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-rw-r--r--src/com/isode/stroke/tls/java/JavaCertificate.java365
1 files changed, 284 insertions, 81 deletions
diff --git a/src/com/isode/stroke/tls/java/JavaCertificate.java b/src/com/isode/stroke/tls/java/JavaCertificate.java
index 5b326b9..ccfc568 100644
--- a/src/com/isode/stroke/tls/java/JavaCertificate.java
+++ b/src/com/isode/stroke/tls/java/JavaCertificate.java
@@ -1,11 +1,5 @@
/* Copyright (c) 2012, Isode Limited, London, England.
* All rights reserved.
- *
- * Acquisition and use of this software and related materials for any
- * purpose requires a written licence agreement from Isode Limited,
- * or a written licence from an organisation licensed by Isode Limited Limited
- * to grant such a licence.
- *
*/
package com.isode.stroke.tls.java;
@@ -22,6 +16,7 @@ import java.util.Map;
import javax.security.auth.x500.X500Principal;
import com.isode.stroke.base.ByteArray;
+import com.isode.stroke.base.NotNull;
import com.isode.stroke.tls.Certificate;
/**
@@ -31,20 +26,6 @@ import com.isode.stroke.tls.Certificate;
public class JavaCertificate extends Certificate {
private X509Certificate x509Certificate;
- // There's no ASN.1 help for this in standard Java SDK so for the
- // moment we'll hard-code in the values
- /**
- * ASN.1 encoded representation of OID "1.3.6.1.5.5.7.8.5"
- */
- protected static final byte[] ENCODED_ID_ON_XMPPADD_OID =
- new byte[] { 0x06, 0x08, 0x21, 0x06, 0x01, 0x05, 0x05, 0x07, 0x08, 0x05 };
-
- /**
- * ASN.1 encoded representation of OID "1.3.6.1.5.5.7.8.7"
- */
- protected static final byte[] ENCODED_ID_ON_DNSSRV_OID =
- new byte[] { 0x06, 0x08, 0x21, 0x06, 0x01, 0x05, 0x05, 0x07, 0x08, 0x07 };
-
private static enum GeneralNameType {
OTHERNAME(0),
@@ -71,29 +52,207 @@ public class JavaCertificate extends Certificate {
}
}
+ /**
+ * Returns the computed value of a "length" field for a data structure, i.e.
+ * the size of the data itself, not including its enclosing tag/length.
+ *
+ * @param byteStream an array of bytes containing ASN.1 encoded data
+ *
+ * @param startPos the offset where the "tag" field is to be found
+ *
+ * @return length value
+ *
+ * @throws ArrayIndexOutOfBoundsException if <em>byteStream</em> is
+ * exhausted (most likely it's not valid ASN.1)
+ */
+ private static int getLengthField(byte[] byteStream, int startPos)
+ throws ArrayIndexOutOfBoundsException
+ {
+ int offset = startPos + 1; // skip over "tag"
+
+ /* Since Java treats "byte" values as signed, we use this variable as
+ * a temporary in which a signed value of a given byte may be stored
+ */
+ int unsignedByte;
+
+ /* Extract the "length" byte */
+ unsignedByte = (byteStream[offset] & 0xff);
+
+ /* If it's a "short" length, it will be less than 0x80, and the "length" of
+ * this field can be computed using the value of the length byte
+ */
+ if (unsignedByte < 0x80) {
+ return (unsignedByte);
+ }
+
+ /* Otherwise, the first byte contains information about how the count
+ * of octets that contain length information
+ */
+ int result = 0;
+ offset++; /* advance past the "length-count" byte */
+
+ /* Work out how many octets of length information there are */
+ int numLengthOctets = unsignedByte - 0x80;
+
+ /* Now work out actual "length" */
+ for (int i=0; i<numLengthOctets; i++) {
+ unsignedByte = (byteStream[(i+offset)] & 0xff);
+ result = (result << 8) + unsignedByte;
+ }
+
+ return result;
+
+ }
+ /**
+ * Computes the offset to the "value" in a TLV sequence.
+ *
+ * @param byteStream an array of octets containing BER encoded data.
+ *
+ * @param tagOffset the offset to the "tag" octet inside byteStream.
+ *
+ * @return the offset to the value for the data structure described
+ * by the tag.
