From d21e370822c7fb53fb484903587c06d55640fe53 Mon Sep 17 00:00:00 2001
From: Chris Conlon <chris@wolfssl.com>
Date: Thu, 27 Feb 2020 14:42:57 -0700
Subject: [PATCH 1/5] add support for PKCS7/CMS EnvelopedData with fragmented
 encrypted content

---
 tests/api.c               |   2 +-
 wolfcrypt/src/pkcs7.c     | 130 +++++++++++++++++++++++++++++---------
 wolfssl/wolfcrypt/pkcs7.h |   4 ++
 3 files changed, 105 insertions(+), 31 deletions(-)

diff --git a/tests/api.c b/tests/api.c
index 39fccc391..97c2cb4fc 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -18416,7 +18416,7 @@ static void test_wc_PKCS7_BER(void)
     XFILE  f;
     byte   der[4096];
 #ifndef NO_DES3
-    byte   decoded[1024];
+    byte   decoded[2048];
 #endif
     word32 derSz;
     int    ret;
diff --git a/wolfcrypt/src/pkcs7.c b/wolfcrypt/src/pkcs7.c
index 3231ce661..12494d970 100644
--- a/wolfcrypt/src/pkcs7.c
+++ b/wolfcrypt/src/pkcs7.c
@@ -1172,6 +1172,11 @@ void wc_PKCS7_Free(PKCS7* pkcs7)
         pkcs7->pkcs7Digest = NULL;
         pkcs7->pkcs7DigestSz = 0;
     }
+    if (pkcs7->cachedEncryptedContent != NULL) {
+        XFREE(pkcs7->cachedEncryptedContent, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
+        pkcs7->cachedEncryptedContent = NULL;
+        pkcs7->cachedEncryptedContentSz = 0;
+    }
 
     if (pkcs7->isDynamic) {
         pkcs7->isDynamic = 0;
@@ -9987,6 +9992,41 @@ WOLFSSL_API int wc_PKCS7_SetKey(PKCS7* pkcs7, byte* key, word32 keySz)
 }
 
 
+/* append data to encrypted content cache in PKCS7 structure
+ * return 0 on success, negative on error */
+static int PKCS7_CacheEncryptedContent(PKCS7* pkcs7, byte* in, word32 inSz)
+{
+    byte* oldCache;
+    word32 oldCacheSz;
+
+    if (pkcs7 == NULL || in == NULL)
+        return BAD_FUNC_ARG;
+
+    /* save pointer to old cache */
+    oldCache = pkcs7->cachedEncryptedContent;
+    oldCacheSz = pkcs7->cachedEncryptedContentSz;
+
+    /* re-allocate new buffer to fit appended data */
+    pkcs7->cachedEncryptedContent = (byte*)XMALLOC(oldCacheSz + inSz,
+            pkcs7->heap, DYNAMIC_TYPE_PKCS7);
+    if (pkcs7->cachedEncryptedContent == NULL) {
+        pkcs7->cachedEncryptedContentSz = 0;
+        XFREE(oldCache, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
+        return MEMORY_E;
+    }
+
+    if (oldCache != NULL) {
+        XMEMCPY(pkcs7->cachedEncryptedContent, oldCache, oldCacheSz);
+    }
+    XMEMCPY(pkcs7->cachedEncryptedContent + oldCacheSz, in, inSz);
+    pkcs7->cachedEncryptedContentSz += inSz;
+
+    XFREE(oldCache, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
+
+    return 0;
+}
+
+
 /* unwrap and decrypt PKCS#7 envelopedData object, return decoded size */
 WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
                                          word32 inSz, byte* output,
@@ -10009,6 +10049,7 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
     byte* pkiMsg    = in;
     word32 pkiMsgSz = inSz;
     byte* decryptedKey = NULL;
+    int encryptedContentTotalSz = 0;
     int encryptedContentSz = 0;
     byte padLen;
     byte* encryptedContent = NULL;
@@ -10223,27 +10264,51 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
             }
             idx++;
 
