RetroShare/libretroshare/src/serialiser/rsgxsmailitems.h
Gioacchino Mazzurco 54a0f87369 GxsMail implemented RSA encrypted mails sending
Add notice about param not being checked in GxsSecurity
Use proper types for RsGenExchange::getMsg* params
Implement bitwise or and not operators for t_RsGenericIdType
GxsMail unsubscribe old unused groups
GxsMail initial work on supporting client services
Implemented p3IdService::encryptData(...) for multiple recipients
2017-02-08 13:39:29 +01:00

276 lines
8.4 KiB
C++

#pragma once
/*
* GXS Mailing Service
* Copyright (C) 2016-2017 Gioacchino Mazzurco <gio@eigenlab.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string>
#include "rsgxsitems.h"
#include "serialiser/rsbaseserial.h"
#include "serialiser/rstlvidset.h"
#include "retroshare/rsgxsflags.h"
#include "retroshare/rsgxscircles.h" // For: GXS_CIRCLE_TYPE_PUBLIC
#include "services/p3idservice.h"
/// Values must fit into uint8_t
enum GxsMailItemsSubtypes
{
GXS_MAIL_SUBTYPE_MAIL = 1,
GXS_MAIL_SUBTYPE_ACK = 2,
GXS_MAIL_SUBTYPE_GROUP = 3
};
struct RsGxsMailBaseItem : RsGxsMsgItem
{
RsGxsMailBaseItem(GxsMailItemsSubtypes subtype) :
RsGxsMsgItem( RS_SERVICE_TYPE_GXS_MAIL,
static_cast<uint8_t>(subtype) ) {}
/// Values must fit into uint8_t
enum EncryptionMode
{
CLEAR_TEXT = 1,
RSA = 2,
UNDEFINED_ENCRYPTION = 250
};
EncryptionMode cryptoType;
/**
* @brief recipientsHint used instead of plain recipient id, so sender can
* decide the equilibrium between exposing the recipient and the cost of
* completely anonymize it. So a bunch of luky non recipient can conclude
* rapidly that they are not the recipient without trying to decrypt the
* message.
*
* To be able to decide how much metadata we disclose sending a message we
* send an hint instead of the recipient id in clear, the hint cannot be
* false (the recipient would discard the mail) but may be arbitrarly
* obscure like 0xFF...FF so potentially everyone could be the recipient, or
* may expose the complete recipient id or be a middle ground.
* To calculate arbitrary precise hint one do a bitwise OR of the recipients
* keys and an arbitrary salt, the more recipients has the mail and the more
* 1 bits has the salt the less accurate is the hint.
* This way the sender is able to adjust the metadata privacy needed for the
* message, in the more private case (recipientsHint == 0xFFF...FFF) no one
* has a clue about who is the actual recipient, while this imply the cost
* that every potencial recipient has to try to decrypt it to know if it is
* for herself. This way a bunch of non recipients can rapidly discover that
* the message is not directed to them without attempting it's decryption.
*
* To check if one id may be the recipient of the mail or not one need to
* bitwise compare the hint with the id, if at least one bit of the hint is
* 0 while the corrisponding bit in the id is 1 then the id cannot be the
* recipient of the mail.
*
* Note that by design one can prove that an id is not recipient of the mail
* but cannot prove it is.
* Also in the extreme case of using 0x00...00 as salt that is equivalent
* to not salting at all (aka the plain recipient id is used as hint) a
* malicious observer could not demostrate in a conclusive manner that the
* mail is directed to the actual recipient as the "apparently"
* corresponding hint may be fruit of a "luky" salting of another id.
