LibCrypto: Fix broken CTR mode, implement RFC 3686 Test Vectors

2 files changed, 241 insertions, 12 deletions

diff --git a/Libraries/LibCrypto/Cipher/Mode/CTR.h b/Libraries/LibCrypto/Cipher/Mode/CTR.h
index 8a6ceb38d5..07e4e1a0f4 100644
--- a/Libraries/LibCrypto/Cipher/Mode/CTR.h
+++ b/Libraries/LibCrypto/Cipher/Mode/CTR.h
@@ -82,8 +82,9 @@ namespace Cipher {
  *
  * Due to this plethora of mutually-incompatible counters,
  * the method of counting should be a template parameter.
- * This currently implements BIGINT_MIXEDENDIAN_INCR_0, which is not used
- * anywhere else.
+ * This currently implements BIGINT_INCR_0, which means perfect
+ * interoperability with openssl. The test vectors from RFC 3686 just need to be
+ * incremented by 1.
  * TODO: Implement other counters?
  */
 
@@ -112,6 +113,8 @@ public:
 
     virtual Optional<ByteBuffer> encrypt(const ByteBuffer& in, ByteBuffer& out, Optional<ByteBuffer> ivec = {}) override
     {
+        // Our interpretation of "ivec" is what AES-CTR
+        // would define as nonce + IV + 4 zero bytes.
         return this->encrypt_or_stream(&in, out, ivec);
     }
 
@@ -129,20 +132,17 @@ public:
     }
 
 private:
-    static ByteBuffer increment(const ByteBuffer& in)
+    static void increment_inplace(ByteBuffer& in)
     {
-        ByteBuffer new_buffer(in);
-        size_t* num_view = (size_t*)new_buffer.data();
-
-        for (size_t i = 0; i < in.size() / sizeof(size_t); ++i) {
-            if (num_view[i] == (size_t)-1) {
-                num_view[i] = 0;
+        for (size_t i = in.size(); i > 0;) {
+            --i;
+            if (in[i] == (u8)-1) {
+                in[i] = 0;
             } else {
-                num_view[i]++;
+                in[i]++;
                 break;
             }
         }
-        return new_buffer;
     }
 
     Optional<ByteBuffer> encrypt_or_stream(const ByteBuffer* in, ByteBuffer& out, Optional<ByteBuffer> ivec)
@@ -178,7 +178,7 @@ private:
             auto write_size = min(block_size, length);
             out.overwrite(offset, block.get().data(), write_size);
 
-            iv = increment(iv);
+            increment_inplace(iv);
             length -= write_size;
             offset += write_size;
         }
diff --git a/Userland/test-crypto.cpp b/Userland/test-crypto.cpp
index 629e09d4c6..4d6eea100b 100644
--- a/Userland/test-crypto.cpp
+++ b/Userland/test-crypto.cpp
@@ -68,6 +68,7 @@ constexpr const char* DEFAULT_SERVER { "www.google.com" };
 // listAllTests
 // Cipher
 int aes_cbc_tests();
+int aes_ctr_tests();
 
 // Hash
 int md5_tests();
@@ -368,9 +369,11 @@ auto main(int argc, char** argv) -> int
     if (mode_sv == "test") {
         encrypting = true;
         aes_cbc_tests();
+        aes_ctr_tests();
 
         encrypting = false;
         aes_cbc_tests();
+        aes_ctr_tests();
 
         md5_tests();
         sha1_tests();
@@ -458,6 +461,9 @@ ByteBuffer operator""_b(const char* string, size_t length)
 void aes_cbc_test_name();
 void aes_cbc_test_encrypt();
 void aes_cbc_test_decrypt();
+void aes_ctr_test_name();
+void aes_ctr_test_encrypt();
+void aes_ctr_test_decrypt();
 
 void md5_test_name();
 void md5_test_hash();
@@ -644,6 +650,229 @@ void aes_cbc_test_decrypt()
     // TODO: Test non-CMS padding options
 }
 