+ *
+ * @throws ArrayIndexOutOfBoundsException if <em>byteStream</em> is
+ * exhausted (most likely it's not valid ASN.1)
+ */
+ private final static int getValueOffset(byte[] byteStream, int tagOffset)
+ throws ArrayIndexOutOfBoundsException
+ {
+ int unsignedByte;
+
+ /* Extract the "length" byte */
+ unsignedByte = (byteStream[(tagOffset+1)] & 0xff);
+
+ /*
+ * If it's a "short" length, it will be less than 0x80, and the
+ * "length" of this field can be computed using the value of the
+ * length byte
+ */
+ if (unsignedByte < 0x80) {
+ return (tagOffset + 2); /* add 1 for tag and 1 for length */
+ }
+
+ /*
+ * The value is greater than 0x80, which means that the number of octets
+ * containing the length field can be found by subtracting 0x80 from the
+ * length byte
+ */
+ int numOctets = unsignedByte - 0x80;
+
+ /* Work out where the data must start */
+ return (tagOffset + numOctets + 2);
+ }
+
+ /**
+ * Look for the encoded OID of a value in stream of bytes, and return the
+ * corresponding String that's attached to it
+ *
+ * @param encodedData data stream that may contain the OID
+ *
+ * @param encodedOID the encoded value of the OID to look for
+ *
+ * @return the decoded String corresponding to the requested OID, or null
+ * if it cannot be found, or if an error occurs when decoding
+ */
+ private static String getStringValueForOID(byte[] encodedData, byte[] encodedOID) {
+ /* The "encodedData" comes from X509Certificate.getSubjectAlternativeNames,
+ * which will return something like this:
+ * LBER_SEQUENCE, length = 31 :
+ * tag : 0x06 (LBER_OID), length = 8
+ * value = 1.3.6.1.5.5.7.8.5 (i.e. ID_ON_XMPPADDR_OID)
+ * bytes = [00]=2B [01]=06 [02]=01 [03]=05 [04]=05 [05]=07 [06]=08 [07]=05
+ *
+ * CONTEXT[0], length = 19 :
+ * CONTEXT[0], length = 17 :
+ * tag : 0x0C (LBER_UTF8STRING), length = 15
+ * value = "funky.isode.net"
+ * bytes = [00]=66 [01]=75 [02]=6E [03]=6B [04]=79 [05]=2E [06]=69 [07]=73
+ * [08]=6F [09]=64 [0A]=65 [0B]=2E [0C]=6E [0D]=65 [0E]=74
+ *
+ * Note that the above isn't what you see inside the certificate;
+ * specifically the "CONTEXT[0], length = 19" wrapper appears to have
+ * been synthesized by the Java method.
+ * So this method will look for an embedded UTF8STRING (XMPP) or
+ * IA5STRING (SRVName) that follows the specified OID, regardless of
+ * how many levels of embedding exist.
+ */
+ try {
+ /* Expect the whole thing is a SEQUENCE */
+ if (encodedData[0] != SEQUENCE_TAG) {
+ return null;
+ }
+ int length = getLengthField(encodedData, 0);
+ int oidOffset = getValueOffset(encodedData, 0);
+
+ /* Now we expect the encoded OID */
+ for (int i=0; i<encodedOID.length; i++) {
+ int j = oidOffset + i;
+ if (j >= length) {
+ /* Gone beyond the end of encoded data */
+ return null;
+ }
+ if (encodedOID[i] != encodedData[j]) {
+ /* Found a mismatch in encoded OID */
+ return null;
+ }
+ }
+
+ /* Got this far, so the OID matches */
+ int valueOffset = oidOffset + encodedOID.length;
+
+ /* Now look for a primitive String tag */
+ int curPos = getValueOffset(encodedData, valueOffset);
+ while (curPos < encodedData.length) {
+ byte tag = encodedData[curPos];
+ int componentPos = getValueOffset(encodedData, curPos);
+ int componentLength = getLengthField(encodedData, curPos);
+ if (tag == UTF8STRING_TAG || tag == IA5STRING_TAG) {
+ /*We found a String */
+ String result = new String(encodedData,componentPos, componentLength);
+ return result;
+ }
+ /* It wasn't a String. Move position to next tag */
+ curPos = componentPos;
+ }
+ /* Got through all encoded data without finding a String */
+ return null;
+ }
+ catch (ArrayIndexOutOfBoundsException e) {
+ /* This probably means the data is not properly encoded
+ * ASN.1, or at any rate not in the structure we expected, and
+ * we've blindly followed "length" fields which aren't
+ * really lengths and fallen off the end of the array.
