aes | 易学教程

AES128 in CBC mode implementation using Crypto++ library

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问题 In the input file I have: on the first line a key which is encoded in hex and with length of 16 bytes; on the second line encrypted message ( AES128 in CBC mode , with a random iv prepended to the encrypted message). This is how I tried to decrypt: #include<iostream> using namespace std; #include <fstream> #include <string.h> #include <cryptopp/aes.h> #include <cryptopp/modes.h> #include <cryptopp/filters.h> using namespace CryptoPP; int main(void) { ifstream in("input0.txt"); ofstream out(

AES encryption versus decryption speed

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问题 I had read somewhere the decryption can be performed faster than encryption. Is this correct? This would be a pure software implementation using may be openssl. 回答1: The block cipher mode of operation might have a direct impact in the performance of the encryption/decryption processes. Roughly speaking; the operations performed on each round while AES is encrypting a block of data are performed in the opposite direction (decryption), so no reasonable justification for performance variation in

AES 128 GCM objective C osx

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问题 I am trying to encrypt/decrypt a string in an AES-128 GCM format in objective c. I have looked everywhere but can't seem to find a working solution. 回答1: Not so long ago I had a similar problem and the best answer I could find was this one. To sum up, iOS has some functions to do what you want but they are private. So, until Apple decides to release these functions, I opted for developing my own library, currently stored in GitHub and available in CocoaPods. The case you describe could be

PHP - Class declarations may not be nested

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问题 I have a project in cakephp, when I call a vendor for decrypting a string using AES, I get the error: Fatal error: Class declarations may not be nested in /var/www/html/myproject/cake/libs/log/file_log.php on line 30 This is the code in my controller: App::import('vendor', 'aes', array('file' => 'AES/AES.php')); $aes = new AesCtr(); $decrypted = $aes->decrypt($encrypted, "mykey", 128); And this is part of the vendor (one single file called AES.php): class Aes { //....Methods } class AesCtr

ggplot2——坐标系篇（转载）

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目录：初始图样如何修改坐标轴的显示范围如何修改坐标轴的标签（内容、大小、字体、颜色、加粗、位置、角度）如何修改坐标轴的刻度标签（内容）如何修改坐标轴的刻度标签（大小、字体、颜色、加粗、位置、角度）如何修改坐标轴的刻度间隔如何去掉网格线如何去掉刻度标签如何去掉刻度线如何去掉外层边框如何再加上X轴、Y轴（无刻度、无标签）（更多内容请见： R、ggplot2、shiny 汇总）初始图样： library (ggplot2) dt = data .frame ( A = 1:10, B = c (2,15,6,18,9,7,13,15,10,3) , C = c (' A ',' C ',' A ',' B ',' C ',' D ',' A ',' C ',' D ',' B ') ) p = ggplot(dt, aes(x = A , y = B , color = C , group = factor( 1 ))) + geom_point(size = 3.8 ) + geom_line(size = 0.8 ) + geom_text(aes(label = B , vjust = 1.1 , hjust = - 0.5 , angle = 45 ), show_guide = FALSE ) ## 添加点的数值 p 1 2 3 4 5 6 7 8

Cipher: What is the reason for IllegalBlockSizeException?

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问题 I have observed the following when I worked with Cipher. Encryption code: Cipher aes = Cipher.getInstance("AES"); aes.init(Cipher.ENCRYPT_MODE, generateKey()); byte[] ciphertext = aes.doFinal(rawPassword.getBytes()); Decryption code : Cipher aes = Cipher.getInstance("AES"); aes.init(Cipher.DECRYPT_MODE, generateKey()); byte[] ciphertext = aes.doFinal(rawPassword.getBytes()); I get IllegalBlockSizeException ( Input length must be multiple of 16 when ...) on running the Decrypt code. But If I

TPLockBox3 and PHP - AES Encrypt in Delphi, Decrypt in PHP

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问题 I have a trouble with lockbox3 and PHP mcrypt. I can't pass IV to PHP. Delphi code: var Codec: TCodec; CL: TCryptographicLibrary; PlainStream: TStringStream; CipherStream: TMemoryStream; begin PlainStream := TStringStream.Create(Edit1.Text); CipherStream := TMemoryStream.Create; CL := TCryptographicLibrary.Create(nil); Codec := TCodec.Create(nil); Codec.CryptoLibrary := CL; Codec.ChainModeId := uTPLb_Constants.CBC_ProgId; Codec.StreamCipherId := uTPLb_Constants.BlockCipher_ProgId; Codec

Implementing AES-256 with 1024 byte key

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问题 I am trying to write Java code which will do AES-256 encryption/decryption using 1024 byte key. I looked into Internet for the implementation and there are many way to implement. I took a look at the following tutorials: http://karanbalkar.com/2014/02/tutorial-76-implement-aes-256-encryptiondecryption-using-java/ https://gist.github.com/bricef/2436364 but didn't find what steps are the required. So my question is What I need to to start encryptiopn/decryption. Isn't specifying algorithm (AES

Unable to Decrypt a text containg + symbol using AES 256bit Decryption:javax.crypto.BadPaddingException: Given final block not properly padded

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问题 Hi I am not able to decrypt a text containing '+' symbol inside the JSP page , I get the following error javax.crypto.BadPaddingException: Given final block not properly padded. However the code works fine if I run from Eclipse or if I convert the code into Executable Jar. JARS used : local_policy.jar US_export_policy.jar Below is my Java code import java.security.Key; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; import sun.misc.BASE64Decoder; import sun.misc

Initialization Vector (IV) in CBC mode for AES [duplicate]

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问题 This question already has answers here : Good AES Initialization Vector practice (8 answers) Closed 3 years ago . I understand the IV should be random and XORed with the plain text to start the encryption. My question is, in addition to the key, do I have to remember the random IV as well for decryption? 回答1: The IV needs to be random, but does not need to be secret. Usual practice is to prepend the IV to the cyphertext before transmitting it. When decrypting, use the first 16 bytes of the