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-rw-r--r--openpicc/application/iso14443a_diffmiller.c267
-rw-r--r--openpicc/application/tc_sniffer.c5
2 files changed, 137 insertions, 135 deletions
diff --git a/openpicc/application/iso14443a_diffmiller.c b/openpicc/application/iso14443a_diffmiller.c
index 020760f..cc895df 100644
--- a/openpicc/application/iso14443a_diffmiller.c
+++ b/openpicc/application/iso14443a_diffmiller.c
@@ -36,22 +36,6 @@
#define DEBUGP (void)
#define printf usb_print_string
-struct diffmiller_state {
- int initialized, pauses_count;
- iso14443_frame *frame;
- u_int32_t counter;
- u_int16_t byte,crc;
- u_int8_t parity;
- struct {
- u_int8_t in_frame:1;
- u_int8_t frame_finished:1;
- u_int8_t overflow:1;
- u_int8_t error:1;
- } flags;
-};
-
-struct diffmiller_state _state;
-
/*
* Decoding Methodology: We'll only see the edges for the start of modulation pauses and not
* all symbols generate modulation pauses at all. Two phases:
@@ -108,26 +92,24 @@ struct diffmiller_state _state;
enum symbol {NO_SYM=0, sym_x, sym_y, sym_z};
enum bit { BIT_ERROR, BIT_SOF, BIT_0, BIT_1, BIT_EOF };
-enum bit_length { out_of_range=0, len_3=1, len_5=2, len_7=3, len_9_or_greater=4 };
-const char *bit_length_descriptions[] = {
- [out_of_range] = "OOR",
- [len_3] = "3/4",
- [len_5] = "5/4",
- [len_7] = "7/4",
- [len_9_or_greater] = ">=9/4",
-};
-#define NIENTE {NO_SYM, NO_SYM}
-
-struct decoder_table_entry { enum symbol first, second; };
-const struct decoder_table_entry decoder_table[][5] = {
- /* out_of_range len_3 len_5 len_7 len_9_or_greater*/
- [NO_SYM] = {NIENTE, {sym_z, sym_z}, {sym_z, sym_x}, },
- [sym_x] = {NIENTE, {sym_x, NO_SYM}, {sym_y, sym_z}, {sym_y, sym_x}, {sym_y, sym_y}, },
- [sym_y] = {NIENTE, {sym_z, sym_z}, {sym_z, sym_x}, },
- [sym_z] = {NIENTE, {sym_z, NO_SYM}, {sym_x, NO_SYM}, {sym_y, NO_SYM}, {sym_y, NO_SYM}, },
+
+struct diffmiller_state {
+ int initialized, pauses_count;
+ enum symbol old_state;
+ enum bit last_bit;
+ iso14443_frame *frame;
+ u_int32_t counter;
+ u_int16_t byte,crc;
+ u_int8_t parity;
+ struct {
+ u_int8_t in_frame:1;
+ u_int8_t frame_finished:1;
+ u_int8_t overflow:1;
+ u_int8_t error:1;
+ } flags;
};
-int print_bits = 0;
+struct diffmiller_state _state;
inline void start_frame(struct diffmiller_state * const state)
{
@@ -141,8 +123,7 @@ inline void start_frame(struct diffmiller_state * const state)
state->flags.in_frame = 1;
//memset(state->frame, 0, sizeof(*state->frame));
- //memset(state->frame, 0, (u_int32_t)&(((iso14443_frame*)0)->data) );
- memset(state->frame, 0, 26 );
+ memset(state->frame, 0, (u_int32_t)&(((iso14443_frame*)0)->data) );
performance_set_checkpoint("start_frame after memset");
}
@@ -187,34 +168,8 @@ static inline void end_frame(struct diffmiller_state * const state)
}
}
-static inline void Miller_Bit(struct diffmiller_state * const state, const enum bit bit)
+static inline void Miller_Bit(struct diffmiller_state * const state, const int bit_value)
{
- switch(bit) {
- case BIT_SOF:
- if(print_bits) printf("SOF");
- start_frame(state);
- break;
- case BIT_0:
- if(print_bits) printf(" 0");
- break;
- case BIT_1:
- if(print_bits) printf(" 1");
