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 /* 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/. */

 #ifdef XP_WIN

 #ifndef WIN32_LEAN_AND_MEAN

 #define WIN32_LEAN_AND_MEAN

 #endif

 #endif

 #include <sys/types.h>

 #include <sys/stat.h>

 #include <fcntl.h>

 #include <stdlib.h>

 #include <string.h>

 #include "mar_private.h"

 #include "mar_cmdline.h"

 #include "mar.h"

 #include "cryptox.h"

 #ifndef XP_WIN

 #include <unistd.h>

 #endif

 #include "nss_secutil.h"

 #include "base64.h"

 /**

  * Initializes the NSS context.

  * 

  * @param NSSConfigDir The config dir containing the private key to use

  * @return 0 on success

  *         -1 on error

 */

 int

 NSSInitCryptoContext(const char *NSSConfigDir)

 {

   SECStatus status = NSS_Initialize(NSSConfigDir, 

                                     "", "", SECMOD_DB, NSS_INIT_READONLY);

   if (SECSuccess != status) {

     fprintf(stderr, "ERROR: Could not initialize NSS\n");

     return -1;

   }

   return 0;

 }

 /** 

  * Obtains a signing context.

  *

  * @param  ctx A pointer to the signing context to fill

  * @return 0 on success

  *         -1 on error

 */

 int

 NSSSignBegin(const char *certName, 

              SGNContext **ctx, 

              SECKEYPrivateKey **privKey, 

              CERTCertificate **cert,

              uint32_t *signatureLength) 

 {

   secuPWData pwdata = { PW_NONE, 0 };

   if (!certName || !ctx || !privKey || !cert || !signatureLength) {

     fprintf(stderr, "ERROR: Invalid parameter passed to NSSSignBegin\n");

     return -1;

   }

   /* Get the cert and embedded public key out of the database */

   *cert = PK11_FindCertFromNickname(certName, &pwdata);

   if (!*cert) {

     fprintf(stderr, "ERROR: Could not find cert from nickname\n");

     return -1;

   }

   /* Get the private key out of the database */

   *privKey = PK11_FindKeyByAnyCert(*cert, &pwdata);

   if (!*privKey) {

     fprintf(stderr, "ERROR: Could not find private key\n");

     return -1;

   }

   *signatureLength = PK11_SignatureLen(*privKey);

   if (*signatureLength > BLOCKSIZE) {

     fprintf(stderr, 

             "ERROR: Program must be compiled with a larger block size"

             " to support signing with signatures this large: %u.\n", 

             *signatureLength);

     return -1;

   }

   /* Check that the key length is large enough for our requirements */

   if (*signatureLength < XP_MIN_SIGNATURE_LEN_IN_BYTES) {

     fprintf(stderr, "ERROR: Key length must be >= %d bytes\n", 

             XP_MIN_SIGNATURE_LEN_IN_BYTES);

     return -1;

   }

   *ctx = SGN_NewContext (SEC_OID_ISO_SHA1_WITH_RSA_SIGNATURE, *privKey);

   if (!*ctx) {

     fprintf(stderr, "ERROR: Could not create signature context\n");

     return -1;

   }

   if (SGN_Begin(*ctx) != SECSuccess) {

     fprintf(stderr, "ERROR: Could not begin signature\n");

     return -1;

   }

   return 0;

 }

 /**

  * Writes the passed buffer to the file fp and updates the signature contexts.

  *

  * @param  fpDest   The file pointer to write to.

  * @param  buffer   The buffer to write.

  * @param  size     The size of the buffer to write.

  * @param  ctxs     Pointer to the first element in an array of signature

  *                  contexts to update.

  * @param  ctxCount The number of signature contexts pointed to by ctxs

  * @param  err    The name of what is being written to in case of error.

  * @return  0 on success

  *         -2 on write error

  *         -3 on signature update error

 */

 int

 WriteAndUpdateSignatures(FILE *fpDest, void *buffer,

                          uint32_t size, SGNContext **ctxs,

                          uint32_t ctxCount,

                          const char *err)

 {

   uint32_t k;

   if (!size) { 

     return 0;

   }

   if (fwrite(buffer, size, 1, fpDest) != 1) {

     fprintf(stderr, "ERROR: Could not write %s\n", err);

     return -2;

   }

   for (k = 0; k < ctxCount; ++k) {

     if (SGN_Update(ctxs[k], buffer, size) != SECSuccess) {

       fprintf(stderr, "ERROR: Could not update signature context for %s\n", err);

       return -3;

     }

   }

   return 0;

 }

 /** 

  * Adjusts each entry's content offset in the the passed in index by the 

  * specified amount.

