From e73f2551feee690e9b17a077ad6131ee753cab11 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adrien=20B=C3=A9raud?= <adrien.beraud@savoirfairelinux.com>
Date: Wed, 25 Oct 2017 12:36:03 +0200
Subject: [PATCH] ringaccount: use base36 PIN for archive export
* Use base36 [0-9A-Z] instead of base16 (hex)
for PIN generation.
This increase the number of combinations from
2^32 to ~2^41.36, an increase of ~9.36 bits.
This increase should offset the entropy loss
due to the optional password.
* Use random_device directly instead of the
account (seeded) pseudo-generator because the PIN
should have cryptographic-level randomness.
Change-Id: I00169f5d08f6794329a9e9e22b7173a0a6ef9ef4
---
src/ringdht/ringaccount.cpp | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/src/ringdht/ringaccount.cpp b/src/ringdht/ringaccount.cpp
index 40c4d566c9..796b81ed04 100644
--- a/src/ringdht/ringaccount.cpp
+++ b/src/ringdht/ringaccount.cpp
@@ -981,6 +981,19 @@ RingAccount::computeKeys(const std::string& password, const std::string& pin, bo
return {key, loc};
}
+std::string
+generatePIN(size_t length = 8)
+{
+ static constexpr const char alphabet[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+ dht::crypto::random_device rd;
+ std::uniform_int_distribution<size_t> dis(0, sizeof(alphabet)-2);
+ std::string ret;
+ ret.reserve(length);
+ for (size_t i=0; i<length; i++)
+ ret.push_back(alphabet[dis(rd)]);
+ return ret;
+}
+
void
RingAccount::addDevice(const std::string& password)
{
@@ -995,14 +1008,8 @@ RingAccount::addDevice(const std::string& password)
a = this_->readArchive(password);
- // Generate random 32bits PIN
- std::uniform_int_distribution<uint32_t> dis;
- auto pin = dis(this_->rand_);
- // Manipulate PIN as hex
- std::stringstream ss;
- ss << std::hex << pin;
- pin_str = ss.str();
- std::transform(pin_str.begin(), pin_str.end(), pin_str.begin(), ::toupper);
+ // Generate random PIN
+ pin_str = generatePIN();
std::tie(key, loc) = computeKeys(password, pin_str);
} catch (const std::exception& e) {
@@ -3295,4 +3302,3 @@ RingAccount::registerDhtAddress(IceTransport& ice)
}
} // namespace ring
-
--
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