Move utils for pickling into a separate file

include/axolotl/account.hh

@@ -41,24 +41,26 @@ struct Account {
     LocalKey const * lookup_key(
         std::uint32_t id
     );
-
-    /** The number of bytes needed to persist this account. */
-    std::size_t pickle_length();
-
-    /** Persists an account as a sequence of bytes
-     * Returns the number of output bytes used. */
-    std::size_t pickle(
-        std::uint8_t * output, std::size_t output_length
-    );
-
-    /** Loads an account from a sequence of bytes.
-     * Returns 0 on success, or std::size_t(-1) on failure. */
-    std::size_t unpickle(
-        std::uint8_t * input, std::size_t input_length
-    );
 };
 
 
+std::size_t pickle_length(
+    Account const & value
+);
+
+
+std::uint8_t * pickle(
+    std::uint8_t * pos,
+    Account const & value
+);
+
+
+std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    Account & value
+);
+
+
 } // namespace axolotl
 
 #endif /* AXOLOTL_ACCOUNT_HH_ */

include/axolotl/pickle.hh

@@ -0,0 +1,164 @@
+#ifndef AXOLOTL_PICKLE_HH_
+#define AXOLOTL_PICKLE_HH_
+
+#include "axolotl/list.hh"
+#include "axolotl/crypto.hh"
+
+#include <cstring>
+#include <cstdint>
+
+namespace axolotl {
+
+static std::size_t pickle_length(
+    const std::uint32_t & value
+) {
+    return 4;
+}
+
+
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    std::uint32_t value
+) {
+    pos += 4;
+    for (unsigned i = 4; i--;) { *(--pos) = value; value >>= 8; }
+    return pos + 4;
+}
+
+
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    std::uint32_t & value
+) {
+    value = 0;
+    if (end - pos < 4) return end;
+    for (unsigned i = 4; i--;) { value <<= 8; value |= *(pos++); }
+    return pos;
+}
+
+static std::size_t pickle_length(
+    const bool & value
+) {
+    return 1;
+}
+
+
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    bool value
+) {
+    *(pos++) = value ? 1 : 0;
+    return pos;
+}
+
+
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    bool & value
+) {
+    if (pos == end) return end;
+    value = *(pos++);
+    return pos;
+}
+
+
+
+template<typename T, std::size_t max_size>
+std::size_t pickle_length(
+    axolotl::List<T, max_size> const & list
+) {
+    std::size_t length = pickle_length(std::uint32_t(list.size()));
+    for (auto const & value : list) {
+        length += pickle_length(value);
+    }
+    return length;
+}
+
+
+template<typename T, std::size_t max_size>
+std::uint8_t * pickle(
+    std::uint8_t * pos,
+    axolotl::List<T, max_size> const & list
+) {
+    pos = pickle(pos, std::uint32_t(list.size()));
+    for (auto const & value : list) {
+        pos = pickle(pos, value);
+    }
+    return pos;
+}
+
+
+template<typename T, std::size_t max_size>
+std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::List<T, max_size> & list
+) {
+    std::uint32_t size;
+    pos = unpickle(pos, end, size);
+    while (size--) {
+        T * value = list.insert(list.end());
+        pos = unpickle(pos, end, *value);
+    }
+    return pos;
+}
+
+
+static std::uint8_t * pickle_bytes(
+    std::uint8_t * pos,
+    std::uint8_t const * bytes, std::size_t bytes_length
+) {
+    std::memcpy(pos, bytes, bytes_length);
+    return pos + bytes_length;
+}
+
+
+static std::uint8_t const * unpickle_bytes(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    std::uint8_t * bytes, std::size_t bytes_length
+) {
+    if (end - pos < bytes_length) return end;
+    std::memcpy(bytes, pos, bytes_length);
+    return pos + bytes_length;
+}
+
+
+std::size_t pickle_length(
+    const Curve25519PublicKey & value
+);
+
+
+std::uint8_t * pickle(
+    std::uint8_t * pos,
+    const Curve25519PublicKey & value
+);
+
+
+std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    Curve25519PublicKey & value
+);
+
+
+std::size_t pickle_length(
+    const Curve25519KeyPair & value
+);
+
+
+std::uint8_t * pickle(
+    std::uint8_t * pos,
+    const Curve25519KeyPair & value
+);
+
+
+std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    Curve25519KeyPair & value
+);
+
+
+} // namespace axolotl
+
+
+
+
+#endif /* AXOLOTL_PICKLE_HH */

include/axolotl/ratchet.hh

@@ -114,21 +114,6 @@ struct Ratchet {
         Curve25519KeyPair const & our_ratchet_key
     );
 
