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Automated Test: feature-authz-crypto-implementation #312

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11 changes: 11 additions & 0 deletions authz/client/pom.xml
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,17 @@
<artifactId>jackson-annotations</artifactId>
<scope>provided</scope>
</dependency>

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hamcrest</groupId>
<artifactId>hamcrest</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<build>
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
import org.keycloak.authorization.client.resource.ProtectionResource;
import org.keycloak.authorization.client.util.Http;
import org.keycloak.authorization.client.util.TokenCallable;
import org.keycloak.common.crypto.CryptoIntegration;
import org.keycloak.common.util.KeycloakUriBuilder;
import org.keycloak.representations.AccessTokenResponse;
import org.keycloak.util.SystemPropertiesJsonParserFactory;
Expand Down Expand Up @@ -91,6 +92,7 @@ public static AuthzClient create(InputStream configStream) throws RuntimeExcepti
* @return a new instance
*/
public static AuthzClient create(Configuration configuration) {
CryptoIntegration.init(AuthzClient.class.getClassLoader());
return new AuthzClient(configuration);
}

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Original file line number Diff line number Diff line change
@@ -0,0 +1,203 @@
/*
* Copyright 2024 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/

package org.keycloak.authorization.client.util.crypto;

import java.io.ByteArrayInputStream;
import java.io.EOFException;
import java.io.IOException;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.List;

/**
*
* @author rmartinc
*/
class ASN1Decoder {

private final ByteArrayInputStream is;
private final int limit;
private int count;

ASN1Decoder(byte[] bytes) {
is = new ByteArrayInputStream(bytes);
count = 0;
limit = bytes.length;
}

public static ASN1Decoder create(byte[] bytes) {
return new ASN1Decoder(bytes);
}

public List<byte[]> readSequence() throws IOException {
int tag = readTag();
int tagNo = readTagNumber(tag);
if (tagNo != ASN1Encoder.SEQUENCE) {
throw new IOException("Invalid Sequence tag " + tagNo);
}
int length = readLength();
List<byte[]> result = new ArrayList<>();
while (length > 0) {
byte[] bytes = readNext();
result.add(bytes);
length = length - bytes.length;
}
return result;
}
Comment on lines +49 to +63

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⚠️ Potential issue | 🟠 Major

Potential length mismatch in readSequence() loop.

The length variable holds the content length of the SEQUENCE (excluding tag and length bytes). However, readNext() returns the complete TLV (tag + length + value) bytes. Subtracting bytes.length from length will result in incorrect tracking, potentially causing the loop to terminate early or continue past the sequence boundary.

🐛 Proposed fix

Track the bytes consumed during readNext() separately, or compute only the value portion length:

     public List<byte[]> readSequence() throws IOException {
         int tag = readTag();
         int tagNo = readTagNumber(tag);
         if (tagNo != ASN1Encoder.SEQUENCE) {
             throw new IOException("Invalid Sequence tag " + tagNo);
         }
         int length = readLength();
+        int startCount = count;
         List<byte[]> result = new ArrayList<>();
-        while (length > 0) {
+        while (count - startCount < length) {
             byte[] bytes = readNext();
             result.add(bytes);
-            length = length - bytes.length;
         }
         return result;
     }

Alternatively, track consumed bytes within the loop by noting count before and after readNext().

🤖 Prompt for AI Agents
In
`@authz/client/src/main/java/org/keycloak/authorization/client/util/crypto/ASN1Decoder.java`
around lines 49 - 63, In readSequence(), the loop subtracts the full TLV byte
array returned by readNext() from the SEQUENCE content length, causing a
mismatch; change the loop in ASN1Decoder.readSequence to decrement length by
only the value (V) portion length consumed (not the entire TLV), e.g. obtain the
value length from the TLV metadata or by querying the length parsed by
readNext()/readLength() or by measuring the stream position before/after calling
readNext(), and use that consumed-value-length to update length while retaining
the existing tag check against ASN1Encoder.SEQUENCE.


public BigInteger readInteger() throws IOException {
int tag = readTag();
int tagNo = readTagNumber(tag);
if (tagNo != ASN1Encoder.INTEGER) {
throw new IOException("Invalid Integer tag " + tagNo);
}
int length = readLength();
byte[] bytes = read(length);
return new BigInteger(bytes);
}

byte[] readNext() throws IOException {
mark();
int tag = readTag();
readTagNumber(tag);
int length = readLength();
length += reset();
return read(length);
}

int readTag() throws IOException {
int tag = read();
if (tag < 0) {
throw new EOFException("EOF found inside tag value.");
}
return tag;
}

int readTagNumber(int tag) throws IOException {
int tagNo = tag & 0x1f;

//
// with tagged object tag number is bottom 5 bits, or stored at the start of the content
//
if (tagNo == 0x1f) {
tagNo = 0;

int b = read();

