krb5 commit: Add support to store time offsets in cc_keyring
Greg Hudson
ghudson at MIT.EDU
Fri Nov 15 18:18:42 EST 2013
https://github.com/krb5/krb5/commit/fb4817a32d0c369049e0868468dd2eb75487630d
commit fb4817a32d0c369049e0868468dd2eb75487630d
Author: Simo Sorce <simo at redhat.com>
Date: Thu Nov 14 17:23:59 2013 -0500
Add support to store time offsets in cc_keyring
The code follows the same model used for the memory ccache type. Time
offsets are stored in each credential cache in a special key just like
the principal name. Legacy session caches do not store timestamps as
legacy code would fail when iterating over the new offset key.
[ghudson at mit.edu: minor formatting changes; note legacy session
exception in commit message]
ticket: 7768 (new)
target_version: 1.12
tags: pullup
src/lib/krb5/ccache/cc_keyring.c | 205 +++++++++++++++++++++++++++++++++++++-
1 files changed, 203 insertions(+), 2 deletions(-)
diff --git a/src/lib/krb5/ccache/cc_keyring.c b/src/lib/krb5/ccache/cc_keyring.c
index a07a0dc..2192fa5 100644
--- a/src/lib/krb5/ccache/cc_keyring.c
+++ b/src/lib/krb5/ccache/cc_keyring.c
@@ -189,6 +189,11 @@ debug_print(char *fmt, ...)
#define KRCC_PERSISTENT_KEYRING_NAME "_krb"
/*
+ * Name of the key holding time offsets for the individual cache
+ */
+#define KRCC_TIME_OFFSETS "__krb5_time_offsets__"
+
+/*
* Keyring name prefix and length of random name part
*/
#define KRCC_NAME_PREFIX "krb_ccache_"
@@ -217,6 +222,7 @@ typedef struct _krb5_krcc_cursor
int numkeys;
int currkey;
key_serial_t princ_id;
+ key_serial_t offsets_id;
key_serial_t *keys;
} *krb5_krcc_cursor;
@@ -340,6 +346,12 @@ static krb5_error_code krb5_krcc_save_principal
static krb5_error_code krb5_krcc_retrieve_principal
(krb5_context context, krb5_ccache id, krb5_principal * princ);
+static krb5_error_code krb5_krcc_save_time_offsets
+(krb5_context context, krb5_ccache id, krb5_int32 time_offset,
+ krb5_int32 usec_offset);
+static krb5_error_code krb5_krcc_get_time_offsets
+(krb5_context context, krb5_ccache id, krb5_int32 *time_offset,
+ krb5_int32 *usec_offset);
/* Routines to parse a key from a keyring into a cred structure */
static krb5_error_code krb5_krcc_parse
@@ -410,6 +422,12 @@ krb5_krcc_parse_index(krb5_context context, krb5_int32 *version,
static krb5_error_code
krb5_krcc_unparse_index(krb5_context context, krb5_int32 version,
const char *primary, void **datapp, int *lenptr);
+static krb5_error_code
+krb5_krcc_parse_offsets(krb5_context context, krb5_int32 *time_offset,
+ krb5_int32 *usec_offset, void *payload, int psize);
+static krb5_error_code
+krb5_krcc_unparse_offsets(krb5_context context, krb5_int32 time_offset,
+ krb5_int32 usec_offset, void **datapp, int *lenptr);
/* Note the following is a stub function for Linux */
extern krb5_error_code krb5_change_cache(void);
@@ -835,6 +853,7 @@ krb5_krcc_initialize(krb5_context context, krb5_ccache id,
krb5_principal princ)
{
krb5_krcc_data *data = (krb5_krcc_data *)id->data;
+ krb5_os_context os_ctx = &context->os_context;
krb5_error_code kret;
const char *cache_name, *p;
