diff options
Diffstat (limited to 'source/winbindd/winbindd_cred_cache.c')
| -rw-r--r-- | source/winbindd/winbindd_cred_cache.c | 802 |
1 files changed, 802 insertions, 0 deletions
diff --git a/source/winbindd/winbindd_cred_cache.c b/source/winbindd/winbindd_cred_cache.c new file mode 100644 index 00000000000..65dcbe5a00b --- /dev/null +++ b/source/winbindd/winbindd_cred_cache.c @@ -0,0 +1,802 @@ +/* + Unix SMB/CIFS implementation. + + Winbind daemon - krb5 credential cache functions + and in-memory cache functions. + + Copyright (C) Guenther Deschner 2005-2006 + Copyright (C) Jeremy Allison 2006 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "includes.h" +#include "winbindd.h" +#undef DBGC_CLASS +#define DBGC_CLASS DBGC_WINBIND + +/* uncomment this to do fast debugging on the krb5 ticket renewal event */ +#ifdef DEBUG_KRB5_TKT_RENEWAL +#undef DEBUG_KRB5_TKT_RENEWAL +#endif + +#define MAX_CCACHES 100 + +static struct WINBINDD_CCACHE_ENTRY *ccache_list; + +/* The Krb5 ticket refresh handler should be scheduled + at one-half of the period from now till the tkt + expiration */ +#define KRB5_EVENT_REFRESH_TIME(x) ((x) - (((x) - time(NULL))/2)) + +/**************************************************************** + Find an entry by name. +****************************************************************/ + +static struct WINBINDD_CCACHE_ENTRY *get_ccache_by_username(const char *username) +{ + struct WINBINDD_CCACHE_ENTRY *entry; + + for (entry = ccache_list; entry; entry = entry->next) { + if (strequal(entry->username, username)) { + return entry; + } + } + return NULL; +} + +/**************************************************************** + How many do we have ? +****************************************************************/ + +static int ccache_entry_count(void) +{ + struct WINBINDD_CCACHE_ENTRY *entry; + int i = 0; + + for (entry = ccache_list; entry; entry = entry->next) { + i++; + } + return i; +} + +/**************************************************************** + Do the work of refreshing the ticket. +****************************************************************/ + +static void krb5_ticket_refresh_handler(struct event_context *event_ctx, + struct timed_event *te, + const struct timeval *now, + void *private_data) +{ + struct WINBINDD_CCACHE_ENTRY *entry = + talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY); +#ifdef HAVE_KRB5 + int ret; + time_t new_start; + struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr; +#endif + + DEBUG(10,("krb5_ticket_refresh_handler called\n")); + DEBUGADD(10,("event called for: %s, %s\n", + entry->ccname, entry->username)); + + TALLOC_FREE(entry->event); + +#ifdef HAVE_KRB5 + + /* Kinit again if we have the user password and we can't renew the old + * tgt anymore */ + + if ((entry->renew_until < time(NULL)) && cred_ptr && cred_ptr->pass) { + + set_effective_uid(entry->uid); + + ret = kerberos_kinit_password_ext(entry->principal_name, + cred_ptr->pass, + 0, /* hm, can we do time correction here ? */ + &entry->refresh_time, + &entry->renew_until, + entry->ccname, + False, /* no PAC required anymore */ + True, + WINBINDD_PAM_AUTH_KRB5_RENEW_TIME, + NULL); + gain_root_privilege(); + + if (ret) { + DEBUG(3,("krb5_ticket_refresh_handler: " + "could not re-kinit: %s\n", + error_message(ret))); + TALLOC_FREE(entry->event); + return; + } + + DEBUG(10,("krb5_ticket_refresh_handler: successful re-kinit " + "for: %s in ccache: %s\n", + entry->principal_name, entry->ccname)); + +#if