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ngx_http_auth_spnego_module.c
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/*
* Copyright (C) 2009 Michal Kowalski <superflouos{at}gmail[dot]com>
* Copyright (C) 2012-2013 Sean Timothy Noonan <[email protected]>
* Copyright (C) 2013 Marcello Barnaba <[email protected]>
* Copyright (C) 2013 Alexander Pyhalov <[email protected]>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <gssapi/gssapi.h>
#include <gssapi/gssapi_krb5.h>
#include <krb5.h>
#include <stdbool.h>
#define CCACHE_VARIABLE_NAME "krb5_cc_name"
#define SHM_ZONE_NAME "shm_zone"
#define RENEWAL_TIME 60
#define discard_const(ptr) ((void *)((uintptr_t)(ptr)))
#define spnego_log_krb5_error(context, code) \
{ \
const char *___kerror = krb5_get_error_message(context, code); \
spnego_debug2("Kerberos error: %d, %s", code, ___kerror); \
krb5_free_error_message(context, ___kerror); \
}
#define spnego_error(code) \
ret = code; \
goto end
#define spnego_debug0(msg) \
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, msg)
#define spnego_debug1(msg, one) \
ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, msg, one)
#define spnego_debug2(msg, one, two) \
ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, msg, one, two)
#define spnego_debug3(msg, one, two, three) \
ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, msg, one, two, \
three)
#define spnego_log_error(fmt, args...) \
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, fmt, ##args)
#ifndef krb5_realm_length
#define krb5_realm_length(r) ((r).length)
#define krb5_realm_data(r) ((r).data)
#endif
/* Module handler */
static ngx_int_t ngx_http_auth_spnego_handler(ngx_http_request_t *);
static void *ngx_http_auth_spnego_create_loc_conf(ngx_conf_t *);
static char *ngx_http_auth_spnego_merge_loc_conf(ngx_conf_t *, void *, void *);
static ngx_int_t ngx_http_auth_spnego_init(ngx_conf_t *);
#if (NGX_PCRE)
static char *ngx_conf_set_regex_array_slot(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf);
#endif
ngx_int_t ngx_http_auth_spnego_set_bogus_authorization(ngx_http_request_t *r);
const char *get_gss_error(ngx_pool_t *p, OM_uint32 error_status, char *prefix) {
OM_uint32 maj_stat, min_stat;
OM_uint32 msg_ctx = 0;
gss_buffer_desc status_string;
char buf[1024];
size_t len;
ngx_str_t str;
ngx_snprintf((u_char *)buf, sizeof(buf), "%s: %Z", prefix);
len = ngx_strlen(buf);
do {
maj_stat = gss_display_status(&min_stat, error_status, GSS_C_MECH_CODE,
GSS_C_NO_OID, &msg_ctx, &status_string);
if (sizeof(buf) > len + status_string.length + 1) {
ngx_sprintf((u_char *)buf + len, "%s:%Z",
(char *)status_string.value);
len += (status_string.length + 1);
}
gss_release_buffer(&min_stat, &status_string);
} while (!GSS_ERROR(maj_stat) && msg_ctx != 0);
str.len = len + 1; /* "include" '\0' */
str.data = (u_char *)buf;
return (char *)(ngx_pstrdup(p, &str));
}
static ngx_shm_zone_t *shm_zone;
typedef enum { TYPE_KRB5_CREDS, TYPE_GSS_CRED_ID_T } creds_type;
typedef struct {
void *data;
creds_type type;
} creds_info;
/* per request/connection */
typedef struct {
ngx_str_t token; /* decoded Negotiate token */
ngx_int_t head; /* non-zero flag if headers set */
ngx_int_t ret; /* current return code */
ngx_str_t token_out_b64; /* base64 encoded output tokent */
} ngx_http_auth_spnego_ctx_t;
typedef struct {
ngx_flag_t protect;
ngx_str_t realm;
ngx_str_t keytab;
