Content-type: text/html Man page of encrypt


Section: User Commands (1)
Updated: 20 Jan 2006
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encrypt, decrypt - encrypt or decrypt files  


/usr/bin/encrypt -l | -a algorithm [-v] [-k key_file] [-i input_file] [-o output_file]

/usr/bin/decrypt -l | -a algorithm [-v] [-k key_file] [-i input_file] [-o output_file]  


This utility encrypts or decrypts the given file or stdin using the algorithm specified. If no output file is specified, output is to standard out. If input and output are the same file, the encrypted output is written to a temporary work file in the same filesystem and then used to replace the original file.

On decryption, if the input and output are the same file, the cleartext replaces the ciphertext file.

The output file of encrypt and the input file for decrypt contains the following information:

• Output format version number, 4 bytes in network byte order. The current version is 1.

• Iterations used in key generation function, 4 bytes in network byte order.

• IV (ivlen bytes)[1]. iv data is generated by random bytes equal to one block size.

• Salt data used in key generation (16 bytes).

• Cipher text data.



The following options are supported:

-a algorithm Specify the name of the algorithm to use during the encryption or decryption process. See USAGE, Algorithms for details.

-i input_file Specify the input file. Default is stdin if input_file is not specified.

-k key_file Specify the file containing the key value for the encryption algorithm. Each algorithm has specific key material requirements, as stated in the PKCS#11 specification. If -k is not specified, encrypt prompts for key material using getpassphrase(3C).

For information on generating a key file, see dd(1M) or System Administration Guide: Security Services.

-l Display the list of algorithms available on the system. This list can change depending on the configuration of the cryptographic framework. The keysizes are displayed in bits.

-o output_file Specify output file. Default is stdout if output_file is not specified. If stdout is used without redirecting to a file, the terminal window can appear to hang because the raw encrypted or decrypted data has disrupted the terminal emulation, much like viewing a binary file can do at times.

-v Display verbose information. See Verbose.





The supported algorithms are displayed with their minimum and maximum key sizes in the -l option. These algorithms are provided by the cryptographic framework. Each supported algorithm is an alias of the PKCS #11 mechanism that is the most commonly used and least restricted version of a particular algorithm type. For example: des is an alias to CKM_DES_CBC_PAD and arcfour is an alias to CKM_RC4. Algorithm variants with no padding or ECB are not supported.

These aliases are used with the -a option and are case-sensitive.  


When the -k option is not used during encryption and decryption tasks, the user is prompted for a passphrase. The passphrase is manipulated into a more secure key using the PBKDF2 algorithm specified in PKCS #5.

When a passphrase is used with encrypt and decrypt, the user entered passphrase is turned into an encryption key using the PBKDF2 algorithm as defined defined in, PKCS #5 v2.0.  


If an input file is provided to the command, a progress bar spans the screen. The progress bar denotes every 25% completed with a pipe sign (|). If the input is from standard input, a period (.) is displayed each time 40KB is read. Upon completion of both input methods, Done is printed.  


Example 1: Listing Available Algorithms

The following example lists available algorithms:

example$ encrypt -l
Algorithm       Keysize:  Min   Max
aes                       128   128
arcfour                     8   128
des                        64    64
3des                      192   192

Example 2: Encrypting Using AES

The following example encrypts using AES and prompts for the encryption key:

example$ encrypt -a aes -i myfile.txt -o secretstuff

Example 3: Using an In Pipe to Provide Encrypted Tape Backup

The following example uses an in pipe to provide encrypted tape backup:

example$ ufsdump 0f - /var | encrypt -a arcfour \
    -k /etc/mykeys/backup.k | dd of=/dev/rmt/0

Example 4: Using an In Pipe to Restore Tape Backup

The following example uses and in pipe to restore a tape backup:

example$ decrypt -a arcfour -k /etc/mykeys/backup.k \
    -i /dev/rmt/0 | ufsrestore xvf -

Example 5: Encrypting an Input File Using the 3DES Algorithm

The following example encrypts the inputfile file with the 192-bit key stored in the des3key file:

example$ encrypt -a 3des -k des3key -i inputfile -o outputfile


The following exit values are returned:

0 Successful completion.

>0 An error occurred.



See attributes(5) for descriptions of the following attributes:

Interface StabilityEvolving



digest(1), mac(1), dd(1M), getpassphrase(3C), libpkcs11(3LIB), attributes(5), pkcs11_softtoken(5)

System Administration Guide: Security Services

RSA PKCS#11 v2.11:

RSA PKCS#5 v2.0:




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Time: 02:39:22 GMT, October 02, 2010