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  • Compute the AES-encryption key given the plaintext and its ciphertext?

    - by Null Pointers etc.
    I'm tasked with creating database tables in Oracle which contain encrypted strings (i.e., the columns are RAW). The strings are encrypted by the application (using AES, 128-bit key) and stored in Oracle, then later retrieved from Oracle and decrypted (i.e., Oracle itself never sees the unencrypted strings). I've come across this one column that will be one of two strings. I'm worried that someone will notice and presumably figure out what those two values to figure out the AES key. For example, if someone sees that the column is either Ciphertext #1 or #2: Ciphertext #1: BF,4F,8B,FE, 60,D8,33,56, 1B,F2,35,72, 49,20,DE,C6. Ciphertext #2: BC,E8,54,BD, F4,B3,36,3B, DD,70,76,45, 29,28,50,07. and knows the corresponding Plaintexts: Plaintext #1 ("Detroit"): 44,00,65,00, 74,00,72,00, 6F,00,69,00, 74,00,00,00. Plaintext #2 ("Chicago"): 43,00,68,00, 69,00,63,00, 61,00,67,00, 6F,00,00,00. can he deduce that the encryption key is "Buffalo"? 42,00,75,00, 66,00,66,00, 61,00,6C,00, 6F,00,00,00. I'm thinking that there should be only one 128-bit key that could convert Plaintext #1 to Ciphertext #1. Does this mean I should go to a 192-bit or 256-bit key instead, or find some other solution? (As an aside, here are two other ciphertexts for the same plaintexts but with a different key.) Ciphertext #1 A ("Detroit"): E4,28,29,E3, 6E,C2,64,FA, A1,F4,F4,96, FC,18,4A,C5. Ciphertext #2 A ("Chicago"): EA,87,30,F0, AC,44,5D,ED, FD,EB,A8,79, 83,59,53,B7.

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  • Repairing hard disk when Windows installation disk won't boot

    - by Echows
    I'm trying to recover some data from a faulty hard disk with Windows installed on it (on which Windows won't even boot). I have tried so far: Booting to Ubuntu live USB stick and running ntfsfix (didn't work) Trying to mount the broken partition when running Ubuntu from usb stick (doesn't mount) Running photorec image recovery tool from live Ubuntu (it found some stuff but not the images I was looking for) Now as a last resort I got myself a Windows installation on a USB stick so that I can try fdisk, but the installer doesn't work. The loading screen shows up and then the installer crashes. The installer works fine on other computers. I suspect that the installer is trying to read the hard drive to see if there's something there but when it can't read one partition, it crashes. On Ubuntu, I can mount other partitions except the one I'm interested in so at least the hard drive is not completely dead. So the question is, what options do I have left? To be more specific, my goal is to recover some images from the faulty ntfs-partition on the hard drive. Other than that, I don't care about the contents of the hard disk.

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  • iphone encryption not working

    - by Futur
    I have this encryption/decryption implemented and executes with no error, but i am unable to decrypt the data and im not sure whether the data is encrypted, kindly help. - (NSData *)AES256EncryptWithKey:(NSString *)key { char keyPtr[kCCKeySizeAES256+1]; bzero(keyPtr, sizeof(keyPtr)); [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [strData length]; data = [[NSData alloc] init]; data = [strData dataUsingEncoding:NSUTF8StringEncoding]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void *pribuffer = malloc(bufferSize); size_t numBytesEncrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, keyPtr, kCCKeySizeAES256, NULL /* initialization vector (optional) */, [data bytes], dataLength, /* input */ [data bytes], bufferSize, /* output */ &numBytesEncrypted); if (cryptStatus == kCCSuccess) { return [NSData dataWithBytesNoCopy:data length:numBytesEncrypted]; }} The decryption is : -(NSData *)AES256DecryptWithKey:(NSString *)key andForData:(NSData *)objDataObject { char keyPtr[kCCKeySizeAES256+1]; bzero(keyPtr, sizeof(keyPtr)); [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [objDataObject length]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void *buffer = malloc(bufferSize); size_t numBytesDecrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, keyPtr, kCCKeySizeAES256, NULL, [objDataObject bytes], dataLength, [objDataObject bytes], bufferSize, &numBytesDecrypted); if (cryptStatus == kCCSuccess) { return [NSData dataWithBytesNoCopy:objDataObject length:numBytesDecrypted]; } } i call the above methods like this: CryptoClass *obj = [CryptoClass new]; NSData *objData = [obj AES256EncryptWithKey:@"hell"]; NSData *val = [obj AES256DecryptWithKey:@"hell" andForData:objData ]; NSLog(@"decrypted string is : %@ AND LENGTH IS %d",[val description],[val length]); Decryption doesnt seem to happen at all and the encryption - i am not sure about it, kindly help me here.