-    /** The number of bytes needed to persist the current session. */
-    std::size_t pickle_length();
-
-    /** Persists a session as a sequence of bytes
-     * Returns the number of output bytes used. */
-    std::size_t pickle(
-        std::uint8_t * output, std::size_t output_length
-    );
-
-    /** Loads a session from a sequence of bytes.
-     * Returns 0 on success, or std::size_t(-1) on failure. */
-    std::size_t unpickle(
-        std::uint8_t * input, std::size_t input_length
-    );
-
     /** The number of bytes of output the encrypt method will write for
      * a given message length. */
     std::size_t encrypt_output_length(
@@ -172,4 +157,21 @@ struct Ratchet {
 };
 
 
+std::size_t pickle_length(
+    Ratchet const & value
+);
+
+
+std::uint8_t * pickle(
+    std::uint8_t * pos,
+    Ratchet const & value
+);
+
+
+std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    Ratchet & value
+);
+
+
 } // namespace axolotl

include/axolotl/session.hh

@@ -78,6 +78,23 @@ struct Session {
 };
 
 
+std::size_t pickle_length(
+    Session const & value
+);
+
+
+std::uint8_t * pickle(
+    std::uint8_t * pos,
+    Session const & value
+);
+
+
+std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    Session & value
+);
+
+
 } // namespace axolotl
 
 #endif /* AXOLOTL_SESSION_HH_ */

src/account.cpp

@@ -0,0 +1,105 @@
+#include "axolotl/account.hh"
+#include "axolotl/pickle.hh"
+
+
+
+axolotl::LocalKey const * axolotl::Account::lookup_key(
+    std::uint32_t id
+) {
+    for (axolotl::LocalKey const & key : one_time_keys) {
+        if (key.id == id) return &key;
+    }
+    return 0;
+}
+
+namespace axolotl {
+
+
+static std::size_t pickle_length(
+    axolotl::LocalKey const & value
+) {
+    return axolotl::pickle_length(value.id) + axolotl::pickle_length(value.key);
+}
+
+
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    axolotl::LocalKey const & value
+) {
+    pos = axolotl::pickle(pos, value.id);
+    pos = axolotl::pickle(pos, value.key);
+    return pos;
+}
+
+
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::LocalKey & value
+) {
+    pos = axolotl::unpickle(pos, end, value.id);
+    pos = axolotl::unpickle(pos, end, value.key);
+    return pos;
+}
+
+
+static std::size_t pickle_length(
+    axolotl::SignedKey const & value
+) {
+    return axolotl::pickle_length((axolotl::LocalKey const &) value) + 64;
+}
+
+
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    axolotl::SignedKey const & value
+) {
+    pos = axolotl::pickle(pos, (axolotl::LocalKey const &) value);
+    pos = axolotl::pickle_bytes(pos, value.signature, 64);
+    return pos;
+}
+
+
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::SignedKey & value
+) {
+    pos = axolotl::unpickle(pos, end, (axolotl::LocalKey &) value);
+    pos = axolotl::unpickle_bytes(pos, end, value.signature, 64);
+    return pos;
+}
+
+
+} // namespace axolotl
+
+
+std::size_t pickle_length(
+    axolotl::Account const & value
+) {
+    std::size_t length = 0;
+    length += axolotl::pickle_length(value.identity_key);
+    length += axolotl::pickle_length(value.last_resort_one_time_key);
+    length += axolotl::pickle_length(value.one_time_keys);
+    return length;
+}
+
+
+std::uint8_t * pickle(
+    std::uint8_t * pos,
+    axolotl::Account const & value
+) {
+    pos = axolotl::pickle(pos, value.identity_key);
+    pos = axolotl::pickle(pos, value.last_resort_one_time_key);
+    pos = axolotl::pickle(pos, value.one_time_keys);
+    return pos;
+}
+
+
+std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::Account & value
+) {
+    pos = axolotl::unpickle(pos, end, value.identity_key);
+    pos = axolotl::unpickle(pos, end, value.last_resort_one_time_key);
+    pos = axolotl::unpickle(pos, end, value.one_time_keys);
+    return pos;
+}

