diff options
Diffstat (limited to 'crypto/heimdal/appl/kx/krb5.c')
| -rw-r--r-- | crypto/heimdal/appl/kx/krb5.c | 421 |
1 files changed, 421 insertions, 0 deletions
diff --git a/crypto/heimdal/appl/kx/krb5.c b/crypto/heimdal/appl/kx/krb5.c new file mode 100644 index 0000000..0b4a083 --- /dev/null +++ b/crypto/heimdal/appl/kx/krb5.c @@ -0,0 +1,421 @@ +/* + * 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: krb5.c,v 1.7 2000/12/31 07:32:03 assar Exp $"); + +#ifdef KRB5 + +struct krb5_kx_context { + krb5_context context; + krb5_keyblock *keyblock; + krb5_crypto crypto; + krb5_principal client; +}; + +typedef struct krb5_kx_context krb5_kx_context; + +/* + * Destroy the krb5 context in `c'. + */ + +static void +krb5_destroy (kx_context *c) +{ + krb5_kx_context *kc = (krb5_kx_context *)c->data; + + if (kc->keyblock) + krb5_free_keyblock (kc->context, kc->keyblock); + if (kc->crypto) + krb5_crypto_destroy (kc->context, kc->crypto); + if (kc->client) + krb5_free_principal (kc->context, kc->client); + if (kc->context) + krb5_free_context (kc->context); + free (kc); +} + +/* + * Read the authentication information from `s' and return 0 if + * succesful, else -1. + */ + +static int +krb5_authenticate (kx_context *kc, int s) +{ + krb5_kx_context *c = (krb5_kx_context *)kc->data; + krb5_context context = c->context; + krb5_auth_context auth_context = NULL; + krb5_error_code ret; + krb5_principal server; + const char *host = kc->host; + + ret = krb5_sname_to_principal (context, + host, "host", KRB5_NT_SRV_HST, &server); + if (ret) { + warnx ("krb5_sname_to_principal: %s: %s", host, + krb5_get_err_text(context, ret)); + return 1; + } + + ret = krb5_sendauth (context, + &auth_context, + &s, + KX_VERSION, + NULL, + server, + AP_OPTS_MUTUAL_REQUIRED, + NULL, + NULL, + NULL, + NULL, + NULL, + NULL); + if (ret) { + warnx ("krb5_sendauth: %s: %s", host, + krb5_get_err_text(context, ret)); + return 1; + } + + ret = krb5_auth_con_getkey (context, auth_context, &c->keyblock); + if (ret) { + warnx ("krb5_auth_con_getkey: %s: %s", host, + krb5_get_err_text(context, ret)); + krb5_auth_con_free (context, auth_context); + return 1; + } + + ret = krb5_crypto_init (context, c->keyblock, 0, &c->crypto); + if (ret) { + warnx ("krb5_crypto_init: %s", krb5_get_err_text (context, ret)); + krb5_auth_con_free (context, auth_context); + return 1; + } + return 0; +} + +/* + * Read an encapsulated krb5 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 +krb5_read (kx_context *kc, + int fd, void *buf, size_t len) +{ + krb5_kx_context *c = (krb5_kx_context *)kc->data; + krb5_context context = c->context; + size_t data_len, outer_len; + krb5_error_code ret; + unsigned char tmp[4]; + krb5_data data; + int l; + + l = krb5_net_read (context, &fd, tmp, 4); + if (l == 0) + return l; + if (l != 4) + return -1; + data_len = (tmp[0] << 24) | (tmp[1] << 16) | (tmp[2] << 8) | tmp[3]; + outer_len = krb5_get_wrapped_length (context, c->crypto, data_len); + if (outer_len > len) + return -1; + if (krb5_net_read (context, &fd, buf, outer_len) != outer_len) + return -1; + + ret = krb5_decrypt (context, c->crypto, KRB5_KU_OTHER_ENCRYPTED, + buf, outer_len, &data); + if (ret) { + warnx ("krb5_decrypt: %s", krb5_get_err_text(context, ret)); + return -1; + } + if (data_len > data.length) { + krb5_data_free (&data); + return -1; + } + memmove (buf, data.data, data_len); + krb5_data_free (&data); + return data_len; +} + +/* + * Write an encapsulated krb5 packet on `fd' with the data in `buf, + * len'. Return len or -1 on error. + */ + +static ssize_t +krb5_write(kx_context *kc, + int fd, const void *buf, size_t len) +{ + krb5_kx_context *c = (krb5_kx_context *)kc->data; + krb5_context context = c->context; + krb5_data data; + krb5_error_code ret; + unsigned char tmp[4]; + size_t outlen; + + ret = krb5_encrypt (context, c->crypto, KRB5_KU_OTHER_ENCRYPTED, + (void *)buf, len, &data); + if (ret){ + warnx ("krb5_write: %s", krb5_get_err_text (context, ret)); + return -1; + } + + outlen = data.length; + tmp[0] = (len >> 24) & 0xFF; + tmp[1] = (len >> 16) & 0xFF; + tmp[2] = (len >> 8) & 0xFF; + tmp[3] = (len >> 0) & 0xFF; + + if (krb5_net_write (context, &fd, tmp, 4) != 4 || + krb5_net_write (context, &fd, data.data, outlen) != outlen) { + krb5_data_free (&data); + return -1; + } + krb5_data_free (&data); + return len; +} + +/* + * Copy from the unix socket `from_fd' encrypting to `to_fd'. + * Return 0, -1 or len. + */ + +static int +copy_out (kx_context *kc, int from_fd, int to_fd) +{ + char buf[32768]; + ssize_t len; + + len = read (from_fd, buf, sizeof(buf)); + if (len == 0) + return 0; + if (len < 0) { + warn ("read"); + return len; + } + return krb5_write (kc, to_fd, buf, len); +} + +/* + * Copy from the socket `from_fd' decrypting to `to_fd'. + * Return 0, -1 or len. + */ + +static int +copy_in (kx_context *kc, int from_fd, int to_fd) +{ + krb5_kx_context *c = (krb5_kx_context *)kc->data; + char buf[33000]; /* XXX */ + + ssize_t len; + + len = krb5_read (kc, from_fd, buf, sizeof(buf)); + if (len == 0) + return 0; + if (len < 0) { + warn ("krb5_read"); + return len; + } + + return krb5_net_write (c->context, &to_fd, buf, len); +} + +/* + * Copy data between `fd1' and `fd2', encrypting in one direction and + * decrypting in the other. + */ + +static int +krb5_copy_encrypted (kx_context *kc, int fd1, int fd2) +{ + 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 = copy_out (kc, fd1, fd2); + if (ret <= 0) + return ret; + } + if (FD_ISSET(fd2, &fdset)) { + ret = copy_in (kc, fd2, fd1); + if (ret <= 0) + return ret; + } + } +} + +/* + * Return 0 if the user authenticated on `kc' is allowed to login as + * `user'. + */ + +static int +krb5_userok (kx_context *kc, char *user) +{ + krb5_kx_context *c = (krb5_kx_context *)kc->data; + krb5_context context = c->context; + krb5_error_code ret; + char *tmp; + + ret = krb5_unparse_name (context, c->client, &tmp); + if (ret) + krb5_err (context, 1, ret, "krb5_unparse_name"); + kc->user = tmp; + + return !krb5_kuserok (context, c->client, user); +} + +/* + * Create an instance of an krb5 context. + */ + +void +krb5_make_context (kx_context *kc) +{ + krb5_kx_context *c; + krb5_error_code ret; + + kc->authenticate = krb5_authenticate; + kc->userok = krb5_userok; + kc->read = krb5_read; + kc->write = krb5_write; + kc->copy_encrypted = krb5_copy_encrypted; + kc->destroy = krb5_destroy; + kc->user = NULL; + kc->data = malloc(sizeof(krb5_kx_context)); + + if (kc->data == NULL) + err (1, "malloc"); + memset (kc->data, 0, sizeof(krb5_kx_context)); + c = (krb5_kx_context *)kc->data; + ret = krb5_init_context (&c->context); + if (ret) + errx (1, "krb5_init_context failed: %d", ret); +} + +/* + * Receive authentication information on `sock' (first four bytes + * in `buf'). + */ + +int +recv_v5_auth (kx_context *kc, int sock, u_char *buf) +{ + u_int32_t len; + krb5_error_code ret; + krb5_kx_context *c; + krb5_context context; + krb5_principal server; + krb5_auth_context auth_context = NULL; + krb5_ticket *ticket; + + if (memcmp (buf, "\x00\x00\x00\x13", 4) != 0) + return 1; + len = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | (buf[3]); + if (net_read(sock, buf, len) != len) { + syslog (LOG_ERR, "read: %m"); + exit (1); + } + if (len != sizeof(KRB5_SENDAUTH_VERSION) + || memcmp (buf, KRB5_SENDAUTH_VERSION, len) != 0) { + syslog (LOG_ERR, "bad sendauth version: %.8s", buf); + exit (1); + } + + krb5_make_context (kc); + c = (krb5_kx_context *)kc->data; + context = c->context; + + ret = krb5_sock_to_principal (context, sock, "host", + KRB5_NT_SRV_HST, &server); + if (ret) { + syslog (LOG_ERR, "krb5_sock_to_principal: %s", + krb5_get_err_text (context, ret)); + exit (1); + } + + ret = krb5_recvauth (context, + &auth_context, + &sock, + KX_VERSION, + server, + KRB5_RECVAUTH_IGNORE_VERSION, + NULL, + &ticket); + krb5_free_principal (context, server); + if (ret) { + syslog (LOG_ERR, "krb5_sock_to_principal: %s", + krb5_get_err_text (context, ret)); + exit (1); + } + + ret = krb5_auth_con_getkey (context, auth_context, &c->keyblock); + if (ret) { + syslog (LOG_ERR, "krb5_auth_con_getkey: %s", + krb5_get_err_text (context, ret)); + exit (1); + } + + ret = krb5_crypto_init (context, c->keyblock, 0, &c->crypto); + if (ret) { + syslog (LOG_ERR, "krb5_crypto_init: %s", + krb5_get_err_text (context, ret)); + exit (1); + } + + c->client = ticket->client; + ticket->client = NULL; + krb5_free_ticket (context, ticket); + + return 0; +} + +#endif /* KRB5 */ |
