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src|python: Add legacy and threshold support (dashpay#12)
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* elements|privatekey: Make constructors public

* src|python: Add support for <0.1.29 behaviour

* schemes: Add AggregateSecure and VerifySecure

* schemes: Add LegacySchemeMPL

This scheme reflects the Sign/Verify behaviour of older bls-signatures library versions (<0.1.29).

* privatekey: Implement `PrivateKey` * `bn_t` operator

* threshold|build: Add support for threshold recovery

* test: Add tests for threshold features and legacy scheme
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@xdustinface
xdustinface authored Mar 17, 2021
1 parent 1776926 commit 3ba07cd
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Showing 14 changed files with 1,305 additions and 56 deletions.
2 changes: 1 addition & 1 deletion python-bindings/pythonbindings.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -418,7 +418,7 @@ PYBIND11_MODULE(blspy, m)
return G2Element::FromBytes(Bytes(data_ptr, G2Element::SIZE));
})
.def("generator", &G2Element::Generator)
.def("from_message", py::overload_cast<const std::vector<uint8_t>&, const uint8_t*, int>(&G2Element::FromMessage))
.def("from_message", py::overload_cast<const std::vector<uint8_t>&, const uint8_t*, int, bool>(&G2Element::FromMessage))
.def("negate", &G2Element::Negate)
.def(
"__deepcopy__",
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2 changes: 2 additions & 0 deletions src/CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,9 @@ add_library(blstmp ${HEADERS}
${CMAKE_CURRENT_SOURCE_DIR}/privatekey.cpp
${CMAKE_CURRENT_SOURCE_DIR}/bls.cpp
${CMAKE_CURRENT_SOURCE_DIR}/elements.cpp
${CMAKE_CURRENT_SOURCE_DIR}/legacy.cpp
${CMAKE_CURRENT_SOURCE_DIR}/schemes.cpp
${CMAKE_CURRENT_SOURCE_DIR}/threshold.cpp
)

set(OPREFIX object_)
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1 change: 1 addition & 0 deletions src/bls.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@
#include "elements.hpp"
#include "hkdf.hpp"
#include "hdkeys.hpp"
#include "threshold.hpp"

namespace bls {

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123 changes: 83 additions & 40 deletions src/elements.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -15,10 +15,11 @@
#include <cstring>

#include "bls.hpp"
#include "legacy.hpp"

namespace bls {

G1Element G1Element::FromBytes(const Bytes& bytes)
G1Element G1Element::FromBytes(const Bytes& bytes, bool fLegacy)
{
if (bytes.size() != SIZE) {
throw std::invalid_argument("G1Element::FromBytes: Invalid size");
Expand All @@ -29,8 +30,6 @@ G1Element G1Element::FromBytes(const Bytes& bytes)
// convert bytes to relic form
uint8_t buffer[G1Element::SIZE + 1];
std::memcpy(buffer + 1, bytes.begin(), G1Element::SIZE);
buffer[0] = 0x00;
buffer[1] &= 0x1f; // erase 3 msbs from given input

if ((bytes[0] & 0xc0) == 0xc0) { // representing infinity
// enforce that infinity must be 0xc0000..00
Expand All @@ -46,25 +45,37 @@ G1Element G1Element::FromBytes(const Bytes& bytes)
}
return ele;
} else {
if ((bytes[0] & 0xc0) != 0x80) {
throw std::invalid_argument(
"Given G1 non-infinity element must start with 0b10");
}

if (bytes[0] & 0x20) { // sign bit
buffer[0] = 0x03;
if (fLegacy) {
if (bytes[0] & 0x80) {
buffer[0] = 0x03; // Insert extra byte for Y=1
buffer[1] &= 0x7f; // Remove initial Y bit
} else {
buffer[0] = 0x02; // Insert extra byte for Y=0
}
} else {
buffer[0] = 0x02;
buffer[0] = 0x00;
buffer[1] &= 0x1f; // erase 3 msbs from given input

if ((bytes[0] & 0xc0) != 0x80) {
throw std::invalid_argument(
"Given G1 non-infinity element must start with 0b10");
}

if (bytes[0] & 0x20) { // sign bit
buffer[0] = 0x03;
} else {
buffer[0] = 0x02;
}
}
}
g1_read_bin(ele.p, buffer, G1Element::SIZE + 1);
ele.CheckValid();
return ele;
}

G1Element G1Element::FromByteVector(const std::vector<uint8_t>& bytevec)
G1Element G1Element::FromByteVector(const std::vector<uint8_t>& bytevec, bool fLegacy)
{
return G1Element::FromBytes(Bytes(bytevec));
return G1Element::FromBytes(Bytes(bytevec), fLegacy);
}

