Initial commit

1 files changed, 200 insertions, 0 deletions

diff --git a/unzip.c b/unzip.c
new file mode 100644
index 0000000..1345ddb
--- /dev/null
+++ b/unzip.c
@@ -0,0 +1,200 @@
+#include <stdlib.h>
+#include <string.h>
+#include "main.h"
+#include "unzip.h"
+#include "zlib.h"
+
+#define HEADER_SIZE 30
+#define CHUNK 65536
+
+#define LE_READ16(buf) ((uint16_t)(((uint8_t *)(buf))[1] << 8 | ((uint8_t *)(buf))[0]))
+#define LE_READ32(buf) ((uint32_t)(((uint8_t *)(buf))[3] << 24 | ((uint8_t *)(buf))[2] << 16 | ((uint8_t *)(buf))[1] << 8 | ((uint8_t *)(buf))[0]))
+
+struct file_info {
+	uint32_t compressed_size;
+	int (*inflate)(FILE *zip, FILE *dest, size_t size);
+	char filename[MAX_PATH];
+};
+
+static int write_uncompressed(FILE *zip, FILE *dest, size_t size) {
+	uint8_t buf[CHUNK];
+
+	while (size) {
+		size_t wsize = MIN(size, CHUNK);
+
+		if (size != fread(buf, 1, wsize, zip)) {
+			return -1;
+		}
+		if (size != fwrite(buf, 1, wsize, zip)) {
+			return -1;
+		}
+		size -= wsize;
+	}
+	return 0;
+}
+
+static int write_inflate(FILE *zip, FILE *dest, size_t size) {
+	z_stream stream = {0};
+	size_t have = 0;
+	uint8_t in[CHUNK];
+	uint8_t out[CHUNK];
+	int ret = -1;
+
+	ret = inflateInit2(&stream, -MAX_WBITS);
+	if (ret != Z_OK)
+		return ret;
+
+	do {
+		size_t insize = MIN(size, CHUNK);
+
+		stream.avail_in = fread(in, 1, insize, zip);
+		if (ferror(zip)) {
+			(void)inflateEnd(&stream);
+			return Z_ERRNO;
+		}
+
+		if (!stream.avail_in)
+			break;
+		stream.next_in = in;
+
+		do {
+			stream.avail_out = CHUNK;
+			stream.next_out = out;
+
+			ret = inflate(&stream, Z_NO_FLUSH);
+			switch(ret) {
+			case Z_NEED_DICT:
+				ret = Z_DATA_ERROR;
+			case Z_DATA_ERROR:
+			case Z_MEM_ERROR:
+				(void)inflateEnd(&stream);
+				return ret;
+			}
+
+			have = CHUNK - stream.avail_out;
+			if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
+				(void)inflateEnd(&stream);
+				return Z_ERRNO;
+			}
+		} while (stream.avail_out == 0);
+
+		size -= insize;
+	} while (size && ret != Z_STREAM_END);
+
+	(void)inflateEnd(&stream);
+
+	if (!size || ret == Z_STREAM_END) {
+		return Z_OK;
+	} else {
+		return Z_DATA_ERROR;
+	}
+}
+
+static int find_entry(FILE *zip, const char **extensions, struct file_info *info) {
+	int ret = -1;
+	uint8_t header[HEADER_SIZE];
+	uint32_t next = 0;
+	uint16_t file_name_size = 0;
+	char extension[10];
+
+	while(1) {
+		bool match = false;
+
+		if (next)
+			fseek(zip, next, SEEK_CUR);
+
+		if (HEADER_SIZE != fread(header, 1, HEADER_SIZE, zip))
+			break;
+
+		if (header[0] != 0x50 || header[1] != 0x4b || header[2] != 0x03 || header[3] != 0x04)
+			break;
+
+		if ((uint16_t)(header[6]) & 0x0008) {
+			PA_ERROR("Unsupported zip file\n");
+			break;
+		}
+
+		file_name_size = LE_READ16(&header[26]);
+		if (file_name_size >= MAX_PATH)
+			break;
+
+		if (file_name_size != fread(info->filename, 1, file_name_size, zip))
+			break;
+
+		info->filename[file_name_size] = '\0';
+		info->compressed_size = LE_READ32(&header[18]);
+
+		fseek(zip, LE_READ16(&header[28]), SEEK_CUR);
+
+		next = info->compressed_size;
+
+		for (int i = 0; extensions[i]; i++) {
+			snprintf(extension, 10, ".%s", extensions[i]);
+			if (has_suffix_i(info->filename, extension)) {
+				match = true;
+				break;
+			}
+		}
+
+		if (!match)
+			continue;
+
+		switch (LE_READ16(&header[8])) {
+		case 0: /* Uncompressed */
+			info->inflate = write_uncompressed;
+		case 8: /* DEFLATE */
+			info->inflate = write_inflate;
+		}
+
+		ret = 0;
+		break;
+	}
+	return ret;
+}
+
+int unzip_tmp(FILE *zip, const char **extensions, char *filename, size_t len) {
+	int ret = -1;
+	struct file_info info = {0};
+	FILE *dest = NULL;
+
+	if (!find_entry(zip, extensions, &info)) {
+		int fd = 0;
+		snprintf(filename, len, "/tmp/pa-XXXXXX%s", basename(info.filename));
+
+		fd = mkstemps(filename, strlen(info.filename));
+		dest = fdopen(fd, "w");
+
+		if (!dest) {
+			PA_ERROR("Error creating temporary file for decompression\n");
+			goto finish;
+		}
+
+		if (info.inflate(zip, dest, info.compressed_size)) {
+			PA_ERROR("Error decompressing file\n");
+			goto finish;
+		}
+
+		ret = 0;
+	}
+
+finish:
+	if (dest)
+		fclose(dest);
+	return ret;
+}
+
+int unzip(FILE *zip, const char **extensions, FILE *dest) {
+	int ret = -1;
+	struct file_info info = {0};
+
+	if(!find_entry(zip, extensions, &info)) {
+		if (!info.inflate(zip, dest, info.compressed_size)) {
+			ret = 0;
+		} else {
+			PA_ERROR("Error decompressing file\n");
+		}
+
+	}
+
+	return ret;
+}