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• JUJU and ERROR environment has no access-key or secret-key

  - by Riccardo Magrini

  following the official guide: [1]https://juju.ubuntu.com/docs/config-maas.html and considered that I've generated the ssh key (added it to UI of MAAS) and the API key, my environments.yaml file presents in this way: environments: maas: type: maas maas-server: 'http://x.x.x.x/MAAS/' maas-oauth: 'NDPA86PsEzS7bFynSy:vqJLkyHUJbvYzbtY5Q:sXXXXXXXXXXXXXXXXXXXXXX admin-secret: 'nothing' default-series: precise authorized-keys-path: ~/.ssh/id_rsa.pub # or any file you want. when I try to run the command: juju bootstrap receive the following error: ERROR environment has no access-key or secret-key Someone can explain me where is the wrong? MAAS and JUJU are installed using their ppa stable on an Ubuntu 12.04.3 Server

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• Free Mac whole disk encryption

  - by stevekuo

  Are there any free solutions for encrypting the entire boot disk on a Mac? I'm aware of PGP's Whole Disk Encryption, but it's a bit steep at $149. TrueCrypt's System Encryption seems to only work with Windows.

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• Best Secure Encryption for Zip Files via Linux

  - by Daniel

  I want to use highly secure encryption for zipped files via Linux/Ubuntu using a command line terminal, what is the best command line tool to get this job done? zip -e -P PASSWORD file1 file2 file3 file4 Or 7za a file.7z *.txt -pSECRET What encryption is used and how secure is it?

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• iPhone's Mail application and data encryption

  - by Maroloccio

  I use the iPhone Mail application to check my Gmail (IMAP). Is the data stored on the iPhone "secure"? Is it, for instance, encrypted? Key strength? Thanks! I searched the site for "iphone encryption" but could not find an answer re: encryption level (if any).

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• Foreign key reference to a two-column primary key

  - by Adam Ernst

  One of my tables has a two-column primary key: CREATE TABLE tournament ( state CHAR(2) NOT NULL, year INT NOT NULL, etc..., PRIMARY KEY(state, year) ); I want a reference to the tournament table from another table, but I want this reference to be nullable. Here's how I might do it, imagining that a winner doesn't necessarily have a tournament: CREATE TABLE winner ( name VARCHAR NOT NULL, state CHAR(2) NULL, year INT NULL ); If state is null but year is not, or vice-versa, the table would be inconsistent. I believe the following FOREIGN KEY constraint fixes it: ALTER TABLE winner ADD CONSTRAINT FOREIGN KEY fk (name, state) REFERENCES tournament (name, state); Is this the proper way of enforcing consistency? Is this schema properly normalized?

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• Primary Key Identity Value Increments On Unique Key Constraint Violation

  - by Jed

  I have a SqlServer 2008 table which has a Primary Key (IsIdentity=Yes) and three other fields that make up a Unique Key constraint. In addition I have a store procedure that inserts a record into the table and I call the sproc via C# using a SqlConnection object. The C# sproc call works fine, however I have noticed interesting results when the C# sproc call violates the Unique Key constraint.... When the sproc call violates the Unique Key constraint, a SqlException is thrown - which is no surprise and cool. However, I notice that the next record that is successfully added to the table has a PK value that is not exactly one more than the previous record - For example: Say the table has five records where the PK values are 1,2,3,4, and 5. The sproc attempts to insert a sixth record, but the Unique Key constraint is violated and, so, the sixth record is not inserted. Then the sproc attempts to insert another record and this time it is successful. - This new record is given a PK value of 7 instead of 6. Is this normal behavior? If so, can you give me a reason why this is so? (If a record fails to insert, why is the PK index incremented?) If this is not normal behavior, can you give me any hints as to why I am seeing these symptoms?

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• Encryption setup for Linux NAS?

