v1g1lance.netlify.app
Openssl Generate Public Key Fingerprint
# Generate PKCS#12 (P12) file for cert; combines both key and certificate together: openssl pkcs12 -export -inkey privatekey.pem -in certificate.pem -out cert.pfx # Generate SHA256 Fingerprint for Certificate and export to a file: openssl x509 -noout -fingerprint -sha256 -inform pem -in certificate.pem fingerprint.txt # Generate SHA1. You can get the key's fingerprint with the following OpenSSL command. If you're using Windows, you'll need to install Git Bash for Windows and run the command with that tool. Openssl rsa -pubout -outform DER -in /.oci/ociapikey.pem openssl md5 -c.
- Openssl Generate Public Key Fingerprint Test
- Openssl Public Key Fingerprint
- Generate Public Key Windows
- Openssl Rsa Key Pair
In public-key cryptography, a public key fingerprint is a short sequence of bytes used to identify a longer public key. Fingerprints are created by applying a cryptographic hash function to a public key. Since fingerprints are shorter than the keys they refer to, they can be used to simplify certain key management tasks. In Microsoft software, 'thumbprint' is used instead of 'fingerprint'.
Creating public key fingerprints[edit]
A public key fingerprint is typically created through the following steps:
- A public key (and optionally some additional data) is encoded into a sequence of bytes. To ensure that the same fingerprint can be recreated later, the encoding must be deterministic, and any additional data must be exchanged and stored alongside the public key. The additional data is typically information which anyone using the public key should be aware of. Examples of additional data include: which protocol versions the key should be used with (in the case of PGP fingerprints); and the name of the key holder (in the case of X.509 trust anchor fingerprints, where the additional data consists of an X.509 self-signed certificate).
- The data produced in the previous step is hashed with a cryptographic hash function such as SHA-1 or SHA-2.
- If desired, the hash function output can be truncated to provide a shorter, more convenient fingerprint.
This process produces a short fingerprint which can be used to authenticate a much larger public key. For example, whereas a typical RSA public key will be 1024 bits in length or longer, typical MD5 or SHA-1 fingerprints are only 128 or 160 bits in length.
When displayed for human inspection, fingerprints are usually encoded into hexadecimal strings. These strings are then formatted into groups of characters for readability. For example, a 128-bit MD5 fingerprint for SSH would be displayed as follows:
Using public key fingerprints for key authentication[edit]
When a public key is received over an untrusted channel, such as the Internet, the recipient often wishes to authenticate the public key. Fingerprints can help accomplish this, since their small size allows them to be passed over trusted channels where public keys won't easily fit.
For example, if Alice wishes to authenticate a public key as belonging to Bob, she can contact Bob over the phone or in person and ask him to read his fingerprint to her, or give her a scrap of paper with the fingerprint written down. Alice can then check that this trusted fingerprint matches the fingerprint of the public key. Exchanging and comparing values like this is much easier if the values are short fingerprints instead of long public keys.
Fingerprints can also be useful when automating the exchange or storage of key authentication data. For example, if key authentication data needs to be transmitted through a protocol or stored in a database where the size of a full public key is a problem, then exchanging or storing fingerprints may be a more viable solution.
In addition, fingerprints can be queried with search engines in order to ensure that the public key that a user just downloaded can be seen by third party search engines. If the search engine returns hits referencing the fingerprint linked to the proper site(s), one can feel more confident that the key is not being injected by an attacker, such as a Man-in-the-middle attack.
PGP developed the PGP word list to facilitate the exchange of public key fingerprints over voice channels.
Public key fingerprints in practice[edit]
In systems such as SSH, users can exchange and check fingerprints manually to perform key authentication. Once a user has accepted another user's fingerprint, that fingerprint (or the key it refers to) will be stored locally along with a record of the other user's name or address, so that future communications with that user can be automatically authenticated.
In systems such as X.509-based PKI, fingerprints are primarily used to authenticate root keys. These root keys issue certificates which can be used to authenticate user keys. This use of certificates eliminates the need for manual fingerprint verification between users.
In systems such as PGP or Groove, fingerprints can be used for either of the above approaches: they can be used to authenticate keys belonging to other users, or keys belonging to certificate-issuing authorities. In PGP, normal users can issue certificates to each other, forming a web of trust, and fingerprints are often used to assist in this process (e.g., at key-signing parties).