-            if (ret == 0 && GetLength(pkiMsg, &idx, &encryptedContentSz,
+            if (ret == 0 && GetLength(pkiMsg, &idx, &encryptedContentTotalSz,
                                                                pkiMsgSz) <= 0) {
                 ret = ASN_PARSE_E;
             }
 
             if (ret == 0 && explicitOctet) {
-                if (GetASNTag(pkiMsg, &idx, &tag, pkiMsgSz) < 0) {
-                    ret = ASN_PARSE_E;
-                    break;
-                }
+                /* encrypted content may be fragmented into multiple
+                 * consecutive OCTET STRINGs, if so loop through
+                 * collecting and caching encrypted content bytes */
+                localIdx = idx;
+                while (idx < (localIdx + encryptedContentTotalSz)) {
 
-                if (tag != ASN_OCTET_STRING) {
-                    ret = ASN_PARSE_E;
-                    break;
-                }
+                    if (GetASNTag(pkiMsg, &idx, &tag, pkiMsgSz) < 0) {
+                        ret = ASN_PARSE_E;
+                        break;
+                    }
 
-                if (ret == 0 && GetLength(pkiMsg, &idx, &encryptedContentSz,
-                            pkiMsgSz) <= 0) {
-                    ret = ASN_PARSE_E;
+                    if (tag != ASN_OCTET_STRING) {
+                        ret = ASN_PARSE_E;
+                        break;
+                    }
+
+                    if (ret == 0 && GetLength(pkiMsg, &idx,
+                                &encryptedContentSz, pkiMsgSz) <= 0) {
+                        ret = ASN_PARSE_E;
+                        break;
+                    }
+
+                    ret = PKCS7_CacheEncryptedContent(pkcs7, &pkiMsg[idx],
+                                                      encryptedContentSz);
+                    if (ret != 0) {
+                        break;
+                    }
+
+                    /* advance idx past encrypted content */
+                    idx += encryptedContentSz;
+                }
+            } else {
+                /* cache encrypted content, no OCTET STRING */
+                ret = PKCS7_CacheEncryptedContent(pkcs7, &pkiMsg[idx],
+                                                  encryptedContentTotalSz);
+                if (ret != 0) {
                     break;
                 }
+                idx += encryptedContentTotalSz;
             }
 
             if (ret != 0)
@@ -10253,10 +10318,9 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, &idx)) != 0) {
                 break;
             }
-            pkcs7->stream->expected = encryptedContentSz;
+            pkcs7->stream->expected = 0;
             wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, 0);
-            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz,
-                    encryptedContentSz);
+            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, 0);
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_ENV_5);
             FALL_THROUGH;
@@ -10269,8 +10333,7 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
                 return ret;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz,
-                    &encryptedContentSz);
+            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, NULL);
             tmpIv = pkcs7->stream->tmpIv;
 
             /* restore decrypted key */
@@ -10280,23 +10343,16 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
         #else
             ret = 0;
         #endif
-            encryptedContent = (byte*)XMALLOC(encryptedContentSz, pkcs7->heap,
-                                                       DYNAMIC_TYPE_PKCS7);
-            if (encryptedContent == NULL) {
-                ret = MEMORY_E;
-                break;
-            }
 
-            if (ret == 0) {
-                XMEMCPY(encryptedContent, &pkiMsg[idx], encryptedContentSz);
-            }
+            /* use cached content */
+            encryptedContent = pkcs7->cachedEncryptedContent;
+            encryptedContentSz = pkcs7->cachedEncryptedContentSz;
 
             /* decrypt encryptedContent */
             ret = wc_PKCS7_DecryptContent(pkcs7, encOID, decryptedKey,
                     blockKeySz, tmpIv, expBlockSz, NULL, 0, NULL, 0,
                     encryptedContent, encryptedContentSz, encryptedContent);
             if (ret != 0) {
-                XFREE(encryptedContent, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
                 break;
             }
 
@@ -10305,7 +10361,6 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
             /* copy plaintext to output */
             if (padLen > encryptedContentSz ||
                     (word32)(encryptedContentSz - padLen) > outputSz) {
-                XFREE(encryptedContent, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
                 ret = BUFFER_E;
                 break;
             }
@@ -10313,9 +10368,13 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
 
