Ipv6 host validation support

src/aws-cpp-sdk-core/source/utils/DNS.cpp

@@ -5,7 +5,7 @@
 
 #include <aws/core/utils/DNS.h>
 #include <aws/core/utils/StringUtils.h>
-
+#include <cctype>
 namespace Aws
 {
     namespace Utils
@@ -40,6 +40,65 @@ namespace Aws
             return true;
         }
 
+        bool isValidIPv6Segment(const std::string& segment) {
+            if (segment.empty() || segment.length() > 4){
+                return false;
+            }
+            return std::all_of(segment.begin(), segment.end(), isxdigit);
+        }
+
+        //The assumption is this is only called with the domain part of uri
+        bool isValidIpv6Host(const Aws::String& host)
+        {
+            if(host.empty())
+            {
+                return false;
+            }
+            size_t segmentCount = 1;
+            bool doubleColonFound = false;
+            size_t labelStart = 0;
+
+            for(size_t i = 0; i < host.length(); ++i)
+            {
+                if(host[i] == ':')
+                {
+                    // double colon check
+                    if(i + 1 < host.length() && host[i+1] == ':')
+                    {
+                        if(doubleColonFound) {
+                            return false;
+                        }
+                        doubleColonFound = true;
+                        ++i;
+                    }
+                    // single colon segment
+                    else
+                    {
+                        if(!isValidIPv6Segment(host.substr(labelStart, i - labelStart))) {
+                            return false;
+                        }
+                        ++segmentCount;
+                    }
+                    labelStart = i + 1;
+                }
+                // no dots in ipv6
+                else if(host[i] == '.')
+                {
+                    return false;
+                }
+            }
+
+            // Handle last segment
+            if(labelStart < host.length())
+            {
+                if(!isValidIPv6Segment(host.substr(labelStart))){
+                    return false;
+                }
+            }
+            // Check if we have 8 segments or less with one double colon
+            return (doubleColonFound && segmentCount < 8) || (!doubleColonFound && segmentCount == 8);
+        }
+
         bool IsValidHost(const Aws::String& host)
         {
             // Valid DNS hostnames are composed of valid DNS labels separated by a period.
@@ -49,7 +108,7 @@ namespace Aws
                 return false;
             }
 
-            return !std::any_of(labels.begin(), labels.end(), [](const Aws::String& label){ return !IsValidDnsLabel(label); });
+            return !std::any_of(labels.begin(), labels.end(), [](const Aws::String& label){ return !IsValidDnsLabel(label); }) || isValidIpv6Host(host);
         }
     }
 }

tests/aws-cpp-sdk-core-tests/utils/DNSTest.cpp

@@ -61,3 +61,29 @@ TEST_F(DnsTest, TestHost)
     ASSERT_FALSE(IsValidHost("0123456789012345678901234567890123456789012345678901234567890123.com")); // 64 characters
 
 }
+
+TEST_F(DnsTest, TestIPV6)
+{
+    Aws::Vector< std::pair<Aws::String, bool> > inputs = {
+        {"2001:0db8:85a3:0000:0000:8a2e:0370:7334", true},
+        {"2001:DB8:85A3::8A2E:370:7334", true},
+        {"::ffff", true},
+        {"::", true},
+        {"ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff",true},
+        {"2001:db8:85a3:0:0:8a2e:370:7334",true},
+        {"2001:db8:85a3:0000:0000:8a2e:0370:7334:1", false},
+        {"2001:db8:85a3:0000", false},
+        {"2001:0db8:85a3:0000:0000:8a2e:0370:7334:", false},
+        {"g001:0db8:85a3:0000:0000:8a2e:0370:7334", false},
+        {"2001:db8::85a3::1", false},
+        {":2001:db8:85a3:0000:0000:8a2e:0370:7334", false},
+        {"0:0:0:0:0:0:0:0", true},
+        {"2001:db8::", true}
+    };
+
+    for(auto t : inputs)
+    {
+        ASSERT_EQ(IsValidHost(t.first), t.second);
+    }
+
+}