--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/spec/util_crypto_spec.lua Fri Jun 24 16:56:16 2022 +0100
@@ -0,0 +1,196 @@
+local test_keys = {
+ ecdsa_private_pem = [[
+-----BEGIN PRIVATE KEY-----
+MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQg7taVK6bPtPz4ah32
+aD9CfvOah5omBxRVtzypwQXvZeahRANCAAQpKFeNIy27+lVo6bJslO6r2ty5rlb5
+xEiCx8GrrbJ8S7b5IPZCS7OrBaO2iqgOf7NMsgO12eLCfMZRnA+gCC34
+-----END PRIVATE KEY-----
+]];
+
+ ecdsa_public_pem = [[
+-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEKShXjSMtu/pVaOmybJTuq9rcua5W
++cRIgsfBq62yfEu2+SD2QkuzqwWjtoqoDn+zTLIDtdniwnzGUZwPoAgt+A==
+-----END PUBLIC KEY-----
+]];
+
+ eddsa_private_pem = [[
+-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEIOmrajEfnqdzdJzkJ4irQMCGbYRqrl0RlwPHIw+a5b7M
+-----END PRIVATE KEY-----
+]];
+
+ eddsa_public_pem = [[
+-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEAFipbSXeGvPVK7eA4+hIOdutZTUUyXswVSbMGi0j1QKE=
+-----END PUBLIC KEY-----
+]];
+
+};
+
+describe("util.crypto", function ()
+ local crypto = require "util.crypto";
+ local random = require "util.random";
+
+ describe("generate_ed25519_keypair", function ()
+ local keypair = crypto.generate_ed25519_keypair();
+ assert.is_not_nil(keypair);
+ assert.equal("ED25519", keypair:get_type());
+ end)
+
+ describe("import_private_pem", function ()
+ it("can import ECDSA keys", function ()
+ local ecdsa_key = crypto.import_private_pem(test_keys.ecdsa_private_pem);
+ assert.equal("id-ecPublicKey", ecdsa_key:get_type());
+ end);
+
+ it("can import EdDSA (Ed25519) keys", function ()
+ local ed25519_key = crypto.import_private_pem(crypto.generate_ed25519_keypair():private_pem());
+ assert.equal("ED25519", ed25519_key:get_type());
+ end);
+
+ it("can import RSA keys", function ()
+ -- TODO
+ end);
+
+ it("rejects invalid keys", function ()
+ assert.is_nil(crypto.import_private_pem(test_keys.eddsa_public_pem));
+ assert.is_nil(crypto.import_private_pem(test_keys.ecdsa_public_pem));
+ assert.is_nil(crypto.import_private_pem("foo"));
+ assert.is_nil(crypto.import_private_pem(""));
+ end);
+ end);
+
+ describe("import_public_pem", function ()
+ it("can import ECDSA public keys", function ()
+ local ecdsa_key = crypto.import_public_pem(test_keys.ecdsa_public_pem);
+ assert.equal("id-ecPublicKey", ecdsa_key:get_type());
+ end);
+
+ it("can import EdDSA (Ed25519) public keys", function ()
+ local ed25519_key = crypto.import_public_pem(test_keys.eddsa_public_pem);
+ assert.equal("ED25519", ed25519_key:get_type());
+ end);
+
+ it("can import RSA public keys", function ()
+ -- TODO
+ end);
+ end);
+
+ describe("PEM export", function ()
+ it("works", function ()
+ local ecdsa_key = crypto.import_public_pem(test_keys.ecdsa_public_pem);
+ assert.equal("id-ecPublicKey", ecdsa_key:get_type());
+ assert.equal(test_keys.ecdsa_public_pem, ecdsa_key:public_pem());
+
+ assert.has_error(function ()
+ -- Fails because private key is not available
+ ecdsa_key:private_pem();
+ end);
+
+ local ecdsa_private_key = crypto.import_private_pem(test_keys.ecdsa_private_pem);
