libsecurity_smime/lib/cmsencode.c

   1 /*
   2  * The contents of this file are subject to the Mozilla Public
   3  * License Version 1.1 (the "License"); you may not use this file
   4  * except in compliance with the License. You may obtain a copy of
   5  * the License at http://www.mozilla.org/MPL/
   6  *
   7  * Software distributed under the License is distributed on an "AS
   8  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
   9  * implied. See the License for the specific language governing
  10  * rights and limitations under the License.
  11  *
  12  * The Original Code is the Netscape security libraries.
  13  *
  14  * The Initial Developer of the Original Code is Netscape
  15  * Communications Corporation.  Portions created by Netscape are
  16  * Copyright (C) 1994-2000 Netscape Communications Corporation.  All
  17  * Rights Reserved.
  18  *
  19  * Contributor(s):
  20  *
  21  * Alternatively, the contents of this file may be used under the
  22  * terms of the GNU General Public License Version 2 or later (the
  23  * "GPL"), in which case the provisions of the GPL are applicable
  24  * instead of those above.  If you wish to allow use of your
  25  * version of this file only under the terms of the GPL and not to
  26  * allow others to use your version of this file under the MPL,
  27  * indicate your decision by deleting the provisions above and
  28  * replace them with the notice and other provisions required by
  29  * the GPL.  If you do not delete the provisions above, a recipient
  30  * may use your version of this file under either the MPL or the
  31  * GPL.
  32  */
  33
  34 /*
  35  * CMS encoding.
  36  */
  37
  38 #include <Security/SecCmsEncoder.h>
  39 #include <Security/SecCmsContentInfo.h>
  40 #include <Security/SecCmsDigestContext.h>
  41 #include <Security/SecCmsMessage.h>
  42
  43 #include "cmslocal.h"
  44
  45 #include "secoid.h"
  46 #include "SecAsn1Item.h"
  47
  48 #include <security_asn1/secasn1.h>
  49 #include <security_asn1/secerr.h>
  50 #include <security_asn1/secport.h>
  51
  52 #include <Security/SecBase.h>
  53
  54 #include <limits.h>
  55
  56 struct nss_cms_encoder_output {
  57     SecCmsContentCallback outputfn;
  58     void *outputarg;
  59     CFMutableDataRef berData;
  60 };
  61
  62 struct SecCmsEncoderStr {
  63     SEC_ASN1EncoderContext *    ecx;            /* ASN.1 encoder context */
  64     Boolean                     ecxupdated;     /* true if data was handed in */
  65     SecCmsMessageRef            cmsg;           /* pointer to the root message */
  66     SECOidTag                   type;           /* type tag of the current content */
  67     SecCmsContent               content;        /* pointer to current content */
  68     struct nss_cms_encoder_output output;       /* output function */
  69     int                         error;          /* error code */
  70     SecCmsEncoderRef    childp7ecx;     /* link to child encoder context */
  71 };
  72
  73 static OSStatus nss_cms_before_data(SecCmsEncoderRef p7ecx);
  74 static OSStatus nss_cms_after_data(SecCmsEncoderRef p7ecx);
  75 static void nss_cms_encoder_update(void *arg, const char *data, size_t len);
  76 static OSStatus nss_cms_encoder_work_data(SecCmsEncoderRef p7ecx, SecAsn1Item * dest,
  77                              const unsigned char *data, size_t len,
  78                              Boolean final, Boolean innermost);
  79
  80 extern const SecAsn1Template SecCmsMessageTemplate[];
  81
  82 /*
  83  * The little output function that the ASN.1 encoder calls to hand
  84  * us bytes which we in turn hand back to our caller (via the callback
  85  * they gave us).
