Added comment field in HostEntry for end-of-line comments in known_hosts file (#517)

* Added comment field in HostEntry for end-of-line comments in known_hosts file.

* Also modified the getLine() method to return the comment, if it exists.

* Fixed implementation

* Add CODEOWNERS file

Co-authored-by: Jeroen van Erp <jeroen@hierynomus.com>

.github/CODEOWNERS

@@ -0,0 +1,2 @@
+* @hierynomus
+

src/main/java/net/schmizz/sshj/transport/verification/OpenSSHKnownHosts.java

@@ -199,24 +199,22 @@ public class OpenSSHKnownHosts
                 return new CommentEntry(line);
             }
 
-            final String[] split = line.split("\\s+");
+            final String trimmed = line.trim();
-            if(split.length < 3) {
+            int minComponents = 3;
+            if (trimmed.startsWith("@")) {
+                minComponents = 4;
+            }
+            String[] split = trimmed.split("\\s+", minComponents + 1); // Add 1 for optional comments
+            if(split.length < minComponents) {
                 log.error("Error reading entry `{}`", line);
                 return new BadHostEntry(line);
             }
-
             int i = 0;
-            if (split[i].isEmpty()) {
+
-                i++;
-            }
             final Marker marker = Marker.fromString(split[i]);
             if (marker != null) {
                 i++;
             }
-            if(split.length < i + 3) {
-                log.error("Error reading entry `{}`", line);
-                return new BadHostEntry(line);
-            }
             final String hostnames = split[i++];
             final String sType = split[i++];
 
@@ -234,6 +232,9 @@ public class OpenSSHKnownHosts
                 }
             } else if (isBits(sType)) {
                 type = KeyType.RSA;
+                minComponents += 1;
+                // re-split
+                split = trimmed.split("\\s+", minComponents + 1); // Add 1 for optional comments
                 // int bits = Integer.valueOf(sType);
                 final BigInteger e = new BigInteger(split[i++]);
                 final BigInteger n = new BigInteger(split[i++]);
@@ -249,7 +250,13 @@ public class OpenSSHKnownHosts
                 return new BadHostEntry(line);
             }
 
-            return new HostEntry(marker, hostnames, type, key);
+            final String comment;
+            if (i < split.length) {
+                comment = split[i++];
+            } else {
+                comment = null;
+            }
+            return new HostEntry(marker, hostnames, type, key, comment);
         }
 
         private boolean isBits(String type) {
@@ -330,13 +337,19 @@ public class OpenSSHKnownHosts
         private final String hostPart;
         protected final KeyType type;
         protected final PublicKey key;
+        private final String comment;
         private final KnownHostMatchers.HostMatcher matcher;
 
         public HostEntry(Marker marker, String hostPart, KeyType type, PublicKey key) throws SSHException {
+            this(marker, hostPart, type, key, "");
+        }
+
+        public HostEntry(Marker marker, String hostPart, KeyType type, PublicKey key, String comment) throws SSHException {
             this.marker = marker;
             this.hostPart = hostPart;
             this.type = type;
             this.key = key;
+            this.comment = comment;
             this.matcher = KnownHostMatchers.createMatcher(hostPart);
         }
 
@@ -373,6 +386,9 @@ public class OpenSSHKnownHosts
             line.append(getHostPart());
             line.append(" ").append(type.toString());
             line.append(" ").append(getKeyString(key));
+
+            if (!comment.isEmpty()) line.append(" ").append(comment);
+
             return line.toString();
         }
 
@@ -384,6 +400,10 @@ public class OpenSSHKnownHosts
         protected String getHostPart() {
             return hostPart;
         }
+
+        public String getComment() {
+            return comment;
+        }
     }
 
     public static class BadHostEntry implements KnownHostEntry {

src/test/groovy/com/hierynomus/sshj/transport/verification/OpenSSHKnownHostsSpec.groovy

@@ -116,6 +116,36 @@ host1 ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBL
         s << ["\n", "#comment\n"]
     }
 
