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fix(android): file encryption

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This commit is contained in:
Hugo Pointcheval 2023-04-05 15:16:45 +02:00
parent 108c394a25
commit 0bf72447a0
Signed by: hugo
GPG Key ID: 3AAC487E131E00BC
3 changed files with 46 additions and 42 deletions
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2
packages/native_crypto_android/android/src/main/kotlin/fr/pointcheval/native_crypto_android/NativeCrypto.kt
View File

@ -111,7 +111,7 @@ class NativeCrypto(private val context: Context) : NativeCryptoAPI {
): Boolean {
// For now, only AES is supported
val aes = AES()
val params = FileParameters(context, plainTextPath, cipherTextPath)
val params = FileParameters(context, cipherTextPath, plainTextPath)
return aes.decryptFile(params, key)
}

79
packages/native_crypto_android/android/src/main/kotlin/fr/pointcheval/native_crypto_android/ciphers/AES.kt
View File

@ -2,6 +2,9 @@ package fr.pointcheval.native_crypto_android.ciphers
import fr.pointcheval.native_crypto_android.interfaces.Cipher
import fr.pointcheval.native_crypto_android.utils.FileParameters
import java.io.BufferedInputStream
import java.io.BufferedOutputStream
import javax.crypto.CipherInputStream
import javax.crypto.CipherOutputStream
import javax.crypto.spec.GCMParameterSpec
import javax.crypto.spec.SecretKeySpec
@ -60,28 +63,32 @@ class AES : Cipher {
cipherInstance!!.init(javax.crypto.Cipher.ENCRYPT_MODE, sk)
}
var len: Int?
val buffer = ByteArray(8192)
val inputFile = fileParameters.getFileInputStream()
val outputFile = fileParameters.getFileOutputStream()
val iv: ByteArray? = cipherInstance!!.iv
val input = BufferedInputStream(fileParameters.getFileInputStream())
outputFile?.write(iv)
outputFile?.flush()
var outputBuffered = BufferedOutputStream(fileParameters.getFileOutputStream(false))
val iv: ByteArray = cipherInstance!!.iv
// Prepend the IV to the cipherText file
outputBuffered.write(iv)
outputBuffered.flush()
outputBuffered.close()
// Reopen the file and append the cipherText
outputBuffered = BufferedOutputStream(fileParameters.getFileOutputStream(true))
val output = CipherOutputStream(outputBuffered, cipherInstance)
var i: Int
do {
i = input.read()
if (i != -1) output.write(i)
} while (i != -1)
output.flush()
output.close()
input.close()
outputBuffered.close()
val encryptedStream = CipherOutputStream(outputFile!!, cipherInstance)
while(true) {
len = inputFile?.read(buffer)
if (len != null && len > 0) {
encryptedStream.write(buffer,0,len)
} else {
break
}
}
encryptedStream.flush()
encryptedStream.close()
inputFile?.close()
outputFile.close()
return fileParameters.outputExists()
}
@ -110,9 +117,7 @@ class AES : Cipher {
val inputFile = fileParameters.getFileInputStream() ?: throw Exception("Error while reading IV")
// Read the first 12 bytes from the file
for (i in 0 until 12) {
iv[i] = inputFile.read().toByte()
}
inputFile.read(iv)
// Initialize secret key spec
val sk = SecretKeySpec(key, "AES")
@ -125,21 +130,19 @@ class AES : Cipher {
cipherInstance!!.init(javax.crypto.Cipher.DECRYPT_MODE, sk, gcmParameterSpec)
var len: Int?
val buffer = ByteArray(8192)
val outputFile = fileParameters.getFileOutputStream()
val decryptedStream = CipherOutputStream(outputFile!!, cipherInstance)
while (true) {
len = inputFile.read(buffer)
if(len > 0){
decryptedStream.write(buffer,0, len)
} else {
break
}
}
decryptedStream.flush()
decryptedStream.close()
inputFile.close()
val input = CipherInputStream(BufferedInputStream(inputFile), cipherInstance)
val output = BufferedOutputStream(fileParameters.getFileOutputStream(false))
var i: Int
do {
i = input.read()
if (i != -1) output.write(i)
} while (i != -1)
output.flush()
output.close()
input.close()
return fileParameters.outputExists()
}

7
packages/native_crypto_android/android/src/main/kotlin/fr/pointcheval/native_crypto_android/utils/FileParameters.kt
View File

@ -43,14 +43,15 @@ class FileParameters(ctx: Context, input: String, output: String) {
}
}
fun getFileOutputStream(): OutputStream? {
fun getFileOutputStream(append: Boolean): OutputStream? {
val path = outputPath
return try{
FileOutputStream(path)
FileOutputStream(path, append)
} catch(e: IOException){
val documentFile: DocumentFile = this.getDocumentFileByPath(path)
val documentUri = documentFile.uri
context.contentResolver.openOutputStream(documentUri)
val mode = if(append) "wa" else "w"
context.contentResolver.openOutputStream(documentUri, mode)
}
}