aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--src/constructs/cryptobox/cryptobox.h25
-rw-r--r--src/constructs/cryptobox/raw_key.cpp134
-rw-r--r--src/tls/tls_session.cpp105
3 files changed, 163 insertions, 101 deletions
diff --git a/src/constructs/cryptobox/cryptobox.h b/src/constructs/cryptobox/cryptobox.h
index ce1bb9ab0..e70492d37 100644
--- a/src/constructs/cryptobox/cryptobox.h
+++ b/src/constructs/cryptobox/cryptobox.h
@@ -10,6 +10,7 @@
#include <string>
#include <botan/rng.h>
+#include <botan/symkey.h>
namespace Botan {
@@ -29,6 +30,7 @@ BOTAN_DLL std::string encrypt(const byte input[], size_t input_len,
const std::string& passphrase,
RandomNumberGenerator& rng);
+
/**
* Decrypt a message encrypted with CryptoBox::encrypt
* @param input the input data
@@ -46,6 +48,29 @@ BOTAN_DLL std::string decrypt(const byte input[], size_t input_len,
BOTAN_DLL std::string decrypt(const std::string& input,
const std::string& passphrase);
+/**
+* Encrypt a message using a shared key
+* @param input the input data
+* @param input_len the length of input in bytes
+* @param key the key used to encrypt the message
+* @param rng a ref to a random number generator, such as AutoSeeded_RNG
+*/
+BOTAN_DLL std::vector<byte>
+encrypt(const byte input[], size_t input_len,
+ const SymmetricKey& key,
+ RandomNumberGenerator& rng);
+
+/**
+* Encrypt a message using a shared key
+* @param input the input data
+* @param input_len the length of input in bytes
+* @param key the key used to encrypt the message
+* @param rng a ref to a random number generator, such as AutoSeeded_RNG
+*/
+BOTAN_DLL secure_vector<byte>
+decrypt(const byte input[], size_t input_len,
+ const SymmetricKey& key);
+
}
}
diff --git a/src/constructs/cryptobox/raw_key.cpp b/src/constructs/cryptobox/raw_key.cpp
new file mode 100644
index 000000000..9fc912c0c
--- /dev/null
+++ b/src/constructs/cryptobox/raw_key.cpp
@@ -0,0 +1,134 @@
+/*
+* Cryptobox Message Routines
+* (C) 2013 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/cryptobox.h>
+#include <botan/pipe.h>
+#include <botan/lookup.h>
+#include <botan/loadstor.h>
+#include <memory>
+
+namespace Botan {
+
+namespace CryptoBox {
+
+namespace {
+
+const u32bit CRYPTOBOX_MAGIC = 0x571B0E4F;
+const std::string CRYPTOBOX_CIPHER = "AES-256/CBC";
+const std::string CRYPTOBOX_MAC = "HMAC(SHA-256)";
+const std::string CRYPTOBOX_KDF = "KDF2(SHA-256)";
+
+const size_t MAGIC_LENGTH = 4;
+const size_t KEY_KDF_SALT_LENGTH = 10;
+const size_t MAC_KEY_LENGTH = 32;
+const size_t CIPHER_KEY_LENGTH = 32;
+const size_t CIPHER_IV_LENGTH = 16;
+const size_t MAC_OUTPUT_LENGTH = 32;
+
+}
+
+std::vector<byte> encrypt(const byte input[], size_t input_len,
+ const SymmetricKey& master_key,
+ RandomNumberGenerator& rng)
+ {
+ std::unique_ptr<KDF> kdf(get_kdf(CRYPTOBOX_KDF));
+
+ const secure_vector<byte> cipher_key_salt =
+ rng.random_vec(KEY_KDF_SALT_LENGTH);
+
+ const secure_vector<byte> mac_key_salt =
+ rng.random_vec(KEY_KDF_SALT_LENGTH);
+
+ SymmetricKey cipher_key =
+ kdf->derive_key(CIPHER_KEY_LENGTH,
+ master_key.bits_of(),
+ cipher_key_salt);
+
+ SymmetricKey mac_key =
+ kdf->derive_key(MAC_KEY_LENGTH,
+ master_key.bits_of(),
+ mac_key_salt);
+
