Update comment

Author: ssyphi

By Topic/Utility Macros/Random Password Generator.sas

@@ -1,34 +1,30 @@
 /************************************************************************************************
- Random Password Generation
-    1. Defining keyword arguments control the length and characters
-	   used in the password.
-    2. Building a macro variable containing all allowed characters.
-    3. In a loop, using %SUBSTR(%SYSFUNC(RAND)) to pluck random characters...
-    4. ...and appending them to the growing password.
-    5. Testing our macro via a simple loop and various settings.
-    6. Using a random password for an encryption key on a tempoarary dataset.
-
+ RANDOM PASSWORD GENERATION
+    A macro program that generates a random password based on a list of allowed characters.
     Keywords: Macro
 	SAS Versions: SAS 9, SAS Viya
     Documentation: https://go.documentation.sas.com/doc/en/pgmsascdc/default/mcrolref/titlepage.htm
-
-    NOTES:
-	1. Only tested with SAS OnDemand for Academics, as that is the only
-	   SAS version I have access to.
-	2. Does not (currently) support unmatched single or double quote characters
-	   in the special characterw string. I have not tried mismatched left or
-	   right parentheses, either.
+    1. Define keyword arguments control the length and characters used in the password.
+    2. Build a macro variable containing all allowed characters.
+    3. In a loop, use %SUBSTR(%SYSFUNC(RAND)) to select random characters...
+    4. ...and append them to the growing password.
+    5. Test macro via a simple loop and various settings.
+    6. Use a random password for an encryption key on a tempoarary dataset.
+    NOTE: Does not (currently) support unmatched single or double quote characters
+	   in the special characterw string. Mismatched left or right parentheses have not been 
+       tested either.
 ************************************************************************************************/
 
 /************************************************************************************************
- 1. Defining keyword arguments control the length and characters
+ 1. Define keyword arguments control the length and characters
     used in the password.
     a. len= is the desired length of the password, defaulting to 24
 	b. digits= is a Boolean flag, defaulting to TRUE. When TRUE (non-zero),
 	   digits 0-9 are available for use in the password.
 	c. special= is a set of special characters to also use in passwords. Defaults
 	   to those shown in the %NRSTR(). Use special= to not have any specials.
 ************************************************************************************************/
+
 %MACRO RANDPASS(len=24,digits=1,special=%NRSTR(@%&#!?.-_+*,/;:));
 %LOCAL pass;
 %LOCAL chars;
@@ -37,13 +33,14 @@
 %LOCAL i;
 
 /************************************************************************************************
- 2. Building a macro variable containing all allowed characters.
+ 2. Build a macro variable containing all allowed characters.
     a. Add the lowercase letters.
 	b. Add uppercase characters via %UPCASE().
 	c. Add digits, if requested.
 	d. Add special characters. Note the use of %SUPERQ() to avoid issues
 	   with &s and %s that may be present in the string.
 ************************************************************************************************/
+
 %LET chars=abcdefghijklmnopqrstuvwxyz;
 %LET chars=&chars%UPCASE(&chars);
 %IF &digits %THEN
@@ -53,31 +50,34 @@
 %LET numchars=%length(&chars);
 
