extensions/auth/nsAuthSambaNTLM.cpp
author Robert O'Callahan <robert@ocallahan.org>
Fri, 28 Sep 2012 23:19:39 +1200
changeset 108581 23f1b8c7d17e912c28c35987c3b321641bcb5c8d
parent 104982 c4f83d9d8243f3f853a5356188164a5fddee2b5a
permissions -rw-r--r--
Bug 539356. Make PruneDisplayListForExtraPage prune print preview properly. r=mattwoodrow PruneDisplayListForExtraPage wasn't pruning properly in print preview. It was pruning to the RootReferenceFrame, which is per-page when printing normally, but is the ancestor of all pages in print preview, so it wasn't doing anything in print preview. So, pass in the nsPageFrame we want to prune to. This prevents bogus entirely-clipped-out display items appearing in the display list for the page.

/* 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 <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_ISUPPORTS1(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 PRUnichar *domain,
                      const PRUnichar *username,
                      const PRUnichar *password)
{
    NS_ASSERTION(!username && !domain && !password, "unexpected credentials");
    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 has to be freed by nsMemory::Free, which may not be free() 
    *outToken = nsMemory::Clone(buf, *outTokenLen);
    if (!*outToken) {
        free(buf);
        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;
}

NS_IMETHODIMP
nsAuthSambaNTLM::GetModuleProperties(uint32_t *flags)
{
    *flags = 0;
    return NS_OK;
}