+ */
+ return null;
+ }
+ }
+
private void processSubjectAlternativeNames() {
Collection<List<?>> sans = null;
try {
- // Process subject alternative names. This returns a sequence
- // of general names
+ /* Process subject alternative names. This returns a sequence
+ * of general names
+ */
sans = x509Certificate.getSubjectAlternativeNames();
}
catch (CertificateParsingException e) {
- // Leave all the subjectAltNames unparsed
+ /* Leave all the subjectAltNames unparsed */
return;
}
if (sans == null) {
- // No subjectAltNames
+ /* No subjectAltNames */
return;
}
for (List<?> san : sans) {
- // Each general name element contains an Integer representing the
- // name type, and either a String or byte array containing the
- // value
+ /* Each general name element contains an Integer representing the
+ * name type, and either a String or byte array containing the
+ * value
+ */
Integer type = (Integer)san.get(0);
GeneralNameType nameType = GeneralNameType.getValue(type.intValue());
switch (nameType) {
@@ -101,40 +260,31 @@ public class JavaCertificate extends Certificate {
dnsNames_.add((String)san.get(1));
break;
case OTHERNAME: // DER
- byte[] encoded = (byte[])san.get(1);
- // TODO: what you get here is something like
- // LBER_SEQUENCE, length = 31 :
- // tag : 0x06 (LBER_OID), length = 8
- // value = 1.3.6.1.5.5.7.8.5 (i.e. ID_ON_XMPPADDR_OID)
- // bytes = [00]=2B [01]=06 [02]=01 [03]=05 [04]=05 [05]=07 [06]=08 [07]=05
- //
- // CONTEXT[0], length = 19 :
- // CONTEXT[0], length = 17 :
- // tag : 0x0C UNIVERSAL[12] primitive, length = 15
- // value = "funky.isode.net"
- // bytes = [00]=66 [01]=75 [02]=6E [03]=6B [04]=79 [05]=2E [06]=69 [07]=73
- // [08]=6F [09]=64 [0A]=65 [0B]=2E [0C]=6E [0D]=65 [0E]=74
- //
- // And a corresponding thing for a DNSSRV SAN.
- // However, there's no general ASN.1 decoder in the standard
- // java library, so we will have to implement our own. For
- // now, we ignore these values.
+ byte[] encoding = (byte[])san.get(1);
+ String xmpp = getStringValueForOID(encoding, ENCODED_ID_ON_XMPPADD_OID);
+ if (xmpp != null) {
+ xmppNames_.add(xmpp);
+ break;
+ }
+ String srv = getStringValueForOID(encoding, ENCODED_ID_ON_DNSSRV_OID);
+ if (srv != null) {
+ srvNames_.add(srv);
+ break;
+ }
break;
- case DIRECTORYNAME: // String
- case IPADDRESS: // String
- case REGISTEREDID: // String representation of an OID
- case RFC822NAME: // String
- case UNIFORMRESOURCEIDENTIFIER: // String
- case EDIPARTYNAME: // DER
- case X400ADDRESS: // DER
+ case DIRECTORYNAME: /* String */
+ case IPADDRESS: /* String */
+ case REGISTEREDID: /* String representation of an OID */
+ case RFC822NAME: /* String */
+ case UNIFORMRESOURCEIDENTIFIER: // String */
+ case EDIPARTYNAME: /* DER */
+ case X400ADDRESS: /* DER */
default:
- // Other types of subjectalt names are ignored
+ /* Other types of subjectalt names are ignored */
break;
}
-
}
-
}
/**
@@ -144,18 +294,15 @@ public class JavaCertificate extends Certificate {
*/
public JavaCertificate(X509Certificate x509Cert)
{
- if (x509Cert == null) {
- throw new NullPointerException("x509Cert must not be null");
- }
+ NotNull.exceptIfNull(x509Cert,"x509Cert");
+
x509Certificate = x509Cert;
dnsNames_ = new ArrayList<String>();
srvNames_ = new ArrayList<String>();
xmppNames_ = new ArrayList<String>();
- processSubjectAlternativeNames();
-
-
+ processSubjectAlternativeNames();
}
/**
@@ -191,18 +338,20 @@ public class JavaCertificate extends Certificate {
public List<String> getCommonNames() {
ArrayList<String> result = new ArrayList<String>();
-
- // There isn't a convenient way to extract commonname values from
- // the certificate's subject DN (short of parsing the encoded value
- // ourselves). So instead, we get a String version, ensuring that
- // any CN values have a prefix we can recognize (we could probably
- // rely on "CN" but this allows us to have a more distinctive value)
-
+ /*
+ * There isn't a convenient way to extract commonname values from
+ * the certificate's subject DN (short of parsing the encoded value
+ * ourselves). So instead, we get a String version, ensuring that
+ * any CN values have a prefix we can recognize (we could probably
+ * rely on "CN" but this allows us to have a more distinctive value)
+ */
X500Principal p = x509Certificate.getSubjectX500Principal();
Map<String, String> cnMap = new HashMap<String, String>();
- // Request that the returned String will use our label for any values
- // with the commonName OID
+ /*
+ * Request that the returned String will use our label for any values
+ * with the commonName OID
+ */
cnMap.put(cnOID, cnLabel);
String s = p.getName("RFC2253",cnMap);
@@ -213,9 +362,11 @@ public class JavaCertificate extends Certificate {
return result; // No CN values to add
}
- // Crude attempt to split, noting that this may result in values
- // that contain an escaped comma being chopped between more than one
- // element, so we need to go through this subsequently and handle that..
