diff options
Diffstat (limited to 'src/Common/libzip/zip_source_pkware_decode.c')
| -rw-r--r-- | src/Common/libzip/zip_source_pkware_decode.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/src/Common/libzip/zip_source_pkware_decode.c b/src/Common/libzip/zip_source_pkware_decode.c new file mode 100644 index 00000000..c85b590c --- /dev/null +++ b/src/Common/libzip/zip_source_pkware_decode.c @@ -0,0 +1,222 @@ +/* + zip_source_pkware_decode.c -- Traditional PKWARE decryption 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 <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 <string.h> + +#include "zipint.h" + +struct trad_pkware { + char *password; + zip_pkware_keys_t keys; + zip_error_t error; +}; + + +static int decrypt_header(zip_source_t *, struct trad_pkware *); +static zip_int64_t pkware_decrypt(zip_source_t *, void *, void *, zip_uint64_t, zip_source_cmd_t); +static struct trad_pkware *trad_pkware_new(const char *password, zip_error_t *error); +static void trad_pkware_free(struct trad_pkware *); + + +zip_source_t * +zip_source_pkware_decode(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_decrypt, ctx)) == NULL) { + trad_pkware_free(ctx); + return NULL; + } + + return s2; +} + + +static int +decrypt_header(zip_source_t *src, struct trad_pkware *ctx) { + zip_uint8_t header[ZIP_CRYPTO_PKWARE_HEADERLEN]; + struct zip_stat st; + zip_int64_t n; + bool ok; + + if ((n = zip_source_read(src, header, ZIP_CRYPTO_PKWARE_HEADERLEN)) < 0) { + _zip_error_set_from_source(&ctx->error, src); + return -1; + } + + if (n != ZIP_CRYPTO_PKWARE_HEADERLEN) { + zip_error_set(&ctx->error, ZIP_ER_EOF, 0); + return -1; + } + + _zip_pkware_decrypt(&ctx->keys, header, header, ZIP_CRYPTO_PKWARE_HEADERLEN); + + if (zip_source_stat(src, &st)) { + /* stat failed, skip password validation */ + return 0; + } + + /* password verification - two ways: + * mtime - InfoZIP way, to avoid computing complete CRC before encrypting data + * CRC - old PKWare way + */ + + ok = false; + + if (st.valid & ZIP_STAT_MTIME) { + unsigned short dostime, dosdate; + _zip_u2d_time(st.mtime, &dostime, &dosdate); + if (header[ZIP_CRYPTO_PKWARE_HEADERLEN - 1] == dostime >> 8) { + ok = true; + } + } + + if (st.valid & ZIP_STAT_CRC) { + if (header[ZIP_CRYPTO_PKWARE_HEADERLEN - 1] == st.crc >> 24) { + ok = true; + } + } + + if (!ok && ((st.valid & (ZIP_STAT_MTIME | ZIP_STAT_CRC)) != 0)) { + zip_error_set(&ctx->error, ZIP_ER_WRONGPASSWD, 0); + return -1; + } + + return 0; +} + + +static zip_int64_t +pkware_decrypt(zip_source_t *src, void *ud, void *data, zip_uint64_t len, zip_source_cmd_t cmd) { + struct trad_pkware *ctx; + zip_int64_t n; + + ctx = (struct trad_pkware *)ud; + + switch (cmd) { + case ZIP_SOURCE_OPEN: + _zip_pkware_keys_reset(&ctx->keys); + _zip_pkware_decrypt(&ctx->keys, NULL, (const zip_uint8_t *)ctx->password, strlen(ctx->password)); + if (decrypt_header(src, ctx) < 0) { + return -1; + } + return 0; + + case ZIP_SOURCE_READ: + if ((n = zip_source_read(src, data, len)) < 0) { + _zip_error_set_from_source(&ctx->error, src); + return -1; + } + + _zip_pkware_decrypt(&ctx->keys, (zip_uint8_t *)data, (zip_uint8_t *)data, (zip_uint64_t)n); + return n; + + case ZIP_SOURCE_CLOSE: + return 0; + + case ZIP_SOURCE_STAT: { + zip_stat_t *st; + + st = (zip_stat_t *)data; + + st->encryption_method = ZIP_EM_NONE; + st->valid |= ZIP_STAT_ENCRYPTION_METHOD; + if (st->valid & ZIP_STAT_COMP_SIZE) { + st->comp_size -= ZIP_CRYPTO_PKWARE_HEADERLEN; + } + + 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, -1); + + case ZIP_SOURCE_ERROR: + return zip_error_to_data(&ctx->error, data, len); + + case ZIP_SOURCE_FREE: + trad_pkware_free(ctx); + return 0; + + default: + zip_error_set(&ctx->error, ZIP_ER_INVAL, 0); + return -1; + } +} + + +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; + } + + zip_error_init(&ctx->error); + + return ctx; +} + + +static void +trad_pkware_free(struct trad_pkware *ctx) { + if (ctx == NULL) { + return; + } + + free(ctx->password); + free(ctx); +} |