+    @Unroll
+    def "should contain comment at end of line"() {
+        given:
+        def f = knownHosts(host)
+        when:
+        OpenSSHKnownHosts knownHosts = new OpenSSHKnownHosts(f)
+
+        then:
+        knownHosts.entries().size() == 1
+        def entry = knownHosts.entries().get(0)
+        entry instanceof OpenSSHKnownHosts.HostEntry
+        entry.comment == comment
+
+        where:
+        host << [
+"|1|F1E1KeoE/eEWhi10WpGv4OdiO6Y=|3988QV0VE8wmZL7suNrYQLITLCg= ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6P9Hlwdahh250jGZYKg2snRq2j2lFJVdKSHyxqbJiVy9VX9gTkN3K2MD48qyrYLYOyGs3vTttyUk+cK++JMzURWsrP4piby7LpeOT+3Iq8CQNj4gXZdcH9w15Vuk2qS11at6IsQPVHpKD9HGg9//EFUccI/4w06k4XXLm/IxOGUwj6I2AeWmEOL3aDi+fe07TTosSdLUD6INtR0cyKsg0zC7Da24ixoShT8Oy3x2MpR7CY3PQ1pUVmvPkr79VeA+4qV9F1JM09WdboAMZgWQZ+XrbtuBlGsyhpUHSCQOya+kOJ+bYryS+U7A+6nmTW3C9FX4FgFqTF89UHOC7V0zZQ== this is a comment",
+"test.com,1.1.1.1 2048 35 22017496617994656680820635966392838863613340434802393112245951008866692373218840197754553998457793202561151141246686162285550121243768846314646395880632789308110750881198697743542374668273149584280424505890648953477691795864456749782348425425954366277600319096366690719901119774784695056100331902394094537054256611668966698242432417382422091372756244612839068092471592121759862971414741954991375710930168229171638843329213652899594987626853020377726482288618521941129157643483558764875338089684351824791983007780922947554898825663693324944982594850256042689880090306493029526546183035567296830604572253312294059766327 single",
+"schmizz.net,69.163.155.180 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6P9Hlwdahh250jGZYKg2snRq2j2lFJVdKSHyxqbJiVy9VX9gTkN3K2MD48qyrYLYOyGs3vTttyUk+cK++JMzURWsrP4piby7LpeOT+3Iq8CQNj4gXZdcH9w15Vuk2qS11at6IsQPVHpKD9HGg9//EFUccI/4w06k4XXLm/IxOGUwj6I2AeWmEOL3aDi+fe07TTosSdLUD6INtR0cyKsg0zC7Da24ixoShT8Oy3x2MpR7CY3PQ1pUVmvPkr79VeA+4qV9F1JM09WdboAMZgWQZ+XrbtuBlGsyhpUHSCQOya+kOJ+bYryS+U7A+6nmTW3C9FX4FgFqTF89UHOC7V0zZQ==",
+"schmizz.net,69.163.155.180 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6P9Hlwdahh250jGZYKg2snRq2j2lFJVdKSHyxqbJiVy9VX9gTkN3K2MD48qyrYLYOyGs3vTttyUk+cK++JMzURWsrP4piby7LpeOT+3Iq8CQNj4gXZdcH9w15Vuk2qS11at6IsQPVHpKD9HGg9//EFUccI/4w06k4XXLm/IxOGUwj6I2AeWmEOL3aDi+fe07TTosSdLUD6INtR0cyKsg0zC7Da24ixoShT8Oy3x2MpR7CY3PQ1pUVmvPkr79VeA+4qV9F1JM09WdboAMZgWQZ+XrbtuBlGsyhpUHSCQOya+kOJ+bYryS+U7A+6nmTW3C9FX4FgFqTF89UHOC7V0zZQ== ",
+"schmizz.net,69.163.155.180 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6P9Hlwdahh250jGZYKg2snRq2j2lFJVdKSHyxqbJiVy9VX9gTkN3K2MD48qyrYLYOyGs3vTttyUk+cK++JMzURWsrP4piby7LpeOT+3Iq8CQNj4gXZdcH9w15Vuk2qS11at6IsQPVHpKD9HGg9//EFUccI/4w06k4XXLm/IxOGUwj6I2AeWmEOL3aDi+fe07TTosSdLUD6INtR0cyKsg0zC7Da24ixoShT8Oy3x2MpR7CY3PQ1pUVmvPkr79VeA+4qV9F1JM09WdboAMZgWQZ+XrbtuBlGsyhpUHSCQOya+kOJ+bYryS+U7A+6nmTW3C9FX4FgFqTF89UHOC7V0zZQ== extra   space"
+        ]
+        comment << [
+            "this is a comment",
+            "single",
+            null,
+            null,
+            "extra   space"
+        ]
+    }
+
     @Unroll
     def "should match any host name from multi-host line"() {
         given: