/* $OpenBSD: mod_auth_digest.c,v 1.22 2008/05/25 11:46:27 mbalmer Exp $ */
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*
* Portions of this software are based upon public domain software
* originally written at the National Center for Supercomputing Applications,
* University of Illinois, Urbana-Champaign.
*/
/*
* mod_auth_digest: MD5 digest authentication
*
* Originally by Alexei Kosut
* Updated to RFC-2617 by Ronald Tschalär
* based on mod_auth, by Rob McCool and Robert S. Thau
*
* This module an updated version of modules/standard/mod_digest.c
* However, it has not been extensively tested yet, and is therefore
* currently marked experimental. Send problem reports to me
* (ronald@innovation.ch)
*
* Requires either /dev/random (or equivalent) or the truerand library,
* available for instance from
* ftp://research.att.com/dist/mab/librand.shar
*
* Open Issues:
* - qop=auth-int (when streams and trailer support available)
* - nonce-format configurability
* - Proxy-Authorization-Info header is set by this module, but is
* currently ignored by mod_proxy (needs patch to mod_proxy)
* - generating the secret takes a while (~ 8 seconds) if using the
* truerand library
* - The source of the secret should be run-time directive (with server
* scope: RSRC_CONF). However, that could be tricky when trying to
* choose truerand vs. file...
* - shared-mem not completely tested yet. Seems to work ok for me,
* but... (definitely won't work on Windoze)
* - Sharing a realm among multiple servers has following problems:
* o Server name and port can't be included in nonce-hash
* (we need two nonce formats, which must be configured explicitly)
* o Nonce-count check can't be for equal, or then nonce-count checking
* must be disabled. What we could do is the following:
* (expected < received) ? set expected = received : issue error
* The only problem is that it allows replay attacks when somebody
* captures a packet sent to one server and sends it to another
* one. Should we add "AuthDigestNcCheck Strict"?
*/
#include "httpd.h"
#include "http_config.h"
#include "http_conf_globals.h"
#include "http_core.h"
#include "http_request.h"
#include "http_log.h"
#include "http_main.h"
#include "http_protocol.h"
#include "ap_config.h"
#include "ap_ctype.h"
#include "util_uri.h"
#include "util_md5.h"
#include "ap_sha1.h"
/* struct to hold the configuration info */
typedef struct digest_config_struct {
const char *dir_name;
const char *pwfile;
const char *grpfile;
const char *realm;
const char **qop_list;
AP_SHA1_CTX nonce_ctx;
long nonce_lifetime;
const char *nonce_format;
int check_nc;
const char *algorithm;
char *uri_list;
const char *ha1;
} digest_config_rec;
#define DFLT_ALGORITHM "MD5"
#define DFLT_NONCE_LIFE 300L
#define NEXTNONCE_DELTA 30
#define NONCE_TIME_LEN (((sizeof(time_t)+2)/3)*4)
#define NONCE_HASH_LEN (2*SHA_DIGESTSIZE)
#define NONCE_LEN (NONCE_TIME_LEN + NONCE_HASH_LEN)
#define SECRET_LEN 20
/* client list definitions */
typedef struct hash_entry {
unsigned long key; /* the key for this entry */
struct hash_entry *next; /* next entry in the bucket */
unsigned long nonce_count; /* for nonce-count checking */
char ha1[2*MD5_DIGESTSIZE+1]; /* for algorithm=MD5-sess */
char last_nonce[NONCE_LEN+1]; /* for one-time nonce's */
} client_entry;
static struct hash_table {
client_entry **table;
unsigned long tbl_len;
unsigned long num_entries;
unsigned long num_created;
unsigned long num_removed;
unsigned long num_renewed;
} *client_list;
/* struct to hold a parsed Authorization header */
enum hdr_sts { NO_HEADER, NOT_DIGEST, INVALID, VALID };
typedef struct digest_header_struct {
const char *scheme;
const char *realm;
const char *username;
char *nonce;
const char *uri;
const char *digest;
const char *algorithm;
const char *cnonce;
const char *opaque;
unsigned long opaque_num;
const char *message_qop;
const char *nonce_count;
/* the following fields are not (directly) from the header */
time_t nonce_time;
enum hdr_sts auth_hdr_sts;
const char *raw_request_uri;
uri_components *psd_request_uri;
int needed_auth;
client_entry *client;
} digest_header_rec;
/* (mostly) nonce stuff */
typedef union time_union {
time_t time;
unsigned char arr[sizeof(time_t)];
} time_rec;
static unsigned char secret[SECRET_LEN];
static int call_cnt = 0;
static void *client_mm = NULL;
module MODULE_VAR_EXPORT digest_auth_module;
/*
* initialization code
*/
static void initialize_secret(server_rec *s)
{
u_int32_t rnd = 0, i;
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, s,
"Digest: generating secret for digest authentication ...");
for (i = 0; i < sizeof(secret); i++) {
if (i % 4 == 0)
rnd = arc4random();
secret[i] = rnd;
rnd >>= 8;
}
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_NOTICE, s,
"Digest: done");
}
static void initialize_module(server_rec *s, pool *p)
{
/* keep from doing the init more than once at startup, and delay
* the init until the second round
*/
if (++call_cnt < 2)
return;
/* only initialize the secret on startup, not on restarts */
if (call_cnt == 2)
initialize_secret(s);
}
/*
* configuration code
*/
static void *create_digest_dir_config(pool *p, char *dir)
{
digest_config_rec *conf;
if (dir == NULL) return NULL;
conf = (digest_config_rec *) ap_pcalloc(p, sizeof(digest_config_rec));
if (conf) {
conf->qop_list = ap_palloc(p, sizeof(char*));
conf->qop_list[0] = NULL;
conf->nonce_lifetime = DFLT_NONCE_LIFE;
conf->dir_name = ap_pstrdup(p, dir);
conf->algorithm = DFLT_ALGORITHM;
}
return conf;
}
static const char *set_realm(cmd_parms *cmd, void *config, const char *realm)
{
digest_config_rec *conf = (digest_config_rec *) config;
/* The core already handles the realm, but it's just too convenient to
* grab it ourselves too and cache some setups. However, we need to
* let the core get at it too, which is why we decline at the end -
* this relies on the fact that http_core is last in the list.