@@ -863,6 +882,15 @@ krb5_krcc_initialize(krb5_context context, krb5_ccache id,
(void)keyctl_link(data->cache_id, KEY_SPEC_SESSION_KEYRING);
kret = krb5_krcc_save_principal(context, id, princ);
+
+ /* Save time offset if it is valid and this is not a legacy cache. Legacy
+ * applications would fail to parse the new key in the cache keyring. */
+ if (!is_legacy_cache_name(data->name) &&
+ (os_ctx->os_flags & KRB5_OS_TOFFSET_VALID)) {
+ kret = krb5_krcc_save_time_offsets(context, id, os_ctx->time_offset,
+ os_ctx->usec_offset);
+ }
+
if (kret == KRB5_OK)
krb5_change_cache();
@@ -1039,6 +1067,7 @@ make_cache(key_serial_t collection_id, key_serial_t cache_id,
static krb5_error_code KRB5_CALLCONV
krb5_krcc_resolve(krb5_context context, krb5_ccache *id, const char *residual)
{
+ krb5_os_context os_ctx = &context->os_context;
krb5_error_code ret;
key_serial_t collection_id, cache_id;
char *anchor_name = NULL, *collection_name = NULL, *subsidiary_name = NULL;
@@ -1067,6 +1096,19 @@ krb5_krcc_resolve(krb5_context context, krb5_ccache *id, const char *residual)
ret = make_cache(collection_id, cache_id, anchor_name, collection_name,
subsidiary_name, id);
+ if (ret)
+ goto cleanup;
+
+ /* Lookup time offsets if necessary. */
+ if ((context->library_options & KRB5_LIBOPT_SYNC_KDCTIME) &&
+ !(os_ctx->os_flags & KRB5_OS_TOFFSET_VALID)) {
+ if (krb5_krcc_get_time_offsets(context, *id,
+ &os_ctx->time_offset,
+ &os_ctx->usec_offset) == 0) {
+ os_ctx->os_flags &= ~KRB5_OS_TOFFSET_TIME;
+ os_ctx->os_flags |= KRB5_OS_TOFFSET_VALID;
+ }
+ }
cleanup:
free(anchor_name);
@@ -1122,6 +1164,8 @@ krb5_krcc_start_seq_get(krb5_context context, krb5_ccache id,
}
krcursor->princ_id = d->princ_id;
+ krcursor->offsets_id = keyctl_search(d->cache_id, KRCC_KEY_TYPE_USER,
+ KRCC_TIME_OFFSETS, 0);
krcursor->numkeys = size / sizeof(key_serial_t);
krcursor->keys = keys;
@@ -1174,8 +1218,10 @@ krb5_krcc_next_cred(krb5_context context, krb5_ccache id,
if (krcursor->currkey >= krcursor->numkeys)
return KRB5_CC_END;
- /* If we're pointing at the entry with the principal, skip it */
- if (krcursor->keys[krcursor->currkey] == krcursor->princ_id) {
+ /* If we're pointing at the entry with the principal, or at the key
+ * with the time offsets, skip it. */
+ while (krcursor->keys[krcursor->currkey] == krcursor->princ_id ||
+ krcursor->keys[krcursor->currkey] == krcursor->offsets_id) {
krcursor->currkey++;
/* Check if we have now reached the end */
if (krcursor->currkey >= krcursor->numkeys)
@@ -1621,6 +1667,84 @@ errout:
return kret;
}
+static krb5_error_code
+krb5_krcc_save_time_offsets(krb5_context context, krb5_ccache id,
+ krb5_int32 time_offset, krb5_int32 usec_offset)
+{
+ krb5_krcc_data *d = (krb5_krcc_data *)id->data;
+ krb5_error_code kret;
+ key_serial_t newkey;
+ void *payload = NULL;
+ int psize;
+
+ k5_cc_mutex_assert_locked(context, &d->lock);
+
+ /* Prepare the payload. */
+ kret = krb5_krcc_unparse_offsets(context, time_offset, usec_offset,
+ &payload, &psize);
+ CHECK_N_GO(kret, errout);
+
+ /* Add new key into keyring. */
+ newkey = add_key(KRCC_KEY_TYPE_USER, KRCC_TIME_OFFSETS, payload, psize,
+ d->cache_id);
