From d1ffe46c04e87a297fed50ba0ff79213cdee7a5e Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Mon, 4 Nov 2019 14:41:10 -0500
Subject: AES_PDF: move CBC logic from pipeline to AES_PDF implementation

---
 libqpdf/AES_PDF_native.cc | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

(limited to 'libqpdf/AES_PDF_native.cc')

diff --git a/libqpdf/AES_PDF_native.cc b/libqpdf/AES_PDF_native.cc
index d6907ee3..697b3a37 100644
--- a/libqpdf/AES_PDF_native.cc
+++ b/libqpdf/AES_PDF_native.cc
@@ -7,10 +7,14 @@
 #include <qpdf/QIntC.hh>
 #include <string>
 #include <stdlib.h>
+#include <qpdf/QPDFCryptoImpl.hh>
 
 AES_PDF_native::AES_PDF_native(bool encrypt, unsigned char const* key,
-                               size_t key_bytes) :
+                               size_t key_bytes, bool cbc_mode,
+                               unsigned char* cbc_block) :
     encrypt(encrypt),
+    cbc_mode(cbc_mode),
+    cbc_block(cbc_block),
     nrounds(0)
 {
     size_t keybits = 8 * key_bytes;
@@ -44,12 +48,33 @@ AES_PDF_native::update(unsigned char* in_data, unsigned char* out_data)
 {
     if (this->encrypt)
     {
+	if (this->cbc_mode)
+	{
+	    for (size_t i = 0; i < QPDFCryptoImpl::rijndael_buf_size; ++i)
+	    {
+		in_data[i] ^= this->cbc_block[i];
+	    }
+	}
 	rijndaelEncrypt(this->rk.get(),
                         this->nrounds, in_data, out_data);
+	if (this->cbc_mode)
+	{
+	    memcpy(this->cbc_block, out_data,
+                   QPDFCryptoImpl::rijndael_buf_size);
+	}
     }
     else
     {
 	rijndaelDecrypt(this->rk.get(),
                         this->nrounds, in_data, out_data);
+	if (this->cbc_mode)
+	{
+	    for (size_t i = 0; i < QPDFCryptoImpl::rijndael_buf_size; ++i)
+	    {
+		out_data[i] ^= this->cbc_block[i];
+	    }
+	    memcpy(this->cbc_block, in_data,
+                   QPDFCryptoImpl::rijndael_buf_size);
+	}
     }
 }
-- 
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