In systems such as CGA or SFS and most cryptographic peer-to-peer networks, fingerprints are embedded into pre-existing address and name formats (such as IPv6 addresses, file names or other identification strings). If addresses and names are already being exchanged through trusted channels, this approach allows fingerprints to piggyback on them.[1]
In PGP, most keys are created in such a way so that what is called the 'key ID' is equal to the lower 32 or 64 bits respectively of a key fingerprint. PGP uses key IDs to refer to public keys for a variety of purposes. These are not, properly speaking, fingerprints, since their short length prevents them from being able to securely authenticate a public key. 32bit key ids should not be used as current hardware can generate 32bit key id in just 4 seconds.[2]
Security of public key fingerprints[edit]
The primary threat to the security of a fingerprint is a preimage attack, where an attacker constructs a key pair whose public key hashes to a fingerprint that matches the victim's fingerprint. The attacker could then present his public key in place of the victim's public key to masquerade as the victim.
A secondary threat to some systems is a collision attack, where an attacker constructs multiple key pairs which hash to his own fingerprint. This may allow an attacker to repudiate signatures he has created, or cause other confusion.
To prevent preimage attacks, the cryptographic hash function used for a fingerprint should possess the property of second preimage resistance. If collision attacks are a threat, the hash function should also possess the property of collision-resistance. While it is acceptable to truncate hash function output for the sake of shorter, more usable fingerprints, the truncated fingerprints must be long enough to preserve the relevant properties of the hash function against brute-force search attacks.
In practice, most fingerprints commonly used today are based on non-truncated MD5 or SHA-1 hashes. As of 2017, collisions but not preimages can be found in MD5 and SHA-1. The future is therefore likely to bring increasing use of newer hash functions such as SHA-256. However, fingerprints based on SHA-256 and other hash functions with long output lengths are more likely to be truncated than (relatively short) MD5 or SHA-1 fingerprints.
In situations where fingerprint length must be minimized at all costs, the fingerprint security can be boosted by increasing the cost of calculating the fingerprint. For example, in the context of Cryptographically Generated Addresses, this is called 'Hash Extension' and requires anyone calculating a fingerprint to search for a hashsum starting with a fixed number of zeroes[3], which is assumed to be an expensive operation.
See also[edit]
References[edit]
- ^David Mazières; M. Frans Kaashoek (September 1998). Escaping the Evils of Centralized Control with self-certifying pathnames(PostScript). Proceedings of the 8th ACM SIGOPS European workshop: Support for composing distributed applications. Sintra, Portugal: MIT. Retrieved 2006-12-23.
- ^Evil 32: Check Your GPG Fingerprints
- ^Aura, Tumas (March 2005). 'Hash Extension'. Cryptographically Generated Addresses (CGA). IETF. sec. 7.2. doi:10.17487/RFC3972. RFC 3972. Retrieved January 2, 2018.
The openssl program provides a rich variety of commands, each of which often has a wealth of options and arguments. Many commands use an external configuration file for some or all of their arguments and have a -config
option to specify that file. The environment variable OPENSSL_CONF can be used to specify the location of the configuration file. If the environment variable is not specified, a default file is created in the default certificate storage area called openssl.cnf. The settings in this default configuration file depend on the flags set when the version of OpenSSL being used was built.
This article is an overview of the available tools provided by openssl. For all of the details on usage and implementation, you can find the manpages which are automatically generated from the source code at the official OpenSSL project home. Likewise, the source code itself may be found on the OpenSSL project home page, as well as on the OpenSSL Github. The main OpenSSL site also includes an overview of the command-line utilities, as well as links to all of their respective documentation.
- 2Basic Tasks
- 2.5Generating Keys Based on Elliptic Curves
- 2.5.1Generating the Curve Parameters
- 2.5Generating Keys Based on Elliptic Curves
- 3Commands
The entry point for the OpenSSL library is the openssl binary, usually /usr/bin/openssl on Linux. The general syntax for calling openssl is as follows:
Alternatively, you can call openssl without arguments to enter the interactive mode prompt. You may then enter commands directly, exiting with either a quit
command or by issuing a termination signal with either Ctrl+C or Ctrl+D. The following is a sample interactive session in which the user invokes the prime command twice before using the quit command to terminate the session.
This section is a brief tutorial on performing the most basic tasks using OpenSSL. For a detailed explanation of the rationale behind the syntax and semantics of the commands shown here, see the section on Commands.
Getting Help[edit]
As mentioned previously, the general syntax of a command is openssl command [ command_options ] [ command_arguments ]
. The help command is no different, but it does have its idiosyncrasies. To view the top-level help menu, you can call openssl as follows.
This query will print all of the available commands, like so:
Note the above output was truncated, so only the first four lines of output are shown.
A help menu for each command may be requested in two different ways. First, the same command used above may be repeated, followed by the name of the command to print help for.
The program will then display the valid options for the given command.