ngx_str_t service_ccache;
ngx_str_t srvcname;
ngx_flag_t fqun;
ngx_flag_t force_realm;
ngx_flag_t allow_basic;
ngx_array_t *auth_princs;
#if (NGX_PCRE)
ngx_array_t *auth_princs_regex;
#endif
ngx_flag_t map_to_local;
ngx_flag_t delegate_credentials;
ngx_flag_t constrained_delegation;
} ngx_http_auth_spnego_loc_conf_t;
#define SPNEGO_NGX_CONF_FLAGS \
NGX_HTTP_MAIN_CONF \
| NGX_HTTP_SRV_CONF | NGX_HTTP_LOC_CONF | NGX_HTTP_LMT_CONF | NGX_CONF_FLAG
/* Module Directives */
static ngx_command_t ngx_http_auth_spnego_commands[] = {
{ngx_string("auth_gss"), SPNEGO_NGX_CONF_FLAGS, ngx_conf_set_flag_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, protect), NULL},
{ngx_string("auth_gss_realm"), SPNEGO_NGX_CONF_FLAGS, ngx_conf_set_str_slot,
NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_auth_spnego_loc_conf_t, realm),
NULL},
{ngx_string("auth_gss_keytab"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_str_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, keytab), NULL},
{ngx_string("auth_gss_service_ccache"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_str_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, service_ccache), NULL},
{ngx_string("auth_gss_service_name"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_str_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, srvcname), NULL},
{ngx_string("auth_gss_format_full"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, fqun), NULL},
{ngx_string("auth_gss_force_realm"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, force_realm), NULL},
{ngx_string("auth_gss_allow_basic_fallback"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, allow_basic), NULL},
{ngx_string("auth_gss_authorized_principal"),
SPNEGO_NGX_CONF_FLAGS | NGX_CONF_1MORE, ngx_conf_set_str_array_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, auth_princs), NULL},
#if (NGX_PCRE)
{ngx_string("auth_gss_authorized_principal_regex"),
SPNEGO_NGX_CONF_FLAGS | NGX_CONF_1MORE, ngx_conf_set_regex_array_slot,
NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, auth_princs_regex), NULL},
#endif
{ngx_string("auth_gss_map_to_local"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, map_to_local), NULL},
{ngx_string("auth_gss_delegate_credentials"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, delegate_credentials), NULL},
{ngx_string("auth_gss_constrained_delegation"), SPNEGO_NGX_CONF_FLAGS,
ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET,
offsetof(ngx_http_auth_spnego_loc_conf_t, constrained_delegation), NULL},
ngx_null_command};
/* Module Context */
static ngx_http_module_t ngx_http_auth_spnego_module_ctx = {
NULL, /* preconf */
ngx_http_auth_spnego_init, /* postconf */
NULL, /* create main conf (defaults) */
NULL, /* init main conf (what's in nginx.conf) */
NULL, /* create server conf */
NULL, /* merge with main */
ngx_http_auth_spnego_create_loc_conf, /* create location conf */
ngx_http_auth_spnego_merge_loc_conf, /* merge with server */
};
/* Module Definition */
ngx_module_t ngx_http_auth_spnego_module = {
/* ngx_uint_t ctx_index, index, spare{0-3}, version; */
NGX_MODULE_V1, /* 0, 0, 0, 0, 0, 0, 1 */
&ngx_http_auth_spnego_module_ctx, /* void *ctx */
ngx_http_auth_spnego_commands, /* ngx_command_t *commands */
NGX_HTTP_MODULE, /* ngx_uint_t type = 0x50545448 */
NULL, /* ngx_int_t (*init_master)(ngx_log_t *log) */
NULL, /* ngx_int_t (*init_module)(ngx_cycle_t *cycle) */