+ assert.equal(test_keys.ecdsa_private_pem, ecdsa_private_key:private_pem());
+ end);
+ end);
+
+ describe("sign/verify with", function ()
+ local test_cases = {
+ ed25519 = {
+ crypto.ed25519_sign, crypto.ed25519_verify;
+ key = crypto.import_private_pem(test_keys.eddsa_private_pem);
+ sig_length = 64;
+ };
+ ecdsa = {
+ crypto.ecdsa_sha256_sign, crypto.ecdsa_sha256_verify;
+ key = crypto.import_private_pem(test_keys.ecdsa_private_pem);
+ };
+ };
+ for test_name, test in pairs(test_cases) do
+ local key = test.key;
+ describe(test_name, function ()
+ it("works", function ()
+ local sign, verify = test[1], test[2];
+ local sig = assert(sign(key, "Hello world"));
+ assert.is_string(sig);
+ if test.sig_length then
+ assert.equal(test.sig_length, #sig);
+ end
+
+ do
+ local ok = verify(key, "Hello world", sig);
+ assert.is_truthy(ok);
+ end
+ do -- Incorrect signature
+ local ok = verify(key, "Hello world", sig:sub(1, -2)..string.char((sig:byte(-1)+1)%255));
+ assert.is_falsy(ok);
+ end
+ do -- Incorrect message
+ local ok = verify(key, "Hello earth", sig);
+ assert.is_falsy(ok);
+ end
+ do -- Incorrect message (embedded NUL)
+ local ok = verify(key, "Hello world\0foo", sig);
+ assert.is_falsy(ok);
+ end
+ end);
+ end);
+ end
+ end);
+
+ describe("ECDSA signatures", function ()
+ local hex = require "util.hex";
+ local sig = hex.decode((([[
+ 304402203e936e7b0bc62887e0e9d675afd08531a930384cfcf301
+ f25d13053a2ebf141d02205a5a7c7b7ac5878d004cb79b17b39346
+ 6b0cd1043718ffc31c153b971d213a8e
+ ]]):gsub("%s+", "")));
+ it("can be parsed", function ()
+ local r, s = crypto.parse_ecdsa_signature(sig);
+ assert.is_string(r);
+ assert.is_string(s);
+ assert.equal(32, #r);
+ assert.equal(32, #s);
+ end);
+ it("fails to parse invalid signatures", function ()
+ local invalid_sigs = {
+ "";
+ "\000";
+ string.rep("\000", 64);
+ string.rep("\000", 72);
+ string.rep("\000", 256);
+ string.rep("\255", 72);
+ string.rep("\255", 3);
+ };
+ for _, sig in ipairs(invalid_sigs) do
+ local r, s = crypto.parse_ecdsa_signature("");
+ assert.is_nil(r);
+ assert.is_nil(s);
+ end
+
+ end);
+ it("can be built", function ()
+ local r, s = crypto.parse_ecdsa_signature(sig);
+ local rebuilt_sig = crypto.build_ecdsa_signature(r, s);
+ assert.equal(sig, rebuilt_sig);
+ end);
+ end);
+
+ describe("AES-GCM encryption", function ()
+ it("works", function ()
+ local message = "foo\0bar";
+ local key_128_bit = random.bytes(16);
+ local key_256_bit = random.bytes(32);
+ local test_cases = {
+ { crypto.aes_128_gcm_encrypt, crypto.aes_128_gcm_decrypt, key = key_128_bit };
+ { crypto.aes_256_gcm_encrypt, crypto.aes_256_gcm_decrypt, key = key_256_bit };
+ };
+ for _, params in pairs(test_cases) do
+ local iv = params.iv or random.bytes(12);
+ local encrypted = params[1](params.key, iv, message);
+ assert.not_equal(message, encrypted);
+ local decrypted = params[2](params.key, iv, encrypted);
+ assert.equal(message, decrypted);
+ end
+ end);
+ end);
+end);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/util-src/crypto.c Fri Jun 24 16:56:16 2022 +0100