The second way of requesting the help menu for a particular command is by using the first option in the output shown above, namely openssl command -help
. Both commands will yield the same output; the help menu displayed will be exactly the same.
For additional information on the usage of a particular command, the project manpages are a great source of information. Another excellent source of information is the project perldocs. perldoc is a utility included with most if not all Perl distributions, and it's capable of displaying documentation information in a variety of formats, one of which is as manpages. Not surprisingly, the project documentation is generated from the pod files located in the doc directory of the source code.
Getting Library Version Information[edit]
Avg pc tuneup 2015 key generator. As mentioned above, the version command's help menu may be queried for additional options like so:
If a product key works, That’s great, But if it doesn’t just skip it and copy another Windows 7 Home premium Serial key from the list below and test that one. Key generator for windows 7 home basic.
Using the -a option to show all version information yields the following output on my current machine:
Generating an RSA Private Key[edit]
Generating a private key can be done in a variety of different ways depending on the type of key, algorithm, bits, and other options your specific use case may require. In this example, we are generating a private key using RSA and a key size of 2048 bits.
To generate a password protected private key, the previous command may be slightly amended as follows:
The addition of the -aes256 option specifies the cipher to use to encrypt the private key file. For a list of available ciphers in the library, you can run the following command:
With your private key in hand, you can use the following command to see the key's details, such as its modulus and its constituent primes. Remember to change the name of the input file to the file name of your private key.
The above command yields the following output in my specific case. Your output will differ but should be structurally similar.
Keep in mind the above key was generated solely for pedagogical purposes; never give anyone access to your private keys.
Generating a Public Key[edit]
Having previously generated your private key, you may generate the corresponding public key using the following command.
You may once again view the key details, using a slightly different command this time.
The output for the public key will be shorter, as it carries much less information, and it will look something like this.
For more information on generating keys, see the source code documentation, located in the doc/HOWTO/keys.txt file.
Generating Keys Based on Elliptic Curves[edit]
There are essentially two steps to generating a key:
- Generate the parameters for the specific curve you are using
- Use those parameters to generate the key
To see the list of curves instrinsically supported by openssl, you can use the -list_curves</t> option when calling the <tt>ecparam command.
![Number Number](https://blogs.sap.com/wp-content/uploads/2015/07/openssl_sha1_fingerprint_754663.jpg)
For this example I will use the prime256v1 curve, which is an X9.62/SECG curve over a 256 bit prime field.
Generating the Curve Parameters[edit]
Having selected our curve, we now call ecparam to generate our parameters file.
Printing Parameters to Standard Out[edit]
You can print the generated curve parameters to the terminal output with the following command:
Printing Parameters as C Code[edit]
Analogously, you may also output the generated curve parameters as C code. The parameters can then be loaded by calling the get_ec_group_XXX() function. To print the C code to the current terminal's output, the following command may be used:
And here are the first few lines of the corresponding output:
Generating the Key[edit]
With the curve parameters in hand, we are now free to generate the key. Just as with the [#Generating an RSA Private Key RSA] example above, we may optionally specify a cipher algorithm with which to encrypt the private key. The call to generate the key using the elliptic curve parameters generated in the example above looks like this:
![Openssl Generate Public Key Fingerprint Openssl Generate Public Key Fingerprint](https://undrophome.files.wordpress.com/2019/04/screen-shot-2019-04-01-at-11.23.15-am.png?w=1024&h=512)
Putting it All Together[edit]
The process of generation a curve based on elliptic-curves can be streamlined by calling the genpkey command directly and specifying both the algorithm and the name of the curve to use for parameter generation. In it's simplest form, the command to generate a key based on the same curve as in the example above looks like this:
This command will result in the generated key being printed to the terminal's output.
Remember that you can specify a cipher algorithm to encrypt the key with, which something you may or may not want to do, depending on your specific use case. Here is a slightly more complete example showing a key generated with a password and written to a specific output file.
Just as with the previous example, you can use the pkey command to inspect your newly-generated key.
For more details on elliptic curve cryptography or key generation, check out the manpages.
Base64 Encoding Strings[edit]
Openssl Generate Public Key Fingerprint Test
For simple string encoding, you can use 'here string' syntax with the base64 command as below. Intuitively, the -e flag specifies the action to be encoding.
Similarly, the base64 command's -d flag may be used to indicate decoding mode.
Generating a File Hash[edit]
One of the most basic uses of the dgst command (short for digest) is viewing the hash of a given file. To do this, simply invoke the command with the specified digest algorithm to use. For this example, I will be hashing an arbitrary file on my system using the MD5, SHA1, and SHA384 algorithms.
