From: marshmellow42 Date: Tue, 21 Mar 2017 07:26:26 +0000 (-0400) Subject: add bitswap option for lf em 4x05write (#236) X-Git-Tag: v3.0.0~47 X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/2d42ea1e4dfb86bd9a68bf46354f03a990f85fed add bitswap option for lf em 4x05write (#236) default read mode of this chip outputs in reverse order... so offer the option to program in reverse order --- diff --git a/client/cmdlfem4x.c b/client/cmdlfem4x.c index d2ccfae8..6a076e33 100644 --- a/client/cmdlfem4x.c +++ b/client/cmdlfem4x.c @@ -763,9 +763,10 @@ int CmdEM4x05dump(const char *Cmd) { int usage_lf_em_write(void) { PrintAndLog("Write EM4x05/EM4x69. Tag must be on antenna. "); PrintAndLog(""); - PrintAndLog("Usage: lf em 4x05writeword [h]
"); + PrintAndLog("Usage: lf em 4x05writeword [h] [s]
"); PrintAndLog("Options:"); PrintAndLog(" h - this help"); + PrintAndLog(" s - swap data bit order before write"); PrintAndLog(" address - memory address to write to. (0-15)"); PrintAndLog(" data - data to write (hex)"); PrintAndLog(" pwd - password (hex) (optional)"); @@ -778,18 +779,23 @@ int usage_lf_em_write(void) { int CmdEM4x05WriteWord(const char *Cmd) { uint8_t ctmp = param_getchar(Cmd, 0); if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_write(); - + bool usePwd = false; - + uint8_t addr = 16; // default to invalid address uint32_t data = 0xFFFFFFFF; // default to blank data uint32_t pwd = 0xFFFFFFFF; // default to blank password - - addr = param_get8ex(Cmd, 0, 16, 10); - data = param_get32ex(Cmd, 1, 0, 16); - pwd = param_get32ex(Cmd, 2, 1, 16); - - + char swap = 0; + + int p = 0; + swap = param_getchar(Cmd, 0); + if (swap == 's' || swap=='S') p++; + addr = param_get8ex(Cmd, p++, 16, 10); + data = param_get32ex(Cmd, p++, 0, 16); + pwd = param_get32ex(Cmd, p++, 1, 16); + + if (swap == 's' || swap=='S') data = SwapBits(data, 32); + if ( (addr > 15) ) { PrintAndLog("Address must be between 0 and 15"); return 1; @@ -798,15 +804,15 @@ int CmdEM4x05WriteWord(const char *Cmd) { PrintAndLog("Writing address %d data %08X", addr, data); else { usePwd = true; - PrintAndLog("Writing address %d data %08X using password %08X", addr, data, pwd); + PrintAndLog("Writing address %d data %08X using password %08X", addr, data, pwd); } - + uint16_t flag = (addr << 8 ) | usePwd; - + UsbCommand c = {CMD_EM4X_WRITE_WORD, {flag, data, pwd}}; clearCommandBuffer(); SendCommand(&c); - UsbCommand resp; + UsbCommand resp; if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)){ PrintAndLog("Error occurred, device did not respond during write operation."); return -1; @@ -814,7 +820,7 @@ int CmdEM4x05WriteWord(const char *Cmd) { if ( !downloadSamplesEM() ) { return -1; } - //check response for 00001010 for write confirmation! + //check response for 00001010 for write confirmation! //attempt demod: uint32_t dummy = 0; int result = demodEM4x05resp(&dummy,false); diff --git a/client/util.c b/client/util.c index 81b2d844..7c70d55d 100644 --- a/client/util.c +++ b/client/util.c @@ -257,6 +257,15 @@ void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest) { } } +// Swap bit order on a uint32_t value. Can be limited by nrbits just use say 8bits reversal +// And clears the rest of the bits. +uint32_t SwapBits(uint32_t value, int nrbits) { + uint32_t newvalue = 0; + for(int i = 0; i < nrbits; i++) { + newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i); + } + return newvalue; +} // aa,bb,cc,dd,ee,ff,gg,hh, ii,jj,kk,ll,mm,nn,oo,pp // to diff --git a/client/util.h b/client/util.h index 1739498e..27f9348e 100644 --- a/client/util.h +++ b/client/util.h @@ -47,6 +47,7 @@ extern uint64_t bytes_to_num(uint8_t* src, size_t len); extern void num_to_bytebits(uint64_t n, size_t len, uint8_t *dest); extern void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest); extern char *printBits(size_t const size, void const * const ptr); +extern uint32_t SwapBits(uint32_t value, int nrbits); extern uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockSize); extern void SwapEndian64ex(const uint8_t *src, const size_t len, const uint8_t blockSize, uint8_t *dest);