diff options
| -rw-r--r-- | spec/util_hashes_spec.lua | 38 | ||||
| -rw-r--r-- | util-src/hashes.c | 59 |
2 files changed, 97 insertions, 0 deletions
diff --git a/spec/util_hashes_spec.lua b/spec/util_hashes_spec.lua index b3b81467..f9f1633e 100644 --- a/spec/util_hashes_spec.lua +++ b/spec/util_hashes_spec.lua @@ -68,3 +68,41 @@ describe("SHA-3", function () end); end); +describe("HKDF", function () + describe("HMAC-SHA256", function () + describe("RFC 5869", function () + it("test vector A.1", function () + local ikm = hex.decode("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b"); + local salt = hex.decode("000102030405060708090a0b0c"); + local info = hex.decode("f0f1f2f3f4f5f6f7f8f9"); + + local expected = "3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865"; + + local ret = hashes.hkdf_hmac_sha256(42, ikm, salt, info); + assert.equal(expected, hex.encode(ret)); + end); + + it("test vector A.2", function () + local ikm = hex.decode("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f404142434445464748494a4b4c4d4e4f"); + local salt = hex.decode("606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9fa0a1a2a3a4a5a6a7a8a9aaabacadaeaf"); + local info = hex.decode("b0b1b2b3b4b5b6b7b8b9babbbcbdbebfc0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedfe0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff"); + + local expected = "b11e398dc80327a1c8e7f78c596a49344f012eda2d4efad8a050cc4c19afa97c59045a99cac7827271cb41c65e590e09da3275600c2f09b8367793a9aca3db71cc30c58179ec3e87c14c01d5c1f3434f1d87"; + + local ret = hashes.hkdf_hmac_sha256(82, ikm, salt, info); + assert.equal(expected, hex.encode(ret)); + end); + + it("test vector A.3", function () + local ikm = hex.decode("0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b"); + local salt = ""; + local info = ""; + + local expected = "8da4e775a563c18f715f802a063c5a31b8a11f5c5ee1879ec3454e5f3c738d2d9d201395faa4b61a96c8"; + + local ret = hashes.hkdf_hmac_sha256(42, ikm, salt, info); + assert.equal(expected, hex.encode(ret)); + end); + end); + end); +end); diff --git a/util-src/hashes.c b/util-src/hashes.c index 5d67ca63..d949193c 100644 --- a/util-src/hashes.c +++ b/util-src/hashes.c @@ -28,9 +28,17 @@ typedef unsigned __int32 uint32_t; #include <openssl/md5.h> #include <openssl/hmac.h> #include <openssl/evp.h> +#include <openssl/kdf.h> #include <openssl/err.h> +/* Semi-arbitrary limit here. The actual theoretical limit +* is (255*(hash output octets)), but allocating 16KB on the +* stack when in practice we only ever request a few dozen +* bytes seems excessive. +*/ +#define MAX_HKDF_OUTPUT 256 + static const char *hex_tab = "0123456789abcdef"; static void toHex(const unsigned char *in, int length, unsigned char *out) { int i; @@ -214,6 +222,55 @@ static int Lpbkdf2_sha256(lua_State *L) { return Levp_pbkdf2(L, EVP_sha256(), SHA256_DIGEST_LENGTH); } + +/* HKDF(length, input, salt, info) */ +static int Levp_hkdf(lua_State *L, const EVP_MD *evp) { + unsigned char out[MAX_HKDF_OUTPUT]; + + size_t input_len, salt_len, info_len; + size_t actual_out_len = luaL_checkinteger(L, 1); + const char *input = luaL_checklstring(L, 2, &input_len); + const unsigned char *salt = (unsigned char *)luaL_optlstring(L, 3, NULL, &salt_len); + const unsigned char *info = (unsigned char *)luaL_checklstring(L, 4, &info_len); + + if(actual_out_len > MAX_HKDF_OUTPUT) + return luaL_error(L, "desired output length %ul exceeds internal limit %ul", actual_out_len, MAX_HKDF_OUTPUT); + + EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); + + if (EVP_PKEY_derive_init(pctx) <= 0) + return luaL_error(L, ERR_error_string(ERR_get_error(), NULL)); + + if (EVP_PKEY_CTX_set_hkdf_md(pctx, evp) <= 0) + return luaL_error(L, ERR_error_string(ERR_get_error(), NULL)); + + if(salt != NULL) { + if (EVP_PKEY_CTX_set1_hkdf_salt(pctx, salt, salt_len) <= 0) + return luaL_error(L, ERR_error_string(ERR_get_error(), NULL)); + } + + if (EVP_PKEY_CTX_set1_hkdf_key(pctx, input, input_len) <= 0) + return luaL_error(L, ERR_error_string(ERR_get_error(), NULL)); + + if (EVP_PKEY_CTX_add1_hkdf_info(pctx, info, info_len) <= 0) + return luaL_error(L, ERR_error_string(ERR_get_error(), NULL)); + + if (EVP_PKEY_derive(pctx, out, &actual_out_len) <= 0) + return luaL_error(L, ERR_error_string(ERR_get_error(), NULL)); + + lua_pushlstring(L, (char *)out, actual_out_len); + + return 1; +} + +static int Lhkdf_sha256(lua_State *L) { + return Levp_hkdf(L, EVP_sha256()); +} + +static int Lhkdf_sha384(lua_State *L) { + return Levp_hkdf(L, EVP_sha384()); +} + static int Lhash_equals(lua_State *L) { size_t len1, len2; const char *s1 = luaL_checklstring(L, 1, &len1); @@ -250,6 +307,8 @@ static const luaL_Reg Reg[] = { { "scram_Hi_sha1", Lpbkdf2_sha1 }, /* COMPAT */ { "pbkdf2_hmac_sha1", Lpbkdf2_sha1 }, { "pbkdf2_hmac_sha256", Lpbkdf2_sha256 }, + { "hkdf_hmac_sha256", Lhkdf_sha256 }, + { "hkdf_hmac_sha384", Lhkdf_sha384 }, { "equals", Lhash_equals }, { NULL, NULL } }; |