             /* free memory, zero out keys */
             ForceZero(decryptedKey, MAX_ENCRYPTED_KEY_SZ);
-            ForceZero(encryptedContent, encryptedContentSz);
-            XFREE(encryptedContent, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
             XFREE(decryptedKey, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
+            if (pkcs7->cachedEncryptedContent != NULL) {
+                XFREE(pkcs7->cachedEncryptedContent, pkcs7->heap,
+                      DYNAMIC_TYPE_PKCS7);
+                pkcs7->cachedEncryptedContent = NULL;
+                pkcs7->cachedEncryptedContentSz = 0;
+            }
 
             ret = encryptedContentSz - padLen;
         #ifndef NO_PKCS7_STREAM
@@ -10335,12 +10394,23 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
     if (ret < 0 && ret != WC_PKCS7_WANT_READ_E) {
         wc_PKCS7_ResetStream(pkcs7);
         wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_START);
+        if (pkcs7->cachedEncryptedContent != NULL) {
+            XFREE(pkcs7->cachedEncryptedContent, pkcs7->heap,
+                  DYNAMIC_TYPE_PKCS7);
+            pkcs7->cachedEncryptedContent = NULL;
+            pkcs7->cachedEncryptedContentSz = 0;
+        }
     }
 #else
     if (decryptedKey != NULL && ret < 0) {
         ForceZero(decryptedKey, MAX_ENCRYPTED_KEY_SZ);
         XFREE(decryptedKey, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
     }
+    if (pkcs7->cachedEncryptedContent != NULL && ret < 0) {
+        XFREE(pkcs7->cachedEncryptedContent, pkcs7->heap, DYNAMIC_TYPE_PKCS7);
+        pkcs7->cachedEncryptedContent = NULL;
+        pkcs7->cachedEncryptedContentSz = 0;
+    }
 #endif
     return ret;
 }
diff --git a/wolfssl/wolfcrypt/pkcs7.h b/wolfssl/wolfcrypt/pkcs7.h
index 840d94281..0292d1d07 100644
--- a/wolfssl/wolfcrypt/pkcs7.h
+++ b/wolfssl/wolfcrypt/pkcs7.h
@@ -330,6 +330,10 @@ struct PKCS7 {
 #if defined(HAVE_PKCS7_RSA_RAW_SIGN_CALLBACK) && !defined(NO_RSA)
     CallbackRsaSignRawDigest rsaSignRawDigestCb;
 #endif
+
+    /* used by DecodeEnvelopedData with multiple encrypted contents */
+    byte*  cachedEncryptedContent;
+    word32 cachedEncryptedContentSz;
     /* !! NEW DATA MEMBERS MUST BE ADDED AT END !! */
 };
 

From debb79269017a647260c3a97560b467cf8837b35 Mon Sep 17 00:00:00 2001
From: Chris Conlon <chris@wolfssl.com>
Date: Fri, 28 Feb 2020 17:55:19 -0700
Subject: [PATCH 2/5] fix PKCS7 encrypted content decoding for streaming API
 usage

---
 wolfcrypt/src/pkcs7.c | 117 ++++++++++++++++++++++--------------------
 1 file changed, 62 insertions(+), 55 deletions(-)

diff --git a/wolfcrypt/src/pkcs7.c b/wolfcrypt/src/pkcs7.c
index 12494d970..9142d7eb1 100644
--- a/wolfcrypt/src/pkcs7.c
+++ b/wolfcrypt/src/pkcs7.c
@@ -84,6 +84,7 @@ struct PKCS7State {
     word32 varOne;
     int    varTwo;
     int    varThree;
+    int    varFour;
 
     word32 vers;
     word32 idx;      /* index read into current input buffer */
@@ -373,23 +374,25 @@ static long wc_PKCS7_GetMaxStream(PKCS7* pkcs7, byte flag, byte* in,
 
 /* setter function for stored variables */
 static void wc_PKCS7_StreamStoreVar(PKCS7* pkcs7, word32 var1, int var2,
-        int var3)
+        int var3, int var4)
 {
     if (pkcs7 != NULL && pkcs7->stream != NULL) {
         pkcs7->stream->varOne   = var1;
         pkcs7->stream->varTwo   = var2;
         pkcs7->stream->varThree = var3;
+        pkcs7->stream->varFour  = var4;
     }
 }
 
