I use spongycastle. I downloaded byte array certificate from webservice in android app (I think is base64 byte array) and want to display it on screen. I wrote below code but It does not work and c variable is null.
in addition I don't know how to display it on screen.
SoapObject result = (SoapObject)envelope.bodyIn;
if(result != null)
{
Object cert= result.getProperty(0);
InputStream is = new ByteArrayInputStream(cert.toString().getBytes());
CertificateFactory cf = CertificateFactory.getInstance("X.509","BC");
java.security.cert.Certificate c = cf.generateCertificate(is);
X509Certificate t = (X509Certificate) c;
System.out.println("ca=" + t.getSubjectDN());
}
Probably cert.toString().getBytes() is the problem. A certificate is encoded in binary format. To build it you need a byte array, not a string converted to bytes.
Ensure in which format are you receiving the certificate in order to transform it into binary. If you think that the certificate is encoded in base64, decode it in this way
byte[] data = Base64.decode(base64, Base64.DEFAULT);
Note also the Java Security API Provider name for SpongyCastle is SC rather than BC
To display a text you need for example to set the contento of a TextView inside an Activity or Fragment. I suggest you to get a tutorial first
Related
I want to save some of my sensitive data (string) in keyStore. I found that keyStore only accepts secretKey objects. But, I'm not able to store it and and retreive it later using keyChain callback by using the alias name of the secretKey
Any help will be appreciated..!
I think you are looking something like MD5. An MD5 hash is created by taking a string of an any length and encoding it into a 128-bit fingerprint. Encoding the same string using the MD5 algorithm will always result in the same 128-bit hash output. MD5 hashes are commonly used with smaller strings when storing passwords, credit card numbers or other sensitive data in databases such as the popular MySQL. This tool provides a quick and easy way to encode an MD5 hash from a simple string of up to 256 characters in length.
MD5 hashes are also used to ensure the data integrity of files. Because the MD5 hash algorithm always produces the same output for the same given input, users can compare a hash of the source file with a newly created hash of the destination file to check that it is intact and unmodified.
Hashing String with MD5:
public class JavaMD5Hash {
public static void main(String[] args) {
String password = "MyPassword123";
System.out.println("MD5 in hex: " + md5(password));
System.out.println("MD5 in hex: " + md5(null));
//= d41d8cd98f00b204e9800998ecf8427e
System.out.println("MD5 in hex: "
+ md5("The quick brown fox jumps over the lazy dog"));
//= 9e107d9d372bb6826bd81d3542a419d6
}
public static String md5(String input) {
String md5 = null;
if(null == input) return null;
try {
//Create MessageDigest object for MD5
MessageDigest digest = MessageDigest.getInstance("MD5");
//Update input string in message digest
digest.update(input.getBytes(), 0, input.length());
//Converts message digest value in base 16 (hex)
md5 = new BigInteger(1, digest.digest()).toString(16);
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
return md5;
}
}
referance :
http://viralpatel.net/blogs/java-md5-hashing-salting-password/
https://www.mkyong.com/java/java-md5-hashing-example/
http://www.asjava.com/core-java/java-md5-example/
you can use shared preferance which is very easy to handle also.
https://developer.android.com/training/basics/data-storage/shared-preferences.html
Android Shared preferences example
I want to append a line of text to an existing Azure cloud block blob from an Android device.
In VB.Net I would AcquireLease, getBlockBlobReference, DownloadToFile, add the line on the local files system, UploadToFile, ReleaseLease . Simple and secure, if a bit long-winded.
In Android, it looks a little more tricky. At the moment, my best solution is this:
CloudBlockBlob blob1=container.getBlockBlobReference(chosenOne+".txt");
String proposedLeaseId1 = UUID.randomUUID().toString();
OperationContext operationContext1 = new OperationContext();
blob1.acquireLease(15, proposedLeaseId1, null /*access condition*/,null/* BlobRequestOptions */, operationContext1);
AccessCondition condition = new AccessCondition();
condition.setLeaseID(proposedLeaseId1);
BlobInputStream blobIn = blob1.openInputStream();
blob1.downloadAttributes();
long blobLengthToUse = blob1.getProperties().getLength();
byte[] result = new byte[(int) blobLengthToUse];
blob1.downloadToByteArray(result,0);
blobIn.close();
CloudBlockBlob blob1 = container.getBlockBlobReference(chosenOne+".txt");
String proposedLeaseId1 = UUID.randomUUID().toString();
OperationContext operationContext1 = new OperationContext();
blob1.acquireLease(15, proposedLeaseId1, null /*access condition*/,null/* BlobRequestOptions */, operationContext1);
AccessCondition condition = new AccessCondition();
condition.setLeaseID(proposedLeaseId1);
BlobInputStream blobIn = blob1.openInputStream();
blob1.downloadAttributes();
long blobLengthToUse = blob1.getProperties().getLength();
byte[] result = new byte[(int) blobLengthToUse];
blob1.downloadToByteArray(result,0);
blobIn.close();
blob1.deleteIfExists(DeleteSnapshotsOption.NONE,condition, null, operationContext1);
BlobOutputStream blobOut = blob1.openOutputStream();
//this is a byte by byte write ...