 %DO i=1 %TO &len;
-	/************************************************************************************************
-	 3. In a loop, using %SUBSTR(%SYSFUNC(RAND)) to pluck random characters...
-	    a. RAND('INTEGER', n) produces a random intger between 1 and n, inclusive
-		   which is exactly what we need.
-		b. %SYSFUNC() invokes it from Macro.
-		c. %SUBSTR(string, N, 1) plucks the Nth character from the string.
-	************************************************************************************************/
-	%LET pick=%SUBSTR(&chars,%SYSFUNC(RAND(INTEGER,&numchars)),1);
-
-	/************************************************************************************************
-	 4. ...and appending them to the growing password.
-	    a. Note in particular the shenanigans here.
-		b. Simply coding "%LET pass=%SUPERQ(pass)&pick" _does_not_work_. Hidden
-		   macro quoting characters end up in &pass, in a nested fashion, and
-		   this produces nested Macro function WARNINGs when the password length
-		   grows to about 12 characters, which is unacceptable.
-		c. The %QSUBSTR() manages to avoid this problem, and also avoids attempts
-		   to resolve any &foo that might appear in the growing password.
-		d. However, %QSUBSTR() can't work on an empty string, so we have to avoid
-		   it first time though, hence the %IF.
-	************************************************************************************************/
-	%IF &i = 1 %THEN
-		%LET pass=&pick;
-	%ELSE
-		%LET pass=%QSUBSTR(%SUPERQ(pass),1)&pick;
+
+/************************************************************************************************
+ 3. In a loop, use %SUBSTR(%SYSFUNC(RAND)) to select random characters...
+    a. RAND('INTEGER', n) produces a random intger between 1 and n, inclusive
+       which is exactly what we need.
+    b. %SYSFUNC() invokes it from Macro.
+    c. %SUBSTR(string, N, 1) plucks the Nth character from the string.
+************************************************************************************************/
+
+    %LET pick=%SUBSTR(&chars,%SYSFUNC(RAND(INTEGER,&numchars)),1);
+
+/************************************************************************************************
+ 4. ...and append them to the growing password.
+    a. Note in particular the shenanigans here.
+    b. Simply coding "%LET pass=%SUPERQ(pass)&pick" _does_not_work_. Hidden
+       macro quoting characters end up in &pass, in a nested fashion, and
+       this produces nested Macro function WARNINGs when the password length
+       grows to about 12 characters, which is unacceptable.
+    c. The %QSUBSTR() manages to avoid this problem, and also avoids attempts
+       to resolve any &foo that might appear in the growing password.
+    d. However, %QSUBSTR() can't work on an empty string, so we have to avoid
+       it first time though, hence the %IF.
+************************************************************************************************/
+
+    %IF &i = 1 %THEN
+        %LET pass=&pick;
+    %ELSE
+        %LET pass=%QSUBSTR(%SUPERQ(pass),1)&pick;
 %END;
 
 %* The result of the macro is this generated password;
@@ -86,45 +86,45 @@
 %MEND;
 
 /************************************************************************************************
- 5. Testing our macro via a simple loop, and various settings.
+ 5. Test macro via a simple loop and various settings.
     a. We need to define a macro for this. Macro now allows %IF statements in
 	   "open code", but not loops.
 	b. Just two cases here. All-defaults, plus longer-no-digits-no-specials.
 	c. The "test" just prints them to the log, for eyeballing.
 	d. Then we run the loop 3 times to get an idea as to what it's doing.
 ************************************************************************************************/
+
 %MACRO TEST(n);
-	%DO i=1 %TO &n;
-		%PUT pw1=%RANDPASS();
-		%PUT pw2=%RANDPASS(len=30,digits=0,special=);
+    %DO i=1 %TO &n;
+        %PUT pw1=%RANDPASS();
+        %PUT pw2=%RANDPASS(len=30,digits=0,special=);
 	%END;
 %MEND;
 
 %TEST(3);
 
-
-
 /************************************************************************************************
- 6. Using a random password for an encryption key on a tempoarary dataset.
+ 6. Use a random password for an encryption key on a tempoarary dataset.
     a. Generate a longish (60 characters) password, safe from prying eyes.
-	b. We import a list of NSA recruits from a secret location no one has
+	b. Import a list of NSA recruits from a secret location no one has
 	   ever heard of, and protect it with AES encryption with our generated
 	   password.
-	c. Now we can run analytics on it safely. Here, we run PROC MEANS, and
+	c. Now we can run analytics on it safely. Run PROC MEANS, and
 	   then ponder why the recruits are all teenagers.
-	d. Now we can drop the table (I used PROC SQL), knowing that even if the
+	d. Drop the table (I used PROC SQL), knowing that even if the
 	   data was recovered from the disk, the encryption renders it unreadable.
 ************************************************************************************************/
+
 %LET pw=%randpass(len=60);
 %*PUT pw=&pw   <== to see it, but its supposed to be a secret;
 
 DATA nsaclass(ENCRYPT=aes ENCRYPTKEY="&pw");
-	SET sashelp.class;
+    SET sashelp.class;
 RUN;
 
 PROC MEANS DATA=nsaclass(ENCRYPTKEY="&pw");
 RUN;
 
 PROC SQL;
-	DROP TABLE nsaclass;
+    DROP TABLE nsaclass;
 QUIT;