  - by Daniel

  There's a bazillion hard disk encryption HOWTOs, but somehow I can't find one that actually does what I want. Which is: I have a home NAS running Ubuntu, which is being accessed by a Linux and a Win XP client. (Hopefully MacOS X soon...) I want to setup encryption for home dirs on the NAS so that: It does not interfere with the boot process (since the NAS it tucked away in a cupboard), the home dirs should be accessible as a regular file system on the client(s) (e.g. via SMB), it is easy to use by 'normal' people, (so it does not require SSH-ing to the NAS, mount the encrypted partition on command line, then connecting via SMB, and finally umount the partition after being done. I can't explain that to my mom, or in fact to anyone.) does not store the encryption key the NAS itself, encrypts file meta-data and content (i.e. safe against the 'RIAA' attack, where an intruder should not be able to identify which songs are in your MP3 collection). What I hoped to do was use Samba + PAM. The idea was that on connecting to the SMB server, I'd have to enter the password on the client, which sends it to the server for authentication, which would use the password to mount the encrpytion partition, and would unmount it again when the session was closed. Turns out that doesn't really work, because SMB does not transmit the password in the plain and hence I can't configure PAM to use the incoming password to mount the encrypted patition. So... anything I'm overlooking? Is there any way in which I can use the password entered on the client (e.g. on SMB connect) to initiate mounting the encrypted dir on the server?

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• The Other "C" in CRM

  - by Brian Dayton

  Folks who know me know that I rarely, if ever, talk politics. And I never talk politicians. Having grown up in a household with one parent leaning left and the other leaning to the right it was the best way to keep the peace. This isn't about politics. It's about "constituents" and the need to improve the services and service levels for people--at the city, county, state/province, etc. level all the way up to national governments. As a citizen and tax payer it's also important to me that these services be provided at a reasonable cost. If there's a better and more efficient way to do something then it's my hope that a public sector organization takes advantage of technology the same way private sector companies do. Social services organizations have a complex job. They provide the services that people need, from healthcare and children's assistance to helping people find jobs. But many of these organizations are still managing these processes manually or outdated, home-grown applications that could have been written up to 30 years ago. A lot has changed in technology. On the (this is as political as I'm going to get) political front, stakeholders like you and me are expecting greater transparency on where and how funds are spent. I'll admit that most of the time, when I think about CRM systems, I think about my experience as a customer of my bank, utilities company or cable operator. But now that I'm older, have children and a house--I find myself interacting more and more with agencies and services organizations. My experiences are sometimes good and sometimes not so good. Along those lines, last week's announcement of Siebel CRM 8.2 for Public Sector caught my eye. You may not work in the public sector, but you are a constituent of some--actually a lot--of public sector organizations. I don't know which CRM systems city and county utilize but I'm going to start paying closer attention.

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• Encrypt tar file asymmetrically

  - by DerMike

  I want to achieve something like tar -c directory | openssl foo > encrypted_tarfile.dat I need the openssl tool to use public key encryption. I found an earlier question about symmetric encryption at the command promt (sic!), which does not suffice. I did take a look in the openssl(1) man page and only found symmetric encryption. Does openssl really not support asymmetric encryption? Basically many users are supposed to create their encrypted tar files and store them in a central location, but only few are allowed to read them.

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• encryption decryption function in php

  - by parthav

  import gnupg, urllib retk = urllib.urlopen("http://keyserver.pramberger.at/pks/" "lookup?op=get&search=userid for the key is required") pub_key = retk.read() #print pub_key gpg = gnupg.GPG(gnupghome="/tmp/foldername", verbose=True) print "Import the Key :", gpg.import_keys(pub_key).summary() print "Encrypt the Message:" msg = "Hellllllllllo" uid = "userid that has the key on public key server" enc = gpg.encrypt(msg, uid,always_trust=True) print "*The enc content***************************== ", enc this function written in python gives me encrypted message.The encryption is done using the public key which i am getting from public key server(pramberger.at). Now how can i implement the same functionality (getting the key from any public key server and using that key encrypt the message) in php

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• unable to decrypt certain files with secret key pgp 6.5.8, any advice?

  - by pythonian29033

  Ok so I do some stuff for a client of ours that requires me to decrypt some of their suppliers messages, the thing is, something weird happened the other day and I can only decrypt some files with an old decryption script, but for certain files I get the error: "Message is encrypted. Cannot decrypt message. It can only be decrypted by: 2048 bits, Key ID 98627E12, Created 2000-03-02 "Other Guy "" as you can see, the key is ancient and I was still 9years old when it was created, so I have know idea who this "Other Guy" is. . .and I can't understand why I'm able to decrypt some of the supplier's files with the decryption script, but for others it fails. PS: the supplier only uses one public key, so this should work for all the files, any advice?

