Mercurial > hg > nginx
view src/mail/ngx_mail_ssl_module.c @ 7094:c7d4017c8876
Secure link: fixed stack buffer overflow.
When secure link checksum has length of 23 or 24 bytes, decoded base64 value
could occupy 17 or 18 bytes which is more than 16 bytes previously allocated
for it on stack. The buffer overflow does not have any security implications
since only one local variable was corrupted and this variable was not used in
this case.
The fix is to increase buffer size up to 18 bytes. Useless buffer size
initialization is removed as well.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 22 Aug 2017 21:22:59 +0300 |
parents | 08dc60979133 |
children | 0d8c72ff62dd |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_mail.h> #define NGX_DEFAULT_CIPHERS "HIGH:!aNULL:!MD5" #define NGX_DEFAULT_ECDH_CURVE "auto" static void *ngx_mail_ssl_create_conf(ngx_conf_t *cf); static char *ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child); static char *ngx_mail_ssl_enable(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_mail_ssl_starttls(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_mail_ssl_password_file(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_mail_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_conf_enum_t ngx_mail_starttls_state[] = { { ngx_string("off"), NGX_MAIL_STARTTLS_OFF }, { ngx_string("on"), NGX_MAIL_STARTTLS_ON }, { ngx_string("only"), NGX_MAIL_STARTTLS_ONLY }, { ngx_null_string, 0 } }; static ngx_conf_bitmask_t ngx_mail_ssl_protocols[] = { { ngx_string("SSLv2"), NGX_SSL_SSLv2 }, { ngx_string("SSLv3"), NGX_SSL_SSLv3 }, { ngx_string("TLSv1"), NGX_SSL_TLSv1 }, { ngx_string("TLSv1.1"), NGX_SSL_TLSv1_1 }, { ngx_string("TLSv1.2"), NGX_SSL_TLSv1_2 }, { ngx_string("TLSv1.3"), NGX_SSL_TLSv1_3 }, { ngx_null_string, 0 } }; static ngx_conf_enum_t ngx_mail_ssl_verify[] = { { ngx_string("off"), 0 }, { ngx_string("on"), 1 }, { ngx_string("optional"), 2 }, { ngx_string("optional_no_ca"), 3 }, { ngx_null_string, 0 } }; static ngx_command_t ngx_mail_ssl_commands[] = { { ngx_string("ssl"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_mail_ssl_enable, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, enable), NULL }, { ngx_string("starttls"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_mail_ssl_starttls, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, starttls), ngx_mail_starttls_state }, { ngx_string("ssl_certificate"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_array_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, certificates), NULL }, { ngx_string("ssl_certificate_key"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_array_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, certificate_keys), NULL }, { ngx_string("ssl_password_file"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_mail_ssl_password_file, NGX_MAIL_SRV_CONF_OFFSET, 0, NULL }, { ngx_string("ssl_dhparam"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, dhparam), NULL }, { ngx_string("ssl_ecdh_curve"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, ecdh_curve), NULL }, { ngx_string("ssl_protocols"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_conf_set_bitmask_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, protocols), &ngx_mail_ssl_protocols }, { ngx_string("ssl_ciphers"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, ciphers), NULL }, { ngx_string("ssl_prefer_server_ciphers"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, prefer_server_ciphers), NULL }, { ngx_string("ssl_session_cache"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE12, ngx_mail_ssl_session_cache, NGX_MAIL_SRV_CONF_OFFSET, 