src/pickle.cpp

@@ -0,0 +1,66 @@
+#include "axolotl/pickle.hh"
+
+
+std::size_t axolotl::pickle_length(
+    const axolotl::Curve25519PublicKey & value
+) {
+    return sizeof(value.public_key);
+}
+
+
+std::uint8_t * axolotl::pickle(
+    std::uint8_t * pos,
+    const axolotl::Curve25519PublicKey & value
+) {
+    pos = axolotl::pickle_bytes(
+        pos, value.public_key, sizeof(value.public_key)
+    );
+    return pos;
+}
+
+
+std::uint8_t const * axolotl::unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::Curve25519PublicKey & value
+) {
+    pos = axolotl::unpickle_bytes(
+        pos, end, value.public_key, sizeof(value.public_key)
+    );
+    return pos;
+
+}
+
+
+std::size_t axolotl::pickle_length(
+    const axolotl::Curve25519KeyPair & value
+) {
+    return sizeof(value.public_key) + sizeof(value.private_key);
+}
+
+
+std::uint8_t * axolotl::pickle(
+    std::uint8_t * pos,
+    const axolotl::Curve25519KeyPair & value
+) {
+    pos = axolotl::pickle_bytes(
+        pos, value.public_key, sizeof(value.public_key)
+    );
+    pos = axolotl::pickle_bytes(
+        pos, value.private_key, sizeof(value.private_key)
+    );
+    return pos;
+}
+
+
+std::uint8_t const * axolotl::unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::Curve25519KeyPair & value
+) {
+    pos = axolotl::unpickle_bytes(
+        pos, end, value.public_key, sizeof(value.public_key)
+    );
+    pos = axolotl::unpickle_bytes(
+        pos, end, value.private_key, sizeof(value.private_key)
+    );
+    return pos;
+}

src/ratchet.cpp

@@ -16,6 +16,8 @@
 #include "axolotl/message.hh"
 #include "axolotl/memory.hh"
 #include "axolotl/cipher.hh"
+#include "axolotl/pickle.hh"
+
 
 #include <cstring>
 
@@ -214,137 +216,165 @@ void axolotl::Ratchet::initialise_as_alice(
     axolotl::unset(derived_secrets);
 }
 
+namespace axolotl {
 
-std::size_t axolotl::Ratchet::pickle_length() {
-    std::size_t counter_length = 4;
-    std::size_t send_chain_length = counter_length + 64 + 32;
-    std::size_t recv_chain_length = counter_length + 32 + 32;
-    std::size_t skip_key_length = counter_length + 32 + 32;
-    std::size_t pickle_length = 3 * counter_length + 32;
-    pickle_length += sender_chain.size() * send_chain_length;
-    pickle_length += receiver_chains.size() * recv_chain_length;
-    pickle_length += skipped_message_keys.size() * skip_key_length;
-    return pickle_length;
+
+static std::size_t pickle_length(
+    const axolotl::SharedKey & value
+) {
+    return KEY_LENGTH;
 }
 
-namespace {
 
-std::uint8_t * pickle_counter(
-    std::uint8_t * output, std::uint32_t value
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    const axolotl::SharedKey & value
 ) {
-    unsigned i = 4;
-    output += 4;
-    while (i--) { *(--output) = value; value >>= 8; }
-    return output + 4;
+    return axolotl::pickle_bytes(pos, value, KEY_LENGTH);
 }
 
-std::uint8_t * unpickle_counter(
-    std::uint8_t *input, std::uint32_t &value
+
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::SharedKey & value
 ) {
-    unsigned i = 4;
-    value = 0;
-    while (i--) { value <<= 8; value |= *(input++); }
-    return input;
+    return axolotl::unpickle_bytes(pos, end, value, KEY_LENGTH);
 }
 
-std::uint8_t * pickle_bytes(
-    std::uint8_t * output, std::size_t count, std::uint8_t const * bytes
+
+static std::size_t pickle_length(
+    const axolotl::SenderChain & value
 ) {
-    std::memcpy(output, bytes, count);
-    return output + count;
+    std::size_t length = 0;
+    length += axolotl::pickle_length(value.ratchet_key);
+    length += axolotl::pickle_length(value.chain_key.key);
+    length += axolotl::pickle_length(value.chain_key.index);
+    return length;
 }
 
-std::uint8_t * unpickle_bytes(
-    std::uint8_t * input, std::size_t count, std::uint8_t * bytes
+
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    const axolotl::SenderChain & value
 ) {
-    std::memcpy(bytes, input, count);
-    return input + count;
+    pos = axolotl::pickle(pos, value.ratchet_key);
+    pos = axolotl::pickle(pos, value.chain_key.key);
+    pos = axolotl::pickle(pos, value.chain_key.index);
+    return pos;
 }
 
