From: Eric Biggers <ebiggers3@gmail.com>
To: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: linux-crypto@vger.kernel.org,
Herbert Xu <herbert@gondor.apana.org.au>,
keyrings@vger.kernel.org,
Mat Martineau <mathew.j.martineau@linux.intel.com>,
Salvatore Benedetto <salvatore.benedetto@intel.com>,
Stephan Mueller <smueller@chronox.de>,
Eric Biggers <ebiggers@google.com>,
stable@vger.kernel.org
Subject: Re: [PATCH 2/4] crypto: dh - don't permit 'p' to be 0
Date: Thu, 02 Nov 2017 17:31:41 +0000 [thread overview]
Message-ID: <20171102173141.GB23035@gmail.com> (raw)
In-Reply-To: <281c8d97-7d44-d157-5221-1487ec03a06f@microchip.com>
On Thu, Nov 02, 2017 at 01:40:51PM +0200, Tudor Ambarus wrote:
> Hi, Eric,
>
> On 11/02/2017 12:25 AM, Eric Biggers wrote:
> >If 'p' is 0 for the software Diffie-Hellman implementation, then
> >dh_max_size() returns 0.
>
> dh_set_secret() returns -EINVAL if p_len < 1536, see
> dh_check_params_length(). What am I missing?
>
> Cheers,
> ta
You pass a buffer containing 0's, not a buffer of length 0. The buffer is
interpreted as an arbitrary precision integer, so any length buffer filled with
0's has the mathematical value 0.
Eric
WARNING: multiple messages have this Message-ID (diff)
From: Eric Biggers <ebiggers3@gmail.com>
To: Tudor Ambarus <tudor.ambarus@microchip.com>
Cc: linux-crypto@vger.kernel.org,
Herbert Xu <herbert@gondor.apana.org.au>,
keyrings@vger.kernel.org,
Mat Martineau <mathew.j.martineau@linux.intel.com>,
Salvatore Benedetto <salvatore.benedetto@intel.com>,
Stephan Mueller <smueller@chronox.de>,
Eric Biggers <ebiggers@google.com>,
stable@vger.kernel.org
Subject: Re: [PATCH 2/4] crypto: dh - don't permit 'p' to be 0
Date: Thu, 2 Nov 2017 10:31:41 -0700 [thread overview]
Message-ID: <20171102173141.GB23035@gmail.com> (raw)
In-Reply-To: <281c8d97-7d44-d157-5221-1487ec03a06f@microchip.com>
On Thu, Nov 02, 2017 at 01:40:51PM +0200, Tudor Ambarus wrote:
> Hi, Eric,
>
> On 11/02/2017 12:25 AM, Eric Biggers wrote:
> >If 'p' is 0 for the software Diffie-Hellman implementation, then
> >dh_max_size() returns 0.
>
> dh_set_secret() returns -EINVAL if p_len < 1536, see
> dh_check_params_length(). What am I missing?
>
> Cheers,
> ta
You pass a buffer containing 0's, not a buffer of length 0. The buffer is
interpreted as an arbitrary precision integer, so any length buffer filled with
0's has the mathematical value 0.
Eric
next prev parent reply other threads:[~2017-11-02 17:31 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-01 22:25 [PATCH 0/4] crypto: dh - input validation fixes Eric Biggers
2017-11-01 22:25 ` Eric Biggers
2017-11-01 22:25 ` [PATCH 1/4] crypto: dh - fix double free of ctx->p Eric Biggers
2017-11-01 22:25 ` Eric Biggers
2017-11-02 10:55 ` Tudor Ambarus
2017-11-02 10:55 ` Tudor Ambarus
2017-11-02 17:30 ` Eric Biggers
2017-11-02 17:30 ` Eric Biggers
2017-11-01 22:25 ` [PATCH 2/4] crypto: dh - don't permit 'p' to be 0 Eric Biggers
2017-11-01 22:25 ` Eric Biggers
2017-11-02 11:40 ` Tudor Ambarus
2017-11-02 11:40 ` Tudor Ambarus
2017-11-02 17:31 ` Eric Biggers [this message]
2017-11-02 17:31 ` Eric Biggers
2017-11-03 6:23 ` Tudor Ambarus
2017-11-03 6:23 ` Tudor Ambarus
2017-11-01 22:25 ` [PATCH 3/4] crypto: qat - fix double free of ctx->p Eric Biggers
2017-11-01 22:25 ` Eric Biggers
2017-11-02 17:34 ` Eric Biggers
2017-11-02 17:34 ` Eric Biggers
2017-11-01 22:25 ` [PATCH 4/4] crypto: dh - don't permit 'key' or 'g' size longer than 'p' Eric Biggers
2017-11-01 22:25 ` Eric Biggers
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