在java中使用AES/CBC/PKCS5Padding加密后的文件大小是多少
[英]What is the file size after encryption using AES/CBC/PKCS5Padding in java
问题描述
I tried to use encryption and decryption when sending files using socket.
我在使用套接字发送文件时尝试使用加密和解密。 I use the AES/CBC/PKCS5Padding algorithm and first write the IV and then the file to the stream.我使用AES/CBC/PKCS5Padding算法并首先写入IV ，然后将文件写入流。
The problem is that the loop does not end when the file is receiving.问题是接收文件时循环没有结束。
I think this is due to the file size and the encrypted file seems to be smaller than the original file, While I give the size of the original file to the receiver.我认为这是由于文件大小和加密文件似乎比原始文件小，而我将原始文件的大小提供给接收者。 If this hypothesis is correct, is there a way to calculate the size of the encrypted file?如果这个假设是正确的，有没有办法计算加密文件的大小？
File sender文件发件人
SecretKey keySpec = new SecretKeySpec(key, "AES");
byte[] iv = AES.randomNonce(16);
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
outputStream = socket.getOutputStream();
outputStream.write(iv);
outputStream.flush();
inputStream = context.getContentResolver().openInputStream(message.getUri());
cipherOutputStream = new CipherOutputStream(outputStream, cipher);
long size = message.getSize();
long written = 0;
byte[] buffer = new byte[8192];
int count;
int percent = 0;
while (!isStopped && (count = inputStream.read(buffer)) > 0) {
cipherOutputStream.write(buffer, 0, count);
written += count;
int p = (int) (((float) written / (float) size) * 100);
if (percent != p) {
percent = p;
if (onProgressListener != null) {
onProgressListener.onProgress(percent);
}
}
}
cipherOutputStream.flush();
if (onProgressListener != null) {
onProgressListener.onEnd(null);
}
File receiver文件接收器
inputStream = socket.getInputStream();
fileOutputStream = new FileOutputStream(file);
byte[] iv = new byte[16];
inputStream.read(iv);
SecretKey keySpec = new SecretKeySpec(key, "AES");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivParameterSpec);
cipherInputStream = new CipherInputStream(inputStream, cipher);
long size = message.getSize();
long read = size;
byte[] buffer = new byte[8192];
int count;
int percent = 0;
while (!isStopped && read > 0 && (count = cipherInputStream.read(buffer, 0, (int) Math.min(buffer.length, read))) != -1) {
fileOutputStream.write(buffer, 0, count);
read -= count;
int p = (int) (((float) read / (float) size) * 100);
if (percent != p) {
percent = p;
if (onProgressListener != null) {
onProgressListener.onProgress(100 - percent);
}
}
}
if (onProgressListener != null) {
onProgressListener.onEnd(Uri.fromFile(file));
}
3 个解决方案
解决方案1
4 2020-11-14 19:59:35
I tried to use encryption and decryption when sending files using socket.使用套接字发送文件时，我尝试使用加密和解密。 I use the AES/CBC/PKCS5Padding algorithm and first write the IV and then the file to the stream.我使用AES/CBC/PKCS5Padding算法，首先将IV写入文件，然后将文件写入流。
The problem is that the loop does not end when the file is receiving.问题在于，接收文件时循环不会结束。
I think this is due to the file size and the encrypted file seems to be smaller than the original file, While I give the size of the original file to the receiver.我认为这是由于文件大小，加密的文件似乎比原始文件小，而我将原始文件的大小提供给接收器。 If this hypothesis is correct, is there a way to calculate the size of the encrypted file?如果此假设正确，是否可以计算加密文件的大小？
File sender文件发件人
SecretKey keySpec = new SecretKeySpec(key, "AES");
byte[] iv = AES.randomNonce(16);
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
outputStream = socket.getOutputStream();
outputStream.write(iv);
outputStream.flush();
inputStream = context.getContentResolver().openInputStream(message.getUri());
cipherOutputStream = new CipherOutputStream(outputStream, cipher);
long size = message.getSize();
long written = 0;
byte[] buffer = new byte[8192];
int count;
int percent = 0;
while (!isStopped && (count = inputStream.read(buffer)) > 0) {
cipherOutputStream.write(buffer, 0, count);