  *

  * @param indexBuf     A buffer containing the MAR index

  * @param indexLength  The length of the MAR index

  * @param offsetAmount The amount to adjust each index entry by

 */

 void

 AdjustIndexContentOffsets(char *indexBuf, uint32_t indexLength, uint32_t offsetAmount) 

 {

   uint32_t *offsetToContent;

   char *indexBufLoc = indexBuf;

   /* Consume the index and adjust each index by the specified amount */

   while (indexBufLoc != (indexBuf + indexLength)) {

     /* Adjust the offset */

     offsetToContent = (uint32_t *)indexBufLoc; 

     *offsetToContent = ntohl(*offsetToContent);

     *offsetToContent += offsetAmount;

     *offsetToContent = htonl(*offsetToContent);

     /* Skip past the offset, length, and flags */

     indexBufLoc += 3 * sizeof(uint32_t);

     indexBufLoc += strlen(indexBufLoc) + 1;

   }

 }

 /**

  * Reads from fpSrc, writes it to fpDest, and updates the signature contexts.

  *

  * @param  fpSrc    The file pointer to read from.

  * @param  fpDest   The file pointer to write to.

  * @param  buffer   The buffer to write.

  * @param  size     The size of the buffer to write.

  * @param  ctxs     Pointer to the first element in an array of signature

  *                  contexts to update.

  * @param  ctxCount The number of signature contexts pointed to by ctxs

  * @param  err    The name of what is being written to in case of error.

  * @return  0 on success

  *         -1 on read error

  *         -2 on write error

  *         -3 on signature update error

 */

 int

 ReadWriteAndUpdateSignatures(FILE *fpSrc, FILE *fpDest, void *buffer,

                              uint32_t size, SGNContext **ctxs,

                              uint32_t ctxCount,

                              const char *err)

 {

   if (!size) { 

     return 0;

   }

   if (fread(buffer, size, 1, fpSrc) != 1) {

     fprintf(stderr, "ERROR: Could not read %s\n", err);

     return -1;

   }

   return WriteAndUpdateSignatures(fpDest, buffer, size, ctxs, ctxCount, err);

 }

 /**

  * Reads from fpSrc, writes it to fpDest.

  *

  * @param  fpSrc  The file pointer to read from.

  * @param  fpDest The file pointer to write to.

  * @param  buffer The buffer to write.

  * @param  size   The size of the buffer to write.

  * @param  err    The name of what is being written to in case of error.

  * @return  0 on success

  *         -1 on read error

  *         -2 on write error

 */

 int

 ReadAndWrite(FILE *fpSrc, FILE *fpDest, void *buffer, 

              uint32_t size, const char *err) 

 {

   if (!size) { 

     return 0;

   }

   if (fread(buffer, size, 1, fpSrc) != 1) {

     fprintf(stderr, "ERROR: Could not read %s\n", err);

     return -1;

   }

   if (fwrite(buffer, size, 1, fpDest) != 1) {

     fprintf(stderr, "ERROR: Could not write %s\n", err);

     return -2;

   }

   return 0;

 }

 /**

  * Writes out a copy of the MAR at src but with the signature block stripped.

  *

  * @param  src  The path of the source MAR file

  * @param  dest The path of the MAR file to write out that 

                 has no signature block

  * @return 0 on success

  *         -1 on error

 */

 int

 strip_signature_block(const char *src, const char * dest)

 {

   uint32_t offsetToIndex, dstOffsetToIndex, indexLength, 

     numSignatures = 0, leftOver;

   int32_t stripAmount = 0;

   int64_t oldPos, sizeOfEntireMAR = 0, realSizeOfSrcMAR, numBytesToCopy,

     numChunks, i;

   FILE *fpSrc = NULL, *fpDest = NULL;

   int rv = -1, hasSignatureBlock;

   char buf[BLOCKSIZE];

   char *indexBuf = NULL, *indexBufLoc;

   if (!src || !dest) {

     fprintf(stderr, "ERROR: Invalid parameter passed in.\n");

     return -1;

   }

   fpSrc = fopen(src, "rb");

   if (!fpSrc) {

     fprintf(stderr, "ERROR: could not open source file: %s\n", src);

     goto failure;

   }

   fpDest = fopen(dest, "wb");

   if (!fpDest) {

     fprintf(stderr, "ERROR: could not create target file: %s\n", dest);

     goto failure;

   }

   /* Determine if the source MAR file has the new fields for signing or not */

   if (get_mar_file_info(src, &hasSignatureBlock, NULL, NULL, NULL, NULL)) {

     fprintf(stderr, "ERROR: could not determine if MAR is old or new.\n");

     goto failure;

   }

   /* MAR ID */

   if (ReadAndWrite(fpSrc, fpDest, buf, MAR_ID_SIZE, "MAR ID")) {

     goto failure;

   }

   /* Offset to index */

   if (fread(&offsetToIndex, sizeof(offsetToIndex), 1, fpSrc) != 1) {

     fprintf(stderr, "ERROR: Could not read offset\n");

     goto failure;

   }

   offsetToIndex = ntohl(offsetToIndex);

   /* Get the real size of the MAR */

   oldPos = ftello(fpSrc);

   if (fseeko(fpSrc, 0, SEEK_END)) {

     fprintf(stderr, "ERROR: Could not seek to end of file.\n");

     goto failure;

