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Add methods for generating new one time keys and for tracking which one time keys have been published

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This commit is contained in:
Mark Haines 2015-07-09 16:09:16 +01:00
parent 0e988237f6
commit 5634be0507
2 changed files with 121 additions and 40 deletions
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88
include/olm/account.hh
View file

@ -31,6 +31,7 @@ struct IdentityKeys {
struct OneTimeKey {
std::uint32_t id;
bool published;
Curve25519KeyPair key;
};
@ -39,15 +40,17 @@ static std::size_t const MAX_ONE_TIME_KEYS = 100;
struct Account {
Account();
IdentityKeys identity_keys;
List<OneTimeKey, MAX_ONE_TIME_KEYS> one_time_keys;
std::uint32_t next_one_time_key_id;
ErrorCode last_error;
/** Number of random bytes needed to create a new account */
std::size_t new_account_random_length();
/** Create a new account. Returns NOT_ENOUGH_RANDOM if the number of random
* bytes is too small. */
/** Create a new account. Returns std::size_t(-1) on error. If the number of
* random bytes is too small then last_error will be NOT_ENOUGH_RANDOM */
std::size_t new_account(
uint8_t const * random, std::size_t random_length
);
@ -61,35 +64,30 @@ struct Account {
);
/** Output the identity keys for this account as JSON in the following
* format.
* format:
*
* 14 {"algorithms":
* 30 ["m.olm.curve25519-aes-sha256"
* 15 ],"device_id":"
* ? <device identifier>
* 22 ","keys":{"curve25519:
* 4 <base64 characters>
* 3 ":"
* 43 <base64 characters>
* 11 ","ed25519:
* 4 <base64 characters>
* 3 ":"
* 43 <base64 characters>
* 14 "},"user_id":"
* ? <user identifier>
* 19 ","valid_after_ts":
* ? <digits>
* 18 ,"valid_until_ts":
* ? <digits>
* 16 ,"signatures":{"
* ? <user identifier>
* 1 /
* ? <device identifier>
* 12 ":{"ed25519:
* 4 <base64 characters>
* 3 ":"
* 86 <base64 characters>
* 4 "}}}
* {"algorithms":
* ["m.olm.curve25519-aes-sha256"
* ]
* ,"device_id":"<device identifier>"
* ,"keys":
* {"curve25519:<key id>":"<base64 characters>"
* ,"ed25519:<key id>":"<base64 characters>"
* }
* ,"user_id":"<user identifier>"
* ,"valid_after_ts":<digits>
* ,"valid_until_ts":<digits>
* ,"signatures":
* {"<user identifier>/<device identifier>":
* {"ed25519:<key id>":"<base64 characters>"
* }
* }
* }
*
* The user_id and device_id must not contain 0x00-0x1F, '\"' or '\\'.
* The JSON up to but not including the "signatures" key will be signed
* using the account's ed25519 key. That signature is then included under
* the "signatures" key.
*
* Returns the size of the JSON written or std::size_t(-1) on error.
* If the buffer is too small last_error will be OUTPUT_BUFFER_TOO_SMALL. */
@ -104,7 +102,13 @@ struct Account {
/** Number of bytes needed to output the one time keys for this account */
std::size_t get_one_time_keys_json_length();
/*
/** Output the one time keys that haven't been published yet as JSON:
*
* {"curve25519:<key id>":"<base64 characters>"
* ,"curve25519:<key_id>":"<base64 characters>"
* ...
* }
*
* Returns the size of the JSON written or std::size_t(-1) on error.
* If the buffer is too small last_error will be OUTPUT_BUFFER_TOO_SMALL.
*/
@ -112,6 +116,28 @@ struct Account {
std::uint8_t * one_time_json, std::size_t one_time_json_length
);
/** Mark the current list of one_time_keys as being published. They
* will no longer be returned by get_one_time_keys_json_length(). */
std::size_t mark_keys_as_published();
/** The largest number of one time keys this account can store. */
std::size_t max_number_of_one_time_keys();
/** Returns the number of random bytes needed to generate a given number
* of new one time keys. */
std::size_t generate_one_time_keys_random_length(
std::size_t number_of_keys
);
/** Generates a number of new one time keys. If the total number of keys
* stored by this account exceeds max_number_of_one_time_keys() then the
* old keys are discarded. Returns std::size_t(-1) on error. If the number
* of random bytes is too small then last_error will be NOT_ENOUGH_RANDOM */
std::size_t generate_one_time_keys(
std::size_t number_of_keys,
std::uint8_t const * random, std::size_t random_length
);
/** Lookup a one time key with the given public key */
OneTimeKey const * lookup_key(
Curve25519PublicKey const & public_key