 /* getter function for stored variables */
 static void wc_PKCS7_StreamGetVar(PKCS7* pkcs7, word32* var1, int* var2,
-        int* var3)
+        int* var3, int* var4)
 {
     if (pkcs7 != NULL && pkcs7->stream != NULL) {
         if (var1 != NULL) *var1 = pkcs7->stream->varOne;
         if (var2 != NULL) *var2 = pkcs7->stream->varTwo;
         if (var3 != NULL) *var3 = pkcs7->stream->varThree;
+        if (var4 != NULL) *var4 = pkcs7->stream->varFour;
     }
 }
 
@@ -4286,7 +4289,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if (pkiMsg2 && pkiMsg2Sz > 0) {
                 pkcs7->stream->maxLen += pkiMsg2Sz + pkcs7->contentSz;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, totalSz, 0, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, totalSz, 0, 0, 0);
         #endif
 
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_VERIFY_STAGE2);
@@ -4300,7 +4303,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 break;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &totalSz, 0, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, &totalSz, 0, 0, 0);
             if (pkcs7->stream->length > 0)
                 pkiMsgSz = pkcs7->stream->length;
         #ifdef ASN_BER_TO_DER
@@ -4458,7 +4461,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &stateIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, localIdx, length);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, localIdx, length, 0);
 
             /* content length is in multiple parts */
             if (multiPart) {
@@ -4489,7 +4492,8 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             else
         #endif
                 pkiMsgSz = (word32)rc;
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, (int*)&localIdx, &length);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, (int*)&localIdx,
+                                  &length, 0);
 
             if (pkcs7->stream->length > 0) {
                 localIdx = 0;
@@ -4649,7 +4653,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &stateIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length, 0);
             if (length > 0) {
                 pkcs7->stream->expected = length;
             }
@@ -4672,7 +4676,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 break;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length, 0);
             if (pkcs7->stream->flagOne) {
                 pkiMsg2 = pkiMsg;
             }
@@ -4851,8 +4855,8 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 pkcs7->stream->expected = (pkcs7->stream->maxLen -
                                 pkcs7->stream->totalRd) + pkcs7->stream->length;
 
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz,  0, 0);
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz,  0, 0, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length, 0);
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_VERIFY_STAGE5);
             FALL_THROUGH;
@@ -4863,7 +4867,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                             pkcs7->stream->expected, &pkiMsg, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length, 0);
             if (pkcs7->stream->flagOne) {
                 pkiMsg2 = pkiMsg;
             }
@@ -4914,7 +4918,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &stateIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length, 0);
 
             if (in2 && in2Sz > 0 && hashBuf && hashSz > 0) {
                 if (length > 0) {
@@ -4941,7 +4945,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 break;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length, 0);
             if (pkcs7->stream->flagOne) {
                 pkiMsg2 = pkiMsg;
             }
@@ -8022,7 +8026,7 @@ static int wc_PKCS7_DecryptKtri(PKCS7* pkcs7, byte* in, word32 inSz,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, idx)) != 0) {
                     break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, 0, sidType, version);
+            wc_PKCS7_StreamStoreVar(pkcs7, 0, sidType, version, 0);
 
             /* @TODO getting total amount left because of GetInt call later on
              * this could be optimized to stream better */
@@ -8048,7 +8052,7 @@ static int wc_PKCS7_DecryptKtri(PKCS7* pkcs7, byte* in, word32 inSz,
             }
             pkiMsgSz = (word32)rc;
 
-            wc_PKCS7_StreamGetVar(pkcs7, NULL, &sidType, &version);
+            wc_PKCS7_StreamGetVar(pkcs7, NULL, &sidType, &version, 0);
 
             /* @TODO get expected size for next part, does not account for
              * GetInt call well */
@@ -8165,7 +8169,7 @@ static int wc_PKCS7_DecryptKtri(PKCS7* pkcs7, byte* in, word32 inSz,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, idx)) != 0) {
                     break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, encryptedKeySz, sidType, version);
+            wc_PKCS7_StreamStoreVar(pkcs7, encryptedKeySz, sidType, version, 0);
             pkcs7->stream->expected = encryptedKeySz;
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_DECRYPT_KTRI_3);
@@ -10212,7 +10216,7 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, length);
+            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, length, 0);
             pkcs7->stream->contentSz = blockKeySz;
             pkcs7->stream->expected = length + MAX_LENGTH_SZ + MAX_LENGTH_SZ +
                 ASN_TAG_SZ + ASN_TAG_SZ;
@@ -10236,7 +10240,7 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
             }
             pkiMsgSz = (word32)rc;
 
