10 files changed, 488 insertions, 64 deletions

diff --git a/Android.mk b/Android.mk
index 199aba43b..72fa98c28 100644
--- a/Android.mk
+++ b/Android.mk
@@ -27,6 +27,7 @@ LOCAL_SRC_FILES := \
     verifier.cpp \
     fixPermissions.cpp \
     twrpTar.cpp \
+    twrpDigest.cpp \
     adb_install.cpp
 
 LOCAL_SRC_FILES += \
diff --git a/digest/md5.c b/digest/md5.c
new file mode 100644
index 000000000..488d16ef6
--- /dev/null
+++ b/digest/md5.c
@@ -0,0 +1,257 @@
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+#include <string.h>		/* for memcpy() */
+
+#include "md5.h"
+
+#if !defined(WORDS_BIGENDIAN)
+#define byteReverse(buf, len)	/* Nothing */
+#else
+void byteReverse(unsigned char *buf, unsigned longs);
+
+#ifndef ASM_MD5
+/*
+ * Note: this code is harmless on little-endian machines.
+ */
+void byteReverse(unsigned char *buf, unsigned longs)
+{
+    uint32_t t;
+    do {
+	t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
+	    ((unsigned) buf[1] << 8 | buf[0]);
+	*(uint32_t *) buf = t;
+	buf += 4;
+    } while (--longs);
+}
+#endif
+#endif
+
+/*
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+void MD5Init(struct MD5Context *ctx)
+{
+    ctx->buf[0] = 0x67452301;
+    ctx->buf[1] = 0xefcdab89;
+    ctx->buf[2] = 0x98badcfe;
+    ctx->buf[3] = 0x10325476;
+
+    ctx->bits[0] = 0;
+    ctx->bits[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
+{
+    uint32_t t;
+
+    /* Update bitcount */
+
+    t = ctx->bits[0];
+    if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
+	ctx->bits[1]++;		/* Carry from low to high */
+    ctx->bits[1] += len >> 29;
+
+    t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */
+
+    /* Handle any leading odd-sized chunks */
+
+    if (t) {
+	unsigned char *p = (unsigned char *) ctx->in + t;
+
+	t = 64 - t;
+	if (len < t) {
+	    memcpy(p, buf, len);
+	    return;
+	}
+	memcpy(p, buf, t);
+	byteReverse(ctx->in, 16);
+	MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+	buf += t;
+	len -= t;
+    }
+    /* Process data in 64-byte chunks */
+
+    while (len >= 64) {
+	memcpy(ctx->in, buf, 64);
+	byteReverse(ctx->in, 16);
+	MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+	buf += 64;
+	len -= 64;
+    }
+
+    /* Handle any remaining bytes of data. */
+
+    memcpy(ctx->in, buf, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern 
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+void MD5Final(unsigned char digest[MD5LENGTH], struct MD5Context *ctx)
+{
+    unsigned count;
+    unsigned char *p;
+
+    /* Compute number of bytes mod 64 */
+    count = (ctx->bits[0] >> 3) & 0x3F;
+
+    /* Set the first char of padding to 0x80.  This is safe since there is
+       always at least one byte free */
+    p = ctx->in + count;
+    *p++ = 0x80;
+
+    /* Bytes of padding needed to make 64 bytes */
+    count = 64 - 1 - count;
+
+    /* Pad out to 56 mod 64 */
+    if (count < 8) {
+	/* Two lots of padding:  Pad the first block to 64 bytes */
+	memset(p, 0, count);
+	byteReverse(ctx->in, 16);
+	MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+
+	/* Now fill the next block with 56 bytes */
+	memset(ctx->in, 0, 56);
+    } else {
+	/* Pad block to 56 bytes */
+	memset(p, 0, count - 8);
+    }
+    byteReverse(ctx->in, 14);
+
+    /* Append length in bits and transform.
+     * Use memcpy to avoid aliasing problems.  On most systems,
+     * this will be optimized away to the same code.
+     */
+    memcpy(&ctx->in[14 * sizeof(uint32_t)], &ctx->bits[0], 4);
+    memcpy(&ctx->in[15 * sizeof(uint32_t)], &ctx->bits[1], 4);
+
+    MD5Transform(ctx->buf, (uint32_t *) ctx->in);
+    byteReverse((unsigned char *) ctx->buf, 4);
+    memcpy(digest, ctx->buf, MD5LENGTH);
+    memset(ctx, 0, sizeof(*ctx));	/* In case it's sensitive */
+}
+
+#ifndef ASM_MD5
+
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f, w, x, y, z, data, s) \
+	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+void MD5Transform(uint32_t buf[4], uint32_t const in[16])
+{
+    register uint32_t a, b, c, d;
+
+    a = buf[0];
+    b = buf[1];
+    c = buf[2];
+    d = buf[3];
+
+    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+    buf[0] += a;
+    buf[1] += b;
+    buf[2] += c;
+    buf[3] += d;
+}
+
+#endif
+
diff --git a/digest/md5.h b/digest/md5.h
new file mode 100644
index 000000000..d997e379d
--- /dev/null
+++ b/digest/md5.h
@@ -0,0 +1,29 @@
+#ifndef MD5_H
+#define MD5_H
+
+#ifdef HAVE_STDINT_H
+#include <stdint.h>
+#else
+typedef unsigned int uint32_t;
+#endif
+
+#define MD5LENGTH 16
+
+struct MD5Context {
+	uint32_t buf[4];
+	uint32_t bits[2];
+	unsigned char in[64];
+};
+
+void MD5Init(struct MD5Context *context);
+void MD5Update(struct MD5Context *context, unsigned char const *buf,
+	       unsigned len);
+void MD5Final(unsigned char digest[MD5LENGTH], struct MD5Context *context);
+void MD5Transform(uint32_t buf[4], uint32_t const in[16]);
+
+/*
+ * This is needed to make RSAREF happy on some MS-DOS compilers.
+ */
+typedef struct MD5Context MD5_CTX;
+
+#endif /* !MD5_H */
diff --git a/partition.cpp b/partition.cpp
index e158e0ab8..346c298b2 100644
--- a/partition.cpp
+++ b/partition.cpp
@@ -41,6 +41,7 @@
 #include "partitions.hpp"
 #include "data.hpp"
 #include "twrp-functions.hpp"
+#include "twrpDigest.hpp"
 #include "twrpTar.hpp"
 extern "C" {
 	#include "mtdutils/mtdutils.h"
@@ -943,13 +944,15 @@ bool TWPartition::Check_MD5(string restore_folder) {
 	string Full_Filename;
 	char split_filename[512];
 	int index = 0;
+	twrpDigest md5sum;
 
