Commit 757c4225 authored by Richard van der Hoff's avatar Richard van der Hoff
Browse files

Remove unused 'chain_index' from Ratchet

This was introduced when I was experimenting with support for logging progress
in Olm. That is now relegated to the logging_enabled branch, so this should
probably be removed.

This also fixes the incompatibility of session pickles from the current master
branch with those from olm 0.1.0.
parent 80367293
......@@ -81,16 +81,6 @@ struct Ratchet {
/** The last error that happened encrypting or decrypting a message. */
OlmErrorCode last_error;
/**
* A count of the number of times the root key has been advanced; this is
* maintained purely for diagnostics.
*
* If sender_chain is empty, this will be the index of the current receiver
* chain (odd for Alice, even for Bob); otherwise, the index of the current
* sender chain (even for Alice, odd for Bob).
*/
std::uint32_t chain_index;
/** The root key is used to generate chain keys from the ephemeral keys.
* A new root_key derived each time a new chain is started. */
SharedKey root_key;
......
......@@ -66,7 +66,6 @@ static void create_chain_key(
static void advance_chain_key(
std::uint32_t chain_index,
olm::ChainKey const & chain_key,
olm::ChainKey & new_chain_key
) {
......@@ -80,7 +79,6 @@ static void advance_chain_key(
static void create_message_keys(
std::uint32_t chain_index,
olm::ChainKey const & chain_key,
olm::KdfInfo const & info,
olm::MessageKey & message_key) {
......@@ -111,7 +109,6 @@ static std::size_t verify_mac_and_decrypt(
static std::size_t verify_mac_and_decrypt_for_existing_chain(
olm::Ratchet const & session,
std::uint32_t chain_index,
olm::ChainKey const & chain,
olm::MessageReader const & reader,
std::uint8_t * plaintext, std::size_t max_plaintext_length
......@@ -128,11 +125,11 @@ static std::size_t verify_mac_and_decrypt_for_existing_chain(
olm::ChainKey new_chain = chain;
while (new_chain.index < reader.counter) {
advance_chain_key(chain_index, new_chain, new_chain);
advance_chain_key(new_chain, new_chain);
}
olm::MessageKey message_key;
create_message_keys(chain_index, new_chain, session.kdf_info, message_key);
create_message_keys(new_chain, session.kdf_info, message_key);
std::size_t result = verify_mac_and_decrypt(
session.ratchet_cipher, message_key, reader,
......@@ -164,14 +161,13 @@ static std::size_t verify_mac_and_decrypt_for_new_chain(
}
olm::load_array(new_chain.ratchet_key.public_key, reader.ratchet_key);
std::uint32_t chain_index = session.chain_index + 1;
create_chain_key(
session.root_key, session.sender_chain[0].ratchet_key,
new_chain.ratchet_key, session.kdf_info,
new_root_key, new_chain.chain_key
);
std::size_t result = verify_mac_and_decrypt_for_existing_chain(
session, chain_index, new_chain.chain_key, reader,
session, new_chain.chain_key, reader,
plaintext, max_plaintext_length
);
olm::unset(new_root_key);
......@@ -208,7 +204,6 @@ void olm::Ratchet::initialise_as_bob(
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;
chain_index = 0;
olm::unset(derived_secrets);
}
......@@ -230,7 +225,6 @@ void olm::Ratchet::initialise_as_alice(
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;
chain_index = 0;
olm::unset(derived_secrets);
}
......@@ -369,7 +363,6 @@ std::size_t olm::pickle_length(
length += olm::pickle_length(value.sender_chain);
length += olm::pickle_length(value.receiver_chains);
length += olm::pickle_length(value.skipped_message_keys);
length += olm::pickle_length(value.chain_index);
return length;
}
......@@ -381,7 +374,6 @@ std::uint8_t * olm::pickle(
pos = pickle(pos, value.sender_chain);
pos = pickle(pos, value.receiver_chains);
pos = pickle(pos, value.skipped_message_keys);
pos = pickle(pos, value.chain_index);
return pos;
}
......@@ -394,7 +386,6 @@ std::uint8_t const * olm::unpickle(
pos = unpickle(pos, end, value.sender_chain);
pos = unpickle(pos, end, value.receiver_chains);
pos = unpickle(pos, end, value.skipped_message_keys);
pos = unpickle(pos, end, value.chain_index);
return pos;
}
......@@ -447,12 +438,11 @@ std::size_t olm::Ratchet::encrypt(
kdf_info,
root_key, sender_chain[0].chain_key
);
chain_index++;
}
MessageKey keys;
create_message_keys(chain_index, sender_chain[0].chain_key, kdf_info, keys);