-            wc_PKCS7_StreamGetVar(pkcs7, 0, 0, &length);
+            wc_PKCS7_StreamGetVar(pkcs7, 0, 0, &length, 0);
             tmpIv = pkcs7->stream->tmpIv;
             if (tmpIv == NULL) {
                 /* check added to help out static analysis tool */
@@ -10269,7 +10273,42 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
                 ret = ASN_PARSE_E;
             }
 
-            if (ret == 0 && explicitOctet) {
+            if (ret != 0)
+                break;
+
+        #ifndef NO_PKCS7_STREAM
+            if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, &idx)) != 0) {
+                break;
+            }
+            pkcs7->stream->expected = encryptedContentTotalSz;
+            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, 0, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, explicitOctet,
+                                    encryptedContentTotalSz);
+        #endif
+            wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_ENV_5);
+            FALL_THROUGH;
+
+        case WC_PKCS7_ENV_5:
+
+        #ifndef NO_PKCS7_STREAM
+            if ((ret = wc_PKCS7_AddDataToStream(pkcs7, in, inSz,
+                            pkcs7->stream->expected, &pkiMsg, &idx)) != 0) {
+                return ret;
+            }
+
+            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, &explicitOctet,
+                                  &encryptedContentTotalSz);
+            tmpIv = pkcs7->stream->tmpIv;
+
+            /* restore decrypted key */
+            decryptedKey   = pkcs7->stream->aad;
+            decryptedKeySz = pkcs7->stream->aadSz;
+            blockKeySz = pkcs7->stream->contentSz;
+        #else
+            ret = 0;
+        #endif
+
+            if (explicitOctet) {
                 /* encrypted content may be fragmented into multiple
                  * consecutive OCTET STRINGs, if so loop through
                  * collecting and caching encrypted content bytes */
@@ -10311,39 +10350,6 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
                 idx += encryptedContentTotalSz;
             }
 
-            if (ret != 0)
-                break;
-
-        #ifndef NO_PKCS7_STREAM
-            if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, &idx)) != 0) {
-                break;
-            }
-            pkcs7->stream->expected = 0;
-            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, 0);
-            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, 0);
-        #endif
-            wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_ENV_5);
-            FALL_THROUGH;
-
-        case WC_PKCS7_ENV_5:
-
-        #ifndef NO_PKCS7_STREAM
-            if ((ret = wc_PKCS7_AddDataToStream(pkcs7, in, inSz,
-                            pkcs7->stream->expected, &pkiMsg, &idx)) != 0) {
-                return ret;
-            }
-
-            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, NULL);
-            tmpIv = pkcs7->stream->tmpIv;
-
-            /* restore decrypted key */
-            decryptedKey   = pkcs7->stream->aad;
-            decryptedKeySz = pkcs7->stream->aadSz;
-            blockKeySz = pkcs7->stream->contentSz;
-        #else
-            ret = 0;
-        #endif
-
             /* use cached content */
             encryptedContent = pkcs7->cachedEncryptedContent;
             encryptedContentSz = pkcs7->cachedEncryptedContentSz;
@@ -11108,7 +11114,7 @@ WOLFSSL_API int wc_PKCS7_DecodeAuthEnvelopedData(PKCS7* pkcs7, byte* in,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, encOID, blockKeySz, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, encOID, blockKeySz, 0, 0);
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_AUTHENV_4);
             FALL_THROUGH;
@@ -11211,7 +11217,7 @@ WOLFSSL_API int wc_PKCS7_DecodeAuthEnvelopedData(PKCS7* pkcs7, byte* in,
 
             pkcs7->stream->expected = encryptedContentSz;
             wc_PKCS7_StreamStoreVar(pkcs7, encOID, blockKeySz,
-                    encryptedContentSz);
+                    encryptedContentSz, 0);
         #endif
 
