Mercurial > hg > nginx
view src/http/modules/ngx_http_auth_basic_module.c @ 7629:f47f7d3d1bfa
Mp4: fixed possible chunk offset overflow.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 26 Feb 2020 15:10:46 +0300 |
parents | e48ac0136ee3 |
children | 0cb942c1c1aa |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #include <ngx_crypt.h> #define NGX_HTTP_AUTH_BUF_SIZE 2048 typedef struct { ngx_http_complex_value_t *realm; ngx_http_complex_value_t user_file; } ngx_http_auth_basic_loc_conf_t; static ngx_int_t ngx_http_auth_basic_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_auth_basic_crypt_handler(ngx_http_request_t *r, ngx_str_t *passwd, ngx_str_t *realm); static ngx_int_t ngx_http_auth_basic_set_realm(ngx_http_request_t *r, ngx_str_t *realm); static void ngx_http_auth_basic_close(ngx_file_t *file); static void *ngx_http_auth_basic_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_auth_basic_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_auth_basic_init(ngx_conf_t *cf); static char *ngx_http_auth_basic_user_file(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_auth_basic_commands[] = { { ngx_string("auth_basic"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LMT_CONF |NGX_CONF_TAKE1, ngx_http_set_complex_value_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_auth_basic_loc_conf_t, realm), NULL }, { ngx_string("auth_basic_user_file"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LMT_CONF |NGX_CONF_TAKE1, ngx_http_auth_basic_user_file, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_auth_basic_loc_conf_t, user_file), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_auth_basic_module_ctx = { NULL, /* preconfiguration */ ngx_http_auth_basic_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_auth_basic_create_loc_conf, /* create location configuration */ ngx_http_auth_basic_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_auth_basic_module = { NGX_MODULE_V1, &ngx_http_auth_basic_module_ctx, /* module context */ ngx_http_auth_basic_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_http_auth_basic_handler(ngx_http_request_t *r) { off_t offset; ssize_t n; ngx_fd_t fd; ngx_int_t rc; ngx_err_t err; ngx_str_t pwd, realm, user_file; ngx_uint_t i, level, login, left, passwd; ngx_file_t file; ngx_http_auth_basic_loc_conf_t *alcf; u_char buf[NGX_HTTP_AUTH_BUF_SIZE]; enum { sw_login, sw_passwd, sw_skip } state; alcf = ngx_http_get_module_loc_conf(r, ngx_http_auth_basic_module); if (alcf->realm == NULL || alcf->user_file.value.data == NULL) { return NGX_DECLINED; } if (ngx_http_complex_value(r, alcf->realm, &realm) != NGX_OK) { return NGX_ERROR; } if (realm.len == 3 && ngx_strncmp(realm.data, "off", 3) == 0) { return NGX_DECLINED; } rc = ngx_http_auth_basic_user(r); if (rc == NGX_DECLINED) { ngx_log_error(NGX_LOG_INFO, r->connection->log, 0, "no user/password was provided for basic authentication"); return ngx_http_auth_basic_set_realm(r, &realm); } if (rc == NGX_ERROR) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (ngx_http_complex_value(r, &alcf->user_file, &user_file) != NGX_OK) { return NGX_ERROR; } fd = ngx_open_file(user_file.data, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0); if (fd == NGX_INVALID_FILE) { err = ngx_errno; if (err == NGX_ENOENT) { level = NGX_LOG_ERR; rc = NGX_HTTP_FORBIDDEN; } else { level = NGX_LOG_CRIT; rc = NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_log_error(level, r->connection->log, err, ngx_open_file_n " \"%s\" failed", user_file.data); return rc; } ngx_memzero(&file, sizeof(ngx_file_t)); file.fd = fd; file.name = user_file; file.log = r->connection->log; state = sw_login; passwd = 0; login = 0; left = 0; offset = 0; for ( ;; ) { i = left; n = ngx_read_file(&file, buf + left, NGX_HTTP_AUTH_BUF_SIZE - left, offset); if (n == NGX_ERROR) { ngx_http_auth_basic_close(&file); return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (n == 0) { break; } for (i = left; i < left + n; i++) { switch (state) { case sw_login: if (login == 0) { if (buf[i] == '#' || buf[i] == CR) { state = sw_skip; break; } if (buf[i] == LF) { break; } } if (buf[i] != r->headers_in.user.data[login]) { state = sw_skip; break; } if (login == r->headers_in.user.len) { state = sw_passwd; passwd = i + 1; } login++; break; case sw_passwd: if (buf[i] == LF || buf[i] == CR || buf[i] == ':') { buf[i] = '\0'; ngx_http_auth_basic_close(&file); pwd.len = i - passwd; pwd.data = &buf[passwd]; return ngx_http_auth_basic_crypt_handler(r, &pwd, &realm); } break; case sw_skip: if (buf[i] == LF) { state = sw_login; login = 0; } break; } } if (state == sw_passwd) { left = left + n - passwd; ngx_memmove(buf, &buf[passwd], left); passwd = 0; } else { left = 0; } offset += n; } ngx_http_auth_basic_close(&file); if (state == sw_passwd) { pwd.len = i - passwd; pwd.data = ngx_pnalloc(r->pool, pwd.len + 1); if (pwd.data == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_cpystrn(pwd.data, &buf[passwd], pwd.len + 1); return ngx_http_auth_basic_crypt_handler(r, &pwd, &realm); } ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "user \"%V\" was not found in \"%s\"", &r->headers_in.user, user_file.data); return ngx_http_auth_basic_set_realm(r, &realm); } static ngx_int_t ngx_http_auth_basic_crypt_handler(ngx_http_request_t *r, ngx_str_t *passwd, ngx_str_t *realm) { ngx_int_t rc; u_char *encrypted; rc = ngx_crypt(r->pool, r->headers_in.passwd.data, passwd->data, &encrypted); ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "rc: %i user: \"%V\" salt: \"%s\"", rc, &r->headers_in.user, passwd->data); if (rc != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } if (ngx_strcmp(encrypted, passwd->data) == 0) { return NGX_OK; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "encrypted: \"%s\"", encrypted); ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "user \"%V\": password mismatch", &r->headers_in.user); return ngx_http_auth_basic_set_realm(r, realm); } static ngx_int_t ngx_http_auth_basic_set_realm(ngx_http_request_t *r, ngx_str_t *realm) { size_t len; u_char *basic, *p; r->headers_out.www_authenticate = ngx_list_push(&r->headers_out.headers); if (r->headers_out.www_authenticate == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } len = sizeof("Basic realm=\"\"") - 1 + realm->len; basic = ngx_pnalloc(r->pool, len); if (basic == NULL) { r->headers_out.www_authenticate->hash = 0; r->headers_out.www_authenticate = NULL; return NGX_HTTP_INTERNAL_SERVER_ERROR; } p = ngx_cpymem(basic, "Basic realm=\"", sizeof("Basic realm=\"") - 1); p = ngx_cpymem(p, realm->data, realm->len); *p = '"'; r->headers_out.www_authenticate->hash = 1; ngx_str_set(&r->headers_out.www_authenticate->key, "WWW-Authenticate"); r->headers_out.www_authenticate->value.data = basic; r->headers_out.www_authenticate->value.len = len; return NGX_HTTP_UNAUTHORIZED; } static void ngx_http_auth_basic_close(ngx_file_t *file) { if (ngx_close_file(file->fd) == NGX_FILE_ERROR) { ngx_log_error(NGX_LOG_ALERT, file->log, ngx_errno, ngx_close_file_n " \"%s\" failed", file->name.data); } } static void * ngx_http_auth_basic_create_loc_conf(ngx_conf_t *cf) { ngx_http_auth_basic_loc_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_auth_basic_loc_conf_t)); if (conf == NULL) { return NULL; } return conf; } static char * ngx_http_auth_basic_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_auth_basic_loc_conf_t *prev = parent; ngx_http_auth_basic_loc_conf_t *conf = child; if (conf->realm == NULL) { conf->realm = prev->realm; } if (conf->user_file.value.data == NULL) { conf->user_file = prev->user_file; } return NGX_CONF_OK; } static ngx_int_t ngx_http_auth_basic_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 (h == NULL) { return NGX_ERROR; } *h = ngx_http_auth_basic_handler; return NGX_OK; } static char * ngx_http_auth_basic_user_file(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_auth_basic_loc_conf_t *alcf = conf; ngx_str_t *value; ngx_http_compile_complex_value_t ccv; if (alcf->user_file.value.data) { return "is duplicate"; } value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &alcf->user_file; ccv.zero = 1; ccv.conf_prefix = 1; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } return NGX_CONF_OK; }