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How to correctly encode and decode a string in Base64?

I want to encode a string in Base64 for later decoding it. I encode it doing this:
public static String encryptString(String string) {
byte[] bytesEncoded = Base64.getEncoder().encode(string.getBytes());
return (new String(bytesEncoded));
}
Then, the encoded string is stored on disk using UTF-8. After restarting the application, the encoded string is readed from disk and I'm trying to decode the string using this:
public static String decryptString(String string) {
byte[] valueDecoded = Base64.getDecoder().decode(string);
return (new String(valueDecoded));
}
Something is wrong because it is giving me this exception:
java.lang.IllegalArgumentException: Illegal base64 character d
at java.base/java.util.Base64$Decoder.decode0(Base64.java:743)
at java.base/java.util.Base64$Decoder.decode(Base64.java:535)
at java.base/java.util.Base64$Decoder.decode(Base64.java:558)
This is a TRACE step by step
1º i encode this: {"configuration":{"shop":{"name":"","addressLine1":"","addressLine2":"","postalCode":"","city":"","country":"","phoneNumber":""}},"jointBets":[],"groups":[{"name":"Test","members":[]}]}
into this: eyJjb25maWd1cmF0aW9uIjp7InNob3AiOnsibmFtZSI6IiIsImFkZHJlc3NMaW5lMSI6IiIsImFkZHJlc3NMaW5lMiI6IiIsInBvc3RhbENvZGUiOiIiLCJjaXR5IjoiIiwiY291bnRyeSI6IiIsInBob25lTnVtYmVyIjoiIn19LCJqb2ludEJldHMiOltdLCJncm91cHMiOlt7Im5hbWUiOiJUZXN0IiwibWVtYmVycyI6W119XX0=
2º i store it on disk in utf8
3º i retreive it from disk and it's this string:
eyJjb25maWd1cmF0aW9uIjp7InNob3AiOnsibmFtZSI6IiIsImFkZHJlc3NMaW5lMSI6IiIsImFkZHJlc3NMaW5lMiI6IiIsInBvc3RhbENvZGUiOiIiLCJjaXR5IjoiIiwiY291bnRyeSI6IiIsInBob25lTnVtYmVyIjoiIn19LCJqb2ludEJldHMiOltdLCJncm91cHMiOlt7Im5hbWUiOiJUZXN0IiwibWVtYmVycyI6W119XX0=
4º i decode it and get the exception.

The old Base64 utility add linebreaks every 76 characters in Java8.
The result looks like that:
/9j/4AAQSkZJRgABAgAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a
HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy
MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCABkAGQDASIA
AhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQA
AAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3
ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWm
...
It seems that this behaviour changed with some version. At least with Java11 the decoder is not accepting line-breaks anymore.
To avoid the problem you could change you method
public static String decryptString(String string) {
byte[] valueDecoded = Base64.getDecoder().decode(string.replace("\n","").replace("\r","");
return new String(valueDecoded);
}