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_AUTHENV_5);
@@ -11456,7 +11462,8 @@ authenv_atrbend:
                 encodedAttribs  = pkcs7->stream->aad;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &blockKeySz, &encryptedContentSz);
+            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &blockKeySz,
+                                  &encryptedContentSz, 0);
             encryptedContent   = pkcs7->stream->bufferPt;
         #ifdef WOLFSSL_SMALL_STACK
             decryptedKey = pkcs7->stream->key;

From d8eeefb4b7394fd43cd70d8b645ee698c8108e3b Mon Sep 17 00:00:00 2001
From: Chris Conlon <chris@wolfssl.com>
Date: Mon, 2 Mar 2020 09:13:11 -0700
Subject: [PATCH 3/5] initialize explicitOctet to 0 in
 pwc_PKCS7_DecodeEnvelopedData()

---
 wolfcrypt/src/pkcs7.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wolfcrypt/src/pkcs7.c b/wolfcrypt/src/pkcs7.c
index 9142d7eb1..54c2eae18 100644
--- a/wolfcrypt/src/pkcs7.c
+++ b/wolfcrypt/src/pkcs7.c
@@ -10057,7 +10057,7 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
     int encryptedContentSz = 0;
     byte padLen;
     byte* encryptedContent = NULL;
-    int explicitOctet;
+    int explicitOctet = 0;
     word32 localIdx;
     byte   tag;
 

From 44d2fc55e6bc4adcd1241146f396ff5600d4811f Mon Sep 17 00:00:00 2001
From: Chris Conlon <chris@wolfssl.com>
Date: Tue, 3 Mar 2020 10:27:22 -0700
Subject: [PATCH 4/5] scan-build fixes for wc_PKCS7_DecodeEnvelopedData()

---
 wolfcrypt/src/pkcs7.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/wolfcrypt/src/pkcs7.c b/wolfcrypt/src/pkcs7.c
index 54c2eae18..27fa23a60 100644
--- a/wolfcrypt/src/pkcs7.c
+++ b/wolfcrypt/src/pkcs7.c
@@ -10317,22 +10317,22 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
 
                     if (GetASNTag(pkiMsg, &idx, &tag, pkiMsgSz) < 0) {
                         ret = ASN_PARSE_E;
-                        break;
                     }
 
-                    if (tag != ASN_OCTET_STRING) {
+                    if (ret == 0 && (tag != ASN_OCTET_STRING)) {
                         ret = ASN_PARSE_E;
-                        break;
                     }
 
                     if (ret == 0 && GetLength(pkiMsg, &idx,
                                 &encryptedContentSz, pkiMsgSz) <= 0) {
                         ret = ASN_PARSE_E;
-                        break;
                     }
 
-                    ret = PKCS7_CacheEncryptedContent(pkcs7, &pkiMsg[idx],
-                                                      encryptedContentSz);
+                    if (ret == 0) {
+                        ret = PKCS7_CacheEncryptedContent(pkcs7, &pkiMsg[idx],
+                                                          encryptedContentSz);
+                    }
+
                     if (ret != 0) {
                         break;
                     }
@@ -10340,6 +10340,11 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
                     /* advance idx past encrypted content */
                     idx += encryptedContentSz;
                 }
+
+                if (ret != 0) {
+                    break;
+                }
+
             } else {
                 /* cache encrypted content, no OCTET STRING */
                 ret = PKCS7_CacheEncryptedContent(pkcs7, &pkiMsg[idx],

From 4ad8a2bacb1a7e0914c57f9967aa2fece2000cfc Mon Sep 17 00:00:00 2001
From: Chris Conlon <chris@wolfssl.com>
Date: Fri, 6 Mar 2020 10:50:00 -0700
Subject: [PATCH 5/5] store wc_PKCS7_DecodeEnvelopedData
 encryptedContentTotalSz in existing variable instead of adding another