*/
conf->realm = realm;
/* we precompute the part of the nonce hash that is constant (well,
* the host:port would be too, but that varies for .htaccess files
* and directives outside a virtual host section)
*/
ap_SHA1Init(&conf->nonce_ctx);
ap_SHA1Update_binary(&conf->nonce_ctx, secret, sizeof(secret));
ap_SHA1Update_binary(&conf->nonce_ctx, (const unsigned char *) realm,
strlen(realm));
return DECLINE_CMD;
}
static const char *set_digest_file(cmd_parms *cmd, void *config,
const char *file)
{
((digest_config_rec *) config)->pwfile = file;
ap_server_strip_chroot(((digest_config_rec *) config)->pwfile, 1);
return NULL;
}
static const char *set_group_file(cmd_parms *cmd, void *config,
const char *file)
{
((digest_config_rec *) config)->grpfile = file;
ap_server_strip_chroot(((digest_config_rec *) config)->grpfile, 1);
return NULL;
}
static const char *set_qop(cmd_parms *cmd, void *config, const char *op)
{
digest_config_rec *conf = (digest_config_rec *) config;
char **tmp;
int cnt;
if (!strcasecmp(op, "none")) {
if (conf->qop_list[0] == NULL) {
conf->qop_list = ap_palloc(cmd->pool, 2 * sizeof(char*));
conf->qop_list[1] = NULL;
}
conf->qop_list[0] = "none";
return NULL;
}
if (!strcasecmp(op, "auth-int"))
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, cmd->server,
"Digest: WARNING: qop `auth-int' currently only works "
"correctly for responses with no entity");
else if (strcasecmp(op, "auth"))
return ap_pstrcat(cmd->pool, "Unrecognized qop: ", op, NULL);
for (cnt=0; conf->qop_list[cnt] != NULL; cnt++)
;
tmp = ap_palloc(cmd->pool, (cnt+2)*sizeof(char*));
memcpy(tmp, conf->qop_list, cnt*sizeof(char*));
tmp[cnt] = ap_pstrdup(cmd->pool, op);
tmp[cnt+1] = NULL;
conf->qop_list = (const char **)tmp;
return NULL;
}
static const char *set_nonce_lifetime(cmd_parms *cmd, void *config,
const char *t)
{
char *endptr;
long lifetime;
lifetime = ap_strtol(t, &endptr, 10);
if (endptr < (t+strlen(t)) && !ap_isspace(*endptr))
return ap_pstrcat(cmd->pool, "Invalid time in AuthDigestNonceLifetime: ", t, NULL);
((digest_config_rec *) config)->nonce_lifetime = lifetime;
return NULL;
}
static const char *set_nonce_format(cmd_parms *cmd, void *config,
const char *fmt)
{
((digest_config_rec *) config)->nonce_format = fmt;
return "AuthDigestNonceFormat is not implemented (yet)";
}
static const char *set_nc_check(cmd_parms *cmd, void *config, int flag)
{
((digest_config_rec *) config)->check_nc = flag;
return NULL;
}
static const char *set_algorithm(cmd_parms *cmd, void *config, const char *alg)
{
if (!strcasecmp(alg, "MD5-sess"))
ap_log_error(APLOG_MARK, APLOG_NOERRNO|APLOG_WARNING, cmd->server,
"Digest: WARNING: algorithm `MD5-sess' is currently not "
"correctly implemented");
else if (strcasecmp(alg, "MD5"))
return ap_pstrcat(cmd->pool, "Invalid algorithm in AuthDigestAlgorithm: ", alg, NULL);
((digest_config_rec *) config)->algorithm = alg;
return NULL;
}
static const char *set_uri_list(cmd_parms *cmd, void *config, const char *uri)
{
digest_config_rec *c = (digest_config_rec *) config;
if (c->uri_list) {
c->uri_list[strlen(c->uri_list)-1] = '\0';
c->uri_list = ap_pstrcat(cmd->pool, c->uri_list, " ", uri, "\"", NULL);
}
else
c->uri_list = ap_pstrcat(cmd->pool, ", domain=\"", uri, "\"", NULL);
return NULL;
}
static const command_rec digest_cmds[] =
{
{"AuthName", set_realm, NULL, OR_AUTHCFG, TAKE1,
"The authentication realm (e.g. \"Members Only\")"},
{"AuthDigestFile", set_digest_file, NULL, OR_AUTHCFG, TAKE1,
"The name of the file containing the usernames and password hashes"},
{"AuthDigestGroupFile", set_group_file, NULL, OR_AUTHCFG, TAKE1,
"The name of the file containing the group names and members"},
{"AuthDigestQop", set_qop, NULL, OR_AUTHCFG, ITERATE,
"A list of quality-of-protection options"},
{"AuthDigestNonceLifetime", set_nonce_lifetime, NULL, OR_AUTHCFG, TAKE1,
"Maximum lifetime of the server nonce (seconds)"},
{"AuthDigestNonceFormat", set_nonce_format, NULL, OR_AUTHCFG, TAKE1,
"The format to use when generating the server nonce"},
{"AuthDigestNcCheck", set_nc_check, NULL, OR_AUTHCFG, FLAG,
"Whether or not to check the nonce-count sent by the client"},
{"AuthDigestAlgorithm", set_algorithm, NULL, OR_AUTHCFG, TAKE1,
