From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tudor Ambarus Subject: [RFC PATCH v2 3/4] crypto: dh - allow user to provide NULL privkey Date: Wed, 17 May 2017 18:26:52 +0300 Message-ID: <1495034813-27143-4-git-send-email-tudor.ambarus@microchip.com> References: <1495034813-27143-1-git-send-email-tudor.ambarus@microchip.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , , , , Tudor Ambarus To: , Return-path: Received: from esa3.microchip.iphmx.com ([68.232.153.233]:58579 "EHLO esa3.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752156AbdEQP1f (ORCPT ); Wed, 17 May 2017 11:27:35 -0400 In-Reply-To: <1495034813-27143-1-git-send-email-tudor.ambarus@microchip.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: If the user provides a NULL private key, the kernel will generate it and further use it for dh. Signed-off-by: Tudor Ambarus --- crypto/dh.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/crypto/dh.c b/crypto/dh.c index 87e3542..7b4ac5b 100644 --- a/crypto/dh.c +++ b/crypto/dh.c @@ -83,7 +83,9 @@ static int dh_set_secret(struct crypto_kpp *tfm, const void *buf, unsigned int len) { struct dh_ctx *ctx = dh_get_ctx(tfm); + u8 *rndbuf = NULL; struct dh params; + int maxsize; if (crypto_dh_decode_key(buf, len, ¶ms) < 0) return -EINVAL; @@ -91,7 +93,26 @@ static int dh_set_secret(struct crypto_kpp *tfm, const void *buf, if (dh_set_params(ctx, ¶ms) < 0) return -EINVAL; + if (!params.key || !params.key_size) { + maxsize = crypto_kpp_maxsize(tfm); + if (maxsize < 0) { + dh_clear_params(ctx); + return maxsize; + } + + rndbuf = kmalloc(maxsize, GFP_KERNEL); + if (!rndbuf) { + dh_clear_params(ctx); + return -ENOMEM; + } + + get_random_bytes(rndbuf, maxsize); + params.key = rndbuf; + params.key_size = maxsize; + } + ctx->xa = mpi_read_raw_data(params.key, params.key_size); + kzfree(rndbuf); if (!ctx->xa) { dh_clear_params(ctx); return -EINVAL; -- 2.7.4