-} // namespace
 
-
-std::size_t axolotl::Ratchet::pickle(
-    std::uint8_t * output, std::size_t output_length
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::SenderChain & value
 ) {
-    std::uint8_t * pos = output;
-    if (output_length < pickle_length()) {
-        last_error = axolotl::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
-        return std::size_t(-1);
-    }
-
-    pos = pickle_counter(pos, sender_chain.size());
-    pos = pickle_counter(pos, receiver_chains.size());
-    pos = pickle_counter(pos, skipped_message_keys.size());
-    pos = pickle_bytes(pos, 32, root_key);
-    for (const axolotl::SenderChain &chain : sender_chain) {
-        pos = pickle_counter(pos, chain.chain_key.index);
-        pos = pickle_bytes(pos, 32, chain.chain_key.key);
-        pos = pickle_bytes(pos, 32, chain.ratchet_key.public_key);
-        pos = pickle_bytes(pos, 32, chain.ratchet_key.private_key);
-    }
-    for (const axolotl::ReceiverChain &chain : receiver_chains) {
-        pos = pickle_counter(pos, chain.chain_key.index);
-        pos = pickle_bytes(pos, 32, chain.chain_key.key);
-        pos = pickle_bytes(pos, 32, chain.ratchet_key.public_key);
-    }
-    for (const axolotl::SkippedMessageKey &key : skipped_message_keys) {
-        pos = pickle_counter(pos, key.message_key.index);
-        pos = pickle_bytes(pos, 32, key.message_key.key);
-        pos = pickle_bytes(pos, 32, key.ratchet_key.public_key);
-    }
-    return pos - output;
+    pos = axolotl::unpickle(pos, end, value.ratchet_key);
+    pos = axolotl::unpickle(pos, end, value.chain_key.key);
+    pos = axolotl::unpickle(pos, end, value.chain_key.index);
+    return pos;
 }
 
-std::size_t axolotl::Ratchet::unpickle(
-    std::uint8_t * input, std::size_t input_length
+static std::size_t pickle_length(
+    const axolotl::ReceiverChain & value
 ) {
+    std::size_t length = 0;
+    length += axolotl::pickle_length(value.ratchet_key);
+    length += axolotl::pickle_length(value.chain_key.key);
+    length += axolotl::pickle_length(value.chain_key.index);
+    return length;
+}
 
-    std::uint8_t * pos = input;
-    std::uint8_t * end = input + input_length;
-    std::uint32_t send_chain_num, recv_chain_num, skipped_num;
 
-    if (end - pos < 4 * 3 + 32) {} // input too small.
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    const axolotl::ReceiverChain & value
+) {
+    pos = axolotl::pickle(pos, value.ratchet_key);
+    pos = axolotl::pickle(pos, value.chain_key.key);
+    pos = axolotl::pickle(pos, value.chain_key.index);
+    return pos;
+}
 
-    pos = unpickle_counter(pos, send_chain_num);
-    pos = unpickle_counter(pos, recv_chain_num);
-    pos = unpickle_counter(pos, skipped_num);
-    pos = unpickle_bytes(pos, 32, root_key);
 
-    if (end - pos < send_chain_num * (32 * 3 + 4)) {} // input too small.
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::ReceiverChain & value
+) {
+    pos = axolotl::unpickle(pos, end, value.ratchet_key);
+    pos = axolotl::unpickle(pos, end, value.chain_key.key);
+    pos = axolotl::unpickle(pos, end, value.chain_key.index);
+    return pos;
+}
 
-    while (send_chain_num--) {
-        axolotl::SenderChain & chain = *sender_chain.insert(
-            sender_chain.end()
-        );
-        pos = unpickle_counter(pos, chain.chain_key.index);
-        pos = unpickle_bytes(pos, 32, chain.chain_key.key);
-        pos = unpickle_bytes(pos, 32, chain.ratchet_key.public_key);
-        pos = unpickle_bytes(pos, 32, chain.ratchet_key.private_key);
-    }
 
-    if (end - pos < recv_chain_num * (32 * 2 + 4)) {} // input too small.
+static std::size_t pickle_length(
+    const axolotl::SkippedMessageKey & value
+) {
+    std::size_t length = 0;
+    length += axolotl::pickle_length(value.ratchet_key);
+    length += axolotl::pickle_length(value.message_key.key);
+    length += axolotl::pickle_length(value.message_key.index);
+    return length;
+}
 
-    while (recv_chain_num--) {
-        axolotl::ReceiverChain & chain = *receiver_chains.insert(
-            receiver_chains.end()
-        );
-        pos = unpickle_counter(pos, chain.chain_key.index);
-        pos = unpickle_bytes(pos, 32, chain.chain_key.key);
-        pos = unpickle_bytes(pos, 32, chain.ratchet_key.public_key);
-    }
 
