OpenSSL-Version : 1.0.2kDESCRIPTION
OpenSSL is a cryptography toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) network protocols and related cryptography standards required by them.
The openssl program is a command line tool for using the various cryptography functions of OpenSSL's crypto library from the shell. It can be used for
o Creation and management of private keys, public keys and parameters
o Public key cryptographic operations
o Creation of X.509 certificates, CSRs and CRLs
o Calculation of Message Digests
o Encryption and Decryption with Ciphers
o SSL/TLS Client and Server Tests
o Handling of S/MIME signed or encrypted mail
o Time Stamp requests, generation and verificationOpenSSL介紹
OpenSSL是一個加密工具包，實現了安全套接字層(SSL v2/ v3)和傳輸層安全(TLS v1)網絡協議以及它們所要求的相關密碼學標準。
openssl程序是一個命令行工具，用於從shell中使用openssl的crypto庫的各種密碼學功能。它可以被用來做
OpenSSL是一個安全工具集，同時也提供了開源程序庫。它支持ssl(Secure Sockets Layer, v2/v3)，TLS(Transport Layer Secure, v1)。這套工具集的應用範圍非常之廣，包括：
創建和管理私鑰、公鑰。
公鑰加密操作。
創建X.509證書（Certificate），證書請求（CSR），證書撤銷（CRL）。
計算消息摘要（MD5, SHA-1等）。
使用密碼加解密（Encryption/Decryption with Ciphers）。
SSL/TLS 客戶端/服務器測試。
處理S/MIME簽名以及加密郵件。# openssl --help
openssl:Error: '--help' is an invalid command.
Standard commands
asn1parse ca ciphers cms
crl crl2pkcs7 dgst dh
dhparam dsa dsaparam ec
ecparam enc engine errstr
gendh gendsa genpkey genrsa
nseq ocsp passwd pkcs12
pkcs7 pkcs8 pkey pkeyparam
pkeyutl prime rand req
rsa rsautl s_client s_server
s_time sess_id smime speed
spkac ts verify version
x509
Message Digest commands (see the `dgst' command for more details)
md2 md4 md5 rmd160
sha sha1
Cipher commands (see the `enc' command for more details)
aes-128-cbc aes-128-ecb aes-192-cbc aes-192-ecb
aes-256-cbc aes-256-ecb base64 bf
bf-cbc bf-cfb bf-ecb bf-ofb
camellia-128-cbc camellia-128-ecb camellia-192-cbc camellia-192-ecb
camellia-256-cbc camellia-256-ecb cast cast-cbc
cast5-cbc cast5-cfb cast5-ecb cast5-ofb
des des-cbc des-cfb des-ecb
des-ede des-ede-cbc des-ede-cfb des-ede-ofb
des-ede3 des-ede3-cbc des-ede3-cfb des-ede3-ofb
des-ofb des3 desx idea
idea-cbc idea-cfb idea-ecb idea-ofb
rc2 rc2-40-cbc rc2-64-cbc rc2-cbc
rc2-cfb rc2-ecb rc2-ofb rc4
rc4-40 rc5 rc5-cbc rc5-cfb
rc5-ecb rc5-ofb seed seed-cbc
seed-cfb seed-ecb seed-ofb zlibSYNOPSIS
openssl command [ command_opts ] [ command_args ]
openssl [ list-standard-commands | list-message-digest-commands | list-cipher-commands ]openssl list-standard-commands(標準命令)