Merge remote-tracking branch 'ahf/talla'

.gitignore

@@ -1,4 +1,5 @@
 .rebar
+.rebar3
 ebin
 *.beam
 *.o

Makefile

@@ -1,13 +1,9 @@
-REBAR=rebar
+REBAR=rebar3
 
 .PHONY: compile
-compile: deps
+compile:
 	$(REBAR) compile
 
-.PHONY: deps
-deps:
-	$(REBAR) get-deps
-
 .PHONY: clean
 clean:
 	$(REBAR) clean

c_src/Makefile

@@ -0,0 +1,69 @@
+# Based on c_src.mk from erlang.mk by Loïc Hoguin <essen@ninenines.eu>
+
+PROJECT ?= enacl_nif
+
+ERTS_INCLUDE_DIR ?= $(shell erl -noshell -s init stop -eval "io:format(\"~s/erts-~s/include/\", [code:root_dir(), erlang:system_info(version)]).")
+ERL_INTERFACE_INCLUDE_DIR ?= $(shell erl -noshell -s init stop -eval "io:format(\"~s\", [code:lib_dir(erl_interface, include)]).")
+ERL_INTERFACE_LIB_DIR ?= $(shell erl -noshell -s init stop -eval "io:format(\"~s\", [code:lib_dir(erl_interface, lib)]).")
+
+C_SRC_DIR = $(CURDIR)
+C_SRC_OUTPUT ?= $(CURDIR)/../priv/$(PROJECT).so
+
+# System type and C compiler/flags.
+
+UNAME_SYS := $(shell uname -s)
+ifeq ($(UNAME_SYS), Darwin)
+	CC ?= cc
+	CFLAGS ?= -O3 -std=c99 -arch x86_64 -finline-functions -Wall -Wmissing-prototypes
+	CXXFLAGS ?= -O3 -arch x86_64 -finline-functions -Wall
+	LDFLAGS ?= -arch x86_64 -flat_namespace -undefined suppress
+else ifeq ($(UNAME_SYS), FreeBSD)
+	CC ?= cc
+	CFLAGS ?= -O3 -std=c99 -finline-functions -Wall -Wmissing-prototypes
+	CXXFLAGS ?= -O3 -finline-functions -Wall
+else ifeq ($(UNAME_SYS), Linux)
+	CC ?= gcc
+	CFLAGS ?= -O3 -std=c99 -finline-functions -Wall -Wmissing-prototypes
+	CXXFLAGS ?= -O3 -finline-functions -Wall
+endif
+
+CFLAGS += -fPIC -I $(ERTS_INCLUDE_DIR) -I $(ERL_INTERFACE_INCLUDE_DIR)
+CXXFLAGS += -fPIC -I $(ERTS_INCLUDE_DIR) -I $(ERL_INTERFACE_INCLUDE_DIR)
+
+LDLIBS += -L $(ERL_INTERFACE_LIB_DIR) -lerl_interface -lei -lsodium
+LDFLAGS += -shared
+
+# Verbosity.
+
+c_verbose_0 = @echo " C     " $(?F);
+c_verbose = $(c_verbose_$(V))
+
+cpp_verbose_0 = @echo " CPP   " $(?F);
+cpp_verbose = $(cpp_verbose_$(V))
+
+link_verbose_0 = @echo " LD    " $(@F);
+link_verbose = $(link_verbose_$(V))
+
+SOURCES := $(shell find $(C_SRC_DIR) -type f \( -name "*.c" -o -name "*.C" -o -name "*.cc" -o -name "*.cpp" \))
+OBJECTS = $(addsuffix .o, $(basename $(SOURCES)))
+
+COMPILE_C = $(c_verbose) $(CC) $(CFLAGS) $(CPPFLAGS) -c
+COMPILE_CPP = $(cpp_verbose) $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c
+
+$(C_SRC_OUTPUT): $(OBJECTS)
+	$(link_verbose) $(CC) $(OBJECTS) $(LDFLAGS) $(LDLIBS) -o $(C_SRC_OUTPUT)
+
+%.o: %.c
+	$(COMPILE_C) $(OUTPUT_OPTION) $<
+
+%.o: %.cc
+	$(COMPILE_CPP) $(OUTPUT_OPTION) $<
+
+%.o: %.C
+	$(COMPILE_CPP) $(OUTPUT_OPTION) $<
+
+%.o: %.cpp
+	$(COMPILE_CPP) $(OUTPUT_OPTION) $<
+
+clean:
+	@rm $(C_SRC_OUTPUT) $(OBJECTS)

