Mercurial > hg > nginx-quic
view src/mail/ngx_mail_pop3_module.c @ 7977:7731c710796f
Memcached: protect from too long responses.
If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 06 Jul 2020 18:36:17 +0300 |
parents | 03735fef08da |
children | dc955d274130 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #include <ngx_mail.h> #include <ngx_mail_pop3_module.h> static void *ngx_mail_pop3_create_srv_conf(ngx_conf_t *cf); static char *ngx_mail_pop3_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_str_t ngx_mail_pop3_default_capabilities[] = { ngx_string("TOP"), ngx_string("USER"), ngx_string("UIDL"), ngx_null_string }; static ngx_conf_bitmask_t ngx_mail_pop3_auth_methods[] = { { ngx_string("plain"), NGX_MAIL_AUTH_PLAIN_ENABLED }, { ngx_string("apop"), NGX_MAIL_AUTH_APOP_ENABLED }, { ngx_string("cram-md5"), NGX_MAIL_AUTH_CRAM_MD5_ENABLED }, { ngx_string("external"), NGX_MAIL_AUTH_EXTERNAL_ENABLED }, { ngx_null_string, 0 } }; static ngx_str_t ngx_mail_pop3_auth_methods_names[] = { ngx_string("PLAIN"), ngx_string("LOGIN"), ngx_null_string, /* APOP */ ngx_string("CRAM-MD5"), ngx_string("EXTERNAL"), ngx_null_string /* NONE */ }; static ngx_mail_protocol_t ngx_mail_pop3_protocol = { ngx_string("pop3"), { 110, 995, 0, 0 }, NGX_MAIL_POP3_PROTOCOL, ngx_mail_pop3_init_session, ngx_mail_pop3_init_protocol, ngx_mail_pop3_parse_command, ngx_mail_pop3_auth_state, ngx_string("-ERR internal server error" CRLF), ngx_string("-ERR SSL certificate error" CRLF), ngx_string("-ERR No required SSL certificate" CRLF) }; static ngx_command_t ngx_mail_pop3_commands[] = { { ngx_string("pop3_capabilities"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_mail_capabilities, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_pop3_srv_conf_t, capabilities), NULL }, { ngx_string("pop3_auth"), NGX_MAIL_MAIN_CONF|NGX_MAIL_SRV_CONF|NGX_CONF_1MORE, ngx_conf_set_bitmask_slot, NGX_MAIL_SRV_CONF_OFFSET, offsetof(ngx_mail_pop3_srv_conf_t, auth_methods), &ngx_mail_pop3_auth_methods }, ngx_null_command }; static ngx_mail_module_t ngx_mail_pop3_module_ctx = { &ngx_mail_pop3_protocol, /* protocol */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_mail_pop3_create_srv_conf, /* create server configuration */ ngx_mail_pop3_merge_srv_conf /* merge server configuration */ }; ngx_module_t ngx_mail_pop3_module = { NGX_MODULE_V1, &ngx_mail_pop3_module_ctx, /* module context */ ngx_mail_pop3_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 void * ngx_mail_pop3_create_srv_conf(ngx_conf_t *cf) { ngx_mail_pop3_srv_conf_t *pscf; pscf = ngx_pcalloc(cf->pool, sizeof(ngx_mail_pop3_srv_conf_t)); if (pscf == NULL) { return NULL; } if (ngx_array_init(&pscf->capabilities, cf->pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NULL; } return pscf; } static char * ngx_mail_pop3_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_mail_pop3_srv_conf_t *prev = parent; ngx_mail_pop3_srv_conf_t *conf = child; u_char *p; size_t size, stls_only_size; ngx_str_t *c, *d; ngx_uint_t i, m; ngx_conf_merge_bitmask_value(conf->auth_methods, prev->auth_methods, (NGX_CONF_BITMASK_SET |NGX_MAIL_AUTH_PLAIN_ENABLED)); if (conf->auth_methods & NGX_MAIL_AUTH_PLAIN_ENABLED) { conf->auth_methods |= NGX_MAIL_AUTH_LOGIN_ENABLED; } if (conf->capabilities.nelts == 0) { conf->capabilities = prev->capabilities; } if (conf->capabilities.nelts == 0) { for (d = ngx_mail_pop3_default_capabilities; d->len; d++) { c = ngx_array_push(&conf->capabilities); if (c == NULL) { return NGX_CONF_ERROR; } *c = *d; } } size = sizeof("+OK Capability list follows" CRLF) - 1 + sizeof("." CRLF) - 1; stls_only_size = size + sizeof("STLS" CRLF) - 1; c = conf->capabilities.elts; for (i = 0; i < conf->capabilities.nelts; i++) { size += c[i].len + sizeof(CRLF) - 1; if (ngx_strcasecmp(c[i].data, (u_char *) "USER") == 0) { continue; } stls_only_size += c[i].len + sizeof(CRLF) - 1; } size += sizeof("SASL") - 1 + sizeof(CRLF) - 1; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (ngx_mail_pop3_auth_methods_names[i].len == 0) { continue; } if (m & conf->auth_methods) { size += 1 + ngx_mail_pop3_auth_methods_names[i].len; } } p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->capability.len = size; conf->capability.data = p; p = ngx_cpymem(p, "+OK Capability list follows" CRLF, sizeof("+OK Capability list follows" CRLF) - 1); for (i = 0; i < conf->capabilities.nelts; i++) { p = ngx_cpymem(p, c[i].data, c[i].len); *p++ = CR; *p++ = LF; } p = ngx_cpymem(p, "SASL", sizeof("SASL") - 1); for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (ngx_mail_pop3_auth_methods_names[i].len == 0) { continue; } if (m & conf->auth_methods) { *p++ = ' '; p = ngx_cpymem(p, ngx_mail_pop3_auth_methods_names[i].data, ngx_mail_pop3_auth_methods_names[i].len); } } *p++ = CR; *p++ = LF; *p++ = '.'; *p++ = CR; *p = LF; size += sizeof("STLS" CRLF) - 1; p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_capability.len = size; conf->starttls_capability.data = p; p = ngx_cpymem(p, conf->capability.data, conf->capability.len - (sizeof("." CRLF) - 1)); p = ngx_cpymem(p, "STLS" CRLF, sizeof("STLS" CRLF) - 1); *p++ = '.'; *p++ = CR; *p = LF; size = sizeof("+OK methods supported:" CRLF) - 1 + sizeof("." CRLF) - 1; for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (ngx_mail_pop3_auth_methods_names[i].len == 0) { continue; } if (m & conf->auth_methods) { size += ngx_mail_pop3_auth_methods_names[i].len + sizeof(CRLF) - 1; } } p = ngx_pnalloc(cf->pool, size); if (p == NULL) { return NGX_CONF_ERROR; } conf->auth_capability.data = p; conf->auth_capability.len = size; p = ngx_cpymem(p, "+OK methods supported:" CRLF, sizeof("+OK methods supported:" CRLF) - 1); for (m = NGX_MAIL_AUTH_PLAIN_ENABLED, i = 0; m <= NGX_MAIL_AUTH_EXTERNAL_ENABLED; m <<= 1, i++) { if (ngx_mail_pop3_auth_methods_names[i].len == 0) { continue; } if (m & conf->auth_methods) { p = ngx_cpymem(p, ngx_mail_pop3_auth_methods_names[i].data, ngx_mail_pop3_auth_methods_names[i].len); *p++ = CR; *p++ = LF; } } *p++ = '.'; *p++ = CR; *p = LF; p = ngx_pnalloc(cf->pool, stls_only_size); if (p == NULL) { return NGX_CONF_ERROR; } conf->starttls_only_capability.len = stls_only_size; conf->starttls_only_capability.data = p; p = ngx_cpymem(p, "+OK Capability list follows" CRLF, sizeof("+OK Capability list follows" CRLF) - 1); for (i = 0; i < conf->capabilities.nelts; i++) { if (ngx_strcasecmp(c[i].data, (u_char *) "USER") == 0) { continue; } p = ngx_cpymem(p, c[i].data, c[i].len); *p++ = CR; *p++ = LF; } p = ngx_cpymem(p, "STLS" CRLF, sizeof("STLS" CRLF) - 1); *p++ = '.'; *p++ = CR; *p = LF; return NGX_CONF_OK; }