diff options
Diffstat (limited to 'crypto/heimdal/kcm/acquire.c')
| -rw-r--r-- | crypto/heimdal/kcm/acquire.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/crypto/heimdal/kcm/acquire.c b/crypto/heimdal/kcm/acquire.c new file mode 100644 index 0000000..416881a --- /dev/null +++ b/crypto/heimdal/kcm/acquire.c @@ -0,0 +1,531 @@ +/* + * Copyright (c) 2005, PADL Software Pty Ltd. + * 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 PADL Software 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 PADL SOFTWARE 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 PADL SOFTWARE 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 "kcm_locl.h" + +RCSID("$Id: acquire.c 22118 2007-12-03 21:44:00Z lha $"); + +static krb5_error_code +change_pw_and_update_keytab(krb5_context context, kcm_ccache ccache); + +/* + * Get a new ticket using a keytab/cached key and swap it into + * an existing redentials cache + */ + +krb5_error_code +kcm_ccache_acquire(krb5_context context, + kcm_ccache ccache, + krb5_creds **credp) +{ + krb5_error_code ret = 0; + krb5_creds cred; + krb5_const_realm realm; + krb5_get_init_creds_opt opt; + krb5_ccache_data ccdata; + char *in_tkt_service = NULL; + int done = 0; + + memset(&cred, 0, sizeof(cred)); + + KCM_ASSERT_VALID(ccache); + + /* We need a cached key or keytab to acquire credentials */ + if (ccache->flags & KCM_FLAGS_USE_CACHED_KEY) { + if (ccache->key.keyblock.keyvalue.length == 0) + krb5_abortx(context, + "kcm_ccache_acquire: KCM_FLAGS_USE_CACHED_KEY without key"); + } else if (ccache->flags & KCM_FLAGS_USE_KEYTAB) { + if (ccache->key.keytab == NULL) + krb5_abortx(context, + "kcm_ccache_acquire: KCM_FLAGS_USE_KEYTAB without keytab"); + } else { + kcm_log(0, "Cannot acquire initial credentials for cache %s without key", + ccache->name); + return KRB5_FCC_INTERNAL; + } + + HEIMDAL_MUTEX_lock(&ccache->mutex); + + /* Fake up an internal ccache */ + kcm_internal_ccache(context, ccache, &ccdata); + + /* Now, actually acquire the creds */ + if (ccache->server != NULL) { + ret = krb5_unparse_name(context, ccache->server, &in_tkt_service); + if (ret) { + kcm_log(0, "Failed to unparse service principal name for cache %s: %s", + ccache->name, krb5_get_err_text(context, ret)); + return ret; + } + } + + realm = krb5_principal_get_realm(context, ccache->client); + + krb5_get_init_creds_opt_init(&opt); + krb5_get_init_creds_opt_set_default_flags(context, "kcm", realm, &opt); + if (ccache->tkt_life != 0) + krb5_get_init_creds_opt_set_tkt_life(&opt, ccache->tkt_life); + if (ccache->renew_life != 0) + krb5_get_init_creds_opt_set_renew_life(&opt, ccache->renew_life); + + if (ccache->flags & KCM_FLAGS_USE_CACHED_KEY) { + ret = krb5_get_init_creds_keyblock(context, + &cred, + ccache->client, + &ccache->key.keyblock, + 0, + in_tkt_service, + &opt); + } else { + /* loosely based on lib/krb5/init_creds_pw.c */ + while (!done) { + ret = krb5_get_init_creds_keytab(context, + &cred, + ccache->client, + ccache->key.keytab, + 0, + in_tkt_service, + &opt); + switch (ret) { + case KRB5KDC_ERR_KEY_EXPIRED: + if (in_tkt_service != NULL && + strcmp(in_tkt_service, "kadmin/changepw") == 0) { + goto out; + } + + ret = change_pw_and_update_keytab(context, ccache); + if (ret) + goto out; + break; + case 0: + default: + done = 1; + break; + } + } + } + + if (ret) { + kcm_log(0, "Failed to acquire credentials for cache %s: %s", + ccache->name, krb5_get_err_text(context, ret)); + if (in_tkt_service != NULL) + free(in_tkt_service); + goto out; + } + + if (in_tkt_service != NULL) + free(in_tkt_service); + + /* Swap them in */ + kcm_ccache_remove_creds_internal(context, ccache); + + ret = kcm_ccache_store_cred_internal(context, ccache, &cred, 0, credp); + if (ret) { + kcm_log(0, "Failed to store credentials for cache %s: %s", + ccache->name, krb5_get_err_text(context, ret)); + krb5_free_cred_contents(context, &cred); + goto out; + } + +out: + HEIMDAL_MUTEX_unlock(&ccache->mutex); + + return ret; +} + +static krb5_error_code +change_pw(krb5_context