c_src/enacl_nif.c

@@ -79,6 +79,44 @@ ERL_NIF_TERM enif_crypto_verify_32(ErlNifEnv *env, int argc, ERL_NIF_TERM const
 	}
 }
 
+/* Curve 25519 */
+static
+ERL_NIF_TERM enif_crypto_curve25519_scalarmult(ErlNifEnv *env, int argc, ERL_NIF_TERM const argv[]) {
+	ERL_NIF_TERM result;
+	ErlNifBinary secret, basepoint, output;
+	uint8_t bp[crypto_scalarmult_curve25519_BYTES];
+
+	if ((argc != 2) || (!enif_inspect_binary(env, argv[0], &secret))
+			|| (!enif_inspect_binary(env, argv[1], &basepoint))
+			|| (secret.size != crypto_scalarmult_curve25519_BYTES)
+			|| (basepoint.size != crypto_scalarmult_curve25519_BYTES)) {
+		return enif_make_badarg(env);
+	}
+
+	memcpy(bp, basepoint.data, crypto_scalarmult_curve25519_BYTES);
+
+	/* Clear the high-bit. Better safe than sorry. */
+	bp[31] &= 0x7f;
+
+	do
+	{
+		if (!enif_alloc_binary(crypto_scalarmult_curve25519_BYTES, &output)) {
+			result = nacl_error_tuple(env, "alloc_failed");
+			continue;
+		}
+
+		if (crypto_scalarmult_curve25519(output.data, secret.data, bp) < 0) {
+			result = nacl_error_tuple(env, "scalarmult_curve25519_failed");
+			continue;
+		}
+
+		result = enif_make_binary(env, &output);
+	} while (0);
+
+	sodium_memzero(bp, crypto_scalarmult_curve25519_BYTES);
+
+	return result;
+}
 
 /* Public-key cryptography */
 static
@@ -807,6 +845,8 @@ static ErlNifFunc nif_funcs[] = {
 	{"crypto_verify_16", 2, enif_crypto_verify_16},
 	{"crypto_verify_32", 2, enif_crypto_verify_32},
 
+	{"crypto_curve25519_scalarmult", 2, enif_crypto_curve25519_scalarmult},
+
 	{"randombytes_b", 1, enif_randombytes},
 	{"randombytes", 1, enif_randombytes, ERL_NIF_DIRTY_JOB_CPU_BOUND},
 	

rebar.config

@@ -1,8 +1,6 @@
 {erl_opts, [debug_info]}.
 
-{port_env, [
-	{"CFLAGS", "$CFLAGS $LIBSODIUM_CFLAGS"},
-	{"LDFLAGS", "$LDFLAGS $LIBSODIUM_LDFLAGS -lsodium"}
+{pre_hooks, [
+	{compile, "make -C c_src"},
+	{clean, "make -C c_src clean"}
 ]}.
-
-{port_specs, [{"priv/enacl_nif.so", ["c_src/*.c"]}]}.

rebar.lock

@@ -0,0 +1 @@
+[].

src/enacl.erl

@@ -60,6 +60,11 @@
 	onetime_auth_verify/3
 ]).
 
+%% Curve 25519.
+-export([
+	curve25519_scalarmult/2
+]).
+
 %% Low-level functions
 -export([
 	hash/1,
@@ -591,6 +596,14 @@ onetime_auth_size() -> enacl_nif:crypto_onetimeauth_BYTES().
 -spec onetime_auth_key_size() -> pos_integer().
 onetime_auth_key_size() -> enacl_nif:crypto_onetimeauth_KEYBYTES().
 