+ /*
+ * Crude attempt to split, noting that this may result in values
+ * that contain an escaped comma being chopped between more than one
+ * element, so we need to go through this subsequently and handle that..
+ */
String[] split=s.split(",");
boolean inQuote = false;
@@ -237,7 +388,7 @@ public class JavaCertificate extends Certificate {
inQuote = ((quoteCount % 2) == 1);
if (!inQuote && !escape) {
- // We got to the end of a field
+ /* We got to the end of a field */
field += element;
if (field.startsWith(cnPrefix)) {
result.add(field.substring(cnPrefix.length()));
@@ -245,8 +396,9 @@ public class JavaCertificate extends Certificate {
field = "";
}
else {
- // the split has consumed a comma that was part of a quoted
- // String.
+ /* the split has consumed a comma that was part of a quoted
+ * String.
+ */
field = field + element + ",";
}
e++;
@@ -264,8 +416,6 @@ public class JavaCertificate extends Certificate {
*/
@Override
public List<String> getSRVNames() {
- // TODO: At the moment it will always return
- // an empty list -see processSubjectAlternativeNames()
return srvNames_;
}
@@ -292,8 +442,6 @@ public class JavaCertificate extends Certificate {
*/
@Override
public List<String> getXMPPAddresses() {
- // TODO: At the moment it will always return
- // an empty list -see processSubjectAlternativeNames()
return xmppNames_;
}
@@ -305,7 +453,6 @@ public class JavaCertificate extends Certificate {
*/
@Override
public ByteArray toDER() {
- // TODO Auto-generated method stub
try {
byte[] r = x509Certificate.getEncoded();
return new ByteArray(r);
@@ -315,6 +462,35 @@ public class JavaCertificate extends Certificate {
}
}
+ @Override
+ public String toString() {
+ String res = "Certificate for \"" + getSubjectName() + "\"";
+ if (dnsNames_.size() != 0) {
+ String dns = "; DNS names :";
+ for (String s:dnsNames_) {
+ dns += " " + s;
+ }
+ res += dns;
+ }
+
+ if (srvNames_.size() != 0) {
+ String srv = "; SRV names :";
+ for (String s:srvNames_) {
+ srv += " "+ s;
+ }
+ res += srv;
+ }
+
+ if (xmppNames_.size() != 0) {
+ String xmpp = "; XMPP names :";
+ for (String s:xmppNames_) {
+ xmpp += " " + s;
+ }
+ res += xmpp;
+ }
+ return res;
+ }
+
private List<String> dnsNames_ = null;
private List<String> srvNames_ = null;
private List<String> xmppNames_ = null;
@@ -328,4 +504,31 @@ public class JavaCertificate extends Certificate {
*/
private final static String cnLabel = "COMMONNAME";
+ /* There's no ASN.1 help for this in standard Java SDK so for the
+ * moment we'll hard-code in the values
+ */
+ /**
+ * ASN.1 encoded representation of OID "1.3.6.1.5.5.7.8.5"
+ */
+ protected static final byte[] ENCODED_ID_ON_XMPPADD_OID =
+ new byte[] { 0x06, 0x08, 0x2B, 0x06, 0x01, 0x05, 0x05, 0x07, 0x08, 0x05 };
+
+ /**
+ * ASN.1 encoded representation of OID "1.3.6.1.5.5.7.8.7"
+ */
+ protected static final byte[] ENCODED_ID_ON_DNSSRV_OID =
+ new byte[] { 0x06, 0x08, 0x2B, 0x06, 0x01, 0x05, 0x05, 0x07, 0x08, 0x07 };
+
+ /**
+ * The tag expected for a SEQUENCE
+ */
+ protected static final byte SEQUENCE_TAG = 0x30;
+ /**
+ * The tag expected for a UTF8 String
+ */
+ protected static final byte UTF8STRING_TAG = 0x0c;
+ /**
+ * The tag expected for an IA5String
+ */
+ protected static final byte IA5STRING_TAG = 0x16;
}