Add random string generator

This commit is contained in:
Jordan Bancino 2022-12-15 03:41:59 +00:00
parent f0392044c2
commit 4f2f7cd966
6 changed files with 56 additions and 2 deletions

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@ -12,7 +12,7 @@ Milestone: v0.1.1
-----------------
[x] DbDelete()
[ ] UtilRandomString()
[x] UtilRandomString()
[ ] Database version file
[ ] User registration

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@ -1,4 +1,4 @@
.Dd $Mdocdate: November 26 2022 $
.Dd $Mdocdate: December 15 2022 $
.Dt UTIL 3
.Os Telodendria Project
.Sh NAME
@ -26,6 +26,8 @@
.Fn UtilGetDelim "char **" "size_t *" "int" "FILE *"
.Ft ssize_t
.Fn UtilGetLine "char **" "size_t *" "FILE *"
.Ft char *
.Fn UtilRandomString "size_t"
.Sh DESCRIPTION
.Pp
This header holds a number of random functions related to strings,
@ -98,6 +100,12 @@ work identically to the POSIX equivalents, documented in
.Xr getdelim 3 ,
except it assumes pointers were allocated using the Memory API, and it
uses the Memory API itself to reallocate necessary pointers.
.Pp
.Fn UtilRandomString
generates a random string of the given length. At the moment, it only
selects from uppercase and lowercase numbers, but the character set may
be expanded in the future, or a function may be added to specify an
arbitrary character set.
.Sh RETURN VALUES
.Pp
.Fn UtilServerTs
@ -131,3 +139,7 @@ and
.Fn UtilGetLine
return the same value as their POSIX equivalents, documented in
.Xr getdelim 3 .
.Pp
.Fn UtilRandomString
returns a string, allocated on the heap, of the given length, or NULL if there
was an error allocating memory.

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@ -43,6 +43,12 @@ While the database is for persistent storage, there may
be some ephemeral data that lives there only for a short
while, so it will be necessary to remove that data when
necessary.
.It
Added a thread-safe random string generator, which will
be used extensively for generating session tokens, device
IDs, access tokens, and more. This generator is seeded by
the current timestamp and the thread ID, so it should be
fairly random.
.El
.Pp
Bug fixes:

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@ -75,6 +75,7 @@ ROUTE_IMPL(RouteRegister, args)
HashMapSet(response, "flows", JsonValueArray(flows));
HashMapSet(response, "params", JsonValueObject(HashMapCreate()));
HashMapSet(response, "session", JsonValueString(UtilRandomString(24)));
}
else
{

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@ -36,6 +36,7 @@
#include <sys/time.h>
#include <sys/stat.h>
#include <limits.h>
#include <pthread.h>
#ifndef PATH_MAX
#define PATH_MAX 256
@ -394,3 +395,34 @@ UtilGetLine(char **linePtr, size_t * n, FILE * stream)
{
return UtilGetDelim(linePtr, n, '\n', stream);
}
char *
UtilRandomString(size_t len)
{
static const char charset[] =
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
char *str;
size_t i;
unsigned int seed = UtilServerTs() * (unsigned long) pthread_self();
if (!len)
{
return NULL;
}
str = Malloc(len + 1);
if (!str)
{
return NULL;
}
for (i = 0; i < len; i++)
{
str[i] = charset[rand_r(&seed) % (sizeof(charset) - 1)];
}
str[len] = '\0';
return str;
}

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@ -59,4 +59,7 @@ extern ssize_t
extern ssize_t
UtilGetLine(char **, size_t *, FILE *);
extern char *
UtilRandomString(size_t);
#endif /* TELODENDRIA_UTIL_H */