   }

   realSizeOfSrcMAR = ftello(fpSrc);

   if (fseeko(fpSrc, oldPos, SEEK_SET)) {

     fprintf(stderr, "ERROR: Could not seek back to current location.\n");

     goto failure;

   }

   if (hasSignatureBlock) {

     /* Get the MAR length and adjust its size */

     if (fread(&sizeOfEntireMAR, 

               sizeof(sizeOfEntireMAR), 1, fpSrc) != 1) {

       fprintf(stderr, "ERROR: Could read mar size\n");

       goto failure;

     }

     sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);

     if (sizeOfEntireMAR != realSizeOfSrcMAR) {

       fprintf(stderr, "ERROR: Source MAR is not of the right size\n");

       goto failure;

     }

     /* Get the num signatures in the source file so we know what to strip */

     if (fread(&numSignatures, sizeof(numSignatures), 1, fpSrc) != 1) {

       fprintf(stderr, "ERROR: Could read num signatures\n");

       goto failure;

     }

     numSignatures = ntohl(numSignatures);

     for (i = 0; i < numSignatures; i++) {

       uint32_t signatureLen;

       /* Skip past the signature algorithm ID */

       if (fseeko(fpSrc, sizeof(uint32_t), SEEK_CUR)) {

         fprintf(stderr, "ERROR: Could not skip past signature algorithm ID\n");

       }

       /* Read in the length of the signature so we know how far to skip */

       if (fread(&signatureLen, sizeof(uint32_t), 1, fpSrc) != 1) {

         fprintf(stderr, "ERROR: Could not read signatures length.\n");

         return CryptoX_Error;

       }

       signatureLen = ntohl(signatureLen);

       /* Skip past the signature */

       if (fseeko(fpSrc, signatureLen, SEEK_CUR)) {

         fprintf(stderr, "ERROR: Could not skip past signature algorithm ID\n");

       }

       stripAmount += sizeof(uint32_t) + sizeof(uint32_t) + signatureLen; 

     }

   } else {

     sizeOfEntireMAR = realSizeOfSrcMAR;

     numSignatures = 0;

   }

   if (((int64_t)offsetToIndex) > sizeOfEntireMAR) {

     fprintf(stderr, "ERROR: Offset to index is larger than the file size.\n");

     goto failure;

   }

   dstOffsetToIndex = offsetToIndex;

   if (!hasSignatureBlock) {

     dstOffsetToIndex += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);

   }

   dstOffsetToIndex -= stripAmount;

   /* Write out the index offset */

   dstOffsetToIndex = htonl(dstOffsetToIndex);

   if (fwrite(&dstOffsetToIndex, sizeof(dstOffsetToIndex), 1, fpDest) != 1) {

     fprintf(stderr, "ERROR: Could not write offset to index\n");

     goto failure;

   }

   dstOffsetToIndex = ntohl(dstOffsetToIndex);

   /* Write out the new MAR file size */

   if (!hasSignatureBlock) {

     sizeOfEntireMAR += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);

   }

   sizeOfEntireMAR -= stripAmount;

   /* Write out the MAR size */

   sizeOfEntireMAR = HOST_TO_NETWORK64(sizeOfEntireMAR);

   if (fwrite(&sizeOfEntireMAR, sizeof(sizeOfEntireMAR), 1, fpDest) != 1) {

     fprintf(stderr, "ERROR: Could not write size of MAR\n");

     goto failure;

   }

   sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);

   /* Write out the number of signatures, which is 0 */

   numSignatures = 0;

   if (fwrite(&numSignatures, sizeof(numSignatures), 1, fpDest) != 1) {

     fprintf(stderr, "ERROR: Could not write out num signatures\n");

     goto failure;

   }

   /* Write out the rest of the MAR excluding the index header and index

      offsetToIndex unfortunately has to remain 32-bit because for backwards

      compatibility with the old MAR file format. */

   if (ftello(fpSrc) > ((int64_t)offsetToIndex)) {

     fprintf(stderr, "ERROR: Index offset is too small.\n");

     goto failure;

   }

   numBytesToCopy = ((int64_t)offsetToIndex) - ftello(fpSrc);

   numChunks = numBytesToCopy / BLOCKSIZE;

   leftOver = numBytesToCopy % BLOCKSIZE;

   /* Read each file and write it to the MAR file */

   for (i = 0; i < numChunks; ++i) {

     if (ReadAndWrite(fpSrc, fpDest, buf, BLOCKSIZE, "content block")) {

       goto failure;

     }

   }

   /* Write out the left over */

   if (ReadAndWrite(fpSrc, fpDest, buf, 

                    leftOver, "left over content block")) {

     goto failure;

   }

   /* Length of the index */

   if (ReadAndWrite(fpSrc, fpDest, &indexLength, 

                    sizeof(indexLength), "index length")) {

     goto failure;