 	Full_Filename = restore_folder + "/" + Backup_FileName;
 	if (!TWFunc::Path_Exists(Full_Filename)) {
 		// This is a split archive, we presume
 		sprintf(split_filename, "%s%03i", Full_Filename.c_str(), index);
 		while (index < 1000 && TWFunc::Path_Exists(split_filename)) {
-			if (TWFunc::Check_MD5(split_filename) == 0) {
+			md5sum.setfn(split_filename);
+			if (md5sum.verify_md5digest() != 0) {
 				LOGE("MD5 failed to match on '%s'.\n", split_filename);
 				return false;
 			}
@@ -959,7 +962,8 @@ bool TWPartition::Check_MD5(string restore_folder) {
 		return true;
 	} else {
 		// Single file archive
-		if (TWFunc::Check_MD5(Full_Filename) == 0) {
+		md5sum.setfn(Full_Filename);
+		if (md5sum.verify_md5digest() != 0) {
 			LOGE("MD5 failed to match on '%s'.\n", split_filename);
 			return false;
 		} else
@@ -1269,7 +1273,7 @@ bool TWPartition::Backup_Tar(string backup_folder) {
 	unsigned long long total_bsize = 0, file_size;
 	twrpTar tar;
 	vector <string> files;
-	
+
 	if (!Mount(true))
 		return false;
 
diff --git a/partitionmanager.cpp b/partitionmanager.cpp
index 895d3617f..9beb2575f 100644
--- a/partitionmanager.cpp
+++ b/partitionmanager.cpp
@@ -40,6 +40,7 @@
 #include "data.hpp"
 #include "twrp-functions.hpp"
 #include "fixPermissions.hpp"
+#include "twrpDigest.hpp"
 
