extensions/auth/nsAuthSambaNTLM.cpp
author Michael Comella <michael.l.comella@gmail.com>
Tue, 15 Sep 2015 16:46:58 -0700
changeset 266944 ed8188590f14b1aae2e4f44c8196994f375a99f4
parent 236973 e60e056a230c3792c8390f3e6808e97ad7cc3b47
child 297787 9a33547316416679c6901b963ac327ae8087a14b
permissions -rw-r--r--
Bug 1201206 - Correct menu button background on 2.3. r=mhaigh One fear is that different devices set different menu colors and text colors. Since we're using the default text color and set an explicit menu color, the text color may not look good on these devices. I was unable to find a way to override the menu text color. It seems the best way to find out if this is a problem is to land it and test though!

/* vim:set ts=4 sw=4 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsAuth.h"
#include "nsAuthSambaNTLM.h"
#include "prenv.h"
#include "plbase64.h"
#include "prerror.h"
#include "mozilla/Telemetry.h"

#include <stdlib.h>

nsAuthSambaNTLM::nsAuthSambaNTLM()
    : mInitialMessage(nullptr), mChildPID(nullptr), mFromChildFD(nullptr),
      mToChildFD(nullptr)
{
}

nsAuthSambaNTLM::~nsAuthSambaNTLM()
{
    // ntlm_auth reads from stdin regularly so closing our file handles
    // should cause it to exit.
    Shutdown();
    free(mInitialMessage);
}

void
nsAuthSambaNTLM::Shutdown()
{
    if (mFromChildFD) {
        PR_Close(mFromChildFD);
        mFromChildFD = nullptr;
    }
    if (mToChildFD) {
        PR_Close(mToChildFD);
        mToChildFD = nullptr;
    }
    if (mChildPID) {
        int32_t exitCode;
        PR_WaitProcess(mChildPID, &exitCode);
        mChildPID = nullptr;
    }
}

NS_IMPL_ISUPPORTS(nsAuthSambaNTLM, nsIAuthModule)

static bool
SpawnIOChild(char* const* aArgs, PRProcess** aPID,
             PRFileDesc** aFromChildFD, PRFileDesc** aToChildFD)
{
    PRFileDesc* toChildPipeRead;
    PRFileDesc* toChildPipeWrite;
    if (PR_CreatePipe(&toChildPipeRead, &toChildPipeWrite) != PR_SUCCESS)
        return false;
    PR_SetFDInheritable(toChildPipeRead, true);
    PR_SetFDInheritable(toChildPipeWrite, false);

    PRFileDesc* fromChildPipeRead;
    PRFileDesc* fromChildPipeWrite;
    if (PR_CreatePipe(&fromChildPipeRead, &fromChildPipeWrite) != PR_SUCCESS) {
        PR_Close(toChildPipeRead);
        PR_Close(toChildPipeWrite);
        return false;
    }
    PR_SetFDInheritable(fromChildPipeRead, false);
    PR_SetFDInheritable(fromChildPipeWrite, true);

    PRProcessAttr* attr = PR_NewProcessAttr();
    if (!attr) {
        PR_Close(fromChildPipeRead);
        PR_Close(fromChildPipeWrite);
        PR_Close(toChildPipeRead);
        PR_Close(toChildPipeWrite);
        return false;
    }

    PR_ProcessAttrSetStdioRedirect(attr, PR_StandardInput, toChildPipeRead);
    PR_ProcessAttrSetStdioRedirect(attr, PR_StandardOutput, fromChildPipeWrite);   

    PRProcess* process = PR_CreateProcess(aArgs[0], aArgs, nullptr, attr);
    PR_DestroyProcessAttr(attr);
    PR_Close(fromChildPipeWrite);
    PR_Close(toChildPipeRead);
    if (!process) {
        LOG(("ntlm_auth exec failure [%d]", PR_GetError()));
        PR_Close(fromChildPipeRead);
        PR_Close(toChildPipeWrite);
        return false;        
    }

    *aPID = process;
    *aFromChildFD = fromChildPipeRead;
    *aToChildFD = toChildPipeWrite;
    return true;
}

static bool WriteString(PRFileDesc* aFD, const nsACString& aString)
{
    int32_t length = aString.Length();
    const char* s = aString.BeginReading();
    LOG(("Writing to ntlm_auth: %s", s));

    while (length > 0) {
        int result = PR_Write(aFD, s, length);
        if (result <= 0)
            return false;
        s += result;
        length -= result;
    }
    return true;
}

static bool ReadLine(PRFileDesc* aFD, nsACString& aString)
{
    // ntlm_auth is defined to only send one line in response to each of our
    // input lines. So this simple unbuffered strategy works as long as we
    // read the response immediately after sending one request.
    aString.Truncate();
    for (;;) {
        char buf[1024];
        int result = PR_Read(aFD, buf, sizeof(buf));
        if (result <= 0)
            return false;
        aString.Append(buf, result);
        if (buf[result - 1] == '\n') {
            LOG(("Read from ntlm_auth: %s", nsPromiseFlatCString(aString).get()));
            return true;
        }
    }
}

