Mercurial > hg > nginx-quic
view src/mail/ngx_mail_handler.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 | 7f955d3b9a0d |
children | da0a85e91587 |
line wrap: on
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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> static void ngx_mail_init_session(ngx_connection_t *c); #if (NGX_MAIL_SSL) static void ngx_mail_ssl_init_connection(ngx_ssl_t *ssl, ngx_connection_t *c); static void ngx_mail_ssl_handshake_handler(ngx_connection_t *c); static ngx_int_t ngx_mail_verify_cert(ngx_mail_session_t *s, ngx_connection_t *c); #endif void ngx_mail_init_connection(ngx_connection_t *c) { size_t len; ngx_uint_t i; ngx_mail_port_t *port; struct sockaddr *sa; struct sockaddr_in *sin; ngx_mail_log_ctx_t *ctx; ngx_mail_in_addr_t *addr; ngx_mail_session_t *s; ngx_mail_addr_conf_t *addr_conf; ngx_mail_core_srv_conf_t *cscf; u_char text[NGX_SOCKADDR_STRLEN]; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; ngx_mail_in6_addr_t *addr6; #endif /* find the server configuration for the address:port */ port = c->listening->servers; if (port->naddrs > 1) { /* * There are several addresses on this port and one of them * is the "*:port" wildcard so getsockname() is needed to determine * the server address. * * AcceptEx() already gave this address. */ if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } sa = c->local_sockaddr; switch (sa->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) sa; addr6 = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (ngx_memcmp(&addr6[i].addr6, &sin6->sin6_addr, 16) == 0) { break; } } addr_conf = &addr6[i].conf; break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) sa; addr = port->addrs; /* the last address is "*" */ for (i = 0; i < port->naddrs - 1; i++) { if (addr[i].addr == sin->sin_addr.s_addr) { break; } } addr_conf = &addr[i].conf; break; } } else { switch (c->local_sockaddr->sa_family) { #if (NGX_HAVE_INET6) case AF_INET6: addr6 = port->addrs; addr_conf = &addr6[0].conf; break; #endif default: /* AF_INET */ addr = port->addrs; addr_conf = &addr[0].conf; break; } } s = ngx_pcalloc(c->pool, sizeof(ngx_mail_session_t)); if (s == NULL) { ngx_mail_close_connection(c); return; } s->signature = NGX_MAIL_MODULE; s->main_conf = addr_conf->ctx->main_conf; s->srv_conf = addr_conf->ctx->srv_conf; s->addr_text = &addr_conf->addr_text; c->data = s; s->connection = c; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_set_connection_log(c, cscf->error_log); len = ngx_sock_ntop(c->sockaddr, c->socklen, text, NGX_SOCKADDR_STRLEN, 1); ngx_log_error(NGX_LOG_INFO, c->log, 0, "*%uA client %*s connected to %V", c->number, len, text, s->addr_text); ctx = ngx_palloc(c->pool, sizeof(ngx_mail_log_ctx_t)); if (ctx == NULL) { ngx_mail_close_connection(c); return; } ctx->client = &c->addr_text; ctx->session = s; c->log->connection = c->number; c->log->handler = ngx_mail_log_error; c->log->data = ctx; c->log->action = "sending client greeting line"; c->log_error = NGX_ERROR_INFO; #if (NGX_MAIL_SSL) { ngx_mail_ssl_conf_t *sslcf; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (sslcf->enable || addr_conf->ssl) { c->log->action = "SSL handshaking"; ngx_mail_ssl_init_connection(&sslcf->ssl, c); return; } } #endif ngx_mail_init_session(c); } #if (NGX_MAIL_SSL) void ngx_mail_starttls_handler(ngx_event_t *rev) { ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_ssl_conf_t *sslcf; c = rev->data; s = c->data; s->starttls = 1; c->log->action = "in starttls state"; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); ngx_mail_ssl_init_connection(&sslcf->ssl, c); } static void ngx_mail_ssl_init_connection(ngx_ssl_t *ssl, ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; if (ngx_ssl_create_connection(ssl, c, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } if (ngx_ssl_handshake(c) == NGX_AGAIN) { s = c->data; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_add_timer(c->read, cscf->timeout); c->ssl->handler = ngx_mail_ssl_handshake_handler; return; } ngx_mail_ssl_handshake_handler(c); } static void ngx_mail_ssl_handshake_handler(ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; if (c->ssl->handshaked) { s = c->data; if (ngx_mail_verify_cert(s, c) != NGX_OK) { return; } if (s->starttls) { cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); c->read->handler = cscf->protocol->init_protocol; c->write->handler = ngx_mail_send; cscf->protocol->init_protocol(c->read); return; } c->read->ready = 0; ngx_mail_init_session(c); return; } ngx_mail_close_connection(c); } static ngx_int_t ngx_mail_verify_cert(ngx_mail_session_t *s, ngx_connection_t *c) { long rc; X509 *cert; ngx_mail_ssl_conf_t *sslcf; ngx_mail_core_srv_conf_t *cscf; sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (!sslcf->verify) { return NGX_OK; } rc = SSL_get_verify_result(c->ssl->connection); if (rc != X509_V_OK && (sslcf->verify != 3 || !ngx_ssl_verify_error_optional(rc))) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client SSL certificate verify error: (%l:%s)", rc, X509_verify_cert_error_string(rc)); ngx_ssl_remove_cached_session(c->ssl->session_ctx, (SSL_get0_session(c->ssl->connection))); cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->cert_error; s->quit = 1; c->write->handler = ngx_mail_send; ngx_mail_send(s->connection->write); return NGX_ERROR; } if (sslcf->verify == 1) { cert = SSL_get_peer_certificate(c->ssl->connection); if (cert == NULL) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent no required SSL certificate"); ngx_ssl_remove_cached_session(c->ssl->session_ctx, (SSL_get0_session(c->ssl->connection))); cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->no_cert; s->quit = 1; c->write->handler = ngx_mail_send; ngx_mail_send(s->connection->write); return NGX_ERROR; } X509_free(cert); } return NGX_OK; } #endif static void ngx_mail_init_session(ngx_connection_t *c) { ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; s = c->data; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->protocol = cscf->protocol->type; s->ctx = ngx_pcalloc(c->pool, sizeof(void *) * ngx_mail_max_module); if (s->ctx == NULL) { ngx_mail_session_internal_server_error(s); return; } c->write->handler = ngx_mail_send; cscf->protocol->init_session(s, c); } ngx_int_t ngx_mail_salt(ngx_mail_session_t *s, ngx_connection_t *c, ngx_mail_core_srv_conf_t *cscf) { s->salt.data = ngx_pnalloc(c->pool, sizeof(" <18446744073709551616.@>" CRLF) - 1 + NGX_TIME_T_LEN + cscf->server_name.len); if (s->salt.data == NULL) { return NGX_ERROR; } s->salt.len = ngx_sprintf(s->salt.data, "<%ul.%T@%V>" CRLF, ngx_random(), ngx_time(), &cscf->server_name) - s->salt.data; return NGX_OK; } #if (NGX_MAIL_SSL) ngx_int_t ngx_mail_starttls_only(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_mail_ssl_conf_t *sslcf; if (c->ssl) { return 0; } sslcf = ngx_mail_get_module_srv_conf(s, ngx_mail_ssl_module); if (sslcf->starttls == NGX_MAIL_STARTTLS_ONLY) { return 1; } return 0; } #endif ngx_int_t ngx_mail_auth_plain(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { u_char *p, *last; ngx_str_t *arg, plain; arg = s->args.elts; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth plain: \"%V\"", &arg[n]); #endif plain.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (plain.