+ if (newkey == -1) {
+ kret = errno;
+ DEBUG_PRINT(("Error adding time offsets key: %s\n", strerror(kret)));
+ } else {
+ kret = KRB5_OK;
+ krb5_krcc_update_change_time(d);
+ }
+
+errout:
+ free(payload);
+ return kret;
+}
+
+static krb5_error_code
+krb5_krcc_get_time_offsets(krb5_context context, krb5_ccache id,
+ krb5_int32 *time_offset, krb5_int32 *usec_offset)
+{
+ krb5_krcc_data *d = (krb5_krcc_data *)id->data;
+ krb5_error_code kret;
+ key_serial_t key;
+ krb5_int32 t, u;
+ void *payload = NULL;
+ int psize;
+
+ k5_cc_mutex_lock(context, &d->lock);
+
+ if (!d->cache_id) {
+ kret = KRB5_FCC_NOFILE;
+ goto errout;
+ }
+
+ key = keyctl_search(d->cache_id, KRCC_KEY_TYPE_USER, KRCC_TIME_OFFSETS, 0);
+ if (key == -1) {
+ kret = ENOENT;
+ goto errout;
+ }
+
+ psize = keyctl_read_alloc(key, &payload);
+ if (psize == -1) {
+ DEBUG_PRINT(("Reading time offsets key %d: %s\n",
+ key, strerror(errno)));
+ kret = KRB5_CC_IO;
+ goto errout;
+ }
+
+ kret = krb5_krcc_parse_offsets(context, &t, &u, payload, psize);
+ if (kret)
+ goto errout;
+
+ *time_offset = t;
+ *usec_offset = u;
+
+errout:
+ free(payload);
+ k5_cc_mutex_unlock(context, &d->lock);
+ return kret;
+}
+
struct krcc_ptcursor_data {
key_serial_t collection_id;
char *anchor_name;
@@ -2656,6 +2780,83 @@ errout:
return kret;
}
+static krb5_error_code
+krb5_krcc_parse_offsets(krb5_context context, krb5_int32 *time_offset,
+ krb5_int32 *usec_offset, void *payload, int psize)
+{
+ krb5_error_code kret;
+ krb5_krcc_bc bc;
+
+ bc.bpp = payload;
+ bc.endp = bc.bpp + psize;
+
+ kret = krb5_krcc_parse_int32(context, time_offset, &bc);
+ CHECK_OUT(kret);
+
+ kret = krb5_krcc_parse_int32(context, usec_offset, &bc);
+ CHECK_OUT(kret);
+
+ return KRB5_OK;
+}
+
+static krb5_error_code
+krb5_krcc_unparse_offsets_internal(krb5_context context,
+ krb5_int32 time_offset,
+ krb5_int32 usec_offset,
+ krb5_krcc_bc *bc)
+{
+ krb5_error_code kret;
+
+ kret = krb5_krcc_unparse_int32(context, time_offset, bc);
+ CHECK_OUT(kret);
+
+ kret = krb5_krcc_unparse_int32(context, usec_offset, bc);
+ CHECK_OUT(kret);
+
+ return KRB5_OK;
+}
+
+static krb5_error_code
+krb5_krcc_unparse_offsets(krb5_context context, krb5_int32 time_offset,
+ krb5_int32 usec_offset, void **datapp, int *lenptr)
+{
+ krb5_error_code kret;
+ krb5_krcc_bc bc;
+ char *buf;
+
+ if (!datapp || !lenptr)
+ return EINVAL;
+
+ *datapp = NULL;
+ *lenptr = 0;
+
+ /* Do a dry run first to calculate the size. */
+ bc.bpp = bc.endp = NULL;
+ bc.size = 0;
+ kret = krb5_krcc_unparse_offsets_internal(context, time_offset,
+ usec_offset, &bc);
+ CHECK_OUT(kret);
+
+ buf = malloc(bc.size);
+ if (buf == NULL)
+ return ENOMEM;
+
+ bc.bpp = buf;
+ bc.endp = buf + bc.size;
+ kret = krb5_krcc_unparse_offsets_internal(context, time_offset,
+ usec_offset, &bc);
+ CHECK(kret);
+
+ /* Success! */
+ *datapp = buf;
+ *lenptr = bc.bpp - buf;
+ kret = KRB5_OK;
+
+errout:
+ if (kret)
+ free(buf);
+ return kret;
+}
/*
* Utility routine: called by krb5_krcc_* functions to keep
* result of krb5_krcc_last_change_time up to date.
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