written += count;
int p = (int) (((float) written / (float) size) * 100);
if (percent != p) {
percent = p;
if (onProgressListener != null) {
onProgressListener.onProgress(percent);
}
}
}
cipherOutputStream.flush();
if (onProgressListener != null) {
onProgressListener.onEnd(null);
}
File receiver文件接收器
inputStream = socket.getInputStream();
fileOutputStream = new FileOutputStream(file);
byte[] iv = new byte[16];
inputStream.read(iv);
SecretKey keySpec = new SecretKeySpec(key, "AES");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivParameterSpec);
cipherInputStream = new CipherInputStream(inputStream, cipher);
long size = message.getSize();
long read = size;
byte[] buffer = new byte[8192];
int count;
int percent = 0;
while (!isStopped && read > 0 && (count = cipherInputStream.read(buffer, 0, (int) Math.min(buffer.length, read))) != -1) {
fileOutputStream.write(buffer, 0, count);
read -= count;
int p = (int) (((float) read / (float) size) * 100);
if (percent != p) {
percent = p;
if (onProgressListener != null) {
onProgressListener.onProgress(100 - percent);
}
}
}
if (onProgressListener != null) {
onProgressListener.onEnd(Uri.fromFile(file));
}
解决方案2
2
I tried to use encryption and decryption when sending files using socket.使用套接字发送文件时，我尝试使用加密和解密。 I use the AES/CBC/PKCS5Padding algorithm and first write the IV and then the file to the stream.我使用AES/CBC/PKCS5Padding算法，首先将IV写入文件，然后将文件写入流。
The problem is that the loop does not end when the file is receiving.问题在于，接收文件时循环不会结束。
I think this is due to the file size and the encrypted file seems to be smaller than the original file, While I give the size of the original file to the receiver.我认为这是由于文件大小，加密的文件似乎比原始文件小，而我将原始文件的大小提供给接收器。 If this hypothesis is correct, is there a way to calculate the size of the encrypted file?如果此假设正确，是否可以计算加密文件的大小？
File sender文件发件人
SecretKey keySpec = new SecretKeySpec(key, "AES");
byte[] iv = AES.randomNonce(16);
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, keySpec, ivParameterSpec);
outputStream = socket.getOutputStream();
outputStream.write(iv);
outputStream.flush();
inputStream = context.getContentResolver().openInputStream(message.getUri());
cipherOutputStream = new CipherOutputStream(outputStream, cipher);
long size = message.getSize();
long written = 0;
byte[] buffer = new byte[8192];
int count;
int percent = 0;
while (!isStopped && (count = inputStream.read(buffer)) > 0) {
cipherOutputStream.write(buffer, 0, count);
written += count;
int p = (int) (((float) written / (float) size) * 100);
if (percent != p) {
percent = p;
if (onProgressListener != null) {
onProgressListener.onProgress(percent);
}
}
}
cipherOutputStream.flush();
if (onProgressListener != null) {
onProgressListener.onEnd(null);
}
File receiver文件接收器
inputStream = socket.getInputStream();
fileOutputStream = new FileOutputStream(file);
byte[] iv = new byte[16];
inputStream.read(iv);
SecretKey keySpec = new SecretKeySpec(key, "AES");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivParameterSpec);
cipherInputStream = new CipherInputStream(inputStream, cipher);
long size = message.getSize();
long read = size;
byte[] buffer = new byte[8192];
int count;
int percent = 0;
while (!isStopped && read > 0 && (count = cipherInputStream.read(buffer, 0, (int) Math.min(buffer.length, read))) != -1) {
fileOutputStream.write(buffer, 0, count);
read -= count;
int p = (int) (((float) read / (float) size) * 100);
if (percent != p) {
percent = p;
if (onProgressListener != null) {
onProgressListener.onProgress(100 - percent);
}
}
}
if (onProgressListener != null) {
onProgressListener.onEnd(Uri.fromFile(file));
}
解决方案3
1 2021-10-18 14:22:32
Check for this exception.检查此异常。 java.io.IOException: javax.crypto.BadPaddingException java.io.IOException: javax.crypto.BadPaddingException
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