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• Implementation of ZipCrypto / Zip 2.0 encryption in java

  - by gomesla

  I'm trying o implement the zipcrypto / zip 2.0 encryption algoritm to deal with encrypted zip files as discussed in http://www.pkware.com/documents/casestudies/APPNOTE.TXT I believe I've followed the specs but just can't seem to get it working. I'm fairly sure the issue has to do with my interpretation of the crc algorithm. The documentation states CRC-32: (4 bytes) The CRC-32 algorithm was generously contributed by David Schwaderer and can be found in his excellent book "C Programmers Guide to NetBIOS" published by Howard W. Sams & Co. Inc. The 'magic number' for the CRC is 0xdebb20e3. The proper CRC pre and post conditioning is used, meaning that the CRC register is pre-conditioned with all ones (a starting value of 0xffffffff) and the value is post-conditioned by taking the one's complement of the CRC residual. Here is the snippet that I'm using for the crc32 public class PKZIPCRC32 { private static final int CRC32_POLYNOMIAL = 0xdebb20e3; private int crc = 0xffffffff; private int CRCTable[]; public PKZIPCRC32() { buildCRCTable(); } private void buildCRCTable() { int i, j; CRCTable = new int[256]; for (i = 0; i <= 255; i++) { crc = i; for (j = 8; j > 0; j--) if ((crc & 1) == 1) crc = (crc >>> 1) ^ CRC32_POLYNOMIAL; else crc >>>= 1; CRCTable[i] = crc; } } private int crc32(byte buffer[], int start, int count, int lastcrc) { int temp1, temp2; int i = start; crc = lastcrc; while (count-- != 0) { temp1 = crc >>> 8; temp2 = CRCTable[(crc ^ buffer[i++]) & 0xFF]; crc = temp1 ^ temp2; } return crc; } public int crc32(int crc, byte buffer) { return crc32(new byte[] { buffer }, 0, 1, crc); } } Below is my complete code. Can anyone see what I'm doing wrong. package org.apache.commons.compress.archivers.zip; import java.io.IOException; import java.io.InputStream; public class ZipCryptoInputStream extends InputStream { public class PKZIPCRC32 { private static final int CRC32_POLYNOMIAL = 0xdebb20e3; private int crc = 0xffffffff; private int CRCTable[]; public PKZIPCRC32() { buildCRCTable(); } private void buildCRCTable() { int i, j; CRCTable = new int[256]; for (i = 0; i <= 255; i++) { crc = i; for (j = 8; j > 0; j--) if ((crc & 1) == 1) crc = (crc >>> 1) ^ CRC32_POLYNOMIAL; else crc >>>= 1; CRCTable[i] = crc; } } private int crc32(byte buffer[], int start, int count, int lastcrc) { int temp1, temp2; int i = start; crc = lastcrc; while (count-- != 0) { temp1 = crc >>> 8; temp2 = CRCTable[(crc ^ buffer[i++]) & 0xFF]; crc = temp1 ^ temp2; } return crc; } public int crc32(int crc, byte buffer) { return crc32(new byte[] { buffer }, 0, 1, crc); } } private static final long ENCRYPTION_KEY_1 = 0x12345678; private static final long ENCRYPTION_KEY_2 = 0x23456789; private static final long ENCRYPTION_KEY_3 = 0x34567890; private InputStream baseInputStream = null; private final PKZIPCRC32 checksumEngine = new PKZIPCRC32(); private long[] keys = null; public ZipCryptoInputStream(ZipArchiveEntry zipEntry, InputStream inputStream, String passwd) throws Exception { baseInputStream = inputStream; // Decryption // ---------- // PKZIP encrypts the compressed data stream. Encrypted files must // be decrypted before they can be extracted. // // Each encrypted file has an extra 12 bytes stored at the start of // the data area defining the encryption header for that file. The // encryption header is originally set to random values, and then // itself encrypted, using three, 32-bit keys. The key values are // initialized using the supplied encryption password. After each byte // is encrypted, the keys are then updated using pseudo-random number // generation techniques in combination with the same CRC-32 algorithm // used in PKZIP and described elsewhere in this document. // // The following is the basic steps required to decrypt a file: // // 1) Initialize the three 32-bit keys with the password. // 2) Read and decrypt the 12-byte encryption header, further // initializing the encryption keys. // 3) Read and decrypt the compressed data stream using the // encryption keys. // Step 1 - Initializing the encryption keys // ----------------------------------------- // // Key(0) <- 305419896 // Key(1) <- 591751049 // Key(2) <- 878082192 // // loop for i <- 0 to length(password)-1 // update_keys(password(i)) // end loop // // Where update_keys() is defined as: // // update_keys(char): // Key(0) <- crc32(key(0),char) // Key(1) <- Key(1) + (Key(0) & 000000ffH) // Key(1) <- Key(1) * 134775813 + 1 // Key(2) <- crc32(key(2),key(1) >> 24) // end update_keys // // Where crc32(old_crc,char) is a routine that given a CRC value and a // character, returns an updated CRC value after applying the CRC-32 // algorithm described elsewhere in this document. keys = new long[] { ENCRYPTION_KEY_1, ENCRYPTION_KEY_2, ENCRYPTION_KEY_3 }; for (int i = 0; i < passwd.length(); ++i) { update_keys((byte) passwd.charAt(i)); } // Step 2 - Decrypting the encryption header // ----------------------------------------- // // The purpose of this step is to further initialize the encryption // keys, based on random data, to render a plaintext attack on the // data ineffective. // // Read the 12-byte encryption header into Buffer, in locations // Buffer(0) thru Buffer(11). // // loop for i <- 0 to 11 // C <- buffer(i) ^ decrypt_byte() // update_keys(C) // buffer(i) <- C // end loop // // Where decrypt_byte() is defined as: // // unsigned char decrypt_byte() // local unsigned short temp // temp <- Key(2) | 2 // decrypt_byte <- (temp * (temp ^ 1)) >> 8 // end decrypt_byte // // After the header is decrypted, the last 1 or 2 bytes in Buffer // should be the high-order word/byte of the CRC for the file being // decrypted, stored in Intel low-byte/high-byte order. Versions of // PKZIP prior to 2.0 used a 2 byte CRC check; a 1 byte CRC check is // used on versions after 2.0. This can be used to test if the password // supplied is correct or not. byte[] encryptionHeader = new byte[12]; baseInputStream.read(encryptionHeader); for (int i = 0; i < encryptionHeader.length; i++) { encryptionHeader[i] ^= decrypt_byte(); update_keys(encryptionHeader[i]); } } protected byte decrypt_byte() { byte temp = (byte) (keys[2] | 2); return (byte) ((temp * (temp ^ 1)) >> 8); } @Override public int read() throws IOException { // // Step 3 - Decrypting the compressed data stream // ---------------------------------------------- // // The compressed data stream can be decrypted as follows: // // loop until done // read a character into C // Temp <- C ^ decrypt_byte() // update_keys(temp) // output Temp // end loop int read = baseInputStream.read(); read ^= decrypt_byte(); update_keys((byte) read); return read; } private final void update_keys(byte ch) { keys[0] = checksumEngine.crc32((int) keys[0], ch); keys[1] = keys[1] + (byte) keys[0]; keys[1] = keys[1] * 134775813 + 1; keys[2] = checksumEngine.crc32((int) keys[2], (byte) (keys[1] >> 24)); } }

