authentication) { |
|
debug("Trying rhosts authentication."); |
|
packet_start(SSH_CMSG_AUTH_RHOSTS); |
|
packet_put_cstring(local_user); |
|
packet_send(); |
|
packet_write_wait(); |
|
|
|
/* The server should respond with success or failure. */ |
|
type = packet_read(); |
|
if (type == SSH_SMSG_SUCCESS) |
|
goto success; |
|
if (type != SSH_SMSG_FAILURE) |
|
packet_disconnect("Protocol error: got %d in response to rhosts auth", |
|
type); |
|
} |
|
/* |
* Try .rhosts or /etc/hosts.equiv authentication with RSA host |
* Try .rhosts or /etc/hosts.equiv authentication with RSA host |
* authentication. |
* authentication. |
*/ |
*/ |
|
|
/* NOTREACHED */ |
/* NOTREACHED */ |
|
|
success: |
success: |
|
#ifdef KRB5 |
|
/* Try Kerberos v5 TGT passing. */ |
|
if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) && |
|
options.kerberos_tgt_passing && context && auth_context) { |
|
if (options.cipher == SSH_CIPHER_NONE) |
|
logit("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!"); |
|
send_krb5_tgt(context, auth_context); |
|
} |
|
if (auth_context) |
|
krb5_auth_con_free(context, auth_context); |
|
if (context) |
|
krb5_free_context(context); |
|
#endif |
|
|
|
#ifdef AFS |
|
/* Try Kerberos v4 TGT passing if the server supports it. */ |
|
if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) && |
|
options.kerberos_tgt_passing) { |
|
if (options.cipher == SSH_CIPHER_NONE) |
|
logit("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!"); |
|
send_krb4_tgt(); |
|
} |
|
/* Try AFS token passing if the server supports it. */ |
|
if ((supported_authentications & (1 << SSH_PASS_AFS_TOKEN)) && |
|
options.afs_token_passing && k_hasafs()) { |
|
if (options.cipher == SSH_CIPHER_NONE) |
|
logit("WARNING: Encryption is disabled! Token will be transmitted in the clear!"); |
|
send_afs_tokens(); |
|
} |
|
#endif /* AFS */ |
|
|
return; /* need statement after label */ |
return; /* need statement after label */ |
} |
} |