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91 package com.lowagie.text.pdf;
92
93 import java.io.ByteArrayInputStream  ;
94 import java.io.ByteArrayOutputStream ;
95 import java.io.IOException ;
96
97 import java.security.AlgorithmParameterGenerator ;
98 import java.security.AlgorithmParameters ;
99 import java.security.GeneralSecurityException ;
100 import java.security.NoSuchAlgorithmException ;
101 import java.security.SecureRandom ;
102 import java.security.cert.Certificate ;
103 import java.security.cert.X509Certificate ;
104
105 import java.util.ArrayList ;
106
107 import javax.crypto.Cipher;
108 import javax.crypto.KeyGenerator;
109 import javax.crypto.SecretKey;
110
111 import org.bouncycastle.asn1.ASN1InputStream;
112 import org.bouncycastle.asn1.DERObject;
113 import org.bouncycastle.asn1.DERObjectIdentifier;
114 import org.bouncycastle.asn1.DEROctetString;
115 import org.bouncycastle.asn1.DEROutputStream;
116 import org.bouncycastle.asn1.DERSet;
117 import org.bouncycastle.asn1.cms.ContentInfo;
118 import org.bouncycastle.asn1.cms.EncryptedContentInfo;
119 import org.bouncycastle.asn1.cms.EnvelopedData;
120 import org.bouncycastle.asn1.cms.IssuerAndSerialNumber;
121 import org.bouncycastle.asn1.cms.KeyTransRecipientInfo;
122 import org.bouncycastle.asn1.cms.RecipientIdentifier;
123 import org.bouncycastle.asn1.cms.RecipientInfo;
124 import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers;
125 import org.bouncycastle.asn1.x509.AlgorithmIdentifier;
126 import org.bouncycastle.asn1.x509.TBSCertificateStructure;
127
128
131 public class PdfPublicKeySecurityHandler {
132
133 static final int SEED_LENGTH = 20;
134
135 private ArrayList recipients = null;
136
137 private byte[] seed = new byte[SEED_LENGTH];
138
139 public PdfPublicKeySecurityHandler() {
140 KeyGenerator key;
141 try {
142 key = KeyGenerator.getInstance("AES");
143 key.init(192, new SecureRandom ());
144 SecretKey sk = key.generateKey();
145 System.arraycopy(sk.getEncoded(), 0, seed, 0, SEED_LENGTH); } catch (NoSuchAlgorithmException e) {
147 seed = SecureRandom.getSeed(SEED_LENGTH);
148 }
149
150 recipients = new ArrayList ();
151 }
152
153
154
158
159 static public byte[] unescapedString(byte[] bytes) throws BadPdfFormatException {
160 ByteArrayOutputStream baos = new ByteArrayOutputStream ();
161
162 int index = 0;
163
164 if (bytes[0] != '(' && bytes[bytes.length-1] != ')') throw new BadPdfFormatException("Expect '(' and ')' at begin and end of the string.");
165
166 while (index < bytes.length) {
167 if (bytes[index] == '\\') {
168 index++;
169 switch (bytes[index]) {
170 case 'b':
171 baos.write('\b');
172 break;
173 case 'f':
174 baos.write('\f');
175 break;
176 case 't':
177 baos.write('\t');
178 break;
179 case 'n':
180 baos.write('\n');
181 break;
182 case 'r':
183 baos.write('\r');
184 break;
185 case '(':
186 baos.write('(');
187 break;
188 case ')':
189 baos.write(')');
190 break;
191 case '\\':
192 baos.write('\\');
193 break;
194 }
195 } else
196 baos.write(bytes[index]);
197 index++;
198 }
199 return baos.toByteArray();
200 }
201
202 public void addRecipient(PdfPublicKeyRecipient recipient) {
203 recipients.add(recipient);
204 }
205
206 protected byte[] getSeed() {
207 return (byte[])seed.clone();
208 }
209
214
215 public int getRecipientsSize() {
216 return recipients.size();
217 }
218
219 public byte[] getEncodedRecipient(int index) throws IOException , GeneralSecurityException {
220 PdfPublicKeyRecipient recipient = (PdfPublicKeyRecipient)recipients.get(index);
222 byte[] cms = recipient.getCms();
223
224 if (cms != null) return cms;
225
226 Certificate certificate = recipient.getCertificate();
227 int permission = recipient.getPermission(); int revision = 3;
229
230 permission |= revision==3 ? 0xfffff0c0 : 0xffffffc0;
231 permission &= 0xfffffffc;
232 permission += 1;
233
234 byte[] pkcs7input = new byte[24];
235
236 byte one = (byte)(permission);
