1 files changed, 79 insertions, 0 deletions
diff --git a/bundles/org.eclipse.equinox.p2.repository/src/org/eclipse/equinox/internal/p2/repository/helpers/ChecksumHelper.java b/bundles/org.eclipse.equinox.p2.repository/src/org/eclipse/equinox/internal/p2/repository/helpers/ChecksumHelper.java
new file mode 100644
index 000000000..f87747535
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.repository/src/org/eclipse/equinox/internal/p2/repository/helpers/ChecksumHelper.java
@@ -0,0 +1,79 @@
+/*******************************************************************************
+ *  Copyright (c) 2015, 2018 Mykola Nikishov
+ *  All rights reserved. This program and the accompanying materials
+ *  are made available under the terms of the Eclipse Public License v1.0
+ *  which accompanies this distribution, and is available at
+ *  http://www.eclipse.org/legal/epl-v10.html
+ *
+ *  Contributors:
+ *     Mykola Nikishov - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.equinox.internal.p2.repository.helpers;
+
+import java.util.*;
+import java.util.Map.Entry;
+import org.eclipse.equinox.p2.repository.artifact.IArtifactDescriptor;
+
+public class ChecksumHelper {
+
+	private static final String MD5 = "md5"; //$NON-NLS-1$
+
+	/**
+	 * @param property either {@link IArtifactDescriptor#ARTIFACT_CHECKSUM} or {@link IArtifactDescriptor#DOWNLOAD_CHECKSUM}
+	 * @return (mutable) map of <algorithm,checksum>
+	 * @throws IllegalArgumentException if checksum property neither {@link IArtifactDescriptor#ARTIFACT_CHECKSUM} nor {@link IArtifactDescriptor#DOWNLOAD_CHECKSUM}
+	 */
+	static public Map<String, String> getChecksums(IArtifactDescriptor descriptor, String property) throws IllegalArgumentException {
+		if (!IArtifactDescriptor.ARTIFACT_CHECKSUM.equals(property) && !IArtifactDescriptor.DOWNLOAD_CHECKSUM.equals(property))
+			// TODO provide more details
+			throw new IllegalArgumentException();
+
+		Map<String, String> checksumsByAlgo = new HashMap<>();
+
+		String md5Checksum = getLegacyMd5Checksum(descriptor, property);
+		if (md5Checksum != null) {
+			checksumsByAlgo.put(MD5, md5Checksum);
+		}
+
+		// get checksum properties
+		for (Entry<String, String> p : descriptor.getProperties().entrySet()) {
+			String key = p.getKey();
+			if (key.startsWith(property)) {
+				String checksumAlgorithmId = key // "artifact.checksum.sha3"
+						.substring(property.length()) // ".sha3"
+						.substring(1); // "sha3"
+				String checksumValue = Objects.requireNonNull(p.getValue());
+				String duplicatedChecksum = checksumsByAlgo.put(checksumAlgorithmId, checksumValue);
+				if (duplicatedChecksum != null)
+					// should never happen - duplicated checksum
+					;
+			}
+		}
+
+		return checksumsByAlgo;
+	}
+
+	/**
+	 * @return MD5 checksum from legacy property, either {@link IArtifactDescriptor#DOWNLOAD_MD5} or {@link IArtifactDescriptor#ARTIFACT_MD5}
+	 */
+	private static String getLegacyMd5Checksum(IArtifactDescriptor descriptor, String property) {
+		switch (property) {
+			case IArtifactDescriptor.ARTIFACT_CHECKSUM :
+				return descriptor.getProperty(IArtifactDescriptor.ARTIFACT_MD5);
+			case IArtifactDescriptor.DOWNLOAD_CHECKSUM :
+				return descriptor.getProperty(IArtifactDescriptor.DOWNLOAD_MD5);
+			default :
+				return null;
+		}
+	}
+
+	public static String toHexString(byte[] digest) {
+		StringBuilder buf = new StringBuilder();
+		for (byte element : digest) {
+			if ((element & 0xFF) < 0x10)
+				buf.append('0');
+			buf.append(Integer.toHexString(element & 0xFF));
+		}
+		return buf.toString();
+	}
+}