Merge pull request #2084 from cconlon/cmsFeb19

Changes for CMS signedData default signed attributes

tests/api.c

@@ -21933,8 +21933,18 @@ static void test_wolfssl_PKCS7(void)
     AssertNotNull(pkcs7 = d2i_PKCS7(NULL, &p, len));
     AssertIntEQ(wolfSSL_PKCS7_verify(NULL, NULL, NULL, NULL, NULL,
                                               PKCS7_NOVERIFY), WOLFSSL_FAILURE);
+    PKCS7_free(pkcs7);
+
+    /* fail case, without PKCS7_NOVERIFY */
+    p = data;
+    AssertNotNull(pkcs7 = d2i_PKCS7(NULL, &p, len));
     AssertIntEQ(wolfSSL_PKCS7_verify(pkcs7, NULL, NULL, NULL, NULL,
                                                            0), WOLFSSL_FAILURE);
+    PKCS7_free(pkcs7);
+
+    /* success case, with PKCS7_NOVERIFY */
+    p = data;
+    AssertNotNull(pkcs7 = d2i_PKCS7(NULL, &p, len));
     AssertIntEQ(wolfSSL_PKCS7_verify(pkcs7, NULL, NULL, NULL, NULL,
                                               PKCS7_NOVERIFY), WOLFSSL_SUCCESS);
 

wolfcrypt/src/pkcs7.c

@@ -1458,6 +1458,7 @@ static int wc_PKCS7_BuildSignedAttributes(PKCS7* pkcs7, ESD* esd,
     int timeSz;
     PKCS7Attrib cannedAttribs[3];
 #endif
+    word32 idx = 0;
     word32 cannedAttribsCount;
 
     if (pkcs7 == NULL || esd == NULL || contentType == NULL ||
@@ -1466,6 +1467,7 @@ static int wc_PKCS7_BuildSignedAttributes(PKCS7* pkcs7, ESD* esd,
         return BAD_FUNC_ARG;
     }
 
+    if (pkcs7->skipDefaultSignedAttribs == 0) {
         hashSz = wc_HashGetDigestSize(esd->hashType);
         if (hashSz < 0)
             return hashSz;
@@ -1482,25 +1484,33 @@ static int wc_PKCS7_BuildSignedAttributes(PKCS7* pkcs7, ESD* esd,
 
         cannedAttribsCount = sizeof(cannedAttribs)/sizeof(PKCS7Attrib);
 
-    cannedAttribs[0].oid     = contentTypeOid;
+        cannedAttribs[idx].oid     = contentTypeOid;
-    cannedAttribs[0].oidSz   = contentTypeOidSz;
+        cannedAttribs[idx].oidSz   = contentTypeOidSz;
-    cannedAttribs[0].value   = contentType;
+        cannedAttribs[idx].value   = contentType;
-    cannedAttribs[0].valueSz = contentTypeSz;
+        cannedAttribs[idx].valueSz = contentTypeSz;
-    cannedAttribs[1].oid     = messageDigestOid;
+        idx++;
-    cannedAttribs[1].oidSz   = messageDigestOidSz;
-    cannedAttribs[1].value   = esd->contentDigest;
-    cannedAttribs[1].valueSz = hashSz + 2;  /* ASN.1 heading */
     #ifndef NO_ASN_TIME
-    cannedAttribs[2].oid     = signingTimeOid;
+        cannedAttribs[idx].oid     = signingTimeOid;
-    cannedAttribs[2].oidSz   = signingTimeOidSz;
+        cannedAttribs[idx].oidSz   = signingTimeOidSz;
-    cannedAttribs[2].value   = signingTime;
+        cannedAttribs[idx].value   = signingTime;
-    cannedAttribs[2].valueSz = timeSz;
+        cannedAttribs[idx].valueSz = timeSz;
+        idx++;
     #endif
+        cannedAttribs[idx].oid     = messageDigestOid;
+        cannedAttribs[idx].oidSz   = messageDigestOidSz;
+        cannedAttribs[idx].value   = esd->contentDigest;
+        cannedAttribs[idx].valueSz = hashSz + 2;  /* ASN.1 heading */
 
         esd->signedAttribsCount += cannedAttribsCount;
         esd->signedAttribsSz += EncodeAttributes(&esd->signedAttribs[0], 3,
                                              cannedAttribs, cannedAttribsCount);
+    } else {
+        esd->signedAttribsCount = 0;
+        esd->signedAttribsSz = 0;
+    }
 
