Fix encoding of Microdescriptor's getDigestSha256Base64().

CHANGELOG.md

@@ -5,6 +5,8 @@
      and maps to avoid repeating string literals and to use more speedy
      collection types.
    - Simplify and avoid repetition in parse helper methods.
+   - Fix a bug where Microdescriptor's getDigestSha256Base64() returns
+     a hex string rather than a base64 string.
 
 
 # Changes in version 1.7.0 - 2017-05-17

src/main/java/org/torproject/descriptor/impl/MicrodescriptorImpl.java

@@ -243,9 +243,9 @@ public class MicrodescriptorImpl extends DescriptorImpl
         byte[] forDigest = new byte[end - start];
         System.arraycopy(this.getRawDescriptorBytes(), start,
             forDigest, 0, end - start);
-        this.microdescriptorDigest = DatatypeConverter.printHexBinary(
+        this.microdescriptorDigest = DatatypeConverter.printBase64Binary(
             MessageDigest.getInstance("SHA-256").digest(forDigest))
-            .toLowerCase();
+            .replaceAll("=", "");
       }
     } catch (UnsupportedEncodingException e) {
       /* Handle below. */

src/test/java/org/torproject/descriptor/impl/MicrodescriptorImplTest.java

@@ -3,6 +3,8 @@
 
 package org.torproject.descriptor.impl;
 
+import static org.junit.Assert.assertEquals;
+
 import org.torproject.descriptor.DescriptorParseException;
 import org.torproject.descriptor.Microdescriptor;
 
@@ -57,7 +59,9 @@ public class MicrodescriptorImplTest {
 
   @Test()
   public void testDefaults() throws DescriptorParseException {
-    DescriptorBuilder.createWithDefaultLines();
+    Microdescriptor micro = DescriptorBuilder.createWithDefaultLines();
+    assertEquals("ER1AC4KqT//o3pJDrqlmej5G2qW1EQYEr/IrMQHNc6I",
+        micro.getDigestSha256Base64());
   }
 
   @Test(expected = DescriptorParseException.class)