advance_chain_key(chain_index, sender_chain[0].chain_key, sender_chain[0].chain_key);
create_message_keys(sender_chain[0].chain_key, kdf_info, keys);
advance_chain_key(sender_chain[0].chain_key, sender_chain[0].chain_key);
std::size_t ciphertext_length = ratchet_cipher->ops->encrypt_ciphertext_length(
ratchet_cipher,
......@@ -538,12 +528,6 @@ std::size_t olm::Ratchet::decrypt(
}
ReceiverChain * chain = nullptr;
auto receiver_chain_index = chain_index;
if (!sender_chain.empty()) {
// we've already advanced to the next (sender) chain; decrement to
// get back to the receiver chains
receiver_chain_index --;
}
for (olm::ReceiverChain & receiver_chain : receiver_chains) {
if (0 == std::memcmp(
......@@ -553,7 +537,6 @@ std::size_t olm::Ratchet::decrypt(
chain = &receiver_chain;
break;
}
receiver_chain_index -= 2;
}
std::size_t result = std::size_t(-1);
......@@ -590,7 +573,7 @@ std::size_t olm::Ratchet::decrypt(
}
} else {
result = verify_mac_and_decrypt_for_existing_chain(
*this, receiver_chain_index, chain->chain_key,
*this, chain->chain_key,
reader, plaintext, max_plaintext_length
);
}
......@@ -618,17 +601,16 @@ std::size_t olm::Ratchet::decrypt(
olm::unset(sender_chain[0]);
sender_chain.erase(sender_chain.begin());
receiver_chain_index = ++chain_index;
}
while (chain->chain_key.index < reader.counter) {
olm::SkippedMessageKey & key = *skipped_message_keys.insert();
create_message_keys(receiver_chain_index, chain->chain_key, kdf_info, key.message_key);
create_message_keys(chain->chain_key, kdf_info, key.message_key);
key.ratchet_key = chain->ratchet_key;
advance_chain_key(receiver_chain_index, chain->chain_key, chain->chain_key);
advance_chain_key(chain->chain_key, chain->chain_key);
}
advance_chain_key(receiver_chain_index, chain->chain_key, chain->chain_key);
advance_chain_key(chain->chain_key, chain->chain_key);
return result;
}
#include "olm/olm.h"
#include "unittest.hh"
const char * test_cases[] = {
"41776f",
"7fff6f0101346d671201",
"ee776f41496f674177804177778041776f6716670a677d6f670a67c2677d",
"e9e9c9c1e9e9c9e9c9c1e9e9c9c1",
struct test_case {
const char *msghex;
const char *expected_error;
};
const test_case test_cases[] = {
{ "41776f", "BAD_MESSAGE_FORMAT" },
{ "7fff6f0101346d671201", "BAD_MESSAGE_FORMAT" },
{ "ee776f41496f674177804177778041776f6716670a677d6f670a67c2677d", "BAD_MESSAGE_FORMAT" },
{ "e9e9c9c1e9e9c9e9c9c1e9e9c9c1", "BAD_MESSAGE_FORMAT" },
};
......@@ -31,29 +36,39 @@ void decode_hex(
}
}
void decrypt_case(int message_type, const char * test_case) {
void decrypt_case(int message_type, const test_case * test_case) {
std::uint8_t session_memory[olm_session_size()];
::OlmSession * session = ::olm_session(session_memory);
std::uint8_t pickled[strlen(session_data)];
::memcpy(pickled, session_data, sizeof(pickled));
::olm_unpickle_session(session, "", 0, pickled, sizeof(pickled));
assert_not_equals(
::olm_error(),
::olm_unpickle_session(session, "", 0, pickled, sizeof(pickled))
);
std::size_t message_length = strlen(test_case) / 2;
std::size_t message_length = strlen(test_case->msghex) / 2;
std::uint8_t * message = (std::uint8_t *) ::malloc(message_length);
decode_hex(test_case, message, message_length);
decode_hex(test_case->msghex, message, message_length);
size_t max_length = olm_decrypt_max_plaintext_length(
session, message_type, message, message_length
);
if (max_length == std::size_t(-1)) {
if (test_case->expected_error) {
assert_equals(::olm_error(), max_length);
assert_equals(
std::string(test_case->expected_error),
std::string(::olm_session_last_error(session))
);
free(message);
return;
}
assert_not_equals(::olm_error(), max_length);
uint8_t plaintext[max_length];
decode_hex(test_case, message, message_length);
decode_hex(test_case->msghex, message, message_length);
olm_decrypt(
session, message_type,
message, message_length,
......@@ -67,8 +82,8 @@ int main() {
{
TestCase my_test("Olm decrypt test");
for (unsigned int i = 0; i < sizeof(test_cases)/ sizeof(const char *); ++i) {
decrypt_case(0, test_cases[i]);
for (unsigned int i = 0; i < sizeof(test_cases)/ sizeof(test_cases[0]); ++i) {
decrypt_case(0, &test_cases[i]);
}
}
......
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