From 76f83f0db23846e254d940ec7fe141010077eb88 Mon Sep 17 00:00:00 2001 From: Daniel Stenberg Date: Fri, 24 Jan 2025 11:13:24 +0100 Subject: [PATCH] content_encoding: drop support for zlib before 1.2.0.4 zlib 1.2.0.4 was released on 10 August 2003 Closes #16079 Conflict:context adapt Reference:https://github.com/curl/curl/commit/76f83f0db23846e254d940ec7 --- docs/INTERNALS.md | 2 +- lib/content_encoding.c | 232 ++--------------------------------------- 2 files changed, 8 insertions(+), 226 deletions(-) diff --git a/docs/INTERNALS.md b/docs/INTERNALS.md index d7513a8..f8aba15 100644 --- a/docs/INTERNALS.md +++ b/docs/INTERNALS.md @@ -20,7 +20,7 @@ versions of libs and build tools. - OpenSSL 0.9.7 - GnuTLS 3.1.10 - - zlib 1.1.4 + - zlib 1.2.0.4 - libssh2 1.0 - c-ares 1.16.0 - libidn2 2.0.0 diff --git a/lib/content_encoding.c b/lib/content_encoding.c index be7c075..7fc418e 100644 --- a/lib/content_encoding.c +++ b/lib/content_encoding.c @@ -65,31 +65,13 @@ #define DSIZ CURL_MAX_WRITE_SIZE /* buffer size for decompressed data */ - #ifdef HAVE_LIBZ -/* Comment this out if zlib is always going to be at least ver. 1.2.0.4 - (doing so will reduce code size slightly). */ -#define OLD_ZLIB_SUPPORT 1 - -#define GZIP_MAGIC_0 0x1f -#define GZIP_MAGIC_1 0x8b - -/* gzip flag byte */ -#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ -#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */ -#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ -#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ -#define COMMENT 0x10 /* bit 4 set: file comment present */ -#define RESERVED 0xE0 /* bits 5..7: reserved */ - typedef enum { ZLIB_UNINIT, /* uninitialized */ ZLIB_INIT, /* initialized */ ZLIB_INFLATING, /* inflating started. */ ZLIB_EXTERNAL_TRAILER, /* reading external trailer */ - ZLIB_GZIP_HEADER, /* reading gzip header */ - ZLIB_GZIP_INFLATING, /* inflating gzip stream */ ZLIB_INIT_GZIP /* initialized in transparent gzip mode */ } zlibInitState; @@ -134,9 +116,6 @@ static CURLcode exit_zlib(struct Curl_easy *data, z_stream *z, zlibInitState *zlib_init, CURLcode result) { - if(*zlib_init == ZLIB_GZIP_HEADER) - Curl_safefree(z->next_in); - if(*zlib_init != ZLIB_UNINIT) { if(inflateEnd(z) != Z_OK && result == CURLE_OK) result = process_zlib_error(data, z); @@ -185,8 +164,7 @@ static CURLcode inflate_stream(struct Curl_easy *data, /* Check state. */ if(zp->zlib_init != ZLIB_INIT && zp->zlib_init != ZLIB_INFLATING && - zp->zlib_init != ZLIB_INIT_GZIP && - zp->zlib_init != ZLIB_GZIP_INFLATING) + zp->zlib_init != ZLIB_INIT_GZIP) return exit_zlib(data, z, &zp->zlib_init, CURLE_WRITE_ERROR); /* Dynamically allocate a buffer for decompression because it's uncommonly @@ -333,114 +311,27 @@ static CURLcode gzip_init_writer(struct Curl_easy *data, { struct zlib_writer *zp = (struct zlib_writer *) writer; z_stream *z = &zp->z; /* zlib state structure */ + const char *v = zlibVersion(); /* Initialize zlib */ z->zalloc = (alloc_func) zalloc_cb; z->zfree = (free_func) zfree_cb; - if(strcmp(zlibVersion(), "1.2.0.4") >= 0) { - /* zlib ver. >= 1.2.0.4 supports transparent gzip decompressing */ + if(strcmp(v, "1.2.0.4") >= 0) { + /* zlib version >= 1.2.0.4 supports transparent gzip decompressing */ if(inflateInit2(z, MAX_WBITS + 32) != Z_OK) { return process_zlib_error(data, z); } zp->zlib_init = ZLIB_INIT_GZIP; /* Transparent gzip decompress state */ } else { - /* we must parse the gzip header and trailer ourselves */ - if(inflateInit2(z, -MAX_WBITS) != Z_OK) { - return process_zlib_error(data, z); - } - zp->trailerlen = 8; /* A CRC-32 and a 32-bit input size (RFC 1952, 2.2) */ - zp->zlib_init = ZLIB_INIT; /* Initial call state */ + failf(data, "too old zlib version: %s", v); + return CURLE_FAILED_INIT; } return CURLE_OK; } -#ifdef OLD_ZLIB_SUPPORT -/* Skip over the gzip header */ -static enum { - GZIP_OK, - GZIP_BAD, - GZIP_UNDERFLOW -} check_gzip_header(unsigned char const *data, ssize_t len, ssize_t *headerlen) -{ - int method, flags; - const ssize_t totallen = len; - - /* The shortest header is 10 bytes */ - if(len < 10) - return GZIP_UNDERFLOW; - - if((data[0] != GZIP_MAGIC_0) || (data[1] != GZIP_MAGIC_1)) - return GZIP_BAD; - - method = data[2]; - flags = data[3]; - - if(method != Z_DEFLATED || (flags & RESERVED) != 0) { - /* Can't handle this compression method or unknown flag */ - return GZIP_BAD; - } - - /* Skip over time, xflags, OS code and all previous bytes */ - len -= 10; - data += 10; - - if(flags & EXTRA_FIELD) { - ssize_t extra_len; - - if(len < 2) - return GZIP_UNDERFLOW; - - extra_len = (data[1] << 8) | data[0]; - - if(len < (extra_len + 2)) - return GZIP_UNDERFLOW; - - len -= (extra_len + 2); - data += (extra_len + 2); - } - - if(flags & ORIG_NAME) { - /* Skip over NUL-terminated file name */ - while(len && *data) { - --len; - ++data; - } - if(!len || *data) - return GZIP_UNDERFLOW; - - /* Skip over the NUL */ - --len; - ++data; - } - - if(flags & COMMENT) { - /* Skip over NUL-terminated comment */ - while(len && *data) { - --len; - ++data; - } - if(!len || *data) - return GZIP_UNDERFLOW; - - /* Skip over the NUL */ - --len; - } - - if(flags & HEAD_CRC) { - if(len < 2) - return GZIP_UNDERFLOW; - - len -= 2; - } - - *headerlen = totallen - len; - return GZIP_OK; -} -#endif - static CURLcode gzip_unencode_write(struct Curl_easy *data, struct contenc_writer *writer, const char *buf, size_t nbytes) @@ -456,117 +347,8 @@ static CURLcode gzip_unencode_write(struct Curl_easy *data, return inflate_stream(data, writer, ZLIB_INIT_GZIP); } -#ifndef OLD_ZLIB_SUPPORT - /* Support for old zlib versions is compiled away and we are running with - an old version, so return an error. */ + /* We are running with an old version: return error. */ return exit_zlib(data, z, &zp->zlib_init, CURLE_WRITE_ERROR); - -#else - /* This next mess is to get around the potential case where there isn't - * enough data passed in to skip over the gzip header. If that happens, we - * malloc a block and copy what we have then wait for the next call. If - * there still isn't enough (this is definitely a worst-case scenario), we - * make the block bigger, copy the next part in and keep waiting. - * - * This is only required with zlib versions < 1.2.0.4 as newer versions - * can handle the gzip header themselves. - */ - - switch(zp->zlib_init) { - /* Skip over gzip header? */ - case ZLIB_INIT: - { - /* Initial call state */ - ssize_t hlen; - - switch(check_gzip_header((unsigned char *) buf, nbytes, &hlen)) { - case GZIP_OK: - z->next_in = (Bytef *) buf + hlen; - z->avail_in = (uInt) (nbytes - hlen); - zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */ - break; - - case GZIP_UNDERFLOW: - /* We need more data so we can find the end of the gzip header. It's - * possible that the memory block we malloc here will never be freed if - * the transfer abruptly aborts after this point. Since it's unlikely - * that circumstances will be right for this code path to be followed in - * the first place, and it's even more unlikely for a transfer to fail - * immediately afterwards, it should seldom be a problem. - */ - z->avail_in = (uInt) nbytes; - z->next_in = malloc(z->avail_in); - if(!z->next_in) { - return exit_zlib(data, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY); - } - memcpy(z->next_in, buf, z->avail_in); - zp->zlib_init = ZLIB_GZIP_HEADER; /* Need more gzip header data state */ - /* We don't have any data to inflate yet */ - return CURLE_OK; - - case GZIP_BAD: - default: - return exit_zlib(data, z, &zp->zlib_init, process_zlib_error(data, z)); - } - - } - break; - - case ZLIB_GZIP_HEADER: - { - /* Need more gzip header data state */ - ssize_t hlen; - z->avail_in += (uInt) nbytes; - z->next_in = Curl_saferealloc(z->next_in, z->avail_in); - if(!z->next_in) { - return exit_zlib(data, z, &zp->zlib_init, CURLE_OUT_OF_MEMORY); - } - /* Append the new block of data to the previous one */ - memcpy(z->next_in + z->avail_in - nbytes, buf, nbytes); - - switch(check_gzip_header(z->next_in, z->avail_in, &hlen)) { - case GZIP_OK: - /* This is the zlib stream data */ - free(z->next_in); - /* Don't point into the malloced block since we just freed it */ - z->next_in = (Bytef *) buf + hlen + nbytes - z->avail_in; - z->avail_in = (uInt) (z->avail_in - hlen); - zp->zlib_init = ZLIB_GZIP_INFLATING; /* Inflating stream state */ - break; - - case GZIP_UNDERFLOW: - /* We still don't have any data to inflate! */ - return CURLE_OK; - - case GZIP_BAD: - default: - return exit_zlib(data, z, &zp->zlib_init, process_zlib_error(data, z)); - } - - } - break; - - case ZLIB_EXTERNAL_TRAILER: - z->next_in = (Bytef *) buf; - z->avail_in = (uInt) nbytes; - return process_trailer(data, zp); - - case ZLIB_GZIP_INFLATING: - default: - /* Inflating stream state */ - z->next_in = (Bytef *) buf; - z->avail_in = (uInt) nbytes; - break; - } - - if(z->avail_in == 0) { - /* We don't have any data to inflate; wait until next time */ - return CURLE_OK; - } - - /* We've parsed the header, now uncompress the data */ - return inflate_stream(data, writer, ZLIB_GZIP_INFLATING); -#endif } static void gzip_close_writer(struct Curl_easy *data,