I generated a pair of self-signed priv/pub keys using the following command:
openssl req -x509 -sha256 -nodes -days 36500 -newkey rsa:2048 -keyout signing_logs.key -out signing_logs.crtopenssl x509 -in signing_logs.crt -pubkey -noout > signing_logs.pub
Then I signed a file, e.g.
openssl dgst -sha256 -sign signing_logs.key -out foobar.log.sha256 foobar.log
and able to verify the corresponding signature:
openssl dgst -sha256 -verify signing_logs.pub -signature foobar.log.sha256 foobar.log
What I'd like to accomplish is just a two-step verification, not just using a single command. In other words, first I'd like to decrypt the signature using the pub key to obtain the original alphanumeric sha256 hash, then I want to compare this hash with the one produced by the following command:
openssl dgst -sha256 foobar.log
I already tried the following commands, but I didn't get an alphanumeric hash:
openssl rsautl -inkey signing_logs.pub -pubin -in foobar.log.sha256openssl rsautl -asn1parse -inkey signing_logs.pub -pubin -in foobar.log.sha256
What is the right command?
This is a question that has been on my mind for quite some time now. Is it actually possible to split the workload of the SHA-256 between two or more computers which are working in parallel with each other? If so, are there any examples you can show me? Your opinions are welcome. Please tell me if you think such a system would be beneficial or if you think it would be inefficient.
How can I retrieve salt from MySql database using Asp.Net ?
I want to use that retrieved salt to add to the user entered password to generate an SHA256 hash and then authenticate the user.
Here is what I am trying to do to fetch the salt:
String userNameEntered = UserN_TextBox.Text;String passwordEntered = Password_TextBox.Text;String connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();connection = new MySqlConnection(connectionString);connection.Open();MessageBox.Show("Successfully connected to database");String queryString = "select salt from xyz.abc_table where salt = @Salt";command = new MySqlCommand(queryString, connection);command.Parameters.AddWithValue("@Salt", queryString);reader = command.ExecuteReader();Response.Write("Salt retrived is" + reader);reader.Close();connection.Close();
When I execute this code, it returns the MySql Data Reader library rather than the salt in the database....
Thanks in advance... :)
As I know sha2 generate 256 bit hash.
256bit/8 = 32bytes.
So, It should take only varchar(32) field in the database. But I saw an article saying sah2 database field require varchar(64) field in the database. Is that true? Can someone explain, Please!!
If I started with a sha256 hash such as
and rehashed it continuously (without salting):
i) What is the shortest time it would take before it started cycling in a loop or back onto the same value if at all?
ii) If it did cycle back on itself, could we assume that it had been cracked?
iii) How long would this take using modern GPU cracking techniques?
iv) If all the intermediary hashes were recorded in some kind of rainbow tables - presumably all the hashes within that cycle would be compromised?
v) What is to stop someone computing these cycles and offering cracks to sha256 hashes - likewise for other hashing protocols...
For Extra marks - What is the probability this question would be asked in this forum 60 billion years ago?