   }

   indexLength = ntohl(indexLength);

   /* Consume the index and adjust each index by the difference */

   indexBuf = malloc(indexLength);

   indexBufLoc = indexBuf;

   if (fread(indexBuf, indexLength, 1, fpSrc) != 1) {

     fprintf(stderr, "ERROR: Could not read index\n");

     goto failure;

   }

   /* Adjust each entry in the index */

   if (hasSignatureBlock) {

     AdjustIndexContentOffsets(indexBuf, indexLength, -stripAmount);

   } else {

     AdjustIndexContentOffsets(indexBuf, indexLength, 

                               sizeof(sizeOfEntireMAR) + 

                               sizeof(numSignatures) - 

                               stripAmount);

   }

   if (fwrite(indexBuf, indexLength, 1, fpDest) != 1) {

     fprintf(stderr, "ERROR: Could not write index\n");

     goto failure;

   }

   rv = 0;

 failure: 

   if (fpSrc) {

     fclose(fpSrc);

   }

   if (fpDest) {

     fclose(fpDest);

   }

   if (rv) {

     remove(dest);

   }

   if (indexBuf) { 

     free(indexBuf);

   }

   if (rv) {

     remove(dest);

   }

   return rv;

 }

 /**

  * Extracts a signature from a MAR file, base64 encodes it, and writes it out

  *

  * @param  src       The path of the source MAR file

  * @param  sigIndex  The index of the signature to extract

  * @param  dest      The path of file to write the signature to

  * @return 0 on success

  *         -1 on error

 */

 int

 extract_signature(const char *src, uint32_t sigIndex, const char * dest)

 {

   FILE *fpSrc = NULL, *fpDest = NULL;

   uint32_t i;

   uint32_t signatureCount;

   uint32_t signatureLen;

   uint8_t *extractedSignature = NULL;

   char *base64Encoded = NULL;

   int rv = -1;

   if (!src || !dest) {

     fprintf(stderr, "ERROR: Invalid parameter passed in.\n");

     goto failure;

   }

   fpSrc = fopen(src, "rb");

   if (!fpSrc) {

     fprintf(stderr, "ERROR: could not open source file: %s\n", src);

     goto failure;

   }

   fpDest = fopen(dest, "wb");

   if (!fpDest) {

     fprintf(stderr, "ERROR: could not create target file: %s\n", dest);

     goto failure;

   }

   /* Skip to the start of the signature block */

   if (fseeko(fpSrc, SIGNATURE_BLOCK_OFFSET, SEEK_SET)) {

     fprintf(stderr, "ERROR: could not seek to signature block\n");

     goto failure;

   }

   /* Get the number of signatures */

   if (fread(&signatureCount, sizeof(signatureCount), 1, fpSrc) != 1) {

     fprintf(stderr, "ERROR: could not read signature count\n");

     goto failure;

   }

   signatureCount = ntohl(signatureCount);

   if (sigIndex >= signatureCount) {

     fprintf(stderr, "ERROR: Signature index was out of range\n");

     goto failure;

   }

   /* Skip to the correct signature */

   for (i = 0; i <= sigIndex; i++) {

     /* skip past the signature algorithm ID */

     if (fseeko(fpSrc, sizeof(uint32_t), SEEK_CUR)) {

       fprintf(stderr, "ERROR: Could not seek past sig algorithm ID.\n");

       goto failure;

     }

     /* Get the signature length */

     if (fread(&signatureLen, sizeof(signatureLen), 1, fpSrc) != 1) {

       fprintf(stderr, "ERROR: could not read signature length\n");

       goto failure;

     }

     signatureLen = ntohl(signatureLen);

     /* Get the signature */

     extractedSignature = malloc(signatureLen);

     if (fread(extractedSignature, signatureLen, 1, fpSrc) != 1) {

       fprintf(stderr, "ERROR: could not read signature\n");

       goto failure;

     }

   }

   base64Encoded = BTOA_DataToAscii(extractedSignature, signatureLen);

   if (!base64Encoded) {

     fprintf(stderr, "ERROR: could not obtain base64 encoded data\n");

     goto failure;

   }

   if (fwrite(base64Encoded, strlen(base64Encoded), 1, fpDest) != 1) {

     fprintf(stderr, "ERROR: Could not write base64 encoded string\n");

     goto failure;

   }

   rv = 0;

 failure:

   if (base64Encoded) {

     PORT_Free(base64Encoded);

   }

   if (extractedSignature) {

     free(extractedSignature);

   }

   if (fpSrc) {

     fclose(fpSrc);

   }

   if (fpDest) {

     fclose(fpDest);

   }

   if (rv) {

     remove(dest);

   }

   return rv;

 }

 /**

  * Imports a base64 encoded signature into a MAR file

  *

  * @param  src           The path of the source MAR file

  * @param  sigIndex      The index of the signature to import

  * @param  base64SigFile A file which contains the signature to import

  * @param  dest          The path of the destination MAR file with replaced signature

