libsecurity_smime/lib/cmsdigest.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 digesting.
  36  */
  37 #include <assert.h>
  38
  39 #include "cmslocal.h"
  40
  41 #include "SecAsn1Item.h"
  42 #include "secoid.h"
  43
  44 #include <security_asn1/secerr.h>
  45 #include <security_asn1/secport.h>
  46
  47 #include <CommonCrypto/CommonDigest.h>
  48
  49 #include <Security/SecCmsDigestContext.h>
  50
  51 /* Return the maximum value between S and T (and U) */
  52 #define MAX(S, T) ({__typeof__(S) _max_s = S; __typeof__(T) _max_t = T; _max_s > _max_t ? _max_s : _max_t;})
  53 #define MAX_OF_3(S, T, U) ({__typeof__(U) _max_st = MAX(S,T); MAX(_max_st,U);})
  54
  55 struct SecCmsDigestContextStr {
  56     PLArenaPool *       poolp;
  57     Boolean             saw_contents;
  58     int                 digcnt;
  59     void **             digobjs;
  60     SECAlgorithmID **   digestalgs;
  61 };
  62
  63 /*
  64  * SecCmsDigestContextStartMultiple - start digest calculation using all the
  65  *  digest algorithms in "digestalgs" in parallel.
  66  */
  67 SecCmsDigestContextRef
  68 SecCmsDigestContextStartMultiple(SECAlgorithmID **digestalgs)
  69 {
  70     PLArenaPool *poolp;
  71     SecCmsDigestContextRef cmsdigcx;
  72     void * digobj;
  73     int digcnt;
  74     int i;
  75
  76     poolp = PORT_NewArena(1024);
  77     if (poolp == NULL) {
  78         goto loser;
  79     }
  80
  81     digcnt = (digestalgs == NULL) ? 0 : SecCmsArrayCount((void **)digestalgs);
  82
  83     cmsdigcx = (SecCmsDigestContextRef)PORT_ArenaAlloc(poolp, sizeof(struct SecCmsDigestContextStr));
  84     if (cmsdigcx == NULL) {
  85         goto loser;
  86     }
  87     cmsdigcx->poolp = poolp;
  88
  89     if (digcnt > 0) {
  90         /* Security check to prevent under-allocation */
  91         if (digcnt >= (int)((INT_MAX/(MAX(sizeof(void *),sizeof(SECAlgorithmID *))))-1)) {
  92             goto loser;
  93         }
  94         cmsdigcx->digobjs = (void**)PORT_ArenaAlloc(poolp, digcnt * sizeof(void *));
  95         if (cmsdigcx->digobjs == NULL) {
  96             goto loser;
  97         }
  98         cmsdigcx->digestalgs = (SECAlgorithmID **)PORT_ArenaZAlloc(poolp, (digcnt + 1) * sizeof(SECAlgorithmID *));
  99         if (cmsdigcx->digestalgs == NULL) {
 100             goto loser;
 101         }
 102     }
 103
 104     cmsdigcx->digcnt = 0;
 105
 106     /*
 107      * Create a digest object context for each algorithm.
 108      */
 109     for (i = 0; i < digcnt; i++) {
 110         digobj = SecCmsUtilGetHashObjByAlgID(digestalgs[i]);
 111         /*
 112          * Skip any algorithm we do not even recognize; obviously,
 113          * this could be a problem, but if it is critical then the
 114          * result will just be that the signature does not verify.
 115          * We do not necessarily want to error out here, because
 116          * the particular algorithm may not actually be important,
 117          * but we cannot know that until later.
 118          */
 119
 120         cmsdigcx->digobjs[cmsdigcx->digcnt] = digobj;
 121         cmsdigcx->digestalgs[cmsdigcx->digcnt] = PORT_ArenaAlloc(poolp, sizeof(SECAlgorithmID));
 122         if (SECITEM_CopyItem(poolp,
 123                              &(cmsdigcx->digestalgs[cmsdigcx->digcnt]->algorithm),
 124                              &(digestalgs[i]->algorithm))
 125             || SECITEM_CopyItem(poolp,
 126                                 &(cmsdigcx->digestalgs[cmsdigcx->digcnt]->parameters),
 127                                 &(digestalgs[i]->parameters))) {
 128             goto loser;
 129         }
 130         cmsdigcx->digcnt++;
 131     }
 132
 133     cmsdigcx->saw_contents = PR_FALSE;
 134
 135     return cmsdigcx;
 136
 137 loser:
 138     if (poolp) {
 139         PORT_FreeArena(poolp, PR_FALSE);
 140     }
 141
 142     return NULL;
 143 }
 144
 145 /*
 146  * SecCmsDigestContextStartSingle - same as SecCmsDigestContextStartMultiple, but
 147  *  only one algorithm.
