diff options
Diffstat (limited to 'ext/zip/lib/zip_source_pkware.c')
| -rw-r--r-- | ext/zip/lib/zip_source_pkware.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/ext/zip/lib/zip_source_pkware.c b/ext/zip/lib/zip_source_pkware.c new file mode 100644 index 000000000..83b5cc5ad --- /dev/null +++ b/ext/zip/lib/zip_source_pkware.c @@ -0,0 +1,241 @@ +/* + zip_source_pkware.c -- Traditional PKWARE de/encryption routines + Copyright (C) 2009 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 { + int e[2]; + + zip_uint32_t key[3]; +}; + +#define HEADERLEN 12 +#define KEY0 305419896 +#define KEY1 591751049 +#define KEY2 878082192 + +static const uLongf *crc = NULL; + +#define CRC32(c, b) (crc[((c) ^ (b)) & 0xff] ^ ((c) >> 8)) + + + +static void decrypt(struct trad_pkware *, zip_uint8_t *, + const zip_uint8_t *, zip_uint64_t, int); +static int decrypt_header(struct zip_source *, struct trad_pkware *); +static zip_int64_t pkware_decrypt(struct zip_source *, void *, void *, + zip_uint64_t, enum zip_source_cmd); +static void pkware_free(struct trad_pkware *); + + + +ZIP_EXTERN(struct zip_source *) +zip_source_pkware(struct zip *za, struct zip_source *src, + zip_uint16_t em, int flags, const char *password) +{ + struct trad_pkware *ctx; + struct zip_source *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 (crc == NULL) + crc = get_crc_table(); + + if ((ctx=(struct trad_pkware *)malloc(sizeof(*ctx))) == NULL) { + _zip_error_set(&za->error, ZIP_ER_MEMORY, 0); + return NULL; + } + + ctx->e[0] = ctx->e[1] = 0; + + ctx->key[0] = KEY0; + ctx->key[1] = KEY1; + ctx->key[2] = KEY2; + decrypt(ctx, NULL, (const zip_uint8_t *)password, strlen(password), 1); + + if ((s2=zip_source_layered(za, src, pkware_decrypt, ctx)) == NULL) { + pkware_free(ctx); + return NULL; + } + + return s2; +} + + + +static void +decrypt(struct trad_pkware *ctx, zip_uint8_t *out, const zip_uint8_t *in, + zip_uint64_t len, int update_only) +{ + zip_uint16_t tmp; + zip_uint64_t i; + Bytef b; + + for (i=0; i<len; i++) { + b = in[i]; + + if (!update_only) { + /* decrypt next byte */ + tmp = ctx->key[2] | 2; + tmp = (tmp * (tmp ^ 1)) >> 8; + b ^= tmp; + } + + /* store cleartext */ + if (out) + out[i] = b; + + /* update keys */ + ctx->key[0] = CRC32(ctx->key[0], b); + ctx->key[1] = (ctx->key[1] + (ctx->key[0] & 0xff)) * 134775813 + 1; + b = ctx->key[1] >> 24; + ctx->key[2] = CRC32(ctx->key[2], b); + } +} + + + +static int +decrypt_header(struct zip_source *src, struct trad_pkware *ctx) +{ + zip_uint8_t header[HEADERLEN]; + struct zip_stat st; + zip_int64_t n; + unsigned short dostime, dosdate; + + if ((n=zip_source_read(src, header, HEADERLEN)) < 0) { + zip_source_error(src, ctx->e, ctx->e+1); + return -1; + } + + if (n != HEADERLEN) { + ctx->e[0] = ZIP_ER_EOF; + ctx->e[1] = 0; + return -1; + } + + decrypt(ctx, header, header, HEADERLEN, 0); + + if (zip_source_stat(src, &st) < 0) { + /* stat failed, skip password validation */ + return 0; + } + + _zip_u2d_time(st.mtime, &dostime, &dosdate); + + if (header[HEADERLEN-1] != st.crc>>24 + && header[HEADERLEN-1] != dostime>>8) { + ctx->e[0] = ZIP_ER_WRONGPASSWD; + ctx->e[1] = 0; + return -1; + } + + return 0; +} + + + +static zip_int64_t +pkware_decrypt(struct zip_source *src, void *ud, void *data, + zip_uint64_t len, enum zip_source_cmd cmd) +{ + struct trad_pkware *ctx; + zip_int64_t n; + + ctx = (struct trad_pkware *)ud; + + switch (cmd) { + case ZIP_SOURCE_OPEN: + if (decrypt_header(src, ctx) < 0) + return -1; + return 0; + + case ZIP_SOURCE_READ: + if ((n=zip_source_read(src, data, len)) < 0) + return ZIP_SOURCE_ERR_LOWER; + + decrypt(ud, (zip_uint8_t *)data, (zip_uint8_t *)data, (zip_uint64_t)n, + 0); + return n; + + case ZIP_SOURCE_CLOSE: + return 0; + + case ZIP_SOURCE_STAT: + { + struct zip_stat *st; + + st = (struct zip_stat *)data; + + st->encryption_method = ZIP_EM_NONE; + st->valid |= ZIP_STAT_ENCRYPTION_METHOD; + /* XXX: deduce HEADERLEN from size for uncompressed */ + if (st->valid & ZIP_STAT_COMP_SIZE) + st->comp_size -= HEADERLEN; + } + return 0; + + case ZIP_SOURCE_ERROR: + memcpy(data, ctx->e, sizeof(int)*2); + return sizeof(int)*2; + + case ZIP_SOURCE_FREE: + pkware_free(ctx); + return 0; + + default: + ctx->e[0] = ZIP_ER_INVAL; + ctx->e[1] = 0; + return -1; + } +} + + + +static void +pkware_free(struct trad_pkware *ctx) +{ + free(ctx); +} |