Make (stream|block)(Encode|Decode) return false

encfs/BlockNameIO.cpp

@@ -155,8 +155,11 @@ int BlockNameIO::encodeName(const char *plaintextName, int length, uint64_t *iv,
   encodedName[0] = (mac >> 8) & 0xff;
   encodedName[1] = (mac)&0xff;
 
-  _cipher->blockEncode((unsigned char *)encodedName + 2, length + padding,
+  bool ok;
-                       (uint64_t)mac ^ tmpIV, _key);
+  ok = _cipher->blockEncode((unsigned char *)encodedName + 2, length + padding,
+                            (uint64_t)mac ^ tmpIV, _key);
+  if (!ok)
+    throw Error("block encode failed in filename encode");
 
   // convert to base 64 ascii
   int encodedStreamLen = length + 2 + padding;
@@ -209,8 +212,11 @@ int BlockNameIO::decodeName(const char *encodedName, int length, uint64_t *iv,
   uint64_t tmpIV = 0;
   if (iv && _interface >= 3) tmpIV = *iv;
 
-  _cipher->blockDecode((unsigned char *)tmpBuf + 2, decodedStreamLen,
+  bool ok;
-                       (uint64_t)mac ^ tmpIV, _key);
+  ok = _cipher->blockDecode((unsigned char *)tmpBuf + 2, decodedStreamLen,
+                            (uint64_t)mac ^ tmpIV, _key);
+  if (!ok)
+    throw Error("block decode failed in filename decode");
 
   // find out true string length
   int padding = (unsigned char)tmpBuf[2 + decodedStreamLen - 1];

encfs/CipherFileIO.cpp

@@ -186,7 +186,8 @@ int CipherFileIO::initHeader() {
     req.dataLen = 8;
     base->read(req);
 
-    cipher->streamDecode(buf, sizeof(buf), externalIV, key);
+    if(!cipher->streamDecode(buf, sizeof(buf), externalIV, key))
+      return -EBADMSG;
 
     fileIV = 0;
     for (int i = 0; i < 8; ++i) fileIV = (fileIV << 8) | (uint64_t)buf[i];
@@ -210,7 +211,8 @@ int CipherFileIO::initHeader() {
     } while (fileIV == 0);  // don't accept 0 as an option..
 
     if (base->isWritable()) {
-      cipher->streamEncode(buf, sizeof(buf), externalIV, key);
+      if(!cipher->streamEncode(buf, sizeof(buf), externalIV, key))
+        return -EBADMSG;
 
       IORequest req;
       req.offset = 0;
@@ -247,7 +249,8 @@ bool CipherFileIO::writeHeader() {
     fileIV >>= 8;
   }
 
-  cipher->streamEncode(buf, sizeof(buf), externalIV, key);
+  if(!cipher->streamEncode(buf, sizeof(buf), externalIV, key))
+    return false;
 
   IORequest req;
   req.offset = 0;
@@ -271,7 +274,7 @@ bool CipherFileIO::writeHeader() {
  * the IV. This guarantees unpredictability and prevents watermarking
  * attacks.
  */
-void CipherFileIO::generateReverseHeader(unsigned char *headerBuf) {
+int CipherFileIO::generateReverseHeader(unsigned char *headerBuf) {
 
   struct stat stbuf;
   int res = getAttr(&stbuf);
@@ -305,7 +308,9 @@ void CipherFileIO::generateReverseHeader(unsigned char *headerBuf) {
   VLOG(1) << "fileIV=" << fileIV;
 
   // Encrypt externally-visible header
-  cipher->streamEncode(headerBuf, HEADER_SIZE, externalIV, key);
+  if(!cipher->streamEncode(headerBuf, HEADER_SIZE, externalIV, key))
+    return -EBADMSG;
+  return 0;
 }
 
 /**
@@ -481,7 +486,9 @@ ssize_t CipherFileIO::read(const IORequest &origReq) const {
   // generate the file IV header
   // this is needed in any case - without IV the file cannot be decoded
   unsigned char headerBuf[HEADER_SIZE];
-  const_cast<CipherFileIO *>(this)->generateReverseHeader(headerBuf);
+  int res = const_cast<CipherFileIO *>(this)->generateReverseHeader(headerBuf);
+  if (res < 0)
+    return res;
 
   // Copy the request so we can modify it without affecting the caller
   IORequest req = origReq;

encfs/CipherFileIO.h

@@ -66,7 +66,7 @@ class CipherFileIO : public BlockFileIO {
  private:
   virtual ssize_t readOneBlock(const IORequest &req) const;
   virtual int writeOneBlock(const IORequest &req);
-  virtual void generateReverseHeader(unsigned char *data);
+  virtual int generateReverseHeader(unsigned char *data);
 
   int initHeader();
   bool writeHeader();

encfs/SSL_Cipher.cpp

@@ -748,6 +748,7 @@ bool SSL_Cipher::streamEncode(unsigned char *buf, int size, uint64_t iv64,
   if (dstLen != size) {
     RLOG(ERROR) << "encoding " << size << " bytes, got back " << dstLen << " ("
                 << tmpLen << " in final_ex)";
+    return false;
   }
 
   return true;
@@ -784,6 +785,7 @@ bool SSL_Cipher::streamDecode(unsigned char *buf, int size, uint64_t iv64,
   if (dstLen != size) {
     RLOG(ERROR) << "decoding " << size << " bytes, got back " << dstLen << " ("
                 << tmpLen << " in final_ex)";
+    return false;
   }
 
   return true;
@@ -798,8 +800,10 @@ bool SSL_Cipher::blockEncode(unsigned char *buf, int size, uint64_t iv64,
 
   // data must be integer number of blocks
   const int blockMod = size % EVP_CIPHER_CTX_block_size(key->block_enc);
-  if (blockMod != 0)
+  if (blockMod != 0) {
-    throw Error("Invalid data size, not multiple of block size");
+    RLOG(ERROR) << "Invalid data size, not multiple of block size";
+    return false;
+  }
 
   Lock lock(key->mutex);
 
@@ -816,6 +820,7 @@ bool SSL_Cipher::blockEncode(unsigned char *buf, int size, uint64_t iv64,
   if (dstLen != size) {
     RLOG(ERROR) << "encoding " << size << " bytes, got back " << dstLen << " ("
                 << tmpLen << " in final_ex)";
+    return false;
   }
 
   return true;
@@ -830,8 +835,10 @@ bool SSL_Cipher::blockDecode(unsigned char *buf, int size, uint64_t iv64,
 
   // data must be integer number of blocks
   const int blockMod = size % EVP_CIPHER_CTX_block_size(key->block_dec);
-  if (blockMod != 0)
+  if (blockMod != 0) {
-    throw Error("Invalid data size, not multiple of block size");
+    RLOG(ERROR) << "Invalid data size, not multiple of block size";
+    return false;
+  }
 
   Lock lock(key->mutex);
 
@@ -848,6 +855,7 @@ bool SSL_Cipher::blockDecode(unsigned char *buf, int size, uint64_t iv64,
   if (dstLen != size) {
     RLOG(ERROR) << "decoding " << size << " bytes, got back " << dstLen << " ("
                 << tmpLen << " in final_ex)";
+    return false;
   }
 
   return true;