-    if (end - pos < skipped_num * (32 * 3 + 16 + 4)) {} // input too small.
+static std::uint8_t * pickle(
+    std::uint8_t * pos,
+    const axolotl::SkippedMessageKey & value
+) {
+    pos = axolotl::pickle(pos, value.ratchet_key);
+    pos = axolotl::pickle(pos, value.message_key.key);
+    pos = axolotl::pickle(pos, value.message_key.index);
+    return pos;
+}
 
-    while (skipped_num--) {
-        axolotl::SkippedMessageKey &key = *skipped_message_keys.insert(
-            skipped_message_keys.end()
-        );
-        pos = unpickle_counter(pos, key.message_key.index);
-        pos = unpickle_bytes(pos, 32, key.message_key.key);
-        pos = unpickle_bytes(pos, 32, key.ratchet_key.public_key);
-    }
-    return pos - input;
+
+static std::uint8_t const * unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::SkippedMessageKey & value
+) {
+    pos = axolotl::unpickle(pos, end, value.ratchet_key);
+    pos = axolotl::unpickle(pos, end, value.message_key.key);
+    pos = axolotl::unpickle(pos, end, value.message_key.index);
+    return pos;
+}
+
+
+} // namespace axolotl
+
+
+std::size_t axolotl::pickle_length(
+    axolotl::Ratchet const & value
+) {
+    std::size_t length = 0;
+    length += KEY_LENGTH;
+    length += axolotl::pickle_length(value.sender_chain);
+    length += axolotl::pickle_length(value.receiver_chains);
+    length += axolotl::pickle_length(value.skipped_message_keys);
+    return length;
+}
+
+std::uint8_t * axolotl::pickle(
+    std::uint8_t * pos,
+    axolotl::Ratchet const & value
+) {
+    pos = pickle(pos, value.root_key);
+    pos = pickle(pos, value.sender_chain);
+    pos = pickle(pos, value.receiver_chains);
+    pos = pickle(pos, value.skipped_message_keys);
+    return pos;
+}
+
+
+std::uint8_t const * axolotl::unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    axolotl::Ratchet & value
+) {
+    pos = unpickle(pos, end, value.root_key);
+    pos = unpickle(pos, end, value.sender_chain);
+    pos = unpickle(pos, end, value.receiver_chains);
+    pos = unpickle(pos, end, value.skipped_message_keys);
+    return pos;
 }
 
 

src/session.cpp

@@ -4,6 +4,7 @@
 #include "axolotl/account.hh"
 #include "axolotl/memory.hh"
 #include "axolotl/message.hh"
+#include "axolotl/pickle.hh"
 
 #include <cstring>
 
@@ -334,3 +335,46 @@ std::size_t axolotl::Session::decrypt(
     }
     return result;
 }
+
+
+std::size_t axolotl::pickle_length(
+    Session const & value
+) {
+    std::size_t length = 0;
+    length += axolotl::pickle_length(value.received_message);
+    length += axolotl::pickle_length(value.alice_identity_key.id);
+    length += axolotl::pickle_length(value.alice_identity_key.key);
+    length += axolotl::pickle_length(value.alice_base_key);
+    length += axolotl::pickle_length(value.bob_one_time_key_id);
+    length += axolotl::pickle_length(value.ratchet);
+    return length;
+}
+
+
+std::uint8_t * axolotl::pickle(
+    std::uint8_t * pos,
+    Session const & value
+) {
+    pos = axolotl::pickle(pos, value.received_message);
+    pos = axolotl::pickle(pos, value.alice_identity_key.id);
+    pos = axolotl::pickle(pos, value.alice_identity_key.key);
+    pos = axolotl::pickle(pos, value.alice_base_key);
+    pos = axolotl::pickle(pos, value.bob_one_time_key_id);
+    pos = axolotl::pickle(pos, value.ratchet);
+    return pos;
+}
+
+
+std::uint8_t const * axolotl::unpickle(
+    std::uint8_t const * pos, std::uint8_t const * end,
+    Session & value
+) {
+    pos = axolotl::unpickle(pos, end, value.received_message);
+    pos = axolotl::unpickle(pos, end, value.alice_identity_key.id);
+    pos = axolotl::unpickle(pos, end, value.alice_identity_key.key);
+    pos = axolotl::unpickle(pos, end, value.alice_base_key);
+    pos = axolotl::unpickle(pos, end, value.bob_one_time_key_id);
+    pos = axolotl::unpickle(pos, end, value.ratchet);
+    return pos;
+}
+