  86  */
  87 static void
  88 nss_cms_encoder_out(void *arg, const char *buf, size_t len,
  89                       int depth, SEC_ASN1EncodingPart data_kind)
  90 {
  91     struct nss_cms_encoder_output *output = (struct nss_cms_encoder_output *)arg;
  92
  93 #ifdef CMSDEBUG
  94     size_t i;
  95
  96     fprintf(stderr, "kind = %d, depth = %d, len = %d\n", data_kind, depth, len);
  97     for (i=0; i < len; i++) {
  98         fprintf(stderr, " %02x%s", (unsigned int)buf[i] & 0xff, ((i % 16) == 15) ? "\n" : "");
  99     }
 100     if ((i % 16) != 0)
 101         fprintf(stderr, "\n");
 102 #endif
 103
 104     if (output->outputfn != NULL)
 105         /* call output callback with DER data */
 106         output->outputfn(output->outputarg, buf, len);
 107
 108     if (output->berData != NULL) {
 109         /* store DER data in output->dest */
 110         CFDataAppendBytes(output->berData, (const UInt8 *)buf, len);
 111     }
 112 }
 113
 114 /*
 115  * nss_cms_encoder_notify - ASN.1 encoder callback
 116  *
 117  * this function is called by the ASN.1 encoder before and after the encoding of
 118  * every object. here, it is used to keep track of data structures, set up
 119  * encryption and/or digesting and possibly set up child encoders.
 120  */
 121 static void
 122 nss_cms_encoder_notify(void *arg, Boolean before, void *dest, int depth)
 123 {
 124     SecCmsEncoderRef p7ecx;
 125     SecCmsContentInfoRef rootcinfo, cinfo;
 126     Boolean after = !before;
 127     SECOidTag childtype;
 128     SecAsn1Item * item;
 129
 130     p7ecx = (SecCmsEncoderRef)arg;
 131     PORT_Assert(p7ecx != NULL);
 132
 133     rootcinfo = &(p7ecx->cmsg->contentInfo);
 134
 135 #ifdef CMSDEBUG
 136     fprintf(stderr, "%6.6s, dest = 0x%08x, depth = %d\n", before ? "before" : "after", dest, depth);
 137 #endif
 138
 139     /*
 140      * Watch for the content field, at which point we want to instruct
 141      * the ASN.1 encoder to start taking bytes from the buffer.
 142      */
 143     switch (p7ecx->type) {
 144     default:
 145     case SEC_OID_UNKNOWN:
 146         /* we're still in the root message */
 147         if (after && dest == &(rootcinfo->contentType)) {
 148             /* got the content type OID now - so find out the type tag */
 149             p7ecx->type = SecCmsContentInfoGetContentTypeTag(rootcinfo);
 150             /* set up a pointer to our current content */
 151             p7ecx->content = rootcinfo->content;
 152         }
 153         break;
 154
 155     case SEC_OID_PKCS7_DATA:
 156         if (before && dest == &(rootcinfo->rawContent)) {
 157             /* just set up encoder to grab from user - no encryption or digesting */
 158             if ((item = rootcinfo->content.data) != NULL)
 159                 (void)nss_cms_encoder_work_data(p7ecx, NULL, item->Data, item->Length, PR_TRUE, PR_TRUE);
 160             else
 161                 SEC_ASN1EncoderSetTakeFromBuf(p7ecx->ecx);
 162             SEC_ASN1EncoderClearNotifyProc(p7ecx->ecx); /* no need to get notified anymore */
 163         }
 164         break;
 165
 166     case SEC_OID_PKCS7_SIGNED_DATA:
 167     case SEC_OID_PKCS7_ENVELOPED_DATA:
 168     case SEC_OID_PKCS7_DIGESTED_DATA:
 169     case SEC_OID_PKCS7_ENCRYPTED_DATA:
 170
 171         /* when we know what the content is, we encode happily until we reach the inner content */
 172         cinfo = SecCmsContentGetContentInfo(p7ecx->content.pointer, p7ecx->type);
 173         childtype = SecCmsContentInfoGetContentTypeTag(cinfo);
 174
 175         if (after && dest == &(cinfo->contentType)) {
 176             /* we're right before encoding the data (if we have some or not) */
 177             /* (for encrypted data, we're right before the contentEncAlg which may change */
 178             /*  in nss_cms_before_data because of IV calculation when setting up encryption) */
 179             if (nss_cms_before_data(p7ecx) != SECSuccess)
 180                 p7ecx->error = PORT_GetError();
 181         }
 182         if (before && dest == &(cinfo->rawContent)) {
 183             if (childtype == SEC_OID_PKCS7_DATA && (item = cinfo->content.data) != NULL)
 184                 /* we have data - feed it in */
 185                 (void)nss_cms_encoder_work_data(p7ecx, NULL, item->Data, item->Length, PR_TRUE, PR_TRUE);
 186             else
 187                 /* else try to get it from user */