"The algorithm used for the hash calculation"},
{"AuthDigestDomain", set_uri_list, NULL, OR_AUTHCFG, ITERATE,
"A list of URI's which belong to the same protection space as the current URI"},
{NULL, NULL, NULL, 0, 0, NULL}
};
static client_entry *get_client(unsigned long key, const request_rec *r)
{
return NULL;
}
/*
* Authorization header parser code
*/
/* Parse the Authorization header, if it exists */
static int get_digest_rec(request_rec *r, digest_header_rec *resp)
{
const char *auth_line;
size_t l;
int vk = 0, vv = 0;
char *key, *value;
auth_line = ap_table_get(r->headers_in,
r->proxyreq == STD_PROXY ? "Proxy-Authorization"
: "Authorization");
if (!auth_line) {
resp->auth_hdr_sts = NO_HEADER;
return !OK;
}
resp->scheme = ap_getword_white(r->pool, &auth_line);
if (strcasecmp(resp->scheme, "Digest")) {
resp->auth_hdr_sts = NOT_DIGEST;
return !OK;
}
l = strlen(auth_line);
key = ap_palloc(r->pool, l+1);
value = ap_palloc(r->pool, l+1);
while (auth_line[0] != '\0') {
/* find key */
while (ap_isspace(auth_line[0])) auth_line++;
vk = 0;
while (auth_line[0] != '=' && auth_line[0] != ','
&& auth_line[0] != '\0' && !ap_isspace(auth_line[0]))
key[vk++] = *auth_line++;
key[vk] = '\0';
while (ap_isspace(auth_line[0])) auth_line++;
/* find value */
if (auth_line[0] == '=') {
auth_line++;
while (ap_isspace(auth_line[0])) auth_line++;
vv = 0;
if (auth_line[0] == '\"') { /* quoted string */
auth_line++;
while (auth_line[0] != '\"' && auth_line[0] != '\0') {
if (auth_line[0] == '\\' && auth_line[1] != '\0')
auth_line++; /* escaped char */
value[vv++] = *auth_line++;
}
if (auth_line[0] != '\0') auth_line++;
}
else { /* token */
while (auth_line[0] != ',' && auth_line[0] != '\0'
&& !ap_isspace(auth_line[0]))
value[vv++] = *auth_line++;
}
value[vv] = '\0';
}
while (auth_line[0] != ',' && auth_line[0] != '\0') auth_line++;
if (auth_line[0] != '\0') auth_line++;
if (!strcasecmp(key, "username"))
resp->username = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "realm"))
resp->realm = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "nonce"))
resp->nonce = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "uri"))
resp->uri = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "response"))
resp->digest = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "algorithm"))
resp->algorithm = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "cnonce"))
resp->cnonce = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "opaque"))
resp->opaque = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "qop"))
resp->message_qop = ap_pstrdup(r->pool, value);
else if (!strcasecmp(key, "nc"))
resp->nonce_count = ap_pstrdup(r->pool, value);
}
if (!resp->username || !resp->realm || !resp->nonce || !resp->uri
|| !resp->digest
|| (resp->message_qop && (!resp->cnonce || !resp->nonce_count))) {
resp->auth_hdr_sts = INVALID;
return !OK;
}
if (resp->opaque)
resp->opaque_num = (unsigned long) ap_strtol(resp->opaque, NULL, 16);
resp->auth_hdr_sts = VALID;
return OK;
}
/* Because the browser may preemptively send auth info, incrementing the
* nonce-count when it does, and because the client does not get notified
* if the URI didn't need authentication after all, we need to be sure to
* update the nonce-count each time we receive an Authorization header no
* matter what the final outcome of the request. Furthermore this is a
* convenient place to get the request-uri (before any subrequests etc
* are initiated) and to initialize the request_config.
*
* Note that this must be called after mod_proxy had its go so that
* r->proxyreq is set correctly.
*/
static int update_nonce_count(request_rec *r)
{
digest_header_rec *resp;
int res;
if (!ap_is_initial_req(r))
return DECLINED;
resp = ap_pcalloc(r->pool, sizeof(digest_header_rec));
resp->raw_request_uri = r->unparsed_uri;
resp->psd_request_uri = &r->parsed_uri;
resp->needed_auth = 0;
ap_set_module_config(r->request_config, &digest_auth_module, resp);
res = get_digest_rec(r, resp);
resp->client = get_client(resp->opaque_num, r);
if (res == OK && resp->client)
resp->client->nonce_count++;
return DECLINED;
}
/*
* Nonce generation code
*/
/* The hash part of the nonce is a SHA-1 hash of the time, realm, server host
* and port, opaque, and our secret.
