Add a .pragma directive for configuration files

Currently added pragma:

.pragma dollarid:on

This allows dollar signs to be a keyword character unless it's
followed by a opening brace or parenthesis.

Fixes #8207

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8882)

CHANGES

@@ -9,6 +9,18 @@
 
  Changes between 1.1.1 and 3.0.0 [xx XXX xxxx]
 
+  *) Added a .pragma directive to the syntax of configuration files, to
+     allow varying behavior in a supported and predictable manner.
+     Currently added pragma:
+
+     .pragma dollarid:on
+
+     This allows dollar signs to be a keyword character unless it's
+     followed by a opening brace or parenthesis.  This is useful for
+     platforms where dollar signs are commonly used in names, such as
+     volume names and system directory names on VMS.
+     [Richard Levitte]
+
   *) Added functionality to create an EVP_PKEY from user data.  This
      is effectively the same as creating a RSA, DH or DSA object and
      then assigning them to an EVP_PKEY, but directly using algorithm

crypto/conf/conf_def.c

@@ -354,7 +354,49 @@ static int def_load_bio(CONF *conf, BIO *in, long *line)
                 psection = section;
             }
             p = eat_ws(conf, end);
-            if (strncmp(pname, ".include", 8) == 0
+            if (strncmp(pname, ".pragma", 7) == 0
+                && (p != pname + 7 || *p == '=')) {
+                char *pval;
+
+                if (*p == '=') {
+                    p++;
+                    p = eat_ws(conf, p);
+                }
+                trim_ws(conf, p);
+
+                /* Pragma values take the form keyword:value */
+                pval = strchr(p, ':');
+                if (pval == NULL || pval == p || pval[1] == '\0') {
+                    CONFerr(CONF_F_DEF_LOAD_BIO, CONF_R_INVALID_PRAGMA);
+                    goto err;
+                }
+
+                *pval++ = '\0';
+                trim_ws(conf, p);
+                pval = eat_ws(conf, pval);
+
+                /*
+                 * Known pragmas:
+                 *
+                 * dollarid     takes "on", "true or "off", "false"
+                 */
+                if (strcmp(p, "dollarid") == 0) {
+                    if (strcmp(pval, "on") == 0
+                        || strcmp(pval, "true") == 0) {
+                        conf->flag_dollarid = 1;
+                    } else if (strcmp(pval, "off") == 0
+                               || strcmp(pval, "false") == 0) {
+                        conf->flag_dollarid = 0;
+                    } else {
+                        CONFerr(CONF_F_DEF_LOAD_BIO, CONF_R_INVALID_PRAGMA);
+                        goto err;
+                    }
+                }
+                /*
+                 * We *ignore* any unknown pragma.
+                 */
+                continue;
+            } else if (strncmp(pname, ".include", 8) == 0
                 && (p != pname + 8 || *p == '=')) {
                 char *include = NULL;
                 BIO *next;
@@ -590,7 +632,10 @@ static int str_copy(CONF *conf, char *section, char **pto, char *from)
             buf->data[to++] = v;
         } else if (IS_EOF(conf, *from))
             break;
-        else if (*from == '$') {
+        else if (*from == '$'
+                 && (!conf->flag_dollarid
+                     || from[1] == '{'
+                     || from[1] == '(')) {
             size_t newsize;
 
             /* try to expand it */
@@ -607,7 +652,8 @@ static int str_copy(CONF *conf, char *section, char **pto, char *from)
                 s++;
             cp = section;
             e = np = s;
-            while (IS_ALNUM(conf, *e))
+            while (IS_ALNUM(conf, *e)
+                   || (conf->flag_dollarid && IS_DOLLAR(conf, *e)))
                 e++;
             if ((e[0] == ':') && (e[1] == ':')) {
                 cp = np;
@@ -616,7 +662,8 @@ static int str_copy(CONF *conf, char *section, char **pto, char *from)
                 *rrp = '\0';
                 e += 2;
                 np = e;
-                while (IS_ALNUM(conf, *e))
+                while (IS_ALNUM(conf, *e)
+                       || (conf->flag_dollarid && IS_DOLLAR(conf, *e)))
                     e++;
             }
             r = *e;
@@ -832,7 +879,8 @@ static char *eat_alpha_numeric(CONF *conf, char *p)
             p = scan_esc(conf, p);
             continue;
         }
-        if (!IS_ALNUM_PUNCT(conf, *p))
+        if (!(IS_ALNUM_PUNCT(conf, *p)
+              || (conf->flag_dollarid && IS_DOLLAR(conf, *p))))
             return p;
         p++;
     }