---
 wolfcrypt/src/pkcs7.c | 55 ++++++++++++++++++++-----------------------
 1 file changed, 25 insertions(+), 30 deletions(-)

diff --git a/wolfcrypt/src/pkcs7.c b/wolfcrypt/src/pkcs7.c
index 27fa23a60..dbebf2534 100644
--- a/wolfcrypt/src/pkcs7.c
+++ b/wolfcrypt/src/pkcs7.c
@@ -84,7 +84,6 @@ struct PKCS7State {
     word32 varOne;
     int    varTwo;
     int    varThree;
-    int    varFour;
 
     word32 vers;
     word32 idx;      /* index read into current input buffer */
@@ -374,25 +373,23 @@ static long wc_PKCS7_GetMaxStream(PKCS7* pkcs7, byte flag, byte* in,
 
 /* setter function for stored variables */
 static void wc_PKCS7_StreamStoreVar(PKCS7* pkcs7, word32 var1, int var2,
-        int var3, int var4)
+        int var3)
 {
     if (pkcs7 != NULL && pkcs7->stream != NULL) {
         pkcs7->stream->varOne   = var1;
         pkcs7->stream->varTwo   = var2;
         pkcs7->stream->varThree = var3;
-        pkcs7->stream->varFour  = var4;
     }
 }
 
 /* getter function for stored variables */
 static void wc_PKCS7_StreamGetVar(PKCS7* pkcs7, word32* var1, int* var2,
-        int* var3, int* var4)
+        int* var3)
 {
     if (pkcs7 != NULL && pkcs7->stream != NULL) {
         if (var1 != NULL) *var1 = pkcs7->stream->varOne;
         if (var2 != NULL) *var2 = pkcs7->stream->varTwo;
         if (var3 != NULL) *var3 = pkcs7->stream->varThree;
-        if (var4 != NULL) *var4 = pkcs7->stream->varFour;
     }
 }
 
@@ -4289,7 +4286,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if (pkiMsg2 && pkiMsg2Sz > 0) {
                 pkcs7->stream->maxLen += pkiMsg2Sz + pkcs7->contentSz;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, totalSz, 0, 0, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, totalSz, 0, 0);
         #endif
 
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_VERIFY_STAGE2);
@@ -4303,7 +4300,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 break;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &totalSz, 0, 0, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, &totalSz, 0, 0);
             if (pkcs7->stream->length > 0)
                 pkiMsgSz = pkcs7->stream->length;
         #ifdef ASN_BER_TO_DER
@@ -4461,7 +4458,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &stateIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, localIdx, length, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, localIdx, length);
 
             /* content length is in multiple parts */
             if (multiPart) {
@@ -4492,8 +4489,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             else
         #endif
                 pkiMsgSz = (word32)rc;
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, (int*)&localIdx,
-                                  &length, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, (int*)&localIdx, &length);
 
             if (pkcs7->stream->length > 0) {
                 localIdx = 0;
@@ -4653,7 +4649,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &stateIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length);
             if (length > 0) {
                 pkcs7->stream->expected = length;
             }
@@ -4676,7 +4672,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 break;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length);
             if (pkcs7->stream->flagOne) {
                 pkiMsg2 = pkiMsg;
             }
@@ -4855,8 +4851,8 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 pkcs7->stream->expected = (pkcs7->stream->maxLen -
                                 pkcs7->stream->totalRd) + pkcs7->stream->length;
 
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz,  0, 0, 0);
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz,  0, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length);
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_VERIFY_STAGE5);
             FALL_THROUGH;
@@ -4867,7 +4863,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                             pkcs7->stream->expected, &pkiMsg, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length);
             if (pkcs7->stream->flagOne) {
                 pkiMsg2 = pkiMsg;
             }
@@ -4918,7 +4914,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &stateIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, pkiMsg2Sz, 0, length);
 
             if (in2 && in2Sz > 0 && hashBuf && hashSz > 0) {
                 if (length > 0) {
@@ -4945,7 +4941,7 @@ static int PKCS7_VerifySignedData(PKCS7* pkcs7, const byte* hashBuf,
                 break;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, &pkiMsg2Sz, 0, &length);
             if (pkcs7->stream->flagOne) {
                 pkiMsg2 = pkiMsg;
             }
@@ -8026,7 +8022,7 @@ static int wc_PKCS7_DecryptKtri(PKCS7* pkcs7, byte* in, word32 inSz,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, idx)) != 0) {
                     break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, 0, sidType, version, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, 0, sidType, version);
 