*/
static void gen_nonce_hash(char *hash, const char *timestr, const char *opaque,
const server_rec *server,
const digest_config_rec *conf)
{
const char *hex = "0123456789abcdef";
unsigned char sha1[SHA_DIGESTSIZE];
AP_SHA1_CTX ctx;
int idx;
memcpy(&ctx, &conf->nonce_ctx, sizeof(ctx));
/*
ap_SHA1Update_binary(&ctx, (const unsigned char *) server->server_hostname,
strlen(server->server_hostname));
ap_SHA1Update_binary(&ctx, (const unsigned char *) &server->port,
sizeof(server->port));
*/
ap_SHA1Update_binary(&ctx, (const unsigned char *) timestr, strlen(timestr));
if (opaque)
ap_SHA1Update_binary(&ctx, (const unsigned char *) opaque,
strlen(opaque));
ap_SHA1Final(sha1, &ctx);
for (idx=0; idx> 4];
*hash++ = hex[sha1[idx] & 0xF];
}
*hash++ = '\0';
}
/* The nonce has the format b64(time)+hash .
*/
static const char *gen_nonce(pool *p, time_t now, const char *opaque,
const server_rec *server,
const digest_config_rec *conf)
{
char *nonce = ap_palloc(p, NONCE_LEN+1);
time_rec t;
if (conf->nonce_lifetime != 0)
t.time = now;
else
t.time = 42;
ap_base64encode_binary(nonce, t.arr, sizeof(t.arr));
gen_nonce_hash(nonce+NONCE_TIME_LEN, nonce, opaque, server, conf);
return nonce;
}
/*
* Opaque and hash-table management
*/
static client_entry *gen_client(const request_rec *r) { return NULL; }
/*
* MD5-sess code.
*
* If you want to use algorithm=MD5-sess you must write get_userpw_hash()
* yourself (see below). The dummy provided here just uses the hash from
* the auth-file, i.e. it is only useful for testing client implementations
* of MD5-sess .
*/
/*
* get_userpw_hash() will be called each time a new session needs to be
* generated and is expected to return the equivalent of
*
* h_urp = ap_md5(r->pool,
* ap_pstrcat(r->pool, username, ":", ap_auth_name(r), ":", passwd))
* ap_md5(r->pool,
* (unsigned char *) ap_pstrcat(r->pool, h_urp, ":", resp->nonce, ":",
* resp->cnonce, NULL));
*
* or put differently, it must return
*
* MD5(MD5(username ":" realm ":" password) ":" nonce ":" cnonce)
*
* If something goes wrong, the failure must be logged and NULL returned.
*
* You must implement this yourself, which will probably consist of code
* contacting the password server with the necessary information (typically
* the username, realm, nonce, and cnonce) and receiving the hash from it.
*
* TBD: This function should probably be in a seperate source file so that
* people need not modify mod_auth_digest.c each time they install a new
* version of apache.
*/
static const char *get_userpw_hash(const request_rec *r,
const digest_header_rec *resp,
const digest_config_rec *conf)
{
return ap_md5(r->pool,
(unsigned char *) ap_pstrcat(r->pool, conf->ha1, ":", resp->nonce,
":", resp->cnonce, NULL));
}
/* Retrieve current session H(A1). If there is none and "generate" is
* true then a new session for MD5-sess is generated and stored in the
* client struct; if generate is false, or a new session could not be
* generated then NULL is returned (in case of failure to generate the
* failure reason will have been logged already).
*/
static const char *get_session_HA1(const request_rec *r,
digest_header_rec *resp,
const digest_config_rec *conf,
int generate)
{
const char *ha1 = NULL;
/* return the current sessions if there is one */
if (resp->opaque && resp->client && resp->client->ha1[0])
return resp->client->ha1;
else if (!generate)
return NULL;
/* generate a new session */
if (!resp->client)
resp->client = gen_client(r);
if (resp->client) {
ha1 = get_userpw_hash(r, resp, conf);
if (ha1)
memcpy(resp->client->ha1, ha1, sizeof(resp->client->ha1));
}
return ha1;
}
static void clear_session(const digest_header_rec *resp)
{
if (resp->client)
resp->client->ha1[0] = '\0';
}
/*
* Authorization challenge generation code (for WWW-Authenticate)
*/
static const char *ltox(pool *p, unsigned long num)
{
if (num != 0)
return ap_psprintf(p, "%lx", num);
else
return "";
}
static void note_digest_auth_failure(request_rec *r,
const digest_config_rec *conf,
digest_header_rec *resp, int stale)
{
const char *qop, *opaque, *opaque_param, *domain, *nonce;
int cnt;
/* Setup qop */
if (conf->qop_list[0] == NULL)
qop = ", qop=\"auth\"";
else if (!strcasecmp(conf->qop_list[0], "none"))
qop = "";
else {
qop = ap_pstrcat(r->pool, ", qop=\"", conf->qop_list[0], NULL);
for (cnt=1; conf->qop_list[cnt] != NULL; cnt++)
qop = ap_pstrcat(r->pool, qop, ",", conf->qop_list[cnt], NULL);
qop = ap_pstrcat(r->pool, qop, "\"", NULL);
}
/* Setup opaque */
if (resp->opaque == NULL) {
/* new client */
if ((conf->check_nc || conf->nonce_lifetime == 0
|| !strcasecmp(conf->algorithm, "MD5-sess"))
&& (resp->client = gen_client(r)) != NULL)
opaque = ltox(r->pool, resp->client->key);
else
opaque = ""; /* opaque not needed */
}
else if (resp->client == NULL) {
/* client info was gc'd */
resp->client = gen_client(r);
if (resp->client != NULL) {
opaque = ltox(r->pool, resp->client->key);
stale = 1;
client_list->num_renewed++;
}
else
opaque = ""; /* ??? */
}
else {
opaque = resp->opaque;
/* we're generating a new nonce, so reset the nonce-count */
resp->client->nonce_count = 0;
}
if (opaque[0])
opaque_param = ap_pstrcat(r->pool, ", opaque=\"", opaque, "\"", NULL);
else
opaque_param = NULL;
/* Setup nonce */
nonce = gen_nonce(r->pool, r->request_time, opaque, r->server, conf);
if (resp->client && conf->nonce_lifetime == 0)
memcpy(resp->client->last_nonce, nonce, NONCE_LEN+1);
/* Setup MD5-sess stuff. Note that we just clear out the session
* info here, since we can't generate a new session until the request
* from the client comes in with the cnonce.
