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/*
* http_auth - HTTP authentication and authorization
*
* Largely-rewritten from original
* Copyright(c) 2016,2021 Glenn Strauss gstrauss()gluelogic.com All rights reserved
* License: BSD 3-clause (same as lighttpd)
*/
#include "first.h"
#include <stdlib.h>
#include <string.h>
#include "mod_auth_api.h"
#include "sys-crypto-md.h" /* USE_LIB_CRYPTO */
#include "base.h"
#include "ck.h"
#include "http_header.h"
#include "log.h"
#include "algo_splaytree.h"
#include "plugin.h"
#include "plugin_config.h"
/**
* auth framework
*/
typedef struct {
splay_tree *sptree; /* data in nodes of tree are (http_auth_cache_entry *)*/
time_t max_age;
} http_auth_cache;
typedef struct {
const http_auth_backend_t *auth_backend;
const array *auth_require;
http_auth_cache *auth_cache;
unsigned int auth_extern_authn;
} plugin_config;
typedef struct {
PLUGIN_DATA;
plugin_config defaults;
plugin_config conf;
} plugin_data;
typedef struct {
const struct http_auth_require_t *require;
unix_time64_t ctime;
int dalgo;
uint32_t dlen;
uint32_t ulen;
char *username;
char *pwdigest;
} http_auth_cache_entry;
static http_auth_cache_entry *
http_auth_cache_entry_init (const struct http_auth_require_t * const require, const int dalgo, const char *username, const uint32_t ulen, const char *pw, const uint32_t pwlen)
{
/*(similar to buffer_copy_string_len() for each element,
* but allocate exact lengths in single chunk of memory
* for cache to avoid wasting space and for memory locality)*/
/* http_auth_require_t is stored instead of copying realm
*(store pointer to http_auth_require_t, which is persistent
* and will be different for each realm + permissions combo)*/
http_auth_cache_entry * const ae =
malloc(sizeof(http_auth_cache_entry) + ulen + pwlen+1);
force_assert(ae);
ae->require = require;
ae->ctime = log_monotonic_secs;
ae->dalgo = dalgo;
ae->ulen = ulen;
ae->dlen = pwlen;
ae->username = (char *)(ae + 1);
ae->pwdigest = ae->username + ulen;
memcpy(ae->username, username, ulen);
memcpy(ae->pwdigest, pw, pwlen);
ae->pwdigest[pwlen] = '\0';
return ae;
}
static void
http_auth_cache_entry_free (void *data)
{
http_auth_cache_entry * const ae = data;
ck_memzero(ae->pwdigest, ae->dlen);
free(ae);
}
static void
http_auth_cache_free (http_auth_cache *ac)
{
splay_tree *sptree = ac->sptree;
while (sptree) {
http_auth_cache_entry_free(sptree->data);
sptree = splaytree_delete(sptree, sptree->key);
}
free(ac);
}
static http_auth_cache *
http_auth_cache_init (const array *opts)
{
http_auth_cache *ac = malloc(sizeof(http_auth_cache));
force_assert(ac);
ac->sptree = NULL;
ac->max_age = 600; /* 10 mins */
for (uint32_t i = 0, used = opts->used; i < used; ++i) {
data_unset *du = opts->data[i];
if (buffer_is_equal_string(&du->key, CONST_STR_LEN("max-age")))
ac->max_age = (time_t)config_plugin_value_to_int32(du, ac->max_age);
}
return ac;
}
static int
http_auth_cache_hash (const struct http_auth_require_t * const require, const char *username, const uint32_t ulen)
{
uint32_t h = /*(hash pointer value, which includes realm and permissions)*/
djbhash((char *)(intptr_t)require, sizeof(intptr_t), DJBHASH_INIT);
h = djbhash(username, ulen, h);
/* strip highest bit of hash value for splaytree (see splaytree_djbhash())*/
return (int32_t)(h & ~(((uint32_t)1) << 31));
}
static http_auth_cache_entry *
http_auth_cache_query (splay_tree ** const sptree, const int ndx)
{
*sptree = splaytree_splay(*sptree, ndx);
return (*sptree && (*sptree)->key == ndx) ? (*sptree)->data : NULL;
}
static void
http_auth_cache_insert (splay_tree ** const sptree, const int ndx, void * const data, void(data_free_fn)(void *))
{
/*(not necessary to re-splay (with current usage) since single-threaded
* and splaytree has not been modified since http_auth_cache_query())*/
/* *sptree = splaytree_splay(*sptree, ndx); */
if (NULL == *sptree || (*sptree)->key != ndx)
*sptree = splaytree_insert(*sptree, ndx, data);
else { /* collision; replace old entry */
data_free_fn((*sptree)->data);
(*sptree)->data = data;
}
}
/* walk though cache, collect expired ids, and remove them in a second loop */
static void
mod_auth_tag_old_entries (splay_tree * const t, int * const keys, int * const ndx, const time_t max_age, const unix_time64_t cur_ts)
{
if (*ndx == 8192) return; /*(must match num array entries in keys[])*/
if (t->left)
mod_auth_tag_old_entries(t->left, keys, ndx, max_age, cur_ts);
if (t->right)
mod_auth_tag_old_entries(t->right, keys, ndx, max_age, cur_ts);
if (*ndx == 8192) return; /*(must match num array entries in keys[])*/
const http_auth_cache_entry * const ae = t->data;
if (cur_ts - ae->ctime > max_age)
keys[(*ndx)++] = t->key;
}
__attribute_noinline__
static void
mod_auth_periodic_cleanup(splay_tree **sptree_ptr, const time_t max_age, const unix_time64_t cur_ts)
{
splay_tree *sptree = *sptree_ptr;
int max_ndx, i;
int keys[8192]; /* 32k size on stack */
do {
if (!sptree) break;
max_ndx = 0;
mod_auth_tag_old_entries(sptree, keys, &max_ndx, max_age, cur_ts);
for (i = 0; i < max_ndx; ++i) {
int ndx = keys[i];
sptree = splaytree_splay(sptree, ndx);
if (sptree && sptree->key == ndx) {
http_auth_cache_entry_free(sptree->data);
sptree = splaytree_delete(sptree, ndx);
}
}
} while (max_ndx == sizeof(keys)/sizeof(int));
*sptree_ptr = sptree;
