Adding the rsa.lua code to lcrypt.

3 files changed, 117 insertions, 1 deletions

diff --git a/lcrypt/Makefile b/lcrypt/Makefile
index ea1ac3b..0347ee8 100644
--- a/lcrypt/Makefile
+++ b/lcrypt/Makefile
@@ -1,6 +1,6 @@
 CFLAGS += -O3 -Wall -DLITTLE_ENDIAN -DLTM_DESC -DLTC_SOURCE -DUSE_LTM -fPIC -I$(TOMCRYPT)/src/headers -I$(LUA)/src -I../src
 
-lcrypt.o: lcrypt.c lcrypt_ciphers.c lcrypt_hashes.c lcrypt_math.c lcrypt_bits.c
+lcrypt.o: lcrypt.c lcrypt_ciphers.c lcrypt_hashes.c lcrypt_math.c lcrypt_bits.c lcrypt_rsa.c
 	$(CC) $(CFLAGS) -c lcrypt.c -o $@
 
 clean:
diff --git a/lcrypt/lcrypt.c b/lcrypt/lcrypt.c
index d757f11..ed514dd 100644
--- a/lcrypt/lcrypt.c
+++ b/lcrypt/lcrypt.c
@@ -54,6 +54,7 @@ static void* lcrypt_malloc(lua_State *L, size_t size)
 #include "lcrypt_hashes.c"
 #include "lcrypt_math.c"
 #include "lcrypt_bits.c"
+#include "lcrypt_rsa.c"
 
