node.JS的加密模块crypto提供了 HTTP 或 HTTPS 连接过程中封装安全凭证的方法。也提供了 OpenSSL 的哈希，hmac, 加密（cipher）, 解密（decipher）, 签名（sign） 和 验证（verify） 方法的封装
crypto模块使用方法crypto.setEngine(engine[, flags])
为某些/所有 OpenSSL 函数加载并设置引擎（根据参数 flags 来设置）。
engine 可能是 id，或者是指向引擎共享库的路径。
flags是可选参数，默认值是ENGINE_METHOD_ALL ，可以是以下一个或多个参数的组合(在constants里定义)
ENGINE_METHOD_RSA
ENGINE_METHOD_DSA
ENGINE_METHOD_DH
ENGINE_METHOD_RAND
ENGINE_METHOD_ECDH
ENGINE_METHOD_ECDSA
ENGINE_METHOD_CIPHERS
ENGINE_METHOD_DIGESTS
ENGINE_METHOD_STORE
ENGINE_METHOD_PKEY_METH
ENGINE_METHOD_PKEY_ASN1_METH
ENGINE_METHOD_ALL
ENGINE_METHOD_NONE
crypto.getCiphers()返回支持的加密算法名数组
var crypto = require('crypto'); console.log(crypto.getCiphers()); //[ 'aes-128-cbc', 'aes-128-ccm', 'aes-128-cfb', 'aes-128-cfb1', 'aes-128-cfb8', 'aes-128-ctr', 'aes-128-ecb', 'aes-128-gcm', 'aes-128-ofb', 'aes-128-xts', 'aes-192-cbc', 'aes-192-ccm', 'aes-192-cfb', 'aes-192-cfb1', 'aes-192-cfb8', 'aes-192-ctr', 'aes-192-ecb', 'aes-192-gcm', 'aes-192-ofb', 'aes-256-cbc', 'aes-256-ccm', 'aes-256-cfb', 'aes-256-cfb1', 'aes-256-cfb8', 'aes-256-ctr', 'aes-256-ecb', 'aes-256-gcm', 'aes-256-ofb', 'aes-256-xts', 'aes128', 'aes192', 'aes256', 'bf', 'bf-cbc', 'bf-cfb', 'bf-ecb', 'bf-ofb', 'blowfish', 'camellia-128-cbc', 'camellia-128-cfb', 'camellia-128-cfb1', 'camellia-128-cfb8', 'camellia-128-ecb', 'camellia-128-ofb', 'camellia-192-cbc', 'camellia-192-cfb', 'camellia-192-cfb1', 'camellia-192-cfb8', 'camellia-192-ecb', 'camellia-192-ofb', 'camellia-256-cbc', 'camellia-256-cfb', 'camellia-256-cfb1', 'camellia-256-cfb8', 'camellia-256-ecb', 'camellia-256-ofb', 'camellia128', 'camellia192', 'camellia256', 'cast', 'cast-cbc', 'cast5-cbc', 'cast5-cfb', 'cast5-ecb', 'cast5-ofb', 'des', 'des-cbc', 'des-cfb', 'des-cfb1', 'des-cfb8', 'des-ecb', 'des-ede', 'des-ede-cbc', 'des-ede-cfb', 'des-ede-ofb', 'des-ede3', 'des-ede3-cbc', 'des-ede3-cfb', 'des-ede3-cfb1', 'des-ede3-cfb8', 'des-ede3-ofb', 'des-ofb', 'des3', 'desx', 'desx-cbc', 'id-aes128-CCM', 'id-aes128-GCM', 'id-aes128-wrap', 'id-aes192-CCM', 'id-aes192-GCM', 'id-aes192-wrap', 'id-aes256-CCM', 'id-aes256-GCM', 'id-aes256-wrap', 'id-smime-alg-CMS3DESwrap', 'idea', 'idea-cbc', 'idea-cfb', 'idea-ecb', 'idea-ofb', ... 15 more items ]
crypto.getCiphers()返回支持的哈希算法名数组。