G1Element G1Element::FromNative(const g1_t element)
Expand Down Expand Up @@ -142,7 +153,7 @@ uint32_t G1Element::GetFingerprint() const
return Util::FourBytesToInt(hash);
}

std::vector<uint8_t> G1Element::Serialize() const {
std::vector<uint8_t> G1Element::Serialize(const bool fLegacy) const {
uint8_t buffer[G1Element::SIZE + 1];
g1_write_bin(buffer, G1Element::SIZE + 1, p, 1);

Expand All @@ -153,10 +164,12 @@ std::vector<uint8_t> G1Element::Serialize() const {
}

if (buffer[0] == 0x03) { // sign bit set
buffer[1] |= 0x20;
buffer[1] |= fLegacy ? 0x80 : 0x20;
}

buffer[1] |= 0x80; // indicate compression
if (!fLegacy) {
buffer[1] |= 0x80; // indicate compression
}
return std::vector<uint8_t>(buffer + 1, buffer + 1 + G1Element::SIZE);
}

Expand Down Expand Up @@ -203,22 +216,26 @@ G1Element operator*(const bn_t& k, const G1Element& a) { return a * k; }



G2Element G2Element::FromBytes(const Bytes& bytes)
G2Element G2Element::FromBytes(const Bytes& bytes, const bool fLegacy)
{
if (bytes.size() != SIZE) {
throw std::invalid_argument("G2Element::FromBytes: Invalid size");
}

G2Element ele;
uint8_t buffer[G2Element::SIZE + 1];
std::memcpy(buffer + 1, bytes.begin() + G2Element::SIZE / 2, G2Element::SIZE / 2);
std::memcpy(buffer + 1 + G2Element::SIZE / 2, bytes.begin(), G2Element::SIZE / 2);
buffer[0] = 0x00;
buffer[49] &= 0x1f; // erase 3 msbs from input

if ((bytes[48] & 0xe0) != 0x00) {
throw std::invalid_argument(
"Given G2 element must always have 48th byte start with 0b000");
if (fLegacy) {
std::memcpy(buffer + 1, bytes.begin(), G2Element::SIZE);
} else {
std::memcpy(buffer + 1, bytes.begin() + G2Element::SIZE / 2, G2Element::SIZE / 2);
std::memcpy(buffer + 1 + G2Element::SIZE / 2, bytes.begin(), G2Element::SIZE / 2);
buffer[0] = 0x00;
buffer[49] &= 0x1f; // erase 3 msbs from input
if ((bytes[48] & 0xe0) != 0x00) {
throw std::invalid_argument(
"Given G2 element must always have 48th byte start with 0b000");
}
}
if (((bytes[0] & 0xc0) == 0xc0)) { // infinity
// enforce that infinity must be 0xc0000..00
Expand All @@ -233,6 +250,15 @@ G2Element G2Element::FromBytes(const Bytes& bytes)
}
}
return ele;
}

if (fLegacy) {
if (bytes[0] & 0x80) {
buffer[0] = 0x03; // Insert extra byte for Y=1
buffer[1] &= 0x7f; // Remove initial Y bit
} else {
buffer[0] = 0x02; // Insert extra byte for Y=0
}
} else {
if (((bytes[0] & 0xc0) != 0x80)) {
throw std::invalid_argument(
Expand All @@ -250,9 +276,9 @@ G2Element G2Element::FromBytes(const Bytes& bytes)
return ele;
}

G2Element G2Element::FromByteVector(const std::vector<uint8_t>& bytevec)
G2Element G2Element::FromByteVector(const std::vector<uint8_t>& bytevec, bool fLegacy)
{
return G2Element::FromBytes(Bytes(bytevec));
return G2Element::FromBytes(Bytes(bytevec), fLegacy);
}

G2Element G2Element::FromNative(const g2_t element)
Expand All @@ -265,17 +291,23 @@ G2Element G2Element::FromNative(const g2_t element)

G2Element G2Element::FromMessage(const std::vector<uint8_t>& message,
const uint8_t* dst,
int dst_len)
int dst_len,
const bool fLegacy)
{
return FromMessage(Bytes(message), dst, dst_len);
return FromMessage(Bytes(message), dst, dst_len, fLegacy);
}

