Use the openssl dgst command and utility to output the hash of a given file. The output will be in hexadecimal, and the default hash function is sha256, although this can be overridden. md5 and sha1 are both common digest functions that are still routinely found in practice and can be specified in … [Read more...] about openssl dgst
openssl rsa
The openssl rsa command and utility is used to manage and process RSA keys. Use this command to encrypt decrypt, convert between forms of keys and print contents of the RSA keys. Generate an RSA key with openssl See our posts on generating an RSA key with both genpkey and genrsa. genpkey is … [Read more...] about openssl rsa
openssl ciphers
The openssl ciphers utility is a tool that will display, list, and check supported ciphers. It can test your environment to help you decide which cipher list is appropriate for your setup. openssl ciphers list To display a verbose listing of all ciphers, run the following command: openssl … [Read more...] about openssl ciphers
openssl genpkey
The openssl genpkey command is a utility for generating asymmetric private keys. openssl genpkey or genrsa The openssl genpkey utility has superseded the genrsa utility. While the genrsa is still valid and in use today, it is recommended to start using genpkey. genpkey gives you more than just … [Read more...] about openssl genpkey
openssl view certificate
To view and parse a certificate with openssl, run the following command with the openssl x509 utility: openssl x509 -in example.com.crt -text -noout Where x509 is a certificate utility, -in example.com.crt is the certificate to view, -text means to print the full details of the certificate in … [Read more...] about openssl view certificate
openssl smime
The openssl smime utility is useful for signing and encrypting S/MIME messages. S/MIME messages can be signed by multiple signers, be encrypted, decrypted, and verified. You can purchase an S/MIME email (user) certificate from almost any public CA (Certification Authority). For this exercise, we … [Read more...] about openssl smime
openssl encrypt a file
How to use openssl to encrypt a file with an asymmetric public key: Use the -rsautl option in openssl to encrypt a file using the RSA algorithm asymmetrically. When sharing a secret is not possible or less than ideal, asymmetric encryption is your best solution. First, if you do not already … [Read more...] about openssl encrypt a file
openssl-speed
The openssl-speed utility can be used to measure the efficiency of cryptographic hash algorithms. For this purposes of this exercise, no additional flags or switches were added to the command. Strictly running openssl-speed will attempt a speed test on each supported hash algorithm and output the … [Read more...] about openssl-speed