示例#1
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  /**
   * Returns an array containing all installed providers that satisfy the specified* selection
   * criteria, or null if no such providers have been installed. The returned providers are ordered
   * according to their <a href= "#insertProviderAt(java.security.Provider, int)">preference
   * order</a>.
   *
   * <p>The selection criteria are represented by a map. Each map entry represents a selection
   * criterion. A provider is selected iff it satisfies all selection criteria. The key for any
   * entry in such a map must be in one of the following two formats:
   *
   * <ul>
   *   <li><i>&lt;crypto_service>.&lt;algorithm_or_type></i>
   *       <p>The cryptographic service name must not contain any dots.
   *       <p>The value associated with the key must be an empty string.
   *       <p>A provider satisfies this selection criterion iff the provider implements the
   *       specified algorithm or type for the specified cryptographic service.
   *   <li><i>&lt;crypto_service>.&lt;algorithm_or_type> &lt;attribute_name></i>
   *       <p>The cryptographic service name must not contain any dots. There must be one or more
   *       space charaters between the <i>&lt;algorithm_or_type></i> and the
   *       <i>&lt;attribute_name></i>.
   *       <p>The value associated with the key must be a non-empty string. A provider satisfies
   *       this selection criterion iff the provider implements the specified algorithm or type for
   *       the specified cryptographic service and its implementation meets the constraint expressed
   *       by the specified attribute name/value pair.
   * </ul>
   *
   * <p>See Appendix A in the <a href= "../../../guide/security/CryptoSpec.html#AppA"> Java
   * Cryptogaphy Architecture API Specification &amp; Reference </a> for information about standard
   * cryptographic service names, standard algorithm names and standard attribute names.
   *
   * @param filter the criteria for selecting providers. The filter is case-insensitive.
   * @return all the installed providers that satisfy the selection criteria, or null if no such
   *     providers have been installed.
   * @throws InvalidParameterException if the filter is not in the required format
   * @throws NullPointerException if filter is null
   * @see #getProviders(java.lang.String)
   */
  public static Provider[] getProviders(Map<String, String> filter) {
    // Get all installed providers first.
    // Then only return those providers who satisfy the selection criteria.
    Provider[] allProviders = Security.getProviders();
    Set keySet = filter.keySet();
    LinkedHashSet candidates = new LinkedHashSet(5);

    // Returns all installed providers
    // if the selection criteria is null.
    if ((keySet == null) || (allProviders == null)) {
      return allProviders;
    }

    boolean firstSearch = true;

    // For each selection criterion, remove providers
    // which don't satisfy the criterion from the candidate set.
    for (Iterator ite = keySet.iterator(); ite.hasNext(); ) {
      String key = (String) ite.next();
      String value = (String) filter.get(key);

      LinkedHashSet newCandidates = getAllQualifyingCandidates(key, value, allProviders);
      if (firstSearch) {
        candidates = newCandidates;
        firstSearch = false;
      }

      if ((newCandidates != null) && !newCandidates.isEmpty()) {
        // For each provider in the candidates set, if it
        // isn't in the newCandidate set, we should remove
        // it from the candidate set.
        for (Iterator cansIte = candidates.iterator(); cansIte.hasNext(); ) {
          Provider prov = (Provider) cansIte.next();
          if (!newCandidates.contains(prov)) {
            cansIte.remove();
          }
        }
      } else {
        candidates = null;
        break;
      }
    }

    if ((candidates == null) || (candidates.isEmpty())) return null;

    Object[] candidatesArray = candidates.toArray();
    Provider[] result = new Provider[candidatesArray.length];

    for (int i = 0; i < result.length; i++) {
      result[i] = (Provider) candidatesArray[i];
    }

    return result;
  }
示例#2
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 /**
  * Return the Class object for the given engine type (e.g. "MessageDigest"). Works for Spis in the
  * java.security package only.
  */
 private static Class getSpiClass(String type) {
   Class clazz = spiMap.get(type);
   if (clazz != null) {
     return clazz;
   }
   try {
     clazz = Class.forName("java.security." + type + "Spi");
     spiMap.put(type, clazz);
     return clazz;
   } catch (ClassNotFoundException e) {
     throw (Error) new AssertionError("Spi class not found").initCause(e);
   }
 }
 /*
  * Verify that the provider JAR files are signed properly, which
  * means the signer's certificate can be traced back to a
  * JCE trusted CA.
  * Return null if ok, failure Exception if verification failed.
  */
 static synchronized Exception getVerificationResult(Provider p) {
   Object o = verificationResults.get(p);
   if (o == PROVIDER_VERIFIED) {
     return null;
   } else if (o != null) {
     return (Exception) o;
   }
   if (verifyingProviders.get(p) != null) {
     // this method is static synchronized, must be recursion
     // return failure now but do not save the result
     return new NoSuchProviderException("Recursion during verification");
   }
   try {
     verifyingProviders.put(p, Boolean.FALSE);
     URL providerURL = getCodeBase(p.getClass());
     verifyProviderJar(providerURL);
     // Verified ok, cache result
     verificationResults.put(p, PROVIDER_VERIFIED);
     return null;
   } catch (Exception e) {
     verificationResults.put(p, e);
     return e;
   } finally {
     verifyingProviders.remove(p);
   }
 }