From e8236c5fd41f0f64402a43563a7f97aa1fd96a1a Mon Sep 17 00:00:00 2001
From: Keith Winstein <keithw@mit.edu>
Date: Sun, 22 Apr 2012 22:46:49 -0400
Subject: [PATCH] Use AlignedBuffer stedda posix_memalign(). Should work on PPC
 OS X 10.5.

Fixes #233 github issue.
---
 src/crypto/crypto.cc | 10 ++--------
 src/crypto/crypto.h  |  1 +
 src/crypto/ocb.cc    | 23 +----------------------
 3 files changed, 4 insertions(+), 30 deletions(-)

diff --git a/src/crypto/crypto.cc b/src/crypto/crypto.cc
index d7f45c4..71b9fcd 100644
--- a/src/crypto/crypto.cc
+++ b/src/crypto/crypto.cc
@@ -138,13 +138,9 @@ string Base64Key::printable_key( void ) const
 }
 
 Session::Session( Base64Key s_key )
-  : key( s_key ), ctx( NULL ), blocks_encrypted( 0 )
+  : key( s_key ), ctx_buf( ae_ctx_sizeof() ),
+    ctx( (ae_ctx *)ctx_buf.data() ), blocks_encrypted( 0 )
 {
-  ctx = ae_allocate( NULL );
-  if ( ctx == NULL ) {
-    throw CryptoException( "Could not allocate AES-OCB context." );
-  }
-
   if ( AE_SUCCESS != ae_init( ctx, key.data(), 16, 12, 16 ) ) {
     throw CryptoException( "Could not initialize AES-OCB context." );
   }
@@ -155,8 +151,6 @@ Session::~Session()
   if ( ae_clear( ctx ) != AE_SUCCESS ) {
     throw CryptoException( "Could not clear AES-OCB context." );
   }
-
-  ae_free( ctx );
 }
 
 Nonce::Nonce( uint64_t val )
diff --git a/src/crypto/crypto.h b/src/crypto/crypto.h
index 5d7a3af..bbd70b4 100644
--- a/src/crypto/crypto.h
+++ b/src/crypto/crypto.h
@@ -98,6 +98,7 @@ namespace Crypto {
   class Session {
   private:
     Base64Key key;
+    AlignedBuffer ctx_buf;
     ae_ctx *ctx;
     uint64_t blocks_encrypted;
     
diff --git a/src/crypto/ocb.cc b/src/crypto/ocb.cc
index 8176896..1f14fa3 100644
--- a/src/crypto/ocb.cc
+++ b/src/crypto/ocb.cc
@@ -623,28 +623,7 @@ static block getL(const ae_ctx *ctx, unsigned tz)
 /* 32-bit SSE2 and Altivec systems need to be forced to allocate memory
    on 16-byte alignments. (I believe all major 64-bit systems do already.) */
 
-ae_ctx* ae_allocate(void *misc)
-{ 
-	void *p;
-	(void) misc;                     /* misc unused in this implementation */
-	#if (__SSE2__ && !_M_X64 && !_M_AMD64 && !__amd64__)
-    	p = _mm_malloc(sizeof(ae_ctx),16); 
-	#elif (__ALTIVEC__ && !__PPC64__)
-		if (posix_memalign(&p,16,sizeof(ae_ctx)) != 0) p = NULL;
-	#else
-		p = malloc(sizeof(ae_ctx));
-	#endif
-	return (ae_ctx *)p;
-}
-
-void ae_free(ae_ctx *ctx)
-{
-	#if (__SSE2__ && !_M_X64 && !_M_AMD64 && !__amd64__)
-		_mm_free(ctx);
-	#else
-		free(ctx);
-	#endif
-}
+/* Mosh uses its own AlignedBuffer class, not ae_allocate() or ae_free(). */
 
 /* ----------------------------------------------------------------------- */