 #ifdef TW_INCLUDE_CRYPTO
 	#ifdef TW_INCLUDE_JB_CRYPTO
@@ -477,6 +478,7 @@ bool TWPartitionManager::Make_MD5(bool generate_md5, string Backup_Folder, strin
 	string command;
 	string Full_File = Backup_Folder + Backup_Filename;
 	string result;
+	twrpDigest md5sum;
 
 	if (!generate_md5) 
 		return true;
@@ -485,30 +487,39 @@ bool TWPartitionManager::Make_MD5(bool generate_md5, string Backup_Folder, strin
 	ui_print(" * Generating md5...\n");
 
 	if (TWFunc::Path_Exists(Full_File)) {
-		command = "cd '" + Backup_Folder + "' && md5sum '" + Backup_Filename + "' > '" + Backup_Filename + ".md5'";
-		if (TWFunc::Exec_Cmd(command, result) == 0) {
-			ui_print(" * MD5 Created.\n");
-			return true;
-		} else {
+		md5sum.setfn(Backup_Folder + Backup_Filename);
+		if (md5sum.computeMD5() == 0)
+			if (md5sum.write_md5digest() == 0)
+				ui_print(" * MD5 Created.\n");
+			else
+				return -1;
+		else
 			ui_print(" * MD5 Error!\n");
-			return false;
-		}
 	} else {
 		char filename[512];
 		int index = 0;
+		string strfn;
 		sprintf(filename, "%s%03i", Full_File.c_str(), index);
+		strfn = filename;
+		ostringstream intToStr;
+		ostringstream fn;
 		while (TWFunc::Path_Exists(filename) == true) {
-			ostringstream intToStr;
 			intToStr << index;
-			ostringstream fn;
 			fn << setw(3) << setfill('0') << intToStr.str();
-			command = "cd '" + Backup_Folder + "' && md5sum '" + Backup_Filename + fn.str() + "' > '"  + Backup_Filename + fn.str() + ".md5'";
-			if (TWFunc::Exec_Cmd(command, result) != 0) {
-				ui_print(" * MD5 Error.\n");
-				return false;
+			md5sum.setfn(strfn);
+			if (md5sum.computeMD5() == 0) {
+				if (md5sum.write_md5digest() != 0)
+				{
+					ui_print(" * MD5 Error.\n");
+					return false;
+				}
+			}
+			else {
+				return -1;
 			}
 			index++;
 			sprintf(filename, "%s%03i", Full_File.c_str(), index);
+			strfn = filename;
 		}
 		if (index == 0) {
 			LOGE("Backup file: '%s' not found!\n", filename);
diff --git a/twinstall.cpp b/twinstall.cpp
index 40d715564..e1133c01e 100644
--- a/twinstall.cpp
+++ b/twinstall.cpp
@@ -39,6 +39,7 @@
 #include "variables.h"
 #include "data.hpp"
 #include "partitions.hpp"
+#include "twrpDigest.hpp"
 #include "twrp-functions.hpp"
 
 extern RecoveryUI* ui;
@@ -261,7 +262,8 @@ exit:
 
 extern "C" int TWinstall_zip(const char* path, int* wipe_cache) {
 	int err, zip_verify, md5_return;
-
+	twrpDigest md5sum;
+	string strpath = path;
 	ui_print("Installing '%s'...\n", path);
 
 	if (!PartitionManager.Mount_By_Path(path, 0)) {
@@ -270,14 +272,15 @@ extern "C" int TWinstall_zip(const char* path, int* wipe_cache) {
 	}
 
 	ui_print("Checking for MD5 file...\n");
-	md5_return = TWFunc::Check_MD5(path);
-	if (md5_return == 0) {
+	md5sum.setfn(strpath);
+	md5_return = md5sum.verify_md5digest();
+	if (md5_return == -2) {
 		// MD5 did not match.
 		LOGE("Zip MD5 does not match.\nUnable to install zip.\n");
 		return INSTALL_CORRUPT;
 	} else if (md5_return == -1) {
 		ui_print("Skipping MD5 check: no MD5 file found.\n");
-	} else if (md5_return == 1)
+	} else if (md5_return == 0)
 		ui_print("Zip MD5 matched.\n"); // MD5 found and matched.
 
