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-rw-r--r--doc/manual/cryptobox.rst4
-rw-r--r--src/lib/kdf/kdf.cpp4
-rw-r--r--src/lib/misc/cryptobox/cryptobox.cpp77
-rw-r--r--src/lib/pbkdf/pbkdf.cpp12
-rw-r--r--src/lib/pbkdf/pbkdf.h9
-rw-r--r--src/tests/test_cryptobox.cpp42
6 files changed, 82 insertions, 66 deletions
diff --git a/doc/manual/cryptobox.rst b/doc/manual/cryptobox.rst
index ea77eee5a..a3a0d02b0 100644
--- a/doc/manual/cryptobox.rst
+++ b/doc/manual/cryptobox.rst
@@ -11,6 +11,10 @@ This is a set of simple routines that encrypt some data using a
passphrase. There are defined in the header `cryptobox.h`, inside
namespace `Botan::CryptoBox`.
+It generates cipher and MAC keys using 8192 iterations of PBKDF2 with
+HMAC(SHA-512), then encrypts using Serpent in CTR mode and authenticates using a
+HMAC(SHA-512) mac of the ciphertext, truncated to 160 bits.
+
.. cpp:function:: std::string encrypt(const byte input[], size_t input_len, \
const std::string& passphrase, \
RandomNumberGenerator& rng)
diff --git a/src/lib/kdf/kdf.cpp b/src/lib/kdf/kdf.cpp
index f3d962c14..a1b0b91a9 100644
--- a/src/lib/kdf/kdf.cpp
+++ b/src/lib/kdf/kdf.cpp
@@ -221,9 +221,9 @@ std::unique_ptr<KDF>
KDF::create_or_throw(const std::string& algo,
const std::string& provider)
{
- if(auto bc = KDF::create(algo, provider))
+ if(auto kdf = KDF::create(algo, provider))
{
- return bc;
+ return kdf;
}
throw Lookup_Error("KDF", algo, provider);
}
diff --git a/src/lib/misc/cryptobox/cryptobox.cpp b/src/lib/misc/cryptobox/cryptobox.cpp
index 0ff6fe8f5..7551e21c1 100644
--- a/src/lib/misc/cryptobox/cryptobox.cpp
+++ b/src/lib/misc/cryptobox/cryptobox.cpp
@@ -35,7 +35,8 @@ const size_t MAC_OUTPUT_LEN = 20;
const size_t PBKDF_SALT_LEN = 10;
const size_t PBKDF_ITERATIONS = 8 * 1024;
-const size_t PBKDF_OUTPUT_LEN = CIPHER_KEY_LEN + CIPHER_IV_LEN + MAC_KEY_LEN;
+const size_t PBKDF_OUTPUT_LEN = CIPHER_KEY_LEN + MAC_KEY_LEN + CIPHER_IV_LEN;
+const size_t HEADER_LEN = VERSION_CODE_LEN + PBKDF_SALT_LEN + MAC_OUTPUT_LEN;
}
@@ -43,32 +44,6 @@ std::string encrypt(const uint8_t input[], size_t input_len,
const std::string& passphrase,
RandomNumberGenerator& rng)
{
- secure_vector<uint8_t> pbkdf_salt(PBKDF_SALT_LEN);
- rng.randomize(pbkdf_salt.data(), pbkdf_salt.size());
-
- PKCS5_PBKDF2 pbkdf(new HMAC(new SHA_512));
-
- OctetString master_key = pbkdf.derive_key(
- PBKDF_OUTPUT_LEN,
- passphrase,
- pbkdf_salt.data(),
- pbkdf_salt.size(),
- PBKDF_ITERATIONS);
-
- const uint8_t* mk = master_key.begin();
-
- SymmetricKey cipher_key(mk, CIPHER_KEY_LEN);
- SymmetricKey mac_key(&mk[CIPHER_KEY_LEN], MAC_KEY_LEN);
- InitializationVector iv(&mk[CIPHER_KEY_LEN + MAC_KEY_LEN], CIPHER_IV_LEN);
-
