public-key

I want to create a X509 certificate using Java language and then extract public key from it. I have searched the internet and found many code examples, but all of them have errors (unknown variable or unknown type) or have many warnings that say something like : "the method ... from type ... is deprecated " etc. For example, why the following code doesn't work: PublicKey pk; CertificateFactory cf = CertificateFactory.getInstance("X.509"); String PKstr = pk.toString(); InputStream PKstream = new ByteArrayInputStream(PKstr.getBytes()); X509Certificate pkcert = (X509Certificate)cf

We're trying to implement some functionality of a Web-Service from one of our partners. Now, the content which is beeing transmitted, should be encrypted with a public key, which we have to provide. The security-specification says that the public-certificate has to be X.509 standard. Doesn't X.509 rely on the private / public key method? Because I only get one .pem file, containing a private key, and a certificate, but no public key, using the following command: openssl req -new -x509 -days 365 -nodes -out ./cert.pem -keyout ./cert.pem Do I have to modify the command in order to create a

In order to send and receive encrypted messages from/to the iPhone I need to read a public key (server's public key) PEM file and create a SecKeyRef (later I could even store it on the keychain in order not to create it again). This is my current workflow: On the server: Create a P12 file with the user's certificate and private key. Store the user's public key on the server's keychain. On the iPhone: Retrieve the P12 file from the server, use the password to open it and store the private key on the keychain. On the iPhone: Retrieve a PEM file with the server's public key from the server.

I have a web server built up relying on HTTPS. So, my server maintains its private key and publish a public key that any clients can use to encrypt their request. Since my server is the only one who has the private key to decrypt any message encryped using server's public key, any request sent this way can be considered secure. However my question is at the response part. When the server sends the response back to the client, whose public key will the server use to encrypt the response message? I assume the server will use client's public key to encrypt the response (by default? or upon

For RSA, how do i calculate the secret exponent? Given p and q the two primes, and phi=(p-1)(q-1), and the public exponent (0x10001), how do i get the secret exponent 'd' ? I've read that i have to do: d = e -1 mod phi using modular inversion and the euclidean equation but i cannot understand how the above formula maps to either the a -1 ≡ x mod m formula on the modular inversion wiki page, or how it maps to the euclidean GCD equation. Can someone help please, cheers You can use the extended Euclidean algorithm to solve for d in the congruence de = 1 mod phi(m) For RSA encryption, e is the

can anyone please help me with this, i have been instructed to write an application that takes some DATA then Encrypts it with a RSA Public Key and apparently needs to be RSA Encryption(i have never heard or seen this before)? Which encryption cipher is RSA meant to use as standard? var key = "TUlHZE1BMEdDU3FHU0liM0RRRUJBUVVBQTRHTEFEQ0Jod0tCZ1FDbVFiTWc3SWRpeHVmYWEwcDd2ODVLVytmUnVlZ216UUhibnNoWjhmbXlTQW9MMXRFVzAyNEZKVFlSTFZxN0VsV2p1R0U4aHQ3RmJjN1NURWpxZVViWU5xdnRiVWN6UFZYSE5FdStYRUVndGszazlFNXVQWG0wVzRIc3RtK0FhRXcyMmxxb2lFNGlrT1QzZzdPRXNHSVFCMVNlSlRtVTE1eFBBZ3M3SXRjTVFRSUJFUT09"; var data =

I've researched a bit about how to achieve what I said in the question and found several APIs but most of them look very complicated and since I'm just a noobie in this area I just want a simple method like: public String Encrypt(String message, PublicKey publicKey) Don't know if this can be done? If not then please someone enlighten me another way to achieve this :) Thank you. UPDATE: So far I have only seen that all of the library for OpenPGP encryption require both the public key and private key to do the encrypt while I only want to encrypt with the public key (because I don't have the