+ InitializationVector cipher_iv(rng, 16);
+
+ std::unique_ptr<MessageAuthenticationCode> mac(get_mac(CRYPTOBOX_MAC));
+ mac->set_key(mac_key);
+
+ Pipe pipe(get_cipher(CRYPTOBOX_CIPHER, cipher_key, cipher_iv, ENCRYPTION));
+ pipe.process_msg(input, input_len);
+ secure_vector<byte> ctext = pipe.read_all(0);
+
+ std::vector<byte> out(MAGIC_LENGTH);
+ store_be(CRYPTOBOX_MAGIC, &out[0]);
+ out += cipher_key_salt;
+ out += mac_key_salt;
+ out += cipher_iv.bits_of();
+ out += ctext;
+
+ mac->update(out);
+
+ out += mac->final();
+ return out;
+ }
+
+secure_vector<byte> decrypt(const byte input[], size_t input_len,
+ const SymmetricKey& master_key)
+ {
+ const size_t MIN_CTEXT_SIZE = 16; // due to using CBC with padding
+
+ const size_t MIN_POSSIBLE_LENGTH =
+ MAGIC_LENGTH +
+ 2 * KEY_KDF_SALT_LENGTH +
+ CIPHER_IV_LENGTH +
+ MIN_CTEXT_SIZE +
+ MAC_OUTPUT_LENGTH;
+
+ if(input_len < MIN_POSSIBLE_LENGTH)
+ throw Decoding_Error("Encrypted input too short to be valid");
+
+ if(load_be<u32bit>(input, 0) != CRYPTOBOX_MAGIC)
+ throw Decoding_Error("Unknown header value in cryptobox");
+
+ std::unique_ptr<KDF> kdf(get_kdf(CRYPTOBOX_KDF));
+
+ const byte* cipher_key_salt = &input[MAGIC_LENGTH];
+
+ const byte* mac_key_salt = &input[MAGIC_LENGTH + KEY_KDF_SALT_LENGTH];
+
+ SymmetricKey mac_key = kdf->derive_key(MAC_KEY_LENGTH,
+ master_key.bits_of(),
+ mac_key_salt,
+ KEY_KDF_SALT_LENGTH);
+
+ std::unique_ptr<MessageAuthenticationCode> mac(get_mac(CRYPTOBOX_MAC));
+ mac->set_key(mac_key);
+
+ mac->update(&input[0], input_len - MAC_OUTPUT_LENGTH);
+ secure_vector<byte> computed_mac = mac->final();
+
+ if(!same_mem(&input[input_len - MAC_OUTPUT_LENGTH], &computed_mac[0], computed_mac.size()))
+ throw Decoding_Error("MAC verification failed");
+
+ SymmetricKey cipher_key =
+ kdf->derive_key(CIPHER_KEY_LENGTH,
+ master_key.bits_of(),
+ cipher_key_salt, KEY_KDF_SALT_LENGTH);
+
+ InitializationVector cipher_iv(&input[MAGIC_LENGTH+2*KEY_KDF_SALT_LENGTH],
+ CIPHER_IV_LENGTH);
+
+ const size_t CTEXT_OFFSET = MAGIC_LENGTH + 2 * KEY_KDF_SALT_LENGTH + CIPHER_IV_LENGTH;
+
+ Pipe pipe(get_cipher(CRYPTOBOX_CIPHER, cipher_key, cipher_iv, DECRYPTION));
+ pipe.process_msg(&input[CTEXT_OFFSET],
+ input_len - (MAC_OUTPUT_LENGTH + CTEXT_OFFSET));
+ return pipe.read_all();
+ }
+
+}
+
+}
diff --git a/src/tls/tls_session.cpp b/src/tls/tls_session.cpp
index 85cb6d69e..9d869116c 100644
--- a/src/tls/tls_session.cpp
+++ b/src/tls/tls_session.cpp
@@ -10,8 +10,7 @@
#include <botan/ber_dec.h>
#include <botan/asn1_str.h>
#include <botan/pem.h>
-#include <botan/lookup.h>
-#include <botan/loadstor.h>
+#include <botan/cryptobox.h>
#include <memory>
namespace Botan {
@@ -147,64 +146,13 @@ std::chrono::seconds Session::session_age() const
std::chrono::system_clock::now() - m_start_time);
}
-namespace {
-
-const u32bit SESSION_CRYPTO_MAGIC = 0x571B0E4F;
-const std::string SESSION_CRYPTO_CIPHER = "AES-256/CBC";
-const std::string SESSION_CRYPTO_MAC = "HMAC(SHA-256)";
-const std::string SESSION_CRYPTO_KDF = "KDF2(SHA-256)";
-
-const size_t MAGIC_LENGTH = 4;
-const size_t KEY_KDF_SALT_LENGTH = 10;
-const size_t MAC_KEY_LENGTH = 32;
-const size_t CIPHER_KEY_LENGTH = 32;
-const size_t CIPHER_IV_LENGTH = 16;
