Which command can display the date information from a certificate?

Which command can display the date information from a certificate?

• A. openssl dgst -ripemd160 -c dexter
• B. openssl rsa -in dexter.key.secure -out dexter.key
• C. openssl x509 -noout -in dexter.crt -issuer -subject -dates
• D. openssl genrsa -des3 -out dexter.key 1024

Answer: (C)

The command that can display the date information from a certificate is the one that invokes `openssl x509`, which specifically allows for parsing and examining X.509 certificates. By using the flags `-noout`, `-in`, `-issuer`, `-subject`, and `-dates`, this command effectively extracts and shows details only about the issuer, subject, and associated date information without outputting the entire certificate content. In this context, the `-dates` flag is particularly relevant because it instructs the command to display the validity period of the certificate, typically comprising the 'not before' and 'not after' dates, which indicate the time frame during which the certificate is considered valid. Other options, while related to the OpenSSL tool, serve different purposes. For instance, commands involving `openssl dgst` relate to computing digests (hashes) of files, while those using `openssl rsa` and `openssl genrsa` are focused on RSA key management and generation instead of certificate examination. Therefore, option C stands out as the correct choice for displaying date information from a certificate.

The command that can display the date information from a certificate is the one that invokes openssl x509, which specifically allows for parsing and examining X.509 certificates. By using the flags -noout, -in, -issuer, -subject, and -dates, this command effectively extracts and shows details only about the issuer, subject, and associated date information without outputting the entire certificate content.

In this context, the -dates flag is particularly relevant because it instructs the command to display the validity period of the certificate, typically comprising the 'not before' and 'not after' dates, which indicate the time frame during which the certificate is considered valid.

Other options, while related to the OpenSSL tool, serve different purposes. For instance, commands involving openssl dgst relate to computing digests (hashes) of files, while those using openssl rsa and openssl genrsa are focused on RSA key management and generation instead of certificate examination. Therefore, option C stands out as the correct choice for displaying date information from a certificate.