krb5_error_code
kg_encrypt(krb5_context context, krb5_key key, int usage, krb5_pointer iv,
krb5_const_pointer in, krb5_pointer out, unsigned int length)
{
krb5_error_code code;
size_t blocksize;
krb5_data ivd, *pivd, inputd;
krb5_enc_data outputd;
if (iv) {
code = krb5_c_block_size(context, key->keyblock.enctype, &blocksize);
if (code)
return(code);
ivd.length = blocksize;
ivd.data = malloc(ivd.length);
if (ivd.data == NULL)
return ENOMEM;
memcpy(ivd.data, iv, ivd.length);
pivd = &ivd;
} else {
pivd = NULL;
}
inputd.length = length;
inputd.data = (char *)in;
outputd.ciphertext.length = length;
outputd.ciphertext.data = out;
code = krb5_k_encrypt(context, key, usage, pivd, &inputd, &outputd);
if (pivd != NULL)
free(pivd->data);
return code;
}
krb5_error_code KRB5_CALLCONV
krb5_decrypt(krb5_context context, krb5_const_pointer inptr,
krb5_pointer outptr, size_t size, krb5_encrypt_block *eblock,
krb5_pointer ivec)
{
krb5_enc_data inputd;
krb5_data outputd, ivecd;
size_t blocksize;
krb5_error_code ret;
if (ivec) {
if ((ret = krb5_c_block_size(context, eblock->key->enctype, &blocksize)))
return(ret);
ivecd.length = blocksize;
ivecd.data = ivec;
}
/* size is the length of the input ciphertext data */
inputd.enctype = eblock->key->enctype;
inputd.ciphertext.length = size;
inputd.ciphertext.data = inptr;
/* we don't really know how big this is, but the code tends to assume
that the output buffer size should be the same as the input
buffer size */
outputd.length = size;
outputd.data = outptr;
return(krb5_c_decrypt(context, eblock->key, 0, ivec?&ivecd:0,
&inputd, &outputd));
}
krb5_error_code krb5_decrypt_data(krb5_context context, krb5_keyblock *key,
krb5_pointer ivec, krb5_enc_data *enc_data,
krb5_data *data)
{
krb5_error_code ret;
krb5_data ivecd;
size_t blocksize;
if (ivec) {
if ((ret = krb5_c_block_size(context, key->enctype, &blocksize)))
return(ret);
ivecd.length = blocksize;
ivecd.data = ivec;
}
data->length = enc_data->ciphertext.length;
if ((data->data = (char *) malloc(data->length)) == NULL)
return(ENOMEM);
if ((ret = krb5_c_decrypt(context, key, 0, ivec?&ivecd:0, enc_data, data)))
free(data->data);
return(0);
}
krb5_error_code KRB5_CALLCONV
krb5_encrypt(krb5_context context, krb5_const_pointer inptr,
krb5_pointer outptr, size_t size, krb5_encrypt_block *eblock,
krb5_pointer ivec)
{
krb5_data inputd, ivecd;
krb5_enc_data outputd;
size_t blocksize, outlen;
krb5_error_code ret;
if (ivec) {
if ((ret = krb5_c_block_size(context, eblock->key->enctype, &blocksize)))
return(ret);
ivecd.length = blocksize;
ivecd.data = ivec;
}
/* size is the length of the input cleartext data */
inputd.length = size;
inputd.data = inptr;
/* The size of the output buffer isn't part of the old api. Not too
safe. So, we assume here that it's big enough. */
if ((ret = krb5_c_encrypt_length(context, eblock->key->enctype, size,
&outlen)))
return(ret);
outputd.ciphertext.length = outlen;
outputd.ciphertext.data = outptr;
return(krb5_c_encrypt(context, eblock->key, 0, ivec?&ivecd:0,
&inputd, &outputd));
}
krb5_error_code krb5_encrypt_data(krb5_context context, krb5_keyblock *key,
krb5_pointer ivec, krb5_data *data,
krb5_enc_data *enc_data)
{
krb5_error_code ret;
size_t enclen, blocksize;
krb5_data ivecd;
if ((ret = krb5_c_encrypt_length(context, key->enctype, data->length,
&enclen)))
return(ret);
if (ivec) {
if ((ret = krb5_c_block_size(context, key->enctype, &blocksize)))
return(ret);
ivecd.length = blocksize;
ivecd.data = ivec;
}
enc_data->magic = KV5M_ENC_DATA;
enc_data->kvno = 0;
enc_data->enctype = key->enctype;
enc_data->ciphertext.length = enclen;
if ((enc_data->ciphertext.data = malloc(enclen)) == NULL)
return(ENOMEM);
if ((ret = krb5_c_encrypt(context, key, 0, ivec?&ivecd:0, data, enc_data)))
free(enc_data->ciphertext.data);
return(ret);
}
int
kg_confounder_size(krb5_context context, krb5_enctype enctype)
{
krb5_error_code code;
size_t blocksize;
/* We special case rc4*/
if (enctype == ENCTYPE_ARCFOUR_HMAC || enctype == ENCTYPE_ARCFOUR_HMAC_EXP)
return 8;
code = krb5_c_block_size(context, enctype, &blocksize);
if (code)
return(-1); /* XXX */
return(blocksize);
}
krb5_error_code KRB5_CALLCONV
krb5_auth_con_initivector(krb5_context context, krb5_auth_context auth_context)
{
krb5_error_code ret;
krb5_enctype enctype;
if (auth_context->key) {
size_t blocksize;
enctype = krb5_k_key_enctype(context, auth_context->key);
if ((ret = krb5_c_block_size(context, enctype, &blocksize)))
return(ret);
if ((auth_context->i_vector = (krb5_pointer)calloc(1,blocksize))) {
return 0;
}
return ENOMEM;
}
return EINVAL; /* XXX need an error for no keyblock */
}
krb5_error_code
kg_decrypt_iov(krb5_context context, int proto, int dce_style, size_t ec,
size_t rrc, krb5_key key, int usage, krb5_pointer iv,
gss_iov_buffer_desc *iov, int iov_count)
{
krb5_error_code code;
size_t blocksize;
krb5_data ivd, *pivd;
size_t kiov_count;
krb5_crypto_iov *kiov;
if (iv) {
code = krb5_c_block_size(context, key->keyblock.enctype, &blocksize);
if (code)
return(code);
ivd.length = blocksize;
ivd.data = malloc(ivd.length);
if (ivd.data == NULL)
return ENOMEM;
memcpy(ivd.data, iv, ivd.length);
pivd = &ivd;
} else {
pivd = NULL;
}
code = kg_translate_iov(context, proto, dce_style, ec, rrc,
key->keyblock.enctype, iov, iov_count,
&kiov, &kiov_count);
if (code == 0) {
code = krb5_k_decrypt_iov(context, key, usage, pivd, kiov, kiov_count);
free(kiov);
}
if (pivd != NULL)
free(pivd->data);
return code;
}
static void
doit(int f,
struct sockaddr_storage *fromp,
krb5_context krb_context,
int encr_flag,
krb5_keytab keytab)
{
int p, t, on = 1;
char c;
char abuf[INET6_ADDRSTRLEN];
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6;
int fromplen;
in_port_t port;
struct termios tp;
boolean_t bad_port;
boolean_t no_name;
char rhost_addra[INET6_ADDRSTRLEN];
if (!(rlbuf = malloc(BUFSIZ))) {
syslog(LOG_ERR, "rlbuf malloc failed\n");
exit(EXIT_FAILURE);
}
(void) alarm(60);
if (read(f, &c, 1) != 1 || c != 0) {
syslog(LOG_ERR, "failed to receive protocol zero byte\n");
exit(EXIT_FAILURE);
}
(void) alarm(0);
if (fromp->ss_family == AF_INET) {
sin = (struct sockaddr_in *)fromp;
port = sin->sin_port = ntohs((ushort_t)sin->sin_port);
fromplen = sizeof (struct sockaddr_in);
if (!inet_ntop(AF_INET, &sin->sin_addr,
rhost_addra, sizeof (rhost_addra)))
goto badconversion;
} else if (fromp->ss_family == AF_INET6) {
sin6 = (struct sockaddr_in6 *)fromp;
port = sin6->sin6_port = ntohs((ushort_t)sin6->sin6_port);
fromplen = sizeof (struct sockaddr_in6);
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
struct in_addr ipv4_addr;
IN6_V4MAPPED_TO_INADDR(&sin6->sin6_addr,
&ipv4_addr);
if (!inet_ntop(AF_INET, &ipv4_addr, rhost_addra,
sizeof (rhost_addra)))
goto badconversion;
} else {
if (!inet_ntop(AF_INET6, &sin6->sin6_addr,
rhost_addra, sizeof (rhost_addra)))
goto badconversion;
}
} else {
syslog(LOG_ERR, "unknown address family %d\n",
fromp->ss_family);
fatal(f, "Permission denied");
}
/*
* Allow connections only from the "ephemeral" reserved
* ports(ports 512 - 1023) by checking the remote port
* because other utilities(e.g. in.ftpd) can be used to
* allow a unprivileged user to originate a connection
* from a privileged port and provide untrustworthy
* authentication.
*/
bad_port = (use_auth != KRB5_RECVAUTH_V5 &&
(port >= (in_port_t)IPPORT_RESERVED) ||
(port < (in_port_t)(IPPORT_RESERVED/2)));
no_name = getnameinfo((const struct sockaddr *) fromp,
fromplen, hostname, sizeof (hostname),
NULL, 0, 0) != 0;
if (no_name || bad_port) {
(void) strlcpy(abuf, rhost_addra, sizeof (abuf));
/* If no host name, use IP address for name later on. */
if (no_name)
(void) strlcpy(hostname, abuf, sizeof (hostname));
}
if (!no_name) {
/*
* Even if getnameinfo() succeeded, we still have to check
* for spoofing.
