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Validate IpSecAlgorithm Length

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Improve the Validation of IpSecAlgorithm by
explicitly checking the length in addition to
the truncation length (previously an oversight).
In addition, we now check the lengths during
un-parceling, which will catch someone maliciously
manually building a parcel and passing it, bypassing
the checks in the constructor.

Bug: 68780091
Test: runtest -x IpSecAlgorithmTest.java
Change-Id: I8172762617264d34f47d5144336464510f07a701
This commit is contained in:
Nathan Harold
2017-11-09 16:49:33 -08:00
parent 2725a233c9
commit eb1d489332
1 changed files with 50 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

72
core/java/android/net/IpSecAlgorithm.java
View File

@@ -21,6 +21,7 @@ import android.os.Build;
import android.os.Parcel;
import android.os.Parcelable;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.util.HexDump;
import java.lang.annotation.Retention;
@@ -34,6 +35,8 @@ import java.util.Arrays;
* Internet Protocol</a>
*/
public final class IpSecAlgorithm implements Parcelable {
private static final String TAG = "IpSecAlgorithm";
/**
* AES-CBC Encryption/Ciphering Algorithm.
*
@@ -45,6 +48,7 @@ public final class IpSecAlgorithm implements Parcelable {
* MD5 HMAC Authentication/Integrity Algorithm. <b>This algorithm is not recommended for use in
* new applications and is provided for legacy compatibility with 3gpp infrastructure.</b>
*
* <p>Keys for this algorithm must be 128 bits in length.
* <p>Valid truncation lengths are multiples of 8 bits from 96 to (default) 128.
*/
public static final String AUTH_HMAC_MD5 = "hmac(md5)";
@@ -53,6 +57,7 @@ public final class IpSecAlgorithm implements Parcelable {
* SHA1 HMAC Authentication/Integrity Algorithm. <b>This algorithm is not recommended for use in
* new applications and is provided for legacy compatibility with 3gpp infrastructure.</b>
*
* <p>Keys for this algorithm must be 160 bits in length.
* <p>Valid truncation lengths are multiples of 8 bits from 96 to (default) 160.
*/
public static final String AUTH_HMAC_SHA1 = "hmac(sha1)";
@@ -60,6 +65,7 @@ public final class IpSecAlgorithm implements Parcelable {
/**
* SHA256 HMAC Authentication/Integrity Algorithm.
*
* <p>Keys for this algorithm must be 256 bits in length.
* <p>Valid truncation lengths are multiples of 8 bits from 96 to (default) 256.
*/
public static final String AUTH_HMAC_SHA256 = "hmac(sha256)";
@@ -67,6 +73,7 @@ public final class IpSecAlgorithm implements Parcelable {
/**
* SHA384 HMAC Authentication/Integrity Algorithm.
*
* <p>Keys for this algorithm must be 384 bits in length.
* <p>Valid truncation lengths are multiples of 8 bits from 192 to (default) 384.
*/
public static final String AUTH_HMAC_SHA384 = "hmac(sha384)";
@@ -74,6 +81,7 @@ public final class IpSecAlgorithm implements Parcelable {
/**
* SHA512 HMAC Authentication/Integrity Algorithm.
*
* <p>Keys for this algorithm must be 512 bits in length.
* <p>Valid truncation lengths are multiples of 8 bits from 256 to (default) 512.
*/
public static final String AUTH_HMAC_SHA512 = "hmac(sha512)";
@@ -130,12 +138,10 @@ public final class IpSecAlgorithm implements Parcelable {
* @param truncLenBits number of bits of output hash to use.
*/