 188                 SEC_ASN1EncoderSetTakeFromBuf(p7ecx->ecx);
 189         }
 190         if (after && dest == &(cinfo->rawContent)) {
 191             if (nss_cms_after_data(p7ecx) != SECSuccess)
 192                 p7ecx->error = PORT_GetError();
 193             SEC_ASN1EncoderClearNotifyProc(p7ecx->ecx); /* no need to get notified anymore */
 194         }
 195         break;
 196     }
 197 }
 198
 199 /*
 200  * nss_cms_before_data - setup the current encoder to receive data
 201  */
 202 static OSStatus
 203 nss_cms_before_data(SecCmsEncoderRef p7ecx)
 204 {
 205     OSStatus rv;
 206     SECOidTag childtype;
 207     SecCmsContentInfoRef cinfo;
 208     SecCmsEncoderRef childp7ecx;
 209     const SecAsn1Template *template;
 210
 211     /* call _Encode_BeforeData handlers */
 212     switch (p7ecx->type) {
 213     case SEC_OID_PKCS7_SIGNED_DATA:
 214         /* we're encoding a signedData, so set up the digests */
 215         rv = SecCmsSignedDataEncodeBeforeData(p7ecx->content.signedData);
 216         break;
 217     case SEC_OID_PKCS7_DIGESTED_DATA:
 218         /* we're encoding a digestedData, so set up the digest */
 219         rv = SecCmsDigestedDataEncodeBeforeData(p7ecx->content.digestedData);
 220         break;
 221     case SEC_OID_PKCS7_ENVELOPED_DATA:
 222         rv = SecCmsEnvelopedDataEncodeBeforeData(p7ecx->content.envelopedData);
 223         break;
 224     case SEC_OID_PKCS7_ENCRYPTED_DATA:
 225         rv = SecCmsEncryptedDataEncodeBeforeData(p7ecx->content.encryptedData);
 226         break;
 227     default:
 228         rv = SECFailure;
 229     }
 230     if (rv != SECSuccess)
 231         return SECFailure;
 232
 233     /* ok, now we have a pointer to cinfo */
 234     /* find out what kind of data is encapsulated */
 235
 236     cinfo = SecCmsContentGetContentInfo(p7ecx->content.pointer, p7ecx->type);
 237     childtype = SecCmsContentInfoGetContentTypeTag(cinfo);
 238
 239     switch (childtype) {
 240     case SEC_OID_PKCS7_SIGNED_DATA:
 241     case SEC_OID_PKCS7_ENVELOPED_DATA:
 242     case SEC_OID_PKCS7_ENCRYPTED_DATA:
 243     case SEC_OID_PKCS7_DIGESTED_DATA:
 244 #if 0
 245     case SEC_OID_PKCS7_DATA:            /* XXX here also??? maybe yes! */
 246 #endif
 247         /* in these cases, we need to set up a child encoder! */
 248         /* create new encoder context */
 249         childp7ecx = PORT_ZAlloc(sizeof(struct SecCmsEncoderStr));
 250         if (childp7ecx == NULL)
 251             return SECFailure;
 252
 253         /* the CHILD encoder needs to hand its encoded data to the CURRENT encoder
 254          * (which will encrypt and/or digest it)
 255          * this needs to route back into our update function
 256          * which finds the lowest encoding context & encrypts and computes digests */
 257         childp7ecx->type = childtype;
 258         childp7ecx->content = cinfo->content;
 259         /* use the non-recursive update function here, of course */
 260         childp7ecx->output.outputfn = nss_cms_encoder_update;
 261         childp7ecx->output.outputarg = p7ecx;
 262         childp7ecx->output.berData = NULL;
 263         childp7ecx->cmsg = p7ecx->cmsg;
 264
 265         template = SecCmsUtilGetTemplateByTypeTag(childtype);
 266         if (template == NULL)
 267             goto loser;         /* cannot happen */
 268
 269         /* now initialize the data for encoding the first third */
 270         switch (childp7ecx->type) {
 271         case SEC_OID_PKCS7_SIGNED_DATA:
 272             rv = SecCmsSignedDataEncodeBeforeStart(cinfo->content.signedData);
 273             break;
 274         case SEC_OID_PKCS7_ENVELOPED_DATA:
 275             rv = SecCmsEnvelopedDataEncodeBeforeStart(cinfo->content.envelopedData);
 276             break;
 277         case SEC_OID_PKCS7_DIGESTED_DATA:
 278             rv = SecCmsDigestedDataEncodeBeforeStart(cinfo->content.digestedData);
 279             break;
 280         case SEC_OID_PKCS7_ENCRYPTED_DATA:
 281             rv = SecCmsEncryptedDataEncodeBeforeStart(cinfo->content.encryptedData);
 282             break;
 283         case SEC_OID_PKCS7_DATA:
 284             rv = SECSuccess;
 285             break;
 286         default:
 287             PORT_Assert(0);
 288             break;
 289         }
 290         if (rv != SECSuccess)
 291             goto loser;
 292
 293         /*
 294          * Initialize the BER encoder.