*/
check_address("rlogind", fromp, sin, sin6, rhost_addra,
hostname, sizeof (hostname));
}
if (bad_port) {
if (no_name)
syslog(LOG_NOTICE,
"connection from %s - bad port\n",
abuf);
else
syslog(LOG_NOTICE,
"connection from %s(%s) - bad port\n",
hostname, abuf);
fatal(f, "Permission denied");
}
if (use_auth == KRB5_RECVAUTH_V5) {
do_krb_login(f, rhost_addra, hostname,
krb_context, encr_flag, keytab);
if (krusername != NULL && strlen(krusername)) {
/*
* Kerberos Authentication succeeded,
* so set the proper program name to use
* with pam (important during 'cleanup'
* routine later).
*/
pam_prog_name = KRB5_PROG_NAME;
}
}
if (write(f, "", 1) != 1) {
syslog(LOG_NOTICE,
"send of the zero byte(to %s) failed:"
" cannot start data transfer mode\n",
(no_name ? abuf : hostname));
exit(EXIT_FAILURE);
}
if ((p = open("/dev/ptmx", O_RDWR)) == -1)
fatalperror(f, "cannot open /dev/ptmx");
if (grantpt(p) == -1)
fatal(f, "could not grant slave pty");
if (unlockpt(p) == -1)
fatal(f, "could not unlock slave pty");
if ((line = ptsname(p)) == NULL)
fatal(f, "could not enable slave pty");
if ((t = open(line, O_RDWR)) == -1)
fatal(f, "could not open slave pty");
if (ioctl(t, I_PUSH, "ptem") == -1)
fatalperror(f, "ioctl I_PUSH ptem");
if (ioctl(t, I_PUSH, "ldterm") == -1)
fatalperror(f, "ioctl I_PUSH ldterm");
if (ioctl(t, I_PUSH, "ttcompat") == -1)
fatalperror(f, "ioctl I_PUSH ttcompat");
/*
* POP the sockmod and push the rlmod module.
*
* Note that sockmod has to be removed since readstream assumes
* a "raw" TPI endpoint(e.g. it uses getmsg).
*/
if (removemod(f, "sockmod") < 0)
fatalperror(f, "couldn't remove sockmod");
if (encr_flag) {
if (ioctl(f, I_PUSH, "cryptmod") < 0)
fatalperror(f, "ioctl I_PUSH rlmod");
}
if (ioctl(f, I_PUSH, "rlmod") < 0)
fatalperror(f, "ioctl I_PUSH rlmod");
if (encr_flag) {
/*
* Make sure rlmod will pass unrecognized IOCTLs to cryptmod
*/
uchar_t passthru = 1;
struct strioctl rlmodctl;
rlmodctl.ic_cmd = CRYPTPASSTHRU;
rlmodctl.ic_timout = -1;
rlmodctl.ic_len = sizeof (uchar_t);
rlmodctl.ic_dp = (char *)&passthru;
if (ioctl(f, I_STR, &rlmodctl) < 0)
fatal(f, "ioctl CRYPTPASSTHRU failed\n");
}
/*
* readstream will do a getmsg till it receives
* M_PROTO type T_DATA_REQ from rloginmodopen()
* indicating all data on the stream prior to pushing rlmod has
* been drained at the stream head.
*/
if ((nsize = readstream(f, rlbuf, BUFSIZ)) < 0)
fatalperror(f, "readstream failed");
/*
* Make sure the pty doesn't modify the strings passed
* to login as part of the "rlogin protocol." The login
* program should set these flags to apropriate values
* after it has read the strings.
*/
if (ioctl(t, TCGETS, &tp) == -1)
fatalperror(f, "ioctl TCGETS");
tp.c_lflag &= ~(ECHO|ICANON);
tp.c_oflag &= ~(XTABS|OCRNL);
tp.c_iflag &= ~(IGNPAR|ICRNL);
if (ioctl(t, TCSETS, &tp) == -1)
fatalperror(f, "ioctl TCSETS");
/*
* System V ptys allow the TIOC{SG}WINSZ ioctl to be
* issued on the master side of the pty. Luckily, that's
* the only tty ioctl we need to do do, so we can close the
* slave side in the parent process after the fork.
*/
(void) ioctl(p, TIOCSWINSZ, &win);
pid = fork();
if (pid < 0)
fatalperror(f, "fork");
if (pid == 0) {
int tt;
struct utmpx ut;
/* System V login expects a utmp entry to already be there */
(void) memset(&ut, 0, sizeof (ut));
(void) strncpy(ut.ut_user, ".rlogin", sizeof (ut.ut_user));
(void) strncpy(ut.ut_line, line, sizeof (ut.ut_line));
ut.ut_pid = getpid();
ut.ut_id[0] = 'r';
ut.ut_id[1] = (char)SC_WILDC;
ut.ut_id[2] = (char)SC_WILDC;
ut.ut_id[3] = (char)SC_WILDC;
ut.ut_type = LOGIN_PROCESS;
ut.ut_exit.e_termination = 0;
ut.ut_exit.e_exit = 0;
(void) time(&ut.ut_tv.tv_sec);
if (makeutx(&ut) == NULL)
syslog(LOG_INFO, "in.rlogind:\tmakeutx failed");
/* controlling tty */
if (setsid() == -1)
fatalperror(f, "setsid");
if ((tt = open(line, O_RDWR)) == -1)
fatalperror(f, "could not re-open slave pty");
if (close(p) == -1)
fatalperror(f, "error closing pty master");
if (close(t) == -1)
fatalperror(f, "error closing pty slave"
" opened before session established");
/*
* If this fails we may or may not be able to output an
* error message.
*/
if (close(f) == -1)
fatalperror(f, "error closing deamon stdout");
if (dup2(tt, STDIN_FILENO) == -1 ||
dup2(tt, STDOUT_FILENO) == -1 ||
dup2(tt, STDERR_FILENO) == -1)
exit(EXIT_FAILURE); /* Disaster! No stderr! */
(void) close(tt);
if (use_auth == KRB5_RECVAUTH_V5 &&
krusername != NULL && strlen(krusername)) {
(void) execl(LOGIN_PROGRAM, "login",
"-d", line,
"-r", hostname,
"-u", krusername, /* KRB5 principal name */
"-s", pam_prog_name,
"-t", term, /* Remote Terminal */
"-U", rusername, /* Remote User */
"-R", KRB5_REPOSITORY_NAME,
lusername, /* local user */
NULL);
} else {
(void) execl(LOGIN_PROGRAM, "login",
"-d", line,
"-r", hostname,
NULL);
}
fatalperror(STDERR_FILENO, "/bin/login");
/*NOTREACHED*/
}
(void) close(t);
(void) ioctl(f, FIONBIO, &on);
(void) ioctl(p, FIONBIO, &on);
/*
* Must ignore SIGTTOU, otherwise we'll stop
* when we try and set slave pty's window shape
* (our controlling tty is the master pty).
* Likewise, we don't want any of the tty-generated
* signals from chars passing through.
*/
(void) sigset(SIGTSTP, SIG_IGN);
(void) sigset(SIGINT, SIG_IGN);
(void) sigset(SIGQUIT, SIG_IGN);
(void) sigset(SIGTTOU, SIG_IGN);
(void) sigset(SIGTTIN, SIG_IGN);
(void) sigset(SIGCHLD, cleanup);
(void) setpgrp();
if (encr_flag) {
krb5_data ivec, *ivptr;
uint_t ivec_usage;
stop_stream(f, CRYPT_ENCRYPT|CRYPT_DECRYPT);
/*
* Configure the STREAMS crypto module. For now,
* don't use any IV parameter. KCMDV0.2 support
* will require the use of Initialization Vectors
* for both encrypt and decrypt modes.
*/
if (kcmd_protocol == KCMD_OLD_PROTOCOL) {
if (session_key->enctype == ENCTYPE_DES_CBC_CRC) {
/*
* This is gross but necessary for MIT compat.
*/
ivec.length = session_key->length;
ivec.data = (char *)session_key->contents;
ivec_usage = IVEC_REUSE;
ivptr = &ivec;
} else {
ivptr = NULL; /* defaults to all 0's */
ivec_usage = IVEC_NEVER;
}
/*
* configure both sides of stream together
* since they share the same IV.
* This is what makes the OLD KCMD protocol
* less secure than the newer one - Bad ivecs.
*/
if (configure_stream(f, session_key,
CRYPT_ENCRYPT|CRYPT_DECRYPT,
ivptr, ivec_usage) != 0)
fatal(f, "Cannot initialize encryption -"
" exiting.\n");
} else {
size_t blocksize;
if (session_key->enctype == ENCTYPE_ARCFOUR_HMAC ||
session_key->enctype == ENCTYPE_ARCFOUR_HMAC_EXP) {
if (configure_stream(f, session_key,
CRYPT_ENCRYPT|CRYPT_DECRYPT,
NULL, IVEC_NEVER) != 0)
fatal(f,
"Cannot initialize encryption -"
" exiting.\n");
goto startcrypto;
}
if (krb5_c_block_size(krb_context,
session_key->enctype,
&blocksize)) {
syslog(LOG_ERR, "Cannot determine blocksize "
"for encryption type %d",
session_key->enctype);
fatal(f, "Cannot determine blocksize "
"for encryption - exiting.\n");
}
ivec.data = (char *)malloc(blocksize);
ivec.length = blocksize;
if (ivec.data == NULL)
fatal(f, "memory error - exiting\n");
/*
* Following MIT convention -
* encrypt IV = 0x01 x blocksize
* decrypt IV = 0x00 x blocksize
* ivec_usage = IVEC_ONETIME
*
* configure_stream separately for encrypt and
* decrypt because there are 2 different IVs.
*
* AES uses 0's for IV.
