Merge pull request #738 from seadowg/extract-signed

Add `extract-signed`

build.gradle

@@ -168,6 +168,7 @@ dependencies {
  implementation 'commons-io:commons-io:2.5'
 
  implementation 'org.jetbrains.kotlin:kotlin-stdlib:1.6.10'
+ implementation 'org.bouncycastle:bcprov-jdk18on:1.77'
 
  compileOnly 'net.sf.kxml:kxml2:2.3.0'
 

pom.xml

@@ -81,6 +81,11 @@
  <artifactId>slf4j-api</artifactId>
  <version>1.7.33</version>
  </dependency>
+ <dependency>
+ <groupId>org.bouncycastle</groupId>
+ <artifactId>bcprov-jdk18on</artifactId>
+ <version>1.77</version>
+ </dependency>
  <dependency>
  <groupId>ch.qos.logback</groupId>
  <artifactId>logback-classic</artifactId>

src/main/java/org/javarosa/core/util/Base64.java

@@ -0,0 +1,88 @@
+package org.javarosa.core.util;
+
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+
+// Copied from: https:/brsanthu/migbase64/blob/master/src/main/java/com/migcomponents/migbase64/Base64.java
+// Irrelevant after Java8
+public class Base64 {
+
+ private static final char[] BASE_64_TBL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
+ private static final int[] IA = new int[256];
+ static {
+ Arrays.fill(IA, -1);
+ for (int i = 0, iS = BASE_64_TBL.length; i < iS; i++)
+ IA[BASE_64_TBL[i]] = i;
+ IA['='] = 0;
+ }
+
+ public static String encode(byte[] sArr) {
+ int sLen = sArr.length;
+ int sOff = 0;
+
+ if (sLen == 0)
+ return "";
+
+ int eLen = (sLen / 3) * 3;
+ int dLen = ((sLen - 1) / 3 + 1) << 2;
+ byte[] dArr = new byte[dLen];
+
+ for (int s = sOff, d = 0; s < sOff + eLen; ) {
+ int i = (sArr[s++] & 0xff) << 16 | (sArr[s++] & 0xff) << 8 | (sArr[s++] & 0xff);
+ dArr[d++] = (byte) BASE_64_TBL[(i >>> 18) & 0x3f];
+ dArr[d++] = (byte) BASE_64_TBL[(i >>> 12) & 0x3f];
+ dArr[d++] = (byte) BASE_64_TBL[(i >>> 6) & 0x3f];
+ dArr[d++] = (byte) BASE_64_TBL[i & 0x3f];
+ }
+
+ int left = sLen - eLen;
+ if (left > 0) {
+ int i = ((sArr[sOff + eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sOff + sLen - 1] & 0xff) << 2) : 0);
+ dArr[dLen - 4] = (byte) BASE_64_TBL[i >> 12];
+ dArr[dLen - 3] = (byte) BASE_64_TBL[(i >>> 6) & 0x3f];
+ dArr[dLen - 2] = left == 2 ? (byte) BASE_64_TBL[i & 0x3f] : (byte) '=';
+ dArr[dLen - 1] = '=';
+ }
+
+ return new String(dArr, StandardCharsets.UTF_8);
+ }
+
+ public static byte[] decode(byte[] sArr) {
+ int sepCnt = 0;
+ for (byte b : sArr)
+ if (IA[b & 0xff] < 0)
+ sepCnt++;
+
+ if ((sArr.length - sepCnt) % 4 != 0)
+ return new byte[0];
+
+ int pad = 0;
+ for (int i = sArr.length; i > 1 && IA[sArr[--i] & 0xff] <= 0; )
+ if (sArr[i] == '=')
+ pad++;
+
+ int len = ((sArr.length - sepCnt) * 6 >> 3) - pad;
+
+ byte[] dArr = new byte[len];
+
+ for (int s = 0, d = 0; d < len; ) {
+ int i = 0;
+ for (int j = 0; j < 4; j++) {
+ int c = IA[sArr[s++] & 0xff];
+ if (c >= 0)
+ i |= c << (18 - j * 6);
+ else
+ j--;
+ }
+
+ dArr[d++] = (byte) (i >> 16);
+ if (d < len) {
+ dArr[d++] = (byte) (i >> 8);
+ if (d < len)
+ dArr[d++] = (byte) i;
+ }
+ }
+
+ return dArr;
+ }
+}

