diff options
Diffstat (limited to 'src/Common/libzip/zip_source_pkware_encode.c')
-rw-r--r-- | src/Common/libzip/zip_source_pkware_encode.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/src/Common/libzip/zip_source_pkware_encode.c b/src/Common/libzip/zip_source_pkware_encode.c new file mode 100644 index 00000000..d89b9f4e --- /dev/null +++ b/src/Common/libzip/zip_source_pkware_encode.c @@ -0,0 +1,271 @@ +/* + zip_source_pkware_encode.c -- Traditional PKWARE encryption routines + Copyright (C) 2009-2020 Dieter Baron and Thomas Klausner + + This file is part of libzip, a library to manipulate ZIP archives. + The authors can be contacted at <info@libzip.org> + + 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 <string.h> + +#include "zipint.h" + +struct trad_pkware { + char *password; + zip_pkware_keys_t keys; + zip_buffer_t *buffer; + bool eof; + bool mtime_set; + time_t mtime; + zip_error_t error; +}; + + +static int encrypt_header(zip_source_t *, struct trad_pkware *); +static zip_int64_t pkware_encrypt(zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t); +static void trad_pkware_free(struct trad_pkware *); +static struct trad_pkware *trad_pkware_new(const char *password, zip_error_t *error); +static void set_mtime(struct trad_pkware* ctx, zip_stat_t* st); + +zip_source_t * +zip_source_pkware_encode(zip_t *za, zip_source_t *src, zip_uint16_t em, int flags, const char *password) { + struct trad_pkware *ctx; + zip_source_t *s2; + + if (password == NULL || src == NULL || em != ZIP_EM_TRAD_PKWARE) { + zip_error_set(&za->error, ZIP_ER_INVAL, 0); + return NULL; + } + if (!(flags & ZIP_CODEC_ENCODE)) { + zip_error_set(&za->error, ZIP_ER_ENCRNOTSUPP, 0); + return NULL; + } + + if ((ctx = trad_pkware_new(password, &za->error)) == NULL) { + return NULL; + } + + if ((s2 = zip_source_layered(za, src, pkware_encrypt, ctx)) == NULL) { + trad_pkware_free(ctx); + return NULL; + } + + return s2; +} + + +static int +encrypt_header(zip_source_t *src, struct trad_pkware *ctx) { + unsigned short dostime, dosdate; + zip_uint8_t *header; + + if (!ctx->mtime_set) { + struct zip_stat st; + if (zip_source_stat(src, &st) != 0) { + zip_error_set_from_source(&ctx->error, src); + return -1; + } + set_mtime(ctx, &st); + } + + _zip_u2d_time(ctx->mtime, &dostime, &dosdate); + + if ((ctx->buffer = _zip_buffer_new(NULL, ZIP_CRYPTO_PKWARE_HEADERLEN)) == NULL) { + zip_error_set(&ctx->error, ZIP_ER_MEMORY, 0); + return -1; + } + + header = _zip_buffer_data(ctx->buffer); + + /* generate header from random bytes and mtime + see appnote.iz, XIII. Decryption, Step 2, last paragraph */ + if (!zip_secure_random(header, ZIP_CRYPTO_PKWARE_HEADERLEN - 1)) { + zip_error_set(&ctx->error, ZIP_ER_INTERNAL, 0); + _zip_buffer_free(ctx->buffer); + ctx->buffer = NULL; + return -1; + } + header[ZIP_CRYPTO_PKWARE_HEADERLEN - 1] = (zip_uint8_t)((dostime >> 8) & 0xff); + + _zip_pkware_encrypt(&ctx->keys, header, header, ZIP_CRYPTO_PKWARE_HEADERLEN); + + return 0; +} + + +static zip_int64_t +pkware_encrypt(zip_source_t *src, void *ud, void *data, zip_uint64_t length, zip_source_cmd_t cmd) { + struct trad_pkware *ctx; + zip_int64_t n; + zip_uint64_t