*/
if (session_key->enctype ==
ENCTYPE_AES128_CTS_HMAC_SHA1_96 ||
session_key->enctype ==
ENCTYPE_AES256_CTS_HMAC_SHA1_96)
(void) memset(ivec.data, 0x00, blocksize);
else
(void) memset(ivec.data, 0x01, blocksize);
if (configure_stream(f, session_key, CRYPT_ENCRYPT,
&ivec, IVEC_ONETIME) != 0)
fatal(f, "Cannot initialize encryption -"
" exiting.\n");
(void) memset(ivec.data, 0x00, blocksize);
if (configure_stream(f, session_key, CRYPT_DECRYPT,
&ivec, IVEC_ONETIME) != 0)
fatal(f, "Cannot initialize encryption -"
" exiting.\n");
(void) free(ivec.data);
}
startcrypto:
start_stream(f, CRYPT_ENCRYPT);
start_stream(f, CRYPT_DECRYPT);
}
protocol(f, p, encr_flag);
cleanup(0);
/*NOTREACHED*/
badconversion:
fatalperror(f, "address conversion");
/*NOTREACHED*/
}
/*ARGSUSED*/
static krb5_error_code
krb5_mk_priv_basic(krb5_context context, const krb5_data *userdata, const krb5_keyblock *keyblock, krb5_replay_data *replaydata, krb5_address *local_addr, krb5_address *remote_addr, krb5_pointer i_vector, krb5_data *outbuf)
{
krb5_error_code retval;
krb5_priv privmsg;
krb5_priv_enc_part privmsg_enc_part;
krb5_data *scratch1, *scratch2, ivdata;
size_t blocksize, enclen;
privmsg.enc_part.kvno = 0; /* XXX allow user-set? */
privmsg.enc_part.enctype = keyblock->enctype;
privmsg_enc_part.user_data = *userdata;
privmsg_enc_part.s_address = local_addr;
privmsg_enc_part.r_address = remote_addr;
/* We should check too make sure one exists. */
privmsg_enc_part.timestamp = replaydata->timestamp;
privmsg_enc_part.usec = replaydata->usec;
privmsg_enc_part.seq_number = replaydata->seq;
/* start by encoding to-be-encrypted part of the message */
if ((retval = encode_krb5_enc_priv_part(&privmsg_enc_part, &scratch1)))
return retval;
/* put together an eblock for this encryption */
if ((retval = krb5_c_encrypt_length(context, keyblock->enctype,
scratch1->length, &enclen)))
goto clean_scratch;
privmsg.enc_part.ciphertext.length = enclen;
if (!(privmsg.enc_part.ciphertext.data =
malloc(privmsg.enc_part.ciphertext.length))) {
retval = ENOMEM;
goto clean_scratch;
}
/* call the encryption routine */
if (i_vector) {
if ((retval = krb5_c_block_size(context, keyblock->enctype,
&blocksize)))
goto clean_encpart;
ivdata.length = blocksize;
ivdata.data = i_vector;
}
if ((retval = krb5_c_encrypt(context, keyblock,
KRB5_KEYUSAGE_KRB_PRIV_ENCPART,
i_vector?&ivdata:0,
scratch1, &privmsg.enc_part)))
goto clean_encpart;
if ((retval = encode_krb5_priv(&privmsg, &scratch2)))
goto clean_encpart;
*outbuf = *scratch2;
krb5_xfree(scratch2);
retval = 0;
clean_encpart:
memset(privmsg.enc_part.ciphertext.data, 0,
privmsg.enc_part.ciphertext.length);
free(privmsg.enc_part.ciphertext.data);
privmsg.enc_part.ciphertext.length = 0;
privmsg.enc_part.ciphertext.data = 0;
clean_scratch:
memset(scratch1->data, 0, scratch1->length);
krb5_free_data(context, scratch1);
return retval;
}
int
ksm_rgenerate_out_msg(struct snmp_secmod_outgoing_params *parms)
{
krb5_auth_context auth_context = NULL;
krb5_error_code retcode;
krb5_ccache cc = NULL;
int retval = SNMPERR_SUCCESS;
krb5_data outdata, ivector;
krb5_keyblock *subkey = NULL;
#ifdef MIT_NEW_CRYPTO
krb5_data input;
krb5_enc_data output;
unsigned int numcksumtypes;
krb5_cksumtype *cksumtype_array;
#else /* MIT_NEW_CRYPTO */
krb5_encrypt_block eblock;
#endif /* MIT_NEW_CRYPTO */
size_t blocksize, encrypted_length;
unsigned char *encrypted_data = NULL;
int zero = 0, i;
u_char *cksum_pointer, *endp = *parms->wholeMsg;
krb5_cksumtype cksumtype;
krb5_checksum pdu_checksum;
u_char **wholeMsg = parms->wholeMsg;
size_t *offset = parms->wholeMsgOffset, seq_offset;
struct ksm_secStateRef *ksm_state = (struct ksm_secStateRef *)
parms->secStateRef;
int rc;
DEBUGMSGTL(("ksm", "Starting KSM processing\n"));
outdata.length = 0;
outdata.data = NULL;
ivector.length = 0;
ivector.data = NULL;
pdu_checksum.contents = NULL;
if (!ksm_state) {
/*
* If we don't have a ksm_state, then we're a request. Get a
* credential cache and build a ap_req.
*/
retcode = krb5_cc_default(kcontext, &cc);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_cc_default failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Set credential cache successfully\n"));
/*
* This seems odd, since we don't need this until later (or earlier,
* depending on how you look at it), but because the most likely
* errors are Kerberos at this point, I'll get this now to save
* time not encoding the rest of the packet.
*
* Also, we need the subkey to encrypt the PDU (if required).
*/
retcode =
krb5_mk_req(kcontext, &auth_context,
AP_OPTS_MUTUAL_REQUIRED | AP_OPTS_USE_SUBKEY,
(char *) service_name, parms->session->peername, NULL,
cc, &outdata);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_mk_req failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: ticket retrieved successfully for \"%s/%s\" "
"(may not be actual ticket sname)\n", service_name,
parms->session->peername));
} else {
/*
* Grab the auth_context from our security state reference
*/
auth_context = ksm_state->auth_context;
/*
* Bundle up an AP_REP. Note that we do this only when we
* have a security state reference (which means we're in an agent
* and we're sending a response).
*/
DEBUGMSGTL(("ksm", "KSM: Starting reply processing.\n"));
retcode = krb5_mk_rep(kcontext, auth_context, &outdata);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_mk_rep failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Finished with krb5_mk_rep()\n"));
}
/*
* If we have to encrypt the PDU, do that now
*/
if (parms->secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
DEBUGMSGTL(("ksm", "KSM: Starting PDU encryption.\n"));
/*
* It's weird -
*
* If we're on the manager, it's a local subkey (because that's in
* our AP_REQ)
*
* If we're on the agent, it's a remote subkey (because that comes
* FROM the received AP_REQ).
*/
if (ksm_state)
retcode = krb5_auth_con_getremotesubkey(kcontext, auth_context,
&subkey);
else
retcode = krb5_auth_con_getlocalsubkey(kcontext, auth_context,
&subkey);
if (retcode) {
DEBUGMSGTL(("ksm",
"KSM: krb5_auth_con_getlocalsubkey failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
/*
* Note that here we need to handle different things between the
* old and new crypto APIs. First, we need to get the final encrypted
* length of the PDU.
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_encrypt_length(kcontext, subkey->enctype,
parms->scopedPduLen,
&encrypted_length);
if (retcode) {
DEBUGMSGTL(("ksm",
"Encryption length calculation failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#else /* MIT_NEW_CRYPTO */
krb5_use_enctype(kcontext, &eblock, subkey->enctype);
retcode = krb5_process_key(kcontext, &eblock, subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_process_key failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
encrypted_length = krb5_encrypt_size(parms->scopedPduLen,
eblock.crypto_entry);
#endif /* MIT_NEW_CRYPTO */
encrypted_data = malloc(encrypted_length);
if (!encrypted_data) {
DEBUGMSGTL(("ksm",
"KSM: Unable to malloc %d bytes for encrypt "
"buffer: %s\n", parms->scopedPduLen,
strerror(errno)));
retval = SNMPERR_MALLOC;
#ifndef MIT_NEW_CRYPTO
krb5_finish_key(kcontext, &eblock);
#endif /* ! MIT_NEW_CRYPTO */
goto error;
}
/*
* We need to set up a blank initialization vector for the encryption.
* Use a block of all zero's (which is dependent on the block size
* of the encryption method).
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_block_size(kcontext, subkey->enctype, &blocksize);
if (retcode) {
DEBUGMSGTL(("ksm",
"Unable to determine crypto block size: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#else /* MIT_NEW_CRYPTO */
blocksize =
krb5_enctype_array[subkey->enctype]->system->block_length;
#endif /* MIT_NEW_CRYPTO */
ivector.data = malloc(blocksize);
if (!ivector.data) {
DEBUGMSGTL(("ksm", "Unable to allocate %d bytes for ivector\n",
blocksize));
retval = SNMPERR_MALLOC;
goto error;
}
ivector.length = blocksize;
memset(ivector.data, 0, blocksize);
/*
* Finally! Do the encryption!
*/
#ifdef MIT_NEW_CRYPTO
input.data = (char *) parms->scopedPdu;
input.length = parms->scopedPduLen;
output.ciphertext.data = (char *) encrypted_data;
output.ciphertext.length = encrypted_length;
retcode =
krb5_c_encrypt(kcontext, subkey, KSM_KEY_USAGE_ENCRYPTION,
&ivector, &input, &output);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_encrypt(kcontext, (krb5_pointer) parms->scopedPdu,
(krb5_pointer) encrypted_data,
parms->scopedPduLen, &eblock, ivector.data);
krb5_finish_key(kcontext, &eblock);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_encrypt failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
*offset = 0;
rc = asn_realloc_rbuild_string(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
encrypted_data,
encrypted_length);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building encrypted payload failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Encryption complete.\n"));
} else {
/*
* Plaintext PDU (not encrypted)
*/
if (*parms->wholeMsgLen < parms->scopedPduLen) {
DEBUGMSGTL(("ksm", "Not enough room for plaintext PDU.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
}
/*
* Start encoding the msgSecurityParameters
*
* For now, use 0 for the response hint
*/
DEBUGMSGTL(("ksm", "KSM: scopedPdu added to payload\n"));
seq_offset = *offset;
rc = asn_realloc_rbuild_int(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_INTEGER),
(long *) &zero, sizeof(zero));
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_string(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
(u_char *) outdata.data,
outdata.length);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm AP_REQ failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
/*
* Now, we need to pick the "right" checksum algorithm. For old
* crypto, just pick CKSUMTYPE_RSA_MD5_DES; for new crypto, pick
* one of the "approved" ones.