/**
 * Returns a heap-allocated array of PRUint8s, and stores the length in aLen.
 * Returns nullptr if there's an error of any kind.
 */
static uint8_t* ExtractMessage(const nsACString& aLine, uint32_t* aLen)
{
    // ntlm_auth sends blobs to us as base64-encoded strings after the "xx "
    // preamble on the response line.
    int32_t length = aLine.Length();
    // The caller should verify there is a valid "xx " prefix and the line
    // is terminated with a \n
    NS_ASSERTION(length >= 4, "Line too short...");
    const char* line = aLine.BeginReading();
    const char* s = line + 3;
    length -= 4; // lose first 3 chars plus trailing \n
    NS_ASSERTION(s[length] == '\n', "aLine not newline-terminated");
    
    if (length & 3) {
        // The base64 encoded block must be multiple of 4. If not, something
        // screwed up.
        NS_WARNING("Base64 encoded block should be a multiple of 4 chars");
        return nullptr;
    } 

    // Calculate the exact length. I wonder why there isn't a function for this
    // in plbase64.
    int32_t numEquals;
    for (numEquals = 0; numEquals < length; ++numEquals) {
        if (s[length - 1 - numEquals] != '=')
            break;
    }
    *aLen = (length/4)*3 - numEquals;
    return reinterpret_cast<uint8_t*>(PL_Base64Decode(s, length, nullptr));
}

nsresult
nsAuthSambaNTLM::SpawnNTLMAuthHelper()
{
    const char* username = PR_GetEnv("USER");
    if (!username)
        return NS_ERROR_FAILURE;

    const char* const args[] = {
        "ntlm_auth",
        "--helper-protocol", "ntlmssp-client-1",
        "--use-cached-creds",
        "--username", username,
        nullptr
    };

    bool isOK = SpawnIOChild(const_cast<char* const*>(args), &mChildPID, &mFromChildFD, &mToChildFD);
    if (!isOK)  
        return NS_ERROR_FAILURE;

    if (!WriteString(mToChildFD, NS_LITERAL_CSTRING("YR\n")))
        return NS_ERROR_FAILURE;
    nsCString line;
    if (!ReadLine(mFromChildFD, line))
        return NS_ERROR_FAILURE;
    if (!StringBeginsWith(line, NS_LITERAL_CSTRING("YR "))) {
        // Something went wrong. Perhaps no credentials are accessible.
        return NS_ERROR_FAILURE;
    }

    // It gave us an initial client-to-server request packet. Save that
    // because we'll need it later.
    mInitialMessage = ExtractMessage(line, &mInitialMessageLen);
    if (!mInitialMessage)
        return NS_ERROR_FAILURE;
    return NS_OK;
}

NS_IMETHODIMP
nsAuthSambaNTLM::Init(const char *serviceName,
                      uint32_t    serviceFlags,
                      const char16_t *domain,
                      const char16_t *username,
                      const char16_t *password)
{
    NS_ASSERTION(!username && !domain && !password, "unexpected credentials");

    static bool sTelemetrySent = false;
    if (!sTelemetrySent) {
        mozilla::Telemetry::Accumulate(
            mozilla::Telemetry::NTLM_MODULE_USED_2,
            serviceFlags & nsIAuthModule::REQ_PROXY_AUTH
                ? NTLM_MODULE_SAMBA_AUTH_PROXY
                : NTLM_MODULE_SAMBA_AUTH_DIRECT);
        sTelemetrySent = true;
    }

    return NS_OK;
}

NS_IMETHODIMP
nsAuthSambaNTLM::GetNextToken(const void *inToken,
                              uint32_t    inTokenLen,
                              void      **outToken,
                              uint32_t   *outTokenLen)
{
    if (!inToken) {
        /* someone wants our initial message */
        *outToken = nsMemory::Clone(mInitialMessage, mInitialMessageLen);
        if (!*outToken)
            return NS_ERROR_OUT_OF_MEMORY;
        *outTokenLen = mInitialMessageLen;
        return NS_OK;
    }

    /* inToken must be a type 2 message. Get ntlm_auth to generate our response */
    char* encoded = PL_Base64Encode(static_cast<const char*>(inToken), inTokenLen, nullptr);
    if (!encoded)
        return NS_ERROR_OUT_OF_MEMORY;

    nsCString request;
    request.AssignLiteral("TT ");
    request.Append(encoded);
    free(encoded);
    request.Append('\n');

    if (!WriteString(mToChildFD, request))
        return NS_ERROR_FAILURE;
    nsCString line;
    if (!ReadLine(mFromChildFD, line))
        return NS_ERROR_FAILURE;
    if (!StringBeginsWith(line, NS_LITERAL_CSTRING("KK "))) {
        // Something went wrong. Perhaps no credentials are accessible.
        return NS_ERROR_FAILURE;
    }
    uint8_t* buf = ExtractMessage(line, outTokenLen);
    if (!buf)
        return NS_ERROR_FAILURE;
    *outToken = nsMemory::Clone(buf, *outTokenLen);
    free(buf);
    if (!*outToken) {
        return NS_ERROR_OUT_OF_MEMORY;
    }
    
    // We're done. Close our file descriptors now and reap the helper
    // process.
    Shutdown();
    return NS_SUCCESS_AUTH_FINISHED;
}

NS_IMETHODIMP
nsAuthSambaNTLM::Unwrap(const void *inToken,
                        uint32_t    inTokenLen,
                        void      **outToken,
                        uint32_t   *outTokenLen)
{
    return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
nsAuthSambaNTLM::Wrap(const void *inToken,
                      uint32_t    inTokenLen,
                      bool        confidential,
                      void      **outToken,
                      uint32_t   *outTokenLen)
{
    return NS_ERROR_NOT_IMPLEMENTED;
}