Implement Merkle hash verification
diff --git a/js/encoding/ASN1/asn1.js b/js/encoding/ASN1/asn1.js
new file mode 100644
index 0000000..069e02b
--- /dev/null
+++ b/js/encoding/ASN1/asn1.js
@@ -0,0 +1,498 @@
+// ASN.1 JavaScript decoder
+// Copyright (c) 2008-2009 Lapo Luchini <lapo@lapo.it>
+
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+function Stream(enc, pos) {
+    if (enc instanceof Stream) {
+        this.enc = enc.enc;
+        this.pos = enc.pos;
+    } else {
+        this.enc = enc;
+        this.pos = pos;
+    }
+}
+Stream.prototype.get = function(pos) {
+    if (pos == undefined)
+        pos = this.pos++;
+    if (pos >= this.enc.length)
+        throw 'Requesting byte offset ' + pos + ' on a stream of length ' + this.enc.length;
+    return this.enc[pos];
+}
+Stream.prototype.hexDigits = "0123456789ABCDEF";
+Stream.prototype.hexByte = function(b) {
+    return this.hexDigits.charAt((b >> 4) & 0xF) + this.hexDigits.charAt(b & 0xF);
+}
+Stream.prototype.hexDump = function(start, end) {
+    var s = "";
+    for (var i = start; i < end; ++i) {
+        s += this.hexByte(this.get(i));
+        switch (i & 0xF) {
+        case 0x7: s += "  "; break;
+        case 0xF: s += "\n"; break;
+        default:  s += " ";
+        }
+    }
+    return s;
+}
+Stream.prototype.parseStringISO = function(start, end) {
+    var s = "";
+    for (var i = start; i < end; ++i)
+        s += String.fromCharCode(this.get(i));
+    return s;
+}
+Stream.prototype.parseStringUTF = function(start, end) {
+    var s = "", c = 0;
+    for (var i = start; i < end; ) {
+        var c = this.get(i++);
+        if (c < 128)
+            s += String.fromCharCode(c);
+        else if ((c > 191) && (c < 224))
+            s += String.fromCharCode(((c & 0x1F) << 6) | (this.get(i++) & 0x3F));
+        else
+            s += String.fromCharCode(((c & 0x0F) << 12) | ((this.get(i++) & 0x3F) << 6) | (this.get(i++) & 0x3F));
+        //TODO: this doesn't check properly 'end', some char could begin before and end after
+    }
+    return s;
+}
+Stream.prototype.reTime = /^((?:1[89]|2\d)?\d\d)(0[1-9]|1[0-2])(0[1-9]|[12]\d|3[01])([01]\d|2[0-3])(?:([0-5]\d)(?:([0-5]\d)(?:[.,](\d{1,3}))?)?)?(Z|[-+](?:[0]\d|1[0-2])([0-5]\d)?)?$/;
+Stream.prototype.parseTime = function(start, end) {
+    var s = this.parseStringISO(start, end);
+    var m = this.reTime.exec(s);
+    if (!m)
+        return "Unrecognized time: " + s;
+    s = m[1] + "-" + m[2] + "-" + m[3] + " " + m[4];
+    if (m[5]) {
+        s += ":" + m[5];
+        if (m[6]) {
+            s += ":" + m[6];
+            if (m[7])
+                s += "." + m[7];
+        }
+    }
+    if (m[8]) {
+        s += " UTC";
+        if (m[8] != 'Z') {
+            s += m[8];
+            if (m[9])
+                s += ":" + m[9];
+        }
+    }
+    return s;
+}
+Stream.prototype.parseInteger = function(start, end) {
+    //TODO support negative numbers
+    var len = end - start;
+    if (len > 4) {
+        len <<= 3;
+        var s = this.get(start);
+        if (s == 0)
+            len -= 8;
+        else
+            while (s < 128) {
+                s <<= 1;
+                --len;
+            }
+        return "(" + len + " bit)";
+    }
+    var n = 0;
+    for (var i = start; i < end; ++i)
+        n = (n << 8) | this.get(i);
+    return n;
+}
+Stream.prototype.parseBitString = function(start, end) {
+    var unusedBit = this.get(start);
+    var lenBit = ((end - start - 1) << 3) - unusedBit;
+    var s  = "(" + lenBit + " bit)";
+    if (lenBit <= 20) {
+        var skip = unusedBit;
+        s += " ";
+        for (var i = end - 1; i > start; --i) {
+            var b = this.get(i);
+            for (var j = skip; j < 8; ++j)
+                s += (b >> j) & 1 ? "1" : "0";
+            skip = 0;
+        }
+    }
+    return s;
+}
+Stream.prototype.parseOctetString = function(start, end) {
+    var len = end - start;
+    var s = "(" + len + " byte) ";
+    if (len > 20)
+        end = start + 20;
+    for (var i = start; i < end; ++i)
+        s += this.hexByte(this.get(i));
+    if (len > 20)
+        s += String.fromCharCode(8230); // ellipsis
+    return s;
+}
+Stream.prototype.parseOID = function(start, end) {
+    var s, n = 0, bits = 0;
+    for (var i = start; i < end; ++i) {
+        var v = this.get(i);
