Unification of the search descriptor usage.

1 files changed, 322 insertions, 0 deletions

diff --git a/common/userids.c b/common/userids.c
new file mode 100644
index 000000000..9a072dd80
--- /dev/null
+++ b/common/userids.c
@@ -0,0 +1,322 @@
+/* userids.c - Utility functions for user ids.
+ * Copyright (C) 2001, 2003, 2004, 2006,
+ *               2009 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* This file implements a few utility functions useful when working
+   with canonical encrypted S-expresions (i.e. not the S-exprssion
+   objects from libgcrypt).  */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util.h"
+#include "userids.h"
+
+
+/* Parse the user-id NAME and build a search description for it.
+ * Returns 0 on succdess or an error code.  DESC may be NULL to merely
+ * check the validity of a user-id.
+ *
+ * Some used rules:
+ * - If the username starts with 8,9,16 or 17 hex-digits (the first one
+ *   must be in the range 0..9), this is considered a keyid; depending
+ *   on the length a short or complete one.
+ * - If the username starts with 32,33,40 or 41 hex-digits (the first one
+ *   must be in the range 0..9), this is considered a fingerprint.
+ * - If the username starts with a left angle, we assume it is a complete
+ *   email address and look only at this part.
+ * - If the username starts with a colon we assume it is a unified 
+ *   key specfification. 
+ * - If the username starts with a '.', we assume it is the ending
+ *   part of an email address
+ * - If the username starts with an '@', we assume it is a part of an
+ *   email address
+ * - If the userid start with an '=' an exact compare is done.
+ * - If the userid starts with a '*' a case insensitive substring search is
+ *   done (This is the default).
+ * - If the userid starts with a '+' we will compare individual words
+ *   and a match requires that all the words are in the userid.
+ *   Words are delimited by white space or "()<>[]{}.@-+_,;/&!"
+ *   (note that you can't search for these characters). Compare
+ *   is not case sensitive.
+ * - If the userid starts with a '&' a 40 hex digits keygrip is expected.
+ */
+
+gpg_error_t
+classify_user_id (const char *name, KEYDB_SEARCH_DESC *desc)
+{
+  const char *s;
+  int hexprefix = 0;
+  int hexlength;
+  int mode = 0;   
+  KEYDB_SEARCH_DESC dummy_desc;
+
+  if (!desc)
+    desc = &dummy_desc;
+    
+  /* Clear the structure so that the mode field is set to zero unless
+     we set it to the correct value right at the end of this
+     function. */
+  memset (desc, 0, sizeof *desc);
+
+  /* Skip leading spaces.  */
+  for(s = name; *s && spacep (s); s++ )
+    ;
+
+  switch (*s) 
+    {
+    case 0:  /* Empty string is an error.  */
+      return gpg_error (GPG_ERR_INV_USER_ID);
+
+    case '.': /* An email address, compare from end.  Note that this
+                 has not yet been implemented in the search code.  */
+      mode = KEYDB_SEARCH_MODE_MAILEND;
+      s++;
+      desc->u.name = s;
+      break;
+
+    case '<': /* An email address.  */
+      mode = KEYDB_SEARCH_MODE_MAIL;
+      s++;
+      desc->u.name = s;
+      break;
+
+    case '@':  /* Part of an email address.  */
+      mode = KEYDB_SEARCH_MODE_MAILSUB;
+      s++;
+      desc->u.name = s;
+      break;
+
+    case '=':  /* Exact compare.  */
+      mode = KEYDB_SEARCH_MODE_EXACT;
+      s++;
+      desc->u.name = s;
+      break;
+
+    case '*':  /* Case insensitive substring search.  */
+      mode = KEYDB_SEARCH_MODE_SUBSTR;
+      s++;
+      desc->u.name = s;
+      break;
+
+    case '+':  /* Compare individual words.  Note that this has not
+                  yet been implemented in the search code.  */
+      mode = KEYDB_SEARCH_MODE_WORDS;
+      s++;
+      desc->u.name = s;
+      break;
+
+    case '/': /* Subject's DN.  */
+      s++;
+      if (!*s || spacep (s)) /* No DN or prefixed with a space.  */
+        return gpg_error (GPG_ERR_INV_USER_ID);
+      desc->u.name = s;
+      mode = KEYDB_SEARCH_MODE_SUBJECT;
+      break;
+
+    case '#': /* S/N with optional issuer id or just issuer id.  */
+      { 
+        const char *si;
+        
+        s++;
+        if ( *s == '/')
+          { /* "#/" indicates an issuer's DN.  */
+            s++;
+            if (!*s || spacep (s)) /* No DN or prefixed with a space.  */
+              return gpg_error (GPG_ERR_INV_USER_ID); 
+            desc->u.name = s;
+            mode = KEYDB_SEARCH_MODE_ISSUER;
+          }
+        else 
+          { /* Serialnumber + optional issuer ID.  */
+            for (si=s; *si && *si != '/'; si++)
+              {
+                 /* Check for an invalid digit in the serial number. */
+                if (!strchr("01234567890abcdefABCDEF", *si))
+                  return gpg_error (GPG_ERR_INV_USER_ID);
+              }
+            desc->sn = (const unsigned char*)s;
+            desc->snlen = -1;
+            if (!*si)
+              mode = KEYDB_SEARCH_MODE_SN;
+            else
+              {
+                s = si+1;
