crypto: prepare for enabling use of unique IV

src/XrdCrypto/XrdCryptoCipher.cc

@@ -145,35 +145,65 @@ bool XrdCryptoCipher::IsDefaultLength() const
 }
 
 //____________________________________________________________________________
-int XrdCryptoCipher::Encrypt(XrdSutBucket &bck)
+int XrdCryptoCipher::MaxIVLength() const
+{
+   // Return the max cipher IV length
+
+   ABSTRACTMETHOD("XrdCryptoCipher::MaxIVLength");
+   return 0;
+}
+
+//____________________________________________________________________________
+int XrdCryptoCipher::Encrypt(XrdSutBucket &bck, bool useiv)
 {
    // Encrypt bucket bck with local cipher
    // Return size of encoded bucket or -1 in case of error
    int snew = -1;
 
-   int sz = EncOutLength(bck.size);
+   int liv = 0;
+   char *iv = 0;
+   if (useiv) {
+      iv = RefreshIV(liv);
+      if (!iv) return snew;
+   }
+
+   int sz = EncOutLength(bck.size) + liv;
    char *newbck = new char[sz];
    if (newbck) {
       memset(newbck, 0, sz);
-      snew = Encrypt(bck.buffer,bck.size,newbck);
+      if (liv > 0) memcpy(newbck, iv, liv);
+      snew = Encrypt(bck.buffer,bck.size,newbck+liv);
       if (snew > -1)
-         bck.Update(newbck,snew);
+         bck.Update(newbck,snew + liv);
    }
    return snew;
 }
 
 //____________________________________________________________________________
-int XrdCryptoCipher::Decrypt(XrdSutBucket &bck)
+int XrdCryptoCipher::Decrypt(XrdSutBucket &bck, bool useiv)
 {
    // Decrypt bucket bck with local cipher
    // Return size of encoded bucket or -1 in case of error
    int snew = -1;
 
-   int sz = DecOutLength(bck.size);
+   int liv = (useiv) ? MaxIVLength() : 0;
+
+   int sz = DecOutLength(bck.size - liv);
    char *newbck = new char[sz];
    if (newbck) {
+
+      if (useiv) {
+         char *iv = new char[liv];
+         if (iv) {
+            memcpy(iv,bck.buffer,liv);
+            SetIV(liv, iv);
+            delete[] iv;
+         } else {
+            return snew;
+         }
+      }
       memset(newbck, 0, sz);
-      snew = Decrypt(bck.buffer,bck.size,newbck);
+      snew = Decrypt(bck.buffer + liv, bck.size - liv, newbck);
       if (snew > -1)
          bck.Update(newbck,snew);
    }

src/XrdCrypto/XrdCryptoCipher.hh

@@ -67,15 +67,16 @@ public:
    virtual char *IV(int &l) const;
    virtual bool IsDefaultLength() const;
    virtual char *Public(int &lpub);
+   virtual int  MaxIVLength() const;
 
    // Additional setters
    virtual void SetIV(int l, const char *iv);
 
    // Additional methods
    virtual int Encrypt(const char *in, int lin, char *out);
    virtual int Decrypt(const char *in, int lin, char *out);
-   int Encrypt(XrdSutBucket &buck);
-   int Decrypt(XrdSutBucket &buck);
+   int Encrypt(XrdSutBucket &buck, bool useiv = true);
+   int Decrypt(XrdSutBucket &buck, bool useiv = true);
    virtual char *RefreshIV(int &l); 
 };
 

src/XrdCrypto/XrdCryptosslCipher.cc

@@ -1005,8 +1005,8 @@ void XrdCryptosslCipher::GenerateIV()
       lIV = 0;
    }
 
-   // Generate a new one
-   fIV = XrdSutRndm::GetBuffer(EVP_MAX_IV_LENGTH);
+   // Generate a new one, using crypt-like chars
+   fIV = XrdSutRndm::GetBuffer(EVP_MAX_IV_LENGTH, 3);
    if (fIV)
       lIV = EVP_MAX_IV_LENGTH;
 }
@@ -1044,6 +1044,8 @@ int XrdCryptosslCipher::EncDec(int enc, const char *in, int lin, char *out)
 
    int lout = 0;
 
+   const char *action = (enc == 1) ? "encrypting" : "decrypting"; 
+
    // Check inputs
    if (!in || lin <= 0 || !out) {
       DEBUG("wrong inputs arguments");
@@ -1088,7 +1090,7 @@ int XrdCryptosslCipher::EncDec(int enc, const char *in, int lin, char *out)
    int ltmp = 0;
    if (!EVP_CipherUpdate(ctx, (unsigned char *)&out[0], &ltmp,
                                (unsigned char *)in, lin)) {
-      DEBUG("error encrypting");
+      DEBUG("error " << action);
       return 0;
    }
    lout = ltmp;
@@ -1119,3 +1121,11 @@ int XrdCryptosslCipher::DecOutLength(int l)
    lout = (lout <= 0) ? l : lout;
    return lout;
 }
+
+//____________________________________________________________________________
+int XrdCryptosslCipher::MaxIVLength() const
+{
+   // Return the max cipher IV length
+
+   return EVP_MAX_IV_LENGTH;
+}

src/XrdCrypto/XrdCryptosslCipher.hh

@@ -90,6 +90,7 @@ public:
    XrdSutBucket *AsBucket();
    char *IV(int &l) const { l = lIV; return fIV; }
    bool IsDefaultLength() const { return deflength; }
+   int  MaxIVLength() const;
 
    // Additional setter
    void  SetIV(int l, const char *iv);