//which is fine ... but no use if you want to replace ...
/*int next = blobIn.read();
while (next != -1) {
blobOut.write(next);
next = blobIn.read();
}*/
blobOut.write(result);
String strTemp="This is just a test string";
blobOut.write(strTemp.getBytes());
blobOut.close();
Apart from being extremely long-winded, I am concerned that as soon as I delete the blob, the lease will go and that I may hit integrity issues. I would appreciate any help in making this code simpler and more secure. I know that Microsoft are planning to introduce append blobs in 3Q 2015, but I want to implement this now.
You can call PutBlock to upload the appended content (the maximum size of each block is 4MB, so please split the appended content into blocks if required), and then call PutBlockList on this blob by passing in the previously committed blocks plus and newly appended blocks.
Does anyone know how to compress Ti.Utils.base64encode??
for example i have this code :
uploadFile = Ti.Filesystem.getFile(pathFile, listing[_fileCtr].toString());
uploadFileName = listing[_fileCtr].toString();
encodedFile = Ti.Utils.base64encode(uploadFile.read()).toString();
//Send Image to .NET web service
And this is the method in my web services for decompressing image from titanium (if i can compress my image before):
static byte[] Decompress(byte[] input)
{
using (MemoryStream output = new MemoryStream(input))
{
using (GZipStream zip = new GZipStream(output, CompressionMode.Decompress))
{
List<byte> bytes = new List<byte>();
int b = zip.ReadByte();
while (b != -1)
{
bytes.Add((byte)b);
b = zip.ReadByte();
}
return bytes.ToArray();
}
}
Until now, i can't find some method for compressing my byte array so i can decompress them using my .NET method..
If u guys have any information about my problem, please tell me..
Many thanks.. :)
In .Net you can use System.Convert.FromBase64String to converts the specified string, which encodes binary data as base-64 digits, to an equivalent 8-bit unsigned integer array.
System.Convert.FromBase64String(encodedString);
I am having problems verifying a signature which I've just created. After signing I first convert the signature to text using Base64 and as a test I wanted to verify that I can decode the Base64 and verify the signature. This fails. Here is some code without the error handling.
I have my keypair:
DSAPrivateKey privateKey = (DSAPrivateKey) keyPair.getPrivate();
DSAPublicKey publicKey = (DSAPublicKey) keyPair.getPublic();
Now I sign some text and print to log output - it seems fine:
String text = "test";
Signature signer = null;
signer = Signature.getInstance(privateKey.getAlgorithm());
SignedObject signedObject = null;
signedObject = new SignedObject(text, privateKey, signer);
String print_signature = Base64.encodeToString(signedObject.getSignature(), Base64.DEFAULT);
System.out.println("Base64 Signature: " + print_signature);
Now I verify the signature using the SignedObject object created above and not the Base64. This is successful:
Signature verifier = null;
verifier = Signature.getInstance(publicKey.getAlgorithm());
boolean b = signedObject.verify(publicKey, verifier));
For my app I will only have the public certificate of the signer and the Base64 encoded string so I must verify the signature using these parameters only and can therefore AFAIK not use a SignedObject object. I used the Signature object:
Signature verifier1 = null;
verifier1 = Signature.getInstance(publicKey.getAlgorithm());
verifier1.initVerify(publicKey);
verifier1.update(text.getBytes()); // sorry I forgot this in original posting
byte[] sig1 = Base64.decode(print_signature, Base64.DEFAULT);
b = verifier1.verify(sig1));
This verification always fails (b = false).
Why are you using the SignedObject in the first place? What does it buy you? As for the verify failure, make sure that you get the same bytes after transmission/receiving. Are you sending/receiving in the same encoding? Is someone modifying the string?
I have a text file which contains data I need to preload into a SQLite database. I saved in in res/raw.
I read the whole file using readTxtFromRaw(), then I use the StringTokenizer class to process the file line by line.
However the String returned by readTxtFromRaw does not show foreign characters that are in the file. I need these as some of the text is Spanish or French. Am I missing something?
Code:
String fileCont = new String(readTxtFromRaw(R.raw.wordstext));
StringTokenizer myToken = new StringTokenizer(fileCont , "\t\n\r\f");
The readTxtFromRaw method is:
private String readTxtFromRaw(Integer rawResource) throws IOException
{
InputStream inputStream = mCtx.getResources().openRawResource(rawResource);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
int i = inputStream.read();
while (i != -1)
{
byteArrayOutputStream.write(i);
i = inputStream.read();
}
inputStream.close();
return byteArrayOutputStream.toString();
}
The file was created using Eclipse, and all characters appear fine in Eclipse.
Could this have something to do with Eclipse itself? I set a breakpoint and checked out myToken in the Watch window. I tried to manually replace the weird character for the correct one (for example í, or é), and it would not let me.
Have you checked the several encodings?
what's the encoding of your source file?
what's the encoding of your output stream?
the byteArrayOutputStream.toString() converts according to the platform's default character encoding. So I guess it will strip the foreign characters or convert them in a way that they are not displayed in your output.
Have you already tried to use byteArrayOutputStream.toString(String enc)? Try "UTF-8" or "iso-8859-1" or "UTF-16" for the encoding.