+                if (!*s || spacep (s))  /* No DN or prefixed with a space.  */
+                  return gpg_error (GPG_ERR_INV_USER_ID);
+                desc->u.name = s;
+                mode = KEYDB_SEARCH_MODE_ISSUER_SN;
+              }
+          }
+      }
+      break;
+
+    case ':': /* Unified fingerprint. */
+      {  
+        const char *se, *si;
+        int i;
+        
+        se = strchr (++s,':');
+        if (!se)
+          return gpg_error (GPG_ERR_INV_USER_ID);
+        for (i=0,si=s; si < se; si++, i++ )
+          {
+            if (!strchr("01234567890abcdefABCDEF", *si))
+              return gpg_error (GPG_ERR_INV_USER_ID); /* Invalid digit.  */
+          }
+        if (i != 32 && i != 40)
+          return gpg_error (GPG_ERR_INV_USER_ID); /* Invalid length of fpr.  */
+        for (i=0,si=s; si < se; i++, si +=2) 
+          desc->u.fpr[i] = hextobyte(si);
+        for (; i < 20; i++)
+          desc->u.fpr[i]= 0;
+        s = se + 1;
+        mode = KEYDB_SEARCH_MODE_FPR;
+      } 
+      break;
+
+    case '&': /* Keygrip*/
+      {  
+        if (hex2bin (s+1, desc->u.grip, 20) < 0)
+          return gpg_error (GPG_ERR_INV_USER_ID); /* Invalid. */
+        mode = KEYDB_SEARCH_MODE_KEYGRIP;
+      } 
+      break;
+
+    default:
+      if (s[0] == '0' && s[1] == 'x')
+        {
+          hexprefix = 1;
+          s += 2;
+        }
+
+      hexlength = strspn(s, "0123456789abcdefABCDEF");
+      if (hexlength >= 8 && s[hexlength] =='!')
+        {
+          desc->exact = 1;
+          hexlength++; /* Just for the following check.  */
+        }
+      
+      /* Check if a hexadecimal number is terminated by EOS or blank.  */
+      if (hexlength && s[hexlength] && !spacep (s+hexlength)) 
+        {
+          if (hexprefix) /* A "0x" prefix without a correct
+                            termination is an error.  */
+            return gpg_error (GPG_ERR_INV_USER_ID); 
+          /* The first characters looked like a hex number, but the
+             entire string is not.  */
+          hexlength = 0;  
+        }
+      
+      if (desc->exact)
+        hexlength--; /* Remove the bang.  */
+
+      if (hexlength == 8
+          || (!hexprefix && hexlength == 9 && *s == '0'))
+        { 
+          /* Short keyid.  */
+          if (hexlength == 9)
+            s++; 
+          desc->u.kid[1] = strtoul( s, NULL, 16 );
+          mode = KEYDB_SEARCH_MODE_SHORT_KID;
+        }
+      else if (hexlength == 16
+               || (!hexprefix && hexlength == 17 && *s == '0'))
+        { 
+          /* Long keyid.  */
+          char buf[9];
+          if (hexlength == 17)
+            s++;
+          mem2str (buf, s, 9);
+          desc->u.kid[0] = strtoul (buf, NULL, 16);
+          desc->u.kid[1] = strtoul (s+8, NULL, 16);
+          mode = KEYDB_SEARCH_MODE_LONG_KID;
+        }
+      else if (hexlength == 32
+               || (!hexprefix && hexlength == 33 && *s == '0'))
+        { 
+          /* MD5 fingerprint.  */
+          int i;
+          if (hexlength == 33)
+            s++;
+          memset (desc->u.fpr+16, 0, 4); 
+          for (i=0; i < 16; i++, s+=2) 
+            {
+              int c = hextobyte(s);
+              if (c == -1)
+                return gpg_error (GPG_ERR_INV_USER_ID);
+              desc->u.fpr[i] = c;
+            }
+          mode = KEYDB_SEARCH_MODE_FPR16;
+        }
+      else if (hexlength == 40
+               || (!hexprefix && hexlength == 41 && *s == '0'))
+        { 
+          /* SHA1/RMD160 fingerprint.  */
+          int i;
+          if (hexlength == 41)
+            s++;
+          for (i=0; i < 20; i++, s+=2) 
+            {
+              int c = hextobyte(s);
+              if (c == -1)
+                return gpg_error (GPG_ERR_INV_USER_ID);
+              desc->u.fpr[i] = c;
+            }
+          mode = KEYDB_SEARCH_MODE_FPR20;
+        }
+      else if (!hexprefix)
+        { 
+          /* The fingerprint in an X.509 listing is often delimited by
+             colons, so we try to single this case out. */
+          mode = 0;
+          hexlength = strspn (s, ":0123456789abcdefABCDEF");
+          if (hexlength == 59 && (!s[hexlength] || spacep (s+hexlength))) 
+            {
+              int i;
+
+              for (i=0; i < 20; i++, s += 3) 
+                {
+                  int c = hextobyte(s);
+                  if (c == -1 || (i < 19 && s[2] != ':'))
+                    break;
+                  desc->u.fpr[i] = c;
+                }
+              if (i == 20)
+                mode = KEYDB_SEARCH_MODE_FPR20;
+            }
+          if (!mode) /* Default to substring search.  */
+            { 
+              desc->exact = 0;
+              desc->u.name = s;
+              mode = KEYDB_SEARCH_MODE_SUBSTR; 
+            }
+        }
+      else
+	{ 
+          /* Hex number with a prefix but with a wrong length.  */
+          return gpg_error (GPG_ERR_INV_USER_ID);
+        }
+    }
+  
+  desc->mode = mode;
+  return 0;
+}