*/
if (!strcasecmp(conf->algorithm, "MD5-sess"))
clear_session(resp);
/* setup domain attribute. We want to send this attribute wherever
* possible so that the client won't send the Authorization header
* unnecessarily (it's usually > 200 bytes!).
*/
/* don't send domain
* - for proxy requests
* - if it's no specified
*/
if (r->proxyreq || !conf->uri_list) {
domain = NULL;
}
else {
domain = conf->uri_list;
}
ap_table_mergen(r->err_headers_out,
r->proxyreq == STD_PROXY ? "Proxy-Authenticate"
: "WWW-Authenticate",
ap_psprintf(r->pool, "Digest realm=\"%s\", nonce=\"%s\", "
"algorithm=%s%s%s%s%s",
ap_auth_name(r), nonce, conf->algorithm,
opaque_param ? opaque_param : "",
domain ? domain : "",
stale ? ", stale=true" : "", qop));
}
/*
* Authorization header verification code
*/
static const char *get_hash(request_rec *r, const char *user,
const char *realm, const char *auth_pwfile)
{
configfile_t *f;
char l[MAX_STRING_LEN];
const char *rpw;
char *w, *x;
if (!(f = ap_pcfg_openfile(r->pool, auth_pwfile))) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
"Digest: Could not open password file: %s", auth_pwfile);
return NULL;
}
while (!(ap_cfg_getline(l, MAX_STRING_LEN, f))) {
if ((l[0] == '#') || (!l[0]))
continue;
rpw = l;
w = ap_getword(r->pool, &rpw, ':');
x = ap_getword(r->pool, &rpw, ':');
if (x && w && !strcmp(user, w) && !strcmp(realm, x)) {
ap_cfg_closefile(f);
return ap_pstrdup(r->pool, rpw);
}
}
ap_cfg_closefile(f);
return NULL;
}
static int check_nc(const request_rec *r, const digest_header_rec *resp,
const digest_config_rec *conf)
{
unsigned long nc;
const char *snc = resp->nonce_count;
char *endptr;
if (!conf->check_nc || !client_mm)
return OK;
nc = ap_strtol(snc, &endptr, 16);
if (endptr < (snc+strlen(snc)) && !ap_isspace(*endptr)) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: invalid nc %s received - not a number", snc);
return !OK;
}
if (!resp->client)
return !OK;
if (nc != resp->client->nonce_count) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: Warning, possible replay attack: nonce-count "
"check failed: %lu != %lu", nc,
resp->client->nonce_count);
return !OK;
}
return OK;
}
static int check_nonce(request_rec *r, digest_header_rec *resp,
const digest_config_rec *conf)
{
double dt;
time_rec nonce_time;
char tmp, hash[NONCE_HASH_LEN+1];
if (strlen(resp->nonce) != NONCE_LEN) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: invalid nonce %s received - length is not %d",
resp->nonce, NONCE_LEN);
note_digest_auth_failure(r, conf, resp, 1);
return AUTH_REQUIRED;
}
tmp = resp->nonce[NONCE_TIME_LEN];
resp->nonce[NONCE_TIME_LEN] = '\0';
ap_base64decode_binary(nonce_time.arr, resp->nonce);
gen_nonce_hash(hash, resp->nonce, resp->opaque, r->server, conf);
resp->nonce[NONCE_TIME_LEN] = tmp;
resp->nonce_time = nonce_time.time;
if (strcmp(hash, resp->nonce+NONCE_TIME_LEN)) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: invalid nonce %s received - hash is not %s",
resp->nonce, hash);
note_digest_auth_failure(r, conf, resp, 1);
return AUTH_REQUIRED;
}
dt = difftime(r->request_time, nonce_time.time);
if (conf->nonce_lifetime > 0 && dt < 0) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: invalid nonce %s received - user attempted "
"time travel", resp->nonce);
note_digest_auth_failure(r, conf, resp, 1);
return AUTH_REQUIRED;
}
if (conf->nonce_lifetime > 0) {
if (dt > conf->nonce_lifetime) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, r,
"Digest: user %s: nonce expired - sending new nonce",
r->connection->user);
note_digest_auth_failure(r, conf, resp, 1);
return AUTH_REQUIRED;
}
}
else if (conf->nonce_lifetime == 0 && resp->client) {
if (memcmp(resp->client->last_nonce, resp->nonce, NONCE_LEN)) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_INFO, r,
"Digest: user %s: one-time-nonce mismatch - sending "
"new nonce", r->connection->user);
note_digest_auth_failure(r, conf, resp, 1);
return AUTH_REQUIRED;
}
}
/* else (lifetime < 0) => never expires */
return OK;
}
/* The actual MD5 code... whee */
/* RFC-2069 */
static const char *old_digest(const request_rec *r,
const digest_header_rec *resp, const char *ha1)
{
const char *ha2;
ha2 = ap_md5(r->pool, (unsigned char *)ap_pstrcat(r->pool, r->method, ":",
resp->uri, NULL));
return ap_md5(r->pool,
(unsigned char *)ap_pstrcat(r->pool, ha1, ":", resp->nonce,
":", ha2, NULL));
}
/* RFC-2617 */
static const char *new_digest(const request_rec *r,
digest_header_rec *resp,
const digest_config_rec *conf)
{
const char *ha1, *ha2, *a2;
if (resp->algorithm && !strcasecmp(resp->algorithm, "MD5-sess")) {
ha1 = get_session_HA1(r, resp, conf, 1);
if (!ha1)
return NULL;
}
else