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_keyed_checksum_types(kcontext, subkey->enctype,
&numcksumtypes, &cksumtype_array);
if (retcode) {
DEBUGMSGTL(("ksm", "Unable to find appropriate keyed checksum: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
if (numcksumtypes <= 0) {
DEBUGMSGTL(("ksm", "We received a list of zero cksumtypes for this "
"enctype (%d)\n", subkey->enctype));
snmp_set_detail("No valid checksum type for this encryption type");
retval = SNMPERR_KRB5;
goto error;
}
/*
* It's not clear to me from the API which checksum you're supposed
* to support, so I'm taking a guess at the first one
*/
cksumtype = cksumtype_array[0];
krb5_free_cksumtypes(kcontext, cksumtype_array);
DEBUGMSGTL(("ksm", "KSM: Choosing checksum type of %d (subkey type "
"of %d)\n", cksumtype, subkey->enctype));
retcode = krb5_c_checksum_length(kcontext, cksumtype, &blocksize);
if (retcode) {
DEBUGMSGTL(("ksm", "Unable to determine checksum length: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
pdu_checksum.length = blocksize;
#else /* MIT_NEW_CRYPTO */
if (ksm_state)
cksumtype = ksm_state->cksumtype;
else
cksumtype = CKSUMTYPE_RSA_MD5_DES;
if (!is_keyed_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a keyed checksum\n",
cksumtype));
snmp_set_detail("Checksum is not a keyed checksum");
retval = SNMPERR_KRB5;
goto error;
}
if (!is_coll_proof_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a collision-proof "
"checksum\n", cksumtype));
snmp_set_detail("Checksum is not a collision-proof checksum");
retval = SNMPERR_KRB5;
goto error;
}
pdu_checksum.length = krb5_checksum_size(kcontext, cksumtype);
pdu_checksum.checksum_type = cksumtype;
#endif /* MIT_NEW_CRYPTO */
/*
* Note that here, we're just leaving blank space for the checksum;
* we remember where that is, and we'll fill it in later.
*/
*offset += pdu_checksum.length;
memset(*wholeMsg + *parms->wholeMsgLen - *offset, 0, pdu_checksum.length);
cksum_pointer = *wholeMsg + *parms->wholeMsgLen - *offset;
rc = asn_realloc_rbuild_header(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
pdu_checksum.length);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_int(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
(long *) &cksumtype,
sizeof(cksumtype));
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_sequence(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_SEQUENCE |
ASN_CONSTRUCTOR),
*offset - seq_offset);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
rc = asn_realloc_rbuild_header(wholeMsg, parms->wholeMsgLen,
parms->wholeMsgOffset, 1,
(u_char) (ASN_UNIVERSAL |
ASN_PRIMITIVE |
ASN_OCTET_STR),
*offset - seq_offset);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building ksm security parameters failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Security parameter encoding completed\n"));
/*
* We're done with the KSM security parameters - now we do the global
* header and wrap up the whole PDU.
*/
if (*parms->wholeMsgLen < parms->globalDataLen) {
DEBUGMSGTL(("ksm", "Building global data failed.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
*offset += parms->globalDataLen;
memcpy(*wholeMsg + *parms->wholeMsgLen - *offset,
parms->globalData, parms->globalDataLen);
rc = asn_realloc_rbuild_sequence(wholeMsg, parms->wholeMsgLen,
offset, 1,
(u_char) (ASN_SEQUENCE |
ASN_CONSTRUCTOR),
*offset);
if (rc == 0) {
DEBUGMSGTL(("ksm", "Building master packet sequence.\n"));
retval = SNMPERR_TOO_LONG;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: PDU master packet encoding complete.\n"));
/*
* Now we need to checksum the entire PDU (since it's built).
*/
pdu_checksum.contents = malloc(pdu_checksum.length);
if (!pdu_checksum.contents) {
DEBUGMSGTL(("ksm", "Unable to malloc %d bytes for checksum\n",
pdu_checksum.length));
retval = SNMPERR_MALLOC;
goto error;
}
/*
* If we didn't encrypt the packet, we haven't yet got the subkey.
* Get that now.
*/
if (!subkey) {
if (ksm_state)
retcode = krb5_auth_con_getremotesubkey(kcontext, auth_context,
&subkey);
else
retcode = krb5_auth_con_getlocalsubkey(kcontext, auth_context,
&subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_auth_con_getlocalsubkey failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
}
#ifdef MIT_NEW_CRYPTO
input.data = (char *) (*wholeMsg + *parms->wholeMsgLen - *offset);
input.length = *offset;
retcode = krb5_c_make_checksum(kcontext, cksumtype, subkey,
KSM_KEY_USAGE_CHECKSUM, &input,
&pdu_checksum);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_calculate_checksum(kcontext, cksumtype, *wholeMsg +
*parms->wholeMsgLen - *offset,
*offset,
(krb5_pointer) subkey->contents,
subkey->length, &pdu_checksum);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "Calculate checksum failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
DEBUGMSGTL(("ksm", "KSM: Checksum calculation complete.\n"));
memcpy(cksum_pointer, pdu_checksum.contents, pdu_checksum.length);
DEBUGMSGTL(("ksm", "KSM: Writing checksum of %d bytes at offset %d\n",
pdu_checksum.length, cksum_pointer - (*wholeMsg + 1)));
DEBUGMSGTL(("ksm", "KSM: Checksum:"));
for (i = 0; i < pdu_checksum.length; i++)
DEBUGMSG(("ksm", " %02x",
(unsigned int) pdu_checksum.contents[i]));
DEBUGMSG(("ksm", "\n"));
/*
* If we're _not_ called as part of a response (null ksm_state),
* then save the auth_context for later using our cache routines.
*/
if (!ksm_state) {
if ((retval = ksm_insert_cache(parms->pdu->msgid, auth_context,
(u_char *) parms->secName,
parms->secNameLen)) !=
SNMPERR_SUCCESS)
goto error;
auth_context = NULL;
}
DEBUGMSGTL(("ksm", "KSM processing complete!\n"));
error:
if (pdu_checksum.contents)
#ifdef MIT_NEW_CRYPTO
krb5_free_checksum_contents(kcontext, &pdu_checksum);
#else /* MIT_NEW_CRYPTO */
free(pdu_checksum.contents);
#endif /* MIT_NEW_CRYPTO */
if (ivector.data)
free(ivector.data);
if (subkey)
krb5_free_keyblock(kcontext, subkey);
if (encrypted_data)
free(encrypted_data);
if (cc)
krb5_cc_close(kcontext, cc);
if (auth_context && !ksm_state)
krb5_auth_con_free(kcontext, auth_context);
return retval;
}
/*
* krb5_auth_context_externalize() - Externalize the krb5_auth_context.
*/
static krb5_error_code
krb5_auth_context_externalize(krb5_context kcontext, krb5_pointer arg, krb5_octet **buffer, size_t *lenremain)
{
krb5_error_code kret;
krb5_auth_context auth_context;
size_t required;
krb5_octet *bp;
size_t remain;
size_t obuf;
krb5_int32 obuf32;
required = 0;
bp = *buffer;
remain = *lenremain;
kret = EINVAL;
if ((auth_context = (krb5_auth_context) arg)) {
kret = ENOMEM;
if (!krb5_auth_context_size(kcontext, arg, &required) &&
(required <= remain)) {
/* Write fixed portion */
(void) krb5_ser_pack_int32(KV5M_AUTH_CONTEXT, &bp, &remain);
(void) krb5_ser_pack_int32(auth_context->auth_context_flags,
&bp, &remain);
(void) krb5_ser_pack_int32(auth_context->remote_seq_number,
&bp, &remain);
(void) krb5_ser_pack_int32(auth_context->local_seq_number,
&bp, &remain);
(void) krb5_ser_pack_int32((krb5_int32) auth_context->req_cksumtype,
&bp, &remain);
(void) krb5_ser_pack_int32((krb5_int32) auth_context->safe_cksumtype,
&bp, &remain);
kret = 0;
/* Now figure out the number of bytes for i_vector and write it */
if (auth_context->i_vector) {
kret = krb5_c_block_size(kcontext,
auth_context->keyblock->enctype,
&obuf);
} else {
obuf = 0;
}
/* Convert to signed 32 bit integer */
obuf32 = obuf;
if (kret == 0 && obuf != obuf32)
kret = EINVAL;
if (!kret)
(void) krb5_ser_pack_int32(obuf32, &bp, &remain);
/* Now copy i_vector */
if (!kret && auth_context->i_vector)
(void) krb5_ser_pack_bytes(auth_context->i_vector,