NULL, /* ngx_int_t (*init_process)(ngx_cycle_t *cycle) */
NULL, /* ngx_int_t (*init_thread)(ngx_cycle_t *cycle) */
NULL, /* void (*exit_thread)(ngx_cycle_t *cycle) */
NULL, /* void (*exit_process)(ngx_cycle_t *cycle) */
NULL, /* void (*exit_master)(ngx_cycle_t *cycle) */
NGX_MODULE_V1_PADDING, /* 0, 0, 0, 0, 0, 0, 0, 0 */
/* uintptr_t spare_hook{0-7}; */
};
#if (NGX_PCRE)
static char *ngx_conf_set_regex_array_slot(ngx_conf_t *cf, ngx_command_t *cmd,
void *conf) {
char *p = conf;
u_char errstr[NGX_MAX_CONF_ERRSTR];
ngx_str_t *value;
ngx_regex_elt_t *re;
ngx_regex_compile_t rc;
ngx_array_t **a;
ngx_conf_post_t *post;
a = (ngx_array_t **)(p + cmd->offset);
if (*a == NGX_CONF_UNSET_PTR) {
*a = ngx_array_create(cf->pool, 4, sizeof(ngx_regex_elt_t));
if (*a == NULL) {
return NGX_CONF_ERROR;
}
}
re = ngx_array_push(*a);
if (re == NULL) {
return NGX_CONF_ERROR;
}
value = cf->args->elts;
ngx_memzero(&rc, sizeof(ngx_regex_compile_t));
rc.pattern = value[1];
rc.pool = cf->pool;
rc.err.len = NGX_MAX_CONF_ERRSTR;
rc.err.data = errstr;
if (ngx_regex_compile(&rc) != NGX_OK) {
return NGX_CONF_ERROR;
}
re->regex = rc.regex;
re->name = value[1].data;
if (cmd->post) {
post = cmd->post;
return post->post_handler(cf, post, re);
}
return NGX_CONF_OK;
}
#endif
static void *ngx_http_auth_spnego_create_loc_conf(ngx_conf_t *cf) {
ngx_http_auth_spnego_loc_conf_t *conf;
conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_auth_spnego_loc_conf_t));
if (NULL == conf) {
return NGX_CONF_ERROR;
}
conf->protect = NGX_CONF_UNSET;
conf->fqun = NGX_CONF_UNSET;
conf->force_realm = NGX_CONF_UNSET;
conf->allow_basic = NGX_CONF_UNSET;
conf->auth_princs = NGX_CONF_UNSET_PTR;
#if (NGX_PCRE)
conf->auth_princs_regex = NGX_CONF_UNSET_PTR;
#endif
conf->map_to_local = NGX_CONF_UNSET;
conf->delegate_credentials = NGX_CONF_UNSET;
conf->constrained_delegation = NGX_CONF_UNSET;
return conf;
}
static char *ngx_http_auth_spnego_merge_loc_conf(ngx_conf_t *cf, void *parent,
void *child) {
ngx_http_auth_spnego_loc_conf_t *prev = parent;
ngx_http_auth_spnego_loc_conf_t *conf = child;
/* "off" by default */
ngx_conf_merge_off_value(conf->protect, prev->protect, 0);
ngx_conf_merge_str_value(conf->realm, prev->realm, "");
ngx_conf_merge_str_value(conf->keytab, prev->keytab, "/etc/krb5.keytab");
ngx_conf_merge_str_value(conf->service_ccache, prev->service_ccache, "");
ngx_conf_merge_str_value(conf->srvcname, prev->srvcname, "");
ngx_conf_merge_off_value(conf->fqun, prev->fqun, 0);
ngx_conf_merge_off_value(conf->force_realm, prev->force_realm, 0);
ngx_conf_merge_off_value(conf->allow_basic, prev->allow_basic, 1);
ngx_conf_merge_ptr_value(conf->auth_princs, prev->auth_princs,
NGX_CONF_UNSET_PTR);
#if (NGX_PCRE)
ngx_conf_merge_ptr_value(conf->auth_princs_regex, prev->auth_princs_regex,
NGX_CONF_UNSET_PTR);
#endif
ngx_conf_merge_off_value(conf->map_to_local, prev->map_to_local, 0);
ngx_conf_merge_off_value(conf->delegate_credentials,
prev->delegate_credentials, 0);
ngx_conf_merge_off_value(conf->constrained_delegation,
prev->constrained_delegation, 0);
#if (NGX_DEBUG)
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: protect = %i",
conf->protect);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: realm@0x%p = %s",
conf->realm.data, conf->realm.data);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: keytab@0x%p = %s",
conf->keytab.data, conf->keytab.data);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0,