ha1 = conf->ha1;
if (resp->message_qop && !strcasecmp(resp->message_qop, "auth-int"))
a2 = ap_pstrcat(r->pool, r->method, ":", resp->uri, ":",
ap_md5(r->pool, (const unsigned char*) ""), NULL); /* TBD */
else
a2 = ap_pstrcat(r->pool, r->method, ":", resp->uri, NULL);
ha2 = ap_md5(r->pool, (const unsigned char *)a2);
return ap_md5(r->pool,
(unsigned char *)ap_pstrcat(r->pool, ha1, ":", resp->nonce,
":", resp->nonce_count, ":",
resp->cnonce, ":",
resp->message_qop, ":", ha2,
NULL));
}
static void copy_uri_components(uri_components *dst, uri_components *src,
request_rec *r)
{
if (src->scheme && src->scheme[0] != '\0')
dst->scheme = src->scheme;
else
dst->scheme = (char *) "http";
if (src->hostname && src->hostname[0] != '\0') {
dst->hostname = ap_pstrdup(r->pool, src->hostname);
ap_unescape_url(dst->hostname);
}
else
dst->hostname = (char *) ap_get_server_name(r);
if (src->port_str && src->port_str[0] != '\0')
dst->port = src->port;
else
dst->port = ap_get_server_port(r);
if (src->path && src->path[0] != '\0') {
dst->path = ap_pstrdup(r->pool, src->path);
ap_unescape_url(dst->path);
}
else
dst->path = src->path;
if (src->query && src->query[0] != '\0') {
dst->query = ap_pstrdup(r->pool, src->query);
ap_unescape_url(dst->query);
}
else
dst->query = src->query;
}
/* This handles non-FQDN's. If h1 is empty, the comparison succeeds. Else
* if h1 is a FQDN (i.e. contains a '.') then normal strcasecmp() is done.
* Else only the first part of h2 (up to the first '.') is compared.
*/
static int compare_hostnames(const char *h1, const char *h2)
{
const char *dot;
/* if no hostname given, then ok */
if (!h1 || h1[0] == '\0')
return 1;
/* handle FQDN's in h1 */
dot = strchr(h1, '.');
if (dot != NULL)
return !strcasecmp(h1, h2);
/* handle non-FQDN's in h1 */
dot = strchr(h2, '.');
if (dot == NULL)
return !strcasecmp(h1, h2);
else
return (strlen(h1) == (size_t) (dot - h2)) && !strncasecmp(h1, h2, dot-h2);
}
/* These functions return 0 if client is OK, and proper error status
* if not... either AUTH_REQUIRED, if we made a check, and it failed, or
* SERVER_ERROR, if things are so totally confused that we couldn't
* figure out how to tell if the client is authorized or not.
*
* If they return DECLINED, and all other modules also decline, that's
* treated by the server core as a configuration error, logged and
* reported as such.
*/
/* Determine user ID, and check if the attributes are correct, if it
* really is that user, if the nonce is correct, etc.
*/
static int authenticate_digest_user(request_rec *r)
{
digest_config_rec *conf;
digest_header_rec *resp;
request_rec *mainreq;
conn_rec *conn = r->connection;
const char *t;
int res;
/* do we require Digest auth for this URI? */
if (!(t = ap_auth_type(r)) || strcasecmp(t, "Digest"))
return DECLINED;
if (!ap_auth_name(r)) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: need AuthName: %s", r->uri);
return SERVER_ERROR;
}
/* get the client response and mark */
mainreq = r;
while (mainreq->main != NULL) mainreq = mainreq->main;
while (mainreq->prev != NULL) mainreq = mainreq->prev;
resp = (digest_header_rec *) ap_get_module_config(mainreq->request_config,
&digest_auth_module);
resp->needed_auth = 1;
/* get our conf */
conf = (digest_config_rec *) ap_get_module_config(r->per_dir_config,
&digest_auth_module);
/* check for existence and syntax of Auth header */
if (resp->auth_hdr_sts != VALID) {
if (resp->auth_hdr_sts == NOT_DIGEST)
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: client used wrong authentication scheme "
"`%s': %s", resp->scheme, r->uri);
else if (resp->auth_hdr_sts == INVALID)
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: missing user, realm, nonce, uri, digest, "
"cnonce, or nonce_count in authorization header: %s",
r->uri);
/* else (resp->auth_hdr_sts == NO_HEADER) */
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
r->connection->user = (char *) resp->username;
r->connection->ap_auth_type = (char *) "Digest";
/* check the auth attributes */
if (strcmp(resp->uri, resp->raw_request_uri)) {
/* Hmm, the simple match didn't work (probably a proxy modified the
* request-uri), so lets do a more sophisticated match
*/
uri_components r_uri, d_uri;
copy_uri_components(&r_uri, resp->psd_request_uri, r);
if (ap_parse_uri_components(r->pool, resp->uri, &d_uri) != HTTP_OK) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: invalid uri <%s> in Authorization header",
resp->uri);
return BAD_REQUEST;
}
if (d_uri.hostname)
ap_unescape_url(d_uri.hostname);
if (d_uri.path)
ap_unescape_url(d_uri.path);
if (d_uri.query)
ap_unescape_url(d_uri.query);
if (r->method_number == M_CONNECT) {