}
TRIGGER_FUNC(mod_auth_periodic)
{
const plugin_data * const p = p_d;
const unix_time64_t cur_ts = log_monotonic_secs;
if (cur_ts & 0x7) return HANDLER_GO_ON; /*(continue once each 8 sec)*/
UNUSED(srv);
/* future: might construct array of (http_auth_cache *) at startup
* to avoid the need to search for them here */
/* (init i to 0 if global context; to 1 to skip empty global context) */
if (NULL == p->cvlist) return HANDLER_GO_ON;
for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) {
const config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
for (; cpv->k_id != -1; ++cpv) {
if (cpv->k_id != 3) continue; /* k_id == 3 for auth.cache */
if (cpv->vtype != T_CONFIG_LOCAL) continue;
http_auth_cache *ac = cpv->v.v;
mod_auth_periodic_cleanup(&ac->sptree, ac->max_age, cur_ts);
}
}
return HANDLER_GO_ON;
}
static handler_t mod_auth_check_basic(request_st *r, void *p_d, const struct http_auth_require_t *require, const struct http_auth_backend_t *backend);
static handler_t mod_auth_check_digest(request_st *r, void *p_d, const struct http_auth_require_t *require, const struct http_auth_backend_t *backend);
static handler_t mod_auth_check_extern(request_st *r, void *p_d, const struct http_auth_require_t *require, const struct http_auth_backend_t *backend);
INIT_FUNC(mod_auth_init) {
static http_auth_scheme_t http_auth_scheme_basic = { "basic", mod_auth_check_basic, NULL };
static http_auth_scheme_t http_auth_scheme_digest = { "digest", mod_auth_check_digest, NULL };
static const http_auth_scheme_t http_auth_scheme_extern = { "extern", mod_auth_check_extern, NULL };
plugin_data *p = calloc(1, sizeof(*p));
force_assert(p);
/* register http_auth_scheme_* */
http_auth_scheme_basic.p_d = p;
http_auth_scheme_set(&http_auth_scheme_basic);
http_auth_scheme_digest.p_d = p;
http_auth_scheme_set(&http_auth_scheme_digest);
http_auth_scheme_set(&http_auth_scheme_extern);
return p;
}
FREE_FUNC(mod_auth_free) {
plugin_data * const p = p_d;
if (NULL == p->cvlist) return;
/* (init i to 0 if global context; to 1 to skip empty global context) */
for (int i = !p->cvlist[0].v.u2[1], used = p->nconfig; i < used; ++i) {
config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
for (; -1 != cpv->k_id; ++cpv) {
if (cpv->vtype != T_CONFIG_LOCAL || NULL == cpv->v.v) continue;
switch (cpv->k_id) {
case 1: /* auth.require */
array_free(cpv->v.v);
break;
case 3: /* auth.cache */
http_auth_cache_free(cpv->v.v);
break;
default:
break;
}
}
}
http_auth_dumbdata_reset();
}
/* data type for mod_auth structured data
* (parsed from auth.require array of strings) */
typedef struct {
DATA_UNSET;
http_auth_require_t *require;
} data_auth;
static void data_auth_free(data_unset *d)
{
data_auth * const dauth = (data_auth *)d;
free(dauth->key.ptr);
http_auth_require_free(dauth->require);
free(dauth);
}
static data_auth *data_auth_init(void)
{
static const struct data_methods fn = {
NULL, /* copy must not be called on this data */
data_auth_free,
NULL, /* insert_dup must not be called on this data */
};
data_auth * const dauth = calloc(1, sizeof(*dauth));
force_assert(NULL != dauth);
dauth->type = TYPE_OTHER;
dauth->fn = &fn;
dauth->require = http_auth_require_init();
return dauth;
}
static int mod_auth_algorithm_parse(http_auth_info_t *ai, const char *s, size_t len) {
if (0 == len) {
ai->dalgo = HTTP_AUTH_DIGEST_MD5;
ai->dlen = HTTP_AUTH_DIGEST_MD5_BINLEN;
return 1;
}
if (len > 5
&& (s[len-5] ) == '-'
&& (s[len-4] | 0x20) == 's'
&& (s[len-3] | 0x20) == 'e'
&& (s[len-2] | 0x20) == 's'
&& (s[len-1] | 0x20) == 's') {
ai->dalgo = HTTP_AUTH_DIGEST_SESS;
len -= 5;
}
else {
ai->dalgo = HTTP_AUTH_DIGEST_NONE;
}
if (3 == len
&& 'm' == (s[0] | 0x20)
&& 'd' == (s[1] | 0x20)
&& '5' == (s[2] )) {
ai->dalgo |= HTTP_AUTH_DIGEST_MD5;
ai->dlen = HTTP_AUTH_DIGEST_MD5_BINLEN;
return 1;
}
#ifdef USE_LIB_CRYPTO
else if (len >= 7
&& 's' == (s[0] | 0x20)
&& 'h' == (s[1] | 0x20)
&& 'a' == (s[2] | 0x20)
&& '-' == (s[3] )) {
if (len == 7 && s[4] == '2' && s[5] == '5' && s[6] == '6') {
ai->dalgo |= HTTP_AUTH_DIGEST_SHA256;
ai->dlen = HTTP_AUTH_DIGEST_SHA256_BINLEN;
return 1;
}
#ifdef USE_LIB_CRYPTO_SHA512_256
if (len == 11 && 0 == memcmp(s+4, "512-256", 7)) {
ai->dalgo |= HTTP_AUTH_DIGEST_SHA512_256;
ai->dlen = HTTP_AUTH_DIGEST_SHA512_256_BINLEN;
return 1;
}
#endif
}
#endif
return 0; /*(error)*/
}
static int mod_auth_algorithms_parse(int *algorithm, buffer *algos) {
for (const char *s = algos->ptr, *p; s; s = p ? p+1 : NULL) {
http_auth_info_t ai;
p = strchr(s, '|');
if (!mod_auth_algorithm_parse(&ai, s, p ? (size_t)(p - s) : strlen(s)))
return 0;
*algorithm |= ai.dalgo;
}
return 1;
}
static int mod_auth_require_parse (http_auth_require_t * const require, const buffer *b, log_error_st *errh)
{
/* user=name1|user=name2|group=name3|host=name4 */
const char *str = b->ptr;
const char *p;
if (buffer_is_equal_string(b, CONST_STR_LEN("valid-user"))) {
require->valid_user = 1;
return 1; /* success */
}
do {
const char *eq;
size_t len;
p = strchr(str, '|');
len = NULL != p ? (size_t)(p - str) : strlen(str);
eq = memchr(str, '=', len);
if (NULL == eq) {
log_error(errh, __FILE__, __LINE__,
"error parsing auth.require 'require' field: missing '=' "
"(expecting \"valid-user\" or \"user=a|user=b|group=g|host=h\"). "
"error value: %s error near: %s", b->ptr, str);
return 0;
}
if (eq[1] == '|' || eq[1] == '\0') {
log_error(errh, __FILE__, __LINE__,
"error parsing auth.require 'require' field: "
"missing token after '=' "
"(expecting \"valid-user\" or \"user=a|user=b|group=g|host=h\"). "
"error value: %s error near: %s", b->ptr, str);
return 0;
}
switch ((int)(eq - str)) {
case 4:
if (0 == memcmp(str, CONST_STR_LEN("user"))) {
/*("user=" is 5)*/
array_set_key_value(&require->user, str+5, len-5, CONST_STR_LEN(""));
continue;
}
else if (0 == memcmp(str, CONST_STR_LEN("host"))) {
/*("host=" is 5)*/
array_set_key_value(&require->host, str+5, len-5, CONST_STR_LEN(""));
log_error(errh, __FILE__, __LINE__,
"warning parsing auth.require 'require' field: "
"'host' not implemented; field value: %s", b->ptr);
continue;
}
break; /* to error */
case 5:
if (0 == memcmp(str, CONST_STR_LEN("group"))) {
/*("group=" is 6)*/
array_set_key_value(&require->group, str+6, len-6, CONST_STR_LEN(""));
#if 0/*(supported by mod_authn_ldap, but not all other backends)*/
log_error(errh, __FILE__, __LINE__,
"warning parsing auth.require 'require' field: "
"'group' not implemented; field value: %s", b->ptr);
#endif
continue;
}
break; /* to error */
case 10:
if (0 == memcmp(str, CONST_STR_LEN("valid-user"))) {
log_error(errh, __FILE__, __LINE__,
"error parsing auth.require 'require' field: "
"valid user can not be combined with other require rules "
"(expecting \"valid-user\" or "
"\"user=a|user=b|group=g|host=h\"). error value: %s", b->ptr);
return 0;
}
break; /* to error */
default:
break; /* to error */
}
log_error(errh, __FILE__, __LINE__,
"error parsing auth.require 'require' field: "
"invalid/unsupported token "
"(expecting \"valid-user\" or \"user=a|user=b|group=g|host=h\"). "
"error value: %s error near: %s", b->ptr, str);
return 0;
} while (p && *((str = p+1)));
return 1; /* success */
}
static handler_t mod_auth_require_parse_array(const array *value, array * const auth_require, log_error_st *errh)
{
for (uint32_t n = 0; n < value->used; ++n) {
size_t m;
data_array *da_file = (data_array *)value->data[n];
const buffer *method = NULL, *realm = NULL, *require = NULL;
const buffer *nonce_secret = NULL;
const http_auth_scheme_t *auth_scheme;
buffer *algos = NULL;
int algorithm = HTTP_AUTH_DIGEST_SESS;
if (!array_is_kvstring(&da_file->value)) {
log_error(errh, __FILE__, __LINE__,
"unexpected value for auth.require; expected "
"auth.require = ( \"urlpath\" => ( \"option\" => \"value\" ) )");
return HANDLER_ERROR;
}
for (m = 0; m < da_file->value.used; m++) {
if (da_file->value.data[m]->type == TYPE_STRING) {
data_string *ds = (data_string *)da_file->value.data[m];
if (buffer_is_equal_string(&ds->key, CONST_STR_LEN("method"))) {
method = &ds->value;
} else if (buffer_is_equal_string(&ds->key, CONST_STR_LEN("realm"))) {
realm = &ds->value;
} else if (buffer_is_equal_string(&ds->key, CONST_STR_LEN("require"))) {
require = &ds->value;
} else if (buffer_is_equal_string(&ds->key, CONST_STR_LEN("algorithm"))) {
algos = &ds->value;
} else if (buffer_is_equal_string(&ds->key, CONST_STR_LEN("nonce_secret"))
|| buffer_is_equal_string(&ds->key, CONST_STR_LEN("nonce-secret"))) {
nonce_secret = &ds->value;
} else {
log_error(errh, __FILE__, __LINE__,
"the field is unknown in: "
"auth.require = ( \"...\" => ( ..., -> \"%s\" <- => \"...\" ) )",
da_file->value.data[m]->key.ptr);
return HANDLER_ERROR;
}
} else {
log_error(errh, __FILE__, __LINE__,
"a string was expected for: "
"auth.require = ( \"...\" => ( ..., -> \"%s\" <- => \"...\" ) )",
da_file->value.data[m]->key.ptr);
return HANDLER_ERROR;
}
}
if (!method || buffer_is_blank(method)) {
log_error(errh, __FILE__, __LINE__,
"the method field is missing or blank in: "
"auth.require = ( \"...\" => ( ..., \"method\" => \"...\" ) )");
return HANDLER_ERROR;
} else {
auth_scheme = http_auth_scheme_get(method);
if (NULL == auth_scheme) {
log_error(errh, __FILE__, __LINE__,
"unknown method %s (e.g. \"basic\", \"digest\" or \"extern\") in "
"auth.require = ( \"...\" => ( ..., \"method\" => \"...\") )", method->ptr);
return HANDLER_ERROR;
}
}
if (!realm) {
log_error(errh, __FILE__, __LINE__,
"the realm field is missing in: "
"auth.require = ( \"...\" => ( ..., \"realm\" => \"...\" ) )");
return HANDLER_ERROR;
}
if (!require || buffer_is_blank(require)) {
log_error(errh, __FILE__, __LINE__,
"the require field is missing or blank in: "
"auth.require = ( \"...\" => ( ..., \"require\" => \"...\" ) )");
return HANDLER_ERROR;
}
if (!algos || buffer_is_blank(algos)) {
algorithm |= HTTP_AUTH_DIGEST_MD5;
} else if (!mod_auth_algorithms_parse(&algorithm, algos)) {
log_error(errh, __FILE__, __LINE__,
"invalid algorithm in: "
"auth.require = ( \"...\" => ( ..., \"algorithm\" => \"...\" ) )");
return HANDLER_ERROR;
}
if (require) { /*(always true at this point)*/
data_auth * const dauth = data_auth_init();
buffer_copy_buffer(&dauth->key, &da_file->key);
dauth->require->scheme = auth_scheme;
dauth->require->algorithm = algorithm;
dauth->require->realm = realm;
dauth->require->nonce_secret = nonce_secret; /*(NULL is ok)*/
if (!mod_auth_require_parse(dauth->require, require, errh)) {
dauth->fn->free((data_unset *)dauth);
return HANDLER_ERROR;
}
array_insert_unique(auth_require, (data_unset *)dauth);
}
}
return HANDLER_GO_ON;
}