- Pipe pipe(get_cipher("Serpent/CTR-BE", cipher_key, iv, ENCRYPTION),
- new Fork(
- nullptr,
- new MAC_Filter(new HMAC(new SHA_512),
- mac_key, MAC_OUTPUT_LEN)));
-
- pipe.process_msg(input, input_len);
-
/*
Output format is:
version # (4 bytes)
@@ -76,25 +51,43 @@ std::string encrypt(const uint8_t input[], size_t input_len,
mac (20 bytes)
ciphertext
*/
- const size_t ciphertext_len = pipe.remaining(0);
-
- std::vector<uint8_t> out_buf(VERSION_CODE_LEN +
- PBKDF_SALT_LEN +
- MAC_OUTPUT_LEN +
- ciphertext_len);
-
+ secure_vector<uint8_t> out_buf(HEADER_LEN + input_len);
for(size_t i = 0; i != VERSION_CODE_LEN; ++i)
out_buf[i] = get_byte(i, CRYPTOBOX_VERSION_CODE);
+ rng.randomize(&out_buf[VERSION_CODE_LEN], PBKDF_SALT_LEN);
+ // space left for MAC here
+ copy_mem(&out_buf[HEADER_LEN], input, input_len);
- copy_mem(&out_buf[VERSION_CODE_LEN], pbkdf_salt.data(), PBKDF_SALT_LEN);
+ // Generate the keys and IV
- BOTAN_ASSERT_EQUAL(
- pipe.read(&out_buf[VERSION_CODE_LEN + PBKDF_SALT_LEN], MAC_OUTPUT_LEN, 1),
- MAC_OUTPUT_LEN, "MAC output");
- BOTAN_ASSERT_EQUAL(
- pipe.read(&out_buf[VERSION_CODE_LEN + PBKDF_SALT_LEN + MAC_OUTPUT_LEN],
- ciphertext_len, 0),
- ciphertext_len, "Ciphertext size");
+ std::unique_ptr<PBKDF> pbkdf(PBKDF::create_or_throw("PBKDF2(HMAC(SHA-512))"));
+
+ OctetString master_key = pbkdf->derive_key(
+ CIPHER_KEY_LEN + MAC_KEY_LEN + CIPHER_IV_LEN,
+ passphrase,
+ &out_buf[VERSION_CODE_LEN],
+ PBKDF_SALT_LEN,
+ PBKDF_ITERATIONS);
+
+ const uint8_t* mk = master_key.begin();
+ const uint8_t* cipher_key = mk;
+ const uint8_t* mac_key = mk + CIPHER_KEY_LEN;
+ const uint8_t* iv = mk + CIPHER_KEY_LEN + MAC_KEY_LEN;
+
+ // Now encrypt and authenticate
+ std::unique_ptr<Cipher_Mode> ctr(get_cipher_mode("Serpent/CTR-BE", ENCRYPTION));
+ ctr->set_key(cipher_key, CIPHER_KEY_LEN);
+ ctr->start(iv, CIPHER_IV_LEN);
+ ctr->finish(out_buf, HEADER_LEN);
+
+ std::unique_ptr<MessageAuthenticationCode> hmac =
+ MessageAuthenticationCode::create_or_throw("HMAC(SHA-512)");
+ hmac->set_key(mac_key, MAC_KEY_LEN);
+ hmac->update(&out_buf[HEADER_LEN], input_len);
+
+ // Can't write directly because of MAC truncation
+ secure_vector<uint8_t> mac = hmac->final();
+ copy_mem(&out_buf[VERSION_CODE_LEN + PBKDF_SALT_LEN], mac.data(), MAC_OUTPUT_LEN);
return PEM_Code::encode(out_buf, "BOTAN CRYPTOBOX MESSAGE");
}
diff --git a/src/lib/pbkdf/pbkdf.cpp b/src/lib/pbkdf/pbkdf.cpp
index 40610998b..d2dfc3d41 100644
--- a/src/lib/pbkdf/pbkdf.cpp
+++ b/src/lib/pbkdf/pbkdf.cpp
@@ -68,6 +68,18 @@ std::unique_ptr<PBKDF> PBKDF::create(const std::string& algo_spec,
return nullptr;
}
+//static
+std::unique_ptr<PBKDF>
+PBKDF::create_or_throw(const std::string& algo,
+ const std::string& provider)