obuf,
&bp, &remain);
/* Now handle remote_addr, if appropriate */
if (!kret && auth_context->remote_addr) {
(void) krb5_ser_pack_int32(TOKEN_RADDR, &bp, &remain);
kret = krb5_externalize_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer)
auth_context->remote_addr,
&bp,
&remain);
}
/* Now handle remote_port, if appropriate */
if (!kret && auth_context->remote_port) {
(void) krb5_ser_pack_int32(TOKEN_RPORT, &bp, &remain);
kret = krb5_externalize_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer)
auth_context->remote_addr,
&bp,
&remain);
}
/* Now handle local_addr, if appropriate */
if (!kret && auth_context->local_addr) {
(void) krb5_ser_pack_int32(TOKEN_LADDR, &bp, &remain);
kret = krb5_externalize_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer)
auth_context->local_addr,
&bp,
&remain);
}
/* Now handle local_port, if appropriate */
if (!kret && auth_context->local_port) {
(void) krb5_ser_pack_int32(TOKEN_LPORT, &bp, &remain);
kret = krb5_externalize_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer)
auth_context->local_addr,
&bp,
&remain);
}
/* Now handle keyblock, if appropriate */
if (!kret && auth_context->keyblock) {
(void) krb5_ser_pack_int32(TOKEN_KEYBLOCK, &bp, &remain);
kret = krb5_externalize_opaque(kcontext,
KV5M_KEYBLOCK,
(krb5_pointer)
auth_context->keyblock,
&bp,
&remain);
}
/* Now handle subkey, if appropriate */
if (!kret && auth_context->send_subkey) {
(void) krb5_ser_pack_int32(TOKEN_LSKBLOCK, &bp, &remain);
kret = krb5_externalize_opaque(kcontext,
KV5M_KEYBLOCK,
(krb5_pointer)
auth_context->send_subkey,
&bp,
&remain);
}
/* Now handle subkey, if appropriate */
if (!kret && auth_context->recv_subkey) {
(void) krb5_ser_pack_int32(TOKEN_RSKBLOCK, &bp, &remain);
kret = krb5_externalize_opaque(kcontext,
KV5M_KEYBLOCK,
(krb5_pointer)
auth_context->recv_subkey,
&bp,
&remain);
}
/* Now handle authentp, if appropriate */
if (!kret && auth_context->authentp)
kret = krb5_externalize_opaque(kcontext,
KV5M_AUTHENTICATOR,
(krb5_pointer)
auth_context->authentp,
&bp,
&remain);
/*
* If we were successful, write trailer then update the pointer and
* remaining length;
*/
if (!kret) {
/* Write our trailer */
(void) krb5_ser_pack_int32(KV5M_AUTH_CONTEXT, &bp, &remain);
*buffer = bp;
*lenremain = remain;
}
}
}
return(kret);
}
int Condor_Auth_Kerberos :: unwrap(char* input,
int /* input_len */,
char*& output,
int& output_len)
{
krb5_error_code code;
krb5_data out_data;
krb5_enc_data enc_data;
int index = 0, tmp;
size_t blocksize;
out_data.data = 0;
out_data.length = 0;
memcpy(&tmp, input, sizeof(enc_data.enctype));
enc_data.enctype = ntohl(tmp);
index += sizeof(enc_data.enctype);
memcpy(&tmp, input + index, sizeof(enc_data.kvno));
enc_data.kvno = ntohl(tmp);
index += sizeof(enc_data.kvno);
memcpy(&tmp, input + index, sizeof(enc_data.ciphertext.length));
enc_data.ciphertext.length = ntohl(tmp);
index += sizeof(enc_data.ciphertext.length);
enc_data.ciphertext.data = input + index;
// DEBUG
dprintf (D_FULLDEBUG, "KERBEROS: input.enctype (%i) and session.enctype (%i)\n",
enc_data.enctype, sessionKey_->enctype);
// make a blank initialization vector
code = krb5_c_block_size(krb_context_, sessionKey_->enctype, &blocksize);
if (code) {
dprintf(D_ALWAYS, "AUTH_ERROR: %s\n", error_message(code));
}
out_data.length = enc_data.ciphertext.length;
out_data.data = (char*)malloc(out_data.length);
if ((code = krb5_c_decrypt(krb_context_, sessionKey_, 1024, /* key usage */
0, &enc_data, &out_data))!=0) { /* 0 = no ivec */
//if (code = krb5_decrypt_data(krb_context_, sessionKey_, 0, &enc_data, &out_data)) {
output_len = 0;
output = 0;
dprintf( D_ALWAYS, "KERBEROS: %s\n", error_message(code) );
if (out_data.data) {
free(out_data.data);
}
return false;
}
output_len = out_data.length;
output = (char *) malloc(output_len);
memcpy(output, out_data.data, output_len);
if (out_data.data) {
free(out_data.data);
}
return true;
}
int Condor_Auth_Kerberos :: wrap(char* input,
int input_len,
char*& output,
int& output_len)
{
krb5_error_code code;
krb5_data in_data;
krb5_enc_data out_data;
int index, tmp;
size_t blocksize, encrypted_length;
char* encrypted_data = 0;
// make a blank initialization vector
code = krb5_c_block_size(krb_context_, sessionKey_->enctype, &blocksize);
if (code) {
// err
}
// Make the input buffer
in_data.data = input;
in_data.length = input_len;
// Make the output buffer
code = krb5_c_encrypt_length(krb_context_, sessionKey_->enctype, input_len, &encrypted_length);
if(code) {
// err
}
encrypted_data = (char*)malloc(encrypted_length);
if (!encrypted_length) {
// err
}
out_data.ciphertext.data = (char*)encrypted_data;
out_data.ciphertext.length = encrypted_length;
if ((code = krb5_c_encrypt(krb_context_, sessionKey_, 1024, /* key usage */
0, &in_data, &out_data)) != 0) { /* 0 = no ivec */
output = 0;
output_len = 0;
if (out_data.ciphertext.data) {
free(out_data.ciphertext.data);
}
dprintf( D_ALWAYS, "KERBEROS: %s\n", error_message(code) );
return false;
}
output_len = sizeof(out_data.enctype) +
sizeof(out_data.kvno) +
sizeof(out_data.ciphertext.length) +
out_data.ciphertext.length;
output = (char *) malloc(output_len);
index = 0;
tmp = htonl(out_data.enctype);
memcpy(output + index, &tmp, sizeof(out_data.enctype));
index += sizeof(out_data.enctype);
tmp = htonl(out_data.kvno);
memcpy(output + index, &tmp, sizeof(out_data.kvno));
index += sizeof(out_data.kvno);
tmp = htonl(out_data.ciphertext.length);
memcpy(output + index, &tmp, sizeof(out_data.ciphertext.length));
index += sizeof(out_data.ciphertext.length);
if (out_data.ciphertext.data) {
memcpy(output + index, out_data.ciphertext.data,
out_data.ciphertext.length);
free(out_data.ciphertext.data);
}
return TRUE;
}
OM_uint32
kg_seal_iov_length(OM_uint32 *minor_status,
gss_ctx_id_t context_handle,
int conf_req_flag,
gss_qop_t qop_req,
int *conf_state,
gss_iov_buffer_desc *iov,
int iov_count)
{
krb5_gss_ctx_id_rec *ctx;
gss_iov_buffer_t header, trailer, padding;
size_t data_length, assoc_data_length;
size_t gss_headerlen, gss_padlen, gss_trailerlen;
unsigned int k5_headerlen = 0, k5_trailerlen = 0, k5_padlen = 0;
krb5_error_code code;
krb5_context context;
int dce_style;
if (qop_req != GSS_C_QOP_DEFAULT) {
*minor_status = (OM_uint32)G_UNKNOWN_QOP;
return GSS_S_FAILURE;
}
if (!kg_validate_ctx_id(context_handle)) {
*minor_status = (OM_uint32)G_VALIDATE_FAILED;
return GSS_S_NO_CONTEXT;
}
ctx = (krb5_gss_ctx_id_rec *)context_handle;
if (!ctx->established) {
*minor_status = KG_CTX_INCOMPLETE;
return GSS_S_NO_CONTEXT;
}
header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
if (header == NULL) {
*minor_status = EINVAL;
return GSS_S_FAILURE;
}
INIT_IOV_DATA(header);
trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
if (trailer != NULL) {
INIT_IOV_DATA(trailer);
}
dce_style = ((ctx->gss_flags & GSS_C_DCE_STYLE) != 0);
/* For CFX, EC is used instead of padding, and is placed in header or trailer */
padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
if (padding == NULL) {
if (conf_req_flag && ctx->proto == 0 && !dce_style) {
*minor_status = EINVAL;
return GSS_S_FAILURE;
}
} else {
INIT_IOV_DATA(padding);
}
kg_iov_msglen(iov, iov_count, &data_length, &assoc_data_length);
if (conf_req_flag && kg_integ_only_iov(iov, iov_count))
conf_req_flag = FALSE;
context = ctx->k5_context;
gss_headerlen = gss_padlen = gss_trailerlen = 0;
if (ctx->proto == 1) {
krb5_enctype enctype;
size_t ec;
if (ctx->have_acceptor_subkey)
enctype = ctx->acceptor_subkey->enctype;
else
enctype = ctx->subkey->enctype;
code = krb5_c_crypto_length(context, enctype,
conf_req_flag ?