Openssl Public Key Fingerprint
For a list of the available digest algorithms, you can use the following command.
You can also use a similar command to see the available digest commands:
Below are three sample invocations of the md5, sha1, and sha384 digest commands using the same file as the dgst command invocation above.
File Encryption and Decryption[edit]
The following example demonstrates a simple file encryption and decryption using the enc command. The first argument is the cipher algorithm to use for encrypting the file. For this example I carefully selected the AES-256 algorithm in CBC Mode by looking up the available ciphers and picking out the first one I saw. To see the list of available ciphers, you can use the following command.
You can also use the following command:
Having selected an encryption algorithm, you must then specify whether the action you are taking is either encryption or decryption via the -e or -d flags, respectively. The -iter flag specifies the number of iterations on the password used for deriving the encryption key. A higher iteration count increases the time required to brute-force the resulting file. Using this option implies enabling use of the Password-Based Key Derivation Function 2, usually set using the -pbkdf2 flag. We then use the -salt flag to enable the use of a randomly generated salt in the key-derivation function.
Putting it all together, you can see the command to encrypt a file and the corresponding output below. Note that the passwords entered by the user are blank, just as they would usually be in a terminal session.
The analogous decryption command is as follows:
Generate Public Key Windows
There are three different kinds of commands. These are standard commands, cipher commands, and digest commands. Calling the OpenSSL top-level help command with no arguments will result in openssl printing all available commands by group, sorted alphabetically.
Standard Commands[edit]
Command | Description |
---|---|
asn1parse | Parse an ASN.1 sequence. |
ca | Certificate Authority (CA) Management. |
ciphers | Cipher Suite Description Determination. |
cms | CMS (Cryptographic Message Syntax) utility. |
crl | Certificate Revocation List (CRL) Management. |
crl2pkcs7 | CRL to PKCS#7 Conversion. |
dgst | Message Digest calculation. MAC calculations are superseded by mac(1). |
dhparam | Generation and Management of Diffie-Hellman Parameters. Superseded by genpkey(1) and pkeyparam(1). |
dsa | DSA Data Management. |
dsaparam | DSA Parameter Generation and Management. Superseded by genpkey(1) and pkeyparam(1). |
ec | EC (Elliptic curve) key processing. |
ecparam | EC parameter manipulation and generation. |
enc | Encoding with Ciphers. |
engine | Engine (loadable module) information and manipulation. |
errstr | Error Number to Error String Conversion. |
gendsa | Generation of DSA Private Key from Parameters. Superseded by genpkey(1) and pkey(1). |
genpkey | Generation of Private Key or Parameters. |
genrsa | Generation of RSA Private Key. Superseded by genpkey(1). |
info | Display diverse information built into the OpenSSL libraries. |
kdf | Key Derivation Functions. |
mac | Message Authentication Code Calculation. |
nseq | Create or examine a Netscape certificate sequence. |
ocsp | Online Certificate Status Protocol utility. |
passwd | Generation of hashed passwords. |
pkcs12 | PKCS#12 Data Management. |
pkcs7 | PKCS#7 Data Management. |
pkcs8 | PKCS#8 format private key conversion tool. |
pkey | Public and private key management. |
pkeyparam | Public key algorithm parameter management. |
pkeyutl | Public key algorithm cryptographic operation utility. |
prime | Compute prime numbers. |
rand | Generate pseudo-random bytes. |
rehash | Create symbolic links to certificate and CRL files named by the hash values. |
req | PKCS#10 X.509 Certificate Signing Request (CSR) Management. |
rsa | RSA key management. |
rsautl | RSA utility for signing, verification, encryption, and decryption. Superseded by pkeyutl(1). |
s_client | This implements a generic SSL/TLS client which can establish a transparent connection to a remote server speaking SSL/TLS. |
s_server | This implements a generic SSL/TLS server which accepts connections from remote clients speaking SSL/TLS. |
s_time | SSL Connection Timer. |
sess_id | SSL Session Data Management. |
smime | S/MIME mail processing. |
speed | Algorithm Speed Measurement. |
spkac | SPKAC printing and generating utility. |
srp | Maintain SRP password file. |
storeutl | Utility to list and display certificates, keys, CRLs, etc. |
ts | Time Stamping Authority tool (client/server). |
verify | X.509 Certificate Verification. |
version | OpenSSL Version Information. |
x509 | X.509 Certificate Data Management. |
Openssl Rsa Key Pair
- Paul Heinlein. 'OpenSSL Command-Line HOWTO'. Has many quick cookbook-style recipes for doing common tasks using the 'oppenssl' command-line application.