- break;
- case BIT_EOF:
- if(print_bits) printf(" EOF\n");
- end_frame(state);
- break;
- default:
- if(print_bits) printf(" ERROR\n");
- state->flags.error = 1;
- end_frame(state);
- break;
- }
-
- int bit_value;
- if(bit==BIT_0) bit_value = 0;
- else if(bit==BIT_1) bit_value = 1;
- else return;
if(state->counter<8) {
state->byte=state->byte | (bit_value<<state->counter);
@@ -239,82 +194,64 @@ static inline void Miller_Bit(struct diffmiller_state * const state, const enum
}
}
-static inline void Miller_Symbol(struct diffmiller_state * const state, const enum symbol symbol)
-{
- static enum bit last_bit = BIT_ERROR;
- static int in_frame = 0;
- enum bit bit = BIT_ERROR;
-
- //DEBUGP("%c ", 'X'+(symbol-1));
- if(!in_frame) {
- if(symbol == sym_z)
- bit = BIT_SOF;
- else
- bit = BIT_ERROR;
- } else {
- switch(symbol) {
- case sym_y:
- if(last_bit == BIT_0)
- bit = BIT_EOF;
- else
- bit = BIT_0;
- break;
- case sym_x:
- bit = BIT_1;
- break;
- case sym_z:
- bit = BIT_0;
- break;
- default:
- bit = BIT_ERROR;
- break;
- }
+#define PRINT_BIT(a) if(0){(void)a;}
+//#define PRINT_BIT(a) usb_print_string(a)
+
+#define DO_BIT_0 { \
+ Miller_Bit(state, 0); \
+ PRINT_BIT(" 0"); \
}
-
- if(bit != BIT_EOF && last_bit == BIT_0)
- Miller_Bit(state, last_bit);
- if(bit != BIT_0) Miller_Bit(state, bit);
-
- last_bit = bit;
- if(bit==BIT_SOF) {
- in_frame = 1;
- last_bit = BIT_ERROR;
- } else if(bit==BIT_EOF || bit==BIT_ERROR) {
- in_frame = 0;
+
+#define DO_BIT_1 { \
+ Miller_Bit(state, 1); \
+ PRINT_BIT(" 1"); \
}
-
-}
-static inline void Miller_Edge(struct diffmiller_state * const state, const unsigned int delta)
-{
- static enum symbol old_state = NO_SYM;
- enum bit_length length = out_of_range;
-
- if( ALMOST_EQUAL(delta, BIT_LEN_3) ) {
- length = len_3;
- } else if( ALMOST_EQUAL(delta, BIT_LEN_5) ) {
- length = len_5;
- } else if( ALMOST_EQUAL(delta, BIT_LEN_7) ) {
- length = len_7;
- } else if( ALMOST_GREATER_THAN_OR_EQUAL(delta, BIT_LEN_9)) {
- length = len_9_or_greater;
+#define DO_SYMBOL_X \
+ if(!in_frame) { \
+ if(last_bit == BIT_0) DO_BIT_0; \
+ error = 1; \
+ end_frame(state); \
+ PRINT_BIT(" ERROR\n"); \
+ last_bit = BIT_ERROR; \
+ in_frame = 0; \
+ } else { \
+ if(last_bit == BIT_0) DO_BIT_0; \
+ DO_BIT_1; \
+ last_bit = BIT_1; \
}
-
- const struct decoder_table_entry *entry;
- entry = &decoder_table[old_state][length];
- //DEBUGP(" %c{%i}[%s]", 'X'-sym_x+old_state, delta, bit_length_descriptions[length]);
- if(entry->first != NO_SYM) {
- //DEBUGP("%c ", 'X'-sym_x+entry->first);
- Miller_Symbol(state, old_state = entry->first);
- } else {
- DEBUGP("! ");
+
+#define DO_SYMBOL_Y \
+ if(!in_frame) { \
+ if(last_bit == BIT_0) DO_BIT_0; \
+ error = 1; \
+ end_frame(state); \
+ PRINT_BIT(" ERROR\n"); \
+ last_bit = BIT_ERROR; \
+ in_frame = 0; \
+ } else { \
+ if(last_bit == BIT_0) { \
+ end_frame(state); \
+ PRINT_BIT(" EOF\n"); \
+ last_bit = BIT_EOF; \
+ in_frame = 0; \
+ } else { \
+ last_bit = BIT_0; \
+ } \
}
-
- if(entry->second != NO_SYM) {
- //DEBUGP("%c ", 'X'-sym_x+entry->second);
- Miller_Symbol(state, old_state = entry->second);
+
+#define DO_SYMBOL_Z \
+ if(!in_frame) { \