src/main/java/org/javarosa/core/util/Ed25519.java

@@ -0,0 +1,50 @@
+package org.javarosa.core.util;
+
+import org.bouncycastle.crypto.Signer;
+import org.bouncycastle.crypto.params.Ed25519PublicKeyParameters;
+import org.bouncycastle.crypto.signers.Ed25519Signer;
+import org.jetbrains.annotations.Nullable;
+
+import java.nio.charset.StandardCharsets;
+
+public class Ed25519 {
+
+ private static final int SIGNATURE_LENGTH = 64;
+
+ @Nullable
+ public static String extractSigned(byte[] contents, byte[] publicKey) {
+ if (contents.length < 64) {
+ return null;
+ }
+
+ byte[] signature = new byte[SIGNATURE_LENGTH];
+ System.arraycopy(contents, 0, signature, 0, SIGNATURE_LENGTH);
+
+ int messageLength = contents.length - SIGNATURE_LENGTH;
+ byte[] message = new byte[messageLength];
+ System.arraycopy(contents, SIGNATURE_LENGTH, message, 0, messageLength);
+
+ if (verify(publicKey, signature, message)) {
+ return new String(message, StandardCharsets.UTF_8);
+ } else {
+ return null;
+ }
+ }
+
+ private static boolean verify(byte[] publicKey, byte[] signature, byte[] message) {
+ try {
+ Ed25519PublicKeyParameters publicKeyParameters = new Ed25519PublicKeyParameters(publicKey, 0);
+ Signer signer = new Ed25519Signer();
+ signer.init(false, publicKeyParameters);
+ signer.update(message, 0, message.length);
+
+ return signer.verifySignature(signature);
+ } catch (ArrayIndexOutOfBoundsException e) {
+ // The key was too small
+ return false;
+ } catch (IllegalArgumentException e) {
+ // The key was invalid
+ return false;
+ }
+ }
+}

src/main/java/org/javarosa/xpath/expr/Encoding.java

@@ -15,8 +15,7 @@
  */
 package org.javarosa.xpath.expr;
 
-import java.nio.charset.StandardCharsets;
-import java.util.Arrays;
+import org.javarosa.core.util.Base64;
 import org.javarosa.xpath.XPathUnsupportedException;
 
 /**
@@ -46,78 +45,14 @@ byte[] decode(byte[] bytes) {
  }
  },
  BASE64("base64") {
- // Copied from: https:/brsanthu/migbase64/blob/master/src/main/java/com/migcomponents/migbase64/Base64.java
- // Irrelevant after Java8
  @Override
  String encode(byte[] sArr) {
- int sLen = sArr.length;
- int sOff = 0;
-
- if (sLen == 0)
- return "";
-
- int eLen = (sLen / 3) * 3;
- int dLen = ((sLen - 1) / 3 + 1) << 2;
- byte[] dArr = new byte[dLen];
-
- for (int s = sOff, d = 0; s < sOff + eLen; ) {
- int i = (sArr[s++] & 0xff) << 16 | (sArr[s++] & 0xff) << 8 | (sArr[s++] & 0xff);
- dArr[d++] = (byte) BASE_64_TBL[(i >>> 18) & 0x3f];
- dArr[d++] = (byte) BASE_64_TBL[(i >>> 12) & 0x3f];
- dArr[d++] = (byte) BASE_64_TBL[(i >>> 6) & 0x3f];
- dArr[d++] = (byte) BASE_64_TBL[i & 0x3f];
- }
-
- int left = sLen - eLen;
- if (left > 0) {
- int i = ((sArr[sOff + eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sOff + sLen - 1] & 0xff) << 2) : 0);
- dArr[dLen - 4] = (byte) BASE_64_TBL[i >> 12];
- dArr[dLen - 3] = (byte) BASE_64_TBL[(i >>> 6) & 0x3f];
- dArr[dLen - 2] = left == 2 ? (byte) BASE_64_TBL[i & 0x3f] : (byte) '=';
- dArr[dLen - 1] = '=';
- }
-
- return new String(dArr, StandardCharsets.UTF_8);
+ return Base64.encode(sArr);
  }
 
