I have a website in asp.net 2.0, As I need to use CCNOW payment integration to make a payment but for this I'll have to send request to CCNOW in MD5 format but I can't able to generate my values to CCNOW MD5 format. So, could you please any one have a script/function that will convert given string into MD5?
MD5 isn't a "format," is a hashing algorithm. Use the MD5 class. Assuming you're using C#, it would look something like this:
static string getMd5Hash(string input)
{
// Create a new instance of the MD5CryptoServiceProvider object.
MD5 md5Hasher = MD5.Create();
// Convert the input string to a byte array and compute the hash.
byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));
// Create a new Stringbuilder to collect the bytes
// and create a string.
StringBuilder sBuilder = new StringBuilder();
// Loop through each byte of the hashed data
// and format each one as a hexadecimal string.
for (int i = 0; i < data.Length; i++)
{
sBuilder.Append(data[i].ToString("x2"));
}
// Return the hexadecimal string.
return sBuilder.ToString();
}
public static string GetMD5(string value) {
MD5 md5 = MD5.Create();
byte[] md5Bytes = System.Text.Encoding.Default.GetBytes(value);
byte[] cryString = md5.ComputeHash(md5Bytes);
string md5Str = string.Empty;
for (int i = 0; i < cryString.Length; i++) {
md5Str += cryString[i].ToString("X");
}
return md5Str;
}
Call it with:
GetMD5(stringToConvert);
Related
Have been stringbuilding CSV files for ages on MVC applications just fine, until now.
One mistake made me generate a CSV string bigger then the system can handle in memory, so i have been searching the web for any solution on minifing a string that could be reconstructed back on client.
So far i have been doing this:
StringBUilder sb = new StringBuilder();
foreach(stuff in manyEnumerableStuff)
sb.Append(stuff);
return csv.ToString().ToBase64();
public static string ToBase64(this string value) => Convert.ToBase64String(Encoding.Default.GetBytes(value));
The application can handle .ToString() in this HUGE case just "fine", but it fails without creating excpetions at .ToBase64String(Encoding.Default.GetBytes(value));
This only happens on huge strings because from what i know, base64 will make the string 33% bigger.
Compressed json can't solve this problem, since this happens on server side.
So I have gonne on search to minify or compress this string, but it still need to be a string and can be converted on client site Angular application.
I have found this:
public static string compress(this string big) {
var bytes = Encoding.Default.GetBytes(big);
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream()) {
using (var gs = new GZipStream(mso, CompressionMode.Compress)) {
//msi.CopyTo(gs);
CopyTo(msi, gs);
}
return mso.ToArray().ToString();
}
}
private static void CopyTo(Stream src, Stream dest) {
byte[] bytes = new byte[4096];
int cnt;
while ((cnt = src.Read(bytes, 0, bytes.Length)) != 0) {
dest.Write(bytes, 0, cnt);
}
}
but I think there is no sense at all, because i can't put byte[] on json value as string without converting it back.
Is it possible to compress plain Pipe separated values that represents a .CSV file after getting the string from StringBuilder()?
I have tried GC.collect() right after parsing SB to string but still broke the application.
I'm on .Net Core 2.1, Linux server.
In the applications I'm developing I need to store data for Customer,Products and their Prices.
In order to persist that data I use RMS, but knowing that RMS doesn't support object serializing directly and since that data I read already comes in json format, I store every JSONObject as its string version, like this:
rs = RecordStore.openRecordStore(mRecordStoreName, true);
JSONArray jsArray = new JSONArray(data);
for (int i = 0; i < jsArray.length(); i++) {
JSONObject jsObj = jsArray.getJSONObject(i);
stringJSON = jsObj.toString();
addRecord(stringJSON, rs);
}
The addRecord Method
public int addRecord(String stringJSON, RecordStore rs) throws JSONException,RecordStoreException {
int id = -1;
byte[] raw = stringJSON.getBytes();
id= rs.addRecord(raw, 0, raw.length);
return id;
}
So I have three RecordStores (Customer,Products and their Prices) and for each of them I do the save as shown above to save their corresponding data.
I know this might be a possible to solution, but I'm sure there's gotta be a better implementation. Even more,considering that over those three "tables" I'm going to perform searching, sorting,etc.
In those cases, having to deserialize before proceeding to search or sort doesn't seem a very good idea.
That's why I want to ask you guys. In your experience, how do store custom objects in RMS in way that is easy to work with them later??
I really appreciate all your comments and suggestions.
