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Diffstat (limited to 'crypto/aead_openssl.cc')
-rw-r--r-- | crypto/aead_openssl.cc | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/crypto/aead_openssl.cc b/crypto/aead_openssl.cc new file mode 100644 index 0000000..e32168a --- /dev/null +++ b/crypto/aead_openssl.cc @@ -0,0 +1,125 @@ +// Copyright 2015 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "crypto/aead_openssl.h" + +#if defined(USE_OPENSSL) + +#include <openssl/aes.h> +#include <openssl/evp.h> +#include <string> + +#include "base/basictypes.h" +#include "base/strings/string_util.h" +#include "crypto/openssl_util.h" + +namespace crypto { + +Aead::Aead(AeadAlgorithm algorithm) : key_(nullptr) { + EnsureOpenSSLInit(); + switch (algorithm) { + case AES_128_CTR_HMAC_SHA256: + aead_ = EVP_aead_aes_128_ctr_hmac_sha256(); + break; + } +} + +Aead::~Aead() { +} + +void Aead::Init(const std::string* key) { + DCHECK(!key_); + DCHECK_EQ(KeyLength(), key->size()); + key_ = key; +} + +bool Aead::Seal(const base::StringPiece& plaintext, + const base::StringPiece& nonce, + const base::StringPiece& additional_data, + std::string* ciphertext) const { + DCHECK(key_); + DCHECK_EQ(NonceLength(), nonce.size()); + EVP_AEAD_CTX ctx; + + if (!EVP_AEAD_CTX_init(&ctx, aead_, + reinterpret_cast<const uint8*>(key_->data()), + key_->size(), EVP_AEAD_DEFAULT_TAG_LENGTH, nullptr)) { + return false; + } + + std::string result; + const size_t max_output_length = + EVP_AEAD_max_overhead(aead_) + plaintext.size(); + size_t output_length; + uint8* out_ptr = + reinterpret_cast<uint8*>(WriteInto(&result, max_output_length + 1)); + + if (!EVP_AEAD_CTX_seal( + &ctx, out_ptr, &output_length, max_output_length, + reinterpret_cast<const uint8*>(nonce.data()), nonce.size(), + reinterpret_cast<const uint8*>(plaintext.data()), plaintext.size(), + reinterpret_cast<const uint8*>(additional_data.data()), + additional_data.size())) { + EVP_AEAD_CTX_cleanup(&ctx); + return false; + } + + DCHECK_LE(output_length, max_output_length); + result.resize(output_length); + + ciphertext->swap(result); + EVP_AEAD_CTX_cleanup(&ctx); + + return true; +} + +bool Aead::Open(const base::StringPiece& ciphertext, + const base::StringPiece& nonce, + const base::StringPiece& additional_data, + std::string* plaintext) const { + DCHECK(key_); + EVP_AEAD_CTX ctx; + + if (!EVP_AEAD_CTX_init(&ctx, aead_, + reinterpret_cast<const uint8*>(key_->data()), + key_->size(), EVP_AEAD_DEFAULT_TAG_LENGTH, nullptr)) { + return false; + } + + std::string result; + const size_t max_output_length = ciphertext.size(); + size_t output_length; + uint8* out_ptr = + reinterpret_cast<uint8*>(WriteInto(&result, max_output_length + 1)); + + if (!EVP_AEAD_CTX_open( + &ctx, out_ptr, &output_length, max_output_length, + reinterpret_cast<const uint8*>(nonce.data()), nonce.size(), + reinterpret_cast<const uint8*>(ciphertext.data()), ciphertext.size(), + reinterpret_cast<const uint8*>(additional_data.data()), + additional_data.size())) { + EVP_AEAD_CTX_cleanup(&ctx); + return false; + } + + DCHECK_LE(output_length, max_output_length); + result.resize(output_length); + + plaintext->swap(result); + EVP_AEAD_CTX_cleanup(&ctx); + + return true; +} + +size_t Aead::KeyLength() const { + return EVP_AEAD_key_length(aead_); +} + +size_t Aead::NonceLength() const { + return EVP_AEAD_nonce_length(aead_); +} + +} // namespace + +#endif |