73
src/account.cpp
View file

@ -16,6 +16,11 @@
#include "olm/base64.hh"
#include "olm/pickle.hh"
olm::Account::Account(
) : next_one_time_key_id(0),
last_error(olm::ErrorCode::SUCCESS) {
}
olm::OneTimeKey const * olm::Account::lookup_key(
olm::Curve25519PublicKey const & public_key
@ -54,19 +59,12 @@ std::size_t olm::Account::new_account(
return std::size_t(-1);
}
unsigned id = 0;
olm::ed25519_generate_key(random, identity_keys.ed25519_key);
random += 32;
olm::curve25519_generate_key(random, identity_keys.curve25519_key);
random += 32;
for (unsigned i = 0; i < 10; ++i) {
OneTimeKey & key = *one_time_keys.insert(one_time_keys.end());
key.id = ++id;
olm::curve25519_generate_key(random, key.key);
random += 32;
}
generate_one_time_keys(10, random, random_length - 64);
return 0;
}
@ -236,6 +234,9 @@ std::size_t olm::Account::get_one_time_keys_json_length(
) {
std::size_t length = 0;
for (auto const & key : one_time_keys) {
if (key.published) {
continue;
}
length += 2; /* {" */
length += sizeof(ONE_TIME_KEY_JSON_ALG) - 1;
length += 1; /* : */
@ -262,6 +263,9 @@ std::size_t olm::Account::get_one_time_keys_json(
}
std::uint8_t sep = '{';
for (auto const & key : one_time_keys) {
if (key.published) {
continue;
}
*(pos++) = sep;
*(pos++) = '\"';
pos = write_string(pos, ONE_TIME_KEY_JSON_ALG);
@ -284,6 +288,48 @@ std::size_t olm::Account::get_one_time_keys_json(
}
std::size_t olm::Account::mark_keys_as_published(
) {
std::size_t count = 0;
for (auto & key : one_time_keys) {
if (!key.published) {
key.published = true;
count++;
}
}
return count;
}
std::size_t olm::Account::max_number_of_one_time_keys(
) {
return olm::MAX_ONE_TIME_KEYS;
}
std::size_t olm::Account::generate_one_time_keys_random_length(
std::size_t number_of_keys
) {
return 32 * number_of_keys;
}
std::size_t olm::Account::generate_one_time_keys(
std::size_t number_of_keys,
std::uint8_t const * random, std::size_t random_length
) {
if (random_length < generate_one_time_keys_random_length(number_of_keys)) {
last_error = olm::ErrorCode::NOT_ENOUGH_RANDOM;
return std::size_t(-1);
}
for (unsigned i = 0; i < number_of_keys; ++i) {
OneTimeKey & key = *one_time_keys.insert(one_time_keys.begin());
key.id = ++next_one_time_key_id;
key.published = false;
olm::curve25519_generate_key(random, key.key);
random += 32;
}
return number_of_keys;
}
namespace olm {
static std::size_t pickle_length(
@ -319,7 +365,11 @@ static std::uint8_t const * unpickle(
static std::size_t pickle_length(
olm::OneTimeKey const & value
) {
return olm::pickle_length(value.id) + olm::pickle_length(value.key);
std::size_t length = 0;
length += olm::pickle_length(value.id);
length += olm::pickle_length(value.published);
length += olm::pickle_length(value.key);
return length;
}
@ -328,6 +378,7 @@ static std::uint8_t * pickle(
olm::OneTimeKey const & value
) {
pos = olm::pickle(pos, value.id);
pos = olm::pickle(pos, value.published);
pos = olm::pickle(pos, value.key);
return pos;
}
@ -338,6 +389,7 @@ static std::uint8_t const * unpickle(
olm::OneTimeKey & value
) {
pos = olm::unpickle(pos, end, value.id);
pos = olm::unpickle(pos, end, value.published);
pos = olm::unpickle(pos, end, value.key);
return pos;
}
@ -351,6 +403,7 @@ std::size_t olm::pickle_length(
std::size_t length = 0;
length += olm::pickle_length(value.identity_keys);
length += olm::pickle_length(value.one_time_keys);
length += olm::pickle_length(value.next_one_time_key_id);
return length;
}
@ -361,6 +414,7 @@ std::uint8_t * olm::pickle(
) {
pos = olm::pickle(pos, value.identity_keys);
pos = olm::pickle(pos, value.one_time_keys);
pos = olm::pickle(pos, value.next_one_time_key_id);
return pos;
}
@ -371,5 +425,6 @@ std::uint8_t const * olm::unpickle(
) {
pos = olm::unpickle(pos, end, value.identity_keys);
pos = olm::unpickle(pos, end, value.one_time_keys);
pos = olm::unpickle(pos, end, value.next_one_time_key_id);
return pos;
}