static void mod_auth_merge_config_cpv(plugin_config * const pconf, const config_plugin_value_t * const cpv) {
switch (cpv->k_id) { /* index into static config_plugin_keys_t cpk[] */
case 0: /* auth.backend */
if (cpv->vtype == T_CONFIG_LOCAL)
pconf->auth_backend = cpv->v.v;
break;
case 1: /* auth.require */
if (cpv->vtype == T_CONFIG_LOCAL)
pconf->auth_require = cpv->v.v;
break;
case 2: /* auth.extern-authn */
pconf->auth_extern_authn = cpv->v.u;
break;
case 3: /* auth.cache */
if (cpv->vtype == T_CONFIG_LOCAL)
pconf->auth_cache = cpv->v.v;
break;
default:/* should not happen */
return;
}
}
static void mod_auth_merge_config(plugin_config * const pconf, const config_plugin_value_t *cpv) {
do {
mod_auth_merge_config_cpv(pconf, cpv);
} while ((++cpv)->k_id != -1);
}
static void mod_auth_patch_config(request_st * const r, plugin_data * const p) {
p->conf = p->defaults; /* copy small struct instead of memcpy() */
/*memcpy(&p->conf, &p->defaults, sizeof(plugin_config));*/
for (int i = 1, used = p->nconfig; i < used; ++i) {
if (config_check_cond(r, (uint32_t)p->cvlist[i].k_id))
mod_auth_merge_config(&p->conf, p->cvlist + p->cvlist[i].v.u2[0]);
}
}
SETDEFAULTS_FUNC(mod_auth_set_defaults) {
static const config_plugin_keys_t cpk[] = {
{ CONST_STR_LEN("auth.backend"),
T_CONFIG_STRING,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("auth.require"),
T_CONFIG_ARRAY_KVARRAY,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("auth.extern-authn"),
T_CONFIG_BOOL,
T_CONFIG_SCOPE_CONNECTION }
,{ CONST_STR_LEN("auth.cache"),
T_CONFIG_ARRAY,
T_CONFIG_SCOPE_CONNECTION }
,{ NULL, 0,
T_CONFIG_UNSET,
T_CONFIG_SCOPE_UNSET }
};
plugin_data * const p = p_d;
if (!config_plugin_values_init(srv, p, cpk, "mod_auth"))
return HANDLER_ERROR;
/* process and validate config directives
* (init i to 0 if global context; to 1 to skip empty global context) */
for (int i = !p->cvlist[0].v.u2[1]; i < p->nconfig; ++i) {
config_plugin_value_t *cpv = p->cvlist + p->cvlist[i].v.u2[0];
for (; -1 != cpv->k_id; ++cpv) {
switch (cpv->k_id) {
case 0: /* auth.backend */
if (!buffer_is_blank(cpv->v.b)) {
const http_auth_backend_t * const auth_backend =
http_auth_backend_get(cpv->v.b);
if (NULL == auth_backend) {
log_error(srv->errh, __FILE__, __LINE__,
"auth.backend not supported: %s", cpv->v.b->ptr);
return HANDLER_ERROR;
}
*(const http_auth_backend_t **)&cpv->v.v = auth_backend;
cpv->vtype = T_CONFIG_LOCAL;
}
break;
case 1: /* auth.require */
{
array * const a = array_init(4);
if (HANDLER_GO_ON !=
mod_auth_require_parse_array(cpv->v.a, a, srv->errh)) {
array_free(a);
return HANDLER_ERROR;
}
cpv->v.a = a;
cpv->vtype = T_CONFIG_LOCAL;
}
break;
case 2: /* auth.extern-authn */
break;
case 3: /* auth.cache */
cpv->v.v = http_auth_cache_init(cpv->v.a);
cpv->vtype = T_CONFIG_LOCAL;
break;
default:/* should not happen */
break;
}
}
}
/* initialize p->defaults from global config context */
if (p->nconfig > 0 && p->cvlist->v.u2[1]) {
const config_plugin_value_t *cpv = p->cvlist + p->cvlist->v.u2[0];
if (-1 != cpv->k_id)
mod_auth_merge_config(&p->defaults, cpv);
}
return HANDLER_GO_ON;
}
static handler_t mod_auth_uri_handler(request_st * const r, void *p_d) {
plugin_data *p = p_d;
data_auth *dauth;
mod_auth_patch_config(r, p);
if (p->conf.auth_require == NULL) return HANDLER_GO_ON;
/* search auth directives for first prefix match against URL path */
/* if we have a case-insensitive FS we have to lower-case the URI here too */
dauth = (!r->conf.force_lowercase_filenames)
? (data_auth *)array_match_key_prefix(p->conf.auth_require, &r->uri.path)
: (data_auth *)array_match_key_prefix_nc(p->conf.auth_require, &r->uri.path);
if (NULL == dauth) return HANDLER_GO_ON;
{
const http_auth_scheme_t * const scheme = dauth->require->scheme;
if (p->conf.auth_extern_authn) {
const buffer *vb = http_header_env_get(r, CONST_STR_LEN("REMOTE_USER"));
if (NULL != vb && http_auth_match_rules(dauth->require, vb->ptr, NULL, NULL)) {
return HANDLER_GO_ON;
}
}
return scheme->checkfn(r, scheme->p_d, dauth->require, p->conf.auth_backend);
}
}
int mod_auth_plugin_init(plugin *p);
int mod_auth_plugin_init(plugin *p) {
p->version = LIGHTTPD_VERSION_ID;
p->name = "auth";
p->init = mod_auth_init;
p->set_defaults = mod_auth_set_defaults;
p->handle_trigger = mod_auth_periodic;
p->handle_uri_clean = mod_auth_uri_handler;
p->cleanup = mod_auth_free;
return 0;
}
/*
* auth schemes (basic, digest, extern)
*
* (could be in separate file from mod_auth.c as long as registration occurs)
*/
#include "sys-crypto-md.h"
#include "base64.h"
#include "rand.h"
#include "http_header.h"
__attribute_cold__
__attribute_noinline__
static handler_t
mod_auth_send_400_bad_request (request_st * const r)
{
/* a field was missing or invalid */
r->http_status = 400; /* Bad Request */
r->handler_module = NULL;
return HANDLER_FINISHED;
}
__attribute_noinline__
static handler_t
mod_auth_send_401_unauthorized_basic (request_st * const r, const buffer * const realm)
{
r->http_status = 401;
r->handler_module = NULL;
buffer_append_str3(
http_header_response_set_ptr(r, HTTP_HEADER_WWW_AUTHENTICATE,
CONST_STR_LEN("WWW-Authenticate")),
CONST_STR_LEN("Basic realm=\""),
BUF_PTR_LEN(realm),
CONST_STR_LEN("\", charset=\"UTF-8\""));
return HANDLER_FINISHED;
}
__attribute_cold__
static handler_t
mod_auth_basic_misconfigured (request_st * const r, const struct http_auth_backend_t * const backend)