 295          */
 296         childp7ecx->ecx = SEC_ASN1EncoderStart(cinfo->content.pointer, template,
 297                                            nss_cms_encoder_out, &(childp7ecx->output));
 298         if (childp7ecx->ecx == NULL)
 299             goto loser;
 300
 301         childp7ecx->ecxupdated = PR_FALSE;
 302
 303         /*
 304          * Indicate that we are streaming.  We will be streaming until we
 305          * get past the contents bytes.
 306          */
 307         SEC_ASN1EncoderSetStreaming(childp7ecx->ecx);
 308
 309         /*
 310          * The notify function will watch for the contents field.
 311          */
 312         SEC_ASN1EncoderSetNotifyProc(childp7ecx->ecx, nss_cms_encoder_notify, childp7ecx);
 313
 314         /* please note that we are NOT calling SEC_ASN1EncoderUpdate here to kick off the */
 315         /* encoding process - we'll do that from the update function instead */
 316         /* otherwise we'd be encoding data from a call of the notify function of the */
 317         /* parent encoder (which would not work) */
 318
 319         /* this will kick off the encoding process & encode everything up to the content bytes,
 320          * at which point the notify function sets streaming mode (and possibly creates
 321          * another child encoder). */
 322         if (SEC_ASN1EncoderUpdate(childp7ecx->ecx, NULL, 0) != SECSuccess)
 323             goto loser;
 324
 325         p7ecx->childp7ecx = childp7ecx;
 326         break;
 327
 328     case SEC_OID_PKCS7_DATA:
 329         p7ecx->childp7ecx = NULL;
 330         break;
 331     default:
 332         /* we do not know this type */
 333         p7ecx->error = SEC_ERROR_BAD_DER;
 334         break;
 335     }
 336
 337     return SECSuccess;
 338
 339 loser:
 340     if (childp7ecx) {
 341         if (childp7ecx->ecx)
 342             SEC_ASN1EncoderFinish(childp7ecx->ecx);
 343         PORT_Free(childp7ecx);
 344     }
 345     return SECFailure;
 346 }
 347
 348 static OSStatus
 349 nss_cms_after_data(SecCmsEncoderRef p7ecx)
 350 {
 351     OSStatus rv = SECFailure;
 352
 353     switch (p7ecx->type) {
 354     case SEC_OID_PKCS7_SIGNED_DATA:
 355         /* this will finish the digests and sign */
 356         rv = SecCmsSignedDataEncodeAfterData(p7ecx->content.signedData);
 357         break;
 358     case SEC_OID_PKCS7_ENVELOPED_DATA:
 359         rv = SecCmsEnvelopedDataEncodeAfterData(p7ecx->content.envelopedData);
 360         break;
 361     case SEC_OID_PKCS7_DIGESTED_DATA:
 362         rv = SecCmsDigestedDataEncodeAfterData(p7ecx->content.digestedData);
 363         break;
 364     case SEC_OID_PKCS7_ENCRYPTED_DATA:
 365         rv = SecCmsEncryptedDataEncodeAfterData(p7ecx->content.encryptedData);
 366         break;
 367     case SEC_OID_PKCS7_DATA:
 368         /* do nothing */
 369         break;
 370     default:
 371         rv = SECFailure;
 372         break;
 373     }
 374     return rv;
 375 }
 376
 377 /*
 378  * nss_cms_encoder_work_data - process incoming data
 379  *
 380  * (from the user or the next encoding layer)
 381  * Here, we need to digest and/or encrypt, then pass it on
 382  *
 383  */
 384 static OSStatus
 385 nss_cms_encoder_work_data(SecCmsEncoderRef p7ecx, SecAsn1Item * dest,
 386                              const unsigned char *data, size_t len,
 387                              Boolean final, Boolean innermost)
 388 {
 389     unsigned char *buf = NULL;
 390     OSStatus rv;
 391     SecCmsContentInfoRef cinfo;
 392
 393     rv = SECSuccess;            /* may as well be optimistic */
 394
 395     /*
 396      * We should really have data to process, or we should be trying
 397      * to finish/flush the last block.  (This is an overly paranoid
 398      * check since all callers are in this file and simple inspection
 399      * proves they do it right.  But it could find a bug in future
 400      * modifications/development, that is why it is here.)