defined(DEBUG_KRB5_TKT_RENEWAL) + new_start = time(NULL) + 30; +#else + /* The tkt should be refreshed at one-half the period + from now to the expiration time */ + new_start = KRB5_EVENT_REFRESH_TIME(entry->refresh_time); +#endif + goto done; + } + + set_effective_uid(entry->uid); + + ret = smb_krb5_renew_ticket(entry->ccname, + entry->principal_name, + entry->service, + &new_start); +#if defined(DEBUG_KRB5_TKT_RENEWAL) + new_start = time(NULL) + 30; +#else + new_start = KRB5_EVENT_REFRESH_TIME(new_start); +#endif + + gain_root_privilege(); + + if (ret) { + DEBUG(3,("krb5_ticket_refresh_handler: " + "could not renew tickets: %s\n", + error_message(ret))); + /* maybe we are beyond the renewing window */ + + /* avoid breaking the renewal chain: retry in + * lp_winbind_cache_time() seconds when the KDC was not + * available right now. */ + + if (ret == KRB5_KDC_UNREACH) { + new_start = time(NULL) + + MAX(30, lp_winbind_cache_time()); + goto done; + } + + return; + } + +done: + + entry->event = event_add_timed(winbind_event_context(), entry, + timeval_set(new_start, 0), + "krb5_ticket_refresh_handler", + krb5_ticket_refresh_handler, + entry); + +#endif +} + +/**************************************************************** + Do the work of regaining a ticket when coming from offline auth. +****************************************************************/ + +static void krb5_ticket_gain_handler(struct event_context *event_ctx, + struct timed_event *te, + const struct timeval *now, + void *private_data) +{ + struct WINBINDD_CCACHE_ENTRY *entry = + talloc_get_type_abort(private_data, struct WINBINDD_CCACHE_ENTRY); +#ifdef HAVE_KRB5 + int ret; + struct timeval t; + struct WINBINDD_MEMORY_CREDS *cred_ptr = entry->cred_ptr; + struct winbindd_domain *domain = NULL; +#endif + + DEBUG(10,("krb5_ticket_gain_handler called\n")); + DEBUGADD(10,("event called for: %s, %s\n", + entry->ccname, entry->username)); + + TALLOC_FREE(entry->event); + +#ifdef HAVE_KRB5 + + if (!cred_ptr || !cred_ptr->pass) { + DEBUG(10,("krb5_ticket_gain_handler: no memory creds\n")); + return; + } + + if ((domain = find_domain_from_name(entry->realm)) == NULL) { + DEBUG(0,("krb5_ticket_gain_handler: unknown domain\n")); + return; + } + + if (!domain->online) { + goto retry_later; + } + + set_effective_uid(entry->uid); + + ret = kerberos_kinit_password_ext(entry->principal_name, + cred_ptr->pass, + 0, /* hm, can we do time correction here ? */ + &entry->refresh_time, + &entry->renew_until, + entry->ccname, + False, /* no PAC required anymore */ + True, + WINBINDD_PAM_AUTH_KRB5_RENEW_TIME, + NULL); + gain_root_privilege(); + + if (ret) { + DEBUG(3,("krb5_ticket_gain_handler: " + "could not kinit: %s\n", + error_message(ret))); + goto retry_later; + } + + DEBUG(10,("krb5_ticket_gain_handler: " + "successful kinit for: %s in ccache: %s\n", + entry->principal_name, entry->ccname)); + + goto got_ticket; + + retry_later: + + t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0); + + entry->event = event_add_timed(winbind_event_context(), + entry, + t, + "krb5_ticket_gain_handler", + krb5_ticket_gain_handler, + entry); + + return; + + got_ticket: + +#if defined(DEBUG_KRB5_TKT_RENEWAL) + t = timeval_set(time(NULL) + 30, 0); +#else + t = timeval_set(KRB5_EVENT_REFRESH_TIME(entry->refresh_time), 0); +#endif + + entry->event = event_add_timed(winbind_event_context(), + entry, + t, + "krb5_ticket_refresh_handler", + krb5_ticket_refresh_handler, + entry); + + return; +#endif +} + +/**************************************************************** + Check if an ccache entry exists. +****************************************************************/ + +BOOL ccache_entry_exists(const char *username) +{ + struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username); + return (entry != NULL); +} + +/**************************************************************** + Ensure we're changing the correct entry. +****************************************************************/ + +BOOL ccache_entry_identical(const char *username, + uid_t uid, + const char *ccname) +{ + struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username); + + if (!entry) { + return False; + } + + if (entry->uid != uid) { + DEBUG(0,("cache_entry_identical: uid's differ: %u != %u\n", + (unsigned int)entry->uid, (unsigned int)uid)); + return False; + } + if (!strcsequal(entry->ccname, ccname)) { + DEBUG(0,("cache_entry_identical: " + "ccnames differ: (cache) %s != (client) %s\n", + entry->ccname, ccname)); + return False; + } + return True; +} + +NTSTATUS add_ccache_to_list(const char *princ_name, + const char *ccname, + const char *service, + const char *username, + const char *realm, + uid_t uid, + time_t create_time, + time_t ticket_end, + time_t renew_until, + BOOL postponed_request) +{ + struct WINBINDD_CCACHE_ENTRY *entry = NULL; + struct timeval t; + + if ((username == NULL && princ_name == NULL) || + ccname == NULL || uid < 0) { + return NT_STATUS_INVALID_PARAMETER; + } + + if (ccache_entry_count() + 1 > MAX_CCACHES) { + DEBUG(10,("add_ccache_to_list: " + "max number of ccaches reached\n")); + return NT_STATUS_NO_MORE_ENTRIES; + } + + /* Reference count old entries */ + entry = get_ccache_by_username(username); + if (entry) { + /* Check cached entries are identical. */ + if (!ccache_entry_identical(username, uid, ccname)) { + return NT_STATUS_INVALID_PARAMETER; + } + entry->ref_count++; + DEBUG(10,("add_ccache_to_list: " + "ref count on entry %s is now %d\n", + username, entry->ref_count)); + /* FIXME: in this case we still might want to have a krb5 cred + * event handler created - gd*/ + return NT_STATUS_OK; + } + + entry = TALLOC_P(NULL, struct WINBINDD_CCACHE_ENTRY); + if (!entry) { + return NT_STATUS_NO_MEMORY; + } + + ZERO_STRUCTP(entry); + + if (username) { + entry->username = talloc_strdup(entry, username); + if (!entry->username) { + goto no_mem; + } + } + if (princ_name) { + entry->principal_name = talloc_strdup(entry, princ_name); + if (!entry->principal_name) { + goto no_mem; + } + } + if (service) { + entry->service = talloc_strdup(entry, service); + if (!entry->service) { + goto no_mem; + } + } + + entry->ccname = talloc_strdup(entry, ccname); + if (!entry->ccname) { + goto no_mem; + } + + entry->realm = talloc_strdup(entry, realm); + if (!entry->realm) { + goto no_mem; + } + + entry->create_time = create_time; + entry->renew_until = renew_until; + entry->uid = uid; + entry->ref_count = 1; + + if (!lp_winbind_refresh_tickets() || renew_until <= 0) { + goto add_entry; + } + + if (postponed_request) { + t = timeval_current_ofs(MAX(30, lp_winbind_cache_time()), 0); + entry->event = event_add_timed(winbind_event_context(), + entry, + t, + "krb5_ticket_gain_handler", + krb5_ticket_gain_handler, + entry); + } else { + /* Renew at 1/2 the ticket expiration time */ +#if defined(DEBUG_KRB5_TKT_RENEWAL) + t = timeval_set(time(NULL)+30, 0); +#else + t = timeval_set(KRB5_EVENT_REFRESH_TIME(ticket_end), 0); +#endif + entry->event = event_add_timed(winbind_event_context(), + entry, + t, + "krb5_ticket_refresh_handler", + krb5_ticket_refresh_handler, + entry); + } + + if (!entry->event) { + goto no_mem; + } + + DEBUG(10,("add_ccache_to_list: added krb5_ticket handler\n")); + + add_entry: + + DLIST_ADD(ccache_list, entry); + + DEBUG(10,("add_ccache_to_list: " + "added ccache [%s] for user [%s] to the list\n", + ccname, username)); + + return NT_STATUS_OK; + + no_mem: + + TALLOC_FREE(entry); + return NT_STATUS_NO_MEMORY; +} + +/******************************************************************* + Remove a WINBINDD_CCACHE_ENTRY entry and the krb5 ccache if no longer + referenced. + *******************************************************************/ + +NTSTATUS remove_ccache(const char *username) +{ + struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username); + NTSTATUS status = NT_STATUS_OK; + #ifdef HAVE_KRB5 + krb5_error_code ret; +#endif + + if (!entry) { + return NT_STATUS_OBJECT_NAME_NOT_FOUND; + } + + if (entry->ref_count <= 0) { + DEBUG(0,("remove_ccache: logic error. " + "ref count for user %s = %d\n", + username, entry->ref_count)); + return NT_STATUS_INTERNAL_DB_CORRUPTION; + } + + entry->ref_count--; + + if (entry->ref_count > 0) { + DEBUG(10,("remove_ccache: entry %s ref count now %d\n", + username, entry->ref_count)); + return NT_STATUS_OK; + } + + /* no references any more */ + + DLIST_REMOVE(ccache_list, entry); + TALLOC_FREE(entry->event); /* unregisters events */ + +#ifdef HAVE_KRB5 + ret = ads_kdestroy(entry->ccname); + + /* we ignore the error when there has been no credential cache */ + if (ret == KRB5_FCC_NOFILE) { + ret = 0; + } else if (ret) { + DEBUG(0,("remove_ccache: " + "failed to destroy user krb5 ccache %s with: %s\n", + entry->ccname, error_message(ret))); + } else { + DEBUG(10,("remove_ccache: " + "successfully destroyed krb5 ccache %s for user %s\n", + entry->ccname, username)); + } + status = krb5_to_nt_status(ret); +#endif + + TALLOC_FREE(entry); + DEBUG(10,("remove_ccache: removed ccache for user %s\n", username)); + + return status; +} + +/******************************************************************* + In memory credentials cache code. +*******************************************************************/ + +static struct WINBINDD_MEMORY_CREDS *memory_creds_list; + +/*********************************************************** + Find an entry on the list by name. +***********************************************************/ + +struct WINBINDD_MEMORY_CREDS *find_memory_creds_by_name(const char *username) +{ + struct WINBINDD_MEMORY_CREDS *p; + + for (p = memory_creds_list; p; p = p->next) { + if (strequal(p->username, username)) { + return p; + } + } + return NULL; +} + +/*********************************************************** + Store the required creds and mlock them. +***********************************************************/ + +static NTSTATUS store_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp, + const char *pass) +{ +#if !defined(HAVE_MLOCK) + return NT_STATUS_OK; +#else + /* new_entry->nt_hash is the base pointer for the block + of memory pointed into by new_entry->lm_hash and + new_entry->pass (if we're storing plaintext). */ + + memcredp->len = NT_HASH_LEN + LM_HASH_LEN; + if (pass) { + memcredp->len += strlen(pass)+1; + } + + +#if defined(LINUX) + /* aligning the memory on on x86_64 and compiling + with gcc 4.1 using -O2 causes a segv in the + next memset() --jerry */ + memcredp->nt_hash = SMB_MALLOC_ARRAY(unsigned