{
if (NULL == backend)
log_error(r->conf.errh, __FILE__, __LINE__,
"auth.backend not configured for %s", r->uri.path.ptr);
else
log_error(r->conf.errh, __FILE__, __LINE__,
"auth.require \"method\" => \"basic\" invalid "
"(try \"digest\"?) for %s", r->uri.path.ptr);
r->http_status = 500;
r->handler_module = NULL;
return HANDLER_FINISHED;
}
static handler_t
mod_auth_check_basic(request_st * const r, void *p_d, const struct http_auth_require_t * const require, const struct http_auth_backend_t * const backend)
{
if (NULL == backend || NULL == backend->basic)
return mod_auth_basic_misconfigured(r, backend);
const buffer * const vb =
http_header_request_get(r, HTTP_HEADER_AUTHORIZATION,
CONST_STR_LEN("Authorization"));
if (NULL == vb || !buffer_eq_icase_ssn(vb->ptr, CONST_STR_LEN("Basic ")))
return mod_auth_send_401_unauthorized_basic(r, require->realm);
#ifdef __COVERITY__
if (buffer_clen(vb) < sizeof("Basic ")-1)
return mod_auth_send_400_bad_request(r);
#endif
size_t ulen = buffer_clen(vb) - (sizeof("Basic ")-1);
size_t pwlen;
char *pw;
char user[1024];
/* base64-decode Authorization into username:password string;
* limit base64-decoded username:password string to fit into 1k buf */
if (ulen > 1363) /*(1363/4*3+3 = 1023)*/
return mod_auth_send_401_unauthorized_basic(r, require->realm);
/* coverity[overflow_sink : FALSE] */
ulen = li_base64_dec((unsigned char *)user, sizeof(user),
vb->ptr+sizeof("Basic ")-1, ulen, BASE64_STANDARD);
if (0 == ulen) {
log_error(r->conf.errh, __FILE__, __LINE__,
"decoding base64-string failed %s", vb->ptr+sizeof("Basic ")-1);
return mod_auth_send_400_bad_request(r);
}
user[ulen] = '\0';
pw = memchr(user, ':', ulen);
if (NULL == pw) {
log_error(r->conf.errh, __FILE__, __LINE__, "missing ':' in %s", user);
return mod_auth_send_400_bad_request(r);
}
*pw++ = '\0';
pwlen = (size_t)(user + ulen - pw);
ulen = (size_t)(pw - 1 - user);
plugin_data * const p = p_d;
splay_tree ** sptree = p->conf.auth_cache
? &p->conf.auth_cache->sptree
: NULL;
http_auth_cache_entry *ae = NULL;
handler_t rc = HANDLER_ERROR;
int ndx = -1;
if (sptree) {
ndx = http_auth_cache_hash(require, user, ulen);
ae = http_auth_cache_query(sptree, ndx);
if (ae && ae->require == require
&& ulen == ae->ulen && 0 == memcmp(user, ae->username, ulen))
rc = ck_memeq_const_time(ae->pwdigest, ae->dlen, pw, pwlen)
? HANDLER_GO_ON
: HANDLER_ERROR;
else /*(not found or hash collision)*/
ae = NULL;
}
if (NULL == ae) {
const buffer userb = { user, ulen+1, 0 };
rc = backend->basic(r, backend->p_d, require, &userb, pw);
}
switch (rc) {
case HANDLER_GO_ON:
http_auth_setenv(r, user, ulen, CONST_STR_LEN("Basic"));
if (sptree && NULL == ae) { /*(cache (new) successful result)*/
ae = http_auth_cache_entry_init(require, 0, user, ulen, pw, pwlen);
http_auth_cache_insert(sptree, ndx, ae, http_auth_cache_entry_free);
}
break;
case HANDLER_WAIT_FOR_EVENT:
case HANDLER_FINISHED:
break;
case HANDLER_ERROR:
default:
log_error(r->conf.errh, __FILE__, __LINE__,
"password doesn't match for %s username: %s IP: %s",
r->uri.path.ptr, user, r->con->dst_addr_buf.ptr);
r->keep_alive = -1; /*(disable keep-alive if bad password)*/
rc = mod_auth_send_401_unauthorized_basic(r, require->realm);
break;
}
ck_memzero(pw, pwlen);
return rc;
}
enum http_auth_digest_params_e {
e_username = 0
,e_realm
,e_nonce
,e_uri
,e_algorithm
,e_qop
,e_cnonce
,e_nc
,e_response
,http_auth_digest_params_sz /*(last item)*/
};
typedef struct http_auth_digest_params_t {
const char *ptr[http_auth_digest_params_sz];
uint16_t len[http_auth_digest_params_sz];
unix_time64_t send_nextnonce_ts;
unsigned char rdigest[MD_DIGEST_LENGTH_MAX]; /*(last member)*/
} http_auth_digest_params_t;
static void
mod_auth_digest_mutate (http_auth_info_t * const ai, const http_auth_digest_params_t * const dp, const buffer * const method)
{
force_assert(method);
li_md_iov_fn digest_iov = MD5_iov;
/* (ai->dalgo & HTTP_AUTH_DIGEST_MD5) default */
#ifdef USE_LIB_CRYPTO
if (ai->dalgo & HTTP_AUTH_DIGEST_SHA256)
digest_iov = SHA256_iov;
#ifdef USE_LIB_CRYPTO_SHA512_256
else if (ai->dalgo & HTTP_AUTH_DIGEST_SHA512_256)
digest_iov = SHA512_256_iov;
#endif
#endif
size_t n;
struct const_iovec iov[11];
char a1[MD_DIGEST_LENGTH_MAX*2+8]; /*(+1 for li_tohex(); +8 for align)*/
char a2[MD_DIGEST_LENGTH_MAX*2+8]; /*(+1 for li_tohex(); +8 for align)*/
li_tohex(a1, sizeof(a1), (const char *)ai->digest, ai->dlen);
if (ai->dalgo & HTTP_AUTH_DIGEST_SESS) {
/* http://www.rfc-editor.org/errata_search.php?rfc=2617
* Errata ID: 1649 */
iov[0].iov_base = a1;
iov[0].iov_len = ai->dlen*2;
iov[1].iov_base = ":";
iov[1].iov_len = 1;
iov[2].iov_base = dp->ptr[e_nonce];
iov[2].iov_len = dp->len[e_nonce];
iov[3].iov_base = ":";
iov[3].iov_len = 1;
iov[4].iov_base = dp->ptr[e_cnonce];
iov[4].iov_len = dp->len[e_cnonce];
digest_iov(ai->digest, iov, 5);
li_tohex(a1, sizeof(a1), (const char *)ai->digest, ai->dlen);
}
/* calculate H(A2) */
iov[0].iov_base = method->ptr;
iov[0].iov_len = buffer_clen(method);
iov[1].iov_base = ":";
iov[1].iov_len = 1;
iov[2].iov_base = dp->ptr[e_uri];
iov[2].iov_len = dp->len[e_uri];
n = 3;
#if 0
/* qop=auth-int not supported, already checked in caller */
if (dp->ptr[e_qop] && buffer_eq_icase_ss(dp->ptr[e_qop], dp->len[e_qop],
CONST_STR_LEN("auth-int"))) {