 401      */
 402     PORT_Assert ((data != NULL && len) || final);
 403     PORT_Assert (len < UINT_MAX); /* overflow check for later cast */
 404
 405     /* we got data (either from the caller, or from a lower level encoder) */
 406     cinfo = SecCmsContentGetContentInfo(p7ecx->content.pointer, p7ecx->type);
 407
 408     /* Update the running digest. */
 409     if (len && cinfo->digcx != NULL)
 410         SecCmsDigestContextUpdate(cinfo->digcx, data, len);
 411
 412     /* Encrypt this chunk. */
 413     if (cinfo->ciphcx != NULL) {
 414         unsigned int inlen;     /* length of data being encrypted */
 415         unsigned int outlen = 0;        /* length of encrypted data */
 416         unsigned int buflen;    /* length available for encrypted data */
 417
 418         /* 64 bits cast: only an issue if unsigned int is smaller than size_t.
 419            Worst case is you will truncate a CMS blob bigger than 4GB when
 420            encrypting */
 421         inlen = (unsigned int)len;
 422
 423         buflen = SecCmsCipherContextEncryptLength(cinfo->ciphcx, inlen, final);
 424         if (buflen == 0) {
 425             /*
 426              * No output is expected, but the input data may be buffered
 427              * so we still have to call Encrypt.
 428              */
 429             rv = SecCmsCipherContextEncrypt(cinfo->ciphcx, NULL, NULL, 0,
 430                                    data, inlen, final);
 431             if (final) {
 432                 len = 0;
 433                 goto done;
 434             }
 435             return rv;
 436         }
 437
 438         if (dest != NULL)
 439             buf = (unsigned char*)PORT_ArenaAlloc(p7ecx->cmsg->poolp, buflen);
 440         else
 441             buf = (unsigned char*)PORT_Alloc(buflen);
 442
 443         if (buf == NULL) {
 444             rv = SECFailure;
 445         } else {
 446             rv = SecCmsCipherContextEncrypt(cinfo->ciphcx, buf, &outlen, buflen,
 447                                    data, inlen, final);
 448             data = buf;
 449             len = outlen;
 450         }
 451         if (rv != SECSuccess)
 452             /* encryption or malloc failed? */
 453             return rv;
 454     }
 455
 456
 457     /*
 458      * at this point (data,len) has everything we'd like to give to the CURRENT encoder
 459      * (which will encode it, then hand it back to the user or the parent encoder)
 460      * We don't encode the data if we're innermost and we're told not to include the data
 461      */
 462     if (p7ecx->ecx != NULL && len && (!innermost || cinfo->rawContent != NULL))
 463         rv = SEC_ASN1EncoderUpdate(p7ecx->ecx, (const char *)data, len);
 464
 465 done:
 466
 467     if (cinfo->ciphcx != NULL) {
 468         if (dest != NULL) {
 469             dest->Data = buf;
 470             dest->Length = len;
 471         } else if (buf != NULL) {
 472             PORT_Free (buf);
 473         }
 474     }
 475     return rv;
 476 }
 477
 478 /*
 479  * nss_cms_encoder_update - deliver encoded data to the next higher level
 480  *
 481  * no recursion here because we REALLY want to end up at the next higher encoder!
