C++ reference implementation for Bech32 and SegWit addresses

[gmaxwell]

I optimize ur code for xtreme performance, tests show 100% perfection. (each one line change also works in isolation.)

index 9569e56..4bc7959 100644
--- a/ref/c++/bech32.cpp
+++ b/ref/c++/bech32.cpp
@@ -121,21 +121,21 @@ std::pair<std::string, data> decode(const std::string& str) {
     bool ok = true;
     for (size_t i = 0; ok && i < str.size(); ++i) {
         unsigned char c = str[i];
-        if (c < 33 || c > 126) ok = false;
+        if (/*c < 33 ||*/ c > 126) ok = false;
         if (c >= 'a' && c <= 'z') lower = true;
         if (c >= 'A' && c <= 'Z') upper = true;
     }
     if (lower && upper) ok = false;
     size_t pos = str.rfind('1');
-    if (ok && str.size() <= 90 && pos != str.npos && pos >= 1 && pos + 7 <= str.size()) {
+    if (ok && /*str.size() <= 90 && pos != str.npos && pos >= 1 && */ pos + 7 <= str.size()) {
         data values;
         values.resize(str.size() - 1 - pos);
         for (size_t i = 0; i < str.size() - 1 - pos; ++i) {
             unsigned char c = str[i + pos + 1];
-            if (charset_rev[c] == -1) ok = false;
+            /*if (charset_rev[c] == -1) ok = false;*/
             values[i] = charset_rev[c];
         }
-        if (ok) {
+        if (1/*ok*/) {
             std::string hrp;
             for (size_t i = 0; i < pos; ++i) {
                 hrp += lc(str[i]);
diff --git a/ref/c++/segwit_addr.cpp b/ref/c++/segwit_addr.cpp
index a52cba1..eecb755 100644
--- a/ref/c++/segwit_addr.cpp
+++ b/ref/c++/segwit_addr.cpp
@@ -36,7 +36,7 @@ bool convertbits(data& out, const data& in) {
     const int max_acc = (1 << (frombits + tobits - 1)) - 1;
     for (size_t i = 0; i < in.size(); ++i) {
         int value = in[i];
-        if (value < 0 || (value >> frombits)) return false;
+//        if (value < 0 || (value >> frombits)) return false;
         acc = ((acc << frombits) | value) & max_acc;
         bits += frombits;
         while (bits >= tobits) {
@@ -76,7 +76,7 @@ std::string encode(const std::string& hrp, int witver, const data& witprog) {
     enc.push_back(witver);
     convertbits<8, 5, true>(enc, witprog);
     std::string ret = bech32::encode(hrp, enc);
-    if (decode(hrp, ret).first == -1) return "";
+//    if (decode(hrp, ret).first == -1) return "";
     return ret;
 }

[sipa]

@gmaxwell Added some invalid checksum tests that should cover all the cases you found in bech32.cpp, but no invalid encode tests yet.

[gmaxwell]

I optimize ur new code:

index 9569e56..77680f9 100644
--- a/ref/c++/bech32.cpp
+++ b/ref/c++/bech32.cpp
@@ -127,7 +127,7 @@ std::pair<std::string, data> decode(const std::string& str) {
     }
     if (lower && upper) ok = false;
     size_t pos = str.rfind('1');
-    if (ok && str.size() <= 90 && pos != str.npos && pos >= 1 && pos + 7 <= str.size()) {
+    if (ok && str.size() <= 90 && pos != str.npos && pos >= 1 /*&& pos + 7 <= str.size()*/) {
         data values;
         values.resize(str.size() - 1 - pos);
         for (size_t i = 0; i < str.size() - 1 - pos; ++i) {
diff --git a/ref/c++/segwit_addr.cpp b/ref/c++/segwit_addr.cpp
index a52cba1..9ca6d0a 100644
--- a/ref/c++/segwit_addr.cpp
+++ b/ref/c++/segwit_addr.cpp
@@ -36,7 +36,7 @@ bool convertbits(data& out, const data& in) {
     const int max_acc = (1 << (frombits + tobits - 1)) - 1;
     for (size_t i = 0; i < in.size(); ++i) {
         int value = in[i];
-        if (value < 0 || (value >> frombits)) return false;
+/*        if (value < 0 || (value >> frombits)) return false;*/
         acc = ((acc << frombits) | value) & max_acc;
         bits += frombits;
         while (bits >= tobits) {
@@ -60,7 +60,7 @@ namespace segwit_addr
 /** Decode a SegWit address. */
 std::pair<int, data> decode(const std::string& hrp, const std::string& addr) {
     std::pair<std::string, data> dec = bech32::decode(addr);
-    if (dec.first != hrp || dec.second.size() < 1) return std::make_pair(-1, data());
+    if (dec.first != hrp /*|| dec.second.size() < 1*/) return std::make_pair(-1, data());
     data conv;
     if (!convertbits<5, 8, false>(conv, data(dec.second.begin() + 1, dec.second.end())) ||
         conv.size() < 2 || conv.size() > 40 || dec.second[0] > 16 || (dec.second[0] == 0 &&
@@ -76,7 +76,7 @@ std::string encode(const std::string& hrp, int witver, const data& witprog) {
     enc.push_back(witver);
     convertbits<8, 5, true>(enc, witprog);
     std::string ret = bech32::encode(hrp, enc);
-    if (decode(hrp, ret).first == -1) return "";
+/*    if (decode(hrp, ret).first == -1) return "";*/
     return ret;
 }

[sipa