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-rw-r--r--src/ratchet.cpp73
1 files changed, 36 insertions, 37 deletions
diff --git a/src/ratchet.cpp b/src/ratchet.cpp
index b9108db..5ef1e56 100644
--- a/src/ratchet.cpp
+++ b/src/ratchet.cpp
@@ -23,13 +23,12 @@
namespace {
-std::uint8_t PROTOCOL_VERSION = 3;
-std::size_t KEY_LENGTH = olm::Curve25519PublicKey::LENGTH;
-std::uint8_t MESSAGE_KEY_SEED[1] = {0x01};
-std::uint8_t CHAIN_KEY_SEED[1] = {0x02};
-std::size_t MAX_MESSAGE_GAP = 2000;
+static const std::uint8_t PROTOCOL_VERSION = 3;
+static const std::uint8_t MESSAGE_KEY_SEED[1] = {0x01};
+static const std::uint8_t CHAIN_KEY_SEED[1] = {0x02};
+static const std::size_t MAX_MESSAGE_GAP = 2000;
-void create_chain_key(
+static void create_chain_key(
olm::SharedKey const & root_key,
olm::Curve25519KeyPair const & our_key,
olm::Curve25519PublicKey const & their_key,
@@ -39,22 +38,23 @@ void create_chain_key(
) {
olm::SharedKey secret;
olm::curve25519_shared_secret(our_key, their_key, secret);
- std::uint8_t derived_secrets[64];
+ std::uint8_t derived_secrets[2 * olm::KEY_LENGTH];
olm::hkdf_sha256(
secret, sizeof(secret),
root_key, sizeof(root_key),
info.ratchet_info, info.ratchet_info_length,
derived_secrets, sizeof(derived_secrets)
);
- std::memcpy(new_root_key, derived_secrets, 32);
- std::memcpy(new_chain_key.key, derived_secrets + 32, 32);
+ std::uint8_t const * pos = derived_secrets;
+ pos = olm::load_array(new_root_key, pos);
+ pos = olm::load_array(new_chain_key.key, pos);
new_chain_key.index = 0;
olm::unset(derived_secrets);
olm::unset(secret);
}
-void advance_chain_key(
+static void advance_chain_key(
olm::ChainKey const & chain_key,
olm::ChainKey & new_chain_key
) {
@@ -67,7 +67,7 @@ void advance_chain_key(
}
-void create_message_keys(
+static void create_message_keys(
olm::ChainKey const & chain_key,
olm::KdfInfo const & info,
olm::MessageKey & message_key
@@ -81,7 +81,7 @@ void create_message_keys(
}
-std::size_t verify_mac_and_decrypt(
+static std::size_t verify_mac_and_decrypt(
olm::Cipher const & cipher,
olm::MessageKey const & message_key,
olm::MessageReader const & reader,
@@ -96,7 +96,7 @@ std::size_t verify_mac_and_decrypt(
}
-std::size_t verify_mac_and_decrypt_for_existing_chain(
+static std::size_t verify_mac_and_decrypt_for_existing_chain(
olm::Ratchet const & session,
olm::ChainKey const & chain,
olm::MessageReader const & reader,
@@ -130,7 +130,7 @@ std::size_t verify_mac_and_decrypt_for_existing_chain(
}
-std::size_t verify_mac_and_decrypt_for_new_chain(
+static std::size_t verify_mac_and_decrypt_for_new_chain(
olm::Ratchet const & session,
olm::MessageReader const & reader,
std::uint8_t * plaintext, std::size_t max_plaintext_length
@@ -148,9 +148,7 @@ std::size_t verify_mac_and_decrypt_for_new_chain(
if (reader.counter > MAX_MESSAGE_GAP) {
return std::size_t(-1);
}
- std::memcpy(
- new_chain.ratchet_key.public_key, reader.ratchet_key, KEY_LENGTH
- );
+ olm::load_array(new_chain.ratchet_key.public_key, reader.ratchet_key);
create_chain_key(
session.root_key, session.sender_chain[0].ratchet_key,
@@ -183,7 +181,7 @@ void olm::Ratchet::initialise_as_bob(
std::uint8_t const * shared_secret, std::size_t shared_secret_length,
olm::Curve25519PublicKey const & their_ratchet_key
) {
- std::uint8_t derived_secrets[64];
+ std::uint8_t derived_secrets[2 * olm::KEY_LENGTH];
olm::hkdf_sha256(
shared_secret, shared_secret_length,
nullptr, 0,
@@ -192,8 +190,9 @@ void olm::Ratchet::initialise_as_bob(
);
receiver_chains.insert();
receiver_chains[0].chain_key.index = 0;
- std::memcpy(root_key, derived_secrets, 32);
- std::memcpy(receiver_chains[0].chain_key.key, derived_secrets + 32, 32);
+ std::uint8_t const * pos = derived_secrets;
+ pos = olm::load_array(root_key, pos);
+ pos = olm::load_array(receiver_chains[0].chain_key.key, pos);
receiver_chains[0].ratchet_key = their_ratchet_key;
olm::unset(derived_secrets);
}