@@ -0,0 +1,555 @@
+/* Prosody IM
+-- Copyright (C) 2022 Matthew Wild
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+*/
+
+/*
+* crypto.c
+* Lua library for cryptographic operations using OpenSSL
+*/
+
+#include <string.h>
+#include <stdlib.h>
+
+#ifdef _MSC_VER
+typedef unsigned __int32 uint32_t;
+#else
+#include <inttypes.h>
+#endif
+
+#include "lua.h"
+#include "lauxlib.h"
+#include <openssl/crypto.h>
+#include <openssl/ecdsa.h>
+#include <openssl/err.h>
+#include <openssl/evp.h>
+#include <openssl/obj_mac.h>
+#include <openssl/pem.h>
+
+#if (LUA_VERSION_NUM == 501)
+#define luaL_setfuncs(L, R, N) luaL_register(L, NULL, R)
+#endif
+
+#include "managed_pointer.h"
+
+#define PKEY_MT_TAG "util.crypto key"
+
+static BIO* new_memory_BIO() {
+ return BIO_new(BIO_s_mem());
+}
+
+MANAGED_POINTER_ALLOCATOR(new_managed_EVP_MD_CTX, EVP_MD_CTX*, EVP_MD_CTX_new, EVP_MD_CTX_free)
+MANAGED_POINTER_ALLOCATOR(new_managed_BIO_s_mem, BIO*, new_memory_BIO, BIO_free)
+MANAGED_POINTER_ALLOCATOR(new_managed_EVP_CIPHER_CTX, EVP_CIPHER_CTX*, EVP_CIPHER_CTX_new, EVP_CIPHER_CTX_free)
+
+static EVP_PKEY* pkey_from_arg(lua_State *L, int idx, const int type, const int require_private) {
+ EVP_PKEY *pkey = *(EVP_PKEY**)luaL_checkudata(L, idx, PKEY_MT_TAG);
+ if(type || require_private) {
+ lua_getuservalue(L, idx);
+ if(type != 0) {
+ lua_getfield(L, -1, "type");
+ if(lua_tointeger(L, -1) != type) {
+ luaL_argerror(L, idx, "unexpected key type");
+ }
+ lua_pop(L, 1);
+ }
+ if(require_private != 0) {
+ lua_getfield(L, -1, "private");
+ if(lua_toboolean(L, -1) != 1) {
+ luaL_argerror(L, idx, "private key expected, got public key only");
+ }
+ lua_pop(L, 1);
+ }
+ lua_pop(L, 1);
+ }
+ return pkey;
+}
+
+static int Lpkey_finalizer(lua_State *L) {
+ EVP_PKEY *pkey = pkey_from_arg(L, 1, 0, 0);
+ EVP_PKEY_free(pkey);
+ return 0;
+}
+
+static int Lpkey_meth_get_type(lua_State *L) {
+ EVP_PKEY *pkey = pkey_from_arg(L, 1, 0, 0);
+
+ int key_type = EVP_PKEY_id(pkey);
+ lua_pushstring(L, OBJ_nid2sn(key_type));
+ return 1;
+}
+
+static int base_evp_sign(lua_State *L, const int key_type, const EVP_MD *digest_type) {
+ EVP_PKEY *pkey = pkey_from_arg(L, 1, key_type, 1);
+ luaL_Buffer sigbuf;
+
+ size_t msg_len;
+ const unsigned char* msg = (unsigned char*)lua_tolstring(L, 2, &msg_len);
+
+ size_t sig_len;
+ unsigned char *sig = NULL;
+ EVP_MD_CTX *md_ctx = new_managed_EVP_MD_CTX(L);
+
+ if(EVP_DigestSignInit(md_ctx, NULL, digest_type, NULL, pkey) != 1) {
+ lua_pushnil(L);
+ return 1;
+ }
+ if(EVP_DigestSign(md_ctx, NULL, &sig_len, msg, msg_len) != 1) {
+ lua_pushnil(L);
+ return 1;
+ }
+
+ // COMPAT w/ Lua 5.1
+ luaL_buffinit(L, &sigbuf);
+ sig = memset(luaL_prepbuffer(&sigbuf), 0, sig_len);
+
+ if(EVP_DigestSign(md_ctx, sig, &sig_len, msg, msg_len) != 1) {
+ lua_pushnil(L);
+ }
+ else {
+ luaL_addsize(&sigbuf, sig_len);
+ luaL_pushresult(&sigbuf);
+ return 1;
+ }
+
+ return 1;
+}
+
+static int base_evp_verify(lua_State *L, const int key_type, const EVP_MD *digest_type) {