Then, the encoded string is stored on disk using UTF-8. After
restarting the application, the encoded string is readed from disk and
I'm trying to decode the string using this:
This seems to be a point of failure. Most likely your problem is OS/JDK dependent Apparently the following code seems to work well for me (Win 7, latest JDK 1.8):
public static void main(String[] args) throws IOException {
String source = "{\"configuration\":{\"shop\":{\"name\":\"España\",\"addressLine1\":\"\",\"addressLine2\":\"\"," +
"\"postalCode\":\"\",\"city\":\"\",\"country\":\"\",\"phoneNumber\":\"\"}},\"jointBets\":[]," +
"\"groups\":[{\"name\":\"Test\",\"members\":[]}]}";
// Encode string
String encoded = encryptString(source);
System.out.println("Base64 encoded: " + encoded);
// Temp Dir
String tempDir = System.getProperty("java.io.tmpdir");
// Write to File
try (BufferedWriter writer = new BufferedWriter(new FileWriter(tempDir + "data.txt"))) {
writer.write(encoded);
}
// Read from File
Path path = Paths.get(tempDir + "data.txt");
Stream<String> lines = Files.lines(path);
String dataFromFile = lines.collect(Collectors.joining("\n"));
lines.close();
// Compare content
assert encoded.equals(dataFromFile);
// Decode string
String decoded = decryptString(dataFromFile);
System.out.println("Base64 decoded: " + decoded);
}
public static String encryptString(String string) {
byte[] bytesEncoded = Base64.getEncoder().encode(string.getBytes(StandardCharsets.UTF_8));
return new String(bytesEncoded);
}
public static String decryptString(String string) {
byte[] valueDecoded = Base64.getDecoder().decode(string);
return new String(valueDecoded);
}
Base64 encoded:
eyJjb25maWd1cmF0aW9uIjp7InNob3AiOnsibmFtZSI6IkVzcGHDsWEiLCJhZGRyZXNzTGluZTEiOiIiLCJhZGRyZXNzTGluZTIiOiIiLCJwb3N0YWxDb2RlIjoiIiwiY2l0eSI6IiIsImNvdW50cnkiOiIiLCJwaG9uZU51bWJlciI6IiJ9fSwiam9pbnRCZXRzIjpbXSwiZ3JvdXBzIjpbeyJuYW1lIjoiVGVzdCIsIm1lbWJlcnMiOltdfV19
Base64 decoded:
{"configuration":{"shop":{"name":"España","addressLine1":"","addressLine2":"","postalCode":"","city":"","country":"","phoneNumber":""}},"jointBets":[],"groups":[{"name":"Test","members":[]}]}

My guess is that you are not specifying a charset. Try running the below maybe with and without the charset specified for the String constructor to verify.
#Test
public void base64Test() throws Exception{
String string = "ABCDF";
byte[] bytesEncoded = Base64.getEncoder().encode(string.getBytes());
String encodedStr = (new String(bytesEncoded,Charset.forName("ISO-8859-1")));
System.out.println(encodedStr);
byte[] valueDecoded = Base64.getDecoder().decode(encodedStr);
String decodedStr = (new String(valueDecoded,Charset.forName("ISO-8859-1")));
System.out.println(decodedStr);
}

Encoding without a String in Java

In the following method, how it is possible to return the Cp037 byte[] without creating a String object... maybe using some encode() methods and Charset?
public byte[] encodeCp037(byte[] bytes)
{
String str = null;
try
{
str = new String(bytes, "Cp037");
}
catch (UnsupportedEncodingException e)
{
throw new UnsupportedOperationException("Invalid encoding. Charset=Cp037.");
}
return str.getBytes();
}

This method can change encoding without creating a String.(Of course it has overhead but no String)
public static byte[] transform(byte[] bytes, String fromCharset, String toCharset) {
ByteBuffer byteBuffer = ByteBuffer.wrap(bytes);
CharBuffer charBuffer = Charset.forName(fromCharset).decode(byteBuffer);
ByteBuffer targetBuffer = Charset.forName(toCharset).encode(charBuffer);
return Arrays.copyOfRange(targetBuffer.array(), targetBuffer.position(), targetBuffer.limit());
}
And you can use it convert from cp037 to utf-8 for example.
byte[] cp037 = "123".getBytes("cp037");
byte[] utf8 = transform(cp037, "cp037", "utf8");
System.out.println(new String(utf8, "utf-8"));
This will print 123 and it was converted successfully.