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• Is zip's encryption really bad?

  - by Nifle

  The standard advice for many years regarding compression and encryption has been that the encryption strength of zip is bad. Is this really the case in this day and age? I read this article about WinZip (it has had the same bad reputation). According to that article the problem is removed provided you follow a few rules when choosing your password. At least 12 characters in length Be random not contain any dictionary, common words or names At least one Upper Case Character Have at least one Lower Case Character Have at least one Numeric Character Have at least one Special Character e.g. $,£,*,%,&,! This would result in roughly 475,920,314,814,253,000,000,000 possible combinations to brute force Please provide recent (say past five years) links to back up your information.

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• How secure is Microsoft 2007's encryption?

  - by ericl42

  I've read some various articles about Microsoft's encryption, and from what I gather, 2007 is secure using all default options due to it using AES, and 2000 and 2003 can be configured secure by changing the default algorithm to AES. I was wondering if anyone else has read any other articles or know of any specific vulnerabilities involved with how they implement the encryption. I would like to be able to tell users that they can use this to send semi sensitive documents as long as they use AES and a strong password. Thanks for the information.

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• Encryption of external HDD -- accessible from windows without installation

  - by Rainer

  I would like to use encryption on my external HDD but I would like to be able to access the encrypted data from Windows as well. As suggested in other questions, TrueCrypt is one option here, or I am using momentarily encfs, which is not available for Windows. But my question goes further: I would like to be able to access the encrypted partition from Windows without installation as I will be using it from different Windows machines for which I have no administrator access. My main OS is Linux and I have full root access to that computer. Is there a full disk or file based encryption which I can use cross platform and which does not require installation under Windows? ADDITION: It seems that TrueCrypt provides a portable mode which fulfills my requirements partly: http://www.truecrypt.org/docs/?s=truecrypt-portable, but still the TrueCrypt driver needs to be installed by an administrator... pitty Thanks

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• Using TrueCrypt (software encryption) with an SSD

  - by Shackrock

  I use full drive encryption (FDE) w/ TrueCrypt on my laptop. I have a 2nd gen I7 with AES instruction support, so honestly I can't even notice a speed change on the system with it on. My question, is for those who know about SSD's a lot. I previously (early 2011) read articles about how software encryption will negate the speed benefits that an SSD provides - because of the need for the SSD to send a delete command, then a write command, for every encrypted write - instead of just writing over data like a regular HDD would (or something like this...honestly I can't remember...ha!). Anyway, any improvements in this field? Is it pointless for me to grab an SSD if I'm using FDE? Thanks all.

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• Windows XP: how to disable automatic encryption on downloaded files

  - by T. Webster

  I have Windows XP SP3 and every file I download is automatically encrypted no matter what directory I save the downloaded file in. So it's not as simple as turning off encryption of any specific directory, the file will be downloaded as encrypted regardless of whether the directory is encrypted or not. Is there a policy or registry setting somewhere to disable this automatic encryption? (EDIT: I doubt it's malware since this OS was just installed on this machine. It's my work PC and by default I think there's some group policy or other setting which not only sets everything in My Documents to encrypted, but also everything I download, no matter where it's downloaded to. )

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• tripledes encryption not yielding same results in PHP and C#

  - by Jones

  When I encrypt with C# I get arTdPqWOg6VppOqUD6mGITjb24+x5vJjfAufNQ4DN7rVEtpDmhFnMeJGg4n5y1BN static void Main(string[] args) { Encoding byteEncoder = Encoding.Default; String key = "ShHhd8a08JhJiho98ayslcjh"; String message = "Let us meet at 9 o'clock at the secret place."; String encryption = Encrypt(message, key, false); String decryption = Decrypt(encryption , key, false); Console.WriteLine("Message: {0}", message); Console.WriteLine("Encryption: {0}", encryption); Console.WriteLine("Decryption: {0}", decryption); } public static string Encrypt(string toEncrypt, string key, bool useHashing) { byte[] keyArray; byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt); if (useHashing) { MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider(); keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key)); } else keyArray = UTF8Encoding.UTF8.GetBytes(key); TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider(); tdes.Key = keyArray; tdes.Mode = CipherMode.ECB; tdes.Padding = PaddingMode.PKCS7; ICryptoTransform cTransform = tdes.CreateEncryptor(); byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length); return Convert.ToBase64String(resultArray, 0, resultArray.Length); } public static string Decrypt(string toDecrypt, string key, bool useHashing) { byte[] keyArray; byte[] toEncryptArray = Convert.FromBase64String(toDecrypt); if (useHashing) { MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider(); keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key)); } else keyArray = UTF8Encoding.UTF8.GetBytes(key); TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider(); tdes.Key = keyArray; tdes.Mode = CipherMode.ECB; tdes.Padding = PaddingMode.PKCS7; ICryptoTransform cTransform = tdes.CreateDecryptor(); byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length); return UTF8Encoding.UTF8.GetString(resultArray); } When I encrypt with PHP I get: arTdPqWOg6VppOqUD6mGITjb24+x5vJjfAufNQ4DN7rVEtpDmhFnMVM+W/WFlksR <?php $key = "ShHhd8a08JhJiho98ayslcjh"; $input = "Let us meet at 9 o'clock at the secret place."; $td = mcrypt_module_open('tripledes', '', 'ecb', ''); $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND); mcrypt_generic_init($td, $key, $iv); $encrypted_data = mcrypt_generic($td, $input); mcrypt_generic_deinit($td); mcrypt_module_close($td); echo base64_encode($encrypted_data); ?> I don't know enough about cryptography to figure out why. Any ideas? Thanks.