  @Override
- public byte[] decode(byte[] sArr) {
- int sepCnt = 0;
- for (byte b : sArr)
- if (IA[b & 0xff] < 0)
- sepCnt++;
-
- if ((sArr.length - sepCnt) % 4 != 0)
- return new byte[0];
-
- int pad = 0;
- for (int i = sArr.length; i > 1 && IA[sArr[--i] & 0xff] <= 0; )
- if (sArr[i] == '=')
- pad++;
-
- int len = ((sArr.length - sepCnt) * 6 >> 3) - pad;
-
- byte[] dArr = new byte[len];
-
- for (int s = 0, d = 0; d < len; ) {
- int i = 0;
- for (int j = 0; j < 4; j++) {
- int c = IA[sArr[s++] & 0xff];
- if (c >= 0)
- i |= c << (18 - j * 6);
- else
- j--;
- }
-
- dArr[d++] = (byte) (i >> 16);
- if (d < len) {
- dArr[d++] = (byte) (i >> 8);
- if (d < len)
- dArr[d++] = (byte) i;
- }
- }
-
- return dArr;
+ byte[] decode(byte[] sArr) {
+ return Base64.decode(sArr);
  }
  };
 
@@ -137,16 +72,6 @@ static Encoding from(String name) {
 
  private static final char[] HEX_TBL = "0123456789abcdef".toCharArray();
 
- private static final char[] BASE_64_TBL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
-
- private static final int[] IA = new int[256];
- static {
- Arrays.fill(IA, -1);
- for (int i = 0, iS = BASE_64_TBL.length; i < iS; i++)
- IA[BASE_64_TBL[i]] = i;
- IA['='] = 0;
- }
-
  abstract String encode(byte[] bytes);
 
  abstract byte[] decode(byte[] bytes);

src/main/java/org/javarosa/xpath/expr/XPathFuncExpr.java

@@ -25,6 +25,8 @@
 import org.javarosa.core.model.instance.TreeReference;
 import org.javarosa.core.model.utils.DateUtils;
 import org.javarosa.core.services.PropertyManager;
+import org.javarosa.core.util.Base64;
+import org.javarosa.core.util.Ed25519;
 import org.javarosa.core.util.GeoUtils;
 import org.javarosa.core.util.MathUtils;
 import org.javarosa.core.util.PropertyUtils;
@@ -496,6 +498,9 @@ public Object eval(DataInstance model, EvaluationContext evalContext) {
  } else if (name.equals("base64-decode")) {
  assertArgsCount(name, args, 1);
  return base64Decode(argVals[0]);
+ } else if (name.equals("extract-signed")) {
+ assertArgsCount(name, args, 2);
+ return extractSigned(argVals[0], argVals[1]);
  } else {
  //check for custom handler
  IFunctionHandler handler = funcHandlers.get(name);
@@ -1264,6 +1269,18 @@ private static String base64Decode(Object o1) {
  return new String(decoded, StandardCharsets.UTF_8);
  }
 
+ private static String extractSigned(Object o1, Object o2) {
+ byte[] decodedContents = Base64.decode(toString(o1).getBytes());
+ byte[] decodedPublicKey = Base64.decode(toString(o2).getBytes());
+
+ String extracted = Ed25519.extractSigned(decodedContents, decodedPublicKey);
+ if (extracted != null) {
+ return extracted;
+ } else {
+ return "";
+ }
+ }
+
  private static Object[] subsetArgList(Object[] args, int start) {
  return subsetArgList(args, start, 1);
  }