  * @return 0 on success

  *         -1 on error

 */

 int

 import_signature(const char *src, uint32_t sigIndex,

                  const char *base64SigFile, const char *dest)

 {

   int rv = -1;

   FILE *fpSrc = NULL;

   FILE *fpDest = NULL;

   FILE *fpSigFile = NULL;

   uint32_t i;

   uint32_t signatureCount, signatureLen, signatureAlgorithmID,

            numChunks, leftOver;

   char buf[BLOCKSIZE];

   uint64_t sizeOfSrcMAR, sizeOfBase64EncodedFile;

   char *passedInSignatureB64 = NULL;

   uint8_t *passedInSignatureRaw = NULL;

   uint8_t *extractedMARSignature = NULL;

   unsigned int passedInSignatureLenRaw;

   if (!src || !dest) {

     fprintf(stderr, "ERROR: Invalid parameter passed in.\n");

     goto failure;

   }

   fpSrc = fopen(src, "rb");

   if (!fpSrc) {

     fprintf(stderr, "ERROR: could not open source file: %s\n", src);

     goto failure;

   }

   fpDest = fopen(dest, "wb");

   if (!fpDest) {

     fprintf(stderr, "ERROR: could not open dest file: %s\n", dest);

     goto failure;

   }

   fpSigFile = fopen(base64SigFile , "rb");

   if (!fpSigFile) {

     fprintf(stderr, "ERROR: could not open sig file: %s\n", base64SigFile);

     goto failure;

   }

   /* Get the src file size */

   if (fseeko(fpSrc, 0, SEEK_END)) {

     fprintf(stderr, "ERROR: Could not seek to end of src file.\n");

     goto failure;

   }

   sizeOfSrcMAR = ftello(fpSrc);

   if (fseeko(fpSrc, 0, SEEK_SET)) {

     fprintf(stderr, "ERROR: Could not seek to start of src file.\n");

     goto failure;

   }

   /* Get the sig file size */

   if (fseeko(fpSigFile, 0, SEEK_END)) {

     fprintf(stderr, "ERROR: Could not seek to end of sig file.\n");

     goto failure;

   }

   sizeOfBase64EncodedFile= ftello(fpSigFile);

   if (fseeko(fpSigFile, 0, SEEK_SET)) {

     fprintf(stderr, "ERROR: Could not seek to start of sig file.\n");

     goto failure;

   }

   /* Read in the base64 encoded signature to import */

   passedInSignatureB64 = malloc(sizeOfBase64EncodedFile + 1);

   passedInSignatureB64[sizeOfBase64EncodedFile] = '\0';

   if (fread(passedInSignatureB64, sizeOfBase64EncodedFile, 1, fpSigFile) != 1) {

     fprintf(stderr, "ERROR: Could read b64 sig file.\n");

     goto failure;

   }

   /* Decode the base64 encoded data */

   passedInSignatureRaw = ATOB_AsciiToData(passedInSignatureB64, &passedInSignatureLenRaw);

   if (!passedInSignatureRaw) {

     fprintf(stderr, "ERROR: could not obtain base64 decoded data\n");

     goto failure;

   }

   /* Read everything up until the signature block offset and write it out */

   if (ReadAndWrite(fpSrc, fpDest, buf,

                    SIGNATURE_BLOCK_OFFSET, "signature block offset")) {

     goto failure;

   }

   /* Get the number of signatures */

   if (ReadAndWrite(fpSrc, fpDest, &signatureCount,

                    sizeof(signatureCount), "signature count")) {

     goto failure;

   }

   signatureCount = ntohl(signatureCount);

   if (signatureCount > MAX_SIGNATURES) {

     fprintf(stderr, "ERROR: Signature count was out of range\n");

     goto failure;

   }

   if (sigIndex >= signatureCount) {

     fprintf(stderr, "ERROR: Signature index was out of range\n");

     goto failure;

   }

   /* Read and write the whole signature block, but if we reach the

      signature offset, then we should replace it with the specified

      base64 decoded signature */

   for (i = 0; i < signatureCount; i++) {

     /* Read/Write the signature algorithm ID */

     if (ReadAndWrite(fpSrc, fpDest,

                      &signatureAlgorithmID,

                      sizeof(signatureAlgorithmID), "sig algorithm ID")) {

       goto failure;

     }

     /* Read/Write the signature length */

     if (ReadAndWrite(fpSrc, fpDest,

                      &signatureLen, sizeof(signatureLen), "sig length")) {

       goto failure;

     }

     signatureLen = ntohl(signatureLen);

     /* Get the signature */

     if (extractedMARSignature) {

       free(extractedMARSignature);

     }

     extractedMARSignature = malloc(signatureLen);

     if (sigIndex == i) {

       if (passedInSignatureLenRaw != signatureLen) {

         fprintf(stderr, "ERROR: Signature length must be the same\n");

         goto failure;