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• TDE Tablespace Encryption 11.2.0.1 Certified with EBS 11i

  - by Steven Chan

  Oracle Advanced Security is an optional licenced Oracle 11g Database add-on.  Oracle Advanced Security Transparent Data Encryption (TDE) offers two different features:  column encryption and tablespace encryption.  TDE Tablespace Encryption 11.2.0.1 is now certified with Oracle E-Business Suite Release 11i. What is Transparent Data Encryption (TDE) ? Oracle Advanced Security Transparent Data Encryption (TDE) allows you to protect data at rest. TDE helps address privacy and PCI requirements by encrypting personally identifiable information (PII) such as Social Security numbers and credit card numbers. TDE is completely transparent to existing applications with no triggers, views or other application changes required. Data is transparently encrypted when written to disk and transparently decrypted after an application user has successfully authenticated and passed all authorization checks. Authorization checks include verifying the user has the necessary select and update privileges on the application table and checking Database Vault, Label Security and Virtual Private Database enforcement policies.

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• violation of primary key constraint .Cannot insert duplicate key in object using ADO

  - by CREFLY

  Hi All we are working on a users apllication using Access2003(VBA) as software language and SQL Server 2005 as database. We are using ADO method and we encounter a problem. when users create new record in a ADO Screen and they want to save the record after implementing it they receive this error : error -2147217873 violation of primary key constraint 'PK_ '.Cannot insert duplicate key in object 'Pk_...' Any help will be appreciated Thanks in advance

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• BitLocker with Windows DPAPI Encryption Key Management

  - by bigmac

  We have a need to enforce resting encryption on an iSCSI LUN that is accessible from within a Hyper-V virtual machine. We have implementing a working solution using BitLocker, using Windows Server 2012 on a Hyper-V Virtual Server which has iSCSI access to a LUN on our SAN. We were able to successfully do this by using the "floppy disk key storage" hack as defined in THIS POST. However, this method seems "hokey" to me. In my continued research, I found out that the Amazon Corporate IT team published a WHITEPAPER that outlined exactly what I was looking for in a more elegant solution, without the "floppy disk hack". On page 7 of this white paper, they state that they implemented Windows DPAPI Encryption Key Management to securely manage their BitLocker keys. This is exactly what I am looking to do, but they stated that they had to write a script to do this, yet they don't provide the script or even any pointers on how to create one. Does anyone have details on how to create a "script in conjunction with a service and a key-store file protected by the server’s machine account DPAPI key" (as they state in the whitepaper) to manage and auto-unlock BitLocker volumes? Any advice is appreciated.

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• Using datetime float representation as primary key

  - by devanalyst

  From my experience I have learn that using an surrogate INT data type column as primary key esp. an IDENTITY key column offers better performance than using GUID or char/varchar data type column as primary key. I try to use IDENTITY key as primary key wherever possible. But recently I came across a schema where the tables were horizontally partitioned and were managed via a Partitioned view. So the tables could not have an IDENTITY column since that would make the Partitioned View non updatable. One work around for this was to create a dummy 'keygenerator' table with an identity column to generate IDs for primary key. But this would mean having a 'keygenerator' table for each of the Partitioned View. My next thought was to use float as a primary key. The reason is the following key algorithm that I devised DECLARE @KEY FLOAT SET @KEY = CONVERT(FLOAT,GETDATE())/100000.0 SET @KEY = @EMP_ID + @KEY Heres how it works. CONVERT(FLOAT,GETDATE()) gives float representation of current datetime since internally all datetime are represented by SQL as a float value. CONVERT(FLOAT,GETDATE())/100000.0 converts the float representation into complete decimal value i.e. all digits are pushed to right side of ".". @KEY = @EMP_ID + @KEY adds the Employee ID which is an integer to this decimal value. The logic is that the Employee ID is guaranteed to be unique across sessions since an employee cannot connect to an application more than once at the same time. And for the same employee each time a key will be generated the current datetime will be unique. In all an unique key across all employee sessions and across time. So for Emp Ids 11 and 12, I have key values like 12.40046693321566357, 11.40046693542361111 But my concern whether float data type as primary key offer benefits compared to choosing GUID or char/varchar as primary keys. Also important thing is because of partitioning the float column is going to be part of a composite key.