"auth_spnego: service_ccache@0x%p = %s",
conf->service_ccache.data, conf->service_ccache.data);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: srvcname@0x%p = %s",
conf->srvcname.data, conf->srvcname.data);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: fqun = %i",
conf->fqun);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: allow_basic = %i",
conf->allow_basic);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: force_realm = %i",
conf->force_realm);
if (NGX_CONF_UNSET_PTR != conf->auth_princs) {
size_t ii = 0;
ngx_str_t *auth_princs = conf->auth_princs->elts;
for (; ii < conf->auth_princs->nelts; ++ii) {
ngx_conf_log_error(NGX_LOG_DEBUG, cf, 0,
"auth_spnego: auth_princs = %.*s",
auth_princs[ii].len, auth_princs[ii].data);
}
}
#if (NGX_PCRE)
if (NGX_CONF_UNSET_PTR != conf->auth_princs_regex) {
size_t ii = 0;
ngx_regex_elt_t *auth_princs_regex = conf->auth_princs_regex->elts;
for (; ii < conf->auth_princs_regex->nelts; ++ii) {
ngx_conf_log_error(NGX_LOG_DEBUG, cf, 0,
"auth_spnego: auth_princs_regex = %.*s",
ngx_strlen(auth_princs_regex[ii].name),
auth_princs_regex[ii].name);
}
}
#endif
ngx_conf_log_error(NGX_LOG_INFO, cf, 0, "auth_spnego: map_to_local = %i",
conf->map_to_local);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0,
"auth_spnego: delegate_credentials = %i",
conf->delegate_credentials);
ngx_conf_log_error(NGX_LOG_INFO, cf, 0,
"auth_spnego: constrained_delegation = %i",
conf->constrained_delegation);
#endif
return NGX_CONF_OK;
}
static ngx_int_t ngx_http_auth_spnego_get_handler(ngx_http_request_t *r,
ngx_http_variable_value_t *v,
uintptr_t data) {
return NGX_OK;
}
static ngx_int_t ngx_http_auth_spnego_set_variable(ngx_http_request_t *r,
ngx_str_t *name,
ngx_str_t *value) {
u_char *lowercase = ngx_palloc(r->pool, name->len);
ngx_uint_t key = ngx_hash_strlow(lowercase, name->data, name->len);
ngx_pfree(r->pool, lowercase);
ngx_http_variable_value_t *v = ngx_http_get_variable(r, name, key);
if (v == NULL) {
return NGX_ERROR;
}
v->len = value->len;
v->data = value->data;
return NGX_OK;
}
static ngx_int_t ngx_http_auth_spnego_add_variable(ngx_conf_t *cf,
ngx_str_t *name) {
ngx_http_variable_t *var =
ngx_http_add_variable(cf, name, NGX_HTTP_VAR_NOCACHEABLE);
if (var == NULL) {
return NGX_ERROR;
}
var->get_handler = ngx_http_auth_spnego_get_handler;
var->data = 0;
return NGX_OK;
}
static ngx_int_t ngx_http_auth_spnego_init_shm_zone(ngx_shm_zone_t *shm_zone,
void *data) {
if (data) {
shm_zone->data = data;
return NGX_OK;
}
shm_zone->data = shm_zone->shm.addr;
return NGX_OK;
}
static ngx_int_t ngx_http_auth_spnego_create_shm_zone(ngx_conf_t *cf) {
ngx_str_t name = ngx_string(SHM_ZONE_NAME);
shm_zone =
ngx_shared_memory_add(cf, &name, 65536, &ngx_http_auth_spnego_module);
if (shm_zone == NULL) {
return NGX_ERROR;
}
shm_zone->init = ngx_http_auth_spnego_init_shm_zone;
return NGX_OK;
}
static ngx_int_t ngx_http_auth_spnego_init(ngx_conf_t *cf) {
ngx_http_handler_pt *h;
ngx_http_core_main_conf_t *cmcf;
cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
h = ngx_array_push(&cmcf->phases[NGX_HTTP_ACCESS_PHASE].handlers);
if (NULL == h) {
return NGX_ERROR;
}
*h = ngx_http_auth_spnego_handler;
if (ngx_http_auth_spnego_create_shm_zone(cf) != NGX_OK) {
return NGX_ERROR;
}
ngx_str_t var_name = ngx_string(CCACHE_VARIABLE_NAME);
if (ngx_http_auth_spnego_add_variable(cf, &var_name) != NGX_OK) {