0, NULL }, { ngx_string("ssl_session_tickets"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, session_tickets), NULL }, { ngx_string("ssl_session_ticket_key"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_array_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, session_ticket_keys), NULL }, { ngx_string("ssl_session_timeout"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_sec_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, session_timeout), NULL }, { ngx_string("ssl_verify_client"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_enum_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, verify), &ngx_mail_ssl_verify }, { ngx_string("ssl_verify_depth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_num_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, verify_depth), NULL }, { ngx_string("ssl_client_certificate"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, client_certificate), NULL }, { ngx_string("ssl_trusted_certificate"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, trusted_certificate), NULL }, { ngx_string("ssl_crl"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, crl), NULL }, ngx_null_command }; static ngx_mail_module_t ngx_mail_ssl_module_ctx = { NULL, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_ssl_create_conf, /* create server configuration */ ngx_mail_ssl_merge_conf /* merge server configuration */ }; ngx_module_t ngx_mail_ssl_module = { NGX_MODULE_V1, &ngx_mail_ssl_module_ctx, /* module context */ ngx_mail_ssl_commands, /* module directives */ NGX_MAIL_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_str_t ngx_mail_ssl_sess_id_ctx = ngx_string("MAIL"); static void * ngx_mail_ssl_create_conf(ngx_conf_t *cf) { ngx_mail_ssl_conf_t *scf; scf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_ssl_conf_t)); if (scf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * scf->protocols = 0; * scf->dhparam = { 0, NULL }; * scf->ecdh_curve = { 0, NULL }; * scf->client_certificate = { 0, NULL }; * scf->trusted_certificate = { 0, NULL }; * scf->crl = { 0, NULL }; * scf->ciphers = { 0, NULL }; * scf->shm_zone = NULL; */ scf->enable = NGX_CONF_UNSET; scf->starttls = NGX_CONF_UNSET_UINT; scf->certificates = NGX_CONF_UNSET_PTR; scf->certificate_keys = NGX_CONF_UNSET_PTR; scf->passwords = NGX_CONF_UNSET_PTR; scf->prefer_server_ciphers = NGX_CONF_UNSET; scf->verify = NGX_CONF_UNSET_UINT; scf->verify_depth = NGX_CONF_UNSET_UINT; scf->builtin_session_cache = NGX_CONF_UNSET; scf->session_timeout = NGX_CONF_UNSET; scf->session_tickets = NGX_CONF_UNSET; scf->session_ticket_keys = NGX_CONF_UNSET_PTR; return scf; } static char * ngx_mail_ssl_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_ssl_conf_t *prev = parent; ngx_mail_ssl_conf_t *conf = child; char *mode; ngx_pool_cleanup_t *cln; ngx_conf_merge_value(conf->enable, prev->enable, 0); ngx_conf_merge_uint_value(conf->starttls, prev->starttls, NGX_MAIL_STARTTLS_OFF); ngx_conf_merge_value(conf->session_timeout, prev->session_timeout, 300); ngx_conf_merge_value(conf->prefer_server_ciphers, prev->prefer_server_ciphers, 0); ngx_conf_merge_bitmask_value(conf->protocols, prev->protocols, (NGX_CONF_BITMASK_SET|NGX_SSL_TLSv1 |NGX_SSL_TLSv1_1|NGX_SSL_TLSv1_2)); ngx_conf_merge_uint_value(conf->verify, prev->verify, 0); ngx_conf_merge_uint_value(conf->verify_depth, prev->verify_depth, 