+int aes_ctr_tests()
+{
+    aes_ctr_test_name();
+    if (encrypting) {
+        aes_ctr_test_encrypt();
+    } else {
+        aes_ctr_test_decrypt();
+    }
+
+    return g_some_test_failed ? 1 : 0;
+}
+
+void aes_ctr_test_name()
+{
+    I_TEST((AES CTR class name));
+    Crypto::Cipher::AESCipher::CTRMode cipher("WellHelloFriends"_b, 128, Crypto::Cipher::Intent::Encryption);
+    if (cipher.class_name() != "AES_CTR")
+        FAIL(Invalid class name);
+    else
+        PASS;
+}
+
+#define AS_BB(x) (ByteBuffer::wrap((x), sizeof((x)) / sizeof((x)[0])))
+void aes_ctr_test_encrypt()
+{
+    auto test_it = [](auto key, auto ivec, auto in, auto out_expected) {
+        // nonce is already included in ivec.
+        Crypto::Cipher::AESCipher::CTRMode cipher(key, 8 * key.size(), Crypto::Cipher::Intent::Encryption);
+        ByteBuffer out_actual = ByteBuffer::create_zeroed(in.size());
+        ByteBuffer final_ivec = cipher.encrypt(in, out_actual, ivec).value();
+        if (out_expected.size() != out_actual.size()) {
+            FAIL(size mismatch);
+            printf("Expected %zu bytes but got %zu\n", out_expected.size(), out_actual.size());
+            print_buffer(out_actual, Crypto::Cipher::AESCipher::block_size());
+        } else if (memcmp(out_expected.data(), out_actual.data(), out_expected.size()) != 0) {
+            FAIL(invalid data);
+            print_buffer(out_actual, Crypto::Cipher::AESCipher::block_size());
+        } else
+            PASS;
+    };
+    // From RFC 3686, Section 6
+    {
+        // Test Vector #1
+        I_TEST((AES CTR 16 octets with 128 bit key | Encrypt))
+        u8 key[] {
+            0xae, 0x68, 0x52, 0xf8, 0x12, 0x10, 0x67, 0xcc, 0x4b, 0xf7, 0xa5, 0x76, 0x55, 0x77, 0xf3, 0x9e
+        };
+        u8 ivec[] {
+            0x00, 0x00, 0x00, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x53, 0x69, 0x6e, 0x67, 0x6c, 0x65, 0x20, 0x62, 0x6c, 0x6f, 0x63, 0x6b, 0x20, 0x6d, 0x73, 0x67
+        };
+        u8 out[] {
+            0xe4, 0x09, 0x5d, 0x4f, 0xb7, 0xa7, 0xb3, 0x79, 0x2d, 0x61, 0x75, 0xa3, 0x26, 0x13, 0x11, 0xb8
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #2
+        I_TEST((AES CTR 32 octets with 128 bit key | Encrypt))
+        u8 key[] {
+            0x7e, 0x24, 0x06, 0x78, 0x17, 0xfa, 0xe0, 0xd7, 0x43, 0xd6, 0xce, 0x1f, 0x32, 0x53, 0x91, 0x63
+        };
+        u8 ivec[] {
+            0x00, 0x6c, 0xb6, 0xdb, 0xc0, 0x54, 0x3b, 0x59, 0xda, 0x48, 0xd9, 0x0b, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f
+        };
+        u8 out[] {
+            0x51, 0x04, 0xa1, 0x06, 0x16, 0x8a, 0x72, 0xd9, 0x79, 0x0d, 0x41, 0xee, 0x8e, 0xda, 0xd3, 0x88,
+            0xeb, 0x2e, 0x1e, 0xfc, 0x46, 0xda, 0x57, 0xc8, 0xfc, 0xe6, 0x30, 0xdf, 0x91, 0x41, 0xbe, 0x28
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #3
+        I_TEST((AES CTR 36 octets with 128 bit key | Encrypt))
+        u8 key[] {
+            0x76, 0x91, 0xbe, 0x03, 0x5e, 0x50, 0x20, 0xa8, 0xac, 0x6e, 0x61, 0x85, 0x29, 0xf9, 0xa0, 0xdc
+        };
+        u8 ivec[] {
