我找不到任何对我有帮助的东西。我在保留 smime 电子邮件的签名时遇到问题。 我正在尝试获取加密的 smime 消息，解密它，然后将其保存到数据库(用于工作)。由于消息首先被签名然后被加密，所以我认为在解密后保留签名没有问题。我可以成功解密消息。当我尝试获取经过签名和加密的邮件时，它不起作用。 我正在使用 Java (1.8) 和 bouncycaSTLe (jdk15on_154)。这一切都发生在一个具有静态方法的类中(因为我实际上是从 delphi 程序中调用解密)。
这是类(class):
public static void startSMimeDecryption (final String encryptedPath, String decryptedPath) {
logger.info("*** Start of sMIME decryption ***"); //$NON-NLS-1$
Properties props = System.getProperties();
Session session = Session.getDefaultInstance(props, null);
try {
logger.info("Encrypted message: [" + encryptedPath + "]"); //$NON-NLS-1$ //$NON-NLS-2$
File messageFile = new File(encryptedPath);
String fileExtension = getFileExtension(messageFile);
if (fileExtension != null) {
MimeMessage m = null;
if (fileExtension.toUpperCase().equals("EML")) { //$NON-NLS-1$
try (FileInputStream streamIn = new FileInputStream(encryptedPath);) {
logger.info("Created FileInputStream."); //$NON-NLS-1$
m = new MimeMessage(session, streamIn);
logger.info("Created MimeMessage."); //$NON-NLS-1$
} catch (IOException e) {
logger.error("Error while trying to read in message via stream. " + e.getMessage());
return;
}
} else if (fileExtension.toUpperCase().equals("MSG")) { //$NON-NLS-1$
m = createMimeMessageFromMsg(session, messageFile);
logger.info("Created MimeMessage."); //$NON-NLS-1$
} else {
throw new InvalidFileException("Not a supported file type (extension). Only '*.eml' and '*.msg' are accepted."); //$NON-NLS-1$
}
if ((m.getFileName() != null) && (m.getFileName().toUpperCase().equals("SMIME.P7M") || Pattern.compile("^\\s*application\\/(x-)?pkcs7-mime.*$", Pattern.DOTALL).matcher(m.getContentType()).matches())) { //$NON-NLS-1$ //$NON-NLS-2$
m = decryptMessage(m);
logger.info("Saving decrypted message to file..."); //$NON-NLS-1$
if (decryptedPath == null) {
String tempPath = messageFile.getAbsolutePath().substring(0, messageFile.getAbsolutePath().lastIndexOf(File.separator));
decryptedPath = tempPath + File.separator + FilenameUtils.removeExtension(messageFile.getName()) + "_decrypted.eml"; //$NON-NLS-1$
}
try (OutputStream str = Files.newOutputStream(Paths.get(decryptedPath))) {
m.writeTo(str);
} catch (IOException e) {
logger.error("Failed to write to output stream. " + e.getMessage()); //$NON-NLS-1$
return;
}
logger.info("Decrypted message: [" + decryptedPath + "]"); //$NON-NLS-1$ //$NON-NLS-2$
} else {
throw new NotEncryptedMessageException("Not an encrypted message. Breaking up decryption."); //$NON-NLS-1$
}
} else {
throw new InvalidFileException("No file extension found."); //$NON-NLS-1$
}
} catch (MessagingException | UnrecoverableKeyException | KeyStoreException | NoSuchAlgorithmException
| CMSException | InvalidFileException | InvalidMessageException e) {
logger.error("Failed to read message. " + e.getMessage()); //$NON-NLS-1$
} catch (NotEncryptedMessageException e) {
logger.error(e.getMessage());
System.exit(RETURNCODE_NODECRYPTION);
}
logger.info("*** End of sMIME decryption ***"); //$NON-NLS-1$
}
private static MimeMessage createMimeMessageFromMsg (final Session session, final File messageFile) {
MimeMessage mimeMsg = null;
if (messageFile != null) {
MAPIMessage mapiMsg = null;
logger.info("Converting .msg to MimeMessage."); //$NON-NLS-1$
try (NPOIFSFileSystem npoi = new NPOIFSFileSystem(messageFile)) {
logger.info("Created NPOIFSFileSystem."); //$NON-NLS-1$
mapiMsg = new MAPIMessage(npoi);
logger.info("Created MAPIMessage."); //$NON-NLS-1$
mimeMsg = new MimeMessage(session);
logger.info("Creating MimeMessage..."); //$NON-NLS-1$
// Header übertragen
try {
for (String current : mapiMsg.getHeaders()) {
try {
mimeMsg.addHeaderLine(current);
} catch (MessagingException e) {
logger.error("Could not add header line to MimeMessage. " + e.getMessage()); //$NON-NLS-1$