iov[3].iov_base = ":";
iov[3].iov_len = 1;
iov[4].iov_base = [body checksum];
iov[4].iov_len = ai->dlen*2;
n = 5;
}
#endif
digest_iov(ai->digest, iov, n);
li_tohex(a2, sizeof(a2), (const char *)ai->digest, ai->dlen);
/* calculate response */
iov[0].iov_base = a1;
iov[0].iov_len = ai->dlen*2;
iov[1].iov_base = ":";
iov[1].iov_len = 1;
iov[2].iov_base = dp->ptr[e_nonce];
iov[2].iov_len = dp->len[e_nonce];
iov[3].iov_base = ":";
iov[3].iov_len = 1;
n = 4;
if (dp->len[e_qop]) {
iov[4].iov_base = dp->ptr[e_nc];
iov[4].iov_len = dp->len[e_nc];
iov[5].iov_base = ":";
iov[5].iov_len = 1;
iov[6].iov_base = dp->ptr[e_cnonce];
iov[6].iov_len = dp->len[e_cnonce];
iov[7].iov_base = ":";
iov[7].iov_len = 1;
iov[8].iov_base = dp->ptr[e_qop];
iov[8].iov_len = dp->len[e_qop];
iov[9].iov_base = ":";
iov[9].iov_len = 1;
n = 10;
}
iov[n].iov_base = a2;
iov[n].iov_len = ai->dlen*2;
digest_iov(ai->digest, iov, n+1);
}
static void
mod_auth_append_nonce (buffer *b, unix_time64_t cur_ts, const struct http_auth_require_t *require, int dalgo, int *rndptr)
{
buffer_append_uint_hex(b, (uintmax_t)cur_ts);
buffer_append_string_len(b, CONST_STR_LEN(":"));
const buffer * const nonce_secret = require->nonce_secret;
int rnd;
if (NULL == nonce_secret)
rnd = rndptr ? *rndptr : li_rand_pseudo();
else { /*(do not directly expose random number generator single value)*/
rndptr
? (void)(rnd = *rndptr)
: li_rand_pseudo_bytes((unsigned char *)&rnd, sizeof(rnd));
buffer_append_uint_hex(b, (uintmax_t)rnd);
buffer_append_string_len(b, CONST_STR_LEN(":"));
}
size_t n;
struct const_iovec iov[3];
#if 0
char a1[LI_ITOSTRING_LENGTH];
char a2[LI_ITOSTRING_LENGTH];
iov[0].iov_base = a1;
iov[0].iov_len = li_itostrn(a1, sizeof(a1), cur_ts);
iov[1].iov_base = a2;
iov[1].iov_len = li_itostrn(a2, sizeof(a2), rnd);
#else
iov[0].iov_base = &cur_ts;
iov[0].iov_len = sizeof(cur_ts);
iov[1].iov_base = &rnd;
iov[1].iov_len = sizeof(rnd);
#endif
n = 2;
if (nonce_secret) {
iov[2].iov_base = nonce_secret->ptr;
iov[2].iov_len = buffer_clen(nonce_secret);
n = 3;
}
unsigned char h[MD_DIGEST_LENGTH_MAX];
switch (dalgo) {
#ifdef USE_LIB_CRYPTO
#ifdef USE_LIB_CRYPTO_SHA512_256
case HTTP_AUTH_DIGEST_SHA512_256:
SHA512_256_iov(h, iov, n);
n = HTTP_AUTH_DIGEST_SHA512_256_BINLEN;
break;
#endif
case HTTP_AUTH_DIGEST_SHA256:
SHA256_iov(h, iov, n);
n = HTTP_AUTH_DIGEST_SHA256_BINLEN;
break;
#endif
/*case HTTP_AUTH_DIGEST_MD5:*/
default:
MD5_iov(h, iov, n);
n = HTTP_AUTH_DIGEST_MD5_BINLEN;
break;
}
li_tohex(buffer_extend(b, n*2), n*2+1, (const char *)h, n);
}
static void
mod_auth_digest_www_authenticate (buffer *b, unix_time64_t cur_ts, const struct http_auth_require_t *require, int nonce_stale)
{
int algos = nonce_stale ? nonce_stale : require->algorithm;
int n = 0;
int algoid[3];
unsigned int algolen[3];
const char *algoname[3];
#ifdef USE_LIB_CRYPTO
#ifdef USE_LIB_CRYPTO_SHA512_256
if (algos & HTTP_AUTH_DIGEST_SHA512_256) {
algoid[n] = HTTP_AUTH_DIGEST_SHA512_256;
algoname[n] = "SHA-512-256";
algolen[n] = sizeof("SHA-512-256")-1;
++n;
}
#endif
if (algos & HTTP_AUTH_DIGEST_SHA256) {
algoid[n] = HTTP_AUTH_DIGEST_SHA256;
algoname[n] = "SHA-256";
algolen[n] = sizeof("SHA-256")-1;
++n;
}
#endif
if (algos & HTTP_AUTH_DIGEST_MD5) {
algoid[n] = HTTP_AUTH_DIGEST_MD5;
algoname[n] = "MD5";
algolen[n] = sizeof("MD5")-1;
++n;
}
buffer_clear(b);
for (int i = 0; i < n; ++i) {
struct const_iovec iov[] = {
{ CONST_STR_LEN("\r\nWWW-Authenticate: ") }
,{ CONST_STR_LEN("Digest realm=\"") }
,{ BUF_PTR_LEN(require->realm) }
,{ CONST_STR_LEN("\", charset=\"UTF-8\", algorithm=") }
,{ algoname[i], algolen[i] }
,{ CONST_STR_LEN(", nonce=\"") }
};
buffer_append_iovec(b, iov+(0==i), sizeof(iov)/sizeof(*iov)-(0==i));
mod_auth_append_nonce(b, cur_ts, require, algoid[i], NULL);
buffer_append_string_len(b, CONST_STR_LEN("\", qop=\"auth\""));
if (nonce_stale) {
buffer_append_string_len(b, CONST_STR_LEN(", stale=true"));
}
}
}
__attribute_noinline__
static handler_t
mod_auth_send_401_unauthorized_digest(request_st * const r, const struct http_auth_require_t * const require, int nonce_stale)
{
r->http_status = 401;
r->handler_module = NULL;
mod_auth_digest_www_authenticate(
http_header_response_set_ptr(r, HTTP_HEADER_WWW_AUTHENTICATE,
CONST_STR_LEN("WWW-Authenticate")),
log_epoch_secs, require, nonce_stale);
return HANDLER_FINISHED;
}
static void
mod_auth_digest_authentication_info (buffer *b, unix_time64_t cur_ts, const struct http_auth_require_t *require, int dalgo)
{
buffer_clear(b);
buffer_append_string_len(b, CONST_STR_LEN("nextnonce=\""));
mod_auth_append_nonce(b, cur_ts, require, dalgo, NULL);
buffer_append_string_len(b, CONST_STR_LEN("\""));
}
static handler_t
mod_auth_digest_get (request_st * const r, void *p_d, const struct http_auth_require_t * const require, const struct http_auth_backend_t * const backend, http_auth_info_t * const ai)
{
plugin_data * const p = p_d;
splay_tree **sptree = p->conf.auth_cache
? &p->conf.auth_cache->sptree
: NULL;
http_auth_cache_entry *ae = NULL;
handler_t rc = HANDLER_GO_ON;
int ndx = -1;
if (sptree) {
ndx = http_auth_cache_hash(require, ai->username, ai->ulen);
ae = http_auth_cache_query(sptree, ndx);
if (ae && ae->require == require
&& ae->dalgo == ai->dalgo
&& ae->dlen == ai->dlen
&& ae->ulen == ai->ulen
&& 0 == memcmp(ae->username, ai->username, ai->ulen)) {
