Add first user layer support.

Exposes user layer library which will be used by both
apphandler and netipmid for RAKP. Password is decrypted
from the special file which is used by pam-ipmi.

Change-Id: Ia6b99d4359a03843f19cd0e18f7269ad2e3cdb44
Signed-off-by: Richard Marian Thomaiyar <richard.marian.thomaiyar@linux.intel.com>

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