lib/zip_source_pkware_encode.c - third_party/libzip - Git at Google

 /*
   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 <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_buffer_t *buffer;
     bool eof;
     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);


 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) {
     struct zip_stat st;
     unsigned short dostime, dosdate;
     zip_uint8_t *header;

     if (zip_source_stat(src, &st) != 0) {
         _zip_error_set_from_source(&ctx->error, src);
         return -1;
     }

     _zip_u2d_time(st.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;
         }

         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:
         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;
     }
     ctx->buffer = NULL;
     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);
 }
	/*
	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 <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_buffer_t *buffer;
	bool eof;
	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);


	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) {
	struct zip_stat st;
	unsigned short dostime, dosdate;
	zip_uint8_t *header;

	if (zip_source_stat(src, &st) != 0) {
	_zip_error_set_from_source(&ctx->error, src);
	return -1;
	}

	_zip_u2d_time(st.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;
	}

	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:
	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;
	}
	ctx->buffer = NULL;
	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);
	}