From: Hannes Reinecke <hare@suse.de> To: Stephan Mueller <smueller@chronox.de>, Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me>, Keith Busch <keith.busch@wdc.com>, linux-nvme@lists.infradead.org, Herbert Xu <herbert@gondor.apana.org.au>, "David S . Miller" <davem@davemloft.net>, linux-crypto@vger.kernel.org Subject: Re: [PATCH 09/11] nvmet: Implement basic In-Band Authentication Date: Tue, 20 Jul 2021 12:14:13 +0200 [thread overview] Message-ID: <aac9448e-29e9-6d03-1077-148be3c10f50@suse.de> (raw) In-Reply-To: <24d115c9b68ca98a3cf363e1cfcb961cc6b38069.camel@chronox.de> On 7/19/21 1:52 PM, Stephan Mueller wrote: > Am Montag, dem 19.07.2021 um 13:10 +0200 schrieb Hannes Reinecke: >> On 7/19/21 12:19 PM, Stephan Mueller wrote: >>> Am Montag, dem 19.07.2021 um 11:57 +0200 schrieb Hannes Reinecke: >>>> On 7/19/21 10:51 AM, Stephan Mueller wrote: [ .. ] >>>>> >>>>> Thank you for clarifying that. It sounds to me that there is no >>>>> defined protocol (or if there, I would be wondering how the code would have >>>>> worked >>>>> with a different implementation). Would it make sense to first specify >>>>> a protocol for authentication and have it discussed? I personally think >>>>> it is a bit difficult to fully understand the protocol from the code and >>>>> discuss protocol-level items based on the code. >>>>> >>>> Oh, the protocol _is_ specified: >>>> >>>> >>>> https://nvmexpress.org/wp-content/uploads/NVM-Express-Base-Specification-2_0-2021.06.02-Ratified-5.pdf >>>> >>>> It's just that I have issues translating that spec onto what the kernel >>>> provides. >>> >>> according to the naming conventions there in figures 447 and following: >>> >>> - x and y: DH private key (kernel calls it secret set with dh_set_secret >>> or >>> encoded into param.key) >>> >> >> But that's were I got confused; one needs a private key here, but there >> is no obvious candidate for it. But reading it more closely I guess the >> private key is just a random number (cf the spec: g^y mod p, where y is >> a random number selected by the host that shall be at least 256 bits >> long). So I'll fix it up with the next round. > > Here comes the crux: the kernel has an ECC private key generation function > ecdh_set_secret triggered with crypto_kpp_set_secret using a NULL key, but it > has no FFC-DH counterpart. > > That said, generating a random number is the most obvious choice, but not the > right one. > > The correct one would be following SP800-56A rev 3 and here either section > 5.6.1.1.3 or 5.6.1.1.4. > Hmm. Okay. But after having read section 5.6.1.1.4, I still do have some questions. Assume we will be using a bit length of 512 for FFDHE, then we will trivially pass Step 2 for all supported FFDHE groups (the maximum symmetric-equivalent strength for ffdhe8192 is 192 bits). From my understanding, the random number generator will fill out all available bytes in the string (and nothing more), so we trivially satisfy step 3 and 4. And as q is always larger than the random number, step 6 reduces to 'if (c > 2^N - 2)', ie we just need to check if the random number is a string of 0xff characters. Which hardly is a random number at all, so it'll be impossible to get this. Which then would mean that our 'x' is simply the random number + 1, which arguably is slightly pointless (one more than a random number is as random as the number itself), so I do feel justified with just returning a random number here. Am I wrong with that reasoning? Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), GF: Felix Imendörffer
WARNING: multiple messages have this Message-ID (diff)