 	DataManager::GetValue(TW_SIGNED_ZIP_VERIFY_VAR, zip_verify);
diff --git a/twrp-functions.cpp b/twrp-functions.cpp
index a90be5a6d..76ee93a1e 100644
--- a/twrp-functions.cpp
+++ b/twrp-functions.cpp
@@ -49,48 +49,6 @@ int TWFunc::Exec_Cmd(string cmd, string &result) {
 	return ret;
 }
 
-/*  Checks md5 for a path
-	Return values:
-		-1 : MD5 does not exist
-		0 : Failed
-		1 : Success */
-int TWFunc::Check_MD5(string File) {
-	int ret;
-	string Command, DirPath, MD5_File, Sline, Filename, MD5_File_Filename, OK;
-	char line[255];
-	size_t pos;
-	string result;
-
-	MD5_File = File + ".md5";
-	if (Path_Exists(MD5_File)) {
-		DirPath = Get_Path(File);
-		MD5_File = Get_Filename(MD5_File);
-		Command = "cd '" + DirPath + "' && /sbin/busybox md5sum -c '" + MD5_File + "'";
-		Exec_Cmd(Command, result);
-		pos = result.find(":");
-		if (pos != string::npos) {
-			Filename = Get_Filename(File);
-			MD5_File_Filename = result.substr(0, pos);
-			OK = result.substr(pos + 2, result.size() - pos - 2);
-			if (Filename == MD5_File_Filename && (OK == "OK" || OK == "OK\n")) {
-				//MD5 is good, return 1
-				ret = 1;
-			} else {
-				// MD5 is bad, return 0
-				ret = 0;
-			}
-		} else {
-			// MD5 is bad, return 0
-			ret = 0;
-		}
-	} else {
-		//No md5 file, return -1
-		ret = -1;
-	}
-
-	return ret;
-}
-
 // Returns "file.name" from a full /path/to/file.name
 string TWFunc::Get_Filename(string Path) {
 	size_t pos = Path.find_last_of("/");
@@ -482,10 +440,24 @@ unsigned int TWFunc::Get_D_Type_From_Stat(string Path) {
 }
 