}
}
logger.info("Added header to MimeMessage."); //$NON-NLS-1$
} catch (ChunkNotFoundException e) {
logger.error("Could not retrieve header. " + e.getMessage()); //$NON-NLS-1$
}
// "Attachment" übertragen
for (AttachmentChunks current : mapiMsg.getAttachmentFiles()) {
try {
ByteArrayDataSource ds = new ByteArrayDataSource(current.getEmbeddedAttachmentObject(), "application/pkcs7-mime"); //$NON-NLS-1$
DataHandler dh = new DataHandler(ds);
mimeMsg.setDataHandler(dh);
logger.info("Added attachment to MimeMessage."); //$NON-NLS-1$
} catch (MessagingException e) {
logger.error("Could not transfer attachment into MimeMessage. " + e.getMessage()); //$NON-NLS-1$
}
}
} catch (IOException e) {
logger.error("Error while trying to build MimeMessage. " + e.getMessage()); //$NON-NLS-1$
mimeMsg = null;
}
}
return mimeMsg;
}
private static MimeMessage decryptMessage(final MimeMessage encrypted) throws MessagingException, CMSException,
KeyStoreException, UnrecoverableKeyException,
NoSuchAlgorithmException, InvalidMessageException {
if (encrypted != null) {
logger.info("Starting decrypting message..."); //$NON-NLS-1$
KeyStore keystore = getKeyStore();
SMIMEEnveloped message = new SMIMEEnveloped(encrypted);
RecipientInformationStore recinfos = message.getRecipientInfos();
Enumeration<String> aliases = keystore.aliases();
RecipientInformation recid = null;
String alias = null;
logger.info("Decrypting message..."); //$NON-NLS-1$
while ((recid == null) && aliases.hasMoreElements()) {
alias = aliases.nextElement();
if (keystore.isKeyEntry(alias)) {
Certificate cert = keystore.getCertificate(alias);
recid = recinfos.get(new JceKeyTransRecipientId((X509Certificate) cert));
}
}
if (recid == null) {
throw new RuntimeException("No decryption key found"); //$NON-NLS-1$
}
JceKeyTransEnvelopedRecipient recipient = new JceKeyTransEnvelopedRecipient((PrivateKey) keystore.getKey(alias, "changeit".toCharArray())); //$NON-NLS-1$
byte[] content = recid.getContent(recipient);
logger.info("Setting MimeMessage properties."); //$NON-NLS-1$
MimeMessage decrypted = new MimeMessage(Session.getDefaultInstance(System.getProperties()), new ByteArrayInputStream(content));
Enumeration<Header> headers = encrypted.getAllHeaders();
while (headers.hasMoreElements()) {
Header h = headers.nextElement();
if (decrypted.getHeader(h.getName()) == null) {
decrypted.addHeader(h.getName(), h.getValue());
}
}
decrypted.saveChanges();
logger.info("Decrypted message."); //$NON-NLS-1$
return decrypted;
} else {
throw new InvalidMessageException("Encrypted MimeMessage is null."); //$NON-NLS-1$
}
}
任何人都可以帮助我或解释为什么加密的消息工作得很好，签名和加密根本不起作用(我得到了一个毫无意义的损坏文件)。 如果我没有正确发布此内容，我很抱歉(这是我的第一篇文章)。 谢谢您的回复。
编辑:当我使用加密和签名的电子邮件运行上述代码时，我收到一条如下所示的 mime 消息:
Content-Type: application/x-pkcs7-mime; name=smime.p7m; smime-
type=signed-data
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7m
MIME-Version: 1.0
Message-ID: <29771042.0.1481123386349.JavaMail.NAME@COMPUTER_NAME>
MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwGggCSABIIP
0ENvbnRlbnQtVHlwZTogbXVsdGlwYXJ0L2FsdGVybmF0aXZlOw0KCWJvdW5kYXJ5PSItLS0tPV9O [...]
最佳答案
您的程序失败，因为“签名并加密”的 S/MIME 消息不是 SMIMEEnveloped。数据格式错误。
签名
如果您只是签署一条消息，您会得到类似的结构
- header 将其标识为签名消息
- 已签名的数据(“消息”)
- 签名信息(“签名”)
加密(封装)
如果您只是加密消息，您会得到类似的结构
- header 将其标识为封装消息
- 对于每个收件人
- 如何知道您是该特定加密 key 的接收者
- 为此收件人加密的消息加密 key
- 加密消息
“签名并加密”
应用这个概念时并没有独特的结构。相反，它只使用前面的两个结构:
- header 将其标识为签名消息
- 封装/加密的消息(封装的消息是签名的内容)
- 签名信息
所以发送时的操作是
- 加密消息
- 对消息进行签名以证明加密未被篡改
作为收件人，您需要按照其他顺序执行操作:
- 验证签名
- 解密
后果
因此，对于签名和加密，您需要首先将其作为签名消息读取，然后提取签名内容并将其作为信封消息读取。
这真正的意思是你不能只保留签名和解密的内容，因为签名覆盖了加密的内容。您需要完整保存整个原始签名消息，以便稍后能够验证签名。
关于java - 保留 SMIME 解密邮件的签名，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41020812/