return NGX_ERROR;
}
return NGX_OK;
}
static ngx_int_t
ngx_http_auth_spnego_headers_basic_only(ngx_http_request_t *r,
ngx_http_auth_spnego_ctx_t *ctx,
ngx_http_auth_spnego_loc_conf_t *alcf) {
ngx_str_t value = ngx_null_string;
value.len = sizeof("Basic realm=\"\"") - 1 + alcf->realm.len;
value.data = ngx_pcalloc(r->pool, value.len);
if (NULL == value.data) {
return NGX_ERROR;
}
ngx_snprintf(value.data, value.len, "Basic realm=\"%V\"", &alcf->realm);
r->headers_out.www_authenticate = ngx_list_push(&r->headers_out.headers);
if (NULL == r->headers_out.www_authenticate) {
return NGX_ERROR;
}
r->headers_out.www_authenticate->hash = 1;
r->headers_out.www_authenticate->key.len = sizeof("WWW-Authenticate") - 1;
r->headers_out.www_authenticate->key.data = (u_char *)"WWW-Authenticate";
r->headers_out.www_authenticate->value.len = value.len;
r->headers_out.www_authenticate->value.data = value.data;
ctx->head = 1;
return NGX_OK;
}
static ngx_int_t
ngx_http_auth_spnego_headers(ngx_http_request_t *r,
ngx_http_auth_spnego_ctx_t *ctx, ngx_str_t *token,
ngx_http_auth_spnego_loc_conf_t *alcf) {
ngx_str_t value = ngx_null_string;
/* only use token if authorized as there appears to be a bug in
* Google Chrome when parsing a 401 Negotiate with a token */
if (NULL == token || ctx->ret != NGX_OK) {
value.len = sizeof("Negotiate") - 1;
value.data = (u_char *)"Negotiate";
} else {
value.len =
sizeof("Negotiate") + token->len; /* space accounts for \0 */
value.data = ngx_pcalloc(r->pool, value.len);
if (NULL == value.data) {
return NGX_ERROR;
}
ngx_snprintf(value.data, value.len, "Negotiate %V", token);
}
r->headers_out.www_authenticate = ngx_list_push(&r->headers_out.headers);
if (NULL == r->headers_out.www_authenticate) {
return NGX_ERROR;
}
r->headers_out.www_authenticate->hash = 1;
r->headers_out.www_authenticate->key.len = sizeof("WWW-Authenticate") - 1;
r->headers_out.www_authenticate->key.data = (u_char *)"WWW-Authenticate";
r->headers_out.www_authenticate->value.len = value.len;
r->headers_out.www_authenticate->value.data = value.data;
if (alcf->allow_basic) {
ngx_str_t value2 = ngx_null_string;
value2.len = sizeof("Basic realm=\"\"") - 1 + alcf->realm.len;
value2.data = ngx_pcalloc(r->pool, value2.len);
if (NULL == value2.data) {
return NGX_ERROR;
}
ngx_snprintf(value2.data, value2.len, "Basic realm=\"%V\"",
&alcf->realm);
r->headers_out.www_authenticate =
ngx_list_push(&r->headers_out.headers);
if (NULL == r->headers_out.www_authenticate) {
return NGX_ERROR;
}
r->headers_out.www_authenticate->hash = 2;
r->headers_out.www_authenticate->key.len =
sizeof("WWW-Authenticate") - 1;
r->headers_out.www_authenticate->key.data =
(u_char *)"WWW-Authenticate";
r->headers_out.www_authenticate->value.len = value2.len;
r->headers_out.www_authenticate->value.data = value2.data;
}
ctx->head = 1;
return NGX_OK;
}
static bool
ngx_spnego_authorized_principal(ngx_http_request_t *r, ngx_str_t *princ,
ngx_http_auth_spnego_loc_conf_t *alcf) {
if (NGX_CONF_UNSET_PTR == alcf->auth_princs
#if (NGX_PCRE)
&& NGX_CONF_UNSET_PTR == alcf->auth_princs_regex
#endif
) {
return true;
}
if (NGX_CONF_UNSET_PTR != alcf->auth_princs) {
spnego_debug1("Testing against %d auth princs",
alcf->auth_princs->nelts);
ngx_str_t *auth_princs = alcf->auth_princs->elts;
size_t i = 0;
for (; i < alcf->auth_princs->nelts; ++i) {
if (auth_princs[i].len != princ->len) {
continue;
}