-const size_t MAC_OUTPUT_LENGTH = 32;
-
-}
-
std::vector<byte>
Session::encrypt(const SymmetricKey& master_key,
RandomNumberGenerator& rng) const
{
- std::unique_ptr<KDF> kdf(get_kdf(SESSION_CRYPTO_KDF));
-
- const secure_vector<byte> cipher_key_salt =
- rng.random_vec(KEY_KDF_SALT_LENGTH);
-
- const secure_vector<byte> mac_key_salt =
- rng.random_vec(KEY_KDF_SALT_LENGTH);
-
- SymmetricKey cipher_key =
- kdf->derive_key(CIPHER_KEY_LENGTH,
- master_key.bits_of(),
- cipher_key_salt);
-
- SymmetricKey mac_key =
- kdf->derive_key(MAC_KEY_LENGTH,
- master_key.bits_of(),
- mac_key_salt);
-
- InitializationVector cipher_iv(rng, 16);
-
- std::unique_ptr<MessageAuthenticationCode> mac(get_mac(SESSION_CRYPTO_MAC));
- mac->set_key(mac_key);
-
- Pipe pipe(get_cipher(SESSION_CRYPTO_CIPHER, cipher_key, cipher_iv, ENCRYPTION));
- pipe.process_msg(this->DER_encode());
- secure_vector<byte> ctext = pipe.read_all(0);
-
- std::vector<byte> out(MAGIC_LENGTH);
- store_be(SESSION_CRYPTO_MAGIC, &out[0]);
- out += cipher_key_salt;
- out += mac_key_salt;
- out += cipher_iv.bits_of();
- out += ctext;
-
- mac->update(out);
+ const auto der = this->DER_encode();
- out += mac->final();
- return out;
+ return CryptoBox::encrypt(&der[0], der.size(), master_key, rng);
}
Session Session::decrypt(const byte buf[], size_t buf_len,
@@ -212,52 +160,7 @@ Session Session::decrypt(const byte buf[], size_t buf_len,
{
try
{
- const size_t MIN_CTEXT_SIZE = 4 * 16; // due to 48 byte master secret
-
- if(buf_len < (MAGIC_LENGTH +
- 2 * KEY_KDF_SALT_LENGTH +
- CIPHER_IV_LENGTH +
- MIN_CTEXT_SIZE +
- MAC_OUTPUT_LENGTH))
- throw Decoding_Error("Encrypted TLS session too short to be valid");
-
- if(load_be<u32bit>(buf, 0) != SESSION_CRYPTO_MAGIC)
- throw Decoding_Error("Unknown header value in encrypted session");
-
- std::unique_ptr<KDF> kdf(get_kdf(SESSION_CRYPTO_KDF));
-
- const byte* cipher_key_salt = &buf[MAGIC_LENGTH];
-
- const byte* mac_key_salt = &buf[MAGIC_LENGTH + KEY_KDF_SALT_LENGTH];
-
- SymmetricKey mac_key =
- kdf->derive_key(MAC_KEY_LENGTH,
- master_key.bits_of(),
- mac_key_salt, KEY_KDF_SALT_LENGTH);
-
- std::unique_ptr<MessageAuthenticationCode> mac(get_mac(SESSION_CRYPTO_MAC));
- mac->set_key(mac_key);
-
- mac->update(&buf[0], buf_len - MAC_OUTPUT_LENGTH);
- secure_vector<byte> computed_mac = mac->final();
-
- if(!same_mem(&buf[buf_len - MAC_OUTPUT_LENGTH], &computed_mac[0], computed_mac.size()))
- throw Decoding_Error("MAC verification failed for encrypted session");
-
- SymmetricKey cipher_key =
- kdf->derive_key(CIPHER_KEY_LENGTH,
- master_key.bits_of(),
- cipher_key_salt, KEY_KDF_SALT_LENGTH);
-
- InitializationVector cipher_iv(&buf[MAGIC_LENGTH+2*KEY_KDF_SALT_LENGTH],
- CIPHER_IV_LENGTH);
-
- const size_t CTEXT_OFFSET = MAGIC_LENGTH + 2 * KEY_KDF_SALT_LENGTH + CIPHER_IV_LENGTH;
-
- Pipe pipe(get_cipher(SESSION_CRYPTO_CIPHER, cipher_key, cipher_iv, DECRYPTION));
- pipe.process_msg(&buf[CTEXT_OFFSET],
- buf_len - (MAC_OUTPUT_LENGTH + CTEXT_OFFSET));
- secure_vector<byte> ber = pipe.read_all();
+ const auto ber = CryptoBox::decrypt(buf, buf_len, master_key);
return Session(&ber[0], ber.size());
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 10:20:42 +0000