237 byte two = (byte)(permission >> 8);
238 byte three = (byte)(permission >> 16);
239 byte four = (byte)(permission >> 24);
240
241 System.arraycopy(seed, 0, pkcs7input, 0, 20);
243 pkcs7input[20] = four;
244 pkcs7input[21] = three;
245 pkcs7input[22] = two;
246 pkcs7input[23] = one;
247
248 DERObject obj = createDERForRecipient(pkcs7input, (X509Certificate )certificate);
249
250 ByteArrayOutputStream baos = new ByteArrayOutputStream ();
251
252 DEROutputStream k = new DEROutputStream(baos);
253
254 k.writeObject(obj);
255
256 cms = baos.toByteArray();
257
258 recipient.setCms(cms);
259
260 return cms;
261 }
262
263 public PdfArray getEncodedRecipients() throws IOException ,
264 GeneralSecurityException {
265 PdfArray EncodedRecipients = new PdfArray();
266 byte[] cms = null;
267 for (int i=0; i<recipients.size(); i++)
268 try {
269 cms = getEncodedRecipient(i);
270 EncodedRecipients.add(new PdfLiteral(PdfContentByte.escapeString(cms)));
271 } catch (GeneralSecurityException e) {
272 EncodedRecipients = null;
273 } catch (IOException e) {
274 EncodedRecipients = null;
275 }
276
277 return EncodedRecipients;
278 }
279
280 private DERObject createDERForRecipient(byte[] in, X509Certificate cert)
281 throws IOException ,
282 GeneralSecurityException
283 {
284
285 String s = "1.2.840.113549.3.2";
286
287 AlgorithmParameterGenerator algorithmparametergenerator = AlgorithmParameterGenerator.getInstance(s);
288 AlgorithmParameters algorithmparameters = algorithmparametergenerator.generateParameters();
289 ByteArrayInputStream bytearrayinputstream = new ByteArrayInputStream (algorithmparameters.getEncoded("ASN.1"));
290 ASN1InputStream asn1inputstream = new ASN1InputStream(bytearrayinputstream);
291 DERObject derobject = asn1inputstream.readObject();
292 KeyGenerator keygenerator = KeyGenerator.getInstance(s);
293 keygenerator.init(128);
294 SecretKey secretkey = keygenerator.generateKey();
295 Cipher cipher = Cipher.getInstance(s);
296 cipher.init(1, secretkey, algorithmparameters);
297 byte[] abyte1 = cipher.doFinal(in);
298 DEROctetString deroctetstring = new DEROctetString(abyte1);
299 KeyTransRecipientInfo keytransrecipientinfo = computeRecipientInfo(cert, secretkey.getEncoded());
300 DERSet derset = new DERSet(new RecipientInfo(keytransrecipientinfo));
301 AlgorithmIdentifier algorithmidentifier = new AlgorithmIdentifier(new DERObjectIdentifier(s), derobject);
302 EncryptedContentInfo encryptedcontentinfo =
303 new EncryptedContentInfo(PKCSObjectIdentifiers.data, algorithmidentifier, deroctetstring);
304 EnvelopedData env = new EnvelopedData(null, derset, encryptedcontentinfo, null);
305 ContentInfo contentinfo =
306 new ContentInfo(PKCSObjectIdentifiers.envelopedData, env);
307 return contentinfo.getDERObject();
308 }
309
310 private KeyTransRecipientInfo computeRecipientInfo(X509Certificate x509certificate, byte[] abyte0)
311 throws GeneralSecurityException , IOException
312 {
313 ASN1InputStream asn1inputstream =
314 new ASN1InputStream(new ByteArrayInputStream (x509certificate.getTBSCertificate()));
315 TBSCertificateStructure tbscertificatestructure =
316 TBSCertificateStructure.getInstance(asn1inputstream.readObject());
317 AlgorithmIdentifier algorithmidentifier = tbscertificatestructure.getSubjectPublicKeyInfo().getAlgorithmId();
318 IssuerAndSerialNumber issuerandserialnumber =
319 new IssuerAndSerialNumber(
320 tbscertificatestructure.getIssuer(),
321 tbscertificatestructure.getSerialNumber().getValue());
322 Cipher cipher = Cipher.getInstance(algorithmidentifier.getObjectId().getId());
323 cipher.init(1, x509certificate);
324 DEROctetString deroctetstring = new DEROctetString(cipher.doFinal(abyte0));
325 RecipientIdentifier recipId = new RecipientIdentifier(issuerandserialnumber);
326 return new KeyTransRecipientInfo( recipId, algorithmidentifier, deroctetstring);
327 }
328 }
329 |
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