KRB5_CRYPTO_TYPE_TRAILER : KRB5_CRYPTO_TYPE_CHECKSUM,
&k5_trailerlen);
if (code != 0) {
*minor_status = code;
return GSS_S_FAILURE;
}
if (conf_req_flag) {
code = krb5_c_crypto_length(context, enctype, KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
if (code != 0) {
*minor_status = code;
return GSS_S_FAILURE;
}
}
gss_headerlen = 16; /* Header */
if (conf_req_flag) {
gss_headerlen += k5_headerlen; /* Kerb-Header */
gss_trailerlen = 16 /* E(Header) */ + k5_trailerlen; /* Kerb-Trailer */
code = krb5_c_padding_length(context, enctype,
data_length - assoc_data_length + 16 /* E(Header) */, &k5_padlen);
if (code != 0) {
*minor_status = code;
return GSS_S_FAILURE;
}
if (k5_padlen == 0 && dce_style) {
/* Windows rejects AEAD tokens with non-zero EC */
code = krb5_c_block_size(context, enctype, &ec);
if (code != 0) {
*minor_status = code;
return GSS_S_FAILURE;
}
} else
ec = k5_padlen;
gss_trailerlen += ec;
} else {
gss_trailerlen = k5_trailerlen; /* Kerb-Checksum */
}
} else if (!dce_style) {
k5_padlen = (ctx->sealalg == SEAL_ALG_MICROSOFT_RC4) ? 1 : 8;
if (k5_padlen == 1)
gss_padlen = 1;
else
gss_padlen = k5_padlen - ((data_length - assoc_data_length) % k5_padlen);
}
data_length += gss_padlen;
if (ctx->proto == 0) {
/* Header | Checksum | Confounder | Data | Pad */
size_t data_size;
k5_headerlen = kg_confounder_size(context, ctx->enc);
data_size = 14 /* Header */ + ctx->cksum_size + k5_headerlen;
if (!dce_style)
data_size += data_length;
gss_headerlen = g_token_size(ctx->mech_used, data_size);
/* g_token_size() will include data_size as well as the overhead, so
* subtract data_length just to get the overhead (ie. token size) */
if (!dce_style)
gss_headerlen -= data_length;
}
if (minor_status != NULL)
*minor_status = 0;
if (trailer == NULL)
gss_headerlen += gss_trailerlen;
else
trailer->buffer.length = gss_trailerlen;
assert(gss_padlen == 0 || padding != NULL);
if (padding != NULL)
padding->buffer.length = gss_padlen;
header->buffer.length = gss_headerlen;
if (conf_state != NULL)
*conf_state = conf_req_flag;
return GSS_S_COMPLETE;
}
static krb5_error_code
krb5_rd_priv_basic(krb5_context context, const krb5_data *inbuf,
const krb5_keyblock *keyblock,
const krb5_address *local_addr,
const krb5_address *remote_addr, krb5_pointer i_vector,
krb5_replay_data *replaydata, krb5_data *outbuf)
{
krb5_error_code retval;
krb5_priv * privmsg;
krb5_data scratch;
krb5_priv_enc_part * privmsg_enc_part;
size_t blocksize;
krb5_data ivdata;
if (!krb5_is_krb_priv(inbuf))
return KRB5KRB_AP_ERR_MSG_TYPE;
/* decode private message */
if ((retval = decode_krb5_priv(inbuf, &privmsg)))
return retval;
if (i_vector) {
if ((retval = krb5_c_block_size(context, keyblock->enctype,
&blocksize)))
goto cleanup_privmsg;
ivdata.length = blocksize;
ivdata.data = i_vector;
}
scratch.length = privmsg->enc_part.ciphertext.length;
if (!(scratch.data = malloc(scratch.length))) {
retval = ENOMEM;
goto cleanup_privmsg;
}
if ((retval = krb5_c_decrypt(context, keyblock,
KRB5_KEYUSAGE_KRB_PRIV_ENCPART,
i_vector?&ivdata:0,
&privmsg->enc_part, &scratch)))
goto cleanup_scratch;
/* now decode the decrypted stuff */
if ((retval = decode_krb5_enc_priv_part(&scratch, &privmsg_enc_part)))
goto cleanup_scratch;
if (!krb5_address_compare(context,remote_addr,privmsg_enc_part->s_address)){
retval = KRB5KRB_AP_ERR_BADADDR;
goto cleanup_data;
}
if (privmsg_enc_part->r_address) {
if (local_addr) {
if (!krb5_address_compare(context, local_addr,
privmsg_enc_part->r_address)) {
retval = KRB5KRB_AP_ERR_BADADDR;
goto cleanup_data;
}
} else {
krb5_address **our_addrs;
if ((retval = krb5_os_localaddr(context, &our_addrs))) {
goto cleanup_data;
}
if (!krb5_address_search(context, privmsg_enc_part->r_address,
our_addrs)) {
krb5_free_addresses(context, our_addrs);
retval = KRB5KRB_AP_ERR_BADADDR;
goto cleanup_data;
}
krb5_free_addresses(context, our_addrs);
}
}
replaydata->timestamp = privmsg_enc_part->timestamp;
replaydata->usec = privmsg_enc_part->usec;
replaydata->seq = privmsg_enc_part->seq_number;
/* everything is ok - return data to the user */
*outbuf = privmsg_enc_part->user_data;
retval = 0;
cleanup_data:;
if (retval == 0)
privmsg_enc_part->user_data.data = 0;
krb5_free_priv_enc_part(context, privmsg_enc_part);
cleanup_scratch:;
memset(scratch.data, 0, scratch.length);
free(scratch.data);
cleanup_privmsg:;
free(privmsg->enc_part.ciphertext.data);
free(privmsg);
return retval;
}
krb5_error_code
gss_krb5int_make_seal_token_v3_iov(krb5_context context,
krb5_gss_ctx_id_rec *ctx,
int conf_req_flag,
int *conf_state,
gss_iov_buffer_desc *iov,
int iov_count,
int toktype)
{
krb5_error_code code = 0;
gss_iov_buffer_t header;
gss_iov_buffer_t padding;
gss_iov_buffer_t trailer;
unsigned char acceptor_flag;
unsigned short tok_id;
unsigned char *outbuf = NULL;
unsigned char *tbuf = NULL;
int key_usage;
size_t rrc = 0;
unsigned int gss_headerlen, gss_trailerlen;
krb5_key key;
krb5_cksumtype cksumtype;
size_t data_length, assoc_data_length;
assert(ctx->big_endian == 0);
assert(ctx->proto == 1);
acceptor_flag = ctx->initiate ? 0 : FLAG_SENDER_IS_ACCEPTOR;
key_usage = (toktype == KG_TOK_WRAP_MSG
? (ctx->initiate
? KG_USAGE_INITIATOR_SEAL
: KG_USAGE_ACCEPTOR_SEAL)
: (ctx->initiate
? KG_USAGE_INITIATOR_SIGN
: KG_USAGE_ACCEPTOR_SIGN));
if (ctx->have_acceptor_subkey) {
key = ctx->acceptor_subkey;
cksumtype = ctx->acceptor_subkey_cksumtype;
} else {
key = ctx->subkey;
cksumtype = ctx->cksumtype;
}
assert(key != NULL);
assert(cksumtype != 0);
kg_iov_msglen(iov, iov_count, &data_length, &assoc_data_length);
header = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_HEADER);
if (header == NULL)
return EINVAL;
padding = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_PADDING);
if (padding != NULL)
padding->buffer.length = 0;
trailer = kg_locate_iov(iov, iov_count, GSS_IOV_BUFFER_TYPE_TRAILER);
if (toktype == KG_TOK_WRAP_MSG && conf_req_flag) {
unsigned int k5_headerlen, k5_trailerlen, k5_padlen;
size_t ec = 0;
size_t conf_data_length = data_length - assoc_data_length;
code = krb5_c_crypto_length(context, key->keyblock.enctype,
KRB5_CRYPTO_TYPE_HEADER, &k5_headerlen);
if (code != 0)
goto cleanup;
code = krb5_c_padding_length(context, key->keyblock.enctype,
conf_data_length + 16 /* E(Header) */, &k5_padlen);
if (code != 0)
goto cleanup;
if (k5_padlen == 0 && (ctx->gss_flags & GSS_C_DCE_STYLE)) {
/* Windows rejects AEAD tokens with non-zero EC */
code = krb5_c_block_size(context, key->keyblock.enctype, &ec);
if (code != 0)
goto cleanup;
} else
ec = k5_padlen;
code = krb5_c_crypto_length(context, key->keyblock.enctype,
KRB5_CRYPTO_TYPE_TRAILER, &k5_trailerlen);
if (code != 0)
goto cleanup;
gss_headerlen = 16 /* Header */ + k5_headerlen;
gss_trailerlen = ec + 16 /* E(Header) */ + k5_trailerlen;
if (trailer == NULL) {
rrc = gss_trailerlen;
/* Workaround for Windows bug where it rotates by EC + RRC */
if (ctx->gss_flags & GSS_C_DCE_STYLE)
rrc -= ec;
gss_headerlen += gss_trailerlen;
}
if (header->type & GSS_IOV_BUFFER_FLAG_ALLOCATE) {
code = kg_allocate_iov(header, (size_t) gss_headerlen);
} else if (header->buffer.length < gss_headerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
outbuf = (unsigned char *)header->buffer.value;
header->buffer.length = (size_t) gss_headerlen;
if (trailer != NULL) {
if (trailer->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
else if (trailer->buffer.length < gss_trailerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
trailer->buffer.length = (size_t) gss_trailerlen;
}
/* TOK_ID */
store_16_be(KG2_TOK_WRAP_MSG, outbuf);
/* flags */
outbuf[2] = (acceptor_flag
| (conf_req_flag ? FLAG_WRAP_CONFIDENTIAL : 0)
| (ctx->have_acceptor_subkey ? FLAG_ACCEPTOR_SUBKEY : 0));
/* filler */
outbuf[3] = 0xFF;
/* EC */
store_16_be(ec, outbuf + 4);
/* RRC */
store_16_be(0, outbuf + 6);
store_64_be(ctx->seq_send, outbuf + 8);
/* EC | copy of header to be encrypted, located in (possibly rotated) trailer */
if (trailer == NULL)
tbuf = (unsigned char *)header->buffer.value + 16; /* Header */
else
tbuf = (unsigned char *)trailer->buffer.value;
memset(tbuf, 0xFF, ec);
memcpy(tbuf + ec, header->buffer.value, 16);
code = kg_encrypt_iov(context, ctx->proto,
((ctx->gss_flags & GSS_C_DCE_STYLE) != 0),
ec, rrc, key, key_usage, 0, iov, iov_count);
if (code != 0)
goto cleanup;
/* RRC */
store_16_be(rrc, outbuf + 6);
ctx->seq_send++;
} else if (toktype == KG_TOK_WRAP_MSG && !conf_req_flag) {
tok_id = KG2_TOK_WRAP_MSG;
wrap_with_checksum:
gss_headerlen = 16;
code = krb5_c_crypto_length(context, key->keyblock.enctype,
KRB5_CRYPTO_TYPE_CHECKSUM,
&gss_trailerlen);
if (code != 0)
goto cleanup;
assert(gss_trailerlen <= 0xFFFF);
if (trailer == NULL) {
rrc = gss_trailerlen;
gss_headerlen += gss_trailerlen;
}
if (header->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
code = kg_allocate_iov(header, (size_t) gss_headerlen);
else if (header->buffer.length < gss_headerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
outbuf = (unsigned char *)header->buffer.value;
header->buffer.length = (size_t) gss_headerlen;
if (trailer != NULL) {
if (trailer->type & GSS_IOV_BUFFER_FLAG_ALLOCATE)
code = kg_allocate_iov(trailer, (size_t) gss_trailerlen);
else if (trailer->buffer.length < gss_trailerlen)
code = KRB5_BAD_MSIZE;
if (code != 0)
goto cleanup;
trailer->buffer.length = (size_t) gss_trailerlen;
}
/* TOK_ID */
store_16_be(tok_id, outbuf);
/* flags */
outbuf[2] = (acceptor_flag
| (ctx->have_acceptor_subkey ? FLAG_ACCEPTOR_SUBKEY : 0));
/* filler */
outbuf[3] = 0xFF;
if (toktype == KG_TOK_WRAP_MSG) {
/* Use 0 for checksum calculation, substitute
* checksum length later.
