Mercurial > hg > nginx-quic
view src/mail/ngx_mail_pop3_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 | 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; }