add CYASSL_GENERAL_ALIGNMENT detection and setting for TLS alignment attempt

cyassl/ctaocrypt/settings.h

@@ -72,13 +72,6 @@
 
 #include <cyassl/ctaocrypt/visibility.h>
 
-/* stream ciphers except arc4 need 32bit alignment, intel ok without */
-#if defined(__x86_64__) || defined(__ia64__) || defined(__i386__)
-    #define NO_XSTREAM_ALIGNMENT
-#else
-    #define XSTREAM_ALIGNMENT
-#endif
-
 #ifdef IPHONE
     #define SIZEOF_LONG_LONG 8
 #endif
@@ -478,6 +471,29 @@
 #endif
 
 
+/* stream ciphers except arc4 need 32bit alignment, intel ok without */
+#if defined(__x86_64__) || defined(__ia64__) || defined(__i386__)
+    #define NO_XSTREAM_ALIGNMENT
+#else
+    #define XSTREAM_ALIGNMENT
+#endif
+
+
+
+/* if using hardware crypto and have alignment requirements, specify the
+   requirement here.  The record header of SSL/TLS will prvent easy alignment.
+   This hint tries to help as much as possible.  Needs to be bigger than
+   record header sz (5) if not 0 */
+#ifndef CYASSL_GENERAL_ALIGNMENT
+    #ifdef CYASSL_AESNI
+        #define CYASSL_GENERAL_ALIGNMENT 16
+    #elif defined(XSTREAM_ALIGNMENT)
+        #define CYASSL_GENERAL_ALIGNMENT  8
+    #else 
+        #define CYASSL_GENERAL_ALIGNMENT  0 
+    #endif
+#endif
+
 /* Place any other flags or defines here */
 
 

cyassl/internal.h

@@ -853,8 +853,9 @@ typedef struct {
     word32 idx;          /* idx to part of length already consumed */
     byte*  buffer;       /* place holder for static or dynamic buffer */
     word32 bufferSize;   /* current buffer size */
-    byte   dynamicFlag;  /* dynamic memory currently in use */
     ALIGN16 byte staticBuffer[STATIC_BUFFER_LEN];
+    byte   dynamicFlag;  /* dynamic memory currently in use */
+    byte   offset;       /* alignment offset attempt */
 } bufferStatic;
 
 /* Cipher Suites holder */

src/internal.c

@@ -1204,11 +1204,13 @@ int InitSSL(CYASSL* ssl, CYASSL_CTX* ctx)
     ssl->buffers.inputBuffer.buffer = ssl->buffers.inputBuffer.staticBuffer;
     ssl->buffers.inputBuffer.bufferSize  = STATIC_BUFFER_LEN;
     ssl->buffers.inputBuffer.dynamicFlag = 0;
+    ssl->buffers.inputBuffer.offset   = 0;
     ssl->buffers.outputBuffer.length  = 0;
     ssl->buffers.outputBuffer.idx     = 0;
     ssl->buffers.outputBuffer.buffer = ssl->buffers.outputBuffer.staticBuffer;
     ssl->buffers.outputBuffer.bufferSize  = STATIC_BUFFER_LEN;
     ssl->buffers.outputBuffer.dynamicFlag = 0;
+    ssl->buffers.outputBuffer.offset      = 0;
     ssl->buffers.domainName.buffer    = 0;
 #ifndef NO_CERTS
     ssl->buffers.serverDH_P.buffer    = 0;
@@ -2288,10 +2290,12 @@ retry:
 void ShrinkOutputBuffer(CYASSL* ssl)
 {
     CYASSL_MSG("Shrinking output buffer\n");
-    XFREE(ssl->buffers.outputBuffer.buffer, ssl->heap, DYNAMIC_TYPE_OUT_BUFFER);
+    XFREE(ssl->buffers.outputBuffer.buffer - ssl->buffers.outputBuffer.offset,
+          ssl->heap, DYNAMIC_TYPE_OUT_BUFFER);
     ssl->buffers.outputBuffer.buffer = ssl->buffers.outputBuffer.staticBuffer;
     ssl->buffers.outputBuffer.bufferSize  = STATIC_BUFFER_LEN;
     ssl->buffers.outputBuffer.dynamicFlag = 0;
+    ssl->buffers.outputBuffer.offset      = 0;
 }
 
 
@@ -2387,11 +2391,24 @@ int SendBuffered(CYASSL* ssl)
 /* Grow the output buffer */
 static INLINE int GrowOutputBuffer(CYASSL* ssl, int size)
 {
-    byte* tmp = (byte*) XMALLOC(size + ssl->buffers.outputBuffer.length,
+    byte* tmp;
-                                ssl->heap, DYNAMIC_TYPE_OUT_BUFFER);
+    byte  align = CYASSL_GENERAL_ALIGNMENT;
+    /* the encrypted data will be offset from the front of the buffer by
+       the record header, if the user wants encrypted alignment they need
+       to define their alignment requirement */
+
+    if (align && align < RECORD_HEADER_SZ) {
+        CYASSL_MSG("CyaSSL alignment requirement is too small");
+        return BAD_ALIGN_E;
+    }
+
+    tmp = (byte*) XMALLOC(size + ssl->buffers.outputBuffer.length + align,
+                          ssl->heap, DYNAMIC_TYPE_OUT_BUFFER);
     CYASSL_MSG("growing output buffer\n");
    
     if (!tmp) return MEMORY_E;
+    if (align)
+        tmp += align - RECORD_HEADER_SZ;
 
     if (ssl->buffers.outputBuffer.length)
         XMEMCPY(tmp, ssl->buffers.outputBuffer.buffer,
@@ -2401,6 +2418,10 @@ static INLINE int GrowOutputBuffer(CYASSL* ssl, int size)
         XFREE(ssl->buffers.outputBuffer.buffer, ssl->heap,
               DYNAMIC_TYPE_OUT_BUFFER);
     ssl->buffers.outputBuffer.dynamicFlag = 1;
+    if (align)
+        ssl->buffers.outputBuffer.offset = align - RECORD_HEADER_SZ;
+    else
+        ssl->buffers.outputBuffer.offset = 0;
     ssl->buffers.outputBuffer.buffer = tmp;
     ssl->buffers.outputBuffer.bufferSize = size +
                                            ssl->buffers.outputBuffer.length;