From: Hannes Reinecke <hare@suse.de> To: Stephan Mueller <smueller@chronox.de>, Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me>, Keith Busch <keith.busch@wdc.com>, linux-nvme@lists.infradead.org, Herbert Xu <herbert@gondor.apana.org.au>, "David S . Miller" <davem@davemloft.net>, linux-crypto@vger.kernel.org Subject: Re: [PATCH 09/11] nvmet: Implement basic In-Band Authentication Date: Tue, 20 Jul 2021 12:14:13 +0200 [thread overview] Message-ID: <aac9448e-29e9-6d03-1077-148be3c10f50@suse.de> (raw) In-Reply-To: <24d115c9b68ca98a3cf363e1cfcb961cc6b38069.camel@chronox.de> On 7/19/21 1:52 PM, Stephan Mueller wrote: > Am Montag, dem 19.07.2021 um 13:10 +0200 schrieb Hannes Reinecke: >> On 7/19/21 12:19 PM, Stephan Mueller wrote: >>> Am Montag, dem 19.07.2021 um 11:57 +0200 schrieb Hannes Reinecke: >>>> On 7/19/21 10:51 AM, Stephan Mueller wrote: [ .. ] >>>>> >>>>> Thank you for clarifying that. It sounds to me that there is no >>>>> defined protocol (or if there, I would be wondering how the code would have >>>>> worked >>>>> with a different implementation). Would it make sense to first specify >>>>> a protocol for authentication and have it discussed? I personally think >>>>> it is a bit difficult to fully understand the protocol from the code and >>>>> discuss protocol-level items based on the code. >>>>> >>>> Oh, the protocol _is_ specified: >>>> >>>> >>>> https://nvmexpress.org/wp-content/uploads/NVM-Express-Base-Specification-2_0-2021.06.02-Ratified-5.pdf >>>> >>>> It's just that I have issues translating that spec onto what the kernel >>>> provides. >>> >>> according to the naming conventions there in figures 447 and following: >>> >>> - x and y: DH private key (kernel calls it secret set with dh_set_secret >>> or >>> encoded into param.key) >>> >> >> But that's were I got confused; one needs a private key here, but there >> is no obvious candidate for it. But reading it more closely I guess the >> private key is just a random number (cf the spec: g^y mod p, where y is >> a random number selected by the host that shall be at least 256 bits >> long). So I'll fix it up with the next round. > > Here comes the crux: the kernel has an ECC private key generation function > ecdh_set_secret triggered with crypto_kpp_set_secret using a NULL key, but it > has no FFC-DH counterpart. > > That said, generating a random number is the most obvious choice, but not the > right one. > > The correct one would be following SP800-56A rev 3 and here either section > 5.6.1.1.3 or 5.6.1.1.4. > Hmm. Okay. But after having read section 5.6.1.1.4, I still do have some questions. Assume we will be using a bit length of 512 for FFDHE, then we will trivially pass Step 2 for all supported FFDHE groups (the maximum symmetric-equivalent strength for ffdhe8192 is 192 bits). From my understanding, the random number generator will fill out all available bytes in the string (and nothing more), so we trivially satisfy step 3 and 4. And as q is always larger than the random number, step 6 reduces to 'if (c > 2^N - 2)', ie we just need to check if the random number is a string of 0xff characters. Which hardly is a random number at all, so it'll be impossible to get this. Which then would mean that our 'x' is simply the random number + 1, which arguably is slightly pointless (one more than a random number is as random as the number itself), so I do feel justified with just returning a random number here. Am I wrong with that reasoning? Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), GF: Felix Imendörffer _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme
next prev parent reply other threads:[~2021-07-20 10:15 UTC|newest] Thread overview: 163+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-16 11:04 [RFC PATCH 00/11] nvme: In-band authentication support Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-16 11:04 ` [PATCH 01/11] crypto: add crypto_has_shash() Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 6:08 ` Sagi Grimberg 2021-07-17 6:08 ` Sagi Grimberg 2021-07-16 11:04 ` [PATCH 02/11] crypto: add crypto_has_kpp() Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 6:08 ` Sagi Grimberg 2021-07-17 6:08 ` Sagi Grimberg 2021-07-16 11:04 ` [PATCH 03/11] crypto/ffdhe: Finite Field DH Ephemeral Parameters Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 6:14 ` Sagi Grimberg 2021-07-17 6:14 ` Sagi Grimberg 2021-07-17 13:57 ` Hannes Reinecke 2021-07-17 13:57 ` Hannes Reinecke 2021-07-17 15:03 ` Stephan Müller 2021-07-17 15:03 ` Stephan Müller 2021-07-18 12:22 ` Hannes Reinecke 2021-07-18 12:22 ` Hannes Reinecke 2021-07-16 11:04 ` [PATCH 04/11] lib/base64: RFC4648-compliant base64 encoding Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 6:16 ` Sagi Grimberg 2021-07-17 6:16 ` Sagi Grimberg 2021-07-17 14:00 ` Hannes Reinecke 2021-07-17 14:00 ` Hannes Reinecke 2021-07-17 14:12 ` Eric Biggers 2021-07-17 14:12 ` Eric Biggers 2021-07-17 14:20 ` Eric Biggers 2021-07-17 14:20 ` Eric Biggers 2021-07-16 11:04 ` [PATCH 05/11] nvme: add definitions for NVMe In-Band authentication Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 6:30 ` Sagi Grimberg 2021-07-17 6:30 ` Sagi Grimberg 2021-07-17 14:04 ` Hannes Reinecke 2021-07-17 14:04 ` Hannes Reinecke 2021-07-20 20:26 ` Vladislav Bolkhovitin 2021-07-20 20:26 ` Vladislav Bolkhovitin 2021-07-16 11:04 ` [PATCH 06/11] nvme: Implement " Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 7:22 ` Sagi Grimberg 2021-07-17 7:22 ` Sagi Grimberg 2021-07-18 12:21 ` Hannes Reinecke 2021-07-18 12:21 ` Hannes Reinecke 2021-07-19 8:47 ` Sagi Grimberg 2021-07-19 8:47 ` Sagi Grimberg 2021-07-20 20:28 ` Vladislav Bolkhovitin 2021-07-20 20:28 ` Vladislav Bolkhovitin 2021-07-21 6:12 ` Hannes Reinecke 2021-07-21 6:12 ` Hannes Reinecke 2021-07-17 16:49 ` Stephan Müller 2021-07-17 16:49 ` Stephan Müller 2021-07-18 12:43 ` Hannes Reinecke 2021-07-18 12:43 ` Hannes Reinecke 2021-07-18 12:47 ` Stephan Müller 2021-07-18 12:47 ` Stephan Müller 2021-07-20 20:27 ` Vladislav Bolkhovitin 2021-07-20 20:27 ` Vladislav Bolkhovitin 2021-07-21 6:08 ` Hannes Reinecke 2021-07-21 6:08 ` Hannes Reinecke 2021-07-21 12:10 ` Vladislav Bolkhovitin 2021-07-21 12:10 ` Vladislav Bolkhovitin 2021-07-16 11:04 ` [PATCH 07/11] nvme-auth: augmented challenge support Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 16:49 ` Stephan Müller 2021-07-17 16:49 ` Stephan Müller 2021-07-18 12:27 ` Hannes Reinecke 2021-07-18 12:27 ` Hannes Reinecke 2021-07-18 12:57 ` Stephan Müller 2021-07-18 12:57 ` Stephan Müller 2021-07-19 9:21 ` Sagi Grimberg 2021-07-19 9:21 ` Sagi Grimberg 2021-07-20 13:12 ` Hannes Reinecke 2021-07-20 13:12 ` Hannes Reinecke 2021-07-16 11:04 ` [PATCH 08/11] nvmet: Parse fabrics commands on all queues Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-19 9:21 ` Sagi Grimberg 2021-07-19 9:21 ` Sagi Grimberg 2021-07-16 11:04 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 16:49 ` Stephan Müller 2021-07-17 16:49 ` Stephan Müller 2021-07-18 12:37 ` Hannes Reinecke 2021-07-18 12:37 ` Hannes Reinecke 2021-07-18 12:56 ` Stephan Müller 2021-07-18 12:56 ` Stephan Müller 2021-07-19 8:15 ` Hannes Reinecke 2021-07-19 8:15 ` Hannes Reinecke 2021-07-19 8:51 ` Stephan Mueller 2021-07-19 8:51 ` Stephan Mueller 2021-07-19 9:57 ` Hannes Reinecke 2021-07-19 9:57 ` Hannes Reinecke 2021-07-19 10:19 ` Stephan Mueller 2021-07-19 10:19 ` Stephan Mueller 2021-07-19 11:10 ` Hannes Reinecke 2021-07-19 11:10 ` Hannes Reinecke 2021-07-19 11:52 ` Stephan Mueller 2021-07-19 11:52 ` Stephan Mueller 2021-07-19 12:08 ` Hannes Reinecke 2021-07-19 12:08 ` Hannes Reinecke 2021-07-20 10:14 ` Hannes Reinecke [this message] 2021-07-20 10:14 ` Hannes Reinecke 2021-07-20 10:49 ` Simo Sorce 2021-07-20 10:49 ` Simo Sorce 2021-07-20 11:31 ` Hannes Reinecke 2021-07-20 11:31 ` Hannes Reinecke 2021-07-20 14:44 ` Simo Sorce 2021-07-20 14:44 ` Simo Sorce 2021-07-20 14:47 ` Stephan Mueller 2021-07-20 14:47 ` Stephan Mueller 2021-07-23 20:02 ` Vladislav Bolkhovitin 2021-07-23 20:02 ` Vladislav Bolkhovitin 2021-07-18 13:26 ` Herbert Xu 2021-07-18 13:26 ` Herbert Xu 2021-07-19 20:38 ` Sagi Grimberg 2021-07-19 20:38 ` Sagi Grimberg 2021-07-20 6:08 ` Hannes Reinecke 2021-07-20 6:08 ` Hannes Reinecke 2021-07-16 11:04 ` [PATCH 10/11] nvmet-auth: implement support for augmented challenge Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 16:49 ` Stephan Müller 2021-07-17 16:49 ` Stephan Müller 2021-07-18 12:25 ` Hannes Reinecke 2021-07-18 12:25 ` Hannes Reinecke 2021-07-16 11:04 ` [PATCH 11/11] nvme: add non-standard ECDH and curve25517 algorithms Hannes Reinecke 2021-07-16 11:04 ` Hannes Reinecke 2021-07-17 16:50 ` Stephan Müller 2021-07-17 16:50 ` Stephan Müller 2021-07-18 12:44 ` Hannes Reinecke 2021-07-18 12:44 ` Hannes Reinecke 2021-07-19 9:23 ` Sagi Grimberg 2021-07-19 9:23 ` Sagi Grimberg 2021-07-19 9:56 ` Hannes Reinecke 2021-07-19 9:56 ` Hannes Reinecke 2021-07-17 6:06 ` [RFC PATCH 00/11] nvme: In-band authentication support Sagi Grimberg 2021-07-17 6:06 ` Sagi Grimberg 2021-07-19 10:02 ` Simo Sorce 2021-07-19 10:02 ` Simo Sorce 2021-07-19 11:11 ` Hannes Reinecke 2021-07-19 11:11 ` Hannes Reinecke 2021-07-20 20:26 ` Vladislav Bolkhovitin 2021-07-20 20:26 ` Vladislav Bolkhovitin 2021-07-21 6:06 ` Hannes Reinecke 2021-07-21 6:06 ` Hannes Reinecke 2021-07-21 12:10 ` Vladislav Bolkhovitin 2021-07-21 12:10 ` Vladislav Bolkhovitin 2021-07-23 20:02 ` Vladislav Bolkhovitin 2021-07-23 20:02 ` Vladislav Bolkhovitin 2021-07-24 11:17 ` Hannes Reinecke 2021-07-24 11:17 ` Hannes Reinecke 2022-03-23 7:12 [PATCHv9 " Hannes Reinecke 2022-03-23 7:13 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-03-28 8:08 [PATCHv10 00/11] nvme: In-band authentication support Hannes Reinecke 2022-03-28 8:08 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-03-28 13:39 [PATCHv11 00/11] nvme: In-band authentication support Hannes Reinecke 2022-03-28 13:39 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-05-18 11:22 [PATCHv12 00/11] nvme: In-band authentication support Hannes Reinecke 2022-05-18 11:22 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-05-22 11:44 ` Max Gurtovoy 2022-05-23 6:03 ` Hannes Reinecke 2022-05-25 10:42 ` Sagi Grimberg 2022-06-07 10:46 ` Christoph Hellwig 2022-06-08 14:45 [PATCHv14 00/11] nvme: In-band authentication support Hannes Reinecke 2022-06-08 14:45 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-06-21 9:02 [PATCHv15 00/11] nvme: In-band authentication support Hannes Reinecke 2022-06-21 9:02 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-06-21 17:24 [PATCHv16 00/11] nvme: In-band authentication support Hannes Reinecke 2022-06-21 17:24 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-06-23 6:17 [PATCHv17 00/11] nvme: In-band authentication support Hannes Reinecke 2022-06-23 6:17 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke 2022-06-27 9:51 [PATCHv18 00/11] nvme: In-band authentication support Hannes Reinecke 2022-06-27 9:52 ` [PATCH 09/11] nvmet: Implement basic In-Band Authentication Hannes Reinecke
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