Issue #7854 has been reported by Student (Nathan Zook). ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-02-15 00:53
on 2013-02-15 02:43
Issue #7854 has been updated by phluid61 (Matthew Kerwin).
Note that this is closely related to #7795 (Symbol.defined? and/or
to_existing_symbol)
In existing code, Symbol.[] could be implemented as:
class Symbol
def self.[](string)
all_symbols.find{|sym| sym.to_s == string}
end
end
----------------------------------------
Feature #7854: New method Symbol[string]
https://bugs.ruby-lang.org/issues/7854#change-36300
Author: Student (Nathan Zook)
Status: Open
Priority: Normal
Assignee:
Category: core
Target version: next minor
I propose a new class method [] on Symbol. If a symbol s already exists
such that s.to_s == string, then s is returned. If not, nil is
returned.
The inspiration for this method is a question I was asked, and the
answer I was given: "Why would you want to turn a tainted string into a
symbol?" "I don't--I want to access an existing symbol with tainted
data". Symbol[] accesses the symbol table like hash[] accesses the
elements of a hash.
I believe that this completely addresses the problems behind tickets
#7791 and #7839. I believe that it is a more intuitive solution than my
proposal #7795, and I believe that this will also be useful for
YAML.safe_load and similar initiatives.
on 2013-02-15 02:55
Issue #7854 has been updated by Student (Nathan Zook). It could, but it would be extraordinarily slow, as all_symbols returns an array. ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-36302 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-02-15 04:59
Issue #7854 has been updated by drbrain (Eric Hodel). To make this proposal useful all existing libraries must be updated to use the method to create symbols. Other proposals such as #7839 or #7791 allow rubyists to avoid a symbol creation DoS without forcing them to ask for new releases of a library. ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-36305 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-02-15 05:59
Issue #7854 has been updated by Student (Nathan Zook).
=begin
Ticket #7839 requires the manipulation of global state. I'm not sure
why I have to explain that this is a REALLY bad idea.
Ticket #7791 has two possible implementations. One is to GC symbols
globally. This would require treating not just symbols like objects,
but methods (whose names are in fact symbols) as well. I do not believe
that methods are even currently part of the object system.
Another implementation would be to divide symbols into two kinds
depending on how they are created. The theory being that symbols used
for method names would be immune to GC. The first problem with this is
that there is no reason to believe that method declarations are the
first place that a particular symbol would be declared. The second is
that dynamic method creation is an important part of ruby. If the goal
is to protect against memory leaks in this fashion, it is not at all
certain that the leak does not extend into the realm of method creation.
In other words, both of these implementations involve complex changes to
the guts of Ruby, and lead to the likelihood of a significant
behavioural fork with other rubys. (Not to mention the relatively high
risk of bug introduction.) Since this is a security feature, I think
that it is important to lead the way in a direction that is easy to
import to other rubies (and also to backport as a security patch!) I
expect Symbol[] to have a very straightforward implementation that is
well-isolated from the rest of Ruby, with the possible exception of
YAML.*load*, which might well benefit from such a feature.
As for requiring the libraries to all be updated to make use of this
feature--I consider that to be a good thing. #7839 creates a change in
MRI's behaviour that WILL break apparently "safe" use of existing
libraries. #7791 necessarily dramatically affects Symbol's runtime
performance, and thus means that any highly-tuned ruby is going to have
issues--assuming that no bugs occur, and that the other rubys pick it
up.
Furthermore, for most, perhaps even all, libraries, (({grep -R to_sym
lib})) is going to tell you what you need to examine to make use of this
feature. Certainly, it would be nice to avoid having to do such things,
but because of the recent exploits, the more security-minded portion of
the community (such as myself) is ALREADY nervously poking around in
their libraries.
This feature gives the community a clean way to patch questionable code,
which is itself relatively easy to identify in manner that makes it easy
for other rubies to quickly follow. I do not believe that the other
proposals do.
=end
----------------------------------------
Feature #7854: New method Symbol[string]
https://bugs.ruby-lang.org/issues/7854#change-36307
Author: Student (Nathan Zook)
Status: Open
Priority: Normal
Assignee:
Category: core
Target version: next minor
I propose a new class method [] on Symbol. If a symbol s already exists
such that s.to_s == string, then s is returned. If not, nil is
returned.
