diff options
Diffstat (limited to 'crypto/heimdal/appl/kx/krb4.c')
| -rw-r--r-- | crypto/heimdal/appl/kx/krb4.c | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/crypto/heimdal/appl/kx/krb4.c b/crypto/heimdal/appl/kx/krb4.c new file mode 100644 index 0000000..07852c9 --- /dev/null +++ b/crypto/heimdal/appl/kx/krb4.c @@ -0,0 +1,361 @@ +/* + * Copyright (c) 1995 - 2000 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "kx.h" + +RCSID("$Id: krb4.c,v 1.8 2000/10/08 13:19:22 assar Exp $"); + +#ifdef KRB4 + +struct krb4_kx_context { + des_cblock key; + des_key_schedule schedule; + AUTH_DAT auth; +}; + +typedef struct krb4_kx_context krb4_kx_context; + +/* + * Destroy the krb4 context in `c'. + */ + +static void +krb4_destroy (kx_context *c) +{ + memset (c->data, 0, sizeof(krb4_kx_context)); + free (c->data); +} + +/* + * Read the authentication information from `s' and return 0 if + * succesful, else -1. + */ + +static int +krb4_authenticate (kx_context *kc, int s) +{ + CREDENTIALS cred; + KTEXT_ST text; + MSG_DAT msg; + int status; + krb4_kx_context *c = (krb4_kx_context *)kc->data; + const char *host = kc->host; + +#ifdef HAVE_KRB_GET_OUR_IP_FOR_REALM + if (krb_get_config_bool("nat_in_use")) { + struct in_addr natAddr; + + if (krb_get_our_ip_for_realm(krb_realmofhost(kc->host), + &natAddr) == KSUCCESS + || krb_get_our_ip_for_realm (NULL, &natAddr) == KSUCCESS) + kc->thisaddr.sin_addr = natAddr; + } +#endif + + status = krb_sendauth (KOPT_DO_MUTUAL, s, &text, "rcmd", + (char *)host, krb_realmofhost (host), + getpid(), &msg, &cred, c->schedule, + &kc->thisaddr, &kc->thataddr, KX_VERSION); + if (status != KSUCCESS) { + warnx ("%s: %s\n", host, krb_get_err_text(status)); + return -1; + } + memcpy (c->key, cred.session, sizeof(des_cblock)); + return 0; +} + +/* + * Read a krb4 priv packet from `fd' into `buf' (of size `len'). + * Return the number of bytes read or 0 on EOF or -1 on error. + */ + +static ssize_t +krb4_read (kx_context *kc, + int fd, void *buf, size_t len) +{ + unsigned char tmp[4]; + ssize_t ret; + size_t l; + int status; + krb4_kx_context *c = (krb4_kx_context *)kc->data; + MSG_DAT msg; + + ret = krb_net_read (fd, tmp, 4); + if (ret == 0) + return ret; + if (ret != 4) + return -1; + l = (tmp[0] << 24) | (tmp[1] << 16) | (tmp[2] << 8) | tmp[3]; + if (l > len) + return -1; + if (krb_net_read (fd, buf, l) != l) + return -1; + status = krb_rd_priv (buf, l, c->schedule, &c->key, + &kc->thataddr, &kc->thisaddr, &msg); + if (status != RD_AP_OK) { + warnx ("krb4_read: %s", krb_get_err_text(status)); + return -1; + } + memmove (buf, msg.app_data, msg.app_length); + return msg.app_length; +} + +/* + * Write a krb4 priv packet on `fd' with the data in `buf, len'. + * Return len or -1 on error + */ + +static ssize_t +krb4_write(kx_context *kc, + int fd, const void *buf, size_t len) +{ + void *outbuf; + krb4_kx_context *c = (krb4_kx_context *)kc->data; + int outlen; + unsigned char tmp[4]; + + outbuf = malloc (len + 30); + if (outbuf == NULL) + return -1; + outlen = krb_mk_priv ((void *)buf, outbuf, len, c->schedule, &c->key, + &kc->thisaddr, &kc->thataddr); + if (outlen < 0) { + free (outbuf); + return -1; + } + tmp[0] = (outlen >> 24) & 0xFF; + tmp[1] = (outlen >> 16) & 0xFF; + tmp[2] = (outlen >> 8) & 0xFF; + tmp[3] = (outlen >> 0) & 0xFF; + + if (krb_net_write (fd, tmp, 4) != 4 || + krb_net_write (fd, outbuf, outlen) != outlen) { + free (outbuf); + return -1; + } + free (outbuf); + return len; +} + +/* + * Copy data from `fd1' to `fd2', {en,de}crypting with cfb64 + * with `mode' and state stored in `iv', `schedule', and `num'. + * Return -1 if error, 0 if eof, else 1 + */ + +static int +do_enccopy (int fd1, int fd2, int mode, des_cblock *iv, + des_key_schedule schedule, int *num) +{ + int ret; + u_char buf[BUFSIZ]; + + ret = read (fd1, buf, sizeof(buf)); + if (ret == 0) + return 0; + if (ret < 0) { + warn ("read"); + return ret; + } +#ifndef NOENCRYPTION + des_cfb64_encrypt (buf, buf, ret, schedule, iv, + num, mode); +#endif + ret = krb_net_write (fd2, buf, ret); + if (ret < 0) { + warn ("write"); + return ret; + } + return 1; +} + +/* + * Copy data between fd1 and fd2, encrypting one way and decrypting + * the other. + */ + +static int +krb4_copy_encrypted (kx_context *kc, + int fd1, int fd2) +{ + krb4_kx_context *c = (krb4_kx_context *)kc->data; + des_cblock iv1, iv2; + int num1 = 0, num2 = 0; + + memcpy (iv1, c->key, sizeof(iv1)); + memcpy (iv2, c->key, sizeof(iv2)); + for (;;) { + fd_set fdset; + int ret; + + if (fd1 >= FD_SETSIZE || fd2 >= FD_SETSIZE) { + warnx ("fd too large"); + return 1; + } + + FD_ZERO(&fdset); + FD_SET(fd1, &fdset); + FD_SET(fd2, &fdset); + + ret = select (max(fd1, fd2)+1, &fdset, NULL, NULL, NULL); + if (ret < 0 && errno != EINTR) { + warn ("select"); + return 1; + } + if (FD_ISSET(fd1, &fdset)) { + ret = do_enccopy (fd1, fd2, DES_ENCRYPT, &iv1, c->schedule, &num1); + if (ret <= 0) + return ret; + } + if (FD_ISSET(fd2, &fdset)) { + ret = do_enccopy (fd2, fd1, DES_DECRYPT, &iv2, c->schedule, &num2); + if (ret <= 0) + return ret; + } + } +} + +/* + * Return 0 if the user authenticated on `kc' is allowed to login as + * `user'. + */ + +static int +krb4_userok (kx_context *kc, char *user) +{ + krb4_kx_context *c = (krb4_kx_context *)kc->data; + char *tmp; + + tmp = krb_unparse_name_long (c->auth.pname, + c->auth.pinst, + c->auth.prealm); + kc->user = strdup (tmp); + if (kc->user == NULL) + err (1, "malloc"); + + + return kuserok (&c->auth, user); +} + +/* + * Create an instance of an krb4 context. + */ + +void +krb4_make_context (kx_context *kc) +{ + kc->authenticate = krb4_authenticate; + kc->userok = krb4_userok; + kc->read = krb4_read; + kc->write = krb4_write; + kc->copy_encrypted = krb4_copy_encrypted; + kc->destroy = krb4_destroy; + kc->user = NULL; + kc->data = malloc(sizeof(krb4_kx_context)); + + if (kc->data == NULL) + err (1, "malloc"); +} + +/* + * Receive authentication information on `sock' (first four bytes + * in `buf'). + */ + +int +recv_v4_auth (kx_context *kc, int sock, u_char *buf) +{ + int status; + KTEXT_ST ticket; + char instance[INST_SZ + 1]; + char version[KRB_SENDAUTH_VLEN + 1]; + krb4_kx_context *c; + AUTH_DAT auth; + des_key_schedule schedule; + + if (memcmp (buf, KRB_SENDAUTH_VERS, 4) != 0) + return -1; + if (net_read (sock, buf + 4, KRB_SENDAUTH_VLEN - 4) != + KRB_SENDAUTH_VLEN - 4) { + syslog (LOG_ERR, "read: %m"); + exit (1); + } + if (memcmp (buf, KRB_SENDAUTH_VERS, KRB_SENDAUTH_VLEN) != 0) { + syslog (LOG_ERR, "unrecognized auth protocol: %.8s", buf); + exit (1); + } + + k_getsockinst (sock, instance, sizeof(instance)); + status = krb_recvauth (KOPT_IGNORE_PROTOCOL | KOPT_DO_MUTUAL, + sock, + &ticket, + "rcmd", + instance, + &kc->thataddr, + &kc->thisaddr, + &auth, + "", + schedule, + version); + if (status != KSUCCESS) { + syslog (LOG_ERR, "krb_recvauth: %s", krb_get_err_text(status)); + exit (1); + } + if (strncmp (version, KX_VERSION, KRB_SENDAUTH_VLEN) != 0) { + /* Try to be nice to old kx's */ + if (strncmp (version, KX_OLD_VERSION, KRB_SENDAUTH_VLEN) == 0) { + char *old_errmsg = "\001Old version of kx. Please upgrade."; + char user[64]; + + syslog (LOG_ERR, "Old version client (%s)", version); + + krb_net_read (sock, user, sizeof(user)); + krb_net_write (sock, old_errmsg, strlen(old_errmsg) + 1); + exit (1); + } else { + syslog (LOG_ERR, "bad version: %s", version); + exit (1); + } + } + + krb4_make_context (kc); + c = (krb4_kx_context *)kc->data; + + c->auth = auth; + memcpy (c->key, &auth.session, sizeof(des_cblock)); + memcpy (c->schedule, schedule, sizeof(schedule)); + + return 0; +} + +#endif /* KRB4 */ |
