From 6a39173d1ebf8f0d34be356dd7253b5b67b3e9f4 Mon Sep 17 00:00:00 2001
From: Andrey Mayorov <a.mayorov@rbkmoney.com>
Date: Wed, 1 Mar 2017 23:02:32 +0300
Subject: [PATCH] Initial commit

---
 .gitignore              |  1 +
 rebar.config            |  1 +
 rebar.lock              |  1 +
 src/genecpubkey.app.src | 17 +++++++++++++++++
 src/genecpubkey.erl     | 16 ++++++++++++++++
 5 files changed, 36 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 rebar.config
 create mode 100644 rebar.lock
 create mode 100644 src/genecpubkey.app.src
 create mode 100644 src/genecpubkey.erl

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..e35d885
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+_build
diff --git a/rebar.config b/rebar.config
new file mode 100644
index 0000000..80ca3fb
--- /dev/null
+++ b/rebar.config
@@ -0,0 +1 @@
+{escript_emu_args, "%%! +sbtu +A0 -noshell -boot start_clean\n"}.
diff --git a/rebar.lock b/rebar.lock
new file mode 100644
index 0000000..57afcca
--- /dev/null
+++ b/rebar.lock
@@ -0,0 +1 @@
+[].
diff --git a/src/genecpubkey.app.src b/src/genecpubkey.app.src
new file mode 100644
index 0000000..57108f7
--- /dev/null
+++ b/src/genecpubkey.app.src
@@ -0,0 +1,17 @@
+{application, genecpubkey, [
+    {description, "Generate PEM file with EC Public key from EC Private key"},
+    {vsn, "0"},
+    {registered, []},
+    {applications, [
+        kernel,
+        stdlib,
+        public_key
+    ]},
+    {env, []},
+    {modules, []},
+    {maintainers, [
+        "Andrew Mayorov <a.mayorov@rbkmoney.com>"
+    ]},
+    {licenses, []},
+    {links, []}
+]}.
diff --git a/src/genecpubkey.erl b/src/genecpubkey.erl
new file mode 100644
index 0000000..50bbfb5
--- /dev/null
+++ b/src/genecpubkey.erl
@@ -0,0 +1,16 @@
+-module(genecpubkey).
+
+-export([main/1]).
+
+-spec main([string()]) -> no_return().
+
+main([PrivKeyPEMFilename, PubKeyPEMFilename]) ->
+    {ok, PrivKeyPEMBin} = file:read_file(PrivKeyPEMFilename),
+    [PrivKeyPEMEntry] = public_key:pem_decode(PrivKeyPEMBin),
+    [PrivKeyPEMEntry] = public_key:pem_decode(PrivKeyPEMBin),
+    PrivKey = public_key:pem_entry_decode(PrivKeyPEMEntry),
+    {'ECPrivateKey', 1, _, ECParams, PublicKey} = PrivKey,
+    PubKey = {{'ECPoint', PublicKey}, ECParams},
+    PubKeyPEMEntry = public_key:pem_entry_encode('SubjectPublicKeyInfo', PubKey),
+    PubKeyPEMBin = public_key:pem_encode([PubKeyPEMEntry]),
+    ok = file:write_file(PubKeyPEMFilename, PubKeyPEMBin).