+        n = (n << 7) | (v & 0x7F);
+        bits += 7;
+        if (!(v & 0x80)) { // finished
+            if (s == undefined)
+                s = parseInt(n / 40) + "." + (n % 40);
+            else
+                s += "." + ((bits >= 31) ? "bigint" : n);
+            n = bits = 0;
+        }
+        s += String.fromCharCode();
+    }
+    return s;
+}
+
+function ASN1(stream, header, length, tag, sub) {
+    this.stream = stream;
+    this.header = header;
+    this.length = length;
+    this.tag = tag;
+    this.sub = sub;
+}
+ASN1.prototype.typeName = function() {
+    if (this.tag == undefined)
+        return "unknown";
+    var tagClass = this.tag >> 6;
+    var tagConstructed = (this.tag >> 5) & 1;
+    var tagNumber = this.tag & 0x1F;
+    switch (tagClass) {
+    case 0: // universal
+        switch (tagNumber) {
+        case 0x00: return "EOC";
+        case 0x01: return "BOOLEAN";
+        case 0x02: return "INTEGER";
+        case 0x03: return "BIT_STRING";
+        case 0x04: return "OCTET_STRING";
+        case 0x05: return "NULL";
+        case 0x06: return "OBJECT_IDENTIFIER";
+        case 0x07: return "ObjectDescriptor";
+        case 0x08: return "EXTERNAL";
+        case 0x09: return "REAL";
+        case 0x0A: return "ENUMERATED";
+        case 0x0B: return "EMBEDDED_PDV";
+        case 0x0C: return "UTF8String";
+        case 0x10: return "SEQUENCE";
+        case 0x11: return "SET";
+        case 0x12: return "NumericString";
+        case 0x13: return "PrintableString"; // ASCII subset
+        case 0x14: return "TeletexString"; // aka T61String
+        case 0x15: return "VideotexString";
+        case 0x16: return "IA5String"; // ASCII
+        case 0x17: return "UTCTime";
+        case 0x18: return "GeneralizedTime";
+        case 0x19: return "GraphicString";
+        case 0x1A: return "VisibleString"; // ASCII subset
+        case 0x1B: return "GeneralString";
+        case 0x1C: return "UniversalString";
+        case 0x1E: return "BMPString";
+        default: return "Universal_" + tagNumber.toString(16);
+        }
+    case 1: return "Application_" + tagNumber.toString(16);
+    case 2: return "[" + tagNumber + "]"; // Context
+    case 3: return "Private_" + tagNumber.toString(16);
+    }
+}
+ASN1.prototype.content = function() {
+    if (this.tag == undefined)
+        return null;
+    var tagClass = this.tag >> 6;
+    if (tagClass != 0) // universal
+        return (this.sub == null) ? null : "(" + this.sub.length + ")";
+    var tagNumber = this.tag & 0x1F;
+    var content = this.posContent();
+    var len = Math.abs(this.length);
+    switch (tagNumber) {
+    case 0x01: // BOOLEAN
+        return (this.stream.get(content) == 0) ? "false" : "true";
+    case 0x02: // INTEGER
+        return this.stream.parseInteger(content, content + len);
+    case 0x03: // BIT_STRING
+        return this.sub ? "(" + this.sub.length + " elem)" :
+            this.stream.parseBitString(content, content + len)
+    case 0x04: // OCTET_STRING
+        return this.sub ? "(" + this.sub.length + " elem)" :
+            this.stream.parseOctetString(content, content + len)
+    //case 0x05: // NULL
+    case 0x06: // OBJECT_IDENTIFIER
+        return this.stream.parseOID(content, content + len);
+    //case 0x07: // ObjectDescriptor
+    //case 0x08: // EXTERNAL
+    //case 0x09: // REAL
+    //case 0x0A: // ENUMERATED
+    //case 0x0B: // EMBEDDED_PDV
+    case 0x10: // SEQUENCE
+    case 0x11: // SET
+        return "(" + this.sub.length + " elem)";
+    case 0x0C: // UTF8String
+        return this.stream.parseStringUTF(content, content + len);
+    case 0x12: // NumericString
+    case 0x13: // PrintableString
+    case 0x14: // TeletexString
+    case 0x15: // VideotexString
+    case 0x16: // IA5String
+    //case 0x19: // GraphicString
+    case 0x1A: // VisibleString
+    //case 0x1B: // GeneralString
+    //case 0x1C: // UniversalString
+    //case 0x1E: // BMPString
+        return this.stream.parseStringISO(content, content + len);
+    case 0x17: // UTCTime
+    case 0x18: // GeneralizedTime
+        return this.stream.parseTime(content, content + len);
+    }
+    return null;
+}
+ASN1.prototype.toString = function() {
+    return this.typeName() + "@" + this.stream.pos + "[header:" + this.header + ",length:" + this.length + ",sub:" + ((this.sub == null) ? 'null' : this.sub.length) + "]";