+ {
+ if(auto pbkdf = PBKDF::create(algo, provider))
+ {
+ return pbkdf;
+ }
+ throw Lookup_Error("PBKDF", algo, provider);
+ }
+
std::vector<std::string> PBKDF::providers(const std::string& algo_spec)
{
return probe_providers_of<PBKDF>(algo_spec, { "base", "openssl" });
diff --git a/src/lib/pbkdf/pbkdf.h b/src/lib/pbkdf/pbkdf.h
index a86f4d5c1..7c397da22 100644
--- a/src/lib/pbkdf/pbkdf.h
+++ b/src/lib/pbkdf/pbkdf.h
@@ -33,6 +33,15 @@ class BOTAN_PUBLIC_API(2,0) PBKDF
const std::string& provider = "");
/**
+ * Create an instance based on a name, or throw if the
+ * algo/provider combination cannot be found. If provider is
+ * empty then best available is chosen.
+ */
+ static std::unique_ptr<PBKDF>
+ create_or_throw(const std::string& algo_spec,
+ const std::string& provider = "");
+
+ /**
* @return list of available providers for this algorithm, empty if not available
*/
static std::vector<std::string> providers(const std::string& algo_spec);
diff --git a/src/tests/test_cryptobox.cpp b/src/tests/test_cryptobox.cpp
index a45c2cfef..4e2ba83c2 100644
--- a/src/tests/test_cryptobox.cpp
+++ b/src/tests/test_cryptobox.cpp
@@ -22,33 +22,31 @@ class Cryptobox_Tests final : public Test
public:
std::vector<Test::Result> run() override
{
- std::vector<Test::Result> results;
Test::Result result("cryptobox");
- const std::vector<uint8_t> msg = Botan::hex_decode("AABBCC");
- const std::string password = "secret";
-
- std::string ciphertext = Botan::CryptoBox::encrypt(msg.data(), msg.size(),
- password,
- Test::rng());
-
- try
- {
- std::string plaintext = Botan::CryptoBox::decrypt(ciphertext, password);
-
- const uint8_t* pt_b = reinterpret_cast<const uint8_t*>(plaintext.data());
-
- std::vector<uint8_t> pt_vec(pt_b, pt_b + plaintext.size());
-
- result.test_eq("decrypt", pt_vec, msg);
- }
- catch(std::exception& e)
+ for(size_t i = 0; i <= 128; i += 7)
{
- result.test_failure("cryptobox decrypt", e.what());
+ const std::string password = Test::random_password();
+ const std::vector<uint8_t> input = unlock(Test::rng().random_vec(i));
+
+ const std::string ciphertext =
+ Botan::CryptoBox::encrypt(input.data(), input.size(), password, Test::rng());
+
+ try
+ {
+ const std::string decrypted = Botan::CryptoBox::decrypt(ciphertext, password);
+
+ const uint8_t* pt_b = reinterpret_cast<const uint8_t*>(decrypted.data());
+ std::vector<uint8_t> pt_vec(pt_b, pt_b + decrypted.size());
+ result.test_eq("decrypt", pt_vec, input);
+ }
+ catch(std::exception& e)
+ {
+ result.test_failure("cryptobox decrypt", e.what());
+ }
}
- results.push_back(result);
- return results;
+ return {result};
}
};
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 16:07:04 +0000