Ruby Openssl Generate Rsa Key
- The opensslrsaprivatekey resource has the following properties. Force Ruby Type: true, false Default Value: false Force creation of the key even if the same key already exists on the node. Group Ruby Type. String, Integer The group ownership applied to all files created by the resource.
- While Encrypting a File with a Password from the Command Line using OpenSSL is very useful in its own right, the real power of the OpenSSL library is its ability to support the use of public key cryptograph for encrypting or validating data in an unattended manner (where the password is not required to encrypt) is done with public keys.
- Class OpenSSL::X509::Certificate Implementation of an X.509 certificate as specified in RFC 5280. Provides access to a certificate's attributes and allows certificates to be read from a string, but also supports the creation of new certificates from scratch.
- Encryption ¶ ↑. The strategy is to first instantiate a Cipher for encryption, and then to generate a random IV plus a key derived from the password using PBKDF2. PKCS #5 v2.0 recommends at least 8 bytes for the salt, the number of iterations largely depends on the hardware being used.
- An AES-128 expects a key of 128 bit, 16 byte. To generate such a key, use OpenSSL as: openssl rand 16 myaes.key AES-256 expects a key of 256 bit, 32 byte. To generate such a key, use: openssl rand 32 myaes.key – ingenue Oct 12 '17 at 11:57.
OpenSSL provides SSL, TLS and generalpurpose cryptography. It wraps the OpenSSL library.
OpenSSL comes bundled with the Standard Library of Ruby.
X.509 certificates are associated with a private/public key pair, typically a RSA, DSA or ECC key (see also OpenSSL::PKey::RSA, OpenSSL::PKey::DSA and OpenSSL::PKey::EC), the public key itself is stored within the certificate and can be accessed in form of an OpenSSL::PKey. Certificates are typically used to be able to associate some form of.
This means the OpenSSL extension is compiled with Ruby and packaged onbuild. During compile time, Ruby will need to link against the OpenSSLlibrary on your system. However, you cannot use openssl provided by Appleto build standard library openssl.
If you use OSX, you should install another openssl and run “`./configure–with-openssl-dir=/path/to/another-openssl“`. For Homebrew user, run `brewinstall openssl` and then “`./configure –with-openssl-dir=`brew –prefixopenssl` “`.
All examples assume you have loaded OpenSSL with:
These examples build atop each other. For example the key created in thenext is used in throughout these examples.
Keys
Creating a Key
This example creates a 2048 bit RSA keypair and writes it to the currentdirectory.
Exporting a Key
Keys saved to disk without encryption are not secure as anyone who getsahold of the key may use it unless it is encrypted. In order to securelyexport a key you may export it with a pass phrase.
OpenSSL::Cipher.ciphersreturns a list of available ciphers.
Loading a Key
A key can also be loaded from a file.
or
Loading an Encrypted Key
OpenSSL will prompt you for your pass phrase when loading an encrypted key.If you will not be able to type in the pass phrase you may provide it whenloading the key:
RSA Encryption
RSA provides encryption and decryption using the public and private keys.You can use a variety of padding methods depending upon the intended use ofencrypted data.
Encryption & Decryption
Asymmetric public/private key encryption is slow and victim to attack incases where it is used without padding or directly to encrypt larger chunksof data. Typical use cases for RSA encryption involve “wrapping” asymmetric key with the public key of the recipient who would “unwrap” thatsymmetric key again using their private key. The following illustrates asimplified example of such a key transport scheme. It shouldn’t be used inpractice, though, standardized protocols should always be preferred.
A symmetric key encrypted with the public key can only be decrypted withthe corresponding private key of the recipient.
By default PKCS#1 padding will be used, but it is also possible to useother forms of padding, see PKey::RSAfor further details.
Signatures
Using “private_encrypt” to encrypt some data with the private key isequivalent to applying a digital signature to the data. A verifying partymay validate the signature by comparing the result of decrypting thesignature with “public_decrypt” to the original data. However, OpenSSL::PKey already has methods “sign” and“verify” that handle digital signatures in a standardized way -“private_encrypt” and “public_decrypt” shouldn’t be used in practice.
To sign a document, a cryptographically secure hash of the document iscomputed first, which is then signed using the private key.
To validate the signature, again a hash of the document is computed and thesignature is decrypted using the public key. The result is then compared tothe hash just computed, if they are equal the signature was valid.
PBKDF2 Password-based Encryption
If supported by the underlying OpenSSL version used, Password-basedEncryption should use the features of PKCS5. If not supported or if required bylegacy applications, the older, less secure methods specified in RFC 2898are also supported (see below).
PKCS5 supports PBKDF2 as it was specifiedin PKCS#5 v2.0.It still uses a password, a salt, and additionally a number of iterationsthat will slow the key derivation process down. The slower this is, themore work it requires being able to brute-force the resulting key.
Encryption
The strategy is to first instantiate a Cipher for encryption, and then to generatea random IV plus a key derived from the password using PBKDF2. PKCS #5 v2.0recommends at least 8 bytes for the salt, the number of iterations largelydepends on the hardware being used.
Decryption
Use the same steps as before to derive the symmetric AES key, this timesetting the Cipher up for decryption.
PKCS #5 Password-based Encryption
PKCS #5 is a password-based encryption standard documented at RFC2898. It allows a shortpassword or passphrase to be used to create a secure encryption key. Ifpossible, PBKDF2 as described above should be used if the circumstancesallow it.
PKCS #5 uses a Cipher, a pass phrase anda salt to generate an encryption key.
Encryption
First set up the cipher for encryption
If you are using unique serial, which is not being used by anyone else it is actually exact the same as having a legit copy of Need for Speed Most Wanted. Why it is so importinat? Nfs most wanted origin key generator.
