Add a rand_util method for generating a random string.

Add a rand_util method for generating a random string.

We need this function to generate a nonce for MAC cookies.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=83588

[abarth-chromium, 2011-04-29 06:06:19]

I can haz reviews?

[Ryan Sleevi, 2011-04-29 06:43:48]

On 2011/04/29 06:06:19, abarth wrote:
> I can haz reviews?

Random drive by: This overlaps with wtc's suggestion for how 
http://codereview.chromium.org/6873156/ should be implemented. Depending on
which is first, may want to ping each other.

[abarth-chromium, 2011-04-29 06:46:38]

On Thu, Apr 28, 2011 at 11:43 PM,  <rsleevi@chromium.org> wrote:
> On 2011/04/29 06:06:19, abarth wrote:
>> I can haz reviews?
>
> Random drive by: This overlaps with wtc's suggestion for how
> http://codereview.chromium.org/6873156/ should be implemented. Depending on
> which is first, may want to ping each other.

I don't care how this is implemented.  I just need a random string.

Adam

[abarth-chromium, 2011-04-29 07:42:36]

http://codereview.chromium.org/6901121/ is the CL that uses this API for those
interested in things in net-land.

[darin (slow to review), 2011-04-29 16:15:36]

http://codereview.chromium.org/6904118/diff/2002/base/rand_util.cc
File base/rand_util.cc (right):

http://codereview.chromium.org/6904118/diff/2002/base/rand_util.cc#newcode52
base/rand_util.cc:52: entropy = RandUint64();
nit: indentation

[abarth-chromium, 2011-04-29 17:56:52]

> http://codereview.chromium.org/6904118/diff/2002/base/rand_util.cc#newcode52
> base/rand_util.cc:52: entropy = RandUint64();
> nit: indentation

Fixenated.

[wtc, 2011-04-29 18:03:56]

http://codereview.chromium.org/6904118/diff/2002/base/rand_util.h
File base/rand_util.h (right):

http://codereview.chromium.org/6904118/diff/2002/base/rand_util.h#newcode33
base/rand_util.h:33: BASE_API std::string RandString(int length);
The |length| parameter should have the type size_t.

This function should be named RandBytes or something along
that line.  "String" implies text (as opposed to binary data)
to most people.  I would also use a C-style buffer
(void* data, size_t length) to receive the output.

[darin (slow to review), 2011-04-29 18:07:45]

On 2011/04/29 18:03:56, wtc wrote:
> This function should be named RandBytes or something along
> that line.  "String" implies text (as opposed to binary data)
> to most people.  I would also use a C-style buffer
> (void* data, size_t length) to receive the output.

Perhaps it is common for consumers to want a random string of bytes.  Maybe
RandBytesAsString would be a reasonable addition to RandBytes?

-Darin

[abarth-chromium, 2011-04-29 18:30:54]

I've uploaded a new version that changes the name to RandBytesAsString.

On 2011/04/29 18:07:45, darin wrote:
> On 2011/04/29 18:03:56, wtc wrote:
> > This function should be named RandBytes or something along
> > that line.  "String" implies text (as opposed to binary data)
> > to most people.  I would also use a C-style buffer
> > (void* data, size_t length) to receive the output.

We store binary data in std::strings elsewhere.  I think it would be fine to
also provide a C-style API, but the having a string return type fits much
current needs slightly better.

> Perhaps it is common for consumers to want a random string of bytes.  Maybe
> RandBytesAsString would be a reasonable addition to RandBytes?

Would you like me to add RandBytes in this patch as well?

[darin (slow to review), 2011-04-29 19:19:32]

if you wanted to implement RandBytesAsString in terms of the RandBytes wtc
suggested, you could do so fairly easily by leveraging WriteInto from
string_util.h.

[darin (slow to review), 2011-04-29 19:19:58]

LGTM... but want to hear back from wtc.

[wtc, 2011-04-29 19:26:07]

LGTM.  I didn't review the unit test.

Adding RandBytes is fine, or you can let qsr do that.

[abarth-chromium, 2011-04-29 20:06:32]

> Adding RandBytes is fine, or you can let qsr do that.

I'm going to land this without RandBytes to unblock the dependent patches.  I'm
happy to implement RandBytes but I'm also equally happy to let qsr have the
glory.

[commit-bot: I haz the power, 2011-04-29 21:03:56]

Change committed as 83588