memcpy(ai->digest, ae->pwdigest, ai->dlen);
}
else /*(not found or hash collision)*/
ae = NULL;
}
if (NULL == ae)
rc = backend->digest(r, backend->p_d, ai);
switch (rc) {
case HANDLER_GO_ON:
break;
case HANDLER_WAIT_FOR_EVENT:
return HANDLER_WAIT_FOR_EVENT;
case HANDLER_FINISHED:
return HANDLER_FINISHED;
case HANDLER_ERROR:
default:
r->keep_alive = -1; /*(disable keep-alive if unknown user)*/
return mod_auth_send_401_unauthorized_digest(r, require, 0);
}
if (sptree && NULL == ae) { /*(cache digest from backend)*/
ae = http_auth_cache_entry_init(require, ai->dalgo, ai->username,
ai->ulen, (char *)ai->digest, ai->dlen);
http_auth_cache_insert(sptree, ndx, ae, http_auth_cache_entry_free);
}
return rc;
}
__attribute_cold__
static handler_t
mod_auth_digest_misconfigured (request_st * const r, const struct http_auth_backend_t * const backend)
{
if (NULL == backend)
log_error(r->conf.errh, __FILE__, __LINE__,
"auth.backend not configured for %s", r->uri.path.ptr);
else
log_error(r->conf.errh, __FILE__, __LINE__,
"auth.require \"method\" => \"digest\" invalid "
"(try \"basic\"?) for %s", r->uri.path.ptr);
r->http_status = 500;
r->handler_module = NULL;
return HANDLER_FINISHED;
}
static void
mod_auth_digest_parse_authorization (http_auth_digest_params_t * const dp, const char *c)
{
struct digest_kv {
const char *key;
uint32_t klen;
enum http_auth_digest_params_e id;
};
static const struct digest_kv dkv[] = {
{ CONST_STR_LEN("username"), e_username },
{ CONST_STR_LEN("realm"), e_realm },
{ CONST_STR_LEN("nonce"), e_nonce },
{ CONST_STR_LEN("uri"), e_uri },
{ CONST_STR_LEN("algorithm"), e_algorithm },
{ CONST_STR_LEN("qop"), e_qop },
{ CONST_STR_LEN("cnonce"), e_cnonce },
{ CONST_STR_LEN("nc"), e_nc },
{ CONST_STR_LEN("response"), e_response },
{ NULL, 0, http_auth_digest_params_sz }
};
/* parse credentials from client */
/* (caller must pass c pointing to string after "Digest ") */
for (const char *e; *c; c++) {
/* skip whitespaces */
while (*c == ' ' || *c == '\t' || *c == ',') ++c;
if (!*c) break;
for (e = c; *e!='=' && *e!=' ' && *e!='\t' && *e!='\0'; ++e) ;
const uint32_t tlen = (uint32_t)(e - c);
for (int i = 0; dkv[i].key; ++i) {
if (tlen != dkv[i].klen || 0 != memcmp(c, dkv[i].key, tlen))
continue;
c += tlen;
/* detect and step over '='; ignore BWS (bad whitespace) */
if (__builtin_expect( (*c != '='), 0)) {
while (*c == ' ' || *c == '\t') ++c;
if (*c != '=') return; /*(including '\0')*/
}
do { ++c; } while (*c == ' ' || *c == '\t');
if (*c == '"') {
for (e = ++c; *e != '"' && *e != '\0'; ++e) {
if (*e == '\\' && *++e == '\0') return;
}
if (*e != '"') return;
/* value with "..." *//*(XXX: quoted value not unescaped)*/
}
else {
for (e = c; *e!=',' && *e!=' ' && *e!='\t' && *e!='\0'; ++e) ;
/* value without "..." */
}
dp->ptr[dkv[i].id] = c;
dp->len[dkv[i].id] = (uint16_t)(e - c);
c = e;
if (*c != ',') {
/*(could more strictly check for linear whitespace)*/
c = strchr(c, ',');
if (!c) return;
}
break;
}
}
}
static handler_t
mod_auth_digest_validate_params (request_st * const r, const struct http_auth_require_t * const require, http_auth_digest_params_t * const dp, http_auth_info_t * const ai)
{
/* check for required parameters */
if ((!dp->ptr[e_qop] || (dp->ptr[e_nc] && dp->ptr[e_cnonce]))
&& dp->ptr[e_username]
&& dp->ptr[e_realm]
&& dp->ptr[e_nonce]
&& dp->ptr[e_uri]
&& dp->ptr[e_response]) {
ai->username = dp->ptr[e_username];
ai->ulen = dp->len[e_username];
ai->realm = dp->ptr[e_realm];
ai->rlen = dp->len[e_realm];
}
else {
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: missing field");
return mod_auth_send_400_bad_request(r);
}
if (!buffer_eq_slen(require->realm, ai->realm, ai->rlen)) {
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: realm mismatch");
return mod_auth_send_401_unauthorized_digest(r, require, 0);
}
if (!mod_auth_algorithm_parse(ai,dp->ptr[e_algorithm],dp->len[e_algorithm])
|| !(require->algorithm & ai->dalgo & ~HTTP_AUTH_DIGEST_SESS)) {
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: (%.*s): invalid",
(int)dp->len[e_algorithm], dp->ptr[e_algorithm]);
return mod_auth_send_401_unauthorized_digest(r, require, 0);
}
/* *-sess requires nonce and cnonce */
if ((ai->dalgo & HTTP_AUTH_DIGEST_SESS)
&& (!dp->ptr[e_nonce] || !dp->ptr[e_cnonce])) {
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: (%.*s): missing field",
(int)dp->len[e_algorithm], dp->ptr[e_algorithm]);
return mod_auth_send_400_bad_request(r);
}
if (0 != li_hex2bin(dp->rdigest, sizeof(dp->rdigest),
dp->ptr[e_response], dp->len[e_response])
|| dp->len[e_response] != (ai->dlen << 1)) {
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: (%s): invalid format", dp->ptr[e_response]);
return mod_auth_send_400_bad_request(r);
}
if (dp->ptr[e_qop]&& buffer_eq_icase_ss(dp->ptr[e_qop], dp->len[e_qop],
CONST_STR_LEN("auth-int"))) {
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: qop=auth-int not supported");
return mod_auth_send_400_bad_request(r);
}
/* detect if attacker is attempting to reuse valid digest for one uri
* on a different request uri. Might also happen if intermediate proxy
* altered client request line. (Altered request would not result in
* the same digest as that calculated by the client.)
* Internal redirects such as with mod_rewrite will modify request uri.
