krb5_error_code
kcm_access(krb5_context context,
kcm_client *client,
kcm_operation opcode,
kcm_ccache ccache)
{
int read_p = 0;
int write_p = 0;
uint16_t mask;
krb5_error_code ret;
KCM_ASSERT_VALID(ccache);
switch (opcode) {
case KCM_OP_INITIALIZE:
case KCM_OP_DESTROY:
case KCM_OP_STORE:
case KCM_OP_REMOVE_CRED:
case KCM_OP_SET_FLAGS:
case KCM_OP_CHOWN:
case KCM_OP_CHMOD:
case KCM_OP_GET_INITIAL_TICKET:
case KCM_OP_GET_TICKET:
case KCM_OP_MOVE_CACHE:
case KCM_OP_SET_DEFAULT_CACHE:
case KCM_OP_SET_KDC_OFFSET:
write_p = 1;
read_p = 0;
break;
case KCM_OP_NOOP:
case KCM_OP_GET_NAME:
case KCM_OP_RESOLVE:
case KCM_OP_GEN_NEW:
case KCM_OP_RETRIEVE:
case KCM_OP_GET_PRINCIPAL:
case KCM_OP_GET_CRED_UUID_LIST:
case KCM_OP_GET_CRED_BY_UUID:
case KCM_OP_GET_CACHE_UUID_LIST:
case KCM_OP_GET_CACHE_BY_UUID:
case KCM_OP_GET_DEFAULT_CACHE:
case KCM_OP_GET_KDC_OFFSET:
write_p = 0;
read_p = 1;
break;
default:
ret = KRB5_FCC_PERM;
goto out;
}
if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM) {
/* System caches cannot be reinitialized or destroyed by users */
if (opcode == KCM_OP_INITIALIZE ||
opcode == KCM_OP_DESTROY ||
opcode == KCM_OP_REMOVE_CRED ||
opcode == KCM_OP_MOVE_CACHE) {
ret = KRB5_FCC_PERM;
goto out;
}
/* Let root always read system caches */
if (CLIENT_IS_ROOT(client)) {
ret = 0;
goto out;
}
}
/* start out with "other" mask */
mask = S_IROTH|S_IWOTH;
/* root can do anything */
if (CLIENT_IS_ROOT(client)) {
if (read_p)
mask |= S_IRUSR|S_IRGRP|S_IROTH;
if (write_p)
mask |= S_IWUSR|S_IWGRP|S_IWOTH;
}
/* same session same as owner */
if (kcm_is_same_session(client, ccache->uid, ccache->session)) {
if (read_p)
mask |= S_IROTH;
if (write_p)
mask |= S_IWOTH;
}
/* owner */
if (client->uid == ccache->uid) {
if (read_p)
mask |= S_IRUSR;
if (write_p)
mask |= S_IWUSR;
}
/* group */
if (client->gid == ccache->gid) {
if (read_p)
mask |= S_IRGRP;
if (write_p)
mask |= S_IWGRP;
}
ret = (ccache->mode & mask) ? 0 : KRB5_FCC_PERM;
out:
if (ret) {
kcm_log(2, "Process %d is not permitted to call %s on cache %s",
client->pid, kcm_op2string(opcode), ccache->name);
}
return ret;
}
krb5_error_code
kcm_dispatch(krb5_context context,
kcm_client *client,
krb5_data *req_data,
krb5_data *resp_data)
{
krb5_error_code ret;
kcm_method method;
krb5_storage *req_sp = NULL;
krb5_storage *resp_sp = NULL;
uint16_t opcode;
resp_sp = krb5_storage_emem();
if (resp_sp == NULL) {
return ENOMEM;
}
if (client->pid == -1) {
kcm_log(0, "Client had invalid process number");
ret = KRB5_FCC_INTERNAL;
goto out;
}
req_sp = krb5_storage_from_data(req_data);
if (req_sp == NULL) {
kcm_log(0, "Process %d: failed to initialize storage from data",
client->pid);
ret = KRB5_CC_IO;
goto out;
}
ret = krb5_ret_uint16(req_sp, &opcode);
if (ret) {
kcm_log(0, "Process %d: didn't send a message", client->pid);
goto out;
}
if (opcode >= sizeof(kcm_ops)/sizeof(kcm_ops[0])) {
kcm_log(0, "Process %d: invalid operation code %d",
client->pid, opcode);
ret = KRB5_FCC_INTERNAL;
goto out;
}
method = kcm_ops[opcode].method;
if (method == NULL) {
kcm_log(0, "Process %d: operation code %s not implemented",
client->pid, kcm_op2string(opcode));
ret = KRB5_FCC_INTERNAL;
goto out;
}
/* seek past place for status code */
krb5_storage_seek(resp_sp, 4, SEEK_SET);
ret = (*method)(context, client, opcode, req_sp, resp_sp);
out:
if (req_sp != NULL) {
krb5_storage_free(req_sp);
}
krb5_storage_seek(resp_sp, 0, SEEK_SET);
krb5_store_int32(resp_sp, ret);
ret = krb5_storage_to_data(resp_sp, resp_data);
krb5_storage_free(resp_sp);
return ret;
}
krb5_error_code
kcm_access(krb5_context context,
kcm_client *client,
kcm_operation opcode,
kcm_ccache ccache)
{
int read_p = 0;
int write_p = 0;
uint16_t mask;
krb5_error_code ret;
KCM_ASSERT_VALID(ccache);
switch (opcode) {
case KCM_OP_INITIALIZE:
case KCM_OP_DESTROY:
case KCM_OP_STORE:
case KCM_OP_REMOVE_CRED:
case KCM_OP_SET_FLAGS:
case KCM_OP_CHOWN:
case KCM_OP_CHMOD:
case KCM_OP_GET_INITIAL_TICKET:
case KCM_OP_GET_TICKET:
write_p = 1;
read_p = 0;
break;
case KCM_OP_NOOP:
case KCM_OP_GET_NAME:
case KCM_OP_RESOLVE:
case KCM_OP_GEN_NEW:
case KCM_OP_RETRIEVE:
case KCM_OP_GET_PRINCIPAL:
case KCM_OP_GET_FIRST:
case KCM_OP_GET_NEXT:
case KCM_OP_END_GET:
case KCM_OP_MAX:
write_p = 0;
read_p = 1;
break;
}
if (ccache->flags & KCM_FLAGS_OWNER_IS_SYSTEM) {
/* System caches cannot be reinitialized or destroyed by users */
if (opcode == KCM_OP_INITIALIZE ||
opcode == KCM_OP_DESTROY ||
opcode == KCM_OP_REMOVE_CRED) {
ret = KRB5_FCC_PERM;
goto out;
}
/* Let root always read system caches */
if (client->uid == 0) {
ret = 0;
goto out;
}
}
mask = 0;
/* Root may do whatever they like */
if (client->uid == ccache->uid || CLIENT_IS_ROOT(client)) {
if (read_p)
mask |= S_IRUSR;
if (write_p)
mask |= S_IWUSR;
} else if (client->gid == ccache->gid || CLIENT_IS_ROOT(client)) {
if (read_p)
mask |= S_IRGRP;
if (write_p)
mask |= S_IWGRP;
} else {
if (read_p)
mask |= S_IROTH;
if (write_p)
mask |= S_IWOTH;
}
ret = ((ccache->mode & mask) == mask) ? 0 : KRB5_FCC_PERM;
out:
if (ret) {
kcm_log(2, "Process %d is not permitted to call %s on cache %s",
client->pid, kcm_op2string(opcode), ccache->name);
}
return ret;
}