       }

       if (fread(extractedMARSignature, signatureLen, 1, fpSrc) != 1) {

         fprintf(stderr, "ERROR: Could not read signature\n");

         goto failure;

       }

       if (fwrite(passedInSignatureRaw, passedInSignatureLenRaw,

                  1, fpDest) != 1) {

         fprintf(stderr, "ERROR: Could not write signature\n");

         goto failure;

       }

     } else {

       if (ReadAndWrite(fpSrc, fpDest,

                        extractedMARSignature, signatureLen, "signature")) {

         goto failure;

       }

     }

   }

   /* We replaced the signature so let's just skip past the rest o the

      file. */

   numChunks = (sizeOfSrcMAR - ftello(fpSrc)) / BLOCKSIZE;

   leftOver = (sizeOfSrcMAR - ftello(fpSrc)) % BLOCKSIZE;

   /* Read each file and write it to the MAR file */

   for (i = 0; i < numChunks; ++i) {

     if (ReadAndWrite(fpSrc, fpDest, buf, BLOCKSIZE, "content block")) {

       goto failure;

     }

   }

   if (ReadAndWrite(fpSrc, fpDest, buf, leftOver, "left over content block")) {

     goto failure;

   }

   rv = 0;

 failure:

   if (fpSrc) {

     fclose(fpSrc);

   }

   if (fpDest) {

     fclose(fpDest);

   }

   if (fpSigFile) {

     fclose(fpSigFile);

   }

   if (rv) {

     remove(dest);

   }

   if (extractedMARSignature) {

     free(extractedMARSignature);

   }

   if (passedInSignatureB64) {

     free(passedInSignatureB64);

   }

   if (passedInSignatureRaw) {

     PORT_Free(passedInSignatureRaw);

   }

   return rv;

 }

 /**

  * Writes out a copy of the MAR at src but with embedded signatures.

  * The passed in MAR file must not already be signed or an error will 

  * be returned.

  *

  * @param  NSSConfigDir  The NSS directory containing the private key for signing

  * @param  certNames     The nicknames of the certificate to use for signing

  * @param  certCount     The number of certificate names contained in certNames.

  *                       One signature will be produced for each certificate.

  * @param  src           The path of the source MAR file to sign

  * @param  dest          The path of the MAR file to write out that is signed

  * @return 0 on success

  *         -1 on error

 */

 int

 mar_repackage_and_sign(const char *NSSConfigDir, 

                        const char * const *certNames,

                        uint32_t certCount,

                        const char *src, 

                        const char *dest) 

 {

   uint32_t offsetToIndex, dstOffsetToIndex, indexLength, 

     numSignatures = 0, leftOver,

     signatureAlgorithmID, signatureSectionLength = 0;

   uint32_t signatureLengths[MAX_SIGNATURES];

   int64_t oldPos, sizeOfEntireMAR = 0, realSizeOfSrcMAR, 

     signaturePlaceholderOffset, numBytesToCopy, 

     numChunks, i;

   FILE *fpSrc = NULL, *fpDest = NULL;

   int rv = -1, hasSignatureBlock;

   SGNContext *ctxs[MAX_SIGNATURES];

   SECItem secItems[MAX_SIGNATURES];

   char buf[BLOCKSIZE];

   SECKEYPrivateKey *privKeys[MAX_SIGNATURES];

   CERTCertificate *certs[MAX_SIGNATURES];

   char *indexBuf = NULL, *indexBufLoc;

   uint32_t k;

   memset(signatureLengths, 0, sizeof(signatureLengths));

   memset(ctxs, 0, sizeof(ctxs));

   memset(secItems, 0, sizeof(secItems));

   memset(privKeys, 0, sizeof(privKeys));

   memset(certs, 0, sizeof(certs));

   if (!NSSConfigDir || !certNames || certCount == 0 || !src || !dest) {

     fprintf(stderr, "ERROR: Invalid parameter passed in.\n");

     return -1;

   }

   if (NSSInitCryptoContext(NSSConfigDir)) {

     fprintf(stderr, "ERROR: Could not init config dir: %s\n", NSSConfigDir);

     goto failure;

   }

   PK11_SetPasswordFunc(SECU_GetModulePassword);

   fpSrc = fopen(src, "rb");

   if (!fpSrc) {

     fprintf(stderr, "ERROR: could not open source file: %s\n", src);

     goto failure;

   }

   fpDest = fopen(dest, "wb");

   if (!fpDest) {

     fprintf(stderr, "ERROR: could not create target file: %s\n", dest);

     goto failure;

   }

   /* Determine if the source MAR file has the new fields for signing or not */

   if (get_mar_file_info(src, &hasSignatureBlock, NULL, NULL, NULL, NULL)) {

     fprintf(stderr, "ERROR: could not determine if MAR is old or new.\n");

     goto failure;

   }

   for (k = 0; k < certCount; k++) {

     if (NSSSignBegin(certNames[k], &ctxs[k], &privKeys[k],

                      &certs[k], &signatureLengths[k])) {

       fprintf(stderr, "ERROR: NSSSignBegin failed\n");

       goto failure;