if (strcmp(resp->uri, r_uri.hostinfo)) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: uri mismatch - <%s> does not match "
"request-uri <%s>", resp->uri, r_uri.hostinfo);
return BAD_REQUEST;
}
}
else if (
/* check hostname matches, if present */
!compare_hostnames(d_uri.hostname, r_uri.hostname)
/* check port matches, if present */
|| (d_uri.port_str && d_uri.port != r_uri.port)
/* check that server-port is default port if no port present */
|| (d_uri.hostname && d_uri.hostname[0] != '\0'
&& !d_uri.port_str && r_uri.port != ap_default_port(r))
/* check that path matches */
|| (d_uri.path != r_uri.path
/* either exact match */
&& (!d_uri.path || !r_uri.path
|| strcmp(d_uri.path, r_uri.path))
/* or '*' matches empty path in scheme://host */
&& !(d_uri.path && !r_uri.path && resp->psd_request_uri->hostname
&& d_uri.path[0] == '*' && d_uri.path[1] == '\0'))
) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: uri mismatch - <%s> does not match "
"request-uri <%s>", resp->uri, resp->raw_request_uri);
return BAD_REQUEST;
}
}
if (resp->opaque && resp->opaque_num == 0) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: received invalid opaque - got `%s'",
resp->opaque);
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
if (strcmp(resp->realm, conf->realm)) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: realm mismatch - got `%s' but expected `%s'",
resp->realm, conf->realm);
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
if (resp->algorithm != NULL
&& strcasecmp(resp->algorithm, "MD5")
&& strcasecmp(resp->algorithm, "MD5-sess")) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: unknown algorithm `%s' received: %s",
resp->algorithm, r->uri);
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
if (!conf->pwfile)
return DECLINED;
if (!(conf->ha1 = get_hash(r, conn->user, conf->realm, conf->pwfile))) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: user `%s' in realm `%s' not found: %s",
conn->user, conf->realm, r->uri);
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
if (resp->message_qop == NULL) {
/* old (rfc-2069) style digest */
if (strcmp(resp->digest, old_digest(r, resp, conf->ha1))) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: user %s: password mismatch: %s", conn->user,
r->uri);
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
}
else {
const char *exp_digest;
int match = 0, idx;
for (idx=0; conf->qop_list[idx] != NULL; idx++) {
if (!strcasecmp(conf->qop_list[idx], resp->message_qop)) {
match = 1;
break;
}
}
if (!match
&& !(conf->qop_list[0] == NULL
&& !strcasecmp(resp->message_qop, "auth"))) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: invalid qop `%s' received: %s",
resp->message_qop, r->uri);
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
if (check_nc(r, resp, conf) != OK) {
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
exp_digest = new_digest(r, resp, conf);
if (!exp_digest) {
/* we failed to allocate a client struct */
return SERVER_ERROR;
}
if (strcmp(resp->digest, exp_digest)) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: user %s: password mismatch: %s", conn->user,
r->uri);
note_digest_auth_failure(r, conf, resp, 0);
return AUTH_REQUIRED;
}
}
/* Note: this check is done last so that a "stale=true" can be
generated if the nonce is old */
if ((res = check_nonce(r, resp, conf)))
return res;
return OK;
}
/*
* Checking ID
*/
static table *groups_for_user(request_rec *r, const char *user,
const char *grpfile)
{
configfile_t *f;
table *grps = ap_make_table(r->pool, 15);
pool *sp;
char l[MAX_STRING_LEN];
const char *group_name, *ll, *w;
if (!(f = ap_pcfg_openfile(r->pool, grpfile))) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
"Digest: Could not open group file: %s", grpfile);
return NULL;
}
sp = ap_make_sub_pool(r->pool);
while (!(ap_cfg_getline(l, MAX_STRING_LEN, f))) {
if ((l[0] == '#') || (!l[0]))
continue;
ll = l;
ap_clear_pool(sp);
group_name = ap_getword(sp, &ll, ':');
while (ll[0]) {
w = ap_getword_conf(sp, &ll);
if (!strcmp(w, user)) {
ap_table_setn(grps, ap_pstrdup(r->pool, group_name), "in");
break;
}
}
}
ap_cfg_closefile(f);
ap_destroy_pool(sp);
return grps;
}
static int digest_check_auth(request_rec *r)
{
const digest_config_rec *conf =
(digest_config_rec *) ap_get_module_config(r->per_dir_config,
&digest_auth_module);
const char *user = r->connection->user;
int m = r->method_number;
int method_restricted = 0;
int x;
const char *t, *w;
table *grpstatus;
const array_header *reqs_arr;
require_line *reqs;
if (!(t = ap_auth_type(r)) || strcasecmp(t, "Digest"))
return DECLINED;
reqs_arr = ap_requires(r);
/* If there is no "requires" directive, then any user will do.