if (ngx_strncmp(auth_princs[i].data, princ->data, princ->len) ==
0) {
spnego_debug2("Authorized user %.*s", princ->len, princ->data);
return true;
}
}
}
#if (NGX_PCRE)
if (NGX_CONF_UNSET_PTR != alcf->auth_princs_regex) {
spnego_debug1("Testing against %d auth princs regex",
alcf->auth_princs_regex->nelts);
if (ngx_regex_exec_array(alcf->auth_princs_regex, princ,
r->connection->log) == NGX_OK) {
return true;
}
}
#endif
return false;
}
ngx_int_t ngx_http_auth_spnego_token(ngx_http_request_t *r,
ngx_http_auth_spnego_ctx_t *ctx) {
ngx_str_t token;
ngx_str_t decoded;
size_t nego_sz = sizeof("Negotiate");
if (NULL == r->headers_in.authorization) {
return NGX_DECLINED;
}
/* but don't decode second time? */
if (ctx->token.len)
return NGX_OK;
token = r->headers_in.authorization->value;
if (token.len < nego_sz ||
ngx_strncasecmp(token.data, (u_char *)"Negotiate ", nego_sz) != 0) {
if (ngx_strncasecmp(token.data, (u_char *)"NTLM", sizeof("NTLM")) ==
0) {
spnego_log_error("Detected unsupported mechanism: NTLM");
}
return NGX_DECLINED;
}
token.len -= nego_sz;
token.data += nego_sz;
while (token.len && token.data[0] == ' ') {
token.len--;
token.data++;
}
if (token.len == 0) {
return NGX_DECLINED;
}
decoded.len = ngx_base64_decoded_length(token.len);
decoded.data = ngx_pnalloc(r->pool, decoded.len);
if (NULL == decoded.data) {
return NGX_ERROR;
}
if (ngx_decode_base64(&decoded, &token) != NGX_OK) {
return NGX_DECLINED;
}
ctx->token.len = decoded.len;
ctx->token.data = decoded.data;
spnego_debug2("Token decoded: %*s", token.len, token.data);
return NGX_OK;
}
static krb5_error_code ngx_http_auth_spnego_store_krb5_creds(
ngx_http_request_t *r, krb5_context kcontext, krb5_principal principal,
krb5_ccache ccache, krb5_creds creds) {
krb5_error_code kerr = 0;
if ((kerr = krb5_cc_initialize(kcontext, ccache, principal))) {
spnego_log_error("Kerberos error: Cannot initialize ccache");
spnego_log_krb5_error(kcontext, kerr);
return kerr;
}
if ((kerr = krb5_cc_store_cred(kcontext, ccache, &creds))) {
spnego_log_error("Kerberos error: Cannot store credentials");
spnego_log_krb5_error(kcontext, kerr);
return kerr;
}
return kerr;
}
static krb5_error_code ngx_http_auth_spnego_store_gss_creds(
ngx_http_request_t *r, krb5_context kcontext, krb5_principal principal,
krb5_ccache ccache, gss_cred_id_t creds) {
OM_uint32 major_status, minor_status;
krb5_error_code kerr = 0;
if ((kerr = krb5_cc_initialize(kcontext, ccache, principal))) {
spnego_log_error("Kerberos error: Cannot initialize ccache");
spnego_log_krb5_error(kcontext, kerr);
return kerr;
}
major_status = gss_krb5_copy_ccache(&minor_status, creds, ccache);
if (GSS_ERROR(major_status)) {
const char *gss_error =
get_gss_error(r->pool, minor_status,
"ngx_http_auth_spnego_store_gss_creds() failed");
spnego_log_error("%s", gss_error);
spnego_debug1("%s", gss_error);
return KRB5_CC_WRITE;
}
return kerr;
}
static void ngx_http_auth_spnego_krb5_destroy_ccache(void *data) {
krb5_context kcontext;
krb5_ccache ccache;
krb5_error_code kerr = 0;
char *ccname = (char *)data;
if ((kerr = krb5_init_context(&kcontext))) {
goto done;
}
if ((kerr = krb5_cc_resolve(kcontext, ccname, &ccache))) {
goto done;
}
krb5_cc_destroy(kcontext, ccache);
done:
if (kcontext)
krb5_free_context(kcontext);
}
static char *ngx_http_auth_spnego_replace(ngx_http_request_t *r, char *str,
char find, char replace) {