crypto/conf/conf_def.h

@@ -20,6 +20,7 @@
 #define CONF_DQUOTE       1024
 #define CONF_COMMENT      128
 #define CONF_FCOMMENT     2048
+#define CONF_DOLLAR       4096
 #define CONF_EOF          8
 #define CONF_ALPHA        (CONF_UPPER|CONF_LOWER)
 #define CONF_ALNUM        (CONF_ALPHA|CONF_NUMBER|CONF_UNDER)
@@ -36,13 +37,14 @@
 #define IS_ALNUM_PUNCT(conf,c) is_keytype(conf, c, CONF_ALNUM_PUNCT)
 #define IS_QUOTE(conf,c)       is_keytype(conf, c, CONF_QUOTE)
 #define IS_DQUOTE(conf,c)      is_keytype(conf, c, CONF_DQUOTE)
+#define IS_DOLLAR(conf,c)      is_keytype(conf, c, CONF_DOLLAR)
 
 static const unsigned short CONF_type_default[128] = {
     0x0008, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
     0x0000, 0x0010, 0x0010, 0x0000, 0x0000, 0x0010, 0x0000, 0x0000,
     0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
     0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-    0x0010, 0x0200, 0x0040, 0x0080, 0x0000, 0x0200, 0x0200, 0x0040,
+    0x0010, 0x0200, 0x0040, 0x0080, 0x1000, 0x0200, 0x0200, 0x0040,
     0x0000, 0x0000, 0x0200, 0x0200, 0x0200, 0x0200, 0x0200, 0x0200,
     0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001,
     0x0001, 0x0001, 0x0000, 0x0200, 0x0000, 0x0000, 0x0000, 0x0200,
@@ -62,7 +64,7 @@ static const unsigned short CONF_type_win32[128] = {
     0x0000, 0x0010, 0x0010, 0x0000, 0x0000, 0x0010, 0x0000, 0x0000,
     0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
     0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
-    0x0010, 0x0200, 0x0400, 0x0000, 0x0000, 0x0200, 0x0200, 0x0000,
+    0x0010, 0x0200, 0x0400, 0x0000, 0x1000, 0x0200, 0x0200, 0x0000,
     0x0000, 0x0000, 0x0200, 0x0200, 0x0200, 0x0200, 0x0200, 0x0200,
     0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001,
     0x0001, 0x0001, 0x0000, 0x0A00, 0x0000, 0x0000, 0x0000, 0x0200,

crypto/conf/conf_err.c

@@ -15,8 +15,11 @@
 
 static const ERR_STRING_DATA CONF_str_reasons[] = {
     {ERR_PACK(ERR_LIB_CONF, 0, CONF_R_ERROR_LOADING_DSO), "error loading dso"},
+    {ERR_PACK(ERR_LIB_CONF, 0, CONF_R_INVALID_PRAGMA), "invalid pragma"},
     {ERR_PACK(ERR_LIB_CONF, 0, CONF_R_LIST_CANNOT_BE_NULL),
     "list cannot be null"},
+    {ERR_PACK(ERR_LIB_CONF, 0, CONF_R_MANDATORY_BRACES_IN_VARIABLE_EXPANSION),
+    "mandatory braces in variable expansion"},
     {ERR_PACK(ERR_LIB_CONF, 0, CONF_R_MISSING_CLOSE_SQUARE_BRACKET),
     "missing close square bracket"},
     {ERR_PACK(ERR_LIB_CONF, 0, CONF_R_MISSING_EQUAL_SIGN),

crypto/conf/keysets.pl

@@ -20,6 +20,7 @@ my $QUOTE       = 0x0040;
 my $DQUOTE      = 0x0400;
 my $COMMENT     = 0x0080;
 my $FCOMMENT    = 0x0800;
+my $DOLLAR      = 0x1000;
 my $EOF         = 0x0008;
 my @V_def;
 my @V_w32;
@@ -38,6 +39,7 @@ foreach (0 .. 127) {
     $v |= $ESC         if $c =~ /\\/;
     $v |= $QUOTE       if $c =~ /['`"]/;         # for emacs: "`'
     $v |= $COMMENT     if $c =~ /\#/;
+    $v |= $DOLLAR      if $c eq '$';
     $v |= $EOF         if $c =~ /\0/;
     push(@V_def, $v);
 
