NIFI-2852 base64 expression language functions

Signed-off-by: jpercivall <joepercivall@yahoo.com>

nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionLexer.g

@@ -127,6 +127,8 @@ UNESCAPE_XML : 'unescapeXml';
 UNESCAPE_CSV : 'unescapeCsv';
 UNESCAPE_HTML3 : 'unescapeHtml3';
 UNESCAPE_HTML4 : 'unescapeHtml4';
+BASE64_ENCODE : 'base64Encode';
+BASE64_DECODE : 'base64Decode';
 
 // 1 arg functions
 SUBSTRING_AFTER	: 'substringAfter';

nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/AttributeExpressionParser.g

@@ -73,7 +73,7 @@ tokens {
 }
 
 // functions that return Strings
-zeroArgString : (TO_UPPER | TO_LOWER | TRIM | TO_STRING | URL_ENCODE | URL_DECODE | ESCAPE_JSON | ESCAPE_XML | ESCAPE_CSV | ESCAPE_HTML3 | ESCAPE_HTML4 | UNESCAPE_JSON | UNESCAPE_XML | UNESCAPE_CSV | UNESCAPE_HTML3 | UNESCAPE_HTML4 ) LPAREN! RPAREN!;
+zeroArgString : (TO_UPPER | TO_LOWER | TRIM | TO_STRING | URL_ENCODE | URL_DECODE | BASE64_ENCODE | BASE64_DECODE | ESCAPE_JSON | ESCAPE_XML | ESCAPE_CSV | ESCAPE_HTML3 | ESCAPE_HTML4 | UNESCAPE_JSON | UNESCAPE_XML | UNESCAPE_CSV | UNESCAPE_HTML3 | UNESCAPE_HTML4 ) LPAREN! RPAREN!;
 oneArgString : ((SUBSTRING_BEFORE | SUBSTRING_BEFORE_LAST | SUBSTRING_AFTER | SUBSTRING_AFTER_LAST | REPLACE_NULL | REPLACE_EMPTY |
 				PREPEND | APPEND | FORMAT | STARTS_WITH | ENDS_WITH | CONTAINS | JOIN | JSON_PATH) LPAREN! anyArg RPAREN!) |
 			   (TO_RADIX LPAREN! anyArg (COMMA! anyArg)? RPAREN!);

nifi-commons/nifi-expression-language/src/main/antlr3/org/apache/nifi/attribute/expression/language/antlr/output/AttributeExpressionLexer.tokens

@@ -86,3 +86,5 @@ URL_DECODE=72
 URL_ENCODE=73
 UUID=74
 WHITESPACE=75
+BASE64_ENCODE=76
+BASE64_DECODE=77

nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/Query.java

@@ -94,6 +94,8 @@ import org.apache.nifi.attribute.expression.language.evaluation.functions.ToUppe
 import org.apache.nifi.attribute.expression.language.evaluation.functions.TrimEvaluator;
 import org.apache.nifi.attribute.expression.language.evaluation.functions.UrlDecodeEvaluator;
 import org.apache.nifi.attribute.expression.language.evaluation.functions.UrlEncodeEvaluator;
+import org.apache.nifi.attribute.expression.language.evaluation.functions.Base64DecodeEvaluator;
+import org.apache.nifi.attribute.expression.language.evaluation.functions.Base64EncodeEvaluator;
 import org.apache.nifi.attribute.expression.language.evaluation.functions.UuidEvaluator;
 import org.apache.nifi.attribute.expression.language.evaluation.literals.BooleanLiteralEvaluator;
 import org.apache.nifi.attribute.expression.language.evaluation.literals.NumberLiteralEvaluator;
@@ -192,6 +194,8 @@ import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpre
 import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.TRUE;
 import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.URL_DECODE;
 import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.URL_ENCODE;
+import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.BASE64_DECODE;
+import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.BASE64_ENCODE;
 import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.ESCAPE_JSON;
 import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.ESCAPE_CSV;
 import static org.apache.nifi.attribute.expression.language.antlr.AttributeExpressionParser.ESCAPE_HTML3;
@@ -933,6 +937,14 @@ public class Query {
                 verifyArgCount(argEvaluators, 0, "urlDecode");
                 return addToken(new UrlDecodeEvaluator(toStringEvaluator(subjectEvaluator)), "urlDecode");
             }
+            case BASE64_ENCODE: {
+                verifyArgCount(argEvaluators, 0, "base64Encode");
+                return addToken(new Base64EncodeEvaluator(toStringEvaluator(subjectEvaluator)), "base64Encode");
+            }
+            case BASE64_DECODE: {
+                verifyArgCount(argEvaluators, 0, "base64Decode");
+                return addToken(new Base64DecodeEvaluator(toStringEvaluator(subjectEvaluator)), "base64Decode");
+            }
             case ESCAPE_CSV: {
                 verifyArgCount(argEvaluators, 0, "escapeCsv");
                 return addToken(CharSequenceTranslatorEvaluator.csvEscapeEvaluator(toStringEvaluator(subjectEvaluator)), "escapeJson");

nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/functions/Base64DecodeEvaluator.java

