Add EVP AES-128 CFB128 support via decrepit.

Change-Id: I37a438b5b4b18d18756ba4aeb9f8548caa333981
Reviewed-on: https://boringssl-review.googlesource.com/20384
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

decrepit/CMakeLists.txt

@@ -3,6 +3,7 @@ include_directories(../include)
 add_subdirectory(bio)
 add_subdirectory(blowfish)
 add_subdirectory(cast)
+add_subdirectory(cfb)
 add_subdirectory(des)
 add_subdirectory(dh)
 add_subdirectory(dsa)
@@ -21,6 +22,7 @@ add_library(
   $<TARGET_OBJECTS:bio_decrepit>
   $<TARGET_OBJECTS:blowfish>
   $<TARGET_OBJECTS:cast>
+  $<TARGET_OBJECTS:cfb>
   $<TARGET_OBJECTS:des_decrepit>
   $<TARGET_OBJECTS:dh_decrepit>
   $<TARGET_OBJECTS:dsa_decrepit>
@@ -40,6 +42,7 @@ add_executable(
   decrepit_test
 
   ripemd/ripemd_test.cc
+  cfb/cfb_test.cc
 
   $<TARGET_OBJECTS:gtest_main>
   $<TARGET_OBJECTS:test_support>

decrepit/cfb/CMakeLists.txt

@@ -0,0 +1,9 @@
+include_directories(../../include)
+
+add_library(
+  cfb
+
+  OBJECT
+
+  cfb.c
+)

decrepit/cfb/cfb.c

@@ -0,0 +1,60 @@
+// Copyright (c) 2017, Google Inc.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/cipher.h>
+
+#include <string.h>
+
+#include <openssl/aes.h>
+#include <openssl/obj.h>
+
+#include "../../crypto/internal.h"
+
+typedef struct {
+  AES_KEY ks;
+} EVP_CFB_CTX;
+
+static int aes_cfb_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,
+                            const uint8_t *iv, int enc) {
+  if (key) {
+    EVP_CFB_CTX *cfb_ctx = ctx->cipher_data;
+    AES_set_encrypt_key(key, ctx->key_len * 8, &cfb_ctx->ks);
+  }
+
+  return 1;
+}
+
+static int aes_cfb128_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out,
+                             const uint8_t *in, size_t len) {
+  if (!out || !in) {
+    return 0;
+  }
+
+  EVP_CFB_CTX *cfb_ctx = ctx->cipher_data;
+  int num = ctx->num;
+  AES_cfb128_encrypt(in, out, len, &cfb_ctx->ks, ctx->iv, &num,
+                     ctx->encrypt ? AES_ENCRYPT : AES_DECRYPT);
+  ctx->num = num;
+
+  return 1;
+}
+
+static const EVP_CIPHER aes_128_cfb128 = {
+    NID_aes_128_cfb128,  1 /* block_size */,  16 /* key_size */,
+    16 /* iv_len */,     sizeof(EVP_CFB_CTX), EVP_CIPH_CFB_MODE,
+    NULL /* app_data */, aes_cfb_init_key,    aes_cfb128_cipher,
+    NULL /* cleanup */,  NULL /* ctrl */,
+};
+
+const EVP_CIPHER *EVP_aes_128_cfb128(void) { return &aes_128_cfb128; }

decrepit/cfb/cfb_test.cc

@@ -0,0 +1,91 @@
+// Copyright (c) 2017, Google Inc.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/cipher.h>
+
+#include <gtest/gtest.h>
+
+#include "../../crypto/internal.h"
+#include "../../crypto/test/test_util.h"
+
+
+struct CFBTestCase {
+  uint8_t key[16];
+  uint8_t iv[16];
+  uint8_t plaintext[16*4];
+  uint8_t ciphertext[16*4];
+};
+
+static const CFBTestCase kCFBTestCases[] = {
+  {
+    // This is the test case from
+    // http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38a.pdf,
+    // section F.3.13.
+    {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c},
+    {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
+    {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
+     0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
+     0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
+     0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10},
+    {0x3b, 0x3f, 0xd9, 0x2e, 0xb7, 0x2d, 0xad, 0x20, 0x33, 0x34, 0x49, 0xf8, 0xe8, 0x3c, 0xfb, 0x4a,
+     0xc8, 0xa6, 0x45, 0x37, 0xa0, 0xb3, 0xa9, 0x3f, 0xcd, 0xe3, 0xcd, 0xad, 0x9f, 0x1c, 0xe5, 0x8b,
+     0x26, 0x75, 0x1f, 0x67, 0xa3, 0xcb, 0xb1, 0x40, 0xb1, 0x80, 0x8c, 0xf1, 0x87, 0xa4, 0xf4, 0xdf,
+     0xc0, 0x4b, 0x05, 0x35, 0x7c, 0x5d, 0x1c, 0x0e, 0xea, 0xc4, 0xc6, 0x6f, 0x9f, 0xf7, 0xf2, 0xe6},
+  },
+};
+
+TEST(CFBTest, TestVectors) {
+  unsigned test_num = 0;
+  for (const auto &test : kCFBTestCases) {
+    test_num++;
+    SCOPED_TRACE(test_num);
+
+    const size_t input_len = sizeof(test.plaintext);
+    std::unique_ptr<uint8_t[]> out(new uint8_t[input_len]);
+
+    for (size_t stride = 1; stride <= input_len; stride++) {
+      bssl::ScopedEVP_CIPHER_CTX ctx;
+      ASSERT_TRUE(EVP_EncryptInit_ex(ctx.get(), EVP_aes_128_cfb128(), nullptr,
+                                     test.key, test.iv));
+
+      size_t done = 0;
+      while (done < input_len) {
+        size_t todo = stride;
+        if (todo > input_len - done) {
+          todo = input_len - done;
+        }
+
+        int out_bytes;
+        ASSERT_TRUE(EVP_EncryptUpdate(ctx.get(), out.get() + done, &out_bytes,
+                                      test.plaintext + done, todo));
+        ASSERT_EQ(static_cast<size_t>(out_bytes), todo);
+
+        done += todo;
+      }
+
+      EXPECT_EQ(Bytes(test.ciphertext), Bytes(out.get(), input_len));
+    }
+
+    bssl::ScopedEVP_CIPHER_CTX decrypt_ctx;
+    ASSERT_TRUE(EVP_DecryptInit_ex(decrypt_ctx.get(), EVP_aes_128_cfb128(),
+                                   nullptr, test.key, test.iv));
+
+    std::unique_ptr<uint8_t[]> plaintext(new uint8_t[input_len]);
+    int num_bytes;
+    ASSERT_TRUE(EVP_DecryptUpdate(decrypt_ctx.get(), plaintext.get(),
+                                  &num_bytes, out.get(), input_len));
+    EXPECT_EQ(static_cast<size_t>(num_bytes), input_len);
+    EXPECT_EQ(Bytes(test.plaintext), Bytes(plaintext.get(), input_len));
+  }
+}

include/openssl/cipher.h

@@ -410,6 +410,9 @@ OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_cbc(void);
 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_ctr(void);
 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_gcm(void);
 
+// EVP_aes_128_cfb128 is only available in decrepit.
+OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_cfb128(void);
+
 
 // Private functions.