context, + kcm_ccache ccache, + char *cpn, + char *newpw) +{ + krb5_error_code ret; + krb5_creds cpw_cred; + int result_code; + krb5_data result_code_string; + krb5_data result_string; + krb5_get_init_creds_opt options; + + memset(&cpw_cred, 0, sizeof(cpw_cred)); + + krb5_get_init_creds_opt_init(&options); + krb5_get_init_creds_opt_set_tkt_life(&options, 60); + krb5_get_init_creds_opt_set_forwardable(&options, FALSE); + krb5_get_init_creds_opt_set_proxiable(&options, FALSE); + + krb5_data_zero(&result_code_string); + krb5_data_zero(&result_string); + + ret = krb5_get_init_creds_keytab(context, + &cpw_cred, + ccache->client, + ccache->key.keytab, + 0, + "kadmin/changepw", + &options); + if (ret) { + kcm_log(0, "Failed to acquire password change credentials " + "for principal %s: %s", + cpn, krb5_get_err_text(context, ret)); + goto out; + } + + ret = krb5_set_password(context, + &cpw_cred, + newpw, + ccache->client, + &result_code, + &result_code_string, + &result_string); + if (ret) { + kcm_log(0, "Failed to change password for principal %s: %s", + cpn, krb5_get_err_text(context, ret)); + goto out; + } + + if (result_code) { + kcm_log(0, "Failed to change password for principal %s: %.*s", + cpn, + (int)result_string.length, + result_string.length > 0 ? (char *)result_string.data : ""); + goto out; + } + +out: + krb5_data_free(&result_string); + krb5_data_free(&result_code_string); + krb5_free_cred_contents(context, &cpw_cred); + + return ret; +} + +struct kcm_keyseed_data { + krb5_salt salt; + const char *password; +}; + +static krb5_error_code +kcm_password_key_proc(krb5_context context, + krb5_enctype etype, + krb5_salt salt, + krb5_const_pointer keyseed, + krb5_keyblock **key) +{ + krb5_error_code ret; + struct kcm_keyseed_data *s = (struct kcm_keyseed_data *)keyseed; + + /* we may be called multiple times */ + krb5_free_salt(context, s->salt); + krb5_data_zero(&s->salt.saltvalue); + + /* stash the salt */ + s->salt.salttype = salt.salttype; + + ret = krb5_data_copy(&s->salt.saltvalue, + salt.saltvalue.data, + salt.saltvalue.length); + if (ret) + return ret; + + *key = (krb5_keyblock *)malloc(sizeof(**key)); + if (*key == NULL) { + return ENOMEM; + } + + ret = krb5_string_to_key_salt(context, etype, s->password, + s->salt, *key); + if (ret) { + free(*key); + *key = NULL; + } + + return ret; +} + +static krb5_error_code +get_salt_and_kvno(krb5_context context, + kcm_ccache ccache, + krb5_enctype *etypes, + char *cpn, + char *newpw, + krb5_salt *salt, + unsigned *kvno) +{ + krb5_error_code ret; + krb5_creds creds; + krb5_ccache_data ccdata; + krb5_flags options = 0; + krb5_kdc_rep reply; + struct kcm_keyseed_data s; + + memset(&creds, 0, sizeof(creds)); + memset(&reply, 0, sizeof(reply)); + + s.password = NULL; + s.salt.salttype = (int)ETYPE_NULL; + krb5_data_zero(&s.salt.saltvalue); + + *kvno = 0; + kcm_internal_ccache(context, ccache, &ccdata); + s.password = newpw; + + /* Do an AS-REQ to determine salt and key version number */ + ret = krb5_copy_principal(context, ccache->client, &creds.client); + if (ret) + return ret; + + /* Yes, get a ticket to ourselves */ + ret = krb5_copy_principal(context, ccache->client, &creds.server); + if (ret) { + krb5_free_principal(context, creds.client); + return ret; + } + + ret = krb5_get_in_tkt(context, + options, + NULL, + etypes, + NULL, + kcm_password_key_proc, + &s, + NULL, + NULL, + &creds, + &ccdata, + &reply); + if (ret) { + kcm_log(0, "Failed to get self ticket for principal %s: %s", + cpn, krb5_get_err_text(context, ret)); + krb5_free_salt(context, s.salt); + } else { + *salt = s.salt; /* retrieve stashed salt */ + if (reply.kdc_rep.enc_part.kvno != NULL) + *kvno = *(reply.kdc_rep.enc_part.kvno); + } + /* ccache may have been modified but it will get trashed anyway */ + + krb5_free_cred_contents(context, &creds); + krb5_free_kdc_rep(context, &reply); + + return ret; +} + +static krb5_error_code +update_keytab_entry(krb5_context context, + kcm_ccache ccache, + krb5_enctype etype, + char *cpn, + char *spn, + char *newpw, + krb5_salt salt, + unsigned kvno) +{ + krb5_error_code ret; + krb5_keytab_entry entry; + krb5_data pw; + + memset(&entry, 0, sizeof(entry)); + + pw.data = (char *)newpw; + pw.length = strlen(newpw); + + ret = krb5_string_to_key_data_salt(context, etype, pw, + salt, &entry.keyblock); + if (ret) { + kcm_log(0, "String to key conversion failed for principal %s " + "and etype %d: %s", + cpn, etype, krb5_get_err_text(context, ret)); + return ret; + } + + if (spn == NULL) { + ret = krb5_copy_principal(context, ccache->client, + &entry.principal); + if (ret) { + kcm_log(0, "Failed to copy principal name %s: %s", + cpn, krb5_get_err_text(context, ret)); + return ret; + } + } else { + ret = krb5_parse_name(context, spn, &entry.principal); + if (ret) { + kcm_log(0, "Failed to parse SPN alias %s: %s", + spn, krb5_get_err_text(context, ret)); + return ret; + } + } + + entry.vno = kvno; + entry.timestamp = time(NULL); + + ret = krb5_kt_add_entry(context, ccache->key.keytab, &entry); + if (ret) { + kcm_log(0, "Failed to update keytab for principal %s " + "and etype %d: %s", + cpn, etype, krb5_get_err_text(context, ret)); + } + + krb5_kt_free_entry(context, &entry); + + return ret; +} + +static krb5_error_code +update_keytab_entries(krb5_context context, + kcm_ccache ccache, + krb5_enctype *etypes, + char *cpn, + char *spn, + char *newpw, + krb5_salt salt, + unsigned kvno) +{ + krb5_error_code ret = 0; + int i; + + for (i = 0; etypes[i] != ETYPE_NULL; i++) { + ret = update_keytab_entry(context, ccache, etypes[i], + cpn, spn, newpw, salt, kvno); + if (ret) + break; + } + + return ret; +} + +static void +generate_random_pw(krb5_context context, + char *buf, + size_t bufsiz) +{ + unsigned char x[512], *p; + size_t i; + + memset(x, 0, sizeof(x)); + krb5_generate_random_block(x, sizeof(x)); + p = x; + + for (i = 0; i < bufsiz; i++) { + while (isprint(*p) == 0) + p++; + + if (p - x >= sizeof(x)) { + krb5_generate_random_block(x, sizeof(x)); + p = x; + } + buf[i] = (char)*p++; + } + buf[bufsiz - 1] = '\0'; + memset(x, 0, sizeof(x)); +} + +static krb5_error_code +change_pw_and_update_keytab(krb5_context context, + kcm_ccache ccache) +{ + char newpw[121]; + krb5_error_code ret; + unsigned kvno; + krb5_salt salt; + krb5_enctype *etypes = NULL; + int i; + char *cpn = NULL; + char **spns = NULL; + + krb5_data_zero(&salt.saltvalue); + + ret = krb5_unparse_name(context, ccache->client, &cpn); + if (ret) { + kcm_log(0, "Failed to unparse name: %s", + krb5_get_err_text(context, ret)); + goto out; + } + + ret = krb5_get_default_in_tkt_etypes(context, &etypes); + if (ret) { + kcm_log(0, "Failed to determine default encryption types: %s", + krb5_get_err_text(context, ret)); + goto out; + } + + /* Generate a random password (there is no set keys protocol) */ + generate_random_pw(context, newpw, sizeof(newpw)); + + /* Change it */ + ret = change_pw(context, ccache, cpn, newpw); + if (ret) + goto out; + + /* Do an AS-REQ to determine salt and key version number */ + ret = get_salt_and_kvno(context, ccache, etypes, cpn, newpw, + &salt, &kvno); + if (ret) { + kcm_log(0, "Failed to determine salting principal for principal %s: %s", + cpn, krb5_get_err_text(context, ret)); + goto out; + } + + /* Add canonical name */ + ret = update_keytab_entries(context, ccache, etypes, cpn, + NULL, newpw, salt, kvno); + if (ret) + goto out; + + /* Add SPN aliases, if any */ + spns = krb5_config_get_strings(context, NULL, "kcm", + "system_ccache", "spn_aliases", NULL); + if (spns != NULL) { + for (i = 0; spns[i] != NULL; i++) { + ret = update_keytab_entries(context, ccache, etypes, cpn, + spns[i], newpw, salt, kvno); + if (ret) + goto out; + } + } + + kcm_log(0, "Changed expired password for principal %s in cache %s", + cpn, ccache->name); + +out: + if (cpn != NULL) + free(cpn); + if (spns != NULL) + krb5_config_free_strings(spns); + if (etypes != NULL) + free(etypes); + krb5_free_salt(context, salt); + memset(newpw, 0, sizeof(newpw)); + + return ret; +} + |
