1 files changed, 261 insertions, 0 deletions
diff --git a/user_channel/passwd_mgr.cpp b/user_channel/passwd_mgr.cpp
new file mode 100644
index 0000000..1d8a1ce
--- /dev/null
+++ b/user_channel/passwd_mgr.cpp
@@ -0,0 +1,261 @@
+/*
+// Copyright (c) 2018 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+*/
+
+#include "passwd_mgr.hpp"
+
+#include "shadowlock.hpp"
+
+#include <openssl/hmac.h>
+#include <openssl/sha.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include <cstring>
+#include <fstream>
+#include <phosphor-logging/log.hpp>
+
+namespace ipmi
+{
+
+static const char* passwdFileName = "/etc/ipmi_pass";
+static const char* encryptKeyFileName = "/etc/key_file";
+static const size_t maxKeySize = 8;
+
+static const char* META_PASSWD_SIG = "=OPENBMC=";
+
+/*
+ * Meta data struct for encrypted password file
+ */
+struct metaPassStruct
+{
+    char signature[10];
+    unsigned char reseved[2];
+    size_t hashSize;
+    size_t ivSize;
+    size_t dataSize;
+    size_t padSize;
+    size_t macSize;
+};
+
+using namespace phosphor::logging;
+
+PasswdMgr::PasswdMgr()
+{
+    initPasswordMap();
+}
+
+std::string PasswdMgr::getPasswdByUserName(const std::string& userName)
+{
+    checkAndReload();
+    auto iter = passwdMapList.find(userName);
+    if (iter == passwdMapList.end())
+    {
+        return std::string();
+    }
+    return iter->second;
+}
+
+void PasswdMgr::checkAndReload(void)
+{
+    struct stat fileStat = {};
+    if (stat(passwdFileName, &fileStat) != 0)
+    {
+        log<level::DEBUG>("Error in getting last updated time stamp");
+        return;
+    }
+    std::time_t updatedTime = fileStat.st_mtime;
+    if (fileLastUpdatedTime != updatedTime)
+    {
+        log<level::DEBUG>("Reloading password map list");
+        passwdMapList.clear();
+        initPasswordMap();
+    }
+}
+
+int PasswdMgr::decrypt(const EVP_CIPHER* cipher, uint8_t* key, size_t keyLen,
+                       uint8_t* iv, size_t ivLen, uint8_t* inBytes,
+                       size_t inBytesLen, uint8_t* mac, size_t macLen,
+                       uint8_t* outBytes, size_t* outBytesLen)
+{
+
+    if (cipher == NULL || key == NULL || iv == NULL || inBytes == NULL ||
+        outBytes == NULL || mac == NULL || inBytesLen == 0 ||
+        (size_t)EVP_CIPHER_key_length(cipher) > keyLen ||
+        (size_t)EVP_CIPHER_iv_length(cipher) > ivLen)
+    {
+        log<level::DEBUG>("Error Invalid Inputs");
+        return -1;
+    }
+
+    std::array<uint8_t, EVP_MAX_MD_SIZE> calMac;
+    size_t calMacLen = calMac.size();
+    // calculate MAC for the encrypted message.
+    if (NULL == HMAC(EVP_sha256(), key, keyLen, inBytes, inBytesLen,
+                     calMac.data(),
+                     reinterpret_cast<unsigned int*>(&calMacLen)))
+    {
+        log<level::DEBUG>("Error: Failed to calculate MAC");
+        return -1;
+    }
+    if (!((calMacLen == macLen) &&
+          (std::memcmp(calMac.data(), mac, calMacLen) == 0)))
+    {
+        log<level::DEBUG>("Authenticated message doesn't match");
+        return -1;
+    }
+
+    std::unique_ptr<EVP_CIPHER_CTX, decltype(&::EVP_CIPHER_CTX_free)> ctx(
+        EVP_CIPHER_CTX_new(), ::EVP_CIPHER_CTX_free);
+    EVP_CIPHER_CTX_set_padding(ctx.get(), 1);
+
+    // Set key & IV to decrypt
+    int retval = EVP_CipherInit_ex(ctx.get(), cipher, NULL, key, iv, 0);
+    if (!retval)
+    {
+        log<level::DEBUG>("EVP_CipherInit_ex failed",
+                          entry("RET_VAL=%d", retval));
+        return -1;
+    }
+
+    int outLen = 0, outEVPLen = 0;
+    if ((retval = EVP_CipherUpdate(ctx.get(), outBytes + outLen, &outEVPLen,
+                                   inBytes, inBytesLen)))
+    {
+        outLen += outEVPLen;
+        if ((retval =
+                 EVP_CipherFinal(ctx.get(), outBytes + outLen, &outEVPLen)))
+        {
+            outLen += outEVPLen;
