I'm trying to send a confirmation email after user registration. I'm using the JavaMail library for this purpose and the Java 8 Base64 util class.

I'm encoding user emails in the following way:

byte[] encodedEmail = Base64.getUrlEncoder().encode(user.getEmail().getBytes(StandardCharsets.UTF_8));
Multipart multipart = new MimeMultipart();
InternetHeaders headers = new InternetHeaders();
headers.addHeader("Content-type", "text/html; charset=UTF-8");
String confirmLink = "Complete your registration by clicking on following"+ "\n<a href='" + confirmationURL + encodedEmail + "'>link</a>";
MimeBodyPart link = new MimeBodyPart(headers,
confirmLink.getBytes("UTF-8"));
multipart.addBodyPart(link);

where confirmationURL is:

private final static String confirmationURL = "";

And then decoding this in ConfirmRegistrationCommand in such way:

 String encryptedEmail = request.getParameter("ID"); String decodedEmail = new String(Base64.getUrlDecoder().decode(encryptedEmail), StandardCharsets.UTF_8); RepositoryFactory repositoryFactory = RepositoryFactory .getFactoryByName(FactoryType.MYSQL_REPOSITORY_FACTORY); UserRepository userRepository = repositoryFactory.getUserRepository(); User user = userRepository.find(decodedEmail); if (user.getEmail().equals(decodedEmail)) { user.setActiveStatus(true); return Path.WELCOME_PAGE; } else { return Path.ERROR_PAGE; }

And when I'm trying to decode:

I'm getting java.lang.IllegalArgumentException: Illegal base64 character 5b.

I tried to use basic Encode/Decoder (not URL ones) with no success.

SOLVED:

The problem was the next - in the line:

 String confirmLink = "Complete your registration by clicking on following"+ "\n<a href='" + confirmationURL + encodedEmail + "'>link</a>";

I'm calling toString on an array of bytes, so I should do the following:

String encodedEmail = new String(Base64.getEncoder().encode( user.getEmail().getBytes(StandardCharsets.UTF_8)));

Thanks to Jon Skeet and ByteHamster.

5

6 Answers

Your encoded text is [B@6499375d. That is not Base64, something went wrong while encoding. That decoding code looks good.

Use this code to convert the byte[] to a String before adding it to the URL:

String encodedEmailString = new String(encodedEmail, "UTF-8");
// ...
String confirmLink = "Complete your registration by clicking on following" + "\n<a href='" + confirmationURL + encodedEmailString + "'>link</a>";

1

I encountered this error since my encoded image started with data:image/png;base64,iVBORw0....

This answer led me to the solution:

String partSeparator = ",";
if (data.contains(partSeparator)) { String encodedImg = data.split(partSeparator)[1]; byte[] decodedImg = Base64.getDecoder().decode(encodedImg.getBytes(StandardCharsets.UTF_8)); Path destinationFile = Paths.get("/path/to/imageDir", "myImage.png"); Files.write(destinationFile, decodedImg);
}

That code removes the meta data in front of the Base64-encoded image and passes the Base64 string to Java's Base64.Decoder to get the image as bytes.

0

Just use the below code to resolve this:

JsonObject obj = Json.createReader(new ByteArrayInputStream(Base64.getDecoder().decode(accessToken.split("\\.")[1]. replace('-', '+').replace('_', '/')))).readObject();

In the above code replace('-', '+').replace('_', '/') did the job. For more details see the . I understood the problem from the part of the code got from that link:

function url_base64_decode(str) { var output = str.replace(/-/g, '+').replace(/_/g, '/'); switch (output.length % 4) { case 0: break; case 2: output += '=='; break; case 3: output += '='; break; default: throw 'Illegal base64url string!'; } var result = window.atob(output); //polifyll try{ return decodeURIComponent(escape(result)); } catch (err) { return result; }
}

The Base64.Encoder.encodeToString method automatically uses the ISO-8859-1 character set.

For an encryption utility I am writing, I took the input string of cipher text and Base64 encoded it for transmission, then reversed the process. Relevant parts shown below. NOTE: My file.encoding property is set to ISO-8859-1 upon invocation of the JVM so that may also have a bearing.

static String getBase64EncodedCipherText(String cipherText) { byte[] cText = cipherText.getBytes(); // return an ISO-8859-1 encoded String return Base64.getEncoder().encodeToString(cText);
}
static String getBase64DecodedCipherText(String encodedCipherText) throws IOException { return new String((Base64.getDecoder().decode(encodedCipherText)));
}
public static void main(String[] args) { try { String cText = getRawCipherText(null, "Hello World of Encryption..."); System.out.println("Text to encrypt/encode: Hello World of Encryption..."); // This output is a simple sanity check to display that the text // has indeed been converted to a cipher text which // is unreadable by all but the most intelligent of programmers. // It is absolutely inhuman of me to do such a thing, but I am a // rebel and cannot be trusted in any way. Please look away. System.out.println("RAW CIPHER TEXT: " + cText); cText = getBase64EncodedCipherText(cText); System.out.println("BASE64 ENCODED: " + cText); // There he goes again!! System.out.println("BASE64 DECODED: " + getBase64DecodedCipherText(cText)); System.out.println("DECODED CIPHER TEXT: " + decodeRawCipherText(null, getBase64DecodedCipherText(cText))); } catch (Exception e) { e.printStackTrace(); }
}

The output looks like:

Text to encrypt/encode: Hello World of Encryption...
RAW CIPHER TEXT: q$;�C�l��<8��U���X[7l
BASE64 ENCODED: HnEPJDuhQ+qDbInUCzw4gx0VDqtVwef+WFs3bA==
BASE64 DECODED: q$;�C�l��<8��U���X[7l``
DECODED CIPHER TEXT: Hello World of Encryption...

4

I got this error for my Linux Jenkins slave. I fixed it by changing from the node from "Known hosts file Verification Strategy" to "Non verifying Verification Strategy".

I have added my failures and findings and how I've overcome this issue here. I've been working on JASYPT ciphering with SpringBoot recently and there were many issues I encountered and fixed them along the way. For this question of Illegal character exception, I have already logged my answer is here for another thread.

Also, I've added another answer here which is related to JASYP encryption which is unrelated to this question but just a reference to the same context. Feel free to skip. And hope these findings help and save some time.

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