+    /* add custom signed attributes if set */
+    if (pkcs7->signedAttribsSz > 0 && pkcs7->signedAttribs != NULL) {
         esd->signedAttribsCount += pkcs7->signedAttribsSz;
     #ifdef NO_ASN_TIME
         esd->signedAttribsSz += EncodeAttributes(&esd->signedAttribs[2], 4,
@@ -1509,6 +1519,7 @@ static int wc_PKCS7_BuildSignedAttributes(PKCS7* pkcs7, ESD* esd,
         esd->signedAttribsSz += EncodeAttributes(&esd->signedAttribs[3], 4,
                                   pkcs7->signedAttribs, pkcs7->signedAttribsSz);
     #endif
+    }
 
 #ifdef NO_ASN_TIME
     (void)signingTimeOidSz;
@@ -1648,7 +1659,7 @@ static int wc_PKCS7_BuildDigestInfo(PKCS7* pkcs7, byte* flatSignedAttribs,
     if (hashSz < 0)
         return hashSz;
 
-    if (pkcs7->signedAttribsSz != 0) {
+    if (flatSignedAttribsSz != 0) {
 
         if (flatSignedAttribs == NULL)
             return BAD_FUNC_ARG;
@@ -1951,9 +1962,8 @@ static int PKCS7_EncodeSigned(PKCS7* pkcs7, ESD* esd,
                                     digEncAlgoType, 0);
     signerInfoSz += esd->digEncAlgoIdSz;
 
-    if (pkcs7->signedAttribsSz != 0) {
+    /* build up signed attributes, include contentType, signingTime, and
-
+       messageDigest by default */
-        /* build up signed attributes */
     ret = wc_PKCS7_BuildSignedAttributes(pkcs7, esd, pkcs7->contentType,
                                  pkcs7->contentTypeSz,
                                  contentTypeOid, sizeof(contentTypeOid),
@@ -1967,6 +1977,7 @@ static int PKCS7_EncodeSigned(PKCS7* pkcs7, ESD* esd,
         return ret;
     }
 
+    if (esd->signedAttribsSz > 0) {
         flatSignedAttribs = (byte*)XMALLOC(esd->signedAttribsSz, pkcs7->heap,
                                                          DYNAMIC_TYPE_PKCS7);
         flatSignedAttribsSz = esd->signedAttribsSz;
@@ -1981,6 +1992,8 @@ static int PKCS7_EncodeSigned(PKCS7* pkcs7, ESD* esd,
                                    esd->signedAttribs, esd->signedAttribsCount);
         esd->signedAttribSetSz = SetImplicit(ASN_SET, 0, esd->signedAttribsSz,
                                                           esd->signedAttribSet);
+    } else {
+        esd->signedAttribSetSz = 0;
     }
 
     /* Calculate the final hash and encrypt it. */
@@ -2241,6 +2254,27 @@ int wc_PKCS7_SetDetached(PKCS7* pkcs7, word16 flag)
     return 0;
 }
 
+/* By default, SignedData bundles have the following signed attributes attached:
+ *     contentType (1.2.840.113549.1.9.3)
+ *     signgingTime (1.2.840.113549.1.9.5)
+ *     messageDigest (1.2.840.113549.1.9.4)
+ *
+ * Calling this API before wc_PKCS7_EncodeSignedData() will disable the
+ * inclusion of those attributes.
+ *
+ * pkcs7 - pointer to initialized PKCS7 structure
+ *
+ * Returns 0 on success, negative upon error. */
+int wc_PKCS7_NoDefaultSignedAttribs(PKCS7* pkcs7)
+{
+    if (pkcs7 == NULL)
+        return BAD_FUNC_ARG;
+
+    pkcs7->skipDefaultSignedAttribs = 1;
+
+    return 0;
+}
+
 /* return codes: >0: Size of signed PKCS7 output buffer, negative: error */
 int wc_PKCS7_EncodeSignedData(PKCS7* pkcs7, byte* output, word32 outputSz)
 {

wolfssl/wolfcrypt/pkcs7.h

@@ -284,6 +284,8 @@ struct PKCS7 {
 #endif
     word32 state;
 
+    word16 skipDefaultSignedAttribs:1; /* skip adding default signed attribs */
+
     /* !! NEW DATA MEMBERS MUST BE ADDED AT END !! */
 };
 
@@ -310,6 +312,7 @@ WOLFSSL_API int  wc_PKCS7_EncodeData(PKCS7* pkcs7, byte* output,
 
 /* CMS/PKCS#7 SignedData */
 WOLFSSL_API int  wc_PKCS7_SetDetached(PKCS7* pkcs7, word16 flag);
+WOLFSSL_API int  wc_PKCS7_NoDefaultSignedAttribs(PKCS7* pkcs7);
 WOLFSSL_API int  wc_PKCS7_EncodeSignedData(PKCS7* pkcs7,
                                           byte* output, word32 outputSz);
 WOLFSSL_API int  wc_PKCS7_EncodeSignedData_ex(PKCS7* pkcs7, const byte* hashBuf,