     }

   }

   /* MAR ID */

   if (ReadWriteAndUpdateSignatures(fpSrc, fpDest,

                                    buf, MAR_ID_SIZE,

                                    ctxs, certCount, "MAR ID")) {

     goto failure;

   }

   /* Offset to index */

   if (fread(&offsetToIndex, sizeof(offsetToIndex), 1, fpSrc) != 1) {

     fprintf(stderr, "ERROR: Could not read offset\n");

     goto failure;

   }

   offsetToIndex = ntohl(offsetToIndex);

   /* Get the real size of the MAR */

   oldPos = ftello(fpSrc);

   if (fseeko(fpSrc, 0, SEEK_END)) {

     fprintf(stderr, "ERROR: Could not seek to end of file.\n");

     goto failure;

   }

   realSizeOfSrcMAR = ftello(fpSrc);

   if (fseeko(fpSrc, oldPos, SEEK_SET)) {

     fprintf(stderr, "ERROR: Could not seek back to current location.\n");

     goto failure;

   }

   if (hasSignatureBlock) {

     /* Get the MAR length and adjust its size */

     if (fread(&sizeOfEntireMAR, 

               sizeof(sizeOfEntireMAR), 1, fpSrc) != 1) {

       fprintf(stderr, "ERROR: Could read mar size\n");

       goto failure;

     }

     sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);

     if (sizeOfEntireMAR != realSizeOfSrcMAR) {

       fprintf(stderr, "ERROR: Source MAR is not of the right size\n");

       goto failure;

     }

     /* Get the num signatures in the source file */

     if (fread(&numSignatures, sizeof(numSignatures), 1, fpSrc) != 1) {

       fprintf(stderr, "ERROR: Could read num signatures\n");

       goto failure;

     }

     numSignatures = ntohl(numSignatures);

     /* We do not support resigning, if you have multiple signatures,

        you must add them all at the same time. */

     if (numSignatures) {

       fprintf(stderr, "ERROR: MAR is already signed\n");

       goto failure;

     }

   } else {

     sizeOfEntireMAR = realSizeOfSrcMAR;

   }

   if (((int64_t)offsetToIndex) > sizeOfEntireMAR) {

     fprintf(stderr, "ERROR: Offset to index is larger than the file size.\n");

     goto failure;

   }

   /* Calculate the total signature block length */

   for (k = 0; k < certCount; k++) {

     signatureSectionLength += sizeof(signatureAlgorithmID) +

                               sizeof(signatureLengths[k]) +

                               signatureLengths[k];

   }

   dstOffsetToIndex = offsetToIndex;

   if (!hasSignatureBlock) {

     dstOffsetToIndex += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);

   }

   dstOffsetToIndex += signatureSectionLength;

   /* Write out the index offset */

   dstOffsetToIndex = htonl(dstOffsetToIndex);

   if (WriteAndUpdateSignatures(fpDest, &dstOffsetToIndex,

                                sizeof(dstOffsetToIndex), ctxs, certCount,

                                "index offset")) {

     goto failure;

   }

   dstOffsetToIndex = ntohl(dstOffsetToIndex);

   /* Write out the new MAR file size */

   sizeOfEntireMAR += signatureSectionLength;

   if (!hasSignatureBlock) {

     sizeOfEntireMAR += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);

   }

   /* Write out the MAR size */

   sizeOfEntireMAR = HOST_TO_NETWORK64(sizeOfEntireMAR);

   if (WriteAndUpdateSignatures(fpDest, &sizeOfEntireMAR,

                                sizeof(sizeOfEntireMAR), ctxs, certCount,

                                "size of MAR")) {

     goto failure;

   }

   sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);

   /* Write out the number of signatures */

   numSignatures = certCount;

   numSignatures = htonl(numSignatures);

   if (WriteAndUpdateSignatures(fpDest, &numSignatures,

                                sizeof(numSignatures), ctxs, certCount,

                                "num signatures")) {

     goto failure;

   }

   numSignatures = ntohl(numSignatures);

   signaturePlaceholderOffset = ftello(fpDest);

   for (k = 0; k < certCount; k++) {

     /* Write out the signature algorithm ID, Only an ID of 1 is supported */

     signatureAlgorithmID = htonl(1);

     if (WriteAndUpdateSignatures(fpDest, &signatureAlgorithmID,

                                  sizeof(signatureAlgorithmID),

                                  ctxs, certCount, "num signatures")) {

       goto failure;

     }

     signatureAlgorithmID = ntohl(signatureAlgorithmID);

     /* Write out the signature length */

     signatureLengths[k] = htonl(signatureLengths[k]);

     if (WriteAndUpdateSignatures(fpDest, &signatureLengths[k],

                                  sizeof(signatureLengths[k]),

                                  ctxs, certCount, "signature length")) {

       goto failure;

     }

     signatureLengths[k] = ntohl(signatureLengths[k]);

