Winzip AES encryption support for writing.
diff --git a/lib/zip_source_winzip_aes_decode.c b/lib/zip_source_winzip_aes_decode.c
new file mode 100644
index 0000000..e083f95
--- /dev/null
+++ b/lib/zip_source_winzip_aes_decode.c
@@ -0,0 +1,282 @@
+/*
+ zip_source_winzip_aes.c -- Winzip AES de/encryption routines
+ Copyright (C) 2009-2015 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"
+
+#include "gladman-fcrypt.h"
+
+#define MAX_HEADER_LENGTH (16+PWD_VER_LENGTH)
+#define HMAC_LENGTH 10
+
+static int salt_length[] = { 0, 8, 12, 16 };
+
+struct winzip_aes {
+ char *password;
+ int mode;
+
+ zip_uint64_t data_length;
+ zip_uint64_t current_position;
+
+ fcrypt_ctx fcrypt_ctx;
+ zip_error_t error;
+};
+
+
+static int decrypt_header(zip_source_t *src, struct winzip_aes *ctx);
+static void winzip_aes_free(struct winzip_aes *);
+static zip_int64_t winzip_aes_decrypt(zip_source_t *src, void *ud, void *data, zip_uint64_t len, zip_source_cmd_t cmd);
+static struct winzip_aes * winzip_aes_new(int mode, const char *password);
+
+
+zip_source_t *
+zip_source_winzip_aes_decode(zip_t *za, zip_source_t *src, zip_uint16_t em, int flags, const char *password)
+{
+ zip_source_t *s2;
+ int mode = 0;
+ zip_stat_t st;
+ zip_uint64_t aux_length;
+ struct winzip_aes *ctx;
+
+ switch (em) {
+ case ZIP_EM_AES_128:
+ mode = 1;
+ break;
+ case ZIP_EM_AES_192:
+ mode = 2;
+ break;
+ case ZIP_EM_AES_256:
+ mode = 3;
+ break;
+ }
+
+ if (password == NULL || src == NULL || mode == 0) {
+ 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 (zip_source_stat(src, &st) != 0) {
+ _zip_error_set_from_source(&za->error, src);
+ return NULL;
+ }
+
+ aux_length = PWD_VER_LENGTH + salt_length[mode] + HMAC_LENGTH;
+
+ if ((st.valid & ZIP_STAT_COMP_SIZE) == 0 || st.comp_size < aux_length) {
+ zip_error_set(&za->error, ZIP_ER_OPNOTSUPP, 0);
+ return NULL;
+ }
+
+ if ((ctx = winzip_aes_new(mode, password)) == NULL) {
+ zip_error_set(&za->error, ZIP_ER_MEMORY, 0);
+ return NULL;
+ }
+
+ ctx->data_length = st.comp_size - aux_length;
+
+ if ((s2 = zip_source_layered(za, src, winzip_aes_decrypt, ctx)) == NULL) {
+ winzip_aes_free(ctx);
+ return NULL;
+ }
+
+ return s2;
+}
+
+
+static int
+decrypt_header(zip_source_t *src, struct winzip_aes *ctx)
+{
+ zip_uint8_t header[MAX_HEADER_LENGTH];
+ zip_uint8_t password_verification[PWD_VER_LENGTH];
+ zip_uint8_t headerlen;
+ zip_int64_t n;
+ unsigned char key[16];
+
+ headerlen = PWD_VER_LENGTH + salt_length[ctx->mode];
+ if ((n=zip_source_read(src, header, headerlen)) < 0) {
+ _zip_error_set_from_source(&ctx->error, src);
+ return -1;
+ }
+
+ if (n != headerlen) {
+ zip_error_set(&ctx->error, ZIP_ER_EOF, 0);
+ return -1;
+ }
+
+ if (_zip_fcrypt_init(ctx->mode, ctx->password, strlen(ctx->password), header, password_verification, &ctx->fcrypt_ctx) != 0) {
+ zip_error_set(&ctx->error, ZIP_ER_MEMORY, 0);
+ return -1;
+ }
+ if (memcmp(password_verification, header + salt_length[ctx->mode], PWD_VER_LENGTH) != 0) {
+ zip_error_set(&ctx->error, ZIP_ER_WRONGPASSWD, 0);
+ return -1;
+ }
+ return 0;
+}
+
+
+static bool
+verify_hmac(zip_source_t *src, struct winzip_aes *ctx)
+{
+ unsigned char computed[HMAC_LENGTH], from_file[HMAC_LENGTH];
+ if (zip_source_read(src, from_file, HMAC_LENGTH) < HMAC_LENGTH) {
+ _zip_error_set_from_source(&ctx->error, src);
+ return false;
+ }
+
+ _zip_fcrypt_end(computed, &ctx->fcrypt_ctx);
+
+ if (memcmp(from_file, computed, HMAC_LENGTH) != 0) {
+ zip_error_set(&ctx->error, ZIP_ER_CRC, 0);
+ return false;
+ }
+
+ return true;
+}
+
+
+static zip_int64_t
+winzip_aes_decrypt(zip_source_t *src, void *ud, void *data, zip_uint64_t len, zip_source_cmd_t cmd)
+{
+ struct winzip_aes *ctx;
+ zip_int64_t n;
+
+ ctx = (struct winzip_aes *)ud;
+
+ switch (cmd) {
+ case ZIP_SOURCE_OPEN:
+ if (decrypt_header(src, ctx) < 0) {
+ return -1;
+ }
+ ctx->current_position = 0;
+ return 0;
+
+ case ZIP_SOURCE_READ:
+ if (len > ctx->data_length - ctx->current_position) {
+ len = ctx->data_length - ctx->current_position;
+ }
+
+ if (len == 0) {
+ if (!verify_hmac(src, ctx)) {
+ return -1;
+ }
+ return 0;
+ }
+
+ if ((n=zip_source_read(src, data, len)) < 0) {
+ _zip_error_set_from_source(&ctx->error, src);
+ return -1;
+ }
+ ctx->current_position += n;
+
+ /* TODO: loop if len > UINT_MAX */
+ _zip_fcrypt_decrypt(data, n, &ctx->fcrypt_ctx);
+
+ 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 -= 12 + salt_length[ctx->mode];
+ }
+
+ 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:
+ winzip_aes_free(ctx);
+ return 0;
+
+ default:
+ zip_error_set(&ctx->error, ZIP_ER_INVAL, 0);
+ return -1;
+ }
+}
+
+
+static void
+winzip_aes_free(struct winzip_aes *ctx)
+{
+ if (ctx == NULL) {
+ return;
+ }
+
+ _zip_crypto_clear(&ctx->fcrypt_ctx, sizeof(ctx->fcrypt_ctx));
+ _zip_crypto_clear(ctx->password, strlen(ctx->password));
+ free(ctx->password);
+ zip_error_fini(&ctx->error);
+ free(ctx);
+}
+
+
+static struct winzip_aes *
+winzip_aes_new(int mode, const char *password) {
+ struct winzip_aes *ctx;
+
+ if ((ctx = (struct winzip_aes *)malloc(sizeof(*ctx))) == NULL) {
+ return NULL;
+ }
+
+ if ((ctx->password = strdup(password)) == NULL) {
+ free(ctx);
+ return NULL;
+ }
+
+ ctx->mode = mode;
+
+ zip_error_init(&ctx->error);
+
+ return ctx;
+}