*/
/* EC */
store_16_be(0, outbuf + 4);
/* RRC */
store_16_be(0, outbuf + 6);
} else {
/* MIC and DEL store 0xFF in EC and RRC */
store_16_be(0xFFFF, outbuf + 4);
store_16_be(0xFFFF, outbuf + 6);
}
store_64_be(ctx->seq_send, outbuf + 8);
code = kg_make_checksum_iov_v3(context, cksumtype,
rrc, key, key_usage,
iov, iov_count);
if (code != 0)
goto cleanup;
ctx->seq_send++;
if (toktype == KG_TOK_WRAP_MSG) {
/* Fix up EC field */
store_16_be(gss_trailerlen, outbuf + 4);
/* Fix up RRC field */
store_16_be(rrc, outbuf + 6);
}
} else if (toktype == KG_TOK_MIC_MSG) {
tok_id = KG2_TOK_MIC_MSG;
trailer = NULL;
goto wrap_with_checksum;
} else if (toktype == KG_TOK_DEL_CTX) {
tok_id = KG2_TOK_DEL_CTX;
goto wrap_with_checksum;
} else {
abort();
}
code = 0;
if (conf_state != NULL)
*conf_state = conf_req_flag;
cleanup:
if (code != 0)
kg_release_iov(iov, iov_count);
return code;
}
/*
* krb5_auth_context_size() - Determine the size required to externalize
* the krb5_auth_context.
*/
static krb5_error_code
krb5_auth_context_size(krb5_context kcontext, krb5_pointer arg, size_t *sizep)
{
krb5_error_code kret;
krb5_auth_context auth_context;
size_t required;
/*
* krb5_auth_context requires at minimum:
* krb5_int32 for KV5M_AUTH_CONTEXT
* krb5_int32 for auth_context_flags
* krb5_int32 for remote_seq_number
* krb5_int32 for local_seq_number
* krb5_int32 for req_cksumtype
* krb5_int32 for safe_cksumtype
* krb5_int32 for size of i_vector
* krb5_int32 for KV5M_AUTH_CONTEXT
*/
kret = EINVAL;
if ((auth_context = (krb5_auth_context) arg)) {
kret = 0;
/* Calculate size required by i_vector - ptooey */
if (auth_context->i_vector && auth_context->keyblock) {
kret = krb5_c_block_size(kcontext, auth_context->keyblock->enctype,
&required);
} else {
required = 0;
}
required += sizeof(krb5_int32)*8;
/* Calculate size required by remote_addr, if appropriate */
if (!kret && auth_context->remote_addr) {
kret = krb5_size_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer) auth_context->remote_addr,
&required);
if (!kret)
required += sizeof(krb5_int32);
}
/* Calculate size required by remote_port, if appropriate */
if (!kret && auth_context->remote_port) {
kret = krb5_size_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer) auth_context->remote_port,
&required);
if (!kret)
required += sizeof(krb5_int32);
}
/* Calculate size required by local_addr, if appropriate */
if (!kret && auth_context->local_addr) {
kret = krb5_size_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer) auth_context->local_addr,
&required);
if (!kret)
required += sizeof(krb5_int32);
}
/* Calculate size required by local_port, if appropriate */
if (!kret && auth_context->local_port) {
kret = krb5_size_opaque(kcontext,
KV5M_ADDRESS,
(krb5_pointer) auth_context->local_port,
&required);
if (!kret)
required += sizeof(krb5_int32);
}
/* Calculate size required by keyblock, if appropriate */
if (!kret && auth_context->keyblock) {
kret = krb5_size_opaque(kcontext,
KV5M_KEYBLOCK,
(krb5_pointer) auth_context->keyblock,
&required);
if (!kret)
required += sizeof(krb5_int32);
}
/* Calculate size required by send_subkey, if appropriate */
if (!kret && auth_context->send_subkey) {
kret = krb5_size_opaque(kcontext,
KV5M_KEYBLOCK,
(krb5_pointer) auth_context->send_subkey,
&required);
if (!kret)
required += sizeof(krb5_int32);
}
/* Calculate size required by recv_subkey, if appropriate */
if (!kret && auth_context->recv_subkey) {
kret = krb5_size_opaque(kcontext,
KV5M_KEYBLOCK,
(krb5_pointer) auth_context->recv_subkey,
&required);
if (!kret)
required += sizeof(krb5_int32);
}
/* Calculate size required by authentp, if appropriate */
if (!kret && auth_context->authentp)
kret = krb5_size_opaque(kcontext,
KV5M_AUTHENTICATOR,
(krb5_pointer) auth_context->authentp,
&required);
}
if (!kret)
*sizep += required;
return(kret);
}
int
ksm_process_in_msg(struct snmp_secmod_incoming_params *parms)
{
long temp;
krb5_cksumtype cksumtype;
krb5_auth_context auth_context = NULL;
krb5_error_code retcode;
krb5_checksum checksum;
krb5_data ap_req, ivector;
krb5_flags flags;
krb5_keyblock *subkey = NULL;
#ifdef MIT_NEW_CRYPTO
krb5_data input, output;
krb5_boolean valid;
krb5_enc_data in_crypt;
#else /* MIT_NEW_CRYPTO */
krb5_encrypt_block eblock;
#endif /* MIT_NEW_CRYPTO */
krb5_ticket *ticket = NULL;
int retval = SNMPERR_SUCCESS, response = 0;
size_t length =
parms->wholeMsgLen - (u_int) (parms->secParams - parms->wholeMsg);
u_char *current = parms->secParams, type;
size_t cksumlength, blocksize;
long hint;
char *cname;
struct ksm_secStateRef *ksm_state;
struct ksm_cache_entry *entry;
DEBUGMSGTL(("ksm", "Processing has begun\n"));
checksum.contents = NULL;
ap_req.data = NULL;
ivector.length = 0;
ivector.data = NULL;
/*
* First, parse the security parameters (because we need the subkey inside
* of the ticket to do anything
*/
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR),
"ksm first octet")) == NULL) {
DEBUGMSGTL(("ksm", "Initial security paramter parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_SEQUENCE | ASN_CONSTRUCTOR),
"ksm sequence")) == NULL) {
DEBUGMSGTL(("ksm",
"Security parameter sequence parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
if ((current = asn_parse_int(current, &length, &type, &temp,
sizeof(temp))) == NULL) {
DEBUGMSGTL(("ksm", "Security parameter checksum type parsing"
"failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
cksumtype = temp;
#ifdef MIT_NEW_CRYPTO
if (!krb5_c_valid_cksumtype(cksumtype)) {
DEBUGMSGTL(("ksm", "Invalid checksum type (%d)\n", cksumtype));
retval = SNMPERR_KRB5;
snmp_set_detail("Invalid checksum type");
goto error;
}
if (!krb5_c_is_keyed_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a keyed checksum\n",
cksumtype));
snmp_set_detail("Checksum is not a keyed checksum");
retval = SNMPERR_KRB5;
goto error;
}
if (!krb5_c_is_coll_proof_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a collision-proof "
"checksum\n", cksumtype));
snmp_set_detail("Checksum is not a collision-proof checksum");
retval = SNMPERR_KRB5;
goto error;
}
#else /* ! MIT_NEW_CRYPTO */
if (!valid_cksumtype(cksumtype)) {
DEBUGMSGTL(("ksm", "Invalid checksum type (%d)\n", cksumtype));
retval = SNMPERR_KRB5;
snmp_set_detail("Invalid checksum type");
goto error;
}
if (!is_keyed_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a keyed checksum\n",
cksumtype));
snmp_set_detail("Checksum is not a keyed checksum");
retval = SNMPERR_KRB5;
goto error;
}
if (!is_coll_proof_cksum(cksumtype)) {
DEBUGMSGTL(("ksm", "Checksum type %d is not a collision-proof "
"checksum\n", cksumtype));
snmp_set_detail("Checksum is not a collision-proof checksum");
retval = SNMPERR_KRB5;
goto error;
}
#endif /* MIT_NEW_CRYPTO */
checksum.checksum_type = cksumtype;
cksumlength = length;
if ((current = asn_parse_sequence(current, &cksumlength, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), "ksm checksum")) ==
NULL) {
DEBUGMSGTL(("ksm",
"Security parameter checksum parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
checksum.contents = malloc(cksumlength);
if (!checksum.contents) {
DEBUGMSGTL(("ksm", "Unable to malloc %d bytes for checksum.\n",
cksumlength));
retval = SNMPERR_MALLOC;
goto error;
}
memcpy(checksum.contents, current, cksumlength);
checksum.length = cksumlength;
checksum.checksum_type = cksumtype;
/*
* Zero out the checksum so the validation works correctly
*/
memset(current, 0, cksumlength);
current += cksumlength;
length = parms->wholeMsgLen - (u_int) (current - parms->wholeMsg);
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), "ksm ap_req")) ==
NULL) {
DEBUGMSGTL(("ksm", "KSM security parameter AP_REQ/REP parsing "
"failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
ap_req.length = length;
ap_req.data = malloc(length);
if (!ap_req.data) {
DEBUGMSGTL(("ksm",
"KSM unable to malloc %d bytes for AP_REQ/REP.\n",
length));
retval = SNMPERR_MALLOC;
goto error;
}
memcpy(ap_req.data, current, length);
current += length;
length = parms->wholeMsgLen - (u_int) (current - parms->wholeMsg);
if ((current = asn_parse_int(current, &length, &type, &hint,
sizeof(hint))) == NULL) {
DEBUGMSGTL(("ksm",
"KSM security parameter hint parsing failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
/*
* Okay! We've got it all! Now try decoding the damn ticket.
*
* But of course there's a WRINKLE! We need to figure out if we're
* processing a AP_REQ or an AP_REP. How do we do that? We're going
* to cheat, and look at the first couple of bytes (which is what
* the Kerberos library routines do anyway).
*
* If there are ever new Kerberos message formats, we'll need to fix
* this here.
*
* If it's a _response_, then we need to get the auth_context
* from our cache.