char, memcredp->len); +#else + /* On non-linux platforms, mlock()'d memory must be aligned */ + memcredp->nt_hash = SMB_MEMALIGN_ARRAY(unsigned char, + getpagesize(), memcredp->len); +#endif + if (!memcredp->nt_hash) { + return NT_STATUS_NO_MEMORY; + } + memset(memcredp->nt_hash, 0x0, memcredp->len); + + memcredp->lm_hash = memcredp->nt_hash + NT_HASH_LEN; + +#ifdef DEBUG_PASSWORD + DEBUG(10,("mlocking memory: %p\n", memcredp->nt_hash)); +#endif + if ((mlock(memcredp->nt_hash, memcredp->len)) == -1) { + DEBUG(0,("failed to mlock memory: %s (%d)\n", + strerror(errno), errno)); + SAFE_FREE(memcredp->nt_hash); + return map_nt_error_from_unix(errno); + } + +#ifdef DEBUG_PASSWORD + DEBUG(10,("mlocked memory: %p\n", memcredp->nt_hash)); +#endif + + /* Create and store the password hashes. */ + E_md4hash(pass, memcredp->nt_hash); + E_deshash(pass, memcredp->lm_hash); + + if (pass) { + memcredp->pass = (char *)memcredp->lm_hash + LM_HASH_LEN; + memcpy(memcredp->pass, pass, + memcredp->len - NT_HASH_LEN - LM_HASH_LEN); + } + + return NT_STATUS_OK; +#endif +} + +/*********************************************************** + Destroy existing creds. +***********************************************************/ + +static NTSTATUS delete_memory_creds(struct WINBINDD_MEMORY_CREDS *memcredp) +{ +#if !defined(HAVE_MUNLOCK) + return NT_STATUS_OK; +#else + if (munlock(memcredp->nt_hash, memcredp->len) == -1) { + DEBUG(0,("failed to munlock memory: %s (%d)\n", + strerror(errno), errno)); + return map_nt_error_from_unix(errno); + } + memset(memcredp->nt_hash, '\0', memcredp->len); + SAFE_FREE(memcredp->nt_hash); + memcredp->nt_hash = NULL; + memcredp->lm_hash = NULL; + memcredp->pass = NULL; + memcredp->len = 0; + return NT_STATUS_OK; +#endif +} + +/*********************************************************** + Replace the required creds with new ones (password change). +***********************************************************/ + +static NTSTATUS winbindd_replace_memory_creds_internal(struct WINBINDD_MEMORY_CREDS *memcredp, + const char *pass) +{ + NTSTATUS status = delete_memory_creds(memcredp); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + return store_memory_creds(memcredp, pass); +} + +/************************************************************* + Store credentials in memory in a list. +*************************************************************/ + +static NTSTATUS winbindd_add_memory_creds_internal(const char *username, + uid_t uid, + const char *pass) +{ + /* Shortcut to ensure we don't store if no mlock. */ +#if !defined(HAVE_MLOCK) || !defined(HAVE_MUNLOCK) + return NT_STATUS_OK; +#else + NTSTATUS status; + struct WINBINDD_MEMORY_CREDS *memcredp = NULL; + + memcredp = find_memory_creds_by_name(username); + if (uid == (uid_t)-1) { + DEBUG(0,("winbindd_add_memory_creds_internal: " + "invalid uid for user %s.\n", username)); + return NT_STATUS_INVALID_PARAMETER; + } + + if (memcredp) { + /* Already exists. Increment the reference count and replace stored creds. */ + if (uid != memcredp->uid) { + DEBUG(0,("winbindd_add_memory_creds_internal: " + "uid %u for user %s doesn't " + "match stored uid %u. Replacing.