+ EVP_PKEY *pkey = pkey_from_arg(L, 1, key_type, 0);
+
+ size_t msg_len;
+ const unsigned char *msg = (unsigned char*)luaL_checklstring(L, 2, &msg_len);
+
+ size_t sig_len;
+ const unsigned char *sig = (unsigned char*)luaL_checklstring(L, 3, &sig_len);
+
+ EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
+
+ if(EVP_DigestVerifyInit(md_ctx, NULL, digest_type, NULL, pkey) != 1) {
+ lua_pushnil(L);
+ goto cleanup;
+ }
+ int result = EVP_DigestVerify(md_ctx, sig, sig_len, msg, msg_len);
+ if(result == 0) {
+ lua_pushboolean(L, 0);
+ } else if(result != 1) {
+ lua_pushnil(L);
+ }
+ else {
+ lua_pushboolean(L, 1);
+ }
+cleanup:
+ EVP_MD_CTX_free(md_ctx);
+ return 1;
+}
+
+static int Lpkey_meth_public_pem(lua_State *L) {
+ char *data;
+ size_t bytes;
+ EVP_PKEY *pkey = pkey_from_arg(L, 1, 0, 0);
+ BIO *bio = new_managed_BIO_s_mem(L);
+ if(PEM_write_bio_PUBKEY(bio, pkey)) {
+ bytes = BIO_get_mem_data(bio, &data);
+ if (bytes > 0) {
+ lua_pushlstring(L, data, bytes);
+ }
+ else {
+ lua_pushnil(L);
+ }
+ }
+ else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+static int Lpkey_meth_private_pem(lua_State *L) {
+ char *data;
+ size_t bytes;
+ EVP_PKEY *pkey = pkey_from_arg(L, 1, 0, 1);
+ BIO *bio = new_managed_BIO_s_mem(L);
+
+ if(PEM_write_bio_PrivateKey(bio, pkey, NULL, NULL, 0, NULL, NULL)) {
+ bytes = BIO_get_mem_data(bio, &data);
+ if (bytes > 0) {
+ lua_pushlstring(L, data, bytes);
+ }
+ else {
+ lua_pushnil(L);
+ }
+ }
+ else {
+ lua_pushnil(L);
+ }
+ return 1;
+}
+
+/* ecdsa_sha256_sign(key, data) */
+static int Lecdsa_sha256_sign(lua_State *L) {
+ return base_evp_sign(L, NID_X9_62_id_ecPublicKey, EVP_sha256());
+}
+
+/* ecdsa_sha256_verify(key, data, sig) */
+static int Lecdsa_sha256_verify(lua_State *L) {
+ return base_evp_verify(L, NID_X9_62_id_ecPublicKey, EVP_sha256());
+}
+
+static int push_pkey(lua_State *L, EVP_PKEY *pkey, const int type, const int privkey) {
+ EVP_PKEY **ud = lua_newuserdata(L, sizeof(EVP_PKEY*));
+ *ud = pkey;
+ luaL_newmetatable(L, PKEY_MT_TAG);
+ lua_setmetatable(L, -2);
+
+ /* Set some info about the key and attach it as a user value */
+ lua_newtable(L);
+ if(type != 0) {
+ lua_pushinteger(L, type);
+ lua_setfield(L, -2, "type");
+ }
+ if(privkey != 0) {
+ lua_pushboolean(L, 1);
+ lua_setfield(L, -2, "private");
+ }
+ lua_setuservalue(L, -2);
+ return 1;
+}
+
+static int Lgenerate_ed25519_keypair(lua_State *L) {
+ EVP_PKEY *pkey = NULL;
+ EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_ED25519, NULL);
+
+ /* Generate key */
+ EVP_PKEY_keygen_init(pctx);
+ EVP_PKEY_keygen(pctx, &pkey);
+ EVP_PKEY_CTX_free(pctx);
+
+ push_pkey(L, pkey, NID_ED25519, 1);
+ return 1;
+}
+
+static int Limport_private_pem(lua_State *L) {
+ EVP_PKEY *pkey = NULL;
+
+ size_t privkey_bytes;
+ const char* privkey_data;
+ BIO *bio = new_managed_BIO_s_mem(L);
+
+ privkey_data = luaL_checklstring(L, 1, &privkey_bytes);
+ BIO_write(bio, privkey_data, privkey_bytes);
+ pkey = PEM_read_bio_PrivateKey(bio, NULL, NULL, NULL);
+ if (pkey) {
+ push_pkey(L, pkey, EVP_PKEY_id(pkey), 1);
