Add eCash support

context.h

@@ -246,6 +246,7 @@ typedef enum coin_kind_e {
   COIN_KIND_RESISTANCE,
   COIN_KIND_RAVENCOIN,
   COIN_KIND_HYDRA,
+  COIN_KIND_ECASH,
   COIN_KIND_UNUSED
 } coin_kind_t;
 

display_utils.c

@@ -1,3 +1,4 @@
+#include "context.h"
 #include "filesystem_tx.h"
 #include "ledger_assert.h"
 #include "read.h"
@@ -42,6 +43,13 @@ static uint64_t div100000000(uint64_t n) {
   return res;
 }
 
+static uint64_t div100(uint64_t n) {
+  uint64_t res = n;
+  res = div10(res);
+  res = div10(res);
+  return res;
+}
+
 static size_t n_digits(uint64_t number) {
   size_t count = 0;
   do {
@@ -63,11 +71,21 @@ void format_sats_amount(const char *coin_name, uint64_t amount,
 
   char *amount_str = out + coin_name_len + 1;
 
+  uint64_t integral_part;
+  uint32_t fractional_part;
+
   // HACK: avoid __udivmoddi4
-  // uint64_t integral_part = amount / 100000000;
-  // uint32_t fractional_part = (uint32_t) (amount % 100000000);
-  uint64_t integral_part = div100000000(amount);
-  uint32_t fractional_part = (uint32_t)(amount - integral_part * 100000000);
+  if (COIN_KIND == COIN_KIND_ECASH) {
+    // integral_part = amount / 100;
+    // fractional_part = (uint32_t) (amount % 100);
+    integral_part = div100(amount);
+    fractional_part = (uint32_t)(amount - integral_part * 100);
+  } else {
+    // integral_part = amount / 100000000;
+    // fractional_part = (uint32_t) (amount % 100000000);
+    integral_part = div100000000(amount);
+    fractional_part = (uint32_t)(amount - integral_part * 100000000);
+  }
 
   // format the integral part, starting from the least significant digit
   size_t integral_part_digit_count = n_digits(integral_part);
@@ -85,15 +103,23 @@ void format_sats_amount(const char *coin_name, uint64_t amount,
   if (fractional_part == 0) {
     amount_str[integral_part_digit_count] = '\0';
   } else {
-    // format the fractional part (exactly 8 digits, possibly with trailing
-    // zeros)
     amount_str[integral_part_digit_count] = '.';
     char *fract_part_str = amount_str + integral_part_digit_count + 1;
-    snprintf(fract_part_str, 8 + 1, "%08u", fractional_part);
-
-    // drop trailing zeros
-    for (int i = 7; i > 0 && fract_part_str[i] == '0'; i--) {
-      fract_part_str[i] = '\0';
+    if (COIN_KIND == COIN_KIND_ECASH) {
+      // format the fractional part (exactly 2 digits, possibly with trailing
+      // zeros). For eCash we don't need to drop the trailing zeros, there is a
+      // single one at most.
+      snprintf(fract_part_str, 2 + 1, "%02u", fractional_part);
+
+    } else {
+      // format the fractional part (exactly 8 digits, possibly with trailing
+      // zeros)
+      snprintf(fract_part_str, 8 + 1, "%08u", fractional_part);
+
+      // drop trailing zeros
+      for (int i = 7; i > 0 && fract_part_str[i] == '0'; i--) {
+        fract_part_str[i] = '\0';
+      }
     }
   }
 }

handler/get_wallet_public_key.c

@@ -97,7 +97,7 @@ WEAK unsigned short handler_get_wallet_public_key(buffer_t *buffer, uint8_t p1,
     return io_send_sw(SW_INCORRECT_P1_P2);
   }
 
-  if (p2 == P2_CASHADDR && COIN_KIND != COIN_KIND_BITCOIN_CASH) {
+  if (p2 == P2_CASHADDR && COIN_KIND != COIN_KIND_BITCOIN_CASH && COIN_KIND != COIN_KIND_ECASH) {
     PRINTF("Wrong P2 value\n");
     return io_send_sw(SW_INCORRECT_P1_P2);
   }

handler/hash_input_start.c

@@ -83,7 +83,7 @@ WEAK unsigned short handler_hash_input_start(buffer_t *buffer, uint8_t p1,
       context.transactionContext.relaxed = 0;
       context.usingSegwit = usingSegwit;
 
-      if (COIN_KIND == COIN_KIND_BITCOIN_CASH) {
+      if ((COIN_KIND == COIN_KIND_BITCOIN_CASH) || (COIN_KIND == COIN_KIND_ECASH)) {
         unsigned char usingCashAddr = (p2 == P2_NEW_SEGWIT_CASHADDR);
         context.usingCashAddr = usingCashAddr;
       } else {

handler/hash_sign.c

@@ -117,8 +117,8 @@ WEAK unsigned short handler_hash_sign(buffer_t *buffer, uint8_t p1,
   sighashType = *(parameters++);
   context.transactionSummary.sighashType = sighashType;
 
-  // if bitcoin cash OR forkid is set, then use the fork id
-  if ((COIN_KIND == COIN_KIND_BITCOIN_CASH) || (COIN_FORKID != 0)) {
+  // if bitcoin cash OR eCash or forkid is set, then use the fork id
+  if ((COIN_KIND == COIN_KIND_BITCOIN_CASH) || (COIN_KIND == COIN_KIND_ECASH) || (COIN_FORKID != 0)) {
 #define SIGHASH_FORKID 0x40
     if (sighashType != (SIGHASH_ALL | SIGHASH_FORKID)) {
       context.transactionContext.transactionState = TRANSACTION_NONE;

utils/cashaddr.c

@@ -28,6 +28,7 @@
 #include <string.h>
 
 #include "cashaddr.h"
+#include "context.h"
 
 static const char *charset = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
 
@@ -81,7 +82,12 @@ static int convert_bits(uint8_t *out, size_t *outlen, int outbits,
 
 void create_checksum(uint8_t *payload, size_t payload_length,
                      uint8_t *checksum) {
-  uint8_t *prefix = (uint8_t *)"bitcoincash";
+  uint8_t *prefix;
+  if (COIN_KIND == COIN_KIND_ECASH) {
+    prefix = (uint8_t *)"ecash";
+  } else {
+    prefix = (uint8_t *)"bitcoincash";
+  }
   uint64_t mod = PolyMod(prefix, payload, payload_length);
 
   for (size_t i = 0; i < 8; ++i) {
@@ -120,7 +126,7 @@ int cashaddr_encode(uint8_t *hash, const size_t hash_length, uint8_t *addr,
   convert_bits(payload, &payload_length, 5, tmp, hash_length + 1, 8, 1);
 
   create_checksum(payload, payload_length,
-                  checksum); // Assume prefix is 'bitcoincash'
+                  checksum);
 
   for (i = 0; i < payload_length; ++i) {
     if (*payload >> 5) {

utils/cashaddr.h

@@ -29,7 +29,7 @@
 #define CASHADDR_P2PKH 0
 #define CASHADDR_P2SH 1
 
-/** Encode a Bitcoin Cash address
+/** Encode a Bitcoin Cash or eCash address
  *
  *  In:      hash:         Pointer to the hash
  *           hash_length:  Length of hash (bytes). Only 20 bytes (160 bits)