 int TWFunc::read_file(string fn, string& results) {
+        ifstream file;
+        file.open(fn.c_str(), ios::in);
+        if (file.is_open()) {
+                file >> results;
+                file.close();
+                return 0;
+	}
+        LOGI("Cannot find file %s\n", fn.c_str());
+        return -1;
+}
+
+int TWFunc::read_file(string fn, vector<string>& results) {
 	ifstream file;
+	string line;
 	file.open(fn.c_str(), ios::in);
 	if (file.is_open()) {
-		file >> results;
+		while (getline(file, line))
+			results.push_back(line);
 		file.close();
 		return 0;
 	}
diff --git a/twrp-functions.hpp b/twrp-functions.hpp
index 421962281..042c56722 100644
--- a/twrp-functions.hpp
+++ b/twrp-functions.hpp
@@ -19,7 +19,6 @@ typedef enum
 class TWFunc
 {
 public:
-	static int Check_MD5(string File);
 	static string Get_Root_Path(string Path);                                   // Trims any trailing folders or filenames from the path, also adds a leading / if not present
 	static string Get_Path(string Path);                                        // Trims everything after the last / in the string
 	static string Get_Filename(string Path);                                    // Trims the path off of a filename
@@ -41,6 +40,7 @@ public:
 	static int copy_file(string src, string dst, int mode); //copy file from src to dst with mode permissions
 	static unsigned int Get_D_Type_From_Stat(string Path);                      // Returns a dirent dt_type value using stat instead of dirent
 	static timespec timespec_diff(timespec& start, timespec& end);	            // Return a diff for 2 times
+	static int read_file(string fn, vector<string>& results); //read from file
 	static int read_file(string fn, string& results); //read from file
 	static int write_file(string fn, string& line); //write from file
 	static int drop_caches(void); //drop linux cache memory
diff --git a/twrpDigest.cpp b/twrpDigest.cpp
new file mode 100644
index 000000000..16cda3d68
--- /dev/null
+++ b/twrpDigest.cpp
@@ -0,0 +1,112 @@
+/*
+	Copyright 2012 bigbiff/Dees_Troy TeamWin
+	This file is part of TWRP/TeamWin Recovery Project.
+
+	TWRP is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	TWRP is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with TWRP.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+extern "C" {
+	#include "digest/md5.h"
+	#include "libcrecovery/common.h"
+}
+#include <vector>
+#include <string>
+#include <sstream>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <string.h>
+#include <libgen.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <sstream>
+#include <dirent.h>
+#include <sys/mman.h>
+#include "common.h"
+#include "data.hpp"
+#include "variables.h"
+#include "twrp-functions.hpp"
+#include "twrpDigest.hpp"
+
+using namespace std;
+
+void twrpDigest::setfn(string fn) {
+	md5fn = fn;
+}
+
+int twrpDigest::computeMD5(void) {
+	string line;
+	struct MD5Context md5c;
+	FILE *file;
+	int len;
+	unsigned char buf[1024];
+	MD5Init(&md5c);
+	file = fopen(md5fn.c_str(), "rb");
+	if (file == NULL)
+		return -1;
+	while ((len = fread(buf, 1, sizeof(buf), file)) > 0) {
+		MD5Update(&md5c, buf, len);
+	}
+	MD5Final(md5sum ,&md5c);
+	return 0;
+}
+
+int twrpDigest::write_md5digest(void) {
+	int i;
+	string md5string, md5file;
+	char hex[3];
+	md5file = md5fn + ".md5";
+
+	for (i = 0; i < 16; ++i) {
+		snprintf(hex, 3 ,"%02x", md5sum[i]);
+		md5string += hex;
+	}
+	md5string += "  ";
+	md5string += basename((char*) md5fn.c_str());
+	md5string +=  + "\n";
+	TWFunc::write_file(md5file, md5string);
+	return 0;
+}
+
+int twrpDigest::read_md5digest(void) {
+	string md5file = md5fn + ".md5";
+	if (TWFunc::read_file(md5file, lines) != 0)
+		return -1;
+	return 0;
+}
+
+int twrpDigest::verify_md5digest(void) {
+	string buf;
+	char hex[3];
+	int i;
+	string md5string;
+
+	if (read_md5digest() != 0)
+		return -1;
+	stringstream ss(lines.at(0));
+	vector<string> tokens;
+	while (ss >> buf)
+		tokens.push_back(buf);
+	computeMD5();
+	for (i = 0; i < 16; ++i) {
+		snprintf(hex, 3, "%02x", md5sum[i]);
+		md5string += hex;
+	}
+	if (tokens.at(0) != md5string)
+		return -2;
+	return 0;
+}
diff --git a/twrpDigest.hpp b/twrpDigest.hpp
new file mode 100644
index 000000000..80828fca5
--- /dev/null
+++ b/twrpDigest.hpp
@@ -0,0 +1,35 @@
+/*
+        Copyright 2012 bigbiff/Dees_Troy TeamWin
+        This file is part of TWRP/TeamWin Recovery Project.
+
+        TWRP is free software: you can redistribute it and/or modify
+        it under the terms of the GNU General Public License as published by
+        the Free Software Foundation, either version 3 of the License, or
+        (at your option) any later version.
+
+        TWRP is distributed in the hope that it will be useful,
+        but WITHOUT ANY WARRANTY; without even the implied warranty of
+        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+        GNU General Public License for more details.
+
+        You should have received a copy of the GNU General Public License
+        along with TWRP.  If not, see <http://www.gnu.org/licenses/>.
+*/
+extern "C" {
+	#include "digest/md5.h"
+}
+using namespace std;
+
+class twrpDigest {
+	public:
+                void setfn(string fn);
+                void setdir(string dir);
+		int computeMD5(void);
+		int verify_md5digest(void);
+		int write_md5digest(void);
+	private:
+		int read_md5digest(void);
+		string md5fn;
+		vector<string> lines;
+		unsigned char md5sum[MD5LENGTH];
+};