reveng add api RunModel

[proxmark3-svn] / client / cmdcrc.c

diff --git a/client/cmdcrc.c b/client/cmdcrc.c
index 82504db7a3ce29e92b353ddde165ef47cf64d3e8..f93ab99d178eab9d0f61e470aed0ad094293e71d 100644 (file)
--- a/client/cmdcrc.c
+++ b/client/cmdcrc.c
@@ -293,3 +293,126 @@ int CmdrevengTest(const char *Cmd){
        }
        return 1;
 }
+
+//-c || -v
+int RunModel(char *inModel, char *inHexStr, bool reverse, char *result){
+       /* default values */
+       static model_t model = {
+               PZERO,          // no CRC polynomial, user must specify
+               PZERO,          // Init = 0
+               P_BE,             // RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h
+               PZERO,          // XorOut = 0
+               PZERO,          // check value unused 
+               NULL              // no model name 
+       };
+       int ibperhx = 8, obperhx = 8;
+       int rflags = 0; // search flags 
+       int c;
+       unsigned long width = 0UL;
+       poly_t apoly, crc;
+
+       char *string;
+
+       // stdin must be binary
+       #ifdef _WIN32
+               _setmode(STDIN_FILENO, _O_BINARY);
+       #endif /* _WIN32 */
+
+       SETBMP();
+       //set model
+       if(!(c = mbynam(&model, inModel))) {
+               fprintf(stderr,"error: preset model '%s' not found.  Use reveng -D to list presets.\n", inModel);
+               return 0;
+       }
+       if(c < 0)
+               return uerr("no preset models available");
+
+       // must set width so that parameter to -ipx is not zeroed 
+       width = plen(model.spoly);
+       rflags |= R_HAVEP | R_HAVEI | R_HAVERI | R_HAVERO | R_HAVEX;
+       
+       mcanon(&model);
+
+       if (reverse) {
+               // v  calculate reversed CRC
+               /* Distinct from the -V switch as this causes
+                * the arguments and output to be reversed as well.
+                */
+               // reciprocate Poly
+               prcp(&model.spoly);
+
+               /* mrev() does:
+                *   if(refout) prev(init); else prev(xorout);
+                * but here the entire argument polynomial is
+                * reflected, not just the characters, so RefIn
+                * and RefOut are not inverted as with -V.
+                * Consequently Init is the mirror image of the
+                * one resulting from -V, and so we have:
+                */
+               if(~model.flags & P_REFOUT) {
+                       prev(&model.init);
+                       prev(&model.xorout);
+               }
+
+               // swap init and xorout
+               apoly = model.init;
+               model.init = model.xorout;
+               model.xorout = apoly;
+       }
+       // c  calculate CRC
+
+       // validate inputs
+       /* if(plen(model.spoly) == 0) {
+        *      fprintf(stderr,"%s: no polynomial specified for -%c (add -w WIDTH -p POLY)\n", myname, mode);
+        *      exit(EXIT_FAILURE);
+        * }
+        */
+
+       /* in the Williams model, xorout is applied after the refout stage.
+        * as refout is part of ptostr(), we reverse xorout here.
+        */
+       if(model.flags & P_REFOUT)
+               prev(&model.xorout);
+
+       apoly = strtop(inHexStr, model.flags, ibperhx);
+
+       if(reverse)
+               prev(&apoly);
+
+       crc = pcrc(apoly, model.spoly, model.init, model.xorout, model.flags);
+
+       if(reverse)
+               prev(&crc);
+
+       string = ptostr(crc, model.flags, obperhx);
+       for (int i = 0; i < 50; i++){
+               result[i] = string[i];
+               if (result[i]==0) break;
+       }
+       free(string);
+       pfree(&crc);
+       pfree(&apoly);
+       return 1;
+}
+
+//test call to RunModel
+int CmdrevengTestC(const char *Cmd){
+       int cmdp = 0;
+       char inModel[30] = {0x00};
+       char inHexStr[30] = {0x00};
+       char result[30];
+       int dataLen;
+
+       dataLen = param_getstr(Cmd, cmdp++, inModel);
+       if (dataLen < 4) return 0;
+       dataLen = param_getstr(Cmd, cmdp++, inHexStr);
+       if (dataLen < 4) return 0;
+       bool reverse = (param_get8(Cmd, cmdp)) ? true : false;
+
+       //PrintAndLog("mod: %s, hex: %s, rev %d", inModel, inHexStr, reverse);
+       int ans = RunModel(inModel, inHexStr, reverse, result);
+       if (!ans) return 0;
+       
+       PrintAndLog("Result: %s",result);
+       return 1;
+}