From f31b12503e6de9252d552b35df3e6e0f1f217b68 Mon Sep 17 00:00:00 2001
From: Ben Laurie <ben@openssl.org>
Date: Sun, 8 Jul 2001 17:27:32 +0000
Subject: [PATCH] Use & instead of % - worth about 4% for 8 byte blocks.

---
 CHANGES              | 18 ++++++++++++++++++
 crypto/evp/evp_enc.c | 12 ++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 94acfc5268..78a894d443 100644
--- a/CHANGES
+++ b/CHANGES
@@ -11,6 +11,24 @@
          *) applies to 0.9.6a (/0.9.6b) and 0.9.7
          +) applies to 0.9.7 only
 
+  +) Speed up EVP routines.
+     Before:
+encrypt
+type              8 bytes     64 bytes    256 bytes   1024 bytes   8192 bytes
+des-cbc           4408.85k     5560.51k     5778.46k     5862.20k     5825.16k
+des-cbc           4389.55k     5571.17k     5792.23k     5846.91k     5832.11k
+des-cbc           4394.32k     5575.92k     5807.44k     5848.37k     5841.30k
+decrypt
+des-cbc           3482.66k     5069.49k     5496.39k     5614.16k     5639.28k
+des-cbc           3480.74k     5068.76k     5510.34k     5609.87k     5635.52k
+des-cbc           3483.72k     5067.62k     5504.60k     5708.01k     5724.80k
+     After:
+encrypt
+des-cbc           4581.64k     5666.39k     5811.23k     5871.60k     5833.23k
+decrypt
+des-cbc           3615.18k     5102.53k     5501.58k     5631.13k     5635.52k
+     [Ben Laurie]
+
   *) Fix crypto/bn/asm/mips3.s.
      [Andy Polyakov]
 
diff --git a/crypto/evp/evp_enc.c b/crypto/evp/evp_enc.c
index 14c8506e80..ae1a22ebb8 100644
--- a/crypto/evp/evp_enc.c
+++ b/crypto/evp/evp_enc.c
@@ -62,6 +62,8 @@
 #include <openssl/err.h>
 #include "evp_locl.h"
 
+#include <assert.h>
+
 const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;
 
 void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
@@ -88,6 +90,12 @@ int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 		EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
 		return 0;
 	}
+
+	/* we assume block size is a power of 2 in *cryptUpdate */
+	assert(ctx->cipher->block_size == 1
+	       || ctx->cipher->block_size == 8
+	       || ctx->cipher->block_size == 16);
+
 	if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
 		switch(EVP_CIPHER_CTX_mode(ctx)) {
 
@@ -147,7 +155,6 @@ int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 	return EVP_CipherInit(ctx, cipher, key, iv, 0);
 	}
 
-
 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 	     unsigned char *in, int inl)
 	{
@@ -176,7 +183,8 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 			*outl+=bl;
 			}
 		}
-	i=inl%bl; /* how much is left */
+	//	i=inl%bl; /* how much is left */
+	i=inl&(bl-1);
 	inl-=i;
 	if (inl > 0)
 		{
-- 
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