 148  */
 149 SecCmsDigestContextRef
 150 SecCmsDigestContextStartSingle(SECAlgorithmID *digestalg)
 151 {
 152     SECAlgorithmID *digestalgs[] = { NULL, NULL };              /* fake array */
 153
 154     digestalgs[0] = digestalg;
 155     return SecCmsDigestContextStartMultiple(digestalgs);
 156 }
 157
 158 /*
 159  * SecCmsDigestContextUpdate - feed more data into the digest machine
 160  */
 161 void
 162 SecCmsDigestContextUpdate(SecCmsDigestContextRef cmsdigcx, const unsigned char *data, size_t len)
 163 {
 164     SecAsn1Item dataBuf;
 165     int i;
 166
 167     dataBuf.Length = len;
 168     dataBuf.Data = (uint8_t *)data;
 169     cmsdigcx->saw_contents = PR_TRUE;
 170     for (i = 0; i < cmsdigcx->digcnt; i++) {
 171         if (cmsdigcx->digobjs[i]) {
 172             /* 64 bits cast: worst case is we truncate the length and we dont hash all the data.
 173              This may cause an invalid CMS blob larger than 4GB to be validated. Unlikely, but
 174              possible security issue. There is no way to return an error here, but a check at
 175              the upper level may happen. */
 176             /*
 177              rdar://problem/20642513
 178              Let's just die a horrible death rather than have the security issue.
 179              CMS blob over 4GB?  Oh well.
 180              */
 181             if (len > UINT32_MAX) {
 182                 /* Ugh. */
 183                 abort();
 184             }
 185             assert(len<=UINT32_MAX); /* Debug check. Correct as long as CC_LONG is uint32_t */
 186             switch (SECOID_GetAlgorithmTag(cmsdigcx->digestalgs[i])) {
 187                 case SEC_OID_SHA1: CC_SHA1_Update((CC_SHA1_CTX *)cmsdigcx->digobjs[i], data, (CC_LONG)len); break;
 188                 case SEC_OID_MD5: CC_MD5_Update((CC_MD5_CTX *)cmsdigcx->digobjs[i], data, (CC_LONG)len); break;
 189                 case SEC_OID_SHA224: CC_SHA224_Update((CC_SHA256_CTX *)cmsdigcx->digobjs[i], data, (CC_LONG)len); break;
 190                 case SEC_OID_SHA256: CC_SHA256_Update((CC_SHA256_CTX *)cmsdigcx->digobjs[i], data, (CC_LONG)len); break;
 191                 case SEC_OID_SHA384: CC_SHA384_Update((CC_SHA512_CTX *)cmsdigcx->digobjs[i], data, (CC_LONG)len); break;
 192                 case SEC_OID_SHA512: CC_SHA512_Update((CC_SHA512_CTX *)cmsdigcx->digobjs[i], data, (CC_LONG)len); break;
 193                 default:
 194                     break;
 195             }
 196         }
 197     }
 198 }
 199
 200 /*
 201  * SecCmsDigestContextCancel - cancel digesting operation
 202  */
 203 void
 204 SecCmsDigestContextCancel(SecCmsDigestContextRef cmsdigcx)
 205 {
 206     int i;
 207
 208     for (i = 0; i < cmsdigcx->digcnt; i++) {
 209         if (cmsdigcx->digobjs && cmsdigcx->digobjs[i]) {
 210             free(cmsdigcx->digobjs[i]);
 211             cmsdigcx->digobjs[i] = NULL;
 212         }
 213     }
 214
 215     PORT_FreeArena(cmsdigcx->poolp, PR_TRUE);
 216 }
 217
 218 /*
 219  * SecCmsDigestContextDestroy - delete a digesting operation
 220  */
 221 void
 222 SecCmsDigestContextDestroy(SecCmsDigestContextRef cmsdigcx)
 223 {
 224     SecCmsDigestContextCancel(cmsdigcx);
 225 }
 226
 227 /*
 228  * SecCmsDigestContextFinishMultiple - finish the digests
 229  * Note that on iOS, this call only frees the digest objects and requires a call to SecCmsDisgestContextDestroy
 230  * or SecCmsDisgestContextCancel (because the digests are allocated out of the context's pool).
 231  * The macOS version cancels and frees the digest context (because the digests are allocated from an input arena pool).