JCPABE Encypt Decrypt String

I see the JCPABE project, but the methods that are in classes enable me to encrypt file or InputStream but not a simple Java string. How can I use these methods to encrypt/decrypt a string ? I have tried to convert the string in byte array but it doesn't work (i.e. String.getBytes("UTF_8"); same if i convert the String in an InputStream. How can I encrypt/decrypt a simple string?
Example:
My simple code:
String test="Message";
policy="newyork or losangeles";
Cpabe.encrypt(publickey, policy, test, test);
I have this message: The method encrypt(File, String, File, File) in the type Cpabe is not applicable for the arguments (File, String, String, String).
The function encrypt is this:
public static void encrypt(File publicKeyFile, String policy, File inputFile, File outputFile) throws IOException, AbeEncryptionException {
AbePublicKey publicKey = AbePublicKey.readFromFile(publicKeyFile);
try (BufferedInputStream in = new BufferedInputStream(new FileInputStream(inputFile));
BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outputFile))) {
encrypt(publicKey, policy, in, out);
}
I have changed the function in:
public static void encrypt(File publicKeyFile, String policy, String inputstr, String outputstr) throws IOException, AbeEncryptionException {
AbePublicKey publicKey = AbePublicKey.readFromFile(publicKeyFile);
try (String in = new String(inputstr);
String out = new String(outputstr)) {
encrypt(publicKey, policy, in, out);
}
}
but I have other message: The resource type String does not implement java.lang.AutoCloseable on the String in and String out; while on the encrypt I have these message: The method encrypt(AbePublicKey, String, InputStream, OutputStream) in the type Cpabe is not applicable for the arguments (AbePublicKey, String, String, String).
This is the function with the 2 InputStream parameters:
public static void encrypt(AbePublicKey publicKey, String policy, InputStream input, OutputStream output) throws AbeEncryptionException, IOException {
AbeEncrypted encrypted = encrypt(publicKey, policy, input);
encrypted.writeEncryptedData(output, publicKey);
}
and this is the writeEncryptedData method:
public void writeEncryptedData(OutputStream out, AbePublicKey publicKey) throws IOException {
AbeOutputStream abeOut = new AbeOutputStream(out, publicKey);
Version.writeToStream(abeOut);
cipher.writeToStream(abeOut);
abeOut.writeInt(iv.length);
abeOut.write(iv);
byte[] buffer = new byte[1024];
int len;
while ((len = dataStream.read(buffer)) != -1) {
abeOut.write(buffer, 0, len);
}
}

Your code can not because of various reasons. First you need an InputStream and OutputStream. To use a String you have to first convert it to byte[] and then to a stream.
In your function you defined something like a "out parameter" String outputstr. However Strings are immutable in Java, therefore you can not use it that way and change it's content. Use it as return value instead.
Third never ever try to convert byte[] to String using new String(<byte array>). This does not return a String with printable characters but a String with binary non-printable content. You have to encode it e.g. using base64. Before decrypting it you have to apply base64 decode.
public static String encrypt(File publicKeyFile, String policy, String inputstr) throws IOException, AbeEncryptionException {
AbePublicKey publicKey = AbePublicKey.readFromFile(publicKeyFile);
try (InputStream in = new ByteArrayInputStream(inputstr.getBytes(StandardCharsets.UTF_8);
ByteArrayOutputStream out = new ByteArrayOutputStream()) {
encrypt(publicKey, policy, in, out);
return Base64.getEncoder().encodeToString(out.toByteArray());
}
}

Why doesn't Base64 Encoding of a byte[] in Java work?