buffer_n; + + ctx = (struct trad_pkware *)ud; + + switch (cmd) { + case ZIP_SOURCE_OPEN: + ctx->eof = false; + + /* initialize keys */ + _zip_pkware_keys_reset(&ctx->keys); + _zip_pkware_encrypt(&ctx->keys, NULL, (const zip_uint8_t *)ctx->password, strlen(ctx->password)); + + if (encrypt_header(src, ctx) < 0) { + return -1; + } + return 0; + + case ZIP_SOURCE_READ: + buffer_n = 0; + + if (ctx->buffer) { + /* write header values to data */ + buffer_n = _zip_buffer_read(ctx->buffer, data, length); + data = (zip_uint8_t *)data + buffer_n; + length -= buffer_n; + + if (_zip_buffer_eof(ctx->buffer)) { + _zip_buffer_free(ctx->buffer); + ctx->buffer = NULL; + } + } + + if (ctx->eof) { + return (zip_int64_t)buffer_n; + } + + if ((n = zip_source_read(src, data, length)) < 0) { + zip_error_set_from_source(&ctx->error, src); + return -1; + } + + _zip_pkware_encrypt(&ctx->keys, (zip_uint8_t *)data, (zip_uint8_t *)data, (zip_uint64_t)n); + + if ((zip_uint64_t)n < length) { + ctx->eof = true; + } + + return (zip_int64_t)buffer_n + n; + + case ZIP_SOURCE_CLOSE: + _zip_buffer_free(ctx->buffer); + ctx->buffer = NULL; + return 0; + + case ZIP_SOURCE_STAT: { + zip_stat_t *st; + + st = (zip_stat_t *)data; + st->encryption_method = ZIP_EM_TRAD_PKWARE; + st->valid |= ZIP_STAT_ENCRYPTION_METHOD; + if (st->valid & ZIP_STAT_COMP_SIZE) { + st->comp_size += ZIP_CRYPTO_PKWARE_HEADERLEN; + } + set_mtime(ctx, st); + st->mtime = ctx->mtime; + st->valid |= ZIP_STAT_MTIME; + + return 0; + } + + case ZIP_SOURCE_GET_FILE_ATTRIBUTES: { + zip_file_attributes_t *attributes = (zip_file_attributes_t *)data; + if (length < sizeof(*attributes)) { + zip_error_set(&ctx->error, ZIP_ER_INVAL, 0); + return -1; + } + attributes->valid |= ZIP_FILE_ATTRIBUTES_VERSION_NEEDED; + attributes->version_needed = 20; + + return 0; + } + + case ZIP_SOURCE_SUPPORTS: + return zip_source_make_command_bitmap(ZIP_SOURCE_OPEN, ZIP_SOURCE_READ, ZIP_SOURCE_CLOSE, ZIP_SOURCE_STAT, ZIP_SOURCE_ERROR, ZIP_SOURCE_FREE, ZIP_SOURCE_GET_FILE_ATTRIBUTES, -1); + + case ZIP_SOURCE_ERROR: + return zip_error_to_data(&ctx->error, data, length); + + case ZIP_SOURCE_FREE: + trad_pkware_free(ctx); + return 0; + + default: + return zip_source_pass_to_lower_layer(src, data, length, cmd); + } +} + + +static struct trad_pkware * +trad_pkware_new(const char *password, zip_error_t *error) { + struct trad_pkware *ctx; + + if ((ctx = (struct trad_pkware *)malloc(sizeof(*ctx))) == NULL) { + zip_error_set(error, ZIP_ER_MEMORY, 0); + return NULL; + } + + if ((ctx->password = strdup(password)) == NULL) { + zip_error_set(error, ZIP_ER_MEMORY, 0); + free(ctx); + return NULL; + } + ctx->buffer = NULL; + ctx->mtime_set = false; + ctx->mtime = 0; + zip_error_init(&ctx->error); + + return ctx; +} + + +static void +trad_pkware_free(struct trad_pkware *ctx) { + if (ctx == NULL) { + return; + } + + free(ctx->password); + _zip_buffer_free(ctx->buffer); + zip_error_fini(&ctx->error); + free(ctx); +} + + +static void set_mtime(struct trad_pkware* ctx, zip_stat_t* st) { + if (!ctx->mtime_set) { + if (st->valid & ZIP_STAT_MTIME) { + ctx->mtime = st->mtime; + } + else { + time(&ctx->mtime); + } + ctx->mtime_set = true; + } +} |