+ if(last_bit == BIT_0) DO_BIT_0; \
+ start_frame(state); \
+ PRINT_BIT("SOF"); \
+ in_frame = 1; \
+ last_bit = BIT_ERROR; \
+ last_bit = BIT_SOF; \
+ } else { \
+ if(last_bit == BIT_0) DO_BIT_0; \
+ last_bit = BIT_0; \
}
-}
int iso14443a_decode_diffmiller(struct diffmiller_state * const state, iso14443_frame * const frame,
@@ -324,19 +261,79 @@ int iso14443a_decode_diffmiller(struct diffmiller_state * const state, iso14443_
if(state->frame != NULL && state->frame != frame) return -EINVAL;
state->frame = frame;
+ enum symbol old_state = state->old_state;
+ enum bit last_bit = state->last_bit;
+ int in_frame = state->flags.in_frame;
+ int error = state->flags.error;
+
for(; *offset < buflen; ) {
+ int delta;
if(state->pauses_count)
- Miller_Edge(state, buffer[(*offset)++] - PAUSE_LEN);
+ delta = buffer[(*offset)++] - PAUSE_LEN;
else
- Miller_Edge(state, buffer[(*offset)++]);
+ delta = buffer[(*offset)++];
+
+ switch(old_state) {
+ case sym_x:
+ if( ALMOST_EQUAL(delta, BIT_LEN_3) ) {
+ DO_SYMBOL_X;
+ old_state = sym_x;
+ } else if( ALMOST_EQUAL(delta, BIT_LEN_5) ) {
+ DO_SYMBOL_Y;
+ DO_SYMBOL_Z;
+ old_state = sym_z;
+ } else if( ALMOST_EQUAL(delta, BIT_LEN_7) ) {
+ DO_SYMBOL_Y;
+ DO_SYMBOL_X;
+ old_state = sym_x;
+ } else if( ALMOST_GREATER_THAN_OR_EQUAL(delta, BIT_LEN_9)) {
+ DO_SYMBOL_Y;
+ DO_SYMBOL_Y;
+ old_state = sym_y;
+ }
+ break;
+ case NO_SYM: /* Fall-Through */
+ case sym_y:
+ if( ALMOST_EQUAL(delta, BIT_LEN_3) ) {
+ DO_SYMBOL_Z;
+ DO_SYMBOL_Z;
+ old_state = sym_z;
+ } else if( ALMOST_EQUAL(delta, BIT_LEN_5) ) {
+ DO_SYMBOL_Z;
+ DO_SYMBOL_X;
+ old_state = sym_x;
+ }
+ break;
+ case sym_z:
+ if( ALMOST_EQUAL(delta, BIT_LEN_3) ) {
+ DO_SYMBOL_Z;
+ old_state = sym_z;
+ } else if( ALMOST_EQUAL(delta, BIT_LEN_5) ) {
+ DO_SYMBOL_X;
+ old_state = sym_x;
+ } else if( ALMOST_GREATER_THAN_OR_EQUAL(delta, BIT_LEN_7)) {
+ DO_SYMBOL_Y;
+ old_state = sym_y;
+ }
+ break;
+ }
if(state->flags.frame_finished) {
state->flags.frame_finished = 0;
+ state->old_state = old_state;
+ state->last_bit = last_bit;
+ state->flags.in_frame = in_frame;
+ state->flags.error = error;
performance_set_checkpoint("frame finished");
return 0;
}
}
+ state->old_state = old_state;
+ state->last_bit = last_bit;
+ state->flags.in_frame = in_frame;
+ state->flags.error = error;
+
return -EBUSY;
}
diff --git a/openpicc/application/tc_sniffer.c b/openpicc/application/tc_sniffer.c
index cc21a2f..943a2ad 100644
--- a/openpicc/application/tc_sniffer.c
+++ b/openpicc/application/tc_sniffer.c
@@ -191,6 +191,11 @@ static void timing_loop(void)
performance_set_checkpoint("end of first buffer");
handle_buffer(testdata2, sizeof(testdata2)/sizeof(testdata2[0]));
performance_stop_report();
+ DumpStringToUSB("Produced frame of "); DumpUIntToUSB(rx_frame.numbytes);
+ DumpStringToUSB(" bytes and "); DumpUIntToUSB(rx_frame.numbits);
+ DumpStringToUSB(" bits: "); DumpBufferToUSB((char*)rx_frame.data, rx_frame.numbytes + (rx_frame.numbits+7)/8 );
+ DumpStringToUSB(" CRC "); if(rx_frame.parameters.a.crc) DumpStringToUSB("OK"); else DumpStringToUSB("ERROR");
+ DumpStringToUSB("\n\r");
}
}
personal git repositories of Harald Welte. Your mileage may vary