Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_chunked_filter_module.c @ 8531:41f4bd4c51f1
Disabled control characters and space in header names.
Control characters (0x00-0x1f, 0x7f), space, and colon were never allowed in
header names. The only somewhat valid use is header continuation which nginx
never supported and which is explicitly obsolete by RFC 7230.
Previously, such headers were considered invalid and were ignored by default
(as per ignore_invalid_headers directive). With this change, such headers
are unconditionally rejected.
It is expected to make nginx more resilient to various attacks, in particular,
with ignore_invalid_headers switched off (which is inherently unsecure, though
nevertheless sometimes used in the wild).
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 28 Jun 2021 18:01:18 +0300 |
parents | 1b068a4e82d8 |
children | 46e3542d51b3 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_chain_t *free; ngx_chain_t *busy; } ngx_http_chunked_filter_ctx_t; static ngx_int_t ngx_http_chunked_filter_init(ngx_conf_t *cf); static ngx_chain_t *ngx_http_chunked_create_trailers(ngx_http_request_t *r, ngx_http_chunked_filter_ctx_t *ctx); static ngx_http_module_t ngx_http_chunked_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_chunked_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_chunked_filter_module = { NGX_MODULE_V1, &ngx_http_chunked_filter_module_ctx, /* module context */ NULL, /* module directives */ NGX_HTTP_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_http_output_header_filter_pt ngx_http_next_header_filter; static ngx_http_output_body_filter_pt ngx_http_next_body_filter; static ngx_int_t ngx_http_chunked_header_filter(ngx_http_request_t *r) { ngx_http_core_loc_conf_t *clcf; ngx_http_chunked_filter_ctx_t *ctx; if (r->headers_out.status == NGX_HTTP_NOT_MODIFIED || r->headers_out.status == NGX_HTTP_NO_CONTENT || r->headers_out.status < NGX_HTTP_OK || r != r->main || r->method == NGX_HTTP_HEAD) { return ngx_http_next_header_filter(r); } if (r->headers_out.content_length_n == -1 || r->expect_trailers) { clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (r->http_version >= NGX_HTTP_VERSION_11 && clcf->chunked_transfer_encoding) { if (r->expect_trailers) { ngx_http_clear_content_length(r); } r->chunked = 1; ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_filter_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_http_set_ctx(r, ctx, ngx_http_chunked_filter_module); } else if (r->headers_out.content_length_n == -1) { r->keepalive = 0; } } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_chunked_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { u_char *chunk; off_t size; ngx_int_t rc; ngx_buf_t *b; ngx_chain_t *out, *cl, *tl, **ll; ngx_http_chunked_filter_ctx_t *ctx; if (in == NULL || !r->chunked || r->header_only) { return ngx_http_next_body_filter(r, in); } ctx = ngx_http_get_module_ctx(r, ngx_http_chunked_filter_module); out = NULL; ll = &out; size = 0; cl = in; for ( ;; ) { ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http chunk: %O", ngx_buf_size(cl->buf)); size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->sync || ngx_buf_in_memory(cl->buf) || cl->buf->in_file) { tl = ngx_alloc_chain_link(r->pool); if (tl == NULL) { return NGX_ERROR; } tl->buf = cl->buf; *ll = tl; ll = &tl->next; } if (cl->next == NULL) { break; } cl = cl->next; } if (size) { tl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (tl == NULL) { return NGX_ERROR; } b = tl->buf; chunk = b->start; if (chunk == NULL) { /* the "0000000000000000" is 64-bit hexadecimal string */ chunk = ngx_palloc(r->pool, sizeof("0000000000000000" CRLF) - 1); if (chunk == NULL) { return NGX_ERROR; } b->start = chunk; b->end = chunk + sizeof("0000000000000000" CRLF) - 1; } b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module; b->memory = 0; b->temporary = 1; b->pos = chunk; b->last = ngx_sprintf(chunk, "%xO" CRLF, size); tl->next = out; out = tl; } if (cl->buf->last_buf) { tl = ngx_http_chunked_create_trailers(r, ctx); if (tl == NULL) { return NGX_ERROR; } cl->buf->last_buf = 0; *ll = tl; if (size == 0) { tl->buf->pos += 2; } } else if (size > 0) { tl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (tl == NULL) { return NGX_ERROR; } b = tl->buf; b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module; b->temporary = 0; b->memory = 1; b->pos = (u_char *) CRLF; b->last = b->pos + 2; *ll = tl; } else { *ll = NULL; } rc = ngx_http_next_body_filter(r, out); ngx_chain_update_chains(r->pool, &ctx->free, &ctx->busy, &out, (ngx_buf_tag_t) &ngx_http_chunked_filter_module); return rc; } static ngx_chain_t * ngx_http_chunked_create_trailers(ngx_http_request_t *r, ngx_http_chunked_filter_ctx_t *ctx) { size_t len; ngx_buf_t *b; ngx_uint_t i; ngx_chain_t *cl; ngx_list_part_t *part; ngx_table_elt_t *header; len = 0; part = &r->headers_out.trailers.part; header = part->elts; for (i = 0; /* void */; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; header = part->elts; i = 0; } if (header[i].hash == 0) { continue; } len += header[i].key.len + sizeof(": ") - 1 + header[i].value.len + sizeof(CRLF) - 1; } cl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (cl == NULL) { return NULL; } b = cl->buf; b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module; b->temporary = 0; b->memory = 1; b->last_buf = 1; if (len == 0) { b->pos = (u_char *) CRLF "0" CRLF CRLF; b->last = b->pos + sizeof(CRLF "0" CRLF CRLF) - 1; return cl; } len += sizeof(CRLF "0" CRLF CRLF) - 1; b->pos = ngx_palloc(r->pool, len); if (b->pos == NULL) { return NULL; } b->last = b->pos; *b->last++ = CR; *b->last++ = LF; *b->last++ = '0'; *b->last++ = CR; *b->last++ = LF; part = &r->headers_out.trailers.part; header = part->elts; for (i = 0; /* void */; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; header = part->elts; i = 0; } if (header[i].hash == 0) { continue; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http trailer: \"%V: %V\"", &header[i].key, &header[i].value); b->last = ngx_copy(b->last, header[i].key.data, header[i].key.len); *b->last++ = ':'; *b->last++ = ' '; b->last = ngx_copy(b->last, header[i].value.data, header[i].value.len); *b->last++ = CR; *b->last++ = LF; } *b->last++ = CR; *b->last++ = LF; return cl; } static ngx_int_t ngx_http_chunked_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_chunked_header_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_chunked_body_filter; return NGX_OK; }