             /* @TODO getting total amount left because of GetInt call later on
              * this could be optimized to stream better */
@@ -8052,7 +8048,7 @@ static int wc_PKCS7_DecryptKtri(PKCS7* pkcs7, byte* in, word32 inSz,
             }
             pkiMsgSz = (word32)rc;
 
-            wc_PKCS7_StreamGetVar(pkcs7, NULL, &sidType, &version, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, NULL, &sidType, &version);
 
             /* @TODO get expected size for next part, does not account for
              * GetInt call well */
@@ -8169,7 +8165,7 @@ static int wc_PKCS7_DecryptKtri(PKCS7* pkcs7, byte* in, word32 inSz,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, idx)) != 0) {
                     break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, encryptedKeySz, sidType, version, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, encryptedKeySz, sidType, version);
             pkcs7->stream->expected = encryptedKeySz;
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_DECRYPT_KTRI_3);
@@ -10216,7 +10212,7 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, length, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, length);
             pkcs7->stream->contentSz = blockKeySz;
             pkcs7->stream->expected = length + MAX_LENGTH_SZ + MAX_LENGTH_SZ +
                 ASN_TAG_SZ + ASN_TAG_SZ;
@@ -10240,7 +10236,7 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
             }
             pkiMsgSz = (word32)rc;
 
-            wc_PKCS7_StreamGetVar(pkcs7, 0, 0, &length, 0);
+            wc_PKCS7_StreamGetVar(pkcs7, 0, 0, &length);
             tmpIv = pkcs7->stream->tmpIv;
             if (tmpIv == NULL) {
                 /* check added to help out static analysis tool */
@@ -10281,9 +10277,8 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
                 break;
             }
             pkcs7->stream->expected = encryptedContentTotalSz;
-            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, 0, 0);
-            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, explicitOctet,
-                                    encryptedContentTotalSz);
+            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, encOID, expBlockSz, explicitOctet);
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_ENV_5);
             FALL_THROUGH;
@@ -10296,9 +10291,9 @@ WOLFSSL_API int wc_PKCS7_DecodeEnvelopedData(PKCS7* pkcs7, byte* in,
                 return ret;
             }
 
-            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, &explicitOctet,
-                                  &encryptedContentTotalSz);
+            wc_PKCS7_StreamGetVar(pkcs7, &encOID, &expBlockSz, &explicitOctet);
             tmpIv = pkcs7->stream->tmpIv;
+            encryptedContentTotalSz = pkcs7->stream->expected;
 
             /* restore decrypted key */
             decryptedKey   = pkcs7->stream->aad;
@@ -11119,7 +11114,7 @@ WOLFSSL_API int wc_PKCS7_DecodeAuthEnvelopedData(PKCS7* pkcs7, byte* in,
             if ((ret = wc_PKCS7_StreamEndCase(pkcs7, &tmpIdx, &idx)) != 0) {
                 break;
             }
-            wc_PKCS7_StreamStoreVar(pkcs7, encOID, blockKeySz, 0, 0);
+            wc_PKCS7_StreamStoreVar(pkcs7, encOID, blockKeySz, 0);
         #endif
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_AUTHENV_4);
             FALL_THROUGH;
@@ -11222,7 +11217,7 @@ WOLFSSL_API int wc_PKCS7_DecodeAuthEnvelopedData(PKCS7* pkcs7, byte* in,
 
             pkcs7->stream->expected = encryptedContentSz;
             wc_PKCS7_StreamStoreVar(pkcs7, encOID, blockKeySz,
-                    encryptedContentSz, 0);
+                    encryptedContentSz);
         #endif
 
             wc_PKCS7_ChangeState(pkcs7, WC_PKCS7_AUTHENV_5);
@@ -11468,7 +11463,7 @@ authenv_atrbend:
             }
 
             wc_PKCS7_StreamGetVar(pkcs7, &encOID, &blockKeySz,
-                                  &encryptedContentSz, 0);
+                                  &encryptedContentSz);
             encryptedContent   = pkcs7->stream->bufferPt;
         #ifdef WOLFSSL_SMALL_STACK
             decryptedKey = pkcs7->stream->key;