@@ -203,7 +202,7 @@ void olm::Ratchet::initialise_as_alice(
std::uint8_t const * shared_secret, std::size_t shared_secret_length,
olm::Curve25519KeyPair const & our_ratchet_key
) {
- std::uint8_t derived_secrets[64];
+ std::uint8_t derived_secrets[2 * olm::KEY_LENGTH];
olm::hkdf_sha256(
shared_secret, shared_secret_length,
nullptr, 0,
@@ -212,8 +211,9 @@ void olm::Ratchet::initialise_as_alice(
);
sender_chain.insert();
sender_chain[0].chain_key.index = 0;
- std::memcpy(root_key, derived_secrets, 32);
- std::memcpy(sender_chain[0].chain_key.key, derived_secrets + 32, 32);
+ std::uint8_t const * pos = derived_secrets;
+ pos = olm::load_array(root_key, pos);
+ pos = olm::load_array(sender_chain[0].chain_key.key, pos);
sender_chain[0].ratchet_key = our_ratchet_key;
olm::unset(derived_secrets);
}
@@ -224,7 +224,7 @@ namespace olm {
static std::size_t pickle_length(
const olm::SharedKey & value
) {
- return KEY_LENGTH;
+ return olm::KEY_LENGTH;
}
@@ -232,7 +232,7 @@ static std::uint8_t * pickle(
std::uint8_t * pos,
const olm::SharedKey & value
) {
- return olm::pickle_bytes(pos, value, KEY_LENGTH);
+ return olm::pickle_bytes(pos, value, olm::KEY_LENGTH);
}
@@ -240,7 +240,7 @@ static std::uint8_t const * unpickle(
std::uint8_t const * pos, std::uint8_t const * end,
olm::SharedKey & value
) {
- return olm::unpickle_bytes(pos, end, value, KEY_LENGTH);
+ return olm::unpickle_bytes(pos, end, value, olm::KEY_LENGTH);
}
@@ -349,7 +349,7 @@ std::size_t olm::pickle_length(
olm::Ratchet const & value
) {
std::size_t length = 0;
- length += KEY_LENGTH;
+ length += olm::KEY_LENGTH;
length += olm::pickle_length(value.sender_chain);
length += olm::pickle_length(value.receiver_chains);
length += olm::pickle_length(value.skipped_message_keys);
@@ -391,13 +391,13 @@ std::size_t olm::Ratchet::encrypt_output_length(
plaintext_length
);
return olm::encode_message_length(
- counter, KEY_LENGTH, padded, ratchet_cipher.mac_length()
+ counter, olm::KEY_LENGTH, padded, ratchet_cipher.mac_length()
);
}
std::size_t olm::Ratchet::encrypt_random_length() {
- return sender_chain.empty() ? KEY_LENGTH : 0;
+ return sender_chain.empty() ? olm::KEY_LENGTH : 0;
}
@@ -442,10 +442,11 @@ std::size_t olm::Ratchet::encrypt(
olm::MessageWriter writer;
olm::encode_message(
- writer, PROTOCOL_VERSION, counter, KEY_LENGTH, ciphertext_length, output
+ writer, PROTOCOL_VERSION, counter, olm::KEY_LENGTH, ciphertext_length,
+ output
);
- std::memcpy(writer.ratchet_key, ratchet_key.public_key, KEY_LENGTH);
+ olm::store_array(writer.ratchet_key, ratchet_key.public_key);
ratchet_cipher.encrypt(
keys.key, sizeof(keys.key),
@@ -504,7 +505,7 @@ std::size_t olm::Ratchet::decrypt(
return std::size_t(-1);
}
- if (reader.ratchet_key_length != KEY_LENGTH) {
+ if (reader.ratchet_key_length != olm::KEY_LENGTH) {
last_error = olm::ErrorCode::BAD_MESSAGE_FORMAT;
return std::size_t(-1);
}
@@ -513,7 +514,7 @@ std::size_t olm::Ratchet::decrypt(
for (olm::ReceiverChain & receiver_chain : receiver_chains) {
if (0 == std::memcmp(
receiver_chain.ratchet_key.public_key, reader.ratchet_key,
- KEY_LENGTH
+ olm::KEY_LENGTH
)) {
chain = &receiver_chain;
break;
@@ -533,7 +534,7 @@ std::size_t olm::Ratchet::decrypt(
if (reader.counter == skipped.message_key.index
&& 0 == std::memcmp(
skipped.ratchet_key.public_key, reader.ratchet_key,
- KEY_LENGTH
+ olm::KEY_LENGTH
)
) {
/* Found the key for this message. Check the MAC. */
@@ -569,9 +570,7 @@ std::size_t olm::Ratchet::decrypt(
* We can discard our previous empheral ratchet key.
* We will generate a new key when we send the next message. */
chain = receiver_chains.insert();
- std::memcpy(
- chain->ratchet_key.public_key, reader.ratchet_key, KEY_LENGTH
- );
+ olm::load_array(chain->ratchet_key.public_key, reader.ratchet_key);
create_chain_key(
root_key, sender_chain[0].ratchet_key, chain->ratchet_key,
kdf_info, root_key, chain->chain_key
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-08 00:09:10 +0000