char *result = (char *)ngx_palloc(r->pool, ngx_strlen(str) + 1);
ngx_memcpy(result, str, ngx_strlen(str) + 1);
char *index = NULL;
while ((index = ngx_strchr(result, find)) != NULL) {
*index = replace;
}
return result;
}
static ngx_int_t
ngx_http_auth_spnego_store_delegated_creds(ngx_http_request_t *r,
ngx_str_t *principal_name,
creds_info delegated_creds) {
krb5_context kcontext = NULL;
krb5_principal principal = NULL;
krb5_ccache ccache = NULL;
krb5_error_code kerr = 0;
char *ccname = NULL;
char *escaped = NULL;
if (!delegated_creds.data) {
spnego_log_error(
"ngx_http_auth_spnego_store_delegated_creds() NULL credentials");
spnego_debug0(
"ngx_http_auth_spnego_store_delegated_creds() NULL credentials");
goto done;
}
if ((kerr = krb5_init_context(&kcontext))) {
spnego_log_error("Kerberos error: Cannot initialize kerberos context");
spnego_log_krb5_error(kcontext, kerr);
goto done;
}
if ((kerr = krb5_parse_name(kcontext, (char *)principal_name->data,
&principal))) {
spnego_log_error("Kerberos error: Cannot parse principal %s",
principal_name);
spnego_log_krb5_error(kcontext, kerr);
goto done;
}
escaped =
ngx_http_auth_spnego_replace(r, (char *)principal_name->data, '/', '_');
size_t ccname_size = (ngx_strlen("FILE:") + ngx_strlen(P_tmpdir) +
ngx_strlen("/") + ngx_strlen(escaped)) +
1;
ccname = (char *)ngx_pcalloc(r->pool, ccname_size);
ngx_snprintf((u_char *)ccname, ccname_size, "FILE:%s/%*s", P_tmpdir,
ngx_strlen(escaped), escaped);
if ((kerr = krb5_cc_resolve(kcontext, ccname, &ccache))) {
spnego_log_error("Kerberos error: Cannot resolve ccache %s", ccname);
spnego_log_krb5_error(kcontext, kerr);
goto done;
}
switch (delegated_creds.type) {
case TYPE_GSS_CRED_ID_T:
kerr = ngx_http_auth_spnego_store_gss_creds(
r, kcontext, principal, ccache,
(gss_cred_id_t)delegated_creds.data);
break;
case TYPE_KRB5_CREDS:
kerr = ngx_http_auth_spnego_store_krb5_creds(
r, kcontext, principal, ccache,
(*(krb5_creds *)delegated_creds.data));
break;
default:
kerr = KRB5KRB_ERR_GENERIC;
}
if (kerr)
goto done;
ngx_str_t var_name = ngx_string(CCACHE_VARIABLE_NAME);
ngx_str_t var_value = ngx_null_string;
var_value.data = (u_char *)ccname;
var_value.len = ngx_strlen(ccname);
ngx_http_auth_spnego_set_variable(r, &var_name, &var_value);
ngx_pool_cleanup_t *cln = ngx_pool_cleanup_add(r->pool, 0);
cln->handler = ngx_http_auth_spnego_krb5_destroy_ccache;
cln->data = ccname;
done:
if (escaped)
ngx_pfree(r->pool, escaped);
if (ccname)
ngx_pfree(r->pool, ccname);
if (principal)
krb5_free_principal(kcontext, principal);
if (ccache)
krb5_cc_close(kcontext, ccache);
if (kcontext)
krb5_free_context(kcontext);
return kerr ? NGX_ERROR : NGX_OK;
}
ngx_int_t ngx_http_auth_spnego_basic(ngx_http_request_t *r,
ngx_http_auth_spnego_ctx_t *ctx,
ngx_http_auth_spnego_loc_conf_t *alcf) {
ngx_str_t host_name;
ngx_str_t service;
ngx_str_t user;
user.data = NULL;
ngx_str_t new_user;
ngx_int_t ret = NGX_DECLINED;
krb5_context kcontext = NULL;
krb5_error_code code;
krb5_principal client = NULL;
krb5_principal server = NULL;
krb5_creds creds;
krb5_get_init_creds_opt *gic_options = NULL;
int kret = 0;
char *name = NULL;
char *p = NULL;
code = krb5_init_context(&kcontext);
if (code) {
spnego_debug0("Kerberos error: Cannot initialize kerberos context");
return NGX_ERROR;
}
host_name = r->headers_in.host->value;
service.len = alcf->srvcname.len + alcf->realm.len + 3;
if (ngx_strchr(alcf->srvcname.data, '/')) {