+%% Curve 25519 Crypto
+%% ------------------
+%% @doc curve25519_scalarmult/2 does a scalar multiplication between the Secret and the BasePoint.
+%% @end.
+-spec curve25519_scalarmult(Secret :: binary(), BasePoint :: binary()) -> binary().
+curve25519_scalarmult(Secret, BasePoint) ->
+	enacl_nif:crypto_curve25519_scalarmult(Secret, BasePoint).
+
 %% Obtaining random bytes
 
 %% @doc randombytes/1 produces a stream of random bytes of the given size

src/enacl_ext.erl

@@ -9,6 +9,13 @@
 	scramble_block_16/2
 ]).
 
+%% Curve25519
+-export([
+	curve25519_keypair/0,
+	curve25519_public_key/1,
+	curve25519_shared/2
+]).
+
 %% @doc scramble_block_16/2 scrambles (encrypt) a block under a given key
 %% The rules are that the block is 16 bytes and the key is 32 bytes. The block
 %% is scrambled by means of the (secret) key. This makes it impossible for an
@@ -23,3 +30,29 @@
 -spec scramble_block_16(binary(), binary()) -> binary().
 scramble_block_16(Block, Key) ->
     enacl_nif:scramble_block_16(Block, Key).
+
+%% Curve 25519 Crypto
+%% ------------------
+%% @doc curve25519_keypair/0 creates a new Public/Secret keypair.
+%%
+%% Generates and returns a new key pair for the Curve 25519 encryption scheme. The return value is a
+%% map in order to avoid using the public key as a secret key and vice versa.
+%% @end.
+-spec curve25519_keypair() -> #{ atom() => binary() }.
+curve25519_keypair() ->
+	<<B0:8/integer, B1:30/binary, B2:8/integer>> = enacl:randombytes(32),
+	SK = <<(B0 band 248), B1/binary, (64 bor (B2 band 127))>>,
+	PK = curve25519_public_key(SK),
+	#{ public => PK, secret => SK }.
+
+%% @doc curve25519_public_key/1 creates a public key from a given SecretKey.
+%% @end
+-spec curve25519_public_key(SecretKey :: binary()) -> binary().
+curve25519_public_key(SecretKey) ->
+	enacl:curve25519_scalarmult(SecretKey, <<9, 0:248>>).
+
+%% @doc curve25519_shared/2 creates a new shared secret from a given SecretKey and PublicKey.
+%% @end.
+-spec curve25519_shared(SecretKey :: binary(), PublicKey :: binary()) -> binary().
+curve25519_shared(SecretKey, PublicKey) ->
+	enacl:curve25519_scalarmult(SecretKey, PublicKey).

src/enacl_nif.erl

@@ -71,6 +71,11 @@
 	crypto_onetimeauth_verify_b/3
 ]).
 
+%% Curve25519
+-export([
+	crypto_curve25519_scalarmult/2
+]).
+
 %% Miscellaneous helper functions
 -export([
 	crypto_hash/1,
@@ -161,6 +166,8 @@ crypto_onetimeauth_b(_Msg, _Key) -> erlang:nif_error(nif_not_loaded).
 crypto_onetimeauth_verify(_Authenticator, _Msg, _Key) -> erlang:nif_error(nif_not_loaded).
 crypto_onetimeauth_verify_b(_Authenticator, _Msg, _Key) -> erlang:nif_error(nif_not_loaded).
 
+crypto_curve25519_scalarmult(_Secret, _BasePoint) -> erlang:nif_error(nif_not_loaded).
+
 crypto_hash(Input) when is_binary(Input) -> erlang:nif_error(nif_not_loaded).
 crypto_hash_b(Input) when is_binary(Input) -> erlang:nif_error(nif_not_loaded).
 crypto_verify_16(_X, _Y) -> erlang:nif_error(nif_not_loaded).