+            0x00, 0xe0, 0x01, 0x7b, 0x27, 0x77, 0x7f, 0x3f, 0x4a, 0x17, 0x86, 0xf0, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23
+        };
+        u8 out[] {
+            0xc1, 0xcf, 0x48, 0xa8, 0x9f, 0x2f, 0xfd, 0xd9, 0xcf, 0x46, 0x52, 0xe9, 0xef, 0xdb, 0x72, 0xd7, 0x45, 0x40, 0xa4, 0x2b, 0xde, 0x6d, 0x78, 0x36, 0xd5, 0x9a, 0x5c, 0xea, 0xae, 0xf3, 0x10, 0x53, 0x25, 0xb2, 0x07, 0x2f
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #4
+        I_TEST((AES CTR 16 octets with 192 bit key | Encrypt))
+        u8 key[] {
+            0x16, 0xaf, 0x5b, 0x14, 0x5f, 0xc9, 0xf5, 0x79, 0xc1, 0x75, 0xf9, 0x3e, 0x3b, 0xfb, 0x0e, 0xed, 0x86, 0x3d, 0x06, 0xcc, 0xfd, 0xb7, 0x85, 0x15
+        };
+        u8 ivec[] {
+            0x00, 0x00, 0x00, 0x48, 0x36, 0x73, 0x3c, 0x14, 0x7d, 0x6d, 0x93, 0xcb, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x53, 0x69, 0x6e, 0x67, 0x6c, 0x65, 0x20, 0x62, 0x6c, 0x6f, 0x63, 0x6b, 0x20, 0x6d, 0x73, 0x67
+        };
+        u8 out[] {
+            0x4b, 0x55, 0x38, 0x4f, 0xe2, 0x59, 0xc9, 0xc8, 0x4e, 0x79, 0x35, 0xa0, 0x03, 0xcb, 0xe9, 0x28
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #5
+        I_TEST((AES CTR 32 octets with 192 bit key | Encrypt))
+        u8 key[] {
+            0x7c, 0x5c, 0xb2, 0x40, 0x1b, 0x3d, 0xc3, 0x3c, 0x19, 0xe7, 0x34, 0x08, 0x19, 0xe0, 0xf6, 0x9c, 0x67, 0x8c, 0x3d, 0xb8, 0xe6, 0xf6, 0xa9, 0x1a
+        };
+        u8 ivec[] {
+            0x00, 0x96, 0xb0, 0x3b, 0x02, 0x0c, 0x6e, 0xad, 0xc2, 0xcb, 0x50, 0x0d, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f
+        };
+        u8 out[] {
+            0x45, 0x32, 0x43, 0xfc, 0x60, 0x9b, 0x23, 0x32, 0x7e, 0xdf, 0xaa, 0xfa, 0x71, 0x31, 0xcd, 0x9f, 0x84, 0x90, 0x70, 0x1c, 0x5a, 0xd4, 0xa7, 0x9c, 0xfc, 0x1f, 0xe0, 0xff, 0x42, 0xf4, 0xfb, 0x00
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #6
+        I_TEST((AES CTR 36 octets with 192 bit key | Encrypt))
+        u8 key[] {
+            0x02, 0xbf, 0x39, 0x1e, 0xe8, 0xec, 0xb1, 0x59, 0xb9, 0x59, 0x61, 0x7b, 0x09, 0x65, 0x27, 0x9b, 0xf5, 0x9b, 0x60, 0xa7, 0x86, 0xd3, 0xe0, 0xfe
+        };
+        u8 ivec[] {
+            0x00, 0x07, 0xbd, 0xfd, 0x5c, 0xbd, 0x60, 0x27, 0x8d, 0xcc, 0x09, 0x12, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23
+        };
+        u8 out[] {
+            0x96, 0x89, 0x3f, 0xc5, 0x5e, 0x5c, 0x72, 0x2f, 0x54, 0x0b, 0x7d, 0xd1, 0xdd, 0xf7, 0xe7, 0x58, 0xd2, 0x88, 0xbc, 0x95, 0xc6, 0x91, 0x65, 0x88, 0x45, 0x36, 0xc8, 0x11, 0x66, 0x2f, 0x21, 0x88, 0xab, 0xee, 0x09, 0x35
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #7
+        I_TEST((AES CTR 16 octets with 256 bit key | Encrypt))
+        u8 key[] {
+            0x77, 0x6b, 0xef, 0xf2, 0x85, 0x1d, 0xb0, 0x6f, 0x4c, 0x8a, 0x05, 0x42, 0xc8, 0x69, 0x6f, 0x6c, 0x6a, 0x81, 0xaf, 0x1e, 0xec, 0x96, 0xb4, 0xd3, 0x7f, 0xc1, 0xd6, 0x89, 0xe6, 0xc1, 0xc1, 0x04
+        };
+        u8 ivec[] {
+            0x00, 0x00, 0x00, 0x60, 0xdb, 0x56, 0x72, 0xc9, 0x7a, 0xa8, 0xf0, 0xb2, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x53, 0x69, 0x6e, 0x67, 0x6c, 0x65, 0x20, 0x62, 0x6c, 0x6f, 0x63, 0x6b, 0x20, 0x6d, 0x73, 0x67
+        };