+            *outBytesLen = outLen;
+        }
+        else
+        {
+            log<level::DEBUG>("EVP_CipherFinal fails",
+                              entry("RET_VAL=%d", retval));
+            return -1;
+        }
+    }
+    else
+    {
+        log<level::DEBUG>("EVP_CipherUpdate fails",
+                          entry("RET_VAL=%d", retval));
+        return -1;
+    }
+    return 0;
+}
+
+void PasswdMgr::initPasswordMap(void)
+{
+    phosphor::user::shadow::Lock lock();
+
+    std::array<uint8_t, maxKeySize> keyBuff;
+    std::ifstream keyFile(encryptKeyFileName, std::ios::in | std::ios::binary);
+    if (!keyFile.is_open())
+    {
+        log<level::DEBUG>("Error in opening encryption key file");
+        return;
+    }
+    keyFile.read((char*)keyBuff.data(), keyBuff.size());
+    if (keyFile.fail())
+    {
+        log<level::DEBUG>("Error in reading encryption key file");
+        return;
+    }
+
+    std::ifstream passwdFile(passwdFileName, std::ios::in | std::ios::binary);
+    if (!passwdFile.is_open())
+    {
+        log<level::DEBUG>("Error in opening ipmi password file");
+        return;
+    }
+
+    // calculate file size and read the data
+    std::vector<uint8_t> input;
+    passwdFile.seekg(0, std::ios::end);
+    ssize_t fileSize = passwdFile.tellg();
+    passwdFile.seekg(0, std::ios::beg);
+    input.resize(fileSize);
+    passwdFile.read((char*)input.data(), fileSize);
+    if (passwdFile.fail())
+    {
+        log<level::DEBUG>("Error in reading encryption key file");
+        return;
+    }
+
+    // verify the signature first
+    metaPassStruct* metaData = reinterpret_cast<metaPassStruct*>(input.data());
+    if (std::strncmp(metaData->signature, META_PASSWD_SIG,
+                     sizeof(metaData->signature)))
+    {
+        log<level::DEBUG>("Error signature mismatch in password file");
+        return;
+    }
+
+    // compute the key needed to decrypt
+    std::array<uint8_t, EVP_MAX_KEY_LENGTH> key;
+    auto keyLen = key.size();
+    HMAC(EVP_sha256(), keyBuff.data(), keyBuff.size(),
+         input.data() + sizeof(*metaData), metaData->hashSize, key.data(),
+         reinterpret_cast<unsigned int*>(&keyLen));
+
+    // decrypt the data
+    uint8_t* iv = input.data() + sizeof(*metaData) + metaData->hashSize;
+    size_t ivLen = metaData->ivSize;
+    uint8_t* inBytes = iv + ivLen;
+    size_t inBytesLen = metaData->dataSize + metaData->padSize;
+    uint8_t* mac = inBytes + inBytesLen;
+    size_t macLen = metaData->macSize;
+    std::vector<uint8_t> outBytes(inBytesLen + EVP_MAX_BLOCK_LENGTH);
+    size_t outBytesLen = outBytes.size();
+    if (decrypt(EVP_aes_128_cbc(), key.data(), keyLen, iv, ivLen, inBytes,
+                inBytesLen, mac, macLen, outBytes.data(), &outBytesLen) != 0)
+    {
+        log<level::DEBUG>("Error in decryption");
+        return;
+    }
+    outBytes[outBytesLen] = 0;
+    OPENSSL_cleanse(key.data(), keyLen);
+    OPENSSL_cleanse(iv, ivLen);
+
+    // populate the user list with password
+    char* outPtr = reinterpret_cast<char*>(outBytes.data());
+    char* nToken = NULL;
+    char* linePtr = strtok_r(outPtr, "\n", &nToken);
+    size_t userEPos = 0, lineSize = 0;
+    while (linePtr != NULL)
+    {
+        std::string lineStr(linePtr);
+        if ((userEPos = lineStr.find(":")) != std::string::npos)
+        {
+            lineSize = lineStr.size();
+            passwdMapList.emplace(
+                lineStr.substr(0, userEPos),
+                lineStr.substr(userEPos + 1, lineSize - (userEPos + 1)));
+        }
+        linePtr = strtok_r(NULL, "\n", &nToken);
+    }
+    // Update the timestamp
+    struct stat fileStat = {};
+    if (stat(passwdFileName, &fileStat) != 0)
+    {
+        log<level::DEBUG>("Error in getting last updated time stamp");
+        return;
+    }
+    fileLastUpdatedTime = fileStat.st_mtime;
+    return;
+}
+
+} // namespace ipmi