1 files changed, 191 insertions, 0 deletions
diff --git a/tools/src/tinf/tinfgzip.c b/tools/src/tinf/tinfgzip.c
new file mode 100644
index 0000000..ea07cd7
--- /dev/null
+++ b/tools/src/tinf/tinfgzip.c
@@ -0,0 +1,191 @@
+/*
+ * tinfgzip - tiny gzip decompressor
+ *
+ * Copyright (c) 2003-2019 Joergen Ibsen
+ *
+ * This version of tinfzlib was modified for use with m1n1.
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ *   1. The origin of this software must not be misrepresented; you must
+ *      not claim that you wrote the original software. If you use this
+ *      software in a product, an acknowledgment in the product
+ *      documentation would be appreciated but is not required.
+ *
+ *   2. Altered source versions must be plainly marked as such, and must
+ *      not be misrepresented as being the original software.
+ *
+ *   3. This notice may not be removed or altered from any source
+ *      distribution.
+ */
+
+#include "tinf.h"
+
+typedef enum {
+	FTEXT    = 1,
+	FHCRC    = 2,
+	FEXTRA   = 4,
+	FNAME    = 8,
+	FCOMMENT = 16
+} tinf_gzip_flag;
+
+static unsigned int read_le16(const unsigned char *p)
+{
+	return ((unsigned int) p[0])
+	     | ((unsigned int) p[1] << 8);
+}
+
+static unsigned int read_le32(const unsigned char *p)
+{
+	return ((unsigned int) p[0])
+	     | ((unsigned int) p[1] << 8)
+	     | ((unsigned int) p[2] << 16)
+	     | ((unsigned int) p[3] << 24);
+}
+
+int tinf_gzip_uncompress(void *dest, unsigned int *destLen,
+                         const void *source, unsigned int *sourceLen)
+{
+	const unsigned char *src = (const unsigned char *) source;
+	unsigned char *dst = (unsigned char *) dest;
+	const unsigned char *start;
+	unsigned int dlen, crc32;
+	int res;
+	unsigned char flg;
+	unsigned int sourceDataLen = 0;
+
+	/* -- Check header -- */
+
+	/* Check room for at least 10 byte header and 8 byte trailer */
+	if (*sourceLen && *sourceLen < 18) {
+		return TINF_DATA_ERROR;
+	}
+
+	/* Check id bytes */
+	if (src[0] != 0x1F || src[1] != 0x8B) {
+		return TINF_DATA_ERROR;
+	}
+
+	/* Check method is deflate */
+	if (src[2] != 8) {
+		return TINF_DATA_ERROR;
+	}
+
+	/* Get flag byte */
+	flg = src[3];
+
+	/* Check that reserved bits are zero */
+	if (flg & 0xE0) {
+		return TINF_DATA_ERROR;
+	}
+
+	/* -- Find start of compressed data -- */
+
+	/* Skip base header of 10 bytes */
+	start = src + 10;
+
+	/* Skip extra data if present */
+	if (flg & FEXTRA) {
+		unsigned int xlen = read_le16(start);
+
+		if (*sourceLen && xlen > *sourceLen - 12) {
+			return TINF_DATA_ERROR;
+		}
+
+		start += xlen + 2;
+	}
+
+	/* Skip file name if present */
+	if (flg & FNAME) {
+		do {
+			if (*sourceLen && start - src >= *sourceLen) {
+				return TINF_DATA_ERROR;
+			}
+		} while (*start++);
+	}
+
+	/* Skip file comment if present */
+	if (flg & FCOMMENT) {
+		do {
+			if (*sourceLen && start - src >= *sourceLen) {
+				return TINF_DATA_ERROR;
+			}
+		} while (*start++);
+	}
+
+	/* Check header crc if present */
+	if (flg & FHCRC) {
+		unsigned int hcrc;
+
+		if (*sourceLen && start - src > *sourceLen - 2) {
+			return TINF_DATA_ERROR;
+		}
+
+		hcrc = read_le16(start);
+
+		if (hcrc != (tinf_crc32(src, start - src) & 0x0000FFFF)) {
+			return TINF_DATA_ERROR;
+		}
+
+		start += 2;
+	}
+
+	/* -- Get decompressed length if available -- */
+
+	if (*sourceLen) {
+		dlen = read_le32(&src[*sourceLen - 4]);
+
+		if (dlen > *destLen) {
+			return TINF_BUF_ERROR;
+		}
+	}
+
+	/* -- Check source length if available -- */
+
+	if (*sourceLen) {
+		if ((src + *sourceLen) - start < 8) {
+			return TINF_DATA_ERROR;
+		}
+		sourceDataLen = (src + *sourceLen) - start - 8;
+	}
+
+	/* -- Decompress data -- */
+
+	res = tinf_uncompress(dst, destLen, start, &sourceDataLen);
+
+	if (res != TINF_OK) {
+		return TINF_DATA_ERROR;
+	}
+
+	sourceDataLen += (start - src) + 8;
+
+	if (*sourceLen && *sourceLen != sourceDataLen) {
+		return TINF_DATA_ERROR;
+	}
+
+	*sourceLen = sourceDataLen;
+
+	/* -- Check decompressed length -- */
+
+	dlen = read_le32(&src[*sourceLen - 4]);
+
+	if (*destLen != dlen) {
+		return TINF_DATA_ERROR;
+	}
+
+	/* -- Check CRC32 checksum -- */
+
+	crc32 = read_le32(&src[*sourceLen - 8]);
+
+	if (crc32 != tinf_crc32(dst, dlen)) {
+		return TINF_DATA_ERROR;
+	}
+
+	return TINF_OK;
+}