Re: [RFC PATCH 5/8] KEYS: Provide software public key query function [ver 3]

From	Tadeusz Struk <tstruk@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 5/8] KEYS: Provide software public key query function [ver 3]
Date	2016-05-12 02:20 +0200
Message-ID	<rxMwa-2kB-3@gated-at.bofh.it> (permalink)
References	<rxDjb-1to-3@gated-at.bofh.it> <rxDjc-1to-21@gated-at.bofh.it> <rxMcO-1Os-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 05/11/2016 04:50 PM, Mat Martineau wrote:
> 
>> +    len = crypto_akcipher_maxsize(tfm);
>> +    info->key_size = len * 8;
>> +    info->max_data_size = len;
>> +    info->max_sig_size = len;
>> +    info->max_enc_size = len;
>> +    info->max_dec_size = len;
> 
> If len > UINT16_MAX, should UINT16_MAX be reported as the max size? Similar question for len*8 and key_size.

Hi Mat,
Since all the operations performed are mod key->n the output will never be bigger
than size of pkey->n, which is the return value from crypto_akcipher_maxsize(tfm)
for a given key.
Thanks,
-- 
TS

Thread

[RFC PATCH 0/8] KEYS: keyctl operations for asymmetric keys [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
  [RFC PATCH 3/8] KEYS: Provide missing asymmetric key subops for new  key type ops [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
  [RFC PATCH 2/8] KEYS: Provide keyctls to drive the new key type ops  for asymmetric keys [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
    Re: [RFC PATCH 2/8] KEYS: Provide keyctls to drive the new key type  ops for asymmetric keys [ver 3] Mat Martineau <mathew.j.martineau@linux.intel.com> - 2016-05-12 00:20 +0200
      Re: [RFC PATCH 2/8] KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver 3] David Howells <dhowells@redhat.com> - 2016-05-12 12:20 +0200
      Re: [RFC PATCH 2/8] KEYS: Provide keyctls to drive the new key type  ops for asymmetric keys [ver 3] David Woodhouse <dwmw2@infradead.org> - 2016-05-12 13:10 +0200
  [RFC PATCH 7/8] KEYS: Implement encrypt,  decrypt and sign for software asymmetric key [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
  [RFC PATCH 5/8] KEYS: Provide software public key query function  [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
    Re: [RFC PATCH 5/8] KEYS: Provide software public key query function  [ver 3] Mat Martineau <mathew.j.martineau@linux.intel.com> - 2016-05-12 02:00 +0200
      Re: [RFC PATCH 5/8] KEYS: Provide software public key query function  [ver 3] Tadeusz Struk <tstruk@gmail.com> - 2016-05-12 02:20 +0200
      Re: [RFC PATCH 5/8] KEYS: Provide software public key query function [ver 3] David Howells <dhowells@redhat.com> - 2016-05-12 12:20 +0200
        Re: [RFC PATCH 5/8] KEYS: Provide software public key query function  [ver 3] Mat Martineau <mathew.j.martineau@linux.intel.com> - 2016-05-12 19:10 +0200
  [RFC PATCH 1/8] KEYS: Provide key type operations for asymmetric  key ops [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
  [RFC PATCH 8/8] KEYS: Implement PKCS#8 RSA Private Key parser [ver  3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
    Re: [RFC PATCH 8/8] KEYS: Implement PKCS#8 RSA Private Key parser  [ver 3] David Woodhouse <dwmw2@infradead.org> - 2016-05-11 21:20 +0200
    Re: [RFC PATCH 8/8] KEYS: Implement PKCS#8 RSA Private Key parser  [ver 3] Mat Martineau <mathew.j.martineau@linux.intel.com> - 2016-05-12 02:20 +0200
      Re: [RFC PATCH 8/8] KEYS: Implement PKCS#8 RSA Private Key parser [ver 3] David Howells <dhowells@redhat.com> - 2016-05-12 12:30 +0200
  [RFC PATCH 4/8] KEYS: Make the X.509 and PKCS7 parsers supply the  sig encoding type [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200
  [RFC PATCH 6/8] KEYS: Allow the public_key struct to hold a private  key [ver 3] David Howells <dhowells@redhat.com> - 2016-05-11 16:30 +0200

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