@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.attribute.expression.language.evaluation.functions;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Base64;
+import java.util.Map;
+
+import org.apache.nifi.attribute.expression.language.evaluation.Evaluator;
+import org.apache.nifi.attribute.expression.language.evaluation.QueryResult;
+import org.apache.nifi.attribute.expression.language.evaluation.StringEvaluator;
+import org.apache.nifi.attribute.expression.language.evaluation.StringQueryResult;
+
+public class Base64DecodeEvaluator extends StringEvaluator {
+
+    private final Evaluator<String> subject;
+
+    public Base64DecodeEvaluator(final Evaluator<String> subject) {
+        this.subject = subject;
+    }
+
+    @Override
+    public QueryResult<String> evaluate(final Map<String, String> attributes) {
+        final String subjectValue = subject.evaluate(attributes).getValue();
+        if (subjectValue == null) {
+            return new StringQueryResult(null);
+        }
+
+        try {
+            return new StringQueryResult(new String(Base64.getDecoder().decode(subjectValue), "UTF-8"));
+        } catch (final UnsupportedEncodingException e) {
+            return null;    // won't happen. It's UTF-8
+        }
+    }
+
+    @Override
+    public Evaluator<?> getSubjectEvaluator() {
+        return subject;
+    }
+
+}

nifi-commons/nifi-expression-language/src/main/java/org/apache/nifi/attribute/expression/language/evaluation/functions/Base64EncodeEvaluator.java

@@ -0,0 +1,55 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.nifi.attribute.expression.language.evaluation.functions;
+
+import java.io.UnsupportedEncodingException;
+import java.util.Base64;
+import java.util.Map;
+
+import org.apache.nifi.attribute.expression.language.evaluation.Evaluator;
+import org.apache.nifi.attribute.expression.language.evaluation.QueryResult;
+import org.apache.nifi.attribute.expression.language.evaluation.StringEvaluator;
+import org.apache.nifi.attribute.expression.language.evaluation.StringQueryResult;
+
+public class Base64EncodeEvaluator extends StringEvaluator {
+
+    private final Evaluator<String> subject;
+
+    public Base64EncodeEvaluator(final Evaluator<String> subject) {
+        this.subject = subject;
+    }
+
+    @Override
+    public QueryResult<String> evaluate(final Map<String, String> attributes) {
+        final String subjectValue = subject.evaluate(attributes).getValue();
+        if (subjectValue == null) {
+            return new StringQueryResult(null);
+        }
+
+        try {
+            return new StringQueryResult(Base64.getEncoder().encodeToString(subjectValue.getBytes("UTF-8")));
+        } catch (final UnsupportedEncodingException e) {
+            return null;    // won't happen.
+        }
+    }
+
+    @Override
+    public Evaluator<?> getSubjectEvaluator() {
+        return subject;
+    }
+
+}

nifi-commons/nifi-expression-language/src/test/java/org/apache/nifi/attribute/expression/language/TestQuery.java

@@ -1020,6 +1020,22 @@ public class TestQuery {
         verifyEquals("${filename:substringAfter('-'):toNumber():toRadix(36, 3):toUpper()}", attributes, "073");
     }
 
+    @Test
+    public void testBase64Encode(){
+        final Map<String, String> attributes = new HashMap<>();
+        attributes.put("userpass", "admin:admin");
+        verifyEquals("${userpass:base64Encode()}", attributes, "YWRtaW46YWRtaW4=");
+
+    }
+
+    @Test
+    public void testBase64Decode(){
+        final Map<String, String> attributes = new HashMap<>();
+        attributes.put("userpassbase64", "YWRtaW46YWRtaW4=");
+        verifyEquals("${userpassbase64:base64Decode()}", attributes, "admin:admin");
+
+    }
+
     @Test
     public void testDateFormatConversion() {
         final Map<String, String> attributes = new HashMap<>();

nifi-docs/src/main/asciidoc/expression-language-guide.adoc

@@ -1179,6 +1179,42 @@ Each of the following functions will encode a string according the rules of the
 
 
 
+
+[.function]
+=== base64Encode
+
+*Description*: [.description]#Returns a Base64 encoded string. This is useful for being able to transfer binary data as ascii.#
+
+*Subject Type*: [.subject]#String#
+
+*Arguments*: No arguments
+
+*Return Type*: [.returnType]#String#
+
+*Examples*: We can Base64-Encoded an attribute named "payload" by using the Expression 
+	   `${payload:base64Encode()}` If the attribute payload had a value of "admin:admin"
+	    then the Expression  `${payload:base64Encode()}` will return "YWRtaW46YWRtaW4=". 
+
+
+
+
+[.function]
+=== base64Decode
+
+*Description*: [.description]#Reverses the Base64 encoding on given string.#
+
+*Subject Type*: [.subject]#String#
+
+*Arguments*: No arguments
+
+*Return Type*: [.returnType]#String#
+
+*Examples*: If we have a Base64-Encoded attribute named "payload" with the value
+	"YWRtaW46YWRtaW4=", then the Expression
+	`${payload:base64Decode()}` will return "admin:admin".
+
+
+
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