Mercurial > hg > nginx
view src/mail/ngx_mail_ssl_module.c @ 7839:3974f4e56a4e
Mail: fixed s->arg_start clearing on invalid IMAP commands.
Previously, s->arg_start was left intact after invalid IMAP commands,
and this might result in an argument incorrectly added to the following
command. Similarly, s->backslash was left intact as well, leading
to unneeded backslash removal.
For example (LFs from the client are explicitly shown as "<LF>"):
S: * OK IMAP4 ready
C: a01 login "\<LF>
S: a01 BAD invalid command
C: a0000000000\2 authenticate <LF>
S: a00000000002 aBAD invalid command
The backslash followed by LF generates invalid command with s->arg_start
and s->backslash set, the following command incorrectly treats anything
from the old s->arg_start to the space after the command as an argument,
and removes the backslash from the tag. If there is no space, s->arg_end
will be NULL.
Both things seem to be harmless though. In particular:
- This can be used to provide an incorrect argument to a command without
arguments. The only command which seems to look at the single argument
is AUTHENTICATE, and it checks the argument length before trying to
access it.
- Backslash removal uses the "end" pointer, and stops due to "src < end"
condition instead of scanning all the process memory if s->arg_end is
NULL (and arg[0].len is huge).
- There should be no backslashes in unquoted strings.
An obvious fix is to clear s->arg_start and s->backslash on invalid commands,
similarly to how it is done in POP3 parsing (added in 810:e3aa8f305d21) and
SMTP parsing.
This, however, makes it clear that s->arg_start handling in the "done"
label is wrong: s->arg_start cannot be legitimately set there, as it
is expected to be cleared in all possible cases when the "done" label is
reached. The relevant code is dead and will be removed by the following
change.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Wed, 19 May 2021 03:13:20 +0300 |
| parents | 7ce28b4cc57e |
| children | 419c066cb710 |
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 char *ngx_mail_ssl_conf_command_check(ngx_conf_t *cf, void *post, void *data); 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_conf_deprecated_t ngx_mail_ssl_deprecated = { ngx_conf_deprecated, "ssl", "listen ... ssl" }; static ngx_conf_post_t ngx_mail_ssl_conf_command_post = { ngx_mail_ssl_conf_command_check }; 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), &ngx_mail_ssl_deprecated }, { 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_string("ssl_conf_command"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_TAKE2, ngx_conf_set_keyval_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_ssl_conf_t, conf_commands), &ngx_mail_ssl_conf_command_post }, 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->listen = 0; * 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->conf_commands = 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); ngx_conf_merge_ptr_value(conf->conf_commands, prev->conf_commands, NULL); conf->ssl.log = cf->log; if (conf->listen) { mode = "listen ... ssl"; } else if (conf->enable) { mode = "ssl"; } else if (conf->starttls != NGX_MAIL_STARTTLS_OFF) { mode = "starttls"; } else { return NGX_CONF_OK; } if (conf->file == NULL) { conf->file = prev->file; conf->line = prev->line; } 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 \"%s\" directive in %s:%ui", ((ngx_str_t *) conf->certificates->elts) + conf->certificates->nelts - 1, mode, conf->file, conf->line); 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) { ngx_ssl_cleanup_ctx(&conf->ssl); 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_verify_client"); 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->certificates, 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; } if (ngx_ssl_conf_commands(cf, &conf->ssl, conf->conf_commands) != 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; } if (!scf->listen) { 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; } if (!scf->listen) { 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; } static char * ngx_mail_ssl_conf_command_check(ngx_conf_t *cf, void *post, void *data) { #ifndef SSL_CONF_FLAG_FILE return "is not supported on this platform"; #else return NGX_CONF_OK; #endif }