Add flag to avoid continuous
[openssl.git] / crypto / evp / digest.c
index b22eed4..0623ddf 100644 (file)
@@ -248,6 +248,7 @@ int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in)
 
 int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
        {
+       unsigned char *tmp_buf;
        if ((in == NULL) || (in->digest == NULL))
                {
                EVPerr(EVP_F_EVP_MD_CTX_COPY,EVP_R_INPUT_NOT_INITIALIZED);
@@ -262,15 +263,22 @@ int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
                }
 #endif
 
+       if (out->digest == in->digest)
+               {
+               tmp_buf = out->md_data;
+               EVP_MD_CTX_set_flags(out,EVP_MD_CTX_FLAG_REUSE);
+               }
+       else tmp_buf = NULL;
        EVP_MD_CTX_cleanup(out);
        memcpy(out,in,sizeof *out);
 
        if (out->digest->ctx_size)
                {
-               out->md_data=OPENSSL_malloc(out->digest->ctx_size);
+               if (tmp_buf) out->md_data = tmp_buf;
+               else out->md_data=OPENSSL_malloc(out->digest->ctx_size);
                memcpy(out->md_data,in->md_data,out->digest->ctx_size);
                }
-       
+
        if (out->digest->copy)
                return out->digest->copy(out,in);
        
@@ -308,7 +316,8 @@ int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx)
        if (ctx->digest && ctx->digest->cleanup
            && !EVP_MD_CTX_test_flags(ctx,EVP_MD_CTX_FLAG_CLEANED))
                ctx->digest->cleanup(ctx);
-       if (ctx->digest && ctx->digest->ctx_size && ctx->md_data)
+       if (ctx->digest && ctx->digest->ctx_size && ctx->md_data
+           && !EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_REUSE))
                {
                OPENSSL_cleanse(ctx->md_data,ctx->digest->ctx_size);
                OPENSSL_free(ctx->md_data);