+ }
+ else {
+ lua_pushnil(L);
+ }
+
+ return 1;
+}
+
+static int Limport_public_pem(lua_State *L) {
+ EVP_PKEY *pkey = NULL;
+
+ size_t pubkey_bytes;
+ const char* pubkey_data;
+ BIO *bio = new_managed_BIO_s_mem(L);
+
+ pubkey_data = luaL_checklstring(L, 1, &pubkey_bytes);
+ BIO_write(bio, pubkey_data, pubkey_bytes);
+ pkey = PEM_read_bio_PUBKEY(bio, NULL, NULL, NULL);
+ if (pkey) {
+ push_pkey(L, pkey, EVP_PKEY_id(pkey), 0);
+ }
+ else {
+ lua_pushnil(L);
+ }
+
+ return 1;
+}
+
+static int Led25519_sign(lua_State *L) {
+ return base_evp_sign(L, NID_ED25519, NULL);
+}
+
+static int Led25519_verify(lua_State *L) {
+ return base_evp_verify(L, NID_ED25519, NULL);
+}
+
+/* gcm_encrypt(key, iv, plaintext) */
+static int Laes_gcm_encrypt(lua_State *L, const EVP_CIPHER *cipher, const unsigned char expected_key_len) {
+ EVP_CIPHER_CTX *ctx;
+ luaL_Buffer ciphertext_buffer;
+
+ size_t key_len, iv_len, plaintext_len;
+ int ciphertext_len, final_len;
+
+ const unsigned char *key = (unsigned char*)luaL_checklstring(L, 1, &key_len);
+ const unsigned char *iv = (unsigned char*)luaL_checklstring(L, 2, &iv_len);
+ const unsigned char *plaintext = (unsigned char*)luaL_checklstring(L, 3, &plaintext_len);
+
+ if(key_len != expected_key_len) {
+ return luaL_error(L, "key must be %d bytes", expected_key_len);
+ }
+ luaL_argcheck(L, iv_len == 12, 2, "iv must be 12 bytes");
+ if(lua_gettop(L) > 3) {
+ return luaL_error(L, "Expected 3 arguments, got %d", lua_gettop(L));
+ }
+
+ // Create and initialise the context
+ ctx = new_managed_EVP_CIPHER_CTX(L);
+
+ // Initialise the encryption operation
+ if(1 != EVP_EncryptInit_ex(ctx, cipher, NULL, NULL, NULL)) {
+ return luaL_error(L, "Error while initializing encryption engine");
+ }
+
+ // Initialise key and IV
+ if(1 != EVP_EncryptInit_ex(ctx, NULL, NULL, key, iv)) {
+ return luaL_error(L, "Error while initializing key/iv");
+ }
+
+ luaL_buffinit(L, &ciphertext_buffer);
+ unsigned char *ciphertext = (unsigned char*)luaL_prepbuffsize(&ciphertext_buffer, plaintext_len+16);
+
+ if(1 != EVP_EncryptUpdate(ctx, ciphertext, &ciphertext_len, plaintext, plaintext_len)) {
+ return luaL_error(L, "Error while encrypting data");
+ }
+
+ /*
+ * Finalise the encryption. Normally ciphertext bytes may be written at
+ * this stage, but this does not occur in GCM mode
+ */
+ if(1 != EVP_EncryptFinal_ex(ctx, ciphertext + ciphertext_len, &final_len)) {
+ return luaL_error(L, "Error while encrypting final data");
+ }
+ if(final_len != 0) {
+ return luaL_error(L, "Non-zero final data");
+ }
+
+ /* Get the tag */
+ if(1 != EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, 16, ciphertext + ciphertext_len)) {
+ return luaL_error(L, "Unable to read AEAD tag of encrypted data");
+ }
+
+ luaL_addsize(&ciphertext_buffer, ciphertext_len + 16);
+ luaL_pushresult(&ciphertext_buffer);
+
+ return 1;
+}
+
+static int Laes_128_gcm_encrypt(lua_State *L) {
+ return Laes_gcm_encrypt(L, EVP_aes_128_gcm(), 16);
+}
+
+static int Laes_256_gcm_encrypt(lua_State *L) {