var crypto = require('crypto'); console.log(crypto.getHashes()); //[ 'DSA', 'DSA-SHA', 'DSA-SHA1', 'DSA-SHA1-old', 'RSA-MD4', 'RSA-MD5', 'RSA-MDC2', 'RSA-RIPEMD160', 'RSA-SHA', 'RSA-SHA1', 'RSA-SHA1-2', 'RSA-SHA224', 'RSA-SHA256', 'RSA-SHA384', 'RSA-SHA512', 'dsaEncryption', 'dsaWithSHA', 'dsaWithSHA1', 'dss1', 'ecdsa-with-SHA1', 'md4', 'md4WithRSAEncryption', 'md5', 'md5WithRSAEncryption', 'mdc2', 'mdc2WithRSA', 'ripemd', 'ripemd160', 'ripemd160WithRSA', 'rmd160', 'sha', 'sha1', 'sha1WithRSAEncryption', 'sha224', 'sha224WithRSAEncryption', 'sha256', 'sha256WithRSAEncryption', 'sha384', 'sha384WithRSAEncryption', 'sha512', 'sha512WithRSAEncryption', 'shaWithRSAEncryption', 'ssl2-md5', 'ssl3-md5', 'ssl3-sha1', 'whirlpool' ]
crypto.getCurves()返回支持的椭圆曲线名数组。
var crypto = require('crypto'); console.log(crypto.getCurves()); //[ 'Oakley-EC2N-3', 'Oakley-EC2N-4', 'brainpoolP160r1', 'brainpoolP160t1', 'brainpoolP192r1', 'brainpoolP192t1', 'brainpoolP224r1', 'brainpoolP224t1', 'brainpoolP256r1', 'brainpoolP256t1', 'brainpoolP320r1', 'brainpoolP320t1', 'brainpoolP384r1', 'brainpoolP384t1', 'brainpoolP512r1', 'brainpoolP512t1', 'c2pnb163v1', 'c2pnb163v2', 'c2pnb163v3', 'c2pnb176v1', 'c2pnb208w1', 'c2pnb272w1', 'c2pnb304w1', 'c2pnb368w1', 'c2tnb191v1', 'c2tnb191v2', 'c2tnb191v3', 'c2tnb239v1', 'c2tnb239v2', 'c2tnb239v3', 'c2tnb359v1', 'c2tnb431r1', 'prime192v1', 'prime192v2', 'prime192v3', 'prime239v1', 'prime239v2', 'prime239v3', 'prime256v1', 'secp112r1', 'secp112r2', 'secp128r1', 'secp128r2', 'secp160k1', 'secp160r1', 'secp160r2', 'secp192k1', 'secp224k1', 'secp224r1', 'secp256k1', 'secp384r1', 'secp521r1', 'sect113r1', 'sect113r2', 'sect131r1', 'sect131r2', 'sect163k1', 'sect163r1', 'sect163r2', 'sect193r1', 'sect193r2', 'sect233k1', 'sect233r1', 'sect239k1', 'sect283k1', 'sect283r1', 'sect409k1', 'sect409r1', 'sect571k1', 'sect571r1', 'wap-wsg-idm-ecid-wtls1', 'wap-wsg-idm-ecid-wtls10', 'wap-wsg-idm-ecid-wtls11', 'wap-wsg-idm-ecid-wtls12', 'wap-wsg-idm-ecid-wtls3', 'wap-wsg-idm-ecid-wtls4', 'wap-wsg-idm-ecid-wtls5', 'wap-wsg-idm-ecid-wtls6', 'wap-wsg-idm-ecid-wtls7', 'wap-wsg-idm-ecid-wtls8', 'wap-wsg-idm-ecid-wtls9' ]
crypto的MD5加密MD5是一种常用的哈希算法，用于给任意数据一个“签名”。这个签名通常用一个十六进制的字符串表示：
crypto.createHash(algorithm)创建并返回一个哈希对象，使用指定的算法来生成哈希摘要。
参数 algorithm 取决于平台上 OpenSSL 版本所支持的算法。例如，'sha1', 'md5', 'sha256', 'sha512' 等等
hash.update(data[, input_encoding])