 static int lcrypt_tohex(lua_State *L)
 {
diff --git a/lcrypt/lcrypt_rsa.c b/lcrypt/lcrypt_rsa.c
new file mode 100644
index 0000000..77ea4a2
--- /dev/null
+++ b/lcrypt/lcrypt_rsa.c
@@ -0,0 +1,115 @@
+const char * lcrypt_rsa = ""
+"rsa = {}\n"
+"\n"
+"function rsa:pkcs1_pad(data, out_length)\n"
+"  local asn1 = string.char(0x00, 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14)\n"
+"  return string.char(0x00, 0x01) .. string.char(0xff):rep(out_length - #asn1 - #data - 2) .. asn1 .. data\n"
+"end\n"
+"\n"
+"function rsa:encode_int(value, len)\n"
+"  local ret = ''\n"
+"  for i=1,len do\n"
+"    ret = string.char(value % 256) .. ret\n"
+"    value = math.floor(value / 256)\n"
+"  end\n"
+"  return ret\n"
+"end\n"
+"\n"
+"function rsa:oaep_g(data, out_length)\n"
+"  local out,counter = '', 0\n"
+"  while #out < out_length do\n"
+"    out = out .. lcrypt.hashes.sha1:hash(data .. self:encode_int(counter, 4)):done()\n"
+"    counter = counter + 1\n"
+"  end\n"
+"  return out:sub(1, out_length)\n"
+"end\n"
+"\n"
+"function rsa:oaep_pad(data, param, out_length)\n"
+"  out_length = out_length - 1\n"
+"  local h_length = #data\n"
+"  local g_length = out_length - h_length\n"
+"  local seed = lcrypt.random(h_length)\n"
+"  local c = lcrypt.hashes.sha1:hash(param):done()\n"
+"  c = c .. string.rep(string.char(0), g_length - h_length - 2 - #c) .. string.char(0, 1) .. data\n"
+"  local x = lcrypt.xor(c, self:oaep_g(seed, g_length))\n"
+"  local y = lcrypt.xor(seed, self:oaep_g(x, h_length))\n"
+"  return string.char(0) .. x .. y\n"
+"end\n"
+"\n"
+"function rsa:oaep_unpad(data, param, out_length)\n"
+"  data = data:sub(2, #data)\n"
+"  local g_length = #data - out_length\n"
+"  local x = data:sub(1, g_length)\n"
+"  local seed = lcrypt.xor(self:oaep_g(x, out_length), data:sub(g_length +1, #data))\n"
+"  local c = lcrypt.xor(x, self:oaep_g(seed, g_length))\n"
+"  local v = lcrypt.hashes.sha1:hash(param):done()\n"
+"  if c:sub(1,#v) == v then return c:sub(g_length - out_length + 1, #c) end\n"
+"end\n"
+"\n"
+"function rsa:prime(bits)\n"
+"  bits = math.floor(bits)\n"
+"  if bits < 24 then return end\n"
+"  local ret, high, bytes = nil, 1, math.floor((bits - 7) / 8)\n"
+"  for i=1,bits-bytes*8-1 do high = 1 + high + high end\n"
+"  high = string.char(high)\n"
+"  low = lcrypt.random(1):byte()\n"
+"  if low / 2 == math.floor(low / 2) then low = low + 1 end\n"
+"  low = string.char(low)\n"
+"  bytes = bytes - 1\n"
+"  repeat\n"
+"    ret = lcrypt.bigint(high .. lcrypt.random(bytes) .. low)\n"
+"  until ret.isprime\n"
+"  return ret\n"
+"end\n"
+"\n"
+"function rsa:gen_key(bits, e)\n"
+"  local key,one,p1,q1 = { e=lcrypt.bigint(e) }, lcrypt.bigint(1), nil, nil\n"
+"  bits = bits / 2\n"
+"  repeat\n"
+"    key.p = self:prime(bits)\n"
+"    p1 = key.p - one\n"
+"  until p1:gcd(key.e) == one\n"
+"  repeat\n"
+"    key.q = self:prime(bits)\n"
+"    q1 = key.q - one\n"
+"  until q1:gcd(key.e) == one\n"
+"  key.d = key.e:invmod(p1:lcm(q1))\n"
+"  key.n = key.p * key.q\n"
+"  key.dp = key.d % p1\n"
+"  key.dq = key.d % q1\n"
+"  key.qp = key.q:invmod(key.p)\n"
+"  return key\n"
+"end\n"
+"\n"
+"function rsa:private(msg, key)\n"
+"  msg = lcrypt.bigint(msg)\n"
+"  local a,b = msg:exptmod(key.dp, key.p), msg:exptmod(key.dq, key.q)\n"
+"  local ret = tostring(key.qp:mulmod(a - b, key.p) * key.q + b)\n"
+"  if ret:byte(1) == 0 then ret = ret:sub(2, #ret) end\n"
+"  return ret\n"
+"end\n"
+"\n"
+"function rsa:public(msg, key)\n"
+"  return tostring(lcrypt.bigint(msg):exptmod(key.e, key.n))\n"
+"end\n"
+"\n"
+"function rsa:sign_pkcs1(msg, key)\n"
+"  return self:private(self:pkcs1_pad(lcrypt.hashes.sha1:hash(msg):done(), key.n.bits / 8), key)\n"
+"end\n"
+"\n"
+"function rsa:verify_pkcs1(signature, msg, key)\n"
+"  msg = lcrypt.hashes.sha1:hash(msg):done()\n"
+"  local tmp = self:public(signature, key)\n"
+"  if tmp:sub(#tmp - #msg + 1, #tmp) == msg then return true end\n"
+"end\n"
+"\n"
+"function rsa:sign_oaep(msg, param, key)\n"
+"  return self:private(self:oaep_pad(lcrypt.hashes.sha1:hash(msg):done(), param, key.n.bits / 8), key)\n"
+"end\n"
+"\n"
+"function rsa:verify_oaep(signature, msg, param, key)\n"
+"  local tmp = self:public(signature, key)\n"
+"  local h = self:oaep_unpad(tmp, param, 20)\n"
+"  if h == lcrypt.hashes.sha1:hash(msg):done() then return true end\n"
+"end\n"
+"";