Re: Struggling with c functions - Mailing list pgsql-hackers

From Olivier PRENANT
Subject Re: Struggling with c functions
Date
Msg-id Pine.UW2.4.21.0104291208300.4987-100000@server.pyrenet.fr
Whole thread Raw
In response to Re: Struggling with c functions  (mlw <markw@mohawksoft.com>)
List pgsql-hackers
Many thanks to you!!!

It now works (did'nt realize that strings where not null
terminated) stupid me!!!

Regards,
On Sat, 28 Apr 2001, mlw wrote:

> You actually almost have it right.
> 
> You are passing VARDATA(user) to crypt, this is wrong.
> 
> You must do something like this:
> 
> int ulen = VARSIZE(user)-VARHDRSZ;
> char utmp[ulen+]; // This works in newer GCC, cool.
> memcpy(utmp,VARDATA(user), len);
> utmp[ulen]=0;
> crypted=crypt(utmp,salt);
> 
> Strings are not gurenteed to be NULL teminated.
> 
> 
> Olivier PRENANT wrote:
> > 
> > Hi all,
> > 
> > I'm rewriting my OLD crypt (Thanks to Henrique) C_fonction to version 0
> > forms :
> > 
> > I have this C file compiled OK to a shared library:
> > 
> > /*
> > *
> > *  Henrique Pantarotto (scanner@cepa.com.br)
> > *  Funcao para encriptar senhas (Function to encrypt passwords)
> > *  September 1999
> > *
> > *  PS: Note that all crypted passwords are created with salt "HP" (my name
> > *  initials..) You can change that, or if you know C, you can do in a way
> > *  that it will pick two random characters (the way it should really be).
> > *
> > */
> > 
> > #include <strings.h>
> > #include <unistd.h>
> > 
> > #include <postgres.h>
> > 
> > text *post_crypt(text *user)
> > {
> >  text *password;
> >  char * crypt();
> >  long now=time((long *) 0);
> >  int len;
> >  char salt[7]="PY", *crypted;
> >  /*strcpy(salt,l64a(now));
> >    salt[3]='\0'; */
> >  crypted=crypt(VARDATA(user),salt);
> >  len=strlen(crypted);
> >  password= palloc((int32) 13 + VARHDRSZ);
> >  VARATT_SIZEP(password)= (int32) VARHDRSZ + 13;
> >  memcpy(VARDATA(password),crypted,len);
> >  return password;
> > }
> > 
> > text *sql_crypt(text *user,text *salt)
> > {
> >   text *password;
> >   char * crypt(), *crypted;
> >   int len;
> >   char s[3];
> >   strncpy(s,VARDATA(salt),2);
> >   s[2]='\0';
> >   crypted=crypt(VARDATA(user),s);
> >   len=strlen(crypted);
> >   password=palloc((int32) 13 + VARHDRSZ);
> >   VARATT_SIZEP(password)=(int32) 13 + VARHDRSZ;
> >   memcpy(VARDATA(password),crypted,len);
> >   return password;
> > }
> > 
> > /*
> > Compile using something like this:
> > 
> > gcc -I/home/postgres/postgresql-6.5.1/src/include -I/home/postgres/postgresql-6.5.1/src/backend -O2 -Wall
-Wmissing-prototypes-fpic -I/home/postgres/postgresql-6.5.1/src/include -c -o encrypt.o encrypt.c
 
> > gcc -shared -o encrypt.so encrypt.o
> > 
> > And last, you create the trigger in PostgreSQL using this:
> > 
> > create function encrypt(text)
> > returns text as '/usr/local/pgsql/lib/encrypt.so' language 'c';
> > 
> > If everything is okay, you'll probably have: select encrypt('secret') working
> > and showing:
> > 
> > encrypt
> > ------------
> > HPK1Jt2NX21G.
> > (1 row)
> > */
> > 
> > I have defined to SQL function:
> > 
> > CREATE FUNCTION post_crypt(text) RETURNS text AS 'xxxx/encrypt.so'
> > CREATE FUNCTION sql_cypt(text,text) RETURNS text AS 'xxxx/encrypt.so';
> > 
> > WHY on earth does
> > 
> > SELECT post_crypt('test'),sql_crypt('test','PY')
> > NOT GIVE the same result???
> > 
> > Please help,
> > 
> > This is most urgent (My customer can't use this function anymore); it
> > worked OK with 7.0.3!!
> > 
> > Regards,
> > --
> > Olivier PRENANT                 Tel:    +33-5-61-50-97-00 (Work)
> > Quartier d'Harraud Turrou           +33-5-61-50-97-01 (Fax)
> > 31190 AUTERIVE                      +33-6-07-63-80-64 (GSM)
> > FRANCE                      Email: ohp@pyrenet.fr
> > ------------------------------------------------------------------------------
> > Make your life a dream, make your dream a reality. (St Exupery)
> > 
> > ---------------------------(end of broadcast)---------------------------
> > TIP 6: Have you searched our list archives?
> > 
> > http://www.postgresql.org/search.mpl
> 
> 

-- 
Olivier PRENANT             Tel:    +33-5-61-50-97-00 (Work)
Quartier d'Harraud Turrou           +33-5-61-50-97-01 (Fax)
31190 AUTERIVE                      +33-6-07-63-80-64 (GSM)
FRANCE                      Email: ohp@pyrenet.fr
------------------------------------------------------------------------------
Make your life a dream, make your dream a reality. (St Exupery)



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