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  • iPhone --- 3DES Encryption returns "wrong" results?

    - by Jan Gressmann
    Hello fellow developers, I have some serious trouble with a CommonCrypto function. There are two existing applications for BlackBerry and Windows Mobile, both use Triple-DES encryption with ECB mode for data exchange. On either the encrypted results are the same. Now I want to implent the 3DES encryption into our iPhone application, so I went straight for CommonCrypto: http://www.opensource.apple.com/source/CommonCrypto/CommonCrypto-32207/CommonCrypto/CommonCryptor.h I get some results if I use CBC mode, but they do not correspond with the results of Java or C#. Anyway, I want to use ECB mode, but I don't get this working at all - there is a parameter error showing up... This is my call for the ECB mode... I stripped it a little bit: const void *vplainText; plainTextBufferSize = [@"Hello World!" length]; bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1); plainText = (const void *) [@"Hello World!" UTF8String]; NSString *key = @"abcdeabcdeabcdeabcdeabcd"; ccStatus = CCCrypt(kCCEncrypt, kCCAlgorithm3DES, kCCOptionECBMode, key, kCCKeySize3DES, nil, // iv, not used with ECB plainText, plainTextBufferSize, (void *)bufferPtr, // output bufferPtrSize, &movedBytes); t is more or less the code from here: http://discussions.apple.com/thread.jspa?messageID=9017515 But as already mentioned, I get a parameter error each time... When I use kCCOptionPKCS7Padding instead of kCCOptionECBMode and set the same initialization vector in C# and my iPhone code, the iPhone gives me different results. Is there a mistake by getting my output from the bufferPtr? Currently I get the encrypted stuff this way: NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes]; result = [[NSString alloc] initWithData:myData encoding:NSISOLatin1StringEncoding]; It seems I almost tried every setting twice, different encodings and so on... where is my error?

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  • Server 2008 Disk Management Hangs

    - by Payson Welch
    So I have looked everywhere for the solution to this and have tried many things. There is one post on SE related to this and I tried the suggested answer but I am still having problems. We have a server running Server 2008 R2 Standard x64. I need to increase the space of C: since the free space is running very low. However when I open Server Manager and try to go to the "Disk Management" snap-in it just hangs. There is a status message on the bottom of the window that says "Connecting to Virtual Disk Service...". Here are the steps I have taken: Ran sfc /scannow Set all of the drives to be dirty and rebooted so that they would be scanned Executed chkdsk /f /r /b /v on all of the drives. Checked for Windows updates (none). Verified that the services "Virtual Disk", "RPC Procedures" and "Plug and Play" are all running. One symptom is that the service "Virtual Disk" does not cleanly shut down. I receive a message about the process being unexpectedly terminated when I try to stop or restart it. Also I cannot find anything relevant in the event logs. Any ideas or suggestions?

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  • Variable size encrypted container

    - by Cray
    Is there an application similar to TrueCrypt, but the one that can make variable size containers opposed to fixed-size or only-growing-to-certain-amount containers which can be made by TrueCrypt? I want this container to be able to be mounted to a drive/folder, and the size of the outer container not be much different from the total size of all the files that I put into the mounted folder, while still providing strong encryption. If to put it in other words, I want a program like truecrypt, which not only automatically grows the container if I put in new files, but also decreases it's size if some files are deleted. I know there are some issues of course, and it would not work 100% as truecrypt, because it basically works on the sector level of the disk, giving all the filesystem-control to the OS, and so when I remove a file, it might as well be left there, or there might be some fragmentation issues that would stop just truncating the volume from working, but perhaps a program can be built in some other way? Instead of providing sector-level interface, it would provide filesystem-level interface? A filesystem inside a file which would support shrinking when files are deleted?

