Encrypted text using AES/ECB/PCKS7Padding diffs from java

[gushengyuan]

When use AES/ECB/PCKS7Padding to encrypt text, the result is defferent form aes-js and java.

Here is the js code using aes-js: `// Convert text to bytes var text = 'this is a string will be AES_Encrypt'; var textBytes = aesjs.utils.utf8.toBytes(text); var padded = aesjs.padding.pkcs7.pad(textBytes);

// An example 128-bit key var key = "UITN25LMUQC436IM"; var keyBytes = aesjs.utils.utf8.toBytes(key); var aesEcb = new aesjs.ModeOfOperation.ecb(keyBytes); var encryptedBytes = aesEcb.encrypt(padded);

// To print or store the binary data, you may convert it to hex var encryptedHex = aesjs.utils.hex.fromBytes(encryptedBytes); console.log(encryptedHex);

// When ready to decrypt the hex string, convert it back to bytes var encryptedBytes = aesjs.utils.hex.toBytes(encryptedHex); var encryptedText = aesjs.utils.utf8.fromBytes(encryptedBytes);

var base = new Base64();
var encryptedBase64 = base.encode(encryptedText); //should be: fhTD0NNIzv4jUEhJuC1htFFXJ/4S/rL6tDCJPiNvJ8mVLHWOD0HWweuxHynxoZf9

// Since electronic codebook does not store state, we can // reuse the same instance. //var aesEcb = new aesjs.ModeOfOperation.ecb(key); var decryptedBytes = aesEcb.decrypt(encryptedBytes);

// Convert our bytes back into text var decryptedText = aesjs.utils.utf8.fromBytes(decryptedBytes); console.log(decryptedText); // "this is a string will be AES_Encrypt"

function Base64() {

// private property
_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

// public method for encoding
this.encode = function (input) {
	var output = "";
	var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
	var i = 0;
	input = _utf8_encode(input);
	while (i < input.length) {
		chr1 = input.charCodeAt(i++);
		chr2 = input.charCodeAt(i++);
		chr3 = input.charCodeAt(i++);
		enc1 = chr1 >> 2;
		enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
		enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
		enc4 = chr3 & 63;
		if (isNaN(chr2)) {
			enc3 = enc4 = 64;
		} else if (isNaN(chr3)) {
			enc4 = 64;
		}
		output = output +
		_keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
		_keyStr.charAt(enc3) + _keyStr.charAt(enc4);
	}
	return output;
}

// public method for decoding
this.decode = function (input) {
	var output = "";
	var chr1, chr2, chr3;
	var enc1, enc2, enc3, enc4;
	var i = 0;
	input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
	while (i < input.length) {
		enc1 = _keyStr.indexOf(input.charAt(i++));
		enc2 = _keyStr.indexOf(input.charAt(i++));
		enc3 = _keyStr.indexOf(input.charAt(i++));
		enc4 = _keyStr.indexOf(input.charAt(i++));
		chr1 = (enc1 << 2) | (enc2 >> 4);
		chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		chr3 = ((enc3 & 3) << 6) | enc4;
		output = output + String.fromCharCode(chr1);
		if (enc3 != 64) {
			output = output + String.fromCharCode(chr2);
		}
		if (enc4 != 64) {
			output = output + String.fromCharCode(chr3);
		}
	}
	output = _utf8_decode(output);
	return output;
}

// private method for UTF-8 encoding
_utf8_encode = function (string) {
	string = string.replace(/\r\n/g,"\n");
	var utftext = "";
	for (var n = 0; n < string.length; n++) {
		var c = string.charCodeAt(n);
		if (c < 128) {
			utftext += String.fromCharCode(c);
		} else if((c > 127) && (c < 2048)) {
			utftext += String.fromCharCode((c >> 6) | 192);
			utftext += String.fromCharCode((c & 63) | 128);
		} else {
			utftext += String.fromCharCode((c >> 12) | 224);
			utftext += String.fromCharCode(((c >> 6) & 63) | 128);
			utftext += String.fromCharCode((c & 63) | 128);
		}

	}
	return utftext;
}

// private method for UTF-8 decoding
_utf8_decode = function (utftext) {
	var string = "";
	var i = 0;
	var c = c1 = c2 = 0;
	while ( i < utftext.length ) {
		c = utftext.charCodeAt(i);
		if (c < 128) {
			string += String.fromCharCode(c);
			i++;
		} else if((c > 191) && (c < 224)) {
			c2 = utftext.charCodeAt(i+1);
			string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
			i += 2;
		} else {
			c2 = utftext.charCodeAt(i+1);
			c3 = utftext.charCodeAt(i+2);
			string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
			i += 3;
		}
	}
	return string;
}

}`

Here is the java code: `import java.security.Key; import java.security.Security;

import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; import org.bouncycastle.jce.provider.BouncyCastleProvider;

import org.apache.commons.codec.binary.Base64;

public class TestAes {

private static final String AESTYPE ="AES/ECB/PKCS7Padding";

public static String AES_Encrypt(String keyStr, String plainText) { 
    byte[] encrypt = null; 
    try{ 
        Key key = generateKey(keyStr);
        Cipher cipher = Cipher.getInstance(AESTYPE, "BC"); 
        cipher.init(Cipher.ENCRYPT_MODE, key); 
        encrypt = cipher.doFinal(plainText.getBytes());
    }catch(Exception e){ 
        e.printStackTrace(); 
    }

    return new String(Base64.encodeBase64(encrypt)); 
}

public static String AES_Decrypt(String keyStr, String encryptData) {
    byte[] decrypt = null; 
    try{ 
        Key key = generateKey(keyStr); 
        Cipher cipher = Cipher.getInstance(AESTYPE, "BC"); 
        cipher.init(Cipher.DECRYPT_MODE, key); 
        decrypt = cipher.doFinal(Base64.decodeBase64(encryptData)); 
    }catch(Exception e){ 
        e.printStackTrace(); 
    } 
    return new String(decrypt).trim(); 
} 

private static Key generateKey(String key)throws Exception{ 
    try{            
        SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES"); 
        return keySpec; 
    }catch(Exception e){ 
        e.printStackTrace(); 
        throw e; 
    } 

} 

public static void main(String[] args) { 
	Security.addProvider(new BouncyCastleProvider());
    String keyStr = "UITN25LMUQC436IM";  

    String plainText = "this is a string will be AES_Encrypt";
     
    String encText = AES_Encrypt(keyStr, plainText);
    String decString = AES_Decrypt(keyStr, encText); 
     
    System.out.println(encText); 
    System.out.println(decString); 

} 

}`

[RokerHRO]

Where do you do the PKCS#7 padding in your Java example?

[Ruffio]

@gushengyuan can this issue be closed? You havn't responded on @RokerHRO's question for more than a month...