 482  */
 483 static void
 484 nss_cms_encoder_update(void *arg, const char *data, size_t len)
 485 {
 486     /* XXX Error handling needs help.  Return what?  Do "Finish" on failure? */
 487     SecCmsEncoderRef p7ecx = (SecCmsEncoderRef)arg;
 488
 489     (void)nss_cms_encoder_work_data (p7ecx, NULL, (const unsigned char *)data, len, PR_FALSE, PR_FALSE);
 490 }
 491
 492 /*
 493  * SecCmsEncoderCreate - set up encoding of a CMS message
 494  *
 495  * "cmsg" - message to encode
 496  * "outputfn", "outputarg" - callback function for delivery of DER-encoded output
 497  *                           will not be called if NULL.
 498  * "dest" - if non-NULL, pointer to SecAsn1Item that will hold the DER-encoded output
 499  * "destpoolp" - pool to allocate DER-encoded output in
 500  * "pwfn", pwfn_arg" - callback function for getting token password
 501  * "decrypt_key_cb", "decrypt_key_cb_arg" - callback function for getting bulk key for encryptedData
 502  * "detached_digestalgs", "detached_digests" - digests from detached content
 503  */
 504 OSStatus
 505 SecCmsEncoderCreate(SecCmsMessageRef cmsg,
 506                     SecCmsContentCallback outputfn, void *outputarg,
 507                     CFMutableDataRef outBer,
 508                     PK11PasswordFunc pwfn, void *pwfn_arg,
 509                     SecCmsGetDecryptKeyCallback decrypt_key_cb, void *decrypt_key_cb_arg,
 510                     SecCmsEncoderRef *outEncoder)
 511 {
 512     SecCmsEncoderRef p7ecx;
 513     OSStatus result;
 514     SecCmsContentInfoRef cinfo;
 515
 516     SecCmsMessageSetEncodingParams(cmsg, pwfn, pwfn_arg, decrypt_key_cb, decrypt_key_cb_arg);
 517
 518     p7ecx = (SecCmsEncoderRef)PORT_ZAlloc(sizeof(struct SecCmsEncoderStr));
 519     if (p7ecx == NULL) {
 520         result = errSecAllocate;
 521         goto loser;
 522     }
 523
 524     p7ecx->cmsg = cmsg;
 525     p7ecx->output.outputfn = outputfn;
 526     p7ecx->output.outputarg = outputarg;
 527     p7ecx->output.berData = outBer;
 528
 529     p7ecx->type = SEC_OID_UNKNOWN;
 530
 531     cinfo = SecCmsMessageGetContentInfo(cmsg);
 532
 533     switch (SecCmsContentInfoGetContentTypeTag(cinfo)) {
 534     case SEC_OID_PKCS7_SIGNED_DATA:
 535         result = SecCmsSignedDataEncodeBeforeStart(cinfo->content.signedData);
 536         break;
 537     case SEC_OID_PKCS7_ENVELOPED_DATA:
 538         result = SecCmsEnvelopedDataEncodeBeforeStart(cinfo->content.envelopedData);
 539         break;
 540     case SEC_OID_PKCS7_DIGESTED_DATA:
 541         result = SecCmsDigestedDataEncodeBeforeStart(cinfo->content.digestedData);
 542         break;
 543     case SEC_OID_PKCS7_ENCRYPTED_DATA:
 544         result = SecCmsEncryptedDataEncodeBeforeStart(cinfo->content.encryptedData);
 545         break;
 546     default:
 547         /* @@@ We need a better error for unsupported message types. */
 548         result = errSecParam;
 549         break;
 550     }
 551     if (result)
 552         goto loser;
 553
 554     /* Initialize the BER encoder.
 555      * Note that this will not encode anything until the first call to SEC_ASN1EncoderUpdate */
 556     p7ecx->ecx = SEC_ASN1EncoderStart(cmsg, SecCmsMessageTemplate,
 557                                       nss_cms_encoder_out, &(p7ecx->output));
 558     if (p7ecx->ecx == NULL) {
 559         result = PORT_GetError();
 560         PORT_Free (p7ecx);
 561         goto loser;
 562     }
 563     p7ecx->ecxupdated = PR_FALSE;
 564
 565     /*
 566      * Indicate that we are streaming.  We will be streaming until we
 567      * get past the contents bytes.
