diff options
| -rw-r--r-- | src/lua/lua_cryptobox.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/src/lua/lua_cryptobox.c b/src/lua/lua_cryptobox.c index cda4912de..5f367ae04 100644 --- a/src/lua/lua_cryptobox.c +++ b/src/lua/lua_cryptobox.c @@ -26,11 +26,13 @@ * print(h:hex()) */ + #include "lua_common.h" #include "libcryptobox/cryptobox.h" #include "libcryptobox/keypair.h" #include "libcryptobox/keypair_private.h" #include "unix-std.h" +#include "contrib/libottery/ottery.h" struct rspamd_lua_cryptobox_hash { rspamd_cryptobox_hash_state_t *h; @@ -75,6 +77,8 @@ LUA_FUNCTION_DEF (cryptobox, encrypt_memory); LUA_FUNCTION_DEF (cryptobox, encrypt_file); LUA_FUNCTION_DEF (cryptobox, decrypt_memory); LUA_FUNCTION_DEF (cryptobox, decrypt_file); +LUA_FUNCTION_DEF (cryptobox, encrypt_cookie); +LUA_FUNCTION_DEF (cryptobox, decrypt_cookie); static const struct luaL_reg cryptoboxlib_f[] = { LUA_INTERFACE_DEF (cryptobox, verify_memory), @@ -85,6 +89,8 @@ static const struct luaL_reg cryptoboxlib_f[] = { LUA_INTERFACE_DEF (cryptobox, encrypt_file), LUA_INTERFACE_DEF (cryptobox, decrypt_memory), LUA_INTERFACE_DEF (cryptobox, decrypt_file), + LUA_INTERFACE_DEF (cryptobox, encrypt_cookie), + LUA_INTERFACE_DEF (cryptobox, decrypt_cookie), {NULL, NULL} }; @@ -1822,6 +1828,187 @@ lua_cryptobox_decrypt_file (lua_State *L) return 2; } +#define RSPAMD_CRYPTOBOX_AES_BLOCKSIZE 16 +#define RSPAMD_CRYPTOBOX_AES_KEYSIZE 16 + +/*** + * @function rspamd_cryptobox.encrypt_cookie(secret_key, secret_cookie) + * Specialised function that performs AES-CTR encryption of the provided cookie + * e := base64(nonce||aesencrypt(nonce, secret_cookie)) + * nonce := int64_le(unix_timestamp)||random_64bit + * aesencrypt := aes_ctr(nonce, secret_key) ^ pad(secret_cookie) + * pad := secret_cookie || 0^(32-len(secret_cookie)) + * @param {string} secret_key secret key as a hex string (must be 16 bytes in raw or 32 in hex) + * @param {string} secret_cookie secret cookie as a string for up to 31 character + * @return {string} e function value for this sk and cookie + */ +static gint +lua_cryptobox_encrypt_cookie (lua_State *L) +{ + guchar aes_block[RSPAMD_CRYPTOBOX_AES_BLOCKSIZE], *blk; + guchar padded_cookie[RSPAMD_CRYPTOBOX_AES_BLOCKSIZE]; + guchar nonce[RSPAMD_CRYPTOBOX_AES_BLOCKSIZE]; + guchar aes_key[RSPAMD_CRYPTOBOX_AES_KEYSIZE]; + guchar result[RSPAMD_CRYPTOBOX_AES_BLOCKSIZE * 2]; + guint64 ts; + + const gchar *sk, *cookie; + gsize sklen, cookie_len; + gint bklen; + + sk = lua_tolstring (L, 1, &sklen); + cookie = lua_tolstring (L, 2, &cookie_len); + + if (sk && cookie) { + if (sklen == 32) { + /* Hex */ + rspamd_decode_hex_buf (sk, sklen, aes_key, sizeof (aes_key)); + } + else if (sklen == RSPAMD_CRYPTOBOX_AES_KEYSIZE) { + /* Raw */ + memcpy (aes_key, sk, sizeof (aes_key)); + } + else { + return luaL_error (L, "invalid keysize %d", (gint)sklen); + } + + if (cookie_len > sizeof (padded_cookie) - 1) { + return luaL_error (L, "cookie is too long %d", (gint)padded_cookie); + } + + /* Fill nonce */ + ottery_rand_bytes (nonce, sizeof (nonce) / 2); + ts = (guint64)rspamd_get_calendar_ticks (); + memcpy (nonce + sizeof (nonce) / 2, &ts, sizeof (ts)); + + /* Prepare padded cookie */ + memset (padded_cookie, 0, sizeof (padded_cookie)); + memcpy (padded_cookie, cookie, cookie_len); + + /* Perform AES CTR via AES ECB on nonce */ + EVP_CIPHER_CTX *ctx; + ctx = EVP_CIPHER_CTX_new (); + EVP_EncryptInit_ex (ctx, EVP_aes_128_ecb (), NULL, aes_key, NULL); + EVP_CIPHER_CTX_set_padding (ctx, 0); + + bklen = sizeof (aes_block); + blk = aes_block; + g_assert (EVP_EncryptUpdate (ctx, blk, &bklen, nonce, sizeof (nonce))); + blk += bklen; + g_assert (EVP_EncryptFinal_ex(ctx, blk, &bklen)); + EVP_CIPHER_CTX_free (ctx); + + /* Encode result */ + memcpy (result, nonce, sizeof (nonce)); + for (guint i = 0; i < sizeof (aes_block); i ++) { + result[i + sizeof (nonce)] = padded_cookie[i] ^ aes_block[i]; + } + + gsize rlen; + gchar *res = rspamd_encode_base64 (result, sizeof (result), + 0, &rlen); + + lua_pushlstring (L, res, rlen); + g_free (res); + rspamd_explicit_memzero (aes_key, sizeof (aes_key)); + rspamd_explicit_memzero (aes_block, sizeof (aes_block)); + } + else { + return luaL_error (L, "invalid arguments"); + } + + return 1; +} + +/*** + * @function rspamd_cryptobox.decrypt_cookie(secret_key, encrypted_cookie) + * Specialised function that performs AES-CTR decryption of the provided cookie in form + * e := base64(nonce||aesencrypt(nonce, secret_cookie)) + * nonce := int64_le(unix_timestamp)||random_64bit + * aesencrypt := aes_ctr(nonce, secret_key) ^ pad(secret_cookie) + * pad := secret_cookie || 0^(32-len(secret_cookie)) + * @param {string} secret_key secret key as a hex string (must be 16 bytes in raw or 32 in hex) + * @param {string} encrypted_cookie encrypted cookie as a base64 encoded string + * @return {string} decrypted value of the cookie + */ +static gint +lua_cryptobox_decrypt_cookie (lua_State *L) +{ + guchar *blk; + guchar nonce[RSPAMD_CRYPTOBOX_AES_BLOCKSIZE]; + guchar aes_key[RSPAMD_CRYPTOBOX_AES_KEYSIZE]; + guchar *src; + guint64 ts; + + const gchar *sk, *cookie; + gsize sklen, cookie_len; + gint bklen; + + sk = lua_tolstring (L, 1, &sklen); + cookie = lua_tolstring (L, 2, &cookie_len); + + if (sk && cookie) { + if (sklen == 32) { + /* Hex */ + rspamd_decode_hex_buf (sk, sklen, aes_key, sizeof (aes_key)); + } + else if (sklen == RSPAMD_CRYPTOBOX_AES_KEYSIZE) { + /* Raw */ + memcpy (aes_key, sk, sizeof (aes_key)); + } + else { + return luaL_error (L, "invalid keysize %d", (gint)sklen); + } + + src = g_malloc (cookie_len); + + rspamd_cryptobox_base64_decode (cookie, cookie_len, src, &cookie_len); + + if (cookie_len != RSPAMD_CRYPTOBOX_AES_BLOCKSIZE * 2) { + g_free (src); + + return luaL_error (L, "invalid cookie len %d", (gint)cookie_len); + } + + /* Perform AES CTR via AES ECB on nonce */ + EVP_CIPHER_CTX *ctx; + ctx = EVP_CIPHER_CTX_new (); + /* As per CTR definition, we use encrypt for both encrypt and decrypt */ + EVP_EncryptInit_ex (ctx, EVP_aes_128_ecb (), NULL, aes_key, NULL); + EVP_CIPHER_CTX_set_padding (ctx, 0); + + bklen = sizeof (nonce); + blk = nonce; + g_assert (EVP_EncryptUpdate (ctx, blk, &bklen, src, + RSPAMD_CRYPTOBOX_AES_BLOCKSIZE)); + blk += bklen; + g_assert (EVP_EncryptFinal_ex (ctx, blk, &bklen)); + EVP_CIPHER_CTX_free (ctx); + + /* Decode result */ + for (guint i = 0; i < RSPAMD_CRYPTOBOX_AES_BLOCKSIZE; i ++) { + src[i + sizeof (nonce)] ^= nonce[i]; + } + + if (src[RSPAMD_CRYPTOBOX_AES_BLOCKSIZE * 2 - 1] != '\0') { + /* Bad cookie */ + lua_pushnil (L); + } + else { + lua_pushstring (L, src + sizeof (nonce)); + } + + rspamd_explicit_memzero (src, RSPAMD_CRYPTOBOX_AES_BLOCKSIZE * 2); + g_free (src); + rspamd_explicit_memzero (aes_key, sizeof (aes_key)); + } + else { + return luaL_error (L, "invalid arguments"); + } + + return 1; +} + static gint lua_load_pubkey (lua_State * L) { |