How to Compute a Digest of a File

Language:

When you compute a digest of a file, you can check to see that the file has not been tampered with by comparing digest outputs. A digest does not alter the original file.

List the available digest algorithms.
```
$ digest -l
sha1
md5
sha224
sha256
sha384
sha512
```
Note - Whenever possible, select a FIPS 140-2 approved algorithm. See FIPS 140-2 Algorithms in the Cryptographic Framework in Using a FIPS 140-2 Enabled System in Oracle Solaris 11.3.
Compute the digest of the file and save the digest listing.
Provide an algorithm with the digest command.
```
$ digest -v -a algorithm input-file > digest-listing
```
–v
Displays the output in the following format:
```
algorithm (input-file) = digest
```
–a algorithm

The algorithm to use to compute a digest of the file. Type the algorithm as the algorithm appears in the output of Step 1.

Note - Whenever possible, select a FIPS 140-2 approved algorithm. See FIPS 140-2 Algorithms in the Cryptographic Framework in Using a FIPS 140-2 Enabled System in Oracle Solaris 11.3.

input-file

The input file for the digest command.

digest-listing

The output file for the digest command.

Example 6 Computing a Digest With the SHA1 Mechanism

In the following example, the digest command uses the SHA1 mechanism to provide a directory listing. The results are placed in a file.

$ digest -v -a sha512 docs/* > $HOME/digest.docs.legal.05.07
$ more ~/digest.docs.legal.05.07
sha512 (docs/legal1) = a269d...c618e1bf19b3d5c9f835242708eb2b572d7b
sha512 (docs/legal2) = 57be3...59a7168564296c142715cc9ed979dd838a7b
sha512 (docs/legal3) = ed31d...0fb3b80d4cd58327bcc29b2e7b90a0af6770
sha512 (docs/legal4) = 67ce1...0ba0c55695614329110d0686bc2773630b5f