Correct the function signatures so they follow the spec and implementation

See #41

Author: adamretter

src/main/java/org/expath/exist/crypto/digest/HashFunction.java

@@ -58,10 +58,19 @@ public class HashFunction extends BasicFunction {
 			"The cryptographic hashing algorithm.");
 
 	public static final FunctionSignature FS_HASH[] = functionSignatures(FS_HASH_NAME,
-			"resulting hash value, as string.", returnsOptMany(Type.BYTE),
-			arities(arity(FS_HASH_PARAM_DATA, FS_HASH_PARAM_ALGORITHM),
-					arity(FS_HASH_PARAM_DATA, FS_HASH_PARAM_ALGORITHM, param("encoding", Type.STRING,
-							"The encoding of the output. The legal values are \"hex\" and \"base64\". The default value is \"base64\"."))));
+			"resulting hash value, as string.", returnsOpt(Type.STRING),
+			arities(
+				arity(
+					FS_HASH_PARAM_DATA,
+					FS_HASH_PARAM_ALGORITHM
+				),
+				arity(
+					FS_HASH_PARAM_DATA,
+					FS_HASH_PARAM_ALGORITHM,
+					optParam("encoding", Type.STRING, "The encoding of the output. The legal values are \"hex\" and \"base64\". The default value is \"base64\".")
+				)
+			)
+	);
 
 	public HashFunction(final XQueryContext context, final FunctionSignature signature) {
 		super(context, signature);

src/main/java/org/expath/exist/crypto/digest/HmacFunction.java

@@ -19,11 +19,7 @@
  */
 package org.expath.exist.crypto.digest;
 
-import static org.exist.xquery.FunctionDSL.arities;
-import static org.exist.xquery.FunctionDSL.arity;
-import static org.exist.xquery.FunctionDSL.optManyParam;
-import static org.exist.xquery.FunctionDSL.param;
-import static org.exist.xquery.FunctionDSL.returnsOptMany;
+import static org.exist.xquery.FunctionDSL.*;
 import static org.expath.exist.crypto.ExistExpathCryptoModule.functionSignatures;
 
 import java.io.IOException;
@@ -60,10 +56,21 @@ public class HmacFunction extends BasicFunction {
 			"The cryptographic hashing algorithm.");
 
 	public final static FunctionSignature FS_HMAC[] = functionSignatures(FS_HMAC_NAME, "Hashes the input message.",
-			returnsOptMany(Type.BYTE),
-			arities(arity(FS_HMAC_PARAM_DATA, FS_HMAC_PARAM_KEY, FS_HMAC_PARAM_ALGORITHM),
-					arity(FS_HMAC_PARAM_DATA, FS_HMAC_PARAM_KEY, FS_HMAC_PARAM_ALGORITHM, param("encoding", Type.STRING,
-							"The encoding of the output. The legal values are \"hex\" and \"base64\". The result is generated accordingly as xs:base64Binary string or xs:hexBinary string."))));
+			returnsOpt(Type.STRING),
+			arities(
+				arity(
+					FS_HMAC_PARAM_DATA,
+					FS_HMAC_PARAM_KEY,
+					FS_HMAC_PARAM_ALGORITHM
+				),
+				arity(
+					FS_HMAC_PARAM_DATA,
+					FS_HMAC_PARAM_KEY,
+					FS_HMAC_PARAM_ALGORITHM,
+					param("encoding", Type.STRING, "The encoding of the output. The legal values are \"hex\" and \"base64\". The result is generated accordingly as xs:base64Binary string or xs:hexBinary string.")
+				)
+			)
+	);
 
 	public HmacFunction(final XQueryContext context, final FunctionSignature signature) {
 		super(context, signature);
@@ -87,24 +94,25 @@ public Sequence eval(final Sequence[] args, final Sequence contextSequence) thro
 			final String algorithm = args[2].getStringValue();
 			LOG.debug("algorithm = {}", algorithm);
 
+			final String encoding;
+			final String resultString;
 			if (argsLength == 3) {
+				encoding = "base64";
 				final byte[] resultBytes;
 				if (data.isLeft()) {
 					try (final InputStream is = data.left().get()) {
-						resultBytes = Hmac.hmac(is, secretKey, algorithm);
+						resultString = Hmac.hmac(is, secretKey, algorithm, encoding);
 					}
 					dataStreamClosed = true;
 				} else {
-					resultBytes = Hmac.hmac(data.right().get(), secretKey, algorithm);
+					resultString = Hmac.hmac(data.right().get(), secretKey, algorithm, encoding);
 				}
 
-				result = Conversion.byteArrayToIntegerSequence(resultBytes);
+				result = new StringValue(resultString);
 			} else if (argsLength == 4) {
-				final String encoding = args[3].getStringValue().isEmpty() ? "base64" : args[3].getStringValue();
+				encoding = args[3].getStringValue().isEmpty() ? "base64" : args[3].getStringValue();
 				LOG.debug("encoding = {}", encoding);
 
-				final String resultString;
-
 				if (data.isLeft()) {
 					try (final InputStream is = data.left().get()) {
 						resultString = Hmac.hmac(is, secretKey, algorithm, encoding);

src/main/java/org/expath/exist/crypto/digitalSignature/GenerateSignatureFunction.java

@@ -32,6 +32,7 @@
 import java.security.PrivateKey;
 import java.util.Optional;
 
+import javax.annotation.Nullable;
 import javax.xml.crypto.dsig.XMLSignatureException;
 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
@@ -211,7 +212,7 @@ public Sequence eval(final Sequence[] args, final Sequence contextSequence) thro
 			Document signatureDocument = null;
 
 			// get the XPath expression and/or the certificate's details
-			String xpathExprString = null;
+			@Nullable String xpathExprString = null;
 			String[] certificateDetails = new String[5];
 			certificateDetails[0] = "";
 			InputStream keyStoreInputStream = null;
@@ -220,7 +221,7 @@ public Sequence eval(final Sequence[] args, final Sequence contextSequence) thro
 
 				// signature with 7 arguments
 				if (args.length == 7) {
-					if (args[6].itemAt(0).getType() == 22) {
+					if (args[6].getItemCount() > 0 && args[6].itemAt(0).getType() == Type.STRING) {
 						xpathExprString = args[6].getStringValue();
 					} else if (args[6].itemAt(0).getType() == 1) {
 						final Node certificateDetailsNode = ((NodeValue) args[6].itemAt(0)).getNode();
@@ -233,7 +234,9 @@ public Sequence eval(final Sequence[] args, final Sequence contextSequence) thro
 
 				// signature with 8 arguments
 				if (args.length == 8) {
-					xpathExprString = args[6].getStringValue();
+					if (args[6].getItemCount() > 0) {
+						xpathExprString = args[6].getStringValue();
+					}
 					final Node certificateDetailsNode = ((NodeValue) args[7].itemAt(0)).getNode();
 					// get the certificate details
 					certificateDetails = getDigitalCertificateDetails(certificateDetails, certificateDetailsNode);

src/main/java/org/expath/exist/crypto/encrypt/EncryptionFunctions.java

@@ -139,9 +139,7 @@ private Sequence encrypt(byte[] data, CryptType encryptType, String secretKey, S
 			LOG.debug("encrypt result = {}", result);
 
 			return new StringValue(result);
-		} catch (
-
-		CryptoException e) {
+		} catch (final CryptoException e) {
 			throw new EXpathCryptoException(this, e.getCryptoError());
 		} catch (IOException e) {
 			throw new EXpathCryptoException(this, e);