+        u8 out[] {
+            0x14, 0x5a, 0xd0, 0x1d, 0xbf, 0x82, 0x4e, 0xc7, 0x56, 0x08, 0x63, 0xdc, 0x71, 0xe3, 0xe0, 0xc0
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #8
+        I_TEST((AES CTR 32 octets with 256 bit key | Encrypt))
+        u8 key[] {
+            0xf6, 0xd6, 0x6d, 0x6b, 0xd5, 0x2d, 0x59, 0xbb, 0x07, 0x96, 0x36, 0x58, 0x79, 0xef, 0xf8, 0x86, 0xc6, 0x6d, 0xd5, 0x1a, 0x5b, 0x6a, 0x99, 0x74, 0x4b, 0x50, 0x59, 0x0c, 0x87, 0xa2, 0x38, 0x84
+        };
+        u8 ivec[] {
+            0x00, 0xfa, 0xac, 0x24, 0xc1, 0x58, 0x5e, 0xf1, 0x5a, 0x43, 0xd8, 0x75, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f
+        };
+        u8 out[] {
+            0xf0, 0x5e, 0x23, 0x1b, 0x38, 0x94, 0x61, 0x2c, 0x49, 0xee, 0x00, 0x0b, 0x80, 0x4e, 0xb2, 0xa9, 0xb8, 0x30, 0x6b, 0x50, 0x8f, 0x83, 0x9d, 0x6a, 0x55, 0x30, 0x83, 0x1d, 0x93, 0x44, 0xaf, 0x1c
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    {
+        // Test Vector #9
+        I_TEST((AES CTR 36 octets with 256 bit key | Encrypt))
+        u8 key[] {
+            0xff, 0x7a, 0x61, 0x7c, 0xe6, 0x91, 0x48, 0xe4, 0xf1, 0x72, 0x6e, 0x2f, 0x43, 0x58, 0x1d, 0xe2, 0xaa, 0x62, 0xd9, 0xf8, 0x05, 0x53, 0x2e, 0xdf, 0xf1, 0xee, 0xd6, 0x87, 0xfb, 0x54, 0x15, 0x3d
+        };
+        u8 ivec[] {
+            0x00, 0x1c, 0xc5, 0xb7, 0x51, 0xa5, 0x1d, 0x70, 0xa1, 0xc1, 0x11, 0x48, 0x00, 0x00, 0x00, 0x00 + 1 // See CTR.h
+        };
+        u8 in[] {
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23
+        };
+        u8 out[] {
+            0xeb, 0x6c, 0x52, 0x82, 0x1d, 0x0b, 0xbb, 0xf7, 0xce, 0x75, 0x94, 0x46, 0x2a, 0xca, 0x4f, 0xaa, 0xb4, 0x07, 0xdf, 0x86, 0x65, 0x69, 0xfd, 0x07, 0xf4, 0x8c, 0xc0, 0xb5, 0x83, 0xd6, 0x07, 0x1f, 0x1e, 0xc0, 0xe6, 0xb8
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+    // Manual test case
+    {
+        // This test checks whether counter overflow crashes.
+        I_TEST((AES CTR 36 octets with 256 bit key, high counter | Encrypt))
+        u8 key[] {
+            0xff, 0x7a, 0x61, 0x7c, 0xe6, 0x91, 0x48, 0xe4, 0xf1, 0x72, 0x6e, 0x2f, 0x43, 0x58, 0x1d, 0xe2, 0xaa, 0x62, 0xd9, 0xf8, 0x05, 0x53, 0x2e, 0xdf, 0xf1, 0xee, 0xd6, 0x87, 0xfb, 0x54, 0x15, 0x3d
+        };
+        u8 ivec[] {
+            0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+        };
+        u8 in[] {
+            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23
+        };
+        u8 out[] {
+            // Pasted from the output. The actual success condition is
+            // not crashing when incrementing the counter.
+            0x6e, 0x8c, 0xfc, 0x59, 0x08, 0xa8, 0xc0, 0xf1, 0xe6, 0x85, 0x96, 0xe9, 0xc5, 0x40, 0xb6, 0x8b, 0xfe, 0x28, 0x72, 0xe2, 0x24, 0x11, 0x7e, 0x59, 0xef, 0xac, 0x5c, 0xe1, 0x06, 0x89, 0x09, 0xab, 0xf8, 0x90, 0x1c, 0x66
+        };
+        test_it(AS_BB(key), AS_BB(ivec), AS_BB(in), AS_BB(out));
+    }
+}
+
+void aes_ctr_test_decrypt()
+{
+    // FIXME Test not implemented yet
+    // Also, CTR implementation not done yet, even though it's trivial: Just ignore "intent".
+}
+
 int md5_tests()
 {
     md5_test_name();