/* zip_source_zip_new.c -- prepare data structures for zip_fopen/zip_source_zip Copyright (C) 2012-2019 Dieter Baron and Thomas Klausner This file is part of libzip, a library to manipulate ZIP archives. The authors can be contacted at <libzip@nih.at> Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. The names of the authors may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include <stdlib.h> #include "zipint.h" static void _zip_file_attributes_from_dirent(zip_file_attributes_t *attributes, zip_dirent_t *de); zip_source_t * _zip_source_zip_new(zip_t *za, zip_t *srcza, zip_uint64_t srcidx, zip_flags_t flags, zip_uint64_t start, zip_uint64_t len, const char *password) { zip_source_t *src, *s2; zip_stat_t st; zip_file_attributes_t attributes; zip_dirent_t *de; bool partial_data, needs_crc, needs_decrypt, needs_decompress; if (za == NULL) { return NULL; } if (srcza == NULL || srcidx >= srcza->nentry) { zip_error_set(&za->error, ZIP_ER_INVAL, 0); return NULL; } if ((flags & ZIP_FL_UNCHANGED) == 0 && (ZIP_ENTRY_DATA_CHANGED(srcza->entry + srcidx) || srcza->entry[srcidx].deleted)) { zip_error_set(&za->error, ZIP_ER_CHANGED, 0); return NULL; } if (zip_stat_index(srcza, srcidx, flags | ZIP_FL_UNCHANGED, &st) < 0) { zip_error_set(&za->error, ZIP_ER_INTERNAL, 0); return NULL; } if (flags & ZIP_FL_ENCRYPTED) { flags |= ZIP_FL_COMPRESSED; } if ((start > 0 || len > 0) && (flags & ZIP_FL_COMPRESSED)) { zip_error_set(&za->error, ZIP_ER_INVAL, 0); return NULL; } /* overflow or past end of file */ if ((start > 0 || len > 0) && (start + len < start || start + len > st.size)) { zip_error_set(&za->error, ZIP_ER_INVAL, 0); return NULL; } if (len == 0) { len = st.size - start; } partial_data = len < st.size; needs_decrypt = ((flags & ZIP_FL_ENCRYPTED) == 0) && (st.encryption_method != ZIP_EM_NONE); needs_decompress = ((flags & ZIP_FL_COMPRESSED) == 0) && (st.comp_method != ZIP_CM_STORE); /* when reading the whole file, check for CRC errors */ needs_crc = ((flags & ZIP_FL_COMPRESSED) == 0 || st.comp_method == ZIP_CM_STORE) && !partial_data; if (needs_decrypt) { if (password == NULL) { password = za->default_password; } if (password == NULL) { zip_error_set(&za->error, ZIP_ER_NOPASSWD, 0); return NULL; } } if ((de = _zip_get_dirent(srcza, srcidx, flags, &za->error)) == NULL) { return NULL; } _zip_file_attributes_from_dirent(&attributes, de); if (st.comp_size == 0) { return zip_source_buffer_with_attributes(za, NULL, 0, 0, &attributes); } if (partial_data && !needs_decrypt && !needs_decompress) { struct zip_stat st2; st2.size = len; st2.comp_size = len; st2.comp_method = ZIP_CM_STORE; st2.mtime = st.mtime; st2.valid = ZIP_STAT_SIZE | ZIP_STAT_COMP_SIZE | ZIP_STAT_COMP_METHOD | ZIP_STAT_MTIME; if ((src = _zip_source_window_new(srcza->src, start, len, &st2, &attributes, srcza, srcidx, &za->error)) == NULL) { return NULL; } } else { if ((src = _zip_source_window_new(srcza->src, 0, st.comp_size, &st, &attributes, srcza, srcidx, &za->error)) == NULL) { return NULL; } } if (_zip_source_set_source_archive(src, srcza) < 0) { zip_source_free(src); return NULL; } /* creating a layered source calls zip_keep() on the lower layer, so we free it */ if (needs_decrypt) { zip_encryption_implementation enc_impl; if ((enc_impl = _zip_get_encryption_implementation(st.encryption_method, ZIP_CODEC_DECODE)) == NULL) { zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0); return NULL; } s2 = enc_impl(za, src, st.encryption_method, 0, password); zip_source_free(src); if (s2 == NULL) { return NULL; } src = s2; } if (needs_decompress) { s2 = zip_source_decompress(za, src, st.comp_method); zip_source_free(src); if (s2 == NULL) { return NULL; } src = s2; } if (needs_crc) { s2 = zip_source_crc(za, src, 1); zip_source_free(src); if (s2 == NULL) { return NULL; } src = s2; } if (partial_data && (needs_decrypt || needs_decompress)) { s2 = zip_source_window(za, src, start, len); zip_source_free(src); if (s2 == NULL) { return NULL; } src = s2; } return src; } static void _zip_file_attributes_from_dirent(zip_file_attributes_t *attributes, zip_dirent_t *de) { zip_file_attributes_init(attributes); attributes->valid = ZIP_FILE_ATTRIBUTES_ASCII | ZIP_FILE_ATTRIBUTES_HOST_SYSTEM | ZIP_FILE_ATTRIBUTES_EXTERNAL_FILE_ATTRIBUTES | ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS; attributes->ascii = de->int_attrib & 1; attributes->host_system = de->version_madeby >> 8; attributes->external_file_attributes = de->ext_attrib; attributes->general_purpose_bit_flags = de->bitflags; attributes->general_purpose_bit_mask = ZIP_FILE_ATTRIBUTES_GENERAL_PURPOSE_BIT_FLAGS_ALLOWED_MASK; }