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  • Best solution top keep data secure

    - by mrwooster
    What is the simplest and most elegant way of storing a small amount of data in a reasonably secure way? I am not looking for ridiculous levels of advanced encryption (AES-256 is more than enough) and I am only looking to encrypt a small number of files. The files I wish to encrypt are mostly comprised of password lists and SSH keys for servers. Unfortunately it is impossible to keep track of ever changing passwords for my servers (and SSH keys) and so need to keep a list of the passwords. Obviously this list needs to be secure, and also portable (I work from multiple locations). At the moment, I use a 10MB encrypted disk image on my mac (std .dmg AES-256) and just mount it whenever I need access to the data. To my knowledge this is very secure and I am very happy using it. However, the data is not very portable. I would like to be able to access my data from other machines (especially ones running linux), and I am aware that there are quite a few issues trying to mount an encrypted .dmg on linux. An alternative I have considered is to create a tar archive containing the files and use gpg --symmetric to encrypt it, but this is not a very elegant solution as it requires gpg to be installed on every system. So, what over solutions exist, and which ones would you consider to be the most elegant? Ty

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  • My system is always disk-bound (the disk light is always on). Why is this?

    - by Scoobie
    I have been given a laptop by the good folks at my company on which to do my work (Java development). I usually use eclipse as my primary development platform. The laptop is a Dell D830 and runs Windows 7 - 32 bit. Although the processor supports a 64 bit instruction-set, licensing limits me to running the 32 bit OS. The HDD is a WD1600BEVT (Western Digital). I have noticed that my disk is always very slow. Windows start up is usually pretty quick, however as soon as I log on, my disk light stays on and usually, the laptop takes about 4 minutes (after logging in -- immediately upon getting the prompt to press Ctrl + Alt + Del to log in) before it's usable. Questions: Is this expected behavior? What can I do to examine the disk and determine the cause of the problem? What can I do to improve my disk's performance? Any optimizations you may be able to suggest? Other Questions: Some have suggested running Process Monitor (from sysinternals), but how would i get the log since start up? Instead of trying to fix this myself, should I simply push this onto the system administrator? Thanks all.

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  • iPhone 3DES encryption key length issue

    - by Russell Hill
    Hi, I have been banging my head on a wall with this one. I need to code my iPhone application to encrypt a 4 digit "pin" using 3DES in ECB mode for transmission to a webservice which I believe is written in .NET. + (NSData *)TripleDESEncryptWithKey:(NSString *)key dataToEncrypt:(NSData*)encryptData { NSLog(@"kCCKeySize3DES=%d", kCCKeySize3DES); char keyBuffer[kCCKeySize3DES+1]; // room for terminator (unused) bzero( keyBuffer, sizeof(keyBuffer) ); // fill with zeroes (for padding) [key getCString: keyBuffer maxLength: sizeof(keyBuffer) encoding: NSUTF8StringEncoding]; // encrypts in-place, since this is a mutable data object size_t numBytesEncrypted = 0; size_t returnLength = ([encryptData length] + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1); // NSMutableData* returnBuffer = [NSMutableData dataWithLength:returnLength]; char* returnBuffer = malloc(returnLength * sizeof(uint8_t) ); CCCryptorStatus ccStatus = CCCrypt(kCCEncrypt, kCCAlgorithm3DES , kCCOptionECBMode, keyBuffer, kCCKeySize3DES, nil, [encryptData bytes], [encryptData length], returnBuffer, returnLength, &numBytesEncrypted); if (ccStatus == kCCParamError) NSLog(@"PARAM ERROR"); else if (ccStatus == kCCBufferTooSmall) NSLog(@"BUFFER TOO SMALL"); else if (ccStatus == kCCMemoryFailure) NSLog(@"MEMORY FAILURE"); else if (ccStatus == kCCAlignmentError) NSLog(@"ALIGNMENT"); else if (ccStatus == kCCDecodeError) NSLog(@"DECODE ERROR"); else if (ccStatus == kCCUnimplemented) NSLog(@"UNIMPLEMENTED"); if(ccStatus == kCCSuccess) { NSLog(@"TripleDESEncryptWithKey encrypted: %@", [NSData dataWithBytes:returnBuffer length:numBytesEncrypted]); return [NSData dataWithBytes:returnBuffer length:numBytesEncrypted]; } else return nil; } } I do get a value encrypted using the above code, however it does not match the value from the .NET web service. I believe the issue is that the encryption key I have been supplied by the web service developers is 48 characters long. I see that the iPhone SDK constant "kCCKeySize3DES" is 24. So I SUSPECT, but don't know, that the commoncrypto API call is only using the first 24 characters of the supplied key. Is this correct? Is there ANY way I can get this to generate the correct encrypted pin? I have output the data bytes from the encryption PRIOR to base64 encoding it and have attempted to match this against those generated from the .NET code (with the help of a .NET developer who sent the byte array output to me). Neither the non-base64 encoded byte array nor the final base64 encoded strings match.

