Introduced MaskingOutputStream to DRY between Pipeline & freestyle

src/main/java/org/jenkinsci/plugins/credentialsbinding/impl/BindingStep.java

@@ -29,7 +29,6 @@
 import hudson.FilePath;
 import hudson.Launcher;
 import hudson.console.ConsoleLogFilter;
-import hudson.console.LineTransformationOutputStream;
 import hudson.model.AbstractBuild;
 import hudson.model.Run;
 import hudson.model.TaskListener;
@@ -49,7 +48,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
@@ -218,24 +216,8 @@ private Object readResolve() throws ObjectStreamException {
             return this;
         }
 
-        @Override public OutputStream decorateLogger(AbstractBuild _ignore, final OutputStream logger) throws IOException, InterruptedException {
-            final Pattern p = Pattern.compile(pattern.getPlainText());
-            return new LineTransformationOutputStream.Delegating(logger) {
-                @Override protected void eol(byte[] b, int len) throws IOException {
-                    if (!p.toString().isEmpty()) {
-                        Matcher m = p.matcher(new String(b, 0, len, charsetName));
-                        if (m.find()) {
-                            out.write(m.replaceAll("****").getBytes(charsetName));
-                        } else {
-                            // Avoid byte → char → byte conversion unless we are actually doing something.
-                            out.write(b, 0, len);
-                        }
-                    } else {
-                        // Avoid byte → char → byte conversion unless we are actually doing something.
-                        out.write(b, 0, len);
-                    }
-                }
-            };
+        @Override public OutputStream decorateLogger(AbstractBuild _ignore, OutputStream logger) throws IOException, InterruptedException {
+            return new SecretPatterns.MaskingOutputStream(logger, () -> Pattern.compile(pattern.getPlainText()), charsetName);
         }
 
     }

src/main/java/org/jenkinsci/plugins/credentialsbinding/impl/SecretBuildWrapper.java

@@ -27,7 +27,6 @@
 import hudson.Extension;
 import hudson.Launcher;
 import hudson.console.ConsoleLogFilter;
-import hudson.console.LineTransformationOutputStream;
 import hudson.model.AbstractBuild;
 import hudson.model.AbstractProject;
 import hudson.model.BuildListener;
@@ -43,7 +42,6 @@
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.*;
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 @SuppressWarnings({"rawtypes", "unchecked"}) // inherited from BuildWrapper
@@ -141,29 +139,8 @@ private static final class Filter extends ConsoleLogFilter {
             this.charsetName = charsetName;
         }
 
-        @Override public OutputStream decorateLogger(final AbstractBuild build, final OutputStream logger) throws IOException, InterruptedException {
-            return new LineTransformationOutputStream.Delegating(logger) {
-                Pattern p;
-
-                @Override protected void eol(byte[] b, int len) throws IOException {
-                    if (p == null) {
-                        p = getPatternForBuild(build);
-                    }
-
-                    if (p != null && !p.toString().isEmpty()) {
-                        Matcher m = p.matcher(new String(b, 0, len, charsetName));
-                        if (m.find()) {
-                            out.write(m.replaceAll("****").getBytes(charsetName));
-                        } else {
-                            // Avoid byte → char → byte conversion unless we are actually doing something.
-                            out.write(b, 0, len);
-                        }
-                    } else {
-                        // Avoid byte → char → byte conversion unless we are actually doing something.
-                        out.write(b, 0, len);
-                    }
-                }
-
+        @Override public OutputStream decorateLogger(AbstractBuild build, OutputStream logger) throws IOException, InterruptedException {
+            return new SecretPatterns.MaskingOutputStream(logger, () -> getPatternForBuild(build), charsetName) {
                 @Override public void close() throws IOException {
                     super.close();
                     secretsForBuild.remove(build);

src/main/java/org/jenkinsci/plugins/credentialsbinding/masking/SecretPatterns.java

@@ -24,16 +24,18 @@
 
 package org.jenkinsci.plugins.credentialsbinding.masking;
 
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
-
-import javax.annotation.Nonnull;
+import edu.umd.cs.findbugs.annotations.CheckForNull;
+import edu.umd.cs.findbugs.annotations.NonNull;
+import hudson.console.LineTransformationOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
 import java.util.Collection;
 import java.util.Comparator;
+import java.util.function.Supplier;
+import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
-@Restricted(NoExternalUse.class)
 public class SecretPatterns {
 
     private static final Comparator<String> BY_LENGTH_DESCENDING =
@@ -48,7 +50,7 @@ public class SecretPatterns {
      * For example, {@code bash -x} will only quote arguments echoed when necessary. To avoid leaking the presence or
      * absence of quoting, the longer form is masked.
      */
-    public static @Nonnull Pattern getAggregateSecretPattern(@Nonnull Collection<String> inputs) {
+    public static @NonNull Pattern getAggregateSecretPattern(@NonNull Collection<String> inputs) {
         String pattern = inputs.stream()
                 .filter(input -> !input.isEmpty())
                 .flatMap(input ->
@@ -60,4 +62,47 @@ public class SecretPatterns {
                 .collect(Collectors.joining("|"));
         return Pattern.compile(pattern);
     }
+
+    /**
+     * Delegating output stream that masks occurrences of a set of secrets.
+     */
+    public static class MaskingOutputStream extends LineTransformationOutputStream.Delegating {
+
+        private final @NonNull Supplier<Pattern> secretPattern;
+        private final @NonNull String charsetName;
+        private @CheckForNull Pattern p;
+
+        /**
+         * @param out the base output stream which will not be sent secrets
+         * @param secretPattern a lazy computation of either the result of {@link #getAggregateSecretPattern}, or null to just skip masking
+         * @param charsetName the character set to detect strings
+         */
+        public MaskingOutputStream(@NonNull OutputStream out, @NonNull Supplier<Pattern> secretPattern, @NonNull String charsetName) {
+            super(out);
+            this.secretPattern = secretPattern;
+            this.charsetName = charsetName;
+        }
+
+        @Override protected void eol(byte[] b, int len) throws IOException {
+            if (p == null) {
+                p = secretPattern.get();
+            }
+            if (p == null || p.toString().isEmpty()) {
+                // Avoid byte → char → byte conversion unless we are actually doing something.
+                out.write(b, 0, len);
+            } else {
+                Matcher m = p.matcher(new String(b, 0, len, charsetName));
+                if (m.find()) {
+                    out.write(m.replaceAll("****").getBytes(charsetName));
+                } else {
+                    // As above.
+                    out.write(b, 0, len);
+                }
+            }
+        }
+
+    }
+
+    private SecretPatterns() {}
+
 }