1); ngx_conf_merge_ptr_value(conf->certificates, prev->certificates, NULL); ngx_conf_merge_ptr_value(conf->certificate_keys, prev->certificate_keys, NULL); ngx_conf_merge_ptr_value(conf->passwords, prev->passwords, NULL); ngx_conf_merge_str_value(conf->dhparam, prev->dhparam, ""); ngx_conf_merge_str_value(conf->ecdh_curve, prev->ecdh_curve, NGX_DEFAULT_ECDH_CURVE); ngx_conf_merge_str_value(conf->client_certificate, prev->client_certificate, ""); ngx_conf_merge_str_value(conf->trusted_certificate, prev->trusted_certificate, ""); ngx_conf_merge_str_value(conf->crl, prev->crl, ""); ngx_conf_merge_str_value(conf->ciphers, prev->ciphers, NGX_DEFAULT_CIPHERS); conf->ssl.log = cf->log; if (conf->enable) { mode = "ssl"; } else if (conf->starttls != NGX_MAIL_STARTTLS_OFF) { mode = "starttls"; } else { mode = ""; } if (conf->file == NULL) { conf->file = prev->file; conf->line = prev->line; } if (*mode) { if (conf->certificates == NULL) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no \"ssl_certificate\" is defined for " "the \"%s\" directive in %s:%ui", mode, conf->file, conf->line); return NGX_CONF_ERROR; } if (conf->certificate_keys == NULL) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no \"ssl_certificate_key\" is defined for " "the \"%s\" directive in %s:%ui", mode, conf->file, conf->line); return NGX_CONF_ERROR; } if (conf->certificate_keys->nelts < conf->certificates->nelts) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no \"ssl_certificate_key\" is defined " "for certificate \"%V\" and " "the \"ssl\" directive in %s:%ui", ((ngx_str_t *) conf->certificates->elts) + conf->certificates->nelts - 1, conf->file, conf->line); return NGX_CONF_ERROR; } } else { if (conf->certificates == NULL) { return NGX_CONF_OK; } if (conf->certificate_keys == NULL || conf->certificate_keys->nelts < conf->certificates->nelts) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no \"ssl_certificate_key\" is defined " "for certificate \"%V\"", ((ngx_str_t *) conf->certificates->elts) + conf->certificates->nelts - 1); return NGX_CONF_ERROR; } } if (ngx_ssl_create(&conf->ssl, conf->protocols, NULL) != NGX_OK) { return NGX_CONF_ERROR; } cln = ngx_pool_cleanup_add(cf->pool, 0); if (cln == NULL) { return NGX_CONF_ERROR; } cln->handler = ngx_ssl_cleanup_ctx; cln->data = &conf->ssl; if (ngx_ssl_certificates(cf, &conf->ssl, conf->certificates, conf->certificate_keys, conf->passwords) != NGX_OK) { return NGX_CONF_ERROR; } if (conf->verify) { if (conf->client_certificate.len == 0 && conf->verify != 3) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no ssl_client_certificate for ssl_client_verify"); return NGX_CONF_ERROR; } if (ngx_ssl_client_certificate(cf, &conf->ssl, &conf->client_certificate, conf->verify_depth) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_ssl_trusted_certificate(cf, &conf->ssl, &conf->trusted_certificate, conf->verify_depth) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_ssl_crl(cf, &conf->ssl, &conf->crl) != NGX_OK) { return NGX_CONF_ERROR; } } if (ngx_ssl_ciphers(cf, &conf->ssl, &conf->ciphers, conf->prefer_server_ciphers) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_ssl_dhparam(cf, &conf->ssl, &conf->dhparam) != NGX_OK) { return NGX_CONF_ERROR; } if (ngx_ssl_ecdh_curve(cf, &conf->ssl, &conf->ecdh_curve) != NGX_OK) { return NGX_CONF_ERROR; } ngx_conf_merge_value(conf->builtin_session_cache, prev->builtin_session_cache, NGX_SSL_NONE_SCACHE); if (conf->shm_zone == NULL) { conf->shm_zone = prev->shm_zone; } if (ngx_ssl_session_cache(&conf->ssl, &ngx_mail_ssl_sess_id_ctx, conf->builtin_session_cache, conf->shm_zone, conf->session_timeout) != NGX_OK) { return NGX_CONF_ERROR; } ngx_conf_merge_value(conf->session_tickets, prev->session_tickets, 1); #ifdef SSL_OP_NO_TICKET if (!conf->session_tickets) { SSL_CTX_set_options(conf->ssl.ctx, SSL_OP_NO_TICKET); } #endif