How do I restore the public key?

Let say, I create wallet and have two public key and one private key.

And I remove the first public key from the wallet.

Can I restore and use my first key again? Or it’s removed at all.

database design – MySQL: Should I add NOT NULL UNIQUE to the field for primary key?

Hi I’m completely new to MySQL, I’m creating a database and my question is that:

Should I add NOT NULL UNIQUE to the field for primary key?

For example I have:

CREATE TABLE Account (
    AccountID varchar(25) NOT NULL,
    ...
    PRIMARY KEY(AccountID)           // <------- (*)

I’m thinking about whether the (*) would implicitly mark the field as UNIQUE NOT NULL.

Btw, could anyone provide good resources about best practices of MySQL(I’m currently interested about creating table) so I won’t add redundant restriction(s) in any schema.

deletion – Does certutil -delkey actually delete the certificate and private key?

I am trying to delete a certificate and it’s private key using certutil -csp "Microsoft Enhanced Cryptographic Provider v1.0" -delkey "the key container". This gave me a command completed successfully message. I then check what is in the store again with certutil -store,
this still lists the certificate. When i then try to delete again, it gives me KeySet does not exists.
Can someone explain what the -delkey option and why it still appears in the output?

magento2.3 – how to change URL KEY for Search Engine Optimization

in my case i want to change the url key for the tab ‘SEO’ in the ‘product edit’,i want to concatenate the name of the product with another variable, for all the product, but i don’t know when Magento declares this “url key” variable

can anyone help me please

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key management – How does a Certificate get associated to the private key pair?

I am new to SSL certs and trying to understanding once the certificate is imported into the Certificate Store (in Windows), how does the certificate get associated with the private key pair? Is that by creating a pfx that would contain the certificate and private key and import that pfx into Certificate Store? We intent to use the TPM to store the private key (but not using it to generate the keypair). How do we tell the certificate store where the associated private key is to a certificate?

key management – How does a Certificate bind to the private key?

I am new to SSL certs and trying to understanding once the certificate is imported into the Certificate Store (in Windows), how does the private key get binded to that certificate that holds the public key of the keypair? Is that by creating a pfx that would contain the certificate and private key and import that pfx into Certificate Store? We intent to use the TPM to store the private key (but not using it to generate the keypair). How do we tell the certificate store where the private key is?

percona cluster victim thread on duplicate key updates

Recently, I’ve been getting this in the log and its creating chaos when not addressed. I totally understand the error, but what are the typical sources of this showing up in the cluster. I’ve been running previous versions without any issues and this has started popping up after upgrade to 8.x. Has anyone dealt with that? My cluster is behind roundrobin loadlabancer and I’m thinking of changing that, but in my opinion the cluster should be able to take care of this. Can this be tweaked with some configs ?

(Note) (MY-000000) (WSREP) Victim thread:
THD: 152232, mode: local, state: exec, conflict: certifying, seqno: -1
SQL: INSERT INTO session (data, id, expire) VALUES (‘__flash|a:0:18;’, ‘dasd’, 1621267611) ON DUPLICATE KEY UPDATE data=VALUES(data), expire=VALUES(expire)

recover private key – is there a way to find the wallet that my address goes to ?//

I two years ago had a cash out from a casino and i went to myapp store and downloaded what I was coinbase wallet which it was the cold storage wallet that really has no ties beside a wallet connect to coinbase I later figured out. I was brand new to btc and knew nothing about 12 words that i was to immediately write down. I did make an account at wallet.coinbase.com/kristymoser2018 is what I thought was it. I later on saw the money come into my wallet from the casino and at that point it shut my phone down and erased eveything.. when I came back online I found out that I no longer had an account at wallet under the credentials I thought were right

I guess what I am asking is there any other way to figure out where the wallet is cause it still has the money in it and is there any program I can use that may help me figure out where it is and if my private key is in cloud storage?

I have tried to recreate the same scenarfio and have never been ABLE TO understand this

private key – Can Bitcoin be recovered from a child key alone?

I have a question regarding BIP-32 and keys.

Imagine a scenario in which a user creates a new Bitcoin wallet with a seed phrase. He then generates a new address and sends 1 BTC to this address.

Under the covers, my understanding is that a master private/public key will be created from the seed phrase. Then, a child key is created under the parent key for the address.

Now, suppose this user completely loses their seed phrase / master keys, BUT they somehow have a copy of the child key pair that contains their Bitcoin.

Is it possible to recover their Bitcoin from that child key alone? If so, what is the process? Are individual child keys just the same as normal (non BIP-32) key/pairs?

Thanks!

ssh -Q key not listing all key types?

I am having some problems with understanding which types of host keys my SSH daemon actually provides or supports (stock debian buster, sshd 7.9.p1). From the manual (man sshd_config):

 HostKeyAlgorithms
         Specifies the host key algorithms that the server offers.  The default for this option is:

            ecdsa-sha2-nistp256-cert-v01@openssh.com,
            ecdsa-sha2-nistp384-cert-v01@openssh.com,
            ecdsa-sha2-nistp521-cert-v01@openssh.com,
            ssh-ed25519-cert-v01@openssh.com,
            rsa-sha2-512-cert-v01@openssh.com,rsa-sha2-256-cert-v01@openssh.com,
            ssh-rsa-cert-v01@openssh.com,
            ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,
            ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa

         The list of available key types may also be obtained using "ssh -Q key".

Please note the last line. When following the advice given there:

root@odysseus /var/log # ssh -Q key
ssh-ed25519
ssh-ed25519-cert-v01@openssh.com
ssh-rsa
ssh-dss
ecdsa-sha2-nistp256
ecdsa-sha2-nistp384
ecdsa-sha2-nistp521
ssh-rsa-cert-v01@openssh.com
ssh-dss-cert-v01@openssh.com
ecdsa-sha2-nistp256-cert-v01@openssh.com
ecdsa-sha2-nistp384-cert-v01@openssh.com
ecdsa-sha2-nistp521-cert-v01@openssh.com

I’ve got two questions:

  1. As an example, the man page states that rsa-sha2-256 is part of the default for HostKeyAlgorithms. But this string does not appear in the output of ssh -Q key.

    How does this fit together? How can something be a default which even doesn’t exist?

    The above example implies that ssh-rsa might be insecure, because it doesn’t have sha2 in its name, and thus might be sha1 or even md5 based (of course, my host keys are actually created by ssh-keygen with sha2-256 fingerprint, so that actually can’t be a problem, but I’d like to understand those key type names nevertheless).

  2. What does the string -cert-v01@openssh.com in some of the algorithm type names mean? Are these the types for certificate-based authentication?