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&plain, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } p = plain.data; last = p + plain.len; while (p < last && *p++) { /* void */ } if (p == last) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid login in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.data = p; while (p < last && *p) { p++; } if (p == last) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid password in AUTH PLAIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.len = p++ - s->login.data; s->passwd.len = last - p; s->passwd.data = p; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth plain: \"%V\" \"%V\"", &s->login, &s->passwd); #endif return NGX_DONE; } ngx_int_t ngx_mail_auth_login_username(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { ngx_str_t *arg; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login username: \"%V\"", &arg[n]); s->login.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (s->login.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&s->login, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH LOGIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login username: \"%V\"", &s->login); return NGX_OK; } ngx_int_t ngx_mail_auth_login_password(ngx_mail_session_t *s, ngx_connection_t *c) { ngx_str_t *arg; arg = s->args.elts; #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login password: \"%V\"", &arg[0]); #endif s->passwd.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[0].len)); if (s->passwd.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&s->passwd, &arg[0]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH LOGIN command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } #if (NGX_DEBUG_MAIL_PASSWD) ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth login password: \"%V\"", &s->passwd); #endif return NGX_DONE; } ngx_int_t ngx_mail_auth_cram_md5_salt(ngx_mail_session_t *s, ngx_connection_t *c, char *prefix, size_t len) { u_char *p; ngx_str_t salt; ngx_uint_t n; p = ngx_pnalloc(c->pool, len + ngx_base64_encoded_length(s->salt.len) + 2); if (p == NULL) { return NGX_ERROR; } salt.data = ngx_cpymem(p, prefix, len); s->salt.len -= 2; ngx_encode_base64(&salt, &s->salt); s->salt.len += 2; n = len + salt.len; p[n++] = CR; p[n++] = LF; s->out.len = n; s->out.data = p; return NGX_OK; } ngx_int_t ngx_mail_auth_cram_md5(ngx_mail_session_t *s, ngx_connection_t *c) { u_char *p, *last; ngx_str_t *arg; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth cram-md5: \"%V\"", &arg[0]); s->login.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[0].len)); if (s->login.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&s->login, &arg[0]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH CRAM-MD5 command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } p = s->login.data; last = p + s->login.len; while (p < last) { if (*p++ == ' ') { s->login.len = p - s->login.data - 1; s->passwd.len = last - p; s->passwd.data = p; break; } } if (s->passwd.len != 32) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid CRAM-MD5 hash in AUTH CRAM-MD5 command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } ngx_log_debug2(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth cram-md5: \"%V\" \"%V\"", &s->login, &s->passwd); s->auth_method = NGX_MAIL_AUTH_CRAM_MD5; return NGX_DONE; } ngx_int_t ngx_mail_auth_external(ngx_mail_session_t *s, ngx_connection_t *c, ngx_uint_t n) { ngx_str_t *arg, external; arg = s->args.elts; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth external: \"%V\"", &arg[n]); external.data = ngx_pnalloc(c->pool, ngx_base64_decoded_length(arg[n].len)); if (external.data == NULL) { return NGX_ERROR; } if (ngx_decode_base64(&external, &arg[n]) != NGX_OK) { ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent invalid base64 encoding in AUTH EXTERNAL command"); return NGX_MAIL_PARSE_INVALID_COMMAND; } s->login.len = external.len; s->login.data = external.data; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "mail auth external: \"%V\"", &s->login); s->auth_method = NGX_MAIL_AUTH_EXTERNAL; return NGX_DONE; } void ngx_mail_send(ngx_event_t *wev) { ngx_int_t n; ngx_connection_t *c; ngx_mail_session_t *s; ngx_mail_core_srv_conf_t *cscf; c = wev->data; s = c->data; if (wev->timedout) { ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out"); c->timedout = 1; ngx_mail_close_connection(c); return; } if (s->out.len == 0) { if (ngx_handle_write_event(c->write, 0) != NGX_OK) { ngx_mail_close_connection(c); } return; } n = c->send(c, s->out.data, s->out.len); if (n > 0) { s->out.data += n; s->out.len -= n; if (s->out.len != 0) { goto again; } if (wev->timer_set) { ngx_del_timer(wev); } if (s->quit) { ngx_mail_close_connection(c); return; } if (s->blocked) { c->read->handler(c->read); } return; } if (n == NGX_ERROR) { ngx_mail_close_connection(c); return; } /* n == NGX_AGAIN */ again: cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); ngx_add_timer(c->write, cscf->timeout); if (ngx_handle_write_event(c->write, 0) != NGX_OK) { ngx_mail_close_connection(c); return; } } ngx_int_t ngx_mail_read_command(ngx_mail_session_t *s, ngx_connection_t *c) { ssize_t n; ngx_int_t rc; ngx_str_t l; ngx_mail_core_srv_conf_t *cscf; n = c->recv(c, s->buffer->last, s->buffer->end - s->buffer->last); if (n == NGX_ERROR || n == 0) { ngx_mail_close_connection(c); return NGX_ERROR; } if (n > 0) { s->buffer->last += n; } if (n == NGX_AGAIN) { if (ngx_handle_read_event(c->read, 0) != NGX_OK) { ngx_mail_session_internal_server_error(s); return NGX_ERROR; } if (s->buffer->pos == s->buffer->last) { return NGX_AGAIN; } } cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); rc = cscf->protocol->parse_command(s); if (rc == NGX_AGAIN) { if (s->buffer->last < s->buffer->end) { return rc; } l.len = s->buffer->last - s->buffer->start; l.data = s->buffer->start; ngx_log_error(NGX_LOG_INFO, c->log, 0, "client sent too long command \"%V\"", &l); s->quit = 1; return NGX_MAIL_PARSE_INVALID_COMMAND; } if (rc == NGX_IMAP_NEXT || rc == NGX_MAIL_PARSE_INVALID_COMMAND) { return rc; } if (rc == NGX_ERROR) { ngx_mail_close_connection(c); return NGX_ERROR; } return NGX_OK; } void ngx_mail_auth(ngx_mail_session_t *s, ngx_connection_t *c) { s->args.nelts = 0; if (s->buffer->pos == s->buffer->last) { s->buffer->pos = s->buffer->start; s->buffer->last = s->buffer->start; } s->state = 0; if (c->read->timer_set) { ngx_del_timer(c->read); } s->login_attempt++; ngx_mail_auth_http_init(s); } void ngx_mail_session_internal_server_error(ngx_mail_session_t *s) { ngx_mail_core_srv_conf_t *cscf; cscf = ngx_mail_get_module_srv_conf(s, ngx_mail_core_module); s->out = cscf->protocol->internal_server_error; s->quit = 1; ngx_mail_send(s->connection->write); } void ngx_mail_close_connection(ngx_connection_t *c) { ngx_pool_t *pool; ngx_log_debug1(NGX_LOG_DEBUG_MAIL, c->log, 0, "close mail connection: %d", c->fd); #if (NGX_MAIL_SSL) if (c->ssl) { if (ngx_ssl_shutdown(c) == NGX_AGAIN) { c->ssl->handler = ngx_mail_close_connection; return; } } #endif #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, -1); #endif c->destroyed = 1; pool = c->pool; ngx_close_connection(c); ngx_destroy_pool(pool); } u_char * ngx_mail_log_error(ngx_log_t *log, u_char *buf, size_t len) { u_char *p; ngx_mail_session_t *s; ngx_mail_log_ctx_t *ctx; if (log->action) { p = ngx_snprintf(buf, len, " while %s", log->action); len -= p - buf; buf = p; } ctx = log->data; p = ngx_snprintf(buf, len, ", client: %V", ctx->client); len -= p - buf; buf = p; s = ctx->session; if (s == NULL) { return p; } p = ngx_snprintf(buf, len, "%s, server: %V", s->starttls ? " using starttls" : "", s->addr_text); len -= p - buf; buf = p; if (s->login.len == 0) { return p; } p = ngx_snprintf(buf, len, ", login: \"%V\"", &s->login); len -= p - buf; buf = p; if (s->proxy == NULL) { return p; } p = ngx_snprintf(buf, len, ", upstream: %V", s->proxy->upstream.name); return p; }