ngx_conf_merge_ptr_value(conf->session_ticket_keys, prev->session_ticket_keys, NULL); if (ngx_ssl_session_ticket_keys(cf, &conf->ssl, conf->session_ticket_keys) != NGX_OK) { return NGX_CONF_ERROR; } return NGX_CONF_OK; } static char * ngx_mail_ssl_enable(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_mail_ssl_conf_t *scf = conf; char *rv; rv = ngx_conf_set_flag_slot(cf, cmd, conf); if (rv != NGX_CONF_OK) { return rv; } if (scf->enable && (ngx_int_t) scf->starttls > NGX_MAIL_STARTTLS_OFF) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"starttls\" directive conflicts with \"ssl on\""); return NGX_CONF_ERROR; } scf->file = cf->conf_file->file.name.data; scf->line = cf->conf_file->line; return NGX_CONF_OK; } static char * ngx_mail_ssl_starttls(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_mail_ssl_conf_t *scf = conf; char *rv; rv = ngx_conf_set_enum_slot(cf, cmd, conf); if (rv != NGX_CONF_OK) { return rv; } if (scf->enable == 1 && (ngx_int_t) scf->starttls > NGX_MAIL_STARTTLS_OFF) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"ssl\" directive conflicts with \"starttls\""); return NGX_CONF_ERROR; } scf->file = cf->conf_file->file.name.data; scf->line = cf->conf_file->line; return NGX_CONF_OK; } static char * ngx_mail_ssl_password_file(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_mail_ssl_conf_t *scf = conf; ngx_str_t *value; if (scf->passwords != NGX_CONF_UNSET_PTR) { return "is duplicate"; } value = cf->args->elts; scf->passwords = ngx_ssl_read_password_file(cf, &value[1]); if (scf->passwords == NULL) { return NGX_CONF_ERROR; } return NGX_CONF_OK; } static char * ngx_mail_ssl_session_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_mail_ssl_conf_t *scf = conf; size_t len; ngx_str_t *value, name, size; ngx_int_t n; ngx_uint_t i, j; value = cf->args->elts; for (i = 1; i < cf->args->nelts; i++) { if (ngx_strcmp(value[i].data, "off") == 0) { scf->builtin_session_cache = NGX_SSL_NO_SCACHE; continue; } if (ngx_strcmp(value[i].data, "none") == 0) { scf->builtin_session_cache = NGX_SSL_NONE_SCACHE; continue; } if (ngx_strcmp(value[i].data, "builtin") == 0) { scf->builtin_session_cache = NGX_SSL_DFLT_BUILTIN_SCACHE; continue; } if (value[i].len > sizeof("builtin:") - 1 && ngx_strncmp(value[i].data, "builtin:", sizeof("builtin:") - 1) == 0) { n = ngx_atoi(value[i].data + sizeof("builtin:") - 1, value[i].len - (sizeof("builtin:") - 1)); if (n == NGX_ERROR) { goto invalid; } scf->builtin_session_cache = n; continue; } if (value[i].len > sizeof("shared:") - 1 && ngx_strncmp(value[i].data, "shared:", sizeof("shared:") - 1) == 0) { len = 0; for (j = sizeof("shared:") - 1; j < value[i].len; j++) { if (value[i].data[j] == ':') { break; } len++; } if (len == 0) { goto invalid; } name.len = len; name.data = value[i].data + sizeof("shared:") - 1; size.len = value[i].len - j - 1; size.data = name.data + len + 1; n = ngx_parse_size(&size); if (n == NGX_ERROR) { goto invalid; } if (n < (ngx_int_t) (8 * ngx_pagesize)) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "session cache \"%V\" is too small", &value[i]); return NGX_CONF_ERROR; } scf->shm_zone = ngx_shared_memory_add(cf, &name, n, &ngx_mail_ssl_module); if (scf->shm_zone == NULL) { return NGX_CONF_ERROR; } scf->shm_zone->init = ngx_ssl_session_cache_init; continue; } goto invalid; } if (scf->shm_zone && scf->builtin_session_cache == NGX_CONF_UNSET) { scf->builtin_session_cache = NGX_SSL_NO_BUILTIN_SCACHE; } return NGX_CONF_OK; invalid: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid session cache \"%V\"", &value[i]); return NGX_CONF_ERROR; }