GnuPG 安裝

1. 以 yum 安裝。

   [root@kvm8 ~]# yum install gnupg2
   Loaded plugins: fastestmirror
   Loading mirror speeds from cached hostfile
   dywang                                                   | 1.9 kB     00:00     
   Setting up Install Process
   Package gnupg2-2.0.14-4.el6.x86_64 already installed and latest version
   Nothing to do
   

2. 以 --help 選項列出輔助說明。

   [root@kvm8 ~]# gpg --help
   gpg (GnuPG) 2.0.14
   libgcrypt 1.4.5
   Copyright (C) 2009 Free Software Foundation, Inc.
   License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
   This is free software: you are free to change and redistribute it.
   There is NO WARRANTY, to the extent permitted by law.
   
   Home: ~/.gnupg
   Supported algorithms:
   Pubkey: RSA, ELG, DSA
   Cipher: 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH, CAMELLIA128, 
           CAMELLIA192, CAMELLIA256
   Hash: MD5, SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
   Compression: Uncompressed, ZIP, ZLIB, BZIP2
   
   Syntax: gpg [options] [files]
   sign, check, encrypt or decrypt
   default operation depends on the input data
   
   Commands:
    
    -s, --sign                 make a signature
        --clearsign            make a clear text signature
    -b, --detach-sign          make a detached signature
    -e, --encrypt              encrypt data
    -c, --symmetric            encryption only with symmetric cipher
    -d, --decrypt              decrypt data (default)
        --verify               verify a signature
    -k, --list-keys            list keys
        --list-sigs            list keys and signatures
        --check-sigs           list and check key signatures
        --fingerprint          list keys and fingerprints
    -K, --list-secret-keys     list secret keys
        --gen-key              generate a new key pair
        --delete-keys          remove keys from the public keyring
        --delete-secret-keys   remove keys from the secret keyring
        --sign-key             sign a key
        --lsign-key            sign a key locally
        --edit-key             sign or edit a key
        --gen-revoke           generate a revocation certificate
        --export               export keys
        --send-keys            export keys to a key server
        --recv-keys            import keys from a key server
        --search-keys          search for keys on a key server
        --refresh-keys         update all keys from a keyserver
        --import               import/merge keys
        --card-status          print the card status
        --card-edit            change data on a card
        --change-pin           change a card's PIN
        --update-trustdb       update the trust database
        --print-md             print message digests
        --server               run in server mode
   
   Options:
    
    -a, --armor                create ascii armored output
    -r, --recipient USER-ID    encrypt for USER-ID
    -u, --local-user USER-ID   use USER-ID to sign or decrypt
    -z N                       set compress level to N (0 disables)
        --textmode             use canonical text mode
    -o, --output FILE          write output to FILE
    -v, --verbose              verbose
    -n, --dry-run              do not make any changes
    -i, --interactive          prompt before overwriting
        --openpgp              use strict OpenPGP behavior
   
   (See the man page for a complete listing of all commands and options)
   
   Examples:
   
    -se -r Bob [file]          sign and encrypt for user Bob
    --clearsign [file]         make a clear text signature
    --detach-sign [file]       make a detached signature
    --list-keys [names]        show keys
    --fingerprint [names]      show fingerprints
   
   Please report bugs to <http://bugs.gnupg.org>.
   

3. 以 yum 安裝 rng-tools。

   [root@kvm8 ~]# yum install rng-tools
   

4. Kernel device used for random number input (default: /dev/hwrandom)

   [root@kvm8 ~]# rngd -r /dev/urandom