G2Element G2Element::FromMessage(const Bytes& message,
const uint8_t* dst,
int dst_len)
int dst_len,
const bool fLegacy)
{
G2Element ans;
ep2_map_dst(ans.q, message.begin(), (int)message.size(), dst, dst_len);
if (fLegacy) {
ep2_map_legacy(ans.q, message.begin(), BLS::MESSAGE_HASH_LEN);
} else {
ep2_map_dst(ans.q, message.begin(), (int)message.size(), dst, dst_len);
}
ans.CheckValid();
return ans;
}
Expand Down Expand Up @@ -321,7 +353,7 @@ G2Element G2Element::Negate() const
return ans;
}

std::vector<uint8_t> G2Element::Serialize() const {
std::vector<uint8_t> G2Element::Serialize(const bool fLegacy) const {
uint8_t buffer[G2Element::SIZE + 1];
g2_write_bin(buffer, G2Element::SIZE + 1, (g2_st*)q, 1);

Expand All @@ -331,19 +363,30 @@ std::vector<uint8_t> G2Element::Serialize() const {
return result;
}

// remove leading 3 bits
buffer[1] &= 0x1f;
buffer[49] &= 0x1f;
if (buffer[0] == 0x03) {
buffer[49] |= 0xa0; // swapped later to 0
if (fLegacy) {
if (buffer[0] == 0x03) { // sign bit set
buffer[1] |= 0x80;
}
} else {
buffer[49] |= 0x80;
// remove leading 3 bits
buffer[1] &= 0x1f;
buffer[49] &= 0x1f;
if (buffer[0] == 0x03) {
buffer[49] |= 0xa0; // swapped later to 0
} else {
buffer[49] |= 0x80;
}
}

// Swap buffer, relic uses the opposite ordering for Fq2 elements
std::vector<uint8_t> result(G2Element::SIZE, 0);
std::memcpy(result.data(), buffer + 1 + G2Element::SIZE / 2, G2Element::SIZE / 2);
std::memcpy(result.data() + G2Element::SIZE / 2, buffer + 1, G2Element::SIZE / 2);
if (fLegacy) {
std::memcpy(result.data(), buffer + 1, G2Element::SIZE);
} else {
// Swap buffer, relic uses the opposite ordering for Fq2 elements
std::memcpy(result.data(), buffer + 1 + G2Element::SIZE / 2, G2Element::SIZE / 2);
std::memcpy(result.data() + G2Element::SIZE / 2, buffer + 1, G2Element::SIZE / 2);
}

return result;
}

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18 changes: 10 additions & 8 deletions src/elements.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -39,8 +39,8 @@ class G1Element {
g1_set_infty(p);
}

static G1Element FromBytes(const Bytes& bytes);
static G1Element FromByteVector(const std::vector<uint8_t> &bytevec);
static G1Element FromBytes(const Bytes& bytes, bool fLegacy = false);
static G1Element FromByteVector(const std::vector<uint8_t> &bytevec, bool fLegacy = false);
static G1Element FromNative(const g1_t element);
static G1Element FromMessage(const std::vector<uint8_t> &message,
const uint8_t *dst,
Expand All @@ -54,7 +54,7 @@ class G1Element {
void ToNative(g1_t output) const;
G1Element Negate() const;
uint32_t GetFingerprint() const;
std::vector<uint8_t> Serialize() const;
std::vector<uint8_t> Serialize(bool fLegacy = false) const;

friend bool operator==(const G1Element &a, const G1Element &b);
friend bool operator!=(const G1Element &a, const G1Element &b);
Expand All @@ -76,21 +76,23 @@ class G2Element {
g2_set_infty(q);
}

static G2Element FromBytes(const Bytes& bytes);
static G2Element FromByteVector(const std::vector<uint8_t> &bytevec);
static G2Element FromBytes(const Bytes& bytes, bool fLegacy = false);
static G2Element FromByteVector(const std::vector<uint8_t> &bytevec, bool fLegacy = false);
static G2Element FromNative(const g2_t element);
static G2Element FromMessage(const std::vector<uint8_t>& message,
const uint8_t* dst,
int dst_len);
int dst_len,
bool fLegacy = false);
static G2Element FromMessage(const Bytes& message,
const uint8_t* dst,
int dst_len);
int dst_len,
bool fLegacy = false);
static G2Element Generator();

void CheckValid() const;
void ToNative(g2_t output) const;
G2Element Negate() const;
std::vector<uint8_t> Serialize() const;
std::vector<uint8_t> Serialize(bool fLegacy = false) const;

friend bool operator==(G2Element const &a, G2Element const &b);
friend bool operator!=(G2Element const &a, G2Element const &b);
Expand Down
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