+}
+ASN1.prototype.print = function(indent) {
+    if (indent == undefined) indent = '';
+    document.writeln(indent + this);
+    if (this.sub != null) {
+        indent += '  ';
+        for (var i = 0, max = this.sub.length; i < max; ++i)
+            this.sub[i].print(indent);
+    }
+}
+ASN1.prototype.toPrettyString = function(indent) {
+    if (indent == undefined) indent = '';
+    var s = indent + this.typeName() + " @" + this.stream.pos;
+    if (this.length >= 0)
+        s += "+";
+    s += this.length;
+    if (this.tag & 0x20)
+        s += " (constructed)";
+    else if (((this.tag == 0x03) || (this.tag == 0x04)) && (this.sub != null))
+        s += " (encapsulates)";
+    s += "\n";
+    if (this.sub != null) {
+        indent += '  ';
+        for (var i = 0, max = this.sub.length; i < max; ++i)
+            s += this.sub[i].toPrettyString(indent);
+    }
+    return s;
+}
+ASN1.prototype.toDOM = function() {
+    var node = document.createElement("div");
+    node.className = "node";
+    node.asn1 = this;
+    var head = document.createElement("div");
+    head.className = "head";
+    var s = this.typeName().replace(/_/g, " ");
+    head.innerHTML = s;
+    var content = this.content();
+    if (content != null) {
+        content = String(content).replace(/</g, "&lt;");
+        var preview = document.createElement("span");
+        preview.className = "preview";
+        preview.innerHTML = content;
+        head.appendChild(preview);
+    }
+    node.appendChild(head);
+    this.node = node;
+    this.head = head;
+    var value = document.createElement("div");
+    value.className = "value";
+    s = "Offset: " + this.stream.pos + "<br/>";
+    s += "Length: " + this.header + "+";
+    if (this.length >= 0)
+        s += this.length;
+    else
+        s += (-this.length) + " (undefined)";
+    if (this.tag & 0x20)
+        s += "<br/>(constructed)";
+    else if (((this.tag == 0x03) || (this.tag == 0x04)) && (this.sub != null))
+        s += "<br/>(encapsulates)";
+    //TODO if (this.tag == 0x03) s += "Unused bits: "
+    if (content != null) {
+        s += "<br/>Value:<br/><b>" + content + "</b>";
+        if ((typeof(oids) == 'object') && (this.tag == 0x06)) {
+            var oid = oids[content];
+            if (oid) {
+                if (oid.d) s += "<br/>" + oid.d;
+                if (oid.c) s += "<br/>" + oid.c;
+                if (oid.w) s += "<br/>(warning!)";
+            }
+        }
+    }
+    value.innerHTML = s;
+    node.appendChild(value);
+    var sub = document.createElement("div");
+    sub.className = "sub";
+    if (this.sub != null) {
+        for (var i = 0, max = this.sub.length; i < max; ++i)
+            sub.appendChild(this.sub[i].toDOM());
+    }
+    node.appendChild(sub);
+    head.switchNode = node;
+    head.onclick = function() {
+        var node = this.switchNode;
+        node.className = (node.className == "node collapsed") ? "node" : "node collapsed";
+    };
+    return node;
+}
+ASN1.prototype.posStart = function() {
+    return this.stream.pos;
+}
+ASN1.prototype.posContent = function() {
+    return this.stream.pos + this.header;
+}
+ASN1.prototype.posEnd = function() {
+    return this.stream.pos + this.header + Math.abs(this.length);
+}
+ASN1.prototype.fakeHover = function(current) {
+    this.node.className += " hover";
+    if (current)
+        this.head.className += " hover";
+}
+ASN1.prototype.fakeOut = function(current) {
+    var re = / ?hover/;
+    this.node.className = this.node.className.replace(re, "");
+    if (current)
+        this.head.className = this.head.className.replace(re, "");
+}
+ASN1.prototype.toHexDOM_sub = function(node, className, stream, start, end) {
+    if (start >= end)
+        return;
+    var sub = document.createElement("span");
+    sub.className = className;
+    sub.appendChild(document.createTextNode(
+        stream.hexDump(start, end)));
+    node.appendChild(sub);
+}
+ASN1.prototype.toHexDOM = function(root) {
+    var node = document.createElement("span");
+    node.className = 'hex';
+    if (root == undefined) root = node;
+    this.head.hexNode = node;
+    this.head.onmouseover = function() { this.hexNode.className = "hexCurrent"; }
