// This software code is made available "AS IS" without warranties of any
// kind. You may copy, display, modify and redistribute the software
// code either by itself or as incorporated into your code; provided that
// you do not remove any proprietary notices. Your use of this software
// code is at your own risk and you waive any claim against Amazon
// Digital Services, Inc. or its affiliates with respect to your use of
// this software code. (c) 2006 Amazon Digital Services, Inc. or its
// affiliates.
package com.amazon.s3;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.lang.CharEncoding;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLReaderFactory;
public class Utils {
static final String METADATA_PREFIX = "x-amz-meta-";
static final String AMAZON_HEADER_PREFIX = "x-amz-";
static final String ALTERNATIVE_DATE_HEADER = "x-amz-date";
static final String DEFAULT_HOST = "s3.amazonaws.com";
static final int SECURE_PORT = 443;
static final int INSECURE_PORT = 80;
/**
* HMAC/SHA1 Algorithm per RFC 2104.
*/
private static final String HMAC_SHA1_ALGORITHM = "HmacSHA1";
static String makeCanonicalString(String method, String resource, Map headers) {
return makeCanonicalString(method, resource, headers, null);
}
/**
* Calculate the canonical string. When expires is non-null, it will be
* used instead of the Date header.
* @param method
* @param resource
* @param headers
* @param expires
* @return canoncical string
*/
static String makeCanonicalString(String method, String resource,
Map headers, String expires)
{
StringBuilder buf = new StringBuilder();
buf.append(method + "\n");
// Add all interesting headers to a list, then sort them. "Interesting"
// is defined as Content-MD5, Content-Type, Date, and x-amz-
SortedMap interestingHeaders = new TreeMap();
if (headers != null) {
for (Iterator i = headers.keySet().iterator(); i.hasNext(); ) {
String key = (String)i.next();
if (key == null) continue;
String lk = key.toLowerCase();
// Ignore any headers that are not particularly interesting.
if (lk.equals("content-type") || lk.equals("content-md5") || lk.equals("date") ||
lk.startsWith(AMAZON_HEADER_PREFIX))
{
List s = (List)headers.get(key);
interestingHeaders.put(lk, concatenateList(s));
}
}
}
if (interestingHeaders.containsKey(ALTERNATIVE_DATE_HEADER)) {
interestingHeaders.put("date", "");
}
// if the expires is non-null, use that for the date field. this
// trumps the x-amz-date behavior.
if (expires != null) {
interestingHeaders.put("date", expires);
}
// these headers require that we still put a new line in after them,
// even if they don't exist.
if (! interestingHeaders.containsKey("content-type")) {
interestingHeaders.put("content-type", "");
}
if (! interestingHeaders.containsKey("content-md5")) {
interestingHeaders.put("content-md5", "");
}
// Finally, add all the interesting headers (i.e.: all that startwith x-amz- ;-))
for (Iterator i = interestingHeaders.keySet().iterator(); i.hasNext(); ) {
String key = (String)i.next();
if (key.startsWith(AMAZON_HEADER_PREFIX)) {
buf.append(key).append(':').append(interestingHeaders.get(key));
} else {
buf.append(interestingHeaders.get(key));
}
buf.append('\n');
}
// don't include the query parameters...
int queryIndex = resource.indexOf('?');
if (queryIndex == -1) {
buf.append("/" + resource);
} else {
buf.append("/" + resource.substring(0, queryIndex));
}
// ...unless there is an acl or torrent parameter
if (resource.matches(".*[&?]acl($|=|&).*")) {
buf.append("?acl");
} else if (resource.matches(".*[&?]torrent($|=|&).*")) {
buf.append("?torrent");
}
return buf.toString();
}
/**
* Calculate the HMAC/SHA1 on a string.
* @param awsSecretAccessKey passcode to sign with
* @param canonicalString string to sign
* @param urlencode <code>true</code> to urlencode the result
* @return Signature
*/
static String encode(String awsSecretAccessKey, String canonicalString,
boolean urlencode)
{
// The following HMAC/SHA1 code for the signature is taken from the
// AWS Platform's implementation of RFC2104 (amazon.webservices.common.Signature)
//
// Acquire an HMAC/SHA1 from the raw key bytes.
SecretKeySpec signingKey =
new SecretKeySpec(awsSecretAccessKey.getBytes(), HMAC_SHA1_ALGORITHM);
// Acquire the MAC instance and initialize with the signing key.
Mac mac = null;
try {
mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
} catch (NoSuchAlgorithmException e) {
// should not happen
throw new RuntimeException("Could not find sha1 algorithm", e);
}
try {
mac.init(signingKey);
} catch (InvalidKeyException e) {
// also should not happen
throw new RuntimeException("Could not initialize the MAC algorithm", e);
}
// Compute the HMAC on the digest, and set it.
String b64 = Base64.encodeBase64String(mac.doFinal(canonicalString.getBytes()));
if (urlencode) {
return urlencode(b64);
} else {
return b64;
}
}
static String pathForListOptions(String bucket, String prefix, String marker, Integer maxKeys) {
StringBuilder path = new StringBuilder(bucket);
path.append('?');
// these two params must be url encoded
if (prefix != null) path.append("prefix=" + urlencode(prefix) + "&");
if (marker != null) path.append("marker=" + urlencode(marker) + "&");
if (maxKeys != null) path.append("max-keys=" + maxKeys + "&");
path.deleteCharAt(path.length()-1); // we've always added exactly one too many chars
return path.toString();
}
static String urlencode(String unencoded) {
try {
return URLEncoder.encode(unencoded, CharEncoding.UTF_8);
} catch (UnsupportedEncodingException e) {
// should never happen
throw new RuntimeException("Could not url encode to UTF-8", e);
}
}
static XMLReader createXMLReader() {
try {
return XMLReaderFactory.createXMLReader();
} catch (SAXException e) {
// oops, lets try doing this (needed in 1.4)
System.setProperty("org.xml.sax.driver", "org.apache.crimson.parser.XMLReaderImpl");
}
try {
// try once more
return XMLReaderFactory.createXMLReader();
} catch (SAXException e) {
throw new RuntimeException("Couldn't initialize a sax driver for the XMLReader");
}
}
/**
* Concatenates a bunch of header values, seperating them with a comma.
* @param values List of header values.
* @return String of all headers, with commas.
*/
private static String concatenateList(List values) {
StringBuilder buf = new StringBuilder();
for (int i = 0, size = values.size(); i < size; ++ i) {
buf.append(((String)values.get(i)).replaceAll("\n", "").trim());
if (i != (size - 1)) {
buf.append(',');
}
}
return buf.toString();
}
}