\n", + (unsigned int)uid, username, + (unsigned int)memcredp->uid)); + memcredp->uid = uid; + } + memcredp->ref_count++; + DEBUG(10,("winbindd_add_memory_creds_internal: " + "ref count for user %s is now %d\n", + username, memcredp->ref_count)); + return winbindd_replace_memory_creds_internal(memcredp, pass); + } + + memcredp = TALLOC_ZERO_P(NULL, struct WINBINDD_MEMORY_CREDS); + if (!memcredp) { + return NT_STATUS_NO_MEMORY; + } + memcredp->username = talloc_strdup(memcredp, username); + if (!memcredp->username) { + talloc_destroy(memcredp); + return NT_STATUS_NO_MEMORY; + } + + status = store_memory_creds(memcredp, pass); + if (!NT_STATUS_IS_OK(status)) { + talloc_destroy(memcredp); + return status; + } + + memcredp->uid = uid; + memcredp->ref_count = 1; + DLIST_ADD(memory_creds_list, memcredp); + + DEBUG(10,("winbindd_add_memory_creds_internal: " + "added entry for user %s\n", username)); + + return NT_STATUS_OK; +#endif +} + +/************************************************************* + Store users credentials in memory. If we also have a + struct WINBINDD_CCACHE_ENTRY for this username with a + refresh timer, then store the plaintext of the password + and associate the new credentials with the struct WINBINDD_CCACHE_ENTRY. +*************************************************************/ + +NTSTATUS winbindd_add_memory_creds(const char *username, + uid_t uid, + const char *pass) +{ + struct WINBINDD_CCACHE_ENTRY *entry = get_ccache_by_username(username); + NTSTATUS status; + + status = winbindd_add_memory_creds_internal(username, uid, pass); + if (!NT_STATUS_IS_OK(status)) { + return status; + } + + if (entry) { + struct WINBINDD_MEMORY_CREDS *memcredp = NULL; + memcredp = find_memory_creds_by_name(username); + if (memcredp) { + entry->cred_ptr = memcredp; + } + } + + return status; +} + +/************************************************************* + Decrement the in-memory ref count - delete if zero. +*************************************************************/ + +NTSTATUS winbindd_delete_memory_creds(const char *username) +{ + struct WINBINDD_MEMORY_CREDS *memcredp = NULL; + struct WINBINDD_CCACHE_ENTRY *entry = NULL; + NTSTATUS status = NT_STATUS_OK; + + memcredp = find_memory_creds_by_name(username); + entry = get_ccache_by_username(username); + + if (!memcredp) { + DEBUG(10,("winbindd_delete_memory_creds: unknown user %s\n", + username)); + return NT_STATUS_OBJECT_NAME_NOT_FOUND; + } + + if (memcredp->ref_count <= 0) { + DEBUG(0,("winbindd_delete_memory_creds: logic error. " + "ref count for user %s = %d\n", + username, memcredp->ref_count)); + status = NT_STATUS_INTERNAL_DB_CORRUPTION; + } + + memcredp->ref_count--; + if (memcredp->ref_count <= 0) { + delete_memory_creds(memcredp); + DLIST_REMOVE(memory_creds_list, memcredp); + talloc_destroy(memcredp); + DEBUG(10,("winbindd_delete_memory_creds: " + "deleted entry for user %s\n", + username)); + } else { + DEBUG(10,("winbindd_delete_memory_creds: " + "entry for user %s ref_count now %d\n", + username, memcredp->ref_count)); + } + + if (entry) { + /* Ensure we have no dangling references to this. */ + entry->cred_ptr = NULL; + } + + return status; +} + +/*********************************************************** + Replace the required creds with new ones (password change). +***********************************************************/ + +NTSTATUS winbindd_replace_memory_creds(const char *username, + const char *pass) +{ + struct WINBINDD_MEMORY_CREDS *memcredp = NULL; + + memcredp = find_memory_creds_by_name(username); + if (!memcredp) { + DEBUG(10,("winbindd_replace_memory_creds: unknown user %s\n", + username)); + return NT_STATUS_OBJECT_NAME_NOT_FOUND; + } + + DEBUG(10,("winbindd_replace_memory_creds: replaced creds for user %s\n", + username)); + + return winbindd_replace_memory_creds_internal(memcredp, pass); +} |