service.data = ngx_palloc(r->pool, service.len);
if (NULL == service.data) {
spnego_error(NGX_ERROR);
}
ngx_snprintf(service.data, service.len, "%V@%V%Z", &alcf->srvcname,
&alcf->realm);
} else {
service.len += host_name.len;
service.data = ngx_palloc(r->pool, service.len);
if (NULL == service.data) {
spnego_error(NGX_ERROR);
}
ngx_snprintf(service.data, service.len, "%V/%V@%V%Z", &alcf->srvcname,
&host_name, &alcf->realm);
}
kret = krb5_parse_name(kcontext, (const char *)service.data, &server);
if (kret) {
spnego_log_error("Kerberos error: Unable to parse service name");
spnego_log_krb5_error(kcontext, code);
spnego_error(NGX_ERROR);
}
code = krb5_unparse_name(kcontext, server, &name);
if (code) {
spnego_log_error("Kerberos error: Cannot unparse servicename");
spnego_log_krb5_error(kcontext, code);
spnego_error(NGX_ERROR);
}
free(name);
name = NULL;
p = ngx_strchr(r->headers_in.user.data, '@');
user.len = r->headers_in.user.len + 1;
if (NULL == p) {
if (alcf->force_realm && alcf->realm.len && alcf->realm.data) {
user.len += alcf->realm.len + 1; /* +1 for @ */
user.data = ngx_palloc(r->pool, user.len);
if (NULL == user.data) {
spnego_log_error("Not enough memory");
spnego_error(NGX_ERROR);
}
ngx_snprintf(user.data, user.len, "%V@%V%Z", &r->headers_in.user,
&alcf->realm);
} else {
user.data = ngx_palloc(r->pool, user.len);
if (NULL == user.data) {
spnego_log_error("Not enough memory");
spnego_error(NGX_ERROR);
}
ngx_snprintf(user.data, user.len, "%V%Z", &r->headers_in.user);
}
} else {
if (alcf->realm.len && alcf->realm.data &&
ngx_strncmp(p + 1, alcf->realm.data, alcf->realm.len) == 0) {
user.data = ngx_palloc(r->pool, user.len);
if (NULL == user.data) {
spnego_log_error("Not enough memory");
spnego_error(NGX_ERROR);
}
ngx_snprintf(user.data, user.len, "%V%Z", &r->headers_in.user);
if (alcf->fqun == 0) {
/*
* Specified realm is identical to configured realm.
* Truncate $remote_user to strip @REALM.
*/
r->headers_in.user.len -= alcf->realm.len + 1;
}
} else if (alcf->force_realm) {
*p = '\0';
user.len = ngx_strlen(r->headers_in.user.data) + 1;
if (alcf->realm.len && alcf->realm.data)
user.len += alcf->realm.len + 1;
user.data = ngx_pcalloc(r->pool, user.len);
if (NULL == user.data) {
spnego_log_error("Not enough memory");
spnego_error(NGX_ERROR);
}
if (alcf->realm.len && alcf->realm.data)
ngx_snprintf(user.data, user.len, "%s@%V%Z",
r->headers_in.user.data, &alcf->realm);
else
ngx_snprintf(user.data, user.len, "%s%Z",
r->headers_in.user.data);
/*
* Rewrite $remote_user with the forced realm.
* If the forced realm is shorter than the
* specified realm, we can reuse the original
* buffer.
*/
if (r->headers_in.user.len >= user.len - 1)
r->headers_in.user.len = user.len - 1;
else {
new_user.len = user.len - 1;
new_user.data = ngx_palloc(r->pool, new_user.len);
if (NULL == new_user.data) {
spnego_log_error("Not enough memory");
spnego_error(NGX_ERROR);
}
ngx_pfree(r->pool, r->headers_in.user.data);
r->headers_in.user.data = new_user.data;
r->headers_in.user.len = new_user.len;
}
ngx_memcpy(r->headers_in.user.data, user.data,
r->headers_in.user.len);
} else {
user.data = ngx_palloc(r->pool, user.len);
if (NULL == user.data) {
spnego_log_error("Not enough memory");
spnego_error(NGX_ERROR);
}
ngx_snprintf(user.data, user.len, "%V%Z", &r->headers_in.user);
}
}
spnego_debug1("Attempting authentication with principal %s",
(const char *)user.data);