rfc:argon2_password_hash

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rfc:argon2_password_hash [2016/08/06 14:51] – charlesportwoodiirfc:argon2_password_hash [2018/03/01 23:27] (current) – RFC was implemented in PHP 7.2 carusogabriel
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 ====== PHP RFC: Argon2 Password Hash ====== ====== PHP RFC: Argon2 Password Hash ======
-  * Version: 0.6+  * Version: 0.8
   * Date: 2016-07-10   * Date: 2016-07-10
   * Author: Charles R. Portwood II <charlesportwoodii@erianna.com>   * Author: Charles R. Portwood II <charlesportwoodii@erianna.com>
-  * Status: Under Discussion+  * Status: Implemented (in PHP 7.2)
   * First Published at: http://wiki.php.net/rfc/argon2_password_hash   * First Published at: http://wiki.php.net/rfc/argon2_password_hash
  
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   - And a parallelism factor, which defines the number of parallel threads   - And a parallelism factor, which defines the number of parallel threads
  
-Argon2 comes in two distinct flavors, Argon2i and Argon2d. Argon2i which is optimized for password hashing and password based key derivation. Argon2 is faster and uses data-dependent memory access, making it highly resistant against GPU cracking attacks and suitable for applications with no threats from side-channel timing attacks (such as cryptocurrencies).+Argon2 comes in two distinct flavors, Argon2i and Argon2d. Argon2i which is optimized for password hashing and password based key derivation. Argon2d is faster and uses data-dependent memory access, making it highly resistant against GPU cracking attacks and suitable for applications with no threats from side-channel timing attacks (such as cryptocurrencies).
  
 ===== Proposal ===== ===== Proposal =====
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 <code> <code>
-memory_cost = 64 Mib +memory_cost = 1024 KiB 
-time_cost = 3 +time_cost = 2 
-threads = 1+threads = 2
 </code> </code>
 +
 +All three values are integers. The memory cost represents the number of KiB that should be consumed during hashing. The default value is 1<<10, or 1024 KiB, or 1 MiB. The argon2 spec recommends setting the memory cost to a power of 2 when changing.
 +
 +The time cost represents the number of times the hash algorithm will be run. And the thread parameter indicates the number of CPU threads that will be used during hashing.
  
 ==== Changes to password_hash() ==== ==== Changes to password_hash() ====
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 None. None.
  
-===== Open Issues =====+===== Discussion Issues =====
  
-==== Cost factors ====+All issues in this section have been resolved. The primary discussion points and resolutions are outlined.
  
-This library proposes the following cost factors:+==== [Resolved] Cost factors ==== 
 + 
 +This library initially proposed higher cost factors, but now proposes the following cost factors:
  
 <code> <code>
-memory_cost = 64 Mib //16 +memory_cost = 1 MiB 
-time_cost = 3 +time_cost = 2 
-threads = 1+threads = 2
 </code> </code>
  
-These values are derived from recommendations from other libraries, and a recommendation from one of the developers. The reference library comes with a CLI program that lists the following defaults which could be used to make this implementation more appealing to those on systems with limited memory.+Due to the variety of platforms PHP runs on, the cost factors are deliberately set low as to not accidentally exhaust system resources on shared or low resource systems when using the default cost parameters. Consequently, users should adjust the cost factors to match the system they're working on. The following list outlines hashing performance on various systems using these default cost values.
  
-<code> +  - Common Cloud Server 512 MB, 1 Core: 3-5 ms 
-memory_cost = 4 Mib // 12 +  - Common Cloud Server 2 GB, 2 Core, 1-3 ms 
-time_cost = 3 +  - 512 MB Raspberry Pi Zero: 75-85ms 
-threads = 1 + 
-</code>+As Argon2 doesn't have any "bad" values, however consuming more resources is considered better than consuming less. Users are encouraged to adjust the cost factors for the platform they're developing for.
  
 ==== [Resolved] m_cost, t_costs vs memory_cost, time_cost ==== ==== [Resolved] m_cost, t_costs vs memory_cost, time_cost ====
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 The reference material uses m_cost and t_cost. End users might find it easier to use memory_cost and time_cost. The cost variables have been changed to the latter to simplify cost selection for the end user. The reference material uses m_cost and t_cost. End users might find it easier to use memory_cost and time_cost. The cost variables have been changed to the latter to simplify cost selection for the end user.
  
-==== [Resolved ]Providing default options ====+==== [Resolved] Providing default options ====
  
 Providing default options allows for ease of use, and encourages use. Not providing options encourages experimentation on your system, but discourages use from people unfamiliar with the algorithm. Providing default options allows for ease of use, and encourages use. Not providing options encourages experimentation on your system, but discourages use from people unfamiliar with the algorithm.
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 Vote YES to include Argon2 as an alternative to Bcrypt within the password_* functions in 7.2. A 50%+1 majority should be sufficient. Vote YES to include Argon2 as an alternative to Bcrypt within the password_* functions in 7.2. A 50%+1 majority should be sufficient.
  
-Voting will be open for 1 week.+Voting will be open for 2 weeks.
  
-<doodle title="argon2_password_hash_revote" auth="charlesportwoodii" voteType="single" closed="false">+<doodle title="argon2_password_hash_revote" auth="charlesportwoodii" voteType="single" closed="true">
    * Yes    * Yes
    * No    * No
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 ===== Patches and Tests ===== ===== Patches and Tests =====
  
-A working patch is available at: https://github.com/php/php-src/pull/1997+A working patch against the latest version of the Argon2 reference library is available at: https://github.com/php/php-src/pull/1997
  
 ===== Implementation ===== ===== Implementation =====
-After the project is implemented, this section should contain  +  - Merged in 7.2 
-  - the version(s) it was merged to +  - Commit: https://github.com/php/php-src/commit/35a74b9e4a9b5812c0e3a5524e28ff7dec50f1dc
-  - a link to the git commit(s)+
   - a link to the PHP manual entry for the feature   - a link to the PHP manual entry for the feature
  
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   - 2016-08-01: 0.5 Voting closes due to issue with RFC, removing 7.4 and adding new issues brought up during vote   - 2016-08-01: 0.5 Voting closes due to issue with RFC, removing 7.4 and adding new issues brought up during vote
   - 2016-08-01: 0.6 Removing Argon2 from password_*, changing configure flag to --with-password-argon2 for clarity of scope   - 2016-08-01: 0.6 Removing Argon2 from password_*, changing configure flag to --with-password-argon2 for clarity of scope
 +  - 2016-08-18: 0.7 Adding clarity on new cost factors 
 +  - 2016-08-24: 0.8 Voting re-opened 
 +  - 2016-09-08: 0.8 RFC accepted, voting closed
rfc/argon2_password_hash.1470495110.txt.gz · Last modified: 2017/09/22 13:28 (external edit)

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