@@ -50,6 +52,7 @@ foreach (0 .. 127) {
     $v |= $WS          if $c =~ /[ \t\r\n]/;
     $v |= $DQUOTE      if $c =~ /["]/;           # for emacs: "
     $v |= $FCOMMENT    if $c =~ /;/;
+    $v |= $DOLLAR      if $c eq '$';
     $v |= $EOF         if $c =~ /\0/;
     push(@V_w32, $v);
 }
@@ -80,6 +83,7 @@ print <<"EOF";
 #define CONF_DQUOTE       $DQUOTE
 #define CONF_COMMENT      $COMMENT
 #define CONF_FCOMMENT     $FCOMMENT
+#define CONF_DOLLAR       $DOLLAR
 #define CONF_EOF          $EOF
 #define CONF_ALPHA        (CONF_UPPER|CONF_LOWER)
 #define CONF_ALNUM        (CONF_ALPHA|CONF_NUMBER|CONF_UNDER)
@@ -96,6 +100,7 @@ print <<"EOF";
 #define IS_ALNUM_PUNCT(conf,c) is_keytype(conf, c, CONF_ALNUM_PUNCT)
 #define IS_QUOTE(conf,c)       is_keytype(conf, c, CONF_QUOTE)
 #define IS_DQUOTE(conf,c)      is_keytype(conf, c, CONF_DQUOTE)
+#define IS_DOLLAR(conf,c)      is_keytype(conf, c, CONF_DOLLAR)
 
 EOF
 

crypto/err/openssl.txt

@@ -2163,7 +2163,10 @@ COMP_R_ZLIB_DEFLATE_ERROR:99:zlib deflate error
 COMP_R_ZLIB_INFLATE_ERROR:100:zlib inflate error
 COMP_R_ZLIB_NOT_SUPPORTED:101:zlib not supported
 CONF_R_ERROR_LOADING_DSO:110:error loading dso
+CONF_R_INVALID_PRAGMA:122:invalid pragma
 CONF_R_LIST_CANNOT_BE_NULL:115:list cannot be null
+CONF_R_MANDATORY_BRACES_IN_VARIABLE_EXPANSION:123:\
+	mandatory braces in variable expansion
 CONF_R_MISSING_CLOSE_SQUARE_BRACKET:100:missing close square bracket
 CONF_R_MISSING_EQUAL_SIGN:101:missing equal sign
 CONF_R_MISSING_INIT_FUNCTION:112:missing init function

doc/man5/config.pod

@@ -50,6 +50,9 @@ not support the B<.include> syntax. They would bail out with error
 if the B<=> character is not present but with it they just ignore
 the include.
 
+Pragmas can be specified with the B<.pragma> directive.
+See L</PRAGMAS> for mor information.
+
 Each section in a configuration file consists of a number of name and
 value pairs of the form B<name=value>
 
@@ -78,6 +81,40 @@ the sequences B<\n>, B<\r>, B<\b> and B<\t> are recognized.
 All expansion and escape rules as described above that apply to B<value>
 also apply to the path of the B<.include> directive.
 
+=head1 PRAGMAS
+
+Pragmas can be used to change the behavior of the configuration file
+parser, among others.  Currently supported pragmas are:
+
+=over 4
+
+=item B<.pragma> B<dollarid>:I<value>
+
+I<value> can be one of:
+
+=over 4
+
+=item  B<"on"> or B<"true">
+
+this signifies that dollar signs are considered an identity character
+from this point on and that variable expansion requires the use of
+braces or parentheses.  In other words, C<foo$bar> will be considered
+a name instead of C<foo> followed by the expansion of the variable
+C<bar>.
+This is suitable for platforms where the dollar sign is commonly used
+as part of names.
+
+=item B<"off"> or B<"false">
+
+Turns this pragma off, i.e. C<foo$bar> will be interpreted as C<foo>
+followed by the expansion of the variable C<bar>.
+
+=back
+
+By default, this pragma is turned off.
+
+=back
+
 =head1 OPENSSL LIBRARY CONFIGURATION
 
 Applications can automatically configure certain

include/openssl/conf.h

@@ -110,6 +110,7 @@ struct conf_st {
     CONF_METHOD *meth;
     void *meth_data;
     LHASH_OF(CONF_VALUE) *data;
+    unsigned int flag_dollarid:1;
 };
 
 CONF *NCONF_new(CONF_METHOD *meth);

include/openssl/conferr.h

@@ -59,7 +59,9 @@ int ERR_load_CONF_strings(void);
  * CONF reason codes.
  */
 # define CONF_R_ERROR_LOADING_DSO                         110
+# define CONF_R_INVALID_PRAGMA                            122
 # define CONF_R_LIST_CANNOT_BE_NULL                       115
+# define CONF_R_MANDATORY_BRACES_IN_VARIABLE_EXPANSION    123
 # define CONF_R_MISSING_CLOSE_SQUARE_BRACKET              100
 # define CONF_R_MISSING_EQUAL_SIGN                        101
 # define CONF_R_MISSING_INIT_FUNCTION                     112