Then pass the data you want to encrypt through
Decryption
Use a new Cipher instance set up fordecryption
Then pass the data you want to decrypt through
X509 Certificates
Creating a Certificate
This example creates a self-signed certificate using an RSA key and a SHA1signature.
Certificate Extensions
You can add extensions to the certificate withOpenSSL::SSL::ExtensionFactory to indicate the purpose of the certificate.
The list of supported extensions (and in some cases their possible values)can be derived from the “objects.h” file in the OpenSSL source code.
Signing a Certificate
To sign a certificate set the issuer and use OpenSSL::X509::Certificate#signwith a digest algorithm. This creates a self-signed cert because we’reusing the same name and key to sign the certificate as was used to createthe certificate.
Loading a Certificate
Like a key, a cert can also be loaded from a file.
Verifying a Certificate
Certificate#verify will return true when a certificate was signed with thegiven public key.
Certificate Authority
A certificate authority (CA) is a trusted third party that allows you toverify the ownership of unknown certificates. The CA issues key signaturesthat indicate it trusts the user of that key. A user encountering the keycan verify the signature by using the CA’s public key.
CA Key
CA keys are valuable, so we encrypt and save it to disk and make sure it isnot readable by other users.
CA Certificate
A CA certificate is created the same way we created a certificate above,but with different extensions.
This extension indicates the CA’s key may be used as a CA.
This extension indicates the CA’s key may be used to verify signatures onboth certificates and certificate revocations.
Root CA certificates are self-signed.
The CA certificate is saved to disk so it may be distributed to all theusers of the keys this CA will sign.
Certificate Signing Request
The CA signs keys through a Certificate Signing Request (CSR). The CSRcontains the information necessary to identify the key.
A CSR is saved to disk and sent to the CA for signing.
Creating a Certificate from a CSR
Upon receiving a CSR the CA will verify it before signing it. A minimalverification would be to check the CSR’s signature.
After verification a certificate is created, marked for various usages,signed with the CA key and returned to the requester.
SSL and TLS Connections
Using our created key and certificate we can create an SSL or TLS connection. An SSLContext is used toset up an SSL session.
SSL Server
An SSL server requires the certificate andprivate key to communicate securely with its clients:
Then create an SSLServer with a TCP server socket and the context. Use theSSLServer like an ordinary TCP server.
SSL client
An SSL client is created with a TCP socketand the context. SSLSocket#connect must be called to initiate the SSL handshake and start encryption. A key andcertificate are not required for the client socket.
Peer Verification
An unverified SSL connection does notprovide much security. For enhanced security the client or server canverify the certificate of its peer.
The client can be modified to verify the server’s certificate against thecertificate authority’s certificate:
If the server certificate is invalid or context.ca_file is notset when verifying peers an OpenSSL::SSL::SSLError will be raised.
While Encrypting a File with a Password from the Command Line using OpenSSLis very useful in its own right, the real power of the OpenSSL library is itsability to support the use of public key cryptograph for encrypting orvalidating data in an unattended manner (where the password is not required toencrypt) is done with public keys.
The Commands to Run
Generate a 2048 bit RSA Key
You can generate a public and private RSA key pair like this:
openssl genrsa -des3 -out private.pem 2048
That generates a 2048-bit RSA key pair, encrypts them with a password you provideand writes them to a file. You need to next extract the public key file. You willuse this, for instance, on your web server to encrypt content so that it canonly be read with the private key.
Export the RSA Public Key to a File
This is a command that is
openssl rsa -in private.pem -outform PEM -pubout -out public.pem
The -pubout flag is really important. Be sure to include it.
Next open the public.pem and ensure that it starts with-----BEGIN PUBLIC KEY-----. This is how you know that this file is thepublic key of the pair and not a private key.
To check the file from the command line you can use the less command, like this:
less public.pem
Do Not Run This, it Exports the Private Key
A previous version of the post gave this example in error.
openssl rsa -in private.pem -out private_unencrypted.pem -outform PEM
The error is that the -pubout was dropped from the end of the command.That changes the meaning of the command from that of exporting the public keyto exporting the private key outside of its encrypted wrapper. Inspecting theoutput file, in this case private_unencrypted.pem clearly shows that the keyis a RSA private key as it starts with -----BEGIN RSA PRIVATE KEY-----.
Visually Inspect Your Key Files
It is important to visually inspect you private and public key files to makesure that they are what you expect. OpenSSL will clearly explain the nature ofthe key block with a -----BEGIN RSA PRIVATE KEY----- or -----BEGIN PUBLIC KEY-----.
You can use less to inspect each of your two files in turn:
less private.pemto verify that it starts with a-----BEGIN RSA PRIVATE KEY-----less public.pemto verify that it starts with a-----BEGIN PUBLIC KEY-----
The next section shows a full example of what each key file should look like.
The Generated Key Files
The generated files are base64-encoded encryption keys in plain text format.If you select a password for your private key, its file will be encrypted withyour password. Be sure to remember this password or the key pair becomes useless.
The private.pem file looks something like this:
The public key, public.pem, file looks like:
Protecting Your Keys
Depending on the nature of the information you will protect, it’s important tokeep the private key backed up and secret. The public key can be distributedanywhere or embedded in your web application scripts, such as in your PHP,Ruby, or other scripts. Again, backup your keys!
Remember, if the key goes away the data encrypted to it is gone. Keeping aprinted copy of the key material in a sealed envelope in a bank safety depositbox is a good way to protect important keys against loss due to fire or harddrive failure.
Openssl Create Crt And Key
Oh, and one last thing.
If you, dear reader, were planning any funny business with the private key that I have just published here. Know that they were made especially for this series of blog posts. I do not use them for anything else.
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