     /* Write out a placeholder for the signature, we'll come back to this later

       *** THIS IS NOT SIGNED because it is a placeholder that will be replaced

           below, plus it is going to be the signature itself. *** */

     memset(buf, 0, sizeof(buf));

     if (fwrite(buf, signatureLengths[k], 1, fpDest) != 1) {

       fprintf(stderr, "ERROR: Could not write signature length\n");

       goto failure;

     }

   }

   /* Write out the rest of the MAR excluding the index header and index

      offsetToIndex unfortunately has to remain 32-bit because for backwards

      compatibility with the old MAR file format. */

   if (ftello(fpSrc) > ((int64_t)offsetToIndex)) {

     fprintf(stderr, "ERROR: Index offset is too small.\n");

     goto failure;

   }

   numBytesToCopy = ((int64_t)offsetToIndex) - ftello(fpSrc);

   numChunks = numBytesToCopy / BLOCKSIZE;

   leftOver = numBytesToCopy % BLOCKSIZE;

   /* Read each file and write it to the MAR file */

   for (i = 0; i < numChunks; ++i) {

     if (ReadWriteAndUpdateSignatures(fpSrc, fpDest, buf,

                                      BLOCKSIZE, ctxs, certCount,

                                      "content block")) {

       goto failure;

     }

   }

   /* Write out the left over */

   if (ReadWriteAndUpdateSignatures(fpSrc, fpDest, buf,

                                    leftOver, ctxs, certCount,

                                    "left over content block")) {

     goto failure;

   }

   /* Length of the index */

   if (ReadWriteAndUpdateSignatures(fpSrc, fpDest, &indexLength,

                                    sizeof(indexLength), ctxs, certCount,

                                    "index length")) {

     goto failure;

   }

   indexLength = ntohl(indexLength);

   /* Consume the index and adjust each index by signatureSectionLength */

   indexBuf = malloc(indexLength);

   indexBufLoc = indexBuf;

   if (fread(indexBuf, indexLength, 1, fpSrc) != 1) {

     fprintf(stderr, "ERROR: Could not read index\n");

     goto failure;

   }

   /* Adjust each entry in the index */

   if (hasSignatureBlock) {

     AdjustIndexContentOffsets(indexBuf, indexLength, signatureSectionLength);

   } else {

     AdjustIndexContentOffsets(indexBuf, indexLength, 

                               sizeof(sizeOfEntireMAR) + 

                               sizeof(numSignatures) + 

                               signatureSectionLength);

   }

   if (WriteAndUpdateSignatures(fpDest, indexBuf,

                                indexLength, ctxs, certCount, "index")) {

     goto failure;

   }

   /* Ensure that we don't sign a file that is too large to be accepted by

      the verification function. */

   if (ftello(fpDest) > MAX_SIZE_OF_MAR_FILE) {

     goto failure;

   }

   for (k = 0; k < certCount; k++) {

     /* Get the signature */

     if (SGN_End(ctxs[k], &secItems[k]) != SECSuccess) {

       fprintf(stderr, "ERROR: Could not end signature context\n");

       goto failure;

     }

     if (signatureLengths[k] != secItems[k].len) {

       fprintf(stderr, "ERROR: Signature is not the expected length\n");

       goto failure;

     }

   }

   /* Get back to the location of the signature placeholder */

   if (fseeko(fpDest, signaturePlaceholderOffset, SEEK_SET)) {

     fprintf(stderr, "ERROR: Could not seek to signature offset\n");

     goto failure;

   }

   for (k = 0; k < certCount; k++) {

     /* Skip to the position of the next signature */

     if (fseeko(fpDest, sizeof(signatureAlgorithmID) +

                sizeof(signatureLengths[k]), SEEK_CUR)) {

       fprintf(stderr, "ERROR: Could not seek to signature offset\n");

       goto failure;

     }

     /* Write out the calculated signature.

       *** THIS IS NOT SIGNED because it is the signature itself. *** */

     if (fwrite(secItems[k].data, secItems[k].len, 1, fpDest) != 1) {

       fprintf(stderr, "ERROR: Could not write signature\n");

       goto failure;

     }

   }

   rv = 0;

 failure: 

   if (fpSrc) {

     fclose(fpSrc);

   }

   if (fpDest) {

     fclose(fpDest);

   }

   if (rv) {

     remove(dest);

   }

   if (indexBuf) { 

     free(indexBuf);

   }

   /* Cleanup */

   for (k = 0; k < certCount; k++) {

     if (ctxs[k]) {

       SGN_DestroyContext(ctxs[k], PR_TRUE);

     }

     if (certs[k]) {

       CERT_DestroyCertificate(certs[k]);

     }

     if (privKeys[k]) {

       SECKEY_DestroyPrivateKey(privKeys[k]);

     }

     SECITEM_FreeItem(&secItems[k], PR_FALSE);

   }

   if (rv) {

     remove(dest);

   }

   return rv;

 }