+ return Laes_gcm_encrypt(L, EVP_aes_256_gcm(), 32);
+}
+
+/* gcm_decrypt(key, iv, ciphertext) */
+static int Laes_gcm_decrypt(lua_State *L, const EVP_CIPHER *cipher, const unsigned char expected_key_len) {
+ EVP_CIPHER_CTX *ctx;
+ luaL_Buffer plaintext_buffer;
+
+ size_t key_len, iv_len, ciphertext_len;
+ int plaintext_len, final_len;
+
+ const unsigned char *key = (unsigned char*)luaL_checklstring(L, 1, &key_len);
+ const unsigned char *iv = (unsigned char*)luaL_checklstring(L, 2, &iv_len);
+ const unsigned char *ciphertext = (unsigned char*)luaL_checklstring(L, 3, &ciphertext_len);
+
+ if(key_len != expected_key_len) {
+ return luaL_error(L, "key must be %d bytes", expected_key_len);
+ }
+ luaL_argcheck(L, iv_len == 12, 2, "iv must be 12 bytes");
+ luaL_argcheck(L, ciphertext_len > 16, 3, "ciphertext must be at least 16 bytes (including tag)");
+ if(lua_gettop(L) > 3) {
+ return luaL_error(L, "Expected 3 arguments, got %d", lua_gettop(L));
+ }
+
+ /* Create and initialise the context */
+ ctx = new_managed_EVP_CIPHER_CTX(L);
+
+ /* Initialise the decryption operation. */
+ if(!EVP_DecryptInit_ex(ctx, cipher, NULL, NULL, NULL)) {
+ return luaL_error(L, "Error while initializing decryption engine");
+ }
+
+ /* Initialise key and IV */
+ if(!EVP_DecryptInit_ex(ctx, NULL, NULL, key, iv)) {
+ return luaL_error(L, "Error while initializing key/iv");
+ }
+
+ luaL_buffinit(L, &plaintext_buffer);
+ unsigned char *plaintext = (unsigned char*)luaL_prepbuffsize(&plaintext_buffer, ciphertext_len);
+
+ /*
+ * Provide the message to be decrypted, and obtain the plaintext output.
+ * EVP_DecryptUpdate can be called multiple times if necessary
+ */
+ if(!EVP_DecryptUpdate(ctx, plaintext, &plaintext_len, ciphertext, ciphertext_len-16)) {
+ return luaL_error(L, "Error while decrypting data");
+ }
+
+ /* Set expected tag value. Works in OpenSSL 1.0.1d and later */
+ if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, 16, (unsigned char*)ciphertext + (ciphertext_len-16))) {
+ return luaL_error(L, "Error while processing authentication tag");
+ }
+
+ /*
+ * Finalise the decryption. A positive return value indicates success,
+ * anything else is a failure - the plaintext is not trustworthy.
+ */
+ int ret = EVP_DecryptFinal_ex(ctx, plaintext + plaintext_len, &final_len);
+
+ if(ret <= 0) {
+ /* Verify failed */
+ lua_pushnil(L);
+ lua_pushliteral(L, "verify-failed");
+ return 2;
+ }
+
+ luaL_addsize(&plaintext_buffer, plaintext_len + final_len);
+ luaL_pushresult(&plaintext_buffer);
+ return 1;
+}
+
+static int Laes_128_gcm_decrypt(lua_State *L) {
+ return Laes_gcm_decrypt(L, EVP_aes_128_gcm(), 16);
+}
+
+static int Laes_256_gcm_decrypt(lua_State *L) {
+ return Laes_gcm_decrypt(L, EVP_aes_256_gcm(), 32);
+}
+
+/* r, s = parse_ecdsa_sig(sig_der) */
+static int Lparse_ecdsa_signature(lua_State *L) {
+ ECDSA_SIG *sig;
+ size_t sig_der_len;
+ const unsigned char *sig_der = (unsigned char*)luaL_checklstring(L, 1, &sig_der_len);
+ const BIGNUM *r, *s;
+ luaL_Buffer rb, sb;
+ int rlen, slen;
+
+ sig = d2i_ECDSA_SIG(NULL, &sig_der, sig_der_len);