// X.690-0207 8.1.2.4.2
// "c) bits 7 to 1 of the first subsequent octet shall not all be zero."
if ((b & 0x7f) == 0) // Note: -1 will pass
{
throw new IOException("corrupted stream - invalid high tag number found");
}

while ((b >= 0) && ((b & 0x80) != 0)) {
tagNo |= (b & 0x7f);
tagNo <<= 7;
b = read();
}

if (b < 0) {
throw new EOFException("EOF found inside tag value.");
}

tagNo |= (b & 0x7f);
}

return tagNo;
}

int readLength() throws IOException {
int length = read();
if (length < 0) {
throw new EOFException("EOF found when length expected");
}

if (length == 0x80) {
return -1; // indefinite-length encoding
}

if (length > 127) {
int size = length & 0x7f;

// Note: The invalid long form "0xff" (see X.690 8.1.3.5c) will be caught here
if (size > 4) {
throw new IOException("DER length more than 4 bytes: " + size);
}

length = 0;
for (int i = 0; i < size; i++) {
int next = read();

if (next < 0) {
throw new EOFException("EOF found reading length");
}

length = (length << 8) + next;
}

if (length < 0) {
throw new IOException("corrupted stream - negative length found");
}

if (length >= limit) // after all we must have read at least 1 byte
{
throw new IOException("corrupted stream - out of bounds length found");
}
Comment on lines +156 to +163

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⚠️ Potential issue | 🟡 Minor

Bounds check may be incorrect for partially-read streams.

The check length >= limit uses limit (total input size) but doesn't account for bytes already consumed (count). A length value that exceeds remaining bytes should be rejected.

🛡️ Suggested improvement
-            if (length >= limit) // after all we must have read at least 1 byte
+            if (length > limit - count) // check against remaining bytes
             {
                 throw new IOException("corrupted stream - out of bounds length found");
             }
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
if (length < 0) {
throw new IOException("corrupted stream - negative length found");
}
if (length >= limit) // after all we must have read at least 1 byte
{
throw new IOException("corrupted stream - out of bounds length found");
}
if (length < 0) {
throw new IOException("corrupted stream - negative length found");
}
if (length > limit - count) // check against remaining bytes
{
throw new IOException("corrupted stream - out of bounds length found");
}
🤖 Prompt for AI Agents
In
`@authz/client/src/main/java/org/keycloak/authorization/client/util/crypto/ASN1Decoder.java`
around lines 156 - 163, The bounds check in ASN1Decoder that currently uses "if
(length >= limit)" is incorrect for partially-read streams because it ignores
bytes already consumed (count); change it to verify the requested length does
not exceed the remaining bytes by using "if (length > (limit - count))" (or
equivalent) so that length larger than the remaining buffer throws, while valid
lengths that fit the remaining bytes are allowed.

}

return length;
}

byte[] read(int length) throws IOException {
byte[] bytes = new byte[length];
int totalBytesRead = 0;

while (totalBytesRead < length) {
int bytesRead = is.read(bytes, totalBytesRead, length - totalBytesRead);
if (bytesRead == -1) {
throw new IOException(String.format("EOF found reading %d bytes", length));
}
totalBytesRead += bytesRead;
}
count += length;
return bytes;
}

void mark() {
count = 0;
is.mark(is.available());
}

int reset() {
int tmp = count;
is.reset();
return tmp;
}

int read() {
int tmp = is.read();
if (tmp >= 0) {
count++;
}
return tmp;
}
}

Original file line number Diff line number Diff line change
@@ -0,0 +1,101 @@
/*
* Copyright 2024 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/

package org.keycloak.authorization.client.util.crypto;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.math.BigInteger;

/**
*
* @author rmartinc
*/
class ASN1Encoder {

static final int INTEGER = 0x02;
static final int SEQUENCE = 0x10;
static final int CONSTRUCTED = 0x20;

private final ByteArrayOutputStream os;

private ASN1Encoder() {
this.os = new ByteArrayOutputStream();
}

static public ASN1Encoder create() {
return new ASN1Encoder();
}

public ASN1Encoder write(BigInteger value) throws IOException {
writeEncoded(INTEGER, value.toByteArray());
return this;
}

public ASN1Encoder writeDerSeq(ASN1Encoder... objects) throws IOException {
writeEncoded(CONSTRUCTED | SEQUENCE, concatenate(objects));
return this;
}

public byte[] toByteArray() {
return os.toByteArray();
}

void writeEncoded(int tag, byte[] bytes) throws IOException {
write(tag);
writeLength(bytes.length);
write(bytes);
}

void writeLength(int length) throws IOException {
if (length > 127) {
int size = 1;
int val = length;

while ((val >>>= 8) != 0) {
size++;
}

write((byte) (size | 0x80));

for (int i = (size - 1) * 8; i >= 0; i -= 8) {
write((byte) (length >> i));
}
} else {
write((byte) length);
}
}

void write(byte[] bytes) throws IOException {
os.write(bytes);
}

void write(int b) throws IOException {
os.write(b);
}

byte[] concatenate(ASN1Encoder... objects) throws IOException {
ByteArrayOutputStream tmp = new ByteArrayOutputStream();
for (ASN1Encoder object : objects) {
tmp.write(object.toByteArray());
}
return tmp.toByteArray();
}
}

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