EDIT
It seems that it's easier to work with records when you define a fixed max length for each field. So here's what I tried:
1) First all, this is the class I use to retrieve the values from the record store:
public class Customer {
public int idCust;
public String name;
public String IDNumber;
public String address;
}
2) This is the code I use to save every jsonObject to the record store:
RecordStore rs = null;
try {
rs = RecordStore.openRecordStore(mRecordStoreName, true);
JSONArray js = new JSONArray(data);
for (int i = 0; i < js.length(); i++) {
JSONObject jsObj = js.getJSONObject(i);
byte[] record = packRecord(jsObj);
rs.addRecord(record, 0, record.length);
}
} finally {
if (rs != null) {
rs.closeRecordStore();
}
}
The packRecord method :
private byte[] packRecord(JSONObject jsonObj) throws IOException, JSONException {
ByteArrayOutputStream raw = new ByteArrayOutputStream();
DataOutputStream out = new DataOutputStream(raw);
out.writeInt(jsonObj.getInt("idCust"));
out.writeUTF(jsonObj.getString("name"));
out.writeUTF(jsonObj.getString("IDNumber"));
out.writeUTF(jsonObj.getString("address"));
return raw.toByteArray();
}
3) This is how I pull all the records from the record store :
RecordStore rs = null;
RecordEnumeration re = null;
try {
rs = RecordStore.openRecordStore(mRecordStoreName, true);
re = rs.enumerateRecords(null, null, false);
while (re.hasNextElement()) {
Customer c;
int idRecord = re.nextRecordId();
byte[] record = rs.getRecord(idRecord);
c = parseRecord(record);
//Do something with the parsed object (Customer)
}
} finally {
if (re != null) {
re.destroy();
}
if (rs != null) {
rs.closeRecordStore();
}
}
The parseRecord Method :
private Customer parseRecord(byte[] record) throws IOException {
Customer cust = new Customer();
ByteArrayInputStream raw = new ByteArrayInputStream(record);
DataInputStream in = new DataInputStream(raw);
cust.idCust = in.readInt();
cust.name = in.readUTF();
cust.IDNumber = in.readUTF();
cust.address = in.readUTF();
return cust;
}
This is how I implemented what Mister Smith suggested(hope it's what he had in mind). However, I'm still not very sure about how to implement the searchs.
I almost forget to mention that before I made theses changes to my code, the size of my RecordStore was 229048 bytes, now it is only 158872 bytes :)
RMS is nothing of the sort of a database. You have to think of it as a record set, where each record is a byte array.
Because of this, it is easier to work with it when you define a fixed max length for each field in the record. For instance, a record could be some info about a player in a game (max level reached, score, player name, etc). You could define the level field as 4 bytes long (int), then a score field of 8 bytes (a long), then the name as a 100 bytes field (string). This is tricky because strings usually will be of variable length, but you would probably like to have a fixed max length for this field, and if some string is shorter than that, you'd use a string terminator char to delimite it. (This example is actually bad because the string is the last field, so it would have been easier to keep it variable length. Just imagine you have several consecutive fields of type string.)
To help you with serialization/deserialization, you can use DataOutputstream and DataInputStream. With these classes you can read/write strings in UTF and they will insert the string delimiters for you. But this means that when you need a field, as you don't know exactly where it is located, you'll have to read the array up to that position first.
The advantage of fixed lengths is that you could later use a RecordFilter and if you wanted to retrieve recors of players that have reached a score greater than 10000, you can look at the "points" field in exactly the same position (an offset of 4 bytes from the start of the byte array).
So it's a tradeoff. Fixed lengths means faster access to fields (faster searches), but potential waste of space. Variable lengths means minimum storage space but slower searches. What is best for your case will depend on the number of records and the kind of searches you need.
You have a good collection of tutorials in the net. Just to name a few:
http://developer.samsung.com/java/technical-docs/Java-ME-Record-Management-System
http://developer.nokia.com/community/wiki/Persistent_Data_in_Java_ME
is it possible or is there any overload to get a less than 32 characters of GUID ?
currently i am using this statement but its giving me error
string guid = new Guid("{dddd-dddd-dddd-dddd}").ToString();
i want a key of 20 characters
You can use a ShortGuid. Here is an example of an implementation.
It's nice to use ShortGuids in URLs or other places visible to an end user.