import java.io.*;
import java.nio.*;
import java.util.Base64;
import java.util.UUID;
import java.io.UnsupportedEncodingException;
public class Abc {
public static String readFileAsString(String filePath) throws IOException {
DataInputStream dis = new DataInputStream(new FileInputStream(filePath));
try {
long len = new java.io.File(filePath).length();
if (len > Integer.MAX_VALUE) throw new IOException("File " + filePath + " too large")
byte[] bytes = new byte[(int) len];
dis.readFully(bytes);
String ans = new String(bytes, "UTF-8");
return ans;
} finally {
dis.close();
}
}
public static void main(String args[]) throws IOException {
String base64encodedString = null;
FileOutputStream stream = new FileOutputStream("C:\\Users\\EMP142738\\Desktop\\New folder\\Readhjbdsdsefd.pdf");
String filePath = new String("C:\\Users\\EMP142738\\Desktop\\New folder\\Readers Quick Ref Card.pdf");
try {
base64encodedString = java.util.Base64.getUrlEncoder().encodeToString(new Abc().readFileAsString(filePath).getBytes("utf-8"));
} catch (IOException e) {
e.printStackTrace();
}
try {
byte[] base64decodedBytes = java.util.Base64.getUrlDecoder().decode(base64encodedString);
stream.write(base64decodedBytes);
} catch(IOException e){
e.printStackTrace();}
finally {
stream.close();
}//catch (FileNotFoundException e) {
// e.printStackTrace();
}
}
I'm trying to encode and decode a PDF file using Base64. What I'm doing is converting a PDF(Binary File) to a ByteArray, then returning the ByteArray as a string. I'm then encoding this string in Base64, using java.util.Base64. When I try to backtrack through the process, I'm able to convert a PDF(Binary File) but the File is corrupted/damaged. Also, the output file after the entire process ( Encode- Decode) is significantly larger than the input file. I expected that both of them would be of the same size. What am I doing wrong here?
Edit 1( 7/13/16):
In the main method, I modified the code as per Jim's suggestion.
I tried using Base64.encode(byte[] src) after reading the documentation of the same. However it keeps giving the error "cannot find symbol Base64.encode(byte[])". But I've used the encodetoString method from the same Class( java.util.Base64.Encoder). I'm unable to understand the issue here.
Here's the modified main method used after returning a byte[] from the readFileAsString method.
public void main(String args[]) throws IOException {
String filePath = new String("C:\\Users\\EMP142738\\Desktop\\New folder\\Readers Quick Ref Card.pdf");
byte[] src = new Abc().readFileAsString(filePath);
byte[] destination = Base64.encode(src);
}

The problem is in your flow
byte[] -> String -> base64 string
You need to omit the conversion to String and go directly:
byte[] -> base64 string
Converting to String will corrupt a binary stream as it involves a decode operation from the input character set to 16-bit Unicode characters.

Java convert string bytes to readable string [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Java Byte Array to String to Byte Array
I have a method called READ() that accept a String parameter. This string is already have been converted into bytes. All I want is to convert into a readable string.
public static String READ(final String data) throws UnsupportedEncodingException{
char[] temp = data.toCharArray();
byte[] bytes = new byte[temp.length];
int i = 0;
for(char c : temp){
bytes[i++] = (byte)c;
}
return new String(bytes, "UTF-8");
}
public static String SEND(String data) throws UnsupportedEncodingException{
return data.getBytes()+"";
}
Testing:
String msg = "testing !";
String msgBytes = null;
try {
msgBytes = SEND(msg);
} catch (UnsupportedEncodingException e2) {
e2.printStackTrace();
}
System.out.println( "SEND: " + msgBytes);
try {
System.out.println("RECEIVE: " + READ(msgBytes));
} catch (UnsupportedEncodingException e2) {
e2.printStackTrace();
}
And the OUTPUT IS:
SEND: [B#452467ec
RECEIVE: [B#452467ec

String has a constructor that takes byte[] as an argument.
String(byte[] bytes) --
Constructs a new String by decoding the specified array of bytes using the platform's default charset.
String(byte[] bytes, Charset charset) --
Constructs a new String by decoding the specified array of bytes using the specified charset.
So print it like this:
System.out.println(new String(msgBytes, "UTF-8"));
What you currently see is a default Object.toString() which prints a memory reference to the byte array (all arrays extend from Object).

You print a byte[] which is an Object, so it just prints the reference into memory of that Object because that's what the default implementation of toString() does.
You should print the String directly. Don't print its byte[] representation.
What you do in your code is to transform a String into byte[] and then back to String in the wrong way.