*/
if (ap_req.length
&& (ap_req.data[0] == 0x6e || ap_req.data[0] == 0x4e)) {
/*
* We need to initalize the authorization context, and set the
* replay cache in it (and initialize the replay cache if we
* haven't already
*/
retcode = krb5_auth_con_init(kcontext, &auth_context);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_auth_con_init failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
if (!rcache) {
krb5_data server;
server.data = "host";
server.length = strlen(server.data);
retcode = krb5_get_server_rcache(kcontext, &server, &rcache);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_get_server_rcache failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
}
retcode = krb5_auth_con_setrcache(kcontext, auth_context, rcache);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_auth_con_setrcache failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
retcode = krb5_rd_req(kcontext, &auth_context, &ap_req, NULL,
keytab, &flags, &ticket);
krb5_auth_con_setrcache(kcontext, auth_context, NULL);
if (retcode) {
DEBUGMSGTL(("ksm", "krb5_rd_req() failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
retcode =
krb5_unparse_name(kcontext, ticket->enc_part2->client, &cname);
if (retcode == 0) {
DEBUGMSGTL(("ksm", "KSM authenticated principal name: %s\n",
cname));
free(cname);
}
/*
* Check to make sure AP_OPTS_MUTUAL_REQUIRED was set
*/
if (!(flags & AP_OPTS_MUTUAL_REQUIRED)) {
DEBUGMSGTL(("ksm",
"KSM MUTUAL_REQUIRED not set in request!\n"));
retval = SNMPERR_KRB5;
snmp_set_detail("MUTUAL_REQUIRED not set in message");
goto error;
}
retcode =
krb5_auth_con_getremotesubkey(kcontext, auth_context, &subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM remote subkey retrieval failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
} else if (ap_req.length && (ap_req.data[0] == 0x6f ||
ap_req.data[0] == 0x4f)) {
/*
* Looks like a response; let's see if we've got that auth_context
* in our cache.
*/
krb5_ap_rep_enc_part *repl = NULL;
response = 1;
entry = ksm_get_cache(parms->pdu->msgid);
if (!entry) {
DEBUGMSGTL(("ksm",
"KSM: Unable to find auth_context for PDU with "
"message ID of %ld\n", parms->pdu->msgid));
retval = SNMPERR_KRB5;
goto error;
}
auth_context = entry->auth_context;
/*
* In that case, let's call the rd_rep function
*/
retcode = krb5_rd_rep(kcontext, auth_context, &ap_req, &repl);
if (repl)
krb5_free_ap_rep_enc_part(kcontext, repl);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM: krb5_rd_rep() failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
goto error;
}
DEBUGMSGTL(("ksm", "KSM: krb5_rd_rep() decoded successfully.\n"));
retcode =
krb5_auth_con_getlocalsubkey(kcontext, auth_context, &subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "Unable to retrieve local subkey: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail("Unable to retrieve local subkey");
goto error;
}
} else {
DEBUGMSGTL(("ksm", "Unknown Kerberos message type (%02x)\n",
ap_req.data[0]));
retval = SNMPERR_KRB5;
snmp_set_detail("Unknown Kerberos message type");
goto error;
}
#ifdef MIT_NEW_CRYPTO
input.data = (char *) parms->wholeMsg;
input.length = parms->wholeMsgLen;
retcode =
krb5_c_verify_checksum(kcontext, subkey, KSM_KEY_USAGE_CHECKSUM,
&input, &checksum, &valid);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_verify_checksum(kcontext, cksumtype, &checksum,
parms->wholeMsg, parms->wholeMsgLen,
(krb5_pointer) subkey->contents,
subkey->length);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "KSM checksum verification failed: %s\n",
error_message(retcode)));
retval = SNMPERR_KRB5;
snmp_set_detail(error_message(retcode));
goto error;
}
/*
* Don't ask me why they didn't simply return an error, but we have
* to check to see if "valid" is false.
*/
#ifdef MIT_NEW_CRYPTO
if (!valid) {
DEBUGMSGTL(("ksm", "Computed checksum did not match supplied "
"checksum!\n"));
retval = SNMPERR_KRB5;
snmp_set_detail
("Computed checksum did not match supplied checksum");
goto error;
}
#endif /* MIT_NEW_CRYPTO */
/*
* Handle an encrypted PDU. Note that it's an OCTET_STRING of the
* output of whatever Kerberos cryptosystem you're using (defined by
* the encryption type). Note that this is NOT the EncryptedData
* sequence - it's what goes in the "cipher" field of EncryptedData.
*/
if (parms->secLevel == SNMP_SEC_LEVEL_AUTHPRIV) {
if ((current = asn_parse_sequence(current, &length, &type,
(ASN_UNIVERSAL | ASN_PRIMITIVE |
ASN_OCTET_STR), "ksm pdu")) ==
NULL) {
DEBUGMSGTL(("ksm", "KSM sPDU octet decoding failed\n"));
retval = SNMPERR_ASN_PARSE_ERR;
goto error;
}
/*
* The PDU is now pointed at by "current", and the length is in
* "length".
*/
DEBUGMSGTL(("ksm", "KSM starting sPDU decode\n"));
/*
* We need to set up a blank initialization vector for the decryption.
* Use a block of all zero's (which is dependent on the block size
* of the encryption method).
*/
#ifdef MIT_NEW_CRYPTO
retcode = krb5_c_block_size(kcontext, subkey->enctype, &blocksize);
if (retcode) {
DEBUGMSGTL(("ksm",
"Unable to determine crypto block size: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#else /* MIT_NEW_CRYPTO */
blocksize =
krb5_enctype_array[subkey->enctype]->system->block_length;
#endif /* MIT_NEW_CRYPTO */
ivector.data = malloc(blocksize);
if (!ivector.data) {
DEBUGMSGTL(("ksm", "Unable to allocate %d bytes for ivector\n",
blocksize));
retval = SNMPERR_MALLOC;
goto error;
}
ivector.length = blocksize;
memset(ivector.data, 0, blocksize);
#ifndef MIT_NEW_CRYPTO
krb5_use_enctype(kcontext, &eblock, subkey->enctype);
retcode = krb5_process_key(kcontext, &eblock, subkey);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM key post-processing failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
#endif /* !MIT_NEW_CRYPTO */
if (length > *parms->scopedPduLen) {
DEBUGMSGTL(("ksm", "KSM not enough room - have %d bytes to "
"decrypt but only %d bytes available\n", length,
*parms->scopedPduLen));
retval = SNMPERR_TOO_LONG;
#ifndef MIT_NEW_CRYPTO
krb5_finish_key(kcontext, &eblock);
#endif /* ! MIT_NEW_CRYPTO */
goto error;
}
#ifdef MIT_NEW_CRYPTO
in_crypt.ciphertext.data = (char *) current;
in_crypt.ciphertext.length = length;
in_crypt.enctype = subkey->enctype;
output.data = (char *) *parms->scopedPdu;
output.length = *parms->scopedPduLen;
retcode =
krb5_c_decrypt(kcontext, subkey, KSM_KEY_USAGE_ENCRYPTION,
&ivector, &in_crypt, &output);
#else /* MIT_NEW_CRYPTO */
retcode = krb5_decrypt(kcontext, (krb5_pointer) current,
*parms->scopedPdu, length, &eblock,
ivector.data);
krb5_finish_key(kcontext, &eblock);
#endif /* MIT_NEW_CRYPTO */
if (retcode) {
DEBUGMSGTL(("ksm", "Decryption failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
*parms->scopedPduLen = length;
} else {
/*
* Clear PDU
*/
*parms->scopedPdu = current;
*parms->scopedPduLen =
parms->wholeMsgLen - (current - parms->wholeMsg);
}
/*
* A HUGE GROSS HACK
*/
*parms->maxSizeResponse = parms->maxMsgSize - 200;
DEBUGMSGTL(("ksm", "KSM processing complete\n"));
/*
* Set the secName to the right value (a hack for now). But that's
* only used for when we're processing a request, not a response.
*/
if (!response) {
retcode = krb5_unparse_name(kcontext, ticket->enc_part2->client,
&cname);
if (retcode) {
DEBUGMSGTL(("ksm", "KSM krb5_unparse_name failed: %s\n",
error_message(retcode)));
snmp_set_detail(error_message(retcode));
retval = SNMPERR_KRB5;
goto error;
}
if (strlen(cname) > *parms->secNameLen + 1) {
DEBUGMSGTL(("ksm",
"KSM: Principal length (%d) is too long (%d)\n",
strlen(cname), parms->secNameLen));
retval = SNMPERR_TOO_LONG;
free(cname);
goto error;
}
strcpy(parms->secName, cname);
*parms->secNameLen = strlen(cname);
free(cname);
/*
* Also, if we're not a response, keep around our auth_context so we
* can encode the reply message correctly
*/
ksm_state = SNMP_MALLOC_STRUCT(ksm_secStateRef);
if (!ksm_state) {
DEBUGMSGTL(("ksm", "KSM unable to malloc memory for "
"ksm_secStateRef\n"));
retval = SNMPERR_MALLOC;
goto error;
}
ksm_state->auth_context = auth_context;
auth_context = NULL;
ksm_state->cksumtype = cksumtype;
*parms->secStateRef = ksm_state;
} else {
/*
* We _still_ have to set the secName in process_in_msg(). Do
* that now with what we were passed in before (we cached it,
* remember?)
*/
memcpy(parms->secName, entry->secName, entry->secNameLen);
*parms->secNameLen = entry->secNameLen;
}
/*
* Just in case
*/
parms->secEngineID = (u_char *) "";
*parms->secEngineIDLen = 0;
auth_context = NULL; /* So we don't try to free it on success */
error:
if (retval == SNMPERR_ASN_PARSE_ERR &&
snmp_increment_statistic(STAT_SNMPINASNPARSEERRS) == 0)
DEBUGMSGTL(("ksm", "Failed to increment statistics.\n"));
if (subkey)
krb5_free_keyblock(kcontext, subkey);
if (checksum.contents)
free(checksum.contents);
if (ivector.data)
free(ivector.data);
if (ticket)
krb5_free_ticket(kcontext, ticket);
if (!response && auth_context)
krb5_auth_con_free(kcontext, auth_context);
if (ap_req.data)
free(ap_req.data);
return retval;
}