+
+ if(sig == NULL) {
+ lua_pushnil(L);
+ return 1;
+ }
+
+ ECDSA_SIG_get0(sig, &r, &s);
+
+ rlen = BN_num_bytes(r);
+ slen = BN_num_bytes(s);
+
+ // COMPAT w/ Lua 5.1
+ #if LUAL_BUFFERSIZE < 32
+ #error Configured LUAL_BUFFERSIZE is too small for this operation
+ #endif
+
+ luaL_buffinit(L, &rb);
+ BN_bn2bin(r, (unsigned char*)luaL_prepbuffer(&rb));
+ luaL_addsize(&rb, rlen);
+ luaL_pushresult(&rb);
+
+ luaL_buffinit(L, &sb);
+ BN_bn2bin(s, (unsigned char*)luaL_prepbuffer(&sb));
+ luaL_addsize(&sb, slen);
+ luaL_pushresult(&sb);
+
+ ECDSA_SIG_free(sig);
+
+ return 2;
+}
+
+/* sig_der = build_ecdsa_signature(r, s) */
+static int Lbuild_ecdsa_signature(lua_State *L) {
+ ECDSA_SIG *sig = ECDSA_SIG_new();
+ BIGNUM *r, *s;
+ luaL_Buffer sigbuf;
+
+ size_t rlen, slen;
+ const unsigned char *rbin, *sbin;
+
+ rbin = (unsigned char*)luaL_checklstring(L, 1, &rlen);
+ sbin = (unsigned char*)luaL_checklstring(L, 2, &slen);
+
+ r = BN_bin2bn(rbin, (int)rlen, NULL);
+ s = BN_bin2bn(sbin, (int)slen, NULL);
+
+ ECDSA_SIG_set0(sig, r, s);
+
+ luaL_buffinit(L, &sigbuf);
+
+ // COMPAT w/ Lua 5.1
+ #if LUAL_BUFFERSIZE < 128
+ #error Configured LUAL_BUFFERSIZE is too small for this operation
+ #endif
+
+ unsigned char *buffer = (unsigned char*)luaL_prepbuffer(&sigbuf);
+ int len = i2d_ECDSA_SIG(sig, &buffer);
+ luaL_addsize(&sigbuf, len);
+ luaL_pushresult(&sigbuf);
+
+ ECDSA_SIG_free(sig);
+
+ return 1;
+}
+
+static const luaL_Reg Reg[] = {
+ { "ed25519_sign", Led25519_sign },
+ { "ed25519_verify", Led25519_verify },
+ { "aes_128_gcm_encrypt", Laes_128_gcm_encrypt },
+ { "aes_128_gcm_decrypt", Laes_128_gcm_decrypt },
+ { "aes_256_gcm_encrypt", Laes_256_gcm_encrypt },
+ { "aes_256_gcm_decrypt", Laes_256_gcm_decrypt },
+ { "ecdsa_sha256_sign", Lecdsa_sha256_sign },
+ { "ecdsa_sha256_verify", Lecdsa_sha256_verify },
+ { "generate_ed25519_keypair", Lgenerate_ed25519_keypair },
+ { "import_private_pem", Limport_private_pem },
+ { "import_public_pem", Limport_public_pem },
+ { "parse_ecdsa_signature", Lparse_ecdsa_signature },
+ { "build_ecdsa_signature", Lbuild_ecdsa_signature },
+ { NULL, NULL }
+};
+
+static const luaL_Reg KeyMethods[] = {
+ { "private_pem", Lpkey_meth_private_pem },
+ { "public_pem", Lpkey_meth_public_pem },
+ { "get_type", Lpkey_meth_get_type },
+ { NULL, NULL }
+};
+
+static const luaL_Reg KeyMetatable[] = {
+ { "__gc", Lpkey_finalizer },
+ { NULL, NULL }
+};
+
+LUALIB_API int luaopen_util_crypto(lua_State *L) {
+#if (LUA_VERSION_NUM > 501)
+ luaL_checkversion(L);
+#endif
+
+ /* Initialize pkey metatable */
+ luaL_newmetatable(L, PKEY_MT_TAG);
+ luaL_setfuncs(L, KeyMetatable, 0);
+ lua_newtable(L);
+ luaL_setfuncs(L, KeyMethods, 0);
+ lua_setfield(L, -2, "__index");
+ lua_pop(L, 1);
+
+ /* Initialize lib table */
+ lua_newtable(L);
+ luaL_setfuncs(L, Reg, 0);
+ lua_pushliteral(L, "-3.14");
+ lua_setfield(L, -2, "version");
+#ifdef OPENSSL_VERSION
+ lua_pushstring(L, OpenSSL_version(OPENSSL_VERSION));
+ lua_setfield(L, -2, "_LIBCRYPTO_VERSION");
+#endif
+ return 1;
+}