Merge branch 'agaurav77-84'

lib/ssh_scan/crypto.rb

@@ -0,0 +1,38 @@
+require 'openssl'
+
+module SSHScan
+  module Crypto
+    class PublicKey
+      def initialize(key)
+        @key = key
+        @supported = check_supported
+        if @key.is_a?(OpenSSL::PKey::RSA)
+          @data_string = OpenSSL::ASN1::Sequence([
+           OpenSSL::ASN1::Integer.new(@key.public_key.n),
+           OpenSSL::ASN1::Integer.new(@key.public_key.e)
+          ])
+        end
+      end
+
+      def check_supported
+        @key and @key.is_a?(OpenSSL::PKey::RSA)
+      end
+
+      def is_supported?
+        @supported
+      end
+
+      def fingerprint_md5
+        OpenSSL::Digest::MD5.hexdigest(@data_string.to_der).scan(/../).join(':')
+      end
+
+      def fingerprint_sha1
+        OpenSSL::Digest::SHA1.hexdigest(@data_string.to_der).scan(/../).join(':')
+      end
+
+      def fingerprint_sha256
+        OpenSSL::Digest::SHA256.hexdigest(@data_string.to_der).scan(/../).join(':')
+      end
+    end
+  end
+end

lib/ssh_scan/scan_engine.rb

@@ -1,5 +1,6 @@
 require 'socket'
 require 'ssh_scan/client'
+require 'ssh_scan/crypto'
 require 'net/ssh'
 
 module SSHScan
@@ -65,21 +66,12 @@ def scan_target(socket, opts)
           raise e
         end
       else
-        #only supporting RSA for the moment
-        if host_key.is_a?(OpenSSL::PKey::RSA)
-          data_string = OpenSSL::ASN1::Sequence([
-           OpenSSL::ASN1::Integer.new(host_key.public_key.n),
-           OpenSSL::ASN1::Integer.new(host_key.public_key.e)
-          ])
-
-          fingerprint_md5 = OpenSSL::Digest::MD5.hexdigest(data_string.to_der).scan(/../).join(':')
-          fingerprint_sha1 = OpenSSL::Digest::SHA1.hexdigest(data_string.to_der).scan(/../).join(':')
-          fingerprint_sha256 = OpenSSL::Digest::SHA256.hexdigest(data_string.to_der).scan(/../).join(':')
-
+        pkey = SSHScan::Crypto::PublicKey.new(host_key)
+        if pkey.is_supported?
           result['fingerprints'] = {
-           "md5" => fingerprint_md5,
-           "sha1" => fingerprint_sha1,
-           "sha256" => fingerprint_sha256,
+            "md5" => pkey.fingerprint_md5,
+            "sha1" => pkey.fingerprint_sha1,
+            "sha256" => pkey.fingerprint_sha256,
           }
         end
       end

spec/ssh_scan/crypto_spec.rb

@@ -0,0 +1,31 @@
+require 'rspec'
+require 'ssh_scan/crypto'
+
+describe SSHScan::Crypto::PublicKey do
+  context "when generating fingerprints" do
+    it "should generate fingerprints for RSA correctly" do
+      n = 23632077324088144501092249680419323739801323600158813273568324482496307162318789721613792811401614942684260029660183874482776189498160448960310809637920685817778474704815582955313091633951038693905769728720185981622436072311236535004735349701960456244504965079638695753583677574707979833350935481548040866639919163639882690698478860068170762157813993121946939288799580004748275380656448478194991959145948158111224324849043207283358199193762047855464042037676265770354633294836412162886761428400000041644966377946401322325086274306679173170324632010743865598861975638899651525149666813619204319259532409320007544358571
+      e = 65537
+      md5_expected = "82:13:2b:db:4d:5e:2d:e2:1b:b3:2b:25:eb:0b:9a:ed"
+      sha1_expected = "19:42:84:7a:b3:5c:1b:85:ee:81:9f:a8:19:e2:64:dc:44:81:a2:61"
+      sha256_expected = "ae:fb:8b:a2:e3:89:23:d2:12:fb:75:49:24:ed:f0:50:07:5f:c9:76:2c:14:ee:51:ae:96:e4:85:1d:6d:e7:79"
+      publickey = OpenSSL::ASN1::Sequence.new([
+        OpenSSL::ASN1::Integer.new(n),
+        OpenSSL::ASN1::Integer.new(e)
+      ])
+      sequence = OpenSSL::ASN1::Sequence.new([
+        OpenSSL::ASN1::Sequence.new([
+          OpenSSL::ASN1::ObjectId.new("rsaEncryption"),
+          OpenSSL::ASN1::Null.new(nil)
+        ]),
+        OpenSSL::ASN1::BitString.new(publickey.to_der)
+      ])
+      key = OpenSSL::PKey::RSA.new(sequence.to_der)
+      host_key = SSHScan::Crypto::PublicKey.new(key)
+      expect(host_key.is_supported?).to eql(true)
+      expect(host_key.fingerprint_md5).to eql(md5_expected)
+      expect(host_key.fingerprint_sha1).to eql(sha1_expected)
+      expect(host_key.fingerprint_sha256).to eql(sha256_expected)
+    end
+  end
+end