 568      */
 569     SEC_ASN1EncoderSetStreaming(p7ecx->ecx);
 570
 571     /*
 572      * The notify function will watch for the contents field.
 573      */
 574     SEC_ASN1EncoderSetNotifyProc(p7ecx->ecx, nss_cms_encoder_notify, p7ecx);
 575
 576     /* this will kick off the encoding process & encode everything up to the content bytes,
 577      * at which point the notify function sets streaming mode (and possibly creates
 578      * a child encoder). */
 579     if (SEC_ASN1EncoderUpdate(p7ecx->ecx, NULL, 0) != SECSuccess) {
 580         result = PORT_GetError();
 581         PORT_Free (p7ecx);
 582         goto loser;
 583     }
 584
 585     *outEncoder = p7ecx;
 586 loser:
 587     return result;
 588 }
 589
 590 /*
 591  * SecCmsEncoderUpdate - take content data delivery from the user
 592  *
 593  * "p7ecx" - encoder context
 594  * "data" - content data
 595  * "len" - length of content data
 596  *
 597  * need to find the lowest level (and call SEC_ASN1EncoderUpdate on the way down),
 598  * then hand the data to the work_data fn
 599  */
 600 OSStatus
 601 SecCmsEncoderUpdate(SecCmsEncoderRef p7ecx, const void *data, CFIndex len)
 602 {
 603     OSStatus result;
 604     SecCmsContentInfoRef cinfo;
 605     SECOidTag childtype;
 606
 607     if (!p7ecx) {
 608         return errSecParam;
 609     }
 610
 611     if (p7ecx->error)
 612         return p7ecx->error;
 613
 614     /* hand data to the innermost decoder */
 615     if (p7ecx->childp7ecx) {
 616         /* recursion here */
 617         result = SecCmsEncoderUpdate(p7ecx->childp7ecx, data, len);
 618     } else {
 619         /* we are at innermost decoder */
 620         /* find out about our inner content type - must be data */
 621         cinfo = SecCmsContentGetContentInfo(p7ecx->content.pointer, p7ecx->type);
 622         childtype = SecCmsContentInfoGetContentTypeTag(cinfo);
 623         if (childtype != SEC_OID_PKCS7_DATA)
 624             return errSecParam; /* @@@ Maybe come up with a better error? */
 625         /* and we must not have preset data */
 626         if (cinfo->content.data != NULL)
 627             return errSecParam; /* @@@ Maybe come up with a better error? */
 628
 629         /*  hand it the data so it can encode it (let DER trickle up the chain) */
 630         result = nss_cms_encoder_work_data(p7ecx, NULL, (const unsigned char *)data, len, PR_FALSE, PR_TRUE);
 631         if (result)
 632             result = PORT_GetError();
 633     }
 634     return result;
 635 }
 636
 637 /*
 638  * SecCmsEncoderDestroy - stop all encoding
 639  *
 640  * we need to walk down the chain of encoders and the finish them from the innermost out
 641  */
 642 void
 643 SecCmsEncoderDestroy(SecCmsEncoderRef p7ecx)
 644 {
 645     /* XXX do this right! */
 646
 647     /*
 648      * Finish any inner decoders before us so that all the encoded data is flushed
 649      * This basically finishes all the decoders from the innermost to the outermost.
 650      * Finishing an inner decoder may result in data being updated to the outer decoder
 651      * while we are already in SecCmsEncoderFinish, but that's allright.
 652      */
 653     if (p7ecx->childp7ecx)
 654         SecCmsEncoderDestroy(p7ecx->childp7ecx); /* frees p7ecx->childp7ecx */
 655
 656     /*
 657      * On the way back up, there will be no more data (if we had an
 658      * inner encoder, it is done now!)
 659      * Flush out any remaining data and/or finish digests.
 660      */
 661     if (nss_cms_encoder_work_data(p7ecx, NULL, NULL, 0, PR_TRUE, (p7ecx->childp7ecx == NULL)))
 662         goto loser;
 663
 664     p7ecx->childp7ecx = NULL;
 665
 666     /* kick the encoder back into working mode again.
