Tim-Zhang · July 9, 2016 03:14 · Jul 9, 2016
diff --git a/HyperAws4.js b/HyperAws4.js
@@ -0,0 +1,157 @@
+import _            from 'lodash'
+import crypto       from 'crypto'
+import urllib       from 'url'
+import querystring  from 'querystring'
+
+const SignedHeaders     = 'content-type;host;x-hyper-content-sha256;x-hyper-date'
+const HeaderContentHash = 'X-Hyper-Content-Sha256'
+const Algorithm         = 'HYPER-HMAC-SHA256'
+const Region            = 'us-west-1'
+const Service           = 'hyper'
+const KeyPartsRequest   = 'hyper_request'
+const KeyPartsPrefix    = 'HYPER'
+
+class Aws4 {
+  constructor({url, method = 'GET', body = '', credential, date}) {
+    Object.assign(this, {url, body, method: method.toUpperCase(), credential},)
+
+    const urlObj  = urllib.parse(url)
+    this.path     = urlObj.pathname
+    this.host     = urlObj.host
+    this.query    = querystring.parse(urlObj.query) || {}
+
+    this.date = date || this.amzDate()
+  }
+
+  hmac(key, string, encoding) {
+    return crypto.createHmac('sha256', key).update(string, 'utf8').digest(encoding)
+  }
+
+  hash(string, encoding = 'hex') {
+    return crypto.createHash('sha256').update(string, 'utf8').digest(encoding)
+  }
+
+  encodeRfc3986(urlEncodedString) {
+    return urlEncodedString.replace(/[!'()*]/g, function(c) {
+      return '%' + c.charCodeAt(0).toString(16).toUpperCase()
+    })
+  }
+
+  amzDate() {
+    return (new Date()).toISOString().replace(/[:\-]|\.\d{3}/g, '')
+  }
+
+  dateStamp() {
+    return this.date.slice(0, 8)
+  }
+
+  payloadHash() {
+    const body = _.isString(this.body) ? this.body : JSON.stringify(this.body)
+    return this.hash(body)
+  }
+
+  canonicalPath() {
+    let pathStr = this.path
+    if (pathStr === '/') return pathStr
+
+    pathStr = pathStr.replace(/\/{2,}/g, '/')
+    pathStr = pathStr.split('/').reduce((path, piece) => {
+      if (piece === '..') {
+        path.pop()
+      } else {
+        path.push(this.encodeRfc3986(querystring.escape(piece)))
+      }
+      return path
+    }, []).join('/')
+
+    if (pathStr[0] === '/') pathStr = pathStr.slice(1)
+
+    return pathStr
+  }
+
+  canonicalQuery() {
+    const query = this.query
+    if (_.isEmpty(query)) return ''
+
+    return this.encodeRfc3986(querystring.stringify(Object.keys(query).sort().reduce((obj, key) => {
+      if (!key) return obj
+      obj[key] = !Array.isArray(query[key]) ? query[key] : query[key].slice().sort()
+      return obj
+    }, {})))
+  }
+
+  canonicalHeaders() {
+    return 'content-type:application/json'
+      + '\nhost:' + this.host
+      + '\nx-hyper-content-sha256:' +  this.payloadHash()
+      + '\nx-hyper-date:' + this.date + '\n'
+  }
+
+  canonicalRequest() {
+    return [
+      this.method,
+      this.canonicalPath(),
+      this.canonicalQuery(),
+      this.canonicalHeaders(),
+      SignedHeaders,
+      this.payloadHash(),
+    ].join('\n')
+  }
+
+  credentialScope() {
+    return [
+      this.dateStamp(),
+      Region,
+      Service,
+      KeyPartsRequest
+    ].join('/')
+  }
+
+  stringToSign() {
+    return [
+      Algorithm,
+      this.date,
+      this.credentialScope(),
+      this.hash(this.canonicalRequest())
+    ].join('\n')
+  }
+
+  signingKey() {
+    const kDate     = this.hmac(KeyPartsPrefix + this.credential.secretKey, this.dateStamp()),
+          kRegion   = this.hmac(kDate, Region),
+          kService  = this.hmac(kRegion, Service),
+          kSigning  = this.hmac(kService, KeyPartsRequest)
+
+    return kSigning
+  }
+
+  signature() {
+    return this.hmac(this.signingKey(), this.stringToSign(), 'hex')
+  }
+
+  // Export
+  // Return signed headers
+  sign() {
+    const date = this.date
+    const payloadHash = this.payloadHash()
+    const host = this.host
+    const credential = `${this.credential.accessKey}/${this.credentialScope()}`
+    const authorization = `${Algorithm} Credential=${credential}, SignedHeaders=${SignedHeaders}, Signature=${this.signature()}`
+
+    return {
+      'Content-Type'      : 'application/json',
+      'X-Hyper-Date'      : date,
+      [HeaderContentHash] : payloadHash,
+      'Host'              : host,
+      'Authorization'     : authorization,
+    }
+  }
+}
+
+
+export default {
+  sign(options) {
+    return (new Aws4(options)).sign()
+  }
+}
+