The inspiration for this method is a question I was asked, and the
answer I was given: "Why would you want to turn a tainted string into a
symbol?" "I don't--I want to access an existing symbol with tainted
data". Symbol[] accesses the symbol table like hash[] accesses the
elements of a hash.
I believe that this completely addresses the problems behind tickets
#7791 and #7839. I believe that it is a more intuitive solution than my
proposal #7795, and I believe that this will also be useful for
YAML.safe_load and similar initiatives.
on 2013-02-18 01:35
Issue #7854 has been updated by ko1 (Koichi Sasada). Assignee set to matz (Yukihiro Matsumoto) ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-36476 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-03-07 04:55
Issue #7854 has been updated by phluid61 (Matthew Kerwin).
File symbol_lookup.patch added
=begin
I've attached a patch that defines ((%Symbol[str]%)). If ((|str|)) is a
string and there exists a symbol such that (({symbol.to_s == str})), it
returns that symbol. Otherwise it returns ((|nil|)). Raises a
TypeError if ((|str|)) is not a string.
I also made a unit test, currently available as a gist:
https://gist.github.com/phluid61/5105458
=end
----------------------------------------
Feature #7854: New method Symbol[string]
https://bugs.ruby-lang.org/issues/7854#change-37348
Author: Student (Nathan Zook)
Status: Open
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: next minor
I propose a new class method [] on Symbol. If a symbol s already exists
such that s.to_s == string, then s is returned. If not, nil is
returned.
The inspiration for this method is a question I was asked, and the
answer I was given: "Why would you want to turn a tainted string into a
symbol?" "I don't--I want to access an existing symbol with tainted
data". Symbol[] accesses the symbol table like hash[] accesses the
elements of a hash.
I believe that this completely addresses the problems behind tickets
#7791 and #7839. I believe that it is a more intuitive solution than my
proposal #7795, and I believe that this will also be useful for
YAML.safe_load and similar initiatives.
on 2013-03-07 07:05
Issue #7854 has been updated by Student (Nathan Zook). :) ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-37351 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-03-07 13:50
Issue #7854 has been updated by nobu (Nobuyoshi Nakada). To obtain existing symbol, rb_check_id() is already available, so you don't have to add new extern function. ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-37356 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-03-08 00:48
Issue #7854 has been updated by phluid61 (Matthew Kerwin). File symbol_lookup2.patch added nobu (Nobuyoshi Nakada) wrote: > To obtain existing symbol, rb_check_id() is already available, so you don't have to add new extern function. Thank you for the feedback. With that in mind, I've made a less invasive version which only modifies string.c Please let me know if my enthusiasm gets annoying. :) ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-37370 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-03-08 10:36
Issue #7854 has been updated by nobu (Nobuyoshi Nakada). Why does it have -1 arity? And I don't think it's harmful if the method allows a Smbol too. ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-37387 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
on 2013-03-09 09:59
Issue #7854 has been updated by phluid61 (Matthew Kerwin). File symbol_lookup3.patch added File symbol_lookup3_warn.patch added nobu (Nobuyoshi Nakada) wrote: > Why does it have -1 arity? > > And I don't think it's harmful if the method allows a Smbol too. To the first: an oversight on my part, there's no real reason. I have rewritten it with an arity of 1. To the second: I can easily change it to allow a Symbol as well. However since the original discussion that spawned this proposal was focused on the idea of not creating unwanted/unneeded Symbols, I wonder should it emit a warning in that case? I see now, too, that I was rather overzealous in my original attempts. I should have realised most of the hard work has already been done. :) Now I suppose it's up to Matz to approve it or not. ---------------------------------------- Feature #7854: New method Symbol[string] https://bugs.ruby-lang.org/issues/7854#change-37420 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: matz (Yukihiro Matsumoto) Category: core Target version: next minor I propose a new class method [] on Symbol. If a symbol s already exists such that s.to_s == string, then s is returned. If not, nil is returned. The inspiration for this method is a question I was asked, and the answer I was given: "Why would you want to turn a tainted string into a symbol?" "I don't--I want to access an existing symbol with tainted data". Symbol[] accesses the symbol table like hash[] accesses the elements of a hash. I believe that this completely addresses the problems behind tickets #7791 and #7839. I believe that it is a more intuitive solution than my proposal #7795, and I believe that this will also be useful for YAML.safe_load and similar initiatives.
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