 667      * We turn off streaming stuff (which will cause the encoder to continue
 668      * encoding happily, now that we have all the data (like digests) ready for it).
 669      */
 670     SEC_ASN1EncoderClearTakeFromBuf(p7ecx->ecx);
 671     SEC_ASN1EncoderClearStreaming(p7ecx->ecx);
 672
 673     /* now that TakeFromBuf is off, this will kick this encoder to finish encoding */
 674     SEC_ASN1EncoderUpdate(p7ecx->ecx, NULL, 0);
 675
 676 loser:
 677     SEC_ASN1EncoderFinish(p7ecx->ecx);
 678     PORT_Free (p7ecx);
 679 }
 680
 681 /*
 682  * SecCmsEncoderFinish - signal the end of data
 683  *
 684  * we need to walk down the chain of encoders and the finish them from the innermost out
 685  */
 686 OSStatus
 687 SecCmsEncoderFinish(SecCmsEncoderRef p7ecx)
 688 {
 689     OSStatus result;
 690     SecCmsContentInfoRef cinfo;
 691     SECOidTag childtype;
 692
 693     /*
 694      * Finish any inner decoders before us so that all the encoded data is flushed
 695      * This basically finishes all the decoders from the innermost to the outermost.
 696      * Finishing an inner decoder may result in data being updated to the outer decoder
 697      * while we are already in SecCmsEncoderFinish, but that's allright.
 698      */
 699     if (p7ecx->childp7ecx) {
 700         result = SecCmsEncoderFinish(p7ecx->childp7ecx); /* frees p7ecx->childp7ecx */
 701         if (result)
 702             goto loser;
 703     }
 704
 705     /*
 706      * On the way back up, there will be no more data (if we had an
 707      * inner encoder, it is done now!)
 708      * Flush out any remaining data and/or finish digests.
 709      */
 710     result = nss_cms_encoder_work_data(p7ecx, NULL, NULL, 0, PR_TRUE, (p7ecx->childp7ecx == NULL));
 711     if (result) {
 712         result = PORT_GetError();
 713         goto loser;
 714     }
 715
 716     p7ecx->childp7ecx = NULL;
 717
 718     /* find out about our inner content type - must be data */
 719     cinfo = SecCmsContentGetContentInfo(p7ecx->content.pointer, p7ecx->type);
 720     childtype = SecCmsContentInfoGetContentTypeTag(cinfo);
 721     if (childtype == SEC_OID_PKCS7_DATA && cinfo->content.data == NULL) {
 722         SEC_ASN1EncoderClearTakeFromBuf(p7ecx->ecx);
 723         /* now that TakeFromBuf is off, this will kick this encoder to finish encoding */
 724         result = SEC_ASN1EncoderUpdate(p7ecx->ecx, NULL, 0);
 725         if (result)
 726             result = PORT_GetError();
 727     }
 728
 729     SEC_ASN1EncoderClearStreaming(p7ecx->ecx);
 730
 731     if (p7ecx->error && !result)
 732         result = p7ecx->error;
 733
 734 loser:
 735     SEC_ASN1EncoderFinish(p7ecx->ecx);
 736     PORT_Free (p7ecx);
 737     return result;
 738 }
 739
 740 OSStatus
 741 SecCmsMessageEncode(SecCmsMessageRef cmsg, const SecAsn1Item *input,
 742                     CFMutableDataRef outBer)
 743 {
 744     SecCmsEncoderRef encoder = NULL;
 745     OSStatus result;
 746
 747     if (!cmsg || !outBer) {
 748         result = errSecParam;
 749         goto loser;
 750     }
 751
 752     result = SecCmsEncoderCreate(cmsg, 0, 0, outBer, 0, 0, 0, 0, &encoder);
 753     if (result)
 754         goto loser;
 755
 756     if (input) {
 757         result = SecCmsEncoderUpdate(encoder, input->Data, input->Length);
 758         if (result) {
 759             SecCmsEncoderDestroy(encoder);
 760             goto loser;
 761         }
 762     }
 763     result = SecCmsEncoderFinish(encoder);
 764
 765 loser:
 766     return result;
 767 }