util.hashes, util.sasl.scram: Implement SCRAM-SHA1's Hi in C

diff --git a/util-src/hashes.c b/util-src/hashes.c
index 2a6625b3a6ddb9bae9a173fff6181bb35e882c1e..8f7d7140836f1ca030d08f33e728fefdc47bdb35 100644 (file)
--- a/util-src/hashes.c
+++ b/util-src/hashes.c
@@ -14,6 +14,8 @@
 */
 
 #include <string.h>
+#include <stdlib.h>
+#include <inttypes.h>
 
 #include "lua.h"
 #include "lauxlib.h"
@@ -132,6 +134,52 @@ MAKE_HMAC_FUNCTION(Lhmac_sha256, SHA256, SHA256_DIGEST_LENGTH, SHA256_CTX)
 MAKE_HMAC_FUNCTION(Lhmac_sha512, SHA512, SHA512_DIGEST_LENGTH, SHA512_CTX)
 MAKE_HMAC_FUNCTION(Lhmac_md5, MD5, MD5_DIGEST_LENGTH, MD5_CTX)
 
+static int LscramHi(lua_State *L) {
+       union xory {
+               unsigned char bytes[SHA_DIGEST_LENGTH];
+               uint32_t quadbytes[SHA_DIGEST_LENGTH/4];
+       };
+       int i;
+       SHA_CTX ctx, ctxo;
+       unsigned char Ust[SHA_DIGEST_LENGTH];
+       union xory Und;
+       union xory res;
+       size_t str_len, salt_len;
+       struct hash_desc desc;
+       const char *str = luaL_checklstring(L, 1, &str_len);
+       const char *salt = luaL_checklstring(L, 2, &salt_len);
+       char *salt2;
+       const int iter = luaL_checkinteger(L, 3);
+
+       desc.Init = (int (*)(void*))SHA1_Init;
+       desc.Update = (int (*)(void*, const void *, size_t))SHA1_Update;
+       desc.Final = (int (*)(unsigned char*, void*))SHA1_Final;
+       desc.digestLength = SHA_DIGEST_LENGTH;
+       desc.ctx = &ctx;
+       desc.ctxo = &ctxo;
+
+       salt2 = malloc(salt_len + 4);
+       if (salt2 == NULL)
+               luaL_error(L, "Out of memory in scramHi");
+       memcpy(salt2, salt, salt_len);
+       memcpy(salt2 + salt_len, "\0\0\0\1", 4);
+       hmac(&desc, str, str_len, salt2, salt_len + 4, Ust);
+       free(salt2);
+
+       memcpy(res.bytes, Ust, sizeof(res));
+       for (i = 1; i < iter; i++) {
+               int j;
+               hmac(&desc, str, str_len, (char*)Ust, sizeof(Ust), Und.bytes);
+               for (j = 0; j < SHA_DIGEST_LENGTH/4; j++)
+                       res.quadbytes[j] ^= Und.quadbytes[j];
+               memcpy(Ust, Und.bytes, sizeof(Ust));
+       }
+
+       lua_pushlstring(L, (char*)res.bytes, SHA_DIGEST_LENGTH);
+
+       return 1;
+}
+
 static const luaL_Reg Reg[] =
 {
        { "sha1",               Lsha1           },
@@ -144,6 +192,7 @@ static const luaL_Reg Reg[] =
        { "hmac_sha256",        Lhmac_sha256    },
        { "hmac_sha512",        Lhmac_sha512    },
        { "hmac_md5",           Lhmac_md5       },
+       { "scram_Hi_sha1",      LscramHi        },
        { NULL,                 NULL            }
 };
 

diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua
index 1ba1246055c6e35ffd3235fa41656eed725c823a..cf2f0ede940c3e8eb3696192487efe2b80848c9d 100644 (file)
--- a/util/sasl/scram.lua
+++ b/util/sasl/scram.lua
@@ -17,6 +17,7 @@ local string = string
 local base64 = require "util.encodings".base64;
 local hmac_sha1 = require "util.hashes".hmac_sha1;
 local sha1 = require "util.hashes".sha1;
+local Hi = require "util.hashes".scram_Hi_sha1;
 local generate_uuid = require "util.uuid".generate;
 local saslprep = require "util.encodings".stringprep.saslprep;
 local nodeprep = require "util.encodings".stringprep.nodeprep;
@@ -65,18 +66,6 @@ local function binaryXOR( a, b )
        return t_concat(result);
 end
 
--- hash algorithm independent Hi(PBKDF2) implementation
-function Hi(hmac, str, salt, i)
-       local Ust = hmac(str, salt.."\0\0\0\1");
-       local res = Ust;
-       for n=1,i-1 do
-               local Und = hmac(str, Ust)
-               res = binaryXOR(res, Und)
-               Ust = Und
-       end
-       return res
-end
-
 local function validate_username(username, _nodeprep)
        -- check for forbidden char sequences
        for eq in username:gmatch("=(.?.?)") do
@@ -110,7 +99,7 @@ function getAuthenticationDatabaseSHA1(password, salt, iteration_count)
        if iteration_count < 4096 then
                log("warn", "Iteration count < 4096 which is the suggested minimum according to RFC 5802.")
        end
-       local salted_password = Hi(hmac_sha1, password, salt, iteration_count);
+       local salted_password = Hi(password, salt, iteration_count);
        local stored_key = sha1(hmac_sha1(salted_password, "Client Key"))
        local server_key = hmac_sha1(salted_password, "Server Key");
        return true, stored_key, server_key