+    this.head.onmouseout  = function() { this.hexNode.className = "hex"; }
+    node.asn1 = this;
+    node.onmouseover = function() {
+        var current = !root.selected;
+        if (current) {
+            root.selected = this.asn1;
+            this.className = "hexCurrent";
+        }
+        this.asn1.fakeHover(current);
+    }
+    node.onmouseout  = function() {
+        var current = (root.selected == this.asn1);
+        this.asn1.fakeOut(current);
+        if (current) {
+            root.selected = null;
+            this.className = "hex";
+        }
+    }
+    this.toHexDOM_sub(node, "tag", this.stream, this.posStart(), this.posStart() + 1);
+    this.toHexDOM_sub(node, (this.length >= 0) ? "dlen" : "ulen", this.stream, this.posStart() + 1, this.posContent());
+    if (this.sub == null)
+        node.appendChild(document.createTextNode(
+            this.stream.hexDump(this.posContent(), this.posEnd())));
+    else if (this.sub.length > 0) {
+        var first = this.sub[0];
+        var last = this.sub[this.sub.length - 1];
+        this.toHexDOM_sub(node, "intro", this.stream, this.posContent(), first.posStart());
+        for (var i = 0, max = this.sub.length; i < max; ++i)
+            node.appendChild(this.sub[i].toHexDOM(root));
+        this.toHexDOM_sub(node, "outro", this.stream, last.posEnd(), this.posEnd());
+    }
+    return node;
+}
+ASN1.decodeLength = function(stream) {
+    var buf = stream.get();
+    var len = buf & 0x7F;
+    if (len == buf)
+        return len;
+    if (len > 3)
+        throw "Length over 24 bits not supported at position " + (stream.pos - 1);
+    if (len == 0)
+        return -1; // undefined
+    buf = 0;
+    for (var i = 0; i < len; ++i)
+        buf = (buf << 8) | stream.get();
+    return buf;
+}
+ASN1.hasContent = function(tag, len, stream) {
+    if (tag & 0x20) // constructed
+        return true;
+    if ((tag < 0x03) || (tag > 0x04))
+        return false;
+    var p = new Stream(stream);
+    if (tag == 0x03) p.get(); // BitString unused bits, must be in [0, 7]
+    var subTag = p.get();
+    if ((subTag >> 6) & 0x01) // not (universal or context)
+        return false;
+    try {
+        var subLength = ASN1.decodeLength(p);
+        return ((p.pos - stream.pos) + subLength == len);
+    } catch (exception) {
+        return false;
+    }
+}
+ASN1.decode = function(stream) {
+    if (!(stream instanceof Stream))
+        stream = new Stream(stream, 0);
+    var streamStart = new Stream(stream);
+    var tag = stream.get();
+    var len = ASN1.decodeLength(stream);
+    var header = stream.pos - streamStart.pos;
+    var sub = null;
+    if (ASN1.hasContent(tag, len, stream)) {
+        // it has content, so we decode it
+        var start = stream.pos;
+        if (tag == 0x03) stream.get(); // skip BitString unused bits, must be in [0, 7]
+        sub = [];
+        if (len >= 0) {
+            // definite length
+            var end = start + len;
+            while (stream.pos < end)
+                sub[sub.length] = ASN1.decode(stream);
+            if (stream.pos != end)
+                throw "Content size is not correct for container starting at offset " + start;
+        } else {
+            // undefined length
+            try {
+                for (;;) {
+                    var s = ASN1.decode(stream);
+                    if (s.tag == 0)
+                        break;
+                    sub[sub.length] = s;
+                }
+                len = start - stream.pos;
+            } catch (e) {
+                throw "Exception while decoding undefined length content: " + e;
+            }
+        }
+    } else
+        stream.pos += len; // skip content
+    return new ASN1(streamStart, header, len, tag, sub);
+}
+/*
+ASN1.test = function() {
+    var test = [
+        { value: [0x27],                   expected: 0x27     },
+        { value: [0x81, 0xC9],             expected: 0xC9     },
+        { value: [0x83, 0xFE, 0xDC, 0xBA], expected: 0xFEDCBA },
+    ];
+    for (var i = 0, max = test.length; i < max; ++i) {
+        var pos = 0;
+        var stream = new Stream(test[i].value, 0);
+        var res = ASN1.decodeLength(stream);
+        if (res != test[i].expected)
+            document.write("In test[" + i + "] expected " + test[i].expected + " got " + res + "\n");
+    }
+}*/