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• WP: AesManaged encryption vs. mcrypt_encrypt

  - by invalidusername

  I'm trying to synchronize my encryption and decryption methods between C# and PHP but something seems to be going wrong. In the Windows Phone 7 SDK you can use AESManaged to encrypt your data I use the following method: public static string EncryptA(string dataToEncrypt, string password, string salt) { AesManaged aes = null; MemoryStream memoryStream = null; CryptoStream cryptoStream = null; try { //Generate a Key based on a Password, Salt and HMACSHA1 pseudo-random number generator Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(password, Encoding.UTF8.GetBytes(salt)); //Create AES algorithm with 256 bit key and 128-bit block size aes = new AesManaged(); aes.Key = rfc2898.GetBytes(aes.KeySize / 8); aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; // rfc2898.GetBytes(aes.BlockSize / 8); // to check my results against those of PHP var blaat1 = Convert.ToBase64String(aes.Key); var blaat2 = Convert.ToBase64String(aes.IV); //Create Memory and Crypto Streams memoryStream = new MemoryStream(); cryptoStream = new CryptoStream(memoryStream, aes.CreateEncryptor(), CryptoStreamMode.Write); //Encrypt Data byte[] data = Encoding.Unicode.GetBytes(dataToEncrypt); cryptoStream.Write(data, 0, data.Length); cryptoStream.FlushFinalBlock(); //Return Base 64 String string result = Convert.ToBase64String(memoryStream.ToArray()); return result; } finally { if (cryptoStream != null) cryptoStream.Close(); if (memoryStream != null) memoryStream.Close(); if (aes != null) aes.Clear(); } } I solved the problem of generating the Key. The Key and IV are similar as those on the PHP end. But then the final step in the encryption is going wrong. here is my PHP code <?php function pbkdf2($p, $s, $c, $dk_len, $algo = 'sha1') { // experimentally determine h_len for the algorithm in question static $lengths; if (!isset($lengths[$algo])) { $lengths[$algo] = strlen(hash($algo, null, true)); } $h_len = $lengths[$algo]; if ($dk_len > (pow(2, 32) - 1) * $h_len) { return false; // derived key is too long } else { $l = ceil($dk_len / $h_len); // number of derived key blocks to compute $t = null; for ($i = 1; $i <= $l; $i++) { $f = $u = hash_hmac($algo, $s . pack('N', $i), $p, true); // first iterate for ($j = 1; $j < $c; $j++) { $f ^= ($u = hash_hmac($algo, $u, $p, true)); // xor each iterate } $t .= $f; // concatenate blocks of the derived key } return substr($t, 0, $dk_len); // return the derived key of correct length } } $password = 'test'; $salt = 'saltsalt'; $text = "texttoencrypt"; #$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC); #echo $iv_size . '<br/>'; #$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); #print_r (mcrypt_list_algorithms()); $iv = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"; $key = pbkdf2($password, $salt, 1000, 32); echo 'key: ' . base64_encode($key) . '<br/>'; echo 'iv: ' . base64_encode($iv) . '<br/>'; echo '<br/><br/>'; function addpadding($string, $blocksize = 32){ $len = strlen($string); $pad = $blocksize - ($len % $blocksize); $string .= str_repeat(chr($pad), $pad); return $string; } echo 'text: ' . $text . '<br/>'; echo 'text: ' . addpadding($text) . '<br/>'; // -- works till here $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_CBC, $iv); echo '1.' . $crypttext . '<br/>'; $crypttext = base64_encode($crypttext); echo '2.' . $crypttext . '<br/>'; $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, addpadding($text), MCRYPT_MODE_CBC, $iv); echo '1.' . $crypttext . '<br/>'; $crypttext = base64_encode($crypttext); echo '2.' . $crypttext . '<br/>'; ?> So to point out, the Key and IV look similar on both .NET and PHP, but something seems to be going wrong in the final call when executing mcrypt_encrypt(). The end result, the encrypted string, differs from .NET. Can anybody tell me what i'm doing wrong. As far as i can see everything should be correct. Thank you! EDIT: Additional information on the AESManaged object in .NET Keysize = 256 Mode = CBC Padding = PKCS7

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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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• Security of BitLocker with no PIN from WinPE?

  - by Scott Bussinger

  Say you have a computer with the system drive encrypted by BitLocker and you're not using a PIN so the computer will boot up unattended. What happens if an attacker boots the system up into the Windows Preinstallation Environment? Will they have access to the encrypted drive? Does it change if you have a TPM vs. using only a USB startup key? What I'm trying to determine is whether the TPM / USB startup key is usable without booting from the original operating system. In other words, if you're using a USB startup key and the machine is rebooted normally then the data would still be protected unless an attacker was able to log in. But what if the hacker just boots the server into a Windows Preinstallation Environment with the USB startup key plugged in? Would they then have access to the data? Or would that require the recovery key? Ideally the recovery key would be required when booted like this, but I haven't seen this documented anywhere.

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