* Reauthentication is done to detect crossing auth realms, but this
* uri validation step is bypassed. r->target_orig is
* original request-target sent in client request. */
if (!buffer_eq_slen(&r->target_orig, dp->ptr[e_uri], dp->len[e_uri])) {
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: auth failed: uri mismatch (%s != %.*s), IP: %s",
r->target_orig.ptr, (int)dp->len[e_uri], dp->ptr[e_uri],
r->con->dst_addr_buf.ptr);
return mod_auth_send_400_bad_request(r);
}
return HANDLER_GO_ON;
}
static handler_t
mod_auth_digest_validate_nonce (request_st * const r, const struct http_auth_require_t * const require, http_auth_digest_params_t * const dp, http_auth_info_t * const ai)
{
/* check age of nonce. Note, random data is used in nonce generation
* in mod_auth_send_401_unauthorized_digest(). If that were replaced
* with nanosecond time, then nonce secret would remain unique enough
* for the purposes of Digest auth, and would be reproducible (and
* verifiable) if nanoseconds were included with seconds as part of the
* nonce "timestamp:secret". However, doing so would expose a high
* precision timestamp of the system to attackers. timestamp in nonce
* could theoretically be modified and still produce same md5sum, but
* that is highly unlikely within a 10 min (moving) window of valid
* time relative to current time (now).
* If it is desired to validate that nonces were generated by server,
* then specify auth.require = ( ... => ( "secret" => "..." ) )
* When secret is specified, then instead of nanoseconds, the random
* data value (included for unique nonces) will be exposed in the nonce
* along with the timestamp, and the additional secret will be used to
* validate that the server generated the nonce using that secret. */
unix_time64_t ts = 0;
const unsigned char * const nonce = (unsigned char *)dp->ptr[e_nonce];
int i;
for (i = 0; i < 16 && light_isxdigit(nonce[i]); ++i)
ts = (unix_time64_t)((uint64_t)ts << 4) | hex2int(nonce[i]);
const unix_time64_t cur_ts = log_epoch_secs;
if (nonce[i] != ':' || ts > cur_ts || cur_ts - ts > 600) { /*(10 mins)*/
/* nonce is stale; have client regenerate digest */
return mod_auth_send_401_unauthorized_digest(r, require, ai->dalgo);
}
if (cur_ts - ts > 540) /*(9 mins)*/
dp->send_nextnonce_ts = cur_ts;
if (require->nonce_secret) {
unsigned int rnd = 0;
for (int j = i+8; i < j && light_isxdigit(nonce[i]); ++i) {
rnd = (rnd << 4) + hex2int(nonce[i]);
}
if (nonce[i] != ':') {
/* nonce is invalid;
* expect extra field w/ require->nonce_secret */
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: nonce invalid");
return mod_auth_send_400_bad_request(r);
}
buffer * const tb = r->tmp_buf;
buffer_clear(tb);
mod_auth_append_nonce(tb, cur_ts, require, ai->dalgo, (int *)&rnd);
if (!buffer_eq_slen(tb, dp->ptr[e_nonce], dp->len[e_nonce])) {
/* nonce not generated using current require->nonce_secret */
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: nonce mismatch");
return mod_auth_send_401_unauthorized_digest(r, require, 0);
}
}
return HANDLER_GO_ON;
}
static handler_t
mod_auth_check_digest (request_st * const r, void *p_d, const struct http_auth_require_t * const require, const struct http_auth_backend_t * const backend)
{
if (NULL == backend || NULL == backend->digest)
return mod_auth_digest_misconfigured(r, backend);
const buffer * const vb =
http_header_request_get(r, HTTP_HEADER_AUTHORIZATION,
CONST_STR_LEN("Authorization"));
if (NULL == vb || !buffer_eq_icase_ssn(vb->ptr, CONST_STR_LEN("Digest ")))
return mod_auth_send_401_unauthorized_digest(r, require, 0);
#ifdef __COVERITY__
if (buffer_clen(vb) < sizeof("Digest ")-1)
return mod_auth_send_400_bad_request(r);
#endif
http_auth_digest_params_t dp;
http_auth_info_t ai;
handler_t rc;
memset(&dp, 0, sizeof(dp) - sizeof(dp.rdigest));
mod_auth_digest_parse_authorization(&dp, vb->ptr + sizeof("Digest ")-1);
rc = mod_auth_digest_validate_params(r, require, &dp, &ai);
if (__builtin_expect( (HANDLER_GO_ON != rc), 0))
return rc;
rc = mod_auth_digest_validate_nonce(r, require, &dp, &ai);
if (__builtin_expect( (HANDLER_GO_ON != rc), 0))
return rc;
rc = mod_auth_digest_get(r, p_d, require, backend, &ai);
if (__builtin_expect( (HANDLER_GO_ON != rc), 0))
return rc;
mod_auth_digest_mutate(&ai, &dp, http_method_buf(r->http_method));
if (!ck_memeq_const_time_fixed_len(dp.rdigest, ai.digest, ai.dlen)) {
/*ck_memzero(ai.digest, ai.dlen);*//*skip clear since mutated*/
/* digest not ok */
log_error(r->conf.errh, __FILE__, __LINE__,
"digest: auth failed for %.*s: wrong password, IP: %s",
(int)ai.ulen, ai.username, r->con->dst_addr_buf.ptr);
r->keep_alive = -1; /*(disable keep-alive if bad password)*/
return mod_auth_send_401_unauthorized_digest(r, require, 0);
}
/*ck_memzero(ai.digest, ai.dlen);*//* skip clear since mutated */
/* check authorization (authz); string args must be '\0'-terminated) */
buffer * const tb = r->tmp_buf;
buffer_copy_string_len(tb, ai.username, ai.ulen);
if (!http_auth_match_rules(require, tb->ptr, NULL, NULL))
return mod_auth_send_401_unauthorized_digest(r, require, 0);
if (dp.send_nextnonce_ts) {
/*(send nextnonce when expiration is approaching)*/
mod_auth_digest_authentication_info(
http_header_response_set_ptr(r, HTTP_HEADER_OTHER,
CONST_STR_LEN("Authentication-Info")),
dp.send_nextnonce_ts /*(cur_ts)*/, require, ai.dalgo);
}
http_auth_setenv(r, ai.username, ai.ulen, CONST_STR_LEN("Digest"));
return HANDLER_GO_ON;
}
static handler_t mod_auth_check_extern(request_st * const r, void *p_d, const struct http_auth_require_t * const require, const struct http_auth_backend_t * const backend) {
/* require REMOTE_USER already set */
const buffer *vb = http_header_env_get(r, CONST_STR_LEN("REMOTE_USER"));
UNUSED(p_d);
UNUSED(backend);
if (NULL != vb && http_auth_match_rules(require, vb->ptr, NULL, NULL)) {
return HANDLER_GO_ON;
} else {
r->http_status = 401;
r->handler_module = NULL;
return HANDLER_FINISHED;
}
}