I'm trying to use an application external to SQL Server to decrypt data (that I've) encrypted in Azure SQL Database. I can decrypt it natively in SQL Server using DecryptByKey - but I want to do this on the client computer. I know the key_source parameter used to generate the key and I can decode the initialisation vector and cipher data from the field data thanks to this SO post.
The key is being created by:
create symmetric key #tempkey
with algorithm = AES_256,
key_source='*****'
encryption by password = '*****'
I'm not able to find a reference to the key-derivation algorithm used by SQL server to convert the key_source into
the actual key. Sqlity says that the details are not published, however this blog article is getting old now - and I'm hoping that's changed.
Inspecting the key information in sys.key_encryptions:
key_id|thumbprint|crypt_type|crypt_type_desc|crypt_property
259|NULL|ESP2|ENCRYPTION BY PASSWORD V2|NULL
sys.symmetric_keys doesn't appear to yield anything of use
There is a similar SO question here; but the answer refers to using a stored procedure to complete the decryption - which is not what I want to do.
Can anyone point me in the right direction of the key derivation algorithm implementation so that given the known key_source, I can generate the symmetric encryption key value and decrypt the cipher data?
My work-around is to do both encryption and decryption outside of SQL Server, but I'd like to avoid that if I can.
Related
CREATE MASTER KEY ENCRYPTION
BY PASSWORD = 'abcdefg'
GO
CREATE CERTIFICATE EncryptTestCert
WITH SUBJECT = 'FirstCertificateBYShashank'
GO
CREATE SYMMETRIC KEY SYM_TDES_FOR_IDS
WITH ALGORITHM = TRIPLE_DES
ENCRYPTION BY CERTIFICATE EncryptTestCert
GO
When I am trying to run this I got the below error
Incorrect syntax near 'TRIPLE_DES'
Beginning with SQL Server 2016 (13.x), all algorithms other than AES_128, AES_192, and AES_256 are deprecated. To use older algorithms (not recommended) you must set the database to database compatibility level 120 or lower.
See more information here Choose an Encryption Algorithm
I am new to the AES encryption and reading about it.
We used to send data in .csv format with MD5 encryption but last week I got a requirement to send the data in AES encrypted format to client rather than MD5.
I have read some internet I did the following step
-- Create database key
CREATE MASTER KEY ENCRYPTION BY PASSWORD = 'Password123'
-- Create self-signed certificate
CREATE CERTIFICATE Certificate1
WITH SUBJECT = 'Protect Data';
GO
-- Create symmetric key
CREATE SYMMETRIC KEY SymmetricKey1
WITH ALGORITHM = AES_256
ENCRYPTION BY CERTIFICATE Certificate1;
GO
Then to encrypt the data I have used
OPEN SYMMETRIC KEY SymmetricKey1
DECRYPTION BY CERTIFICATE Certificate1;
Select EncryptByKey (Key_GUID('SymmetricKey1'),columnName)
From TableName
CLOSE SYMMETRIC KEY SymmetricKey1;
I tried to encrypt and decrypt and It works fine and I have sent the data but client has a different server want to decrypt the file and they are asking me to send the KEY
I suppose the key is 'SymmetricKey1'
But Client is not able to decrypt it.
Now my question is if the certificate and symmetric key is in 1 SQL server(suppose india) and client want to decrypt the file in some other server what exactly I need to provide him.DO I need to create the same certificate and key on the client server or something else.
I may sound little stupid but sorry I could not find much in internet
I am writing a SSL Client using openSSL library. I am able to connect to https://www.httpbin.org using my C program. However, i want to manually set my own AES key for further symmetric cryptography and notify the server about key. I know that key for symmetric encryption is set during handshake process. I am using SSL_connect() to connect to server.
How can i manually set key for symmetric cryptography?
This is not possible. The key used for encryption depends on data created by both server and client. This means it is not possible to for the client to have full control over the key value. See also Computing the Master Secret in RFC 5246 (TLS 1.2).
I want to decrypt passwords stored in my database on Sql Server 2008 which were encrypted using Exec master.dbo.xp_sha1 #Password, #EncPassword output .Is it possible to decrypt?
encrypted passwords look like this : xxstgggettebbqyyayujjweee
Thanks
xp_sha1 is a not standard master stored procedure, it is not included in any sql server i've seen, but doing a quick google i came across: http://www.xpcrypt.com/xpho/xp_sha1.htm
As I stated in my answer/comments in your question Encrypt passwords on Sql Server 2008 using SHA1 encryption is not the same thing as hashing. SHA1 is a hash, not an encryption. Encryption can be undone, hashing cannot.
The links called out in the answer for the last question go through this in some detail, but here are several articles specifically around the differences between encryption and hashing:
Difference between Hashing a Password and Encrypting it
http://www.darkreading.com/safely-storing-user-passwords-hashing-vs-encrypting/a/d-id/1269374
Please Understand that there is a fundamental difference between encrypting and hashing.
If you encrypt "password" to "123809dsfajsfoiwj" as an example, knowing the key and encryption method, you can arrive back at "password" through an appropriate decrypt.
Using SHA1 and hashing "password" there is no way to ever reverse the hashed "jdsfioajd0f98uas" (example) back to the original "password". Hashes are created the same each time given the same input, so hashes are compared to hashes for "validating passwords". You never arrive back at the original.
I have backed up an encrypted DB (symmetric key/certificate) and
restored it on a different server.
Unfortuantely we're having problems with the decryption... hoping
someone can help.
In the restored db, I can see the Symmetric Key and the Certificate in
SSMS, but when I try to Open the key using the cert ( open symmetric
key KeyA decryption by certificate CertB )I get the
following very descriptive error:
Msg 15466, Level 16, State 1, Line 1
An error occurred during decryption.
Any ideas?
Thanks in advance.
http://blogs.msdn.com/lcris/archive/2007/11/16/sql-server-2005-restoring-the-backup-of-a-database-that-uses-encryption.aspx answers this:
"When you restore a database that uses encryption features, there is only one thing you need to take care off - if the database master key (DbMK) needs a service master key (SMK) encryption, you need to regenerate this encryption. Note that this encryption is made by default when you create the DbMK, but it may be intentionally dropped, if you want tighter control of access to the encrypted data. Anyway, if you did have such SMK encryption for the DbMK, the steps to regenerate it are the following:
OPEN MASTER KEY DECRYPTION BY PASSWORD = 'password'
ALTER MASTER KEY ADD ENCRYPTION BY SERVICE MASTER KEY
CLOSE MASTER KEY
That's it - the database encryption features should now work as when the backup was taken. Also note that it doesn't matter if you restore the database on the server where the backup was taken or elsewhere. The only thing that matters for this procedure is that you know one of the passwords protecting the DbMK "
The master key was decrypted by the service master key on the source server and we were decrypting the master key with password on the destination. I altered the master key to be decrypted by the service master key and it's working now.
The problem you are probably experiencing is that the Database Master Key for the servers is different. To my understanding the other keys are based off of this and it could cause problems when trying to decrypt the data. Check out the encryption hierarchy for a description of the steps that go into data encryption.
I hope this answer helps and isn't too off-track. :)
http://social.msdn.microsoft.com/forums/en-US/sqlsecurity/thread/34c9c35c-2d08-4873-abfd-aae40240dfe7/?prof=required
That link worked for me, follow the 2 links to backup/restore
You can do the restore from the destination server using a UNC, you do not have to copy the file.