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  • Rijndael encryption from Action Script to C#

    - by Coppermill
    I am trying to share encryption between Action Script and C# My task is to decrypt the following message within C# f1ca22a365ba54c005c3eb599d84b19c354d26dcf475ab4be775b991ac97884791017b12471000def05bb77bfe9c3a97d44ef78c9449f12daf6e25b61ab1a281 It uses Rijndael encyption , ECB mode (electronic code book), Key: Pas5pr@se , 128 bit key size and block size. The problem I have is I can't seem to do it, anyone help me on this?

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  • Using Blowfish Encryption within .NET

    - by Cragly
    I am working on a project where I need to undertake Blowfish encryption and decryption. Is there anything out there that others are using to do this within but cannot find anything within a .NET C# environment? I would ideally like something does not rely on running an exe as this will eventually live on a live server where exe’s are bared! I have read some of the older posts on SO but nothing suitable. Any ideas? Thanks

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  • Win32 API P-Invoke to bring a disk online, offline, and set unique ID

    - by Andy Schneider
    I am currently using Diskpart to accomplish these functions, but i would like to be able to use P-Invoke and not have to shell out to an external process in my C# app. The example Diskpart scripts are: //Online a disk Select disk 7 disk online // Reset GPT Identifier select disk 7 UNIQUEID DISK ID=baf784e7-6bbd-4cfb-aaac-e86c96e166ee I tried searching pinvoke.net but could only find functions that dealt with volumes, not disks. Any idea on how to accomplish these diskpart commands using Pinvoke?

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  • Auto Encryption of web.config connection string

    - by Klaas Jan
    I want to encrypt the connection string in web.config, the problem is each time a developer changes the connection string in web.config and publishes, it needs to be encrypted every time in the web server. Is there any way that the connection string can encrypted automatically every time someone publishes it? Note :- All of us work on our local machines other than the server. So encryption using local machine key is not an option.

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  • Quantum Computing and Encryption Breaking

    - by Earlz
    Ok, I read a while back that Quantum Computers can break most types of hashing and encryption in use today in a very short amount of time(I believe it was mere minutes). How is it possible? I've tried reading articles about it but I get lost at the a quantum bit can be 1, 0, or something else. Can someone explain how this relates to cracking such algorithms in plain English without all the fancy maths?

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  • How to safely store encryption key in a .NET assembly

    - by Alex
    In order to prevent somebody from grabbing my data easily, I cache data from my service as encrypted files (copy protection, basically). However, in order to do this, I must store the encryption key within the .NET assembly so it is able to encrypt and decrypt these files. Being aware of tools like Red Gate's .NET Reflector which can pull my key right out, I get a feeling that this is not a very safe way of doing it... are there any best practices to doing this?

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  • Does mcrypt support asymmetric encryption?

    - by bryanagee
    I want to use asymmetric encryption of headers in RESTful requests to verify the identity of the system sending the request: i e System A encrypts it's name, timestamp, and the service name using it's public key in a request to System B. System B then uses the public key of System A to decrypt, proving the authenticity of the request. 1) Does php-mcrypt support this? 2) Has anyone benchmarked this type of operation?

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  • Public Private Key Encryption Tutorials

    - by Jake M
    Do you know of a tutorial that demonstrates Public Private Key encryption(PPKE) in C++ or C? I am trying to learn how it works and eventually use Crypto++ to create my own encryptions using public private keys. Maybe theres a Crypto++ PPKE tutorial? Maybe someone can explain the relationship(if any) between the public and private keys? Could anyone suggest some very simple public and private key values I could use(like 'char*32','char/32') to create my simple PPKE program to understand the concept?

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