A better compromise between encrypt and decrypt (but why isn't it as fast
authorBen Laurie <ben@openssl.org>
Mon, 9 Jul 2001 21:00:36 +0000 (21:00 +0000)
committerBen Laurie <ben@openssl.org>
Mon, 9 Jul 2001 21:00:36 +0000 (21:00 +0000)
for encrypt?).

CHANGES
crypto/evp/evp.h
crypto/evp/evp_enc.c

diff --git a/CHANGES b/CHANGES
index 78a894d443f8935593fc07467505406783224855..e7d773f8627e065f60a9aa712533e94834c615a2 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -24,9 +24,9 @@ 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
+des-cbc           4660.16k     5650.19k     5807.19k     5827.13k     5783.32k
 decrypt
-des-cbc           3615.18k     5102.53k     5501.58k     5631.13k     5635.52k
+des-cbc           3624.96k     5258.21k     5530.91k     5624.30k     5628.26k
      [Ben Laurie]
 
   *) Fix crypto/bn/asm/mips3.s.
index ecd221fb06af5439a46107634f44228159c2b968..04cb709c8fe312242354734f6fdbb8ad7bee53a4 100644 (file)
@@ -455,6 +455,9 @@ struct evp_cipher_ctx_st
                RIJNDAEL_KEY rijndael;
 #endif
                } c;
+       int final_used;
+       int block_mask;
+       unsigned char final[EVP_MAX_BLOCK_LENGTH];/* possible final block */
        };
 
 typedef struct evp_Encode_Ctx_st
index d723d095c180f5da480c69ad194f5b0917ed2e39..9a7a553bef292ebfc368da55918639c064294ee0 100644 (file)
@@ -125,6 +125,8 @@ int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
        }
        if(enc != -1) ctx->encrypt=enc;
        ctx->buf_len=0;
+       ctx->final_used=0;
+       ctx->block_mask=ctx->cipher->block_size-1;
        return 1;
        }
 
@@ -160,14 +162,7 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
        {
        int i,j,bl;
 
-       i=ctx->buf_len;
-       bl=ctx->cipher->block_size;
-       if ((inl == 0) && (i != bl))
-               {
-               *outl=0;
-               return 1;
-               }
-       if(i == 0 && (inl&(bl-1)) == 0)
+       if(ctx->buf_len == 0 && (inl&(ctx->block_mask)) == 0)
                {
                if(ctx->cipher->do_cipher(ctx,out,in,inl))
                        {
@@ -180,24 +175,26 @@ int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                        return 0;
                        }
                }
-       *outl=0;
+       i=ctx->buf_len;
+       bl=ctx->cipher->block_size;
        if (i != 0)
                {
                if (i+inl < bl)
                        {
                        memcpy(&(ctx->buf[i]),in,inl);
                        ctx->buf_len+=inl;
+                       *outl=0;
                        return 1;
                        }
                else
                        {
                        j=bl-i;
-                       if (j != 0) memcpy(&(ctx->buf[i]),in,j);
+                       memcpy(&(ctx->buf[i]),in,j);
                        if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
                        inl-=j;
                        in+=j;
                        out+=bl;
-                       *outl+=bl;
+                       *outl=bl;
                        }
                }
        i=inl&(bl-1);
@@ -246,48 +243,42 @@ int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
             unsigned char *in, int inl)
        {
-       int b,bl,n;
-       int keep_last=0;
+       int b;
 
-       *outl=0;
-       if (inl == 0) return 1;
+       if (inl == 0)
+               {
+               *outl=0;
+               return 1;
+               }
 
        if (ctx->flags & EVP_CIPH_NO_PADDING)
                return EVP_EncryptUpdate(ctx, out, outl, in, inl);
 
        b=ctx->cipher->block_size;
-       if (b > 1)
+       if(ctx->final_used)
                {
-               /* Is the input a multiple of the block size? */
-               bl=ctx->buf_len;
-               n=inl+bl;
-               if (n%b == 0)
-                       {
-                       if (inl < b) /* must be 'just one' buff */
-                               {
-                               memcpy(&(ctx->buf[bl]),in,inl);
-                               ctx->buf_len=b;
-                               *outl=0;
-                               return 1;
-                               }
-                       keep_last=1;
-                       inl-=b; /* don't do the last block */
-                       }
+               memcpy(out,ctx->final,b);
+               out+=b;
                }
-       if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0;
+               
+       if(!EVP_EncryptUpdate(ctx,out,outl,in,inl))
+               return 0;
 
        /* if we have 'decrypted' a multiple of block size, make sure
         * we have a copy of this last block */
-       if (keep_last)
+       if (b > 1 && !ctx->buf_len)
                {
-               memcpy(&(ctx->buf[0]),&(in[inl]),b);
-#ifdef DEBUG
-               if (ctx->buf_len != 0)
+               if(!ctx->final_used)
                        {
-                       abort();
+                       *outl-=b;
+                       ctx->final_used=1;
                        }
-#endif
-               ctx->buf_len=b;
+               memcpy(ctx->final,&out[*outl],b);
+               }
+       else if(ctx->final_used)
+               {
+               ctx->final_used=0;
+               *outl+=b;
                }
        return 1;
        }
@@ -311,15 +302,12 @@ int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
                }
        if (b > 1)
                {
-               if (ctx->buf_len != b)
+               if (ctx->buf_len || !ctx->final_used)
                        {
                        EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
                        return(0);
                        }
-               if(!EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0)) return 0;
-               if (n != b)
-                       return(0);
-               n=ctx->buf[b-1];
+               n=ctx->final[b-1];
                if (n > b)
                        {
                        EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
@@ -327,7 +315,7 @@ int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
                        }
                for (i=0; i<n; i++)
                        {
-                       if (ctx->buf[--b] != n)
+                       if (ctx->final[--b] != n)
                                {
                                EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
                                return(0);
@@ -335,7 +323,7 @@ int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
                        }
                n=ctx->cipher->block_size-n;
                for (i=0; i<n; i++)
-                       out[i]=ctx->buf[i];
+                       out[i]=ctx->final[i];
                *outl=n;
                }
        else