pad[i] = 0x36 ^ ctx->key[i];
if (!EVP_DigestInit_ex(ctx->i_ctx, md, impl)
|| !EVP_DigestUpdate(ctx->i_ctx, pad, EVP_MD_block_size(md)))
goto err;
pad[i] = 0x36 ^ ctx->key[i];
if (!EVP_DigestInit_ex(ctx->i_ctx, md, impl)
|| !EVP_DigestUpdate(ctx->i_ctx, pad, EVP_MD_block_size(md)))
goto err;