From 4d8bce227c85ef4d1f8b794a8c96a7b23e4cf357 Mon Sep 17 00:00:00 2001
From: Spencer McIntyre <zeroSteiner@gmail.com>
Date: Mon, 30 Mar 2020 14:42:53 -0400
Subject: [ruby/openssl] Define Cipher #ccm_data_len= for CCM mode ciphers

Allow specifying just length to #update

CCM mode ciphers need to specify the total plaintext or ciphertext
length to EVP_CipherUpdate.

Update the link to the tests file

Define Cipher#ccm_data_len= for CCM mode ciphers

Add a unit test for CCM mode

Also check CCM is authenticated when testing

https://github.com/ruby/openssl/commit/bb3816953b
---
 test/openssl/test_cipher.rb | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

(limited to 'test/openssl/test_cipher.rb')

diff --git a/test/openssl/test_cipher.rb b/test/openssl/test_cipher.rb
index 178f5aba0e..65b36dd180 100644
--- a/test/openssl/test_cipher.rb
+++ b/test/openssl/test_cipher.rb
@@ -174,6 +174,48 @@ class OpenSSL::TestCipher < OpenSSL::TestCase
     assert_not_predicate(cipher, :authenticated?)
   end
 
+  def test_aes_ccm
+    # RFC 3610 Section 8, Test Case 1
+    key = ["c0c1c2c3c4c5c6c7c8c9cacbcccdcecf"].pack("H*")
+    iv =  ["00000003020100a0a1a2a3a4a5"].pack("H*")
+    aad = ["0001020304050607"].pack("H*")
+    pt =  ["08090a0b0c0d0e0f101112131415161718191a1b1c1d1e"].pack("H*")
+    ct =  ["588c979a61c663d2f066d0c2c0f989806d5f6b61dac384"].pack("H*")
+    tag = ["17e8d12cfdf926e0"].pack("H*")
+
+    kwargs = {auth_tag_len: 8, iv_len: 13, key: key, iv: iv}
+    cipher = new_encryptor("aes-128-ccm", **kwargs, ccm_data_len: pt.length, auth_data: aad)
+    assert_equal ct, cipher.update(pt) << cipher.final
+    assert_equal tag, cipher.auth_tag
+    cipher = new_decryptor("aes-128-ccm", **kwargs, ccm_data_len: ct.length, auth_tag: tag, auth_data: aad)
+    assert_equal pt, cipher.update(ct) << cipher.final
+
+    # truncated tag is accepted
+    cipher = new_encryptor("aes-128-ccm", **kwargs, ccm_data_len: pt.length, auth_data: aad)
+    assert_equal ct, cipher.update(pt) << cipher.final
+    assert_equal tag[0, 8], cipher.auth_tag(8)
+    cipher = new_decryptor("aes-128-ccm", **kwargs, ccm_data_len: ct.length, auth_tag: tag[0, 8], auth_data: aad)
+    assert_equal pt, cipher.update(ct) << cipher.final
+
+    # wrong tag is rejected
+    tag2 = tag.dup
+    tag2.setbyte(-1, (tag2.getbyte(-1) + 1) & 0xff)
+    cipher = new_decryptor("aes-128-ccm", **kwargs, ccm_data_len: ct.length, auth_tag: tag2, auth_data: aad)
+    assert_raise(OpenSSL::Cipher::CipherError) { cipher.update(ct) }
+
+    # wrong aad is rejected
+    aad2 = aad[0..-2] << aad[-1].succ
+    cipher = new_decryptor("aes-128-ccm", **kwargs, ccm_data_len: ct.length, auth_tag: tag, auth_data: aad2)
+    assert_raise(OpenSSL::Cipher::CipherError) { cipher.update(ct) }
+
+    # wrong ciphertext is rejected
+    ct2 = ct[0..-2] << ct[-1].succ
+    cipher = new_decryptor("aes-128-ccm", **kwargs, ccm_data_len: ct2.length, auth_tag: tag, auth_data: aad)
+    assert_raise(OpenSSL::Cipher::CipherError) { cipher.update(ct2) }
+  end if has_cipher?("aes-128-ccm") &&
+         OpenSSL::Cipher.new("aes-128-ccm").authenticated? &&
+         OpenSSL::OPENSSL_VERSION_NUMBER >= 0x10101000  # version >= v1.1.1
+
   def test_aes_gcm
     # GCM spec Appendix B Test Case 4
     key = ["feffe9928665731c6d6a8f9467308308"].pack("H*")
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