public IpSecAlgorithm(@AlgorithmName String algorithm, @NonNull byte[] key, int truncLenBits) {
if (!isTruncationLengthValid(algorithm, truncLenBits)) {
throw new IllegalArgumentException("Unknown algorithm or invalid length");
}
mName = algorithm;
mKey = key.clone();
mTruncLenBits = Math.min(truncLenBits, key.length * 8);
mTruncLenBits = truncLenBits;
checkValidOrThrow(mName, mKey.length * 8, mTruncLenBits);
}
/** Get the algorithm name */
@@ -169,7 +175,11 @@ public final class IpSecAlgorithm implements Parcelable {
public static final Parcelable.Creator<IpSecAlgorithm> CREATOR =
new Parcelable.Creator<IpSecAlgorithm>() {
public IpSecAlgorithm createFromParcel(Parcel in) {
return new IpSecAlgorithm(in);
final String name = in.readString();
final byte[] key = in.createByteArray();
final int truncLenBits = in.readInt();
return new IpSecAlgorithm(name, key, truncLenBits);
}
public IpSecAlgorithm[] newArray(int size) {
@@ -177,30 +187,47 @@ public final class IpSecAlgorithm implements Parcelable {
}
};
private IpSecAlgorithm(Parcel in) {
mName = in.readString();
mKey = in.createByteArray();
mTruncLenBits = in.readInt();
}
private static void checkValidOrThrow(String name, int keyLen, int truncLen) {
boolean isValidLen = true;
boolean isValidTruncLen = true;
private static boolean isTruncationLengthValid(String algo, int truncLenBits) {
switch (algo) {
switch(name) {
case CRYPT_AES_CBC:
return (truncLenBits == 128 || truncLenBits == 192 || truncLenBits == 256);
isValidLen = keyLen == 128 || keyLen == 192 || keyLen == 256;
break;
case AUTH_HMAC_MD5:
return (truncLenBits >= 96 && truncLenBits <= 128);
isValidLen = keyLen == 128;
isValidTruncLen = truncLen >= 96 && truncLen <= 128;
break;
case AUTH_HMAC_SHA1:
return (truncLenBits >= 96 && truncLenBits <= 160);
isValidLen = keyLen == 160;
isValidTruncLen = truncLen >= 96 && truncLen <= 160;
break;
case AUTH_HMAC_SHA256:
return (truncLenBits >= 96 && truncLenBits <= 256);
isValidLen = keyLen == 256;
isValidTruncLen = truncLen >= 96 && truncLen <= 256;
break;
case AUTH_HMAC_SHA384:
return (truncLenBits >= 192 && truncLenBits <= 384);
isValidLen = keyLen == 384;
isValidTruncLen = truncLen >= 192 && truncLen <= 384;
break;
case AUTH_HMAC_SHA512:
return (truncLenBits >= 256 && truncLenBits <= 512);
isValidLen = keyLen == 512;
isValidTruncLen = truncLen >= 256 && truncLen <= 512;
break;
case AUTH_CRYPT_AES_GCM:
return (truncLenBits == 64 || truncLenBits == 96 || truncLenBits == 128);
// The keying material for GCM is a key plus a 32-bit salt
isValidLen = keyLen == 128 + 32 || keyLen == 192 + 32 || keyLen == 256 + 32;
break;
default:
return false;
throw new IllegalArgumentException("Couldn't find an algorithm: " + name);
}
if (!isValidLen) {
throw new IllegalArgumentException("Invalid key material keyLength: " + keyLen);
}
if (!isValidTruncLen) {
throw new IllegalArgumentException("Invalid truncation keyLength: " + truncLen);
}
}
@@ -217,8 +244,9 @@ public final class IpSecAlgorithm implements Parcelable {
.toString();
}
/** package */
static boolean equals(IpSecAlgorithm lhs, IpSecAlgorithm rhs) {
/** @hide */
@VisibleForTesting
public static boolean equals(IpSecAlgorithm lhs, IpSecAlgorithm rhs) {
if (lhs == null || rhs == null) return (lhs == rhs);
return (lhs.mName.equals(rhs.mName)
&& Arrays.equals(lhs.mKey, rhs.mKey)