*/
if (!reqs_arr)
return OK;
reqs = (require_line *) reqs_arr->elts;
if (conf->grpfile)
grpstatus = groups_for_user(r, user, conf->grpfile);
else
grpstatus = NULL;
for (x = 0; x < reqs_arr->nelts; x++) {
if (!(reqs[x].method_mask & (1 << m)))
continue;
method_restricted = 1;
t = reqs[x].requirement;
w = ap_getword_white(r->pool, &t);
if (!strcasecmp(w, "valid-user"))
return OK;
else if (!strcasecmp(w, "user")) {
while (t[0]) {
w = ap_getword_conf(r->pool, &t);
if (!strcmp(user, w))
return OK;
}
}
else if (!strcasecmp(w, "group")) {
if (!grpstatus)
return DECLINED;
while (t[0]) {
w = ap_getword_conf(r->pool, &t);
if (ap_table_get(grpstatus, w))
return OK;
}
}
else {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: access to %s failed, reason: unknown require "
"directive \"%s\"", r->uri, reqs[x].requirement);
return DECLINED;
}
}
if (!method_restricted)
return OK;
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: access to %s failed, reason: user %s not allowed access",
r->uri, user);
note_digest_auth_failure(r, conf,
(digest_header_rec *) ap_get_module_config(r->request_config,
&digest_auth_module),
0);
return AUTH_REQUIRED;
}
/*
* Authorization-Info header code
*/
static int add_auth_info(request_rec *r)
{
const digest_config_rec *conf =
(digest_config_rec *) ap_get_module_config(r->per_dir_config,
&digest_auth_module);
digest_header_rec *resp =
(digest_header_rec *) ap_get_module_config(r->request_config,
&digest_auth_module);
const char *ai = NULL, *digest = NULL, *nextnonce = "";
if (resp == NULL || !resp->needed_auth || conf == NULL)
return OK;
/* rfc-2069 digest
*/
if (resp->message_qop == NULL) {
/* old client, so calc rfc-2069 digest */
}
/* setup nextnonce
*/
if (conf->nonce_lifetime > 0) {
/* send nextnonce if current nonce will expire in less than 30 secs */
if (difftime(r->request_time, resp->nonce_time) > (conf->nonce_lifetime-NEXTNONCE_DELTA)) {
nextnonce = ap_pstrcat(r->pool, ", nextnonce=\"",
gen_nonce(r->pool, r->request_time,
resp->opaque, r->server, conf),
"\"", NULL);
if (resp->client)
resp->client->nonce_count = 0;
}
}
else if (conf->nonce_lifetime == 0 && resp->client) {
const char *nonce = gen_nonce(r->pool, 0, resp->opaque, r->server,
conf);
nextnonce = ap_pstrcat(r->pool, ", nextnonce=\"", nonce, "\"", NULL);
memcpy(resp->client->last_nonce, nonce, NONCE_LEN+1);
}
/* else nonce never expires, hence no nextnonce */
/* do rfc-2069 digest
*/
if (conf->qop_list[0] && !strcasecmp(conf->qop_list[0], "none")
&& resp->message_qop == NULL) {
/* use only RFC-2069 format */
if (digest)
ai = ap_pstrcat(r->pool, "digest=\"", digest, "\"", nextnonce,NULL);
else
ai = nextnonce;
}
else {
const char *resp_dig, *ha1, *a2, *ha2;
/* calculate rspauth attribute
*/
if (resp->algorithm && !strcasecmp(resp->algorithm, "MD5-sess")) {
ha1 = get_session_HA1(r, resp, conf, 0);
if (!ha1) {
ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
"Digest: internal error: couldn't find session "
"info for user %s", resp->username);
return !OK;
}
}
else
ha1 = conf->ha1;
if (resp->message_qop && !strcasecmp(resp->message_qop, "auth-int"))
a2 = ap_pstrcat(r->pool, ":", resp->uri, ":",
ap_md5(r->pool, (const unsigned char *) ""), NULL); /* TBD */
else
a2 = ap_pstrcat(r->pool, ":", resp->uri, NULL);
ha2 = ap_md5(r->pool, (const unsigned char *)a2);
resp_dig = ap_md5(r->pool,
(unsigned char *)ap_pstrcat(r->pool, ha1, ":",
resp->nonce, ":",
resp->nonce_count, ":",
resp->cnonce, ":",
resp->message_qop ?
resp->message_qop : "",
":", ha2, NULL));
/* assemble Authentication-Info header
*/
ai = ap_pstrcat(r->pool,
"rspauth=\"", resp_dig, "\"",
nextnonce,
resp->cnonce ? ", cnonce=\"" : "",
resp->cnonce ? ap_escape_quotes(r->pool, resp->cnonce) :
"",
resp->cnonce ? "\"" : "",
resp->nonce_count ? ", nc=" : "",
resp->nonce_count ? resp->nonce_count : "",
resp->message_qop ? ", qop=" : "",
resp->message_qop ? resp->message_qop : "",
digest ? "digest=\"" : "",
digest ? digest : "",
digest ? "\"" : "",
NULL);
}
if (ai && ai[0])
ap_table_mergen(r->headers_out,
r->proxyreq == STD_PROXY ? "Proxy-Authentication-Info"
: "Authentication-Info",
ai);
return OK;
}
module MODULE_VAR_EXPORT digest_auth_module =
{
STANDARD_MODULE_STUFF,
initialize_module, /* initializer */
create_digest_dir_config, /* dir config creater */
NULL, /* dir merger --- default is to override */
NULL, /* server config */
NULL, /* merge server config */
digest_cmds, /* command table */
NULL, /* handlers */
NULL, /* filename translation */
authenticate_digest_user, /* check_user_id */
digest_check_auth, /* check auth */
NULL, /* check access */
NULL, /* type_checker */
add_auth_info, /* fixups */
NULL, /* logger */
NULL, /* header parser */
NULL, /* child_init */
NULL, /* child_exit */
update_nonce_count /* post read-request */
};