FIX: IV now is trunckated to 7bits in 'hf legic read,write, writeraw'

FIX: IV LSB bit is always set, in 'hf legic read,write, writeraw'

diff --git a/client/cmdhflegic.c b/client/cmdhflegic.c
index 39c64921fe509f62bd6eb0427aaddf6d45e71cfe..7b75f91c6f056e87ca59f4da7f6e6d3ed53c73b3 100644 (file)
--- a/client/cmdhflegic.c
+++ b/client/cmdhflegic.c
@@ -47,7 +47,7 @@ int usage_legic_read(void){
        PrintAndLog("  h             : this help");
        PrintAndLog("  <offset>      : offset in data array to start download from");
        PrintAndLog("  <length>      : number of bytes to download");
-       PrintAndLog("  <IV>          : (optional) Initialization vector to use");
+       PrintAndLog("  <IV>          : (optional) Initialization vector to use (ODD and 7bits)");
        PrintAndLog("");
        PrintAndLog("Samples:");
        PrintAndLog("      hf legic read");
@@ -65,7 +65,7 @@ int usage_legic_write(void){
        PrintAndLog("  h             : this help");
        PrintAndLog("  <offset>      : offset in data array to start writing from");
        PrintAndLog("  <length>      : number of bytes to write");
-       PrintAndLog("  <IV>          : (optional) Initialization vector to use");
+       PrintAndLog("  <IV>          : (optional) Initialization vector to use (ODD and 7bits)");
        PrintAndLog("");
        PrintAndLog("Samples:");
        PrintAndLog("      hf legic write");
@@ -79,7 +79,7 @@ int usage_legic_rawwrite(void){
        PrintAndLog("  h             : this help");
        PrintAndLog("  <address>     : address to write to");
        PrintAndLog("  <value>       : value to write");
-       PrintAndLog("  <IV>          : (optional) Initialization vector to use");
+       PrintAndLog("  <IV>          : (optional) Initialization vector to use (ODD and 7bits)");
        PrintAndLog("");
        PrintAndLog("Samples:");
        PrintAndLog("      hf legic writeraw");
@@ -101,12 +101,11 @@ int CmdLegicDecode(const char *Cmd) {
        int i = 0, k = 0, segmentNum = 0, segment_len = 0, segment_flag = 0;
        int crc = 0, wrp = 0, wrc = 0;
        uint8_t stamp_len = 0;
-       uint8_t data_buf[1052]; // receiver buffer
+       uint8_t data_buf[1024]; // receiver buffer
        char token_type[5] = {0,0,0,0,0};
        int dcf = 0;
        int bIsSegmented = 0;
 
-       // download EML memory, where the "legic read" command puts the data.
        // copy data from proxmark into buffer
        GetFromBigBuf(data_buf,sizeof(data_buf),0);
        if ( !WaitForResponseTimeout(CMD_ACK, NULL, 2000)){
@@ -388,13 +387,20 @@ int CmdLegicRFRead(const char *Cmd) {
        char cmdp = param_getchar(Cmd, 0);
        if ( cmdp == 'H' || cmdp == 'h' ) return usage_legic_read();
        
-       uint32_t offset = 0, len = 0, IV = 0;
+       uint32_t offset = 0, len = 0, IV = 1;
        sscanf(Cmd, "%x %x %x", &offset, &len, &IV);
 
        // OUT-OF-BOUNDS check
        if(len + offset > MAX_LENGTH) len = MAX_LENGTH - offset;
        
-       IV &= 0x7F;
+       if ( (IV & 0x7F) != IV ){
+               IV &= 0x7F;
+               PrintAndLog("Truncating IV to 7bits");
+       }
+       if ( (IV & 1) == 0 ){
+               IV |= 0x01;  // IV must be odd
+               PrintAndLog("LSB of IV must be SET");   
+       }
        PrintAndLog("Current IV: 0x%02x", IV);
        
        UsbCommand c= {CMD_READER_LEGIC_RF, {offset, len, IV}};
@@ -553,7 +559,7 @@ int CmdLegicRfWrite(const char *Cmd) {
        char cmdp = param_getchar(Cmd, 0);
        if ( cmdp == 'H' || cmdp == 'h' ) return usage_legic_write();
        
-       uint32_t offset = 0, len = 0, IV = SESSION_IV;
+       uint32_t offset = 0, len = 0, IV = 0;
        
     UsbCommand c = {CMD_WRITER_LEGIC_RF, {0,0,0}};
     int res = sscanf(Cmd, "%x %x %x", &offset, &len, &IV);
@@ -565,8 +571,15 @@ int CmdLegicRfWrite(const char *Cmd) {
        // OUT-OF-BOUNDS check
        if(len + offset > MAX_LENGTH) len = MAX_LENGTH - offset;
 
+       if ( (IV & 0x7F) != IV ){
+               IV &= 0x7F;
+               PrintAndLog("Truncating IV to 7bits");
+       }
+       if ( (IV & 1) == 0 ){
+               IV |= 0x01;  // IV must be odd
+               PrintAndLog("LSB of IV must be SET");   
+       }
        
-       IV &= 0x7F;
        PrintAndLog("Current IV: 0x%02x", IV);
        
        c.arg[0] = offset;
@@ -583,7 +596,7 @@ int CmdLegicRfRawWrite(const char *Cmd) {
        char cmdp = param_getchar(Cmd, 0);
        if ( cmdp == 'H' || cmdp == 'h' ) return usage_legic_rawwrite();
        
-       uint32_t address = 0, data = 0, IV = SESSION_IV;        
+       uint32_t address = 0, data = 0, IV = 0; 
        char answer;
 
     UsbCommand c = { CMD_RAW_WRITER_LEGIC_RF, {0,0,0} };
@@ -595,7 +608,14 @@ int CmdLegicRfRawWrite(const char *Cmd) {
        if(address > MAX_LENGTH)
                return usage_legic_rawwrite();
        
-       IV &= 0x7F;
+       if ( (IV & 0x7F) != IV ){
+               IV &= 0x7F;
+               PrintAndLog("Truncating IV to 7bits");
+       }
+       if ( (IV & 1) == 0 ){
+               IV |= 0x01;  // IV must be odd
+               PrintAndLog("LSB of IV must be SET");   
+       }
        PrintAndLog("Current IV: 0x%02x", IV);
 
        c.arg[0] = address;