The following code:
Guid guid = Guid.NewGuid();
ShortGuid sguid1 = guid; // implicitly cast the guid as a shortguid
Console.WriteLine( sguid1 );
Console.WriteLine( sguid1.Guid );
Will give you this output:
FEx1sZbSD0ugmgMAF_RGHw
b1754c14-d296-4b0f-a09a-030017f4461f
This is the code for an Encode and Decode method:
public static string Encode(Guid guid)
{
string encoded = Convert.ToBase64String(guid.ToByteArray());
encoded = encoded
.Replace("/", "_")
.Replace("+", "-");
return encoded.Substring(0, 22);
}
public static Guid Decode(string value)
{
value = value
.Replace("_", "/")
.Replace("-", "+");
byte[] buffer = Convert.FromBase64String(value + "==");
return new Guid(buffer);
}
Use Jeff Attwood's ASCII85...
http://www.codinghorror.com/blog/2005/10/equipping-our-ascii-armor.html
and
http://www.codinghorror.com/blog/2005/10/c-implementation-of-ascii85.html
I am doing encryption and decryption using AES Algorithm with bouncy castle
My encryption and decryption works ok but it gives me error when my plain text size is bigger
even sometimes it is giving non decrypted data
public static boolean setEncryptionKey(String keyText)
{
byte[] keyBytes = keyText.getBytes();
key = new KeyParameter(keyBytes);
engine = new AESFastEngine();
cipher = new PaddedBufferedBlockCipher(engine);
return true;
}
Encryption:
public static String encryptString(String plainText)
{
byte[] plainArray = plainText.getBytes();
cipher.init(true, key);
byte[] cipherBytes = new byte[cipher.getOutputSize(plainArray.length)];
int cipherLength = cipher.processBytes(plainArray, 0, plainArray.length, cipherBytes, 0);
cipher.doFinal(cipherBytes, cipherLength);
String cipherString = new String(cipherBytes);
return cipherString;
}
Decryption:
public static String decryptString(String encryptedText)
{
byte[] cipherBytes = encryptedText.getBytes();
cipher.init(false, key);
byte[] decryptedBytes = new byte[cipher.getOutputSize(cipherBytes.length)];
int decryptedLength = cipher.processBytes(cipherBytes, 0, cipherBytes.length, decryptedBytes, 0);
cipher.doFinal(decryptedBytes, decryptedLength);
String decryptedString = new String(decryptedBytes);
int index = decryptedString.indexOf("\u0000");
if (index >= 0)
{
decryptedString = decryptedString.substring(0, index);
}
return decryptedString;
}
This decryption is giving me following error
org.bouncycastle.crypto.InvalidCipherTextException: pad block corrupted
at org.bouncycastle.crypto.paddings.PKCS7Padding.padCount(+30)
at org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher.doFinal(+190)
at com.NewCrypto.decryptString(NewCrypto.java:103)
at com.New_Midlet.startApp(New_Midlet.java:23)
at javax.microedition.midlet.MIDletProxy.startApp(MIDletProxy.java:44)
at com.sun.midp.midlet.Scheduler.schedule(Scheduler.java:375)
at com.sun.midp.main.Main.runLocalClass(Main.java:477)
at com.sun.midp.main.Main.main(+80)
what could be the problem ?
The line
String cipherString = new String(cipherBytes);
is a bug. cipherBytes is a byte array with arbitrary values and cannot be converted to a string using any of the Java string decoders. You should just send/save the cipher as a byte array. If you must make it a string then you'll have to use an encoder. Base64 encoders are often used, as are Base16 (hex). You can use the Apache Commons Codec or my favorite, the Harder Base64 codec.
I get string messages from the clients which needs to be authenticated in the server.
I need to ensure that I (the server) got the exact string content which was sent by the client. I don't care about the client identity. Just the message.
I thought of using hashcode or CRC algorithm.
Do you have any suggestions/best practices for it?
Thanks a lot,
Adi Barda
To make certain the string is identical, then yes, a hash will do the job. The only problem you will encounter is that if the server has nothing to match to, all you will have is that the string you have is the same as the string that was hashed.
Any language you are using in particular?
Here's an example in C#, which hashes a string then converts into Base64:
public static string QHash(string str)
{
SHA512 SHA512HashCreator = SHA512.Create();
byte[] EncryptedData = SHA512HashCreator.ComputeHash(Encoding.UTF8.GetBytes(str));
StringBuilder qhash = new StringBuilder();
for (int i = 0; i < EncryptedData.Length; i++)
{
qhash.Append(EncryptedData[i].ToString("X2"));
}
return qhash.ToString().ToUpper();
}