*/
RsGxsId recipientsHint;
void inline saltRecipientHint(const RsGxsId& salt)
{ saltRecipientHint(recipientsHint, salt); }
void static inline saltRecipientHint(RsGxsId& hint, const RsGxsId& salt)
{ hint = hint | salt; }
/**
* @brief maybeRecipient given an id and an hint check if they match
* @see recipientHint
* @note this is not the final implementation as id and hint are not 32bit
* integers it is just to not forget how to verify the hint/id matching
* fastly with boolean ops
* @return true if the id may be recipient of the hint, false otherwise
*/
bool static inline maybeRecipient(const RsGxsId& hint, const RsGxsId& id)
{ return (~id|hint) == allRecipientsHint; }
const static RsGxsId allRecipientsHint;
void inline clear()
{
cryptoType = UNDEFINED_ENCRYPTION;
recipientsHint.clear();
meta = RsMsgMetaData();
}
static uint32_t inline size()
{
return 8 + // Header
1 + // cryptoType
RsGxsId::serial_size(); // recipientsHint
}
bool serialize(uint8_t* data, uint32_t size, uint32_t& offset) const;
bool deserialize(const uint8_t* data, uint32_t& size, uint32_t& offset);
std::ostream &print(std::ostream &out, uint16_t /*indent = 0*/);
};
struct RsGxsMailItem : RsGxsMailBaseItem
{
RsGxsMailItem(GxsMailItemsSubtypes subtype) :
RsGxsMailBaseItem(subtype) {}
RsGxsMailItem() :
RsGxsMailBaseItem(GXS_MAIL_SUBTYPE_MAIL) {}
/** This should travel encrypted, unless EncryptionMode::CLEAR_TEXT
* is specified */
std::vector<uint8_t> payload;
uint32_t size() const { return RsGxsMailBaseItem::size() + payload.size(); }
bool serialize(uint8_t* data, uint32_t size, uint32_t& offset) const
{
return size < MAX_SIZE
&& RsGxsMailBaseItem::serialize(data, size, offset)
&& memcpy(data+offset, &payload[0], payload.size());
}
bool deserialize(const uint8_t* data, uint32_t& size, uint32_t& offset)
{
uint32_t bsz = RsGxsMailBaseItem::size();
uint32_t psz = size - bsz;
return size < MAX_SIZE && size >= bsz
&& RsGxsMailBaseItem::deserialize(data, size, offset)
&& (payload.resize(psz), memcpy(&payload[0], data+offset, psz));
}
void clear() { RsGxsMailBaseItem::clear(); payload.clear(); }
/// Maximum mail size in bytes 10 MiB is more than anything sane can need
const static uint32_t MAX_SIZE = 10*8*1024*1024;
};
struct RsGxsMailAckItem : RsGxsMailBaseItem
{
RsGxsMailAckItem() : RsGxsMailBaseItem(GXS_MAIL_SUBTYPE_ACK) {}
RsGxsId recipient;
void clear() { recipient.clear(); }
std::ostream &print(std::ostream &out, uint16_t /*indent = 0*/)
{ return out << recipient.toStdString(); }
};
struct RsGxsMailGroupItem : RsGxsGrpItem
{
RsGxsMailGroupItem() :
RsGxsGrpItem(RS_SERVICE_TYPE_GXS_MAIL, GXS_MAIL_SUBTYPE_GROUP)
{
meta.mGroupFlags = GXS_SERV::FLAG_PRIVACY_PUBLIC;
meta.mGroupName = "Mail";
meta.mCircleType = GXS_CIRCLE_TYPE_PUBLIC;
}
void clear() {}
std::ostream &print(std::ostream &out, uint16_t /*indent = 0*/)
{ return out; }
};
struct RsGxsMailSerializer : RsSerialType
{
RsGxsMailSerializer() : RsSerialType( RS_PKT_VERSION_SERVICE,
RS_SERVICE_TYPE_GXS_MAIL ) {}
~RsGxsMailSerializer() {}
uint32_t size(RsItem* item)
{
uint32_t sz = 0;
switch(item->PacketSubType())
{
case GXS_MAIL_SUBTYPE_MAIL:
{
RsGxsMailItem* i = dynamic_cast<RsGxsMailItem*>(item);
if(i) sz = i->size();
break;
}
case GXS_MAIL_SUBTYPE_ACK:
{
RsGxsMailAckItem* i = dynamic_cast<RsGxsMailAckItem*>(item);
if(i)
{
sz = 8; // Header
sz += 4; // RsGxsMailBaseItem::recipient_hint
sz += 1; // RsGxsMailAckItem::read
sz += i->recipient.serial_size();
}
break;
}
case GXS_MAIL_SUBTYPE_GROUP: sz = 8; break;
default: break;
}
return sz;
}
bool serialise(RsItem* item, void* data, uint32_t* size);
RsItem* deserialise(void* data, uint32_t* size)
{
uint32_t rstype = getRsItemId(data);
uint32_t rssize = getRsItemSize(data);
uint8_t pktv = getRsItemVersion(rstype);
uint16_t srvc = getRsItemService(rstype);
if ( (RS_PKT_VERSION_SERVICE != pktv) || // 0x02
(RS_SERVICE_TYPE_GXS_MAIL != srvc) || // 0x0230 = 560
(*size < rssize) )
{
print_stacktrace();
return NULL;
}
*size = rssize;
bool ok = true;
RsItem* ret = NULL;
switch (getRsItemSubType(rstype))
{
case GXS_MAIL_SUBTYPE_MAIL:
{
RsGxsMailItem* i = new RsGxsMailItem();
uint32_t offset = 0;
const uint8_t* dataPtr = reinterpret_cast<uint8_t*>(data);
ok = ok && i->deserialize(dataPtr, *size, offset);
ret = i;
break;
}
case GXS_MAIL_SUBTYPE_ACK:
{
RsGxsMailAckItem* i = new RsGxsMailAckItem();
uint32_t offset = 0;
ok &= i->recipient.deserialise(data, *size, offset);
ret = i;
break;
}
case GXS_MAIL_SUBTYPE_GROUP:
{
ret = new RsGxsMailGroupItem();
break;
}
default:
ok = false;
break;
}
if(ok) return ret;
delete ret;
return NULL;
}
};