 232  */
 233 OSStatus
 234 SecCmsDigestContextFinishMultiple(SecCmsDigestContextRef cmsdigcx,
 235                                   SECAlgorithmID ***digestalgsp,
 236                                   SecAsn1Item * **digestsp)
 237 {
 238     void * digobj;
 239     SecAsn1Item **digests, *digest;
 240     SECAlgorithmID **digestalgs;
 241     int i;
 242     void *mark;
 243     OSStatus rv = SECFailure;
 244
 245     assert(cmsdigcx != NULL);
 246
 247     /* A message with no contents (just signed attributes) is used within SCEP */
 248 #if 0
 249     /* no contents? do not update digests */
 250     if (digestsp == NULL || !cmsdigcx->saw_contents) {
 251         for (i = 0; i < cmsdigcx->digcnt; i++) {
 252             if (cmsdigcx->digobjs[i]) {
 253                 free(cmsdigcx->digobjs[i]);
 254             }
 255         }
 256         rv = SECSuccess;
 257         if (digestsp) {
 258             *digestsp = NULL;
 259         }
 260         goto cleanup;
 261     }
 262 #endif
 263
 264     assert(digestsp != NULL);
 265     assert(digestalgsp != NULL);
 266
 267     mark = PORT_ArenaMark (cmsdigcx->poolp);
 268
 269     /* Security check to prevent under-allocation */
 270     if (cmsdigcx->digcnt >= (int)((INT_MAX/(MAX_OF_3(sizeof(SECAlgorithmID *),sizeof(SecAsn1Item *),sizeof(SecAsn1Item))))-1)) {
 271         goto loser;
 272     }
 273     /* allocate digest array & SecAsn1Items on arena */
 274     digestalgs = (SECAlgorithmID **)PORT_ArenaZAlloc(cmsdigcx->poolp, (cmsdigcx->digcnt+1) * sizeof(SECAlgorithmID *));
 275     digests = (SecAsn1Item * *)PORT_ArenaZAlloc(cmsdigcx->poolp, (cmsdigcx->digcnt+1) * sizeof(SecAsn1Item *));
 276     digest = (SecAsn1Item *)PORT_ArenaZAlloc(cmsdigcx->poolp, cmsdigcx->digcnt * sizeof(SecAsn1Item));
 277     if (digestalgs == NULL || digests == NULL || digest == NULL) {
 278         goto loser;
 279     }
 280
 281     for (i = 0; i < cmsdigcx->digcnt; i++, digest++) {
 282         SECOidTag hash_alg = SECOID_GetAlgorithmTag(cmsdigcx->digestalgs[i]);
 283         int diglength = 0;
 284
 285         switch (hash_alg) {
 286             case SEC_OID_SHA1: diglength = CC_SHA1_DIGEST_LENGTH; break;
 287             case SEC_OID_MD5: diglength = CC_MD5_DIGEST_LENGTH; break;
 288             case SEC_OID_SHA224: diglength = CC_SHA224_DIGEST_LENGTH; break;
 289             case SEC_OID_SHA256: diglength = CC_SHA256_DIGEST_LENGTH; break;
 290             case SEC_OID_SHA384: diglength = CC_SHA384_DIGEST_LENGTH; break;
 291             case SEC_OID_SHA512: diglength = CC_SHA512_DIGEST_LENGTH; break;
 292             default: goto loser;
 293         }
 294
 295         digobj = cmsdigcx->digobjs[i];
 296         if (digobj) {
 297             digest->Data = (unsigned char*)PORT_ArenaAlloc(cmsdigcx->poolp, diglength);
 298             if (digest->Data == NULL)
 299                 goto loser;
 300             digest->Length = diglength;
 301             switch (hash_alg) {
 302                 case SEC_OID_SHA1: CC_SHA1_Final(digest->Data, digobj); break;
 303                 case SEC_OID_MD5: CC_MD5_Final(digest->Data, digobj); break;
 304                 case SEC_OID_SHA224: CC_SHA224_Final(digest->Data, digobj); break;
 305                 case SEC_OID_SHA256: CC_SHA256_Final(digest->Data, digobj); break;
 306                 case SEC_OID_SHA384: CC_SHA384_Final(digest->Data, digobj); break;
 307                 case SEC_OID_SHA512: CC_SHA512_Final(digest->Data, digobj); break;
 308                 default: goto loser;
 309             }
 310
 311             free(digobj);
 312             digestalgs[i] = cmsdigcx->digestalgs[i];
 313             digests[i] = digest;
 314         } else {
 315             digest->Data = NULL;
 316             digest->Length = 0;
 317         }
 318     }
 319     digestalgs[i] = NULL;
 320     digests[i] = NULL;
 321     *digestalgsp = digestalgs;
 322     *digestsp = digests;
 323
 324     rv = SECSuccess;
 325
 326 loser:
 327     if (rv == SECSuccess) {
 328         PORT_ArenaUnmark(cmsdigcx->poolp, mark);
 329     } else {
 330         PORT_ArenaRelease(cmsdigcx->poolp, mark);
 331     }
 332
 333     /*cleanup:*/
 334     /* Set things up so SecCmsDigestContextDestroy won't call CSSM_DeleteContext again. */
 335     cmsdigcx->digcnt = 0;
 336
 337     return rv;
 338 }
 339
 340 /*
 341  * SecCmsDigestContextFinishSingle - same as SecCmsDigestContextFinishMultiple,
 342  *  but for one digest.
 343  */
 344 OSStatus
 345 SecCmsDigestContextFinishSingle(SecCmsDigestContextRef cmsdigcx,
 346                                 SecAsn1Item * digest)
 347 {
 348     OSStatus rv = SECFailure;
 349     SecAsn1Item * *dp;
 350     SECAlgorithmID **ap;
 351
 352     /* get the digests into arena, then copy the first digest into poolp */
 353     if (SecCmsDigestContextFinishMultiple(cmsdigcx, &ap, &dp) != SECSuccess) {
 354         goto loser;
 355     }
 356
 357     /* Return the first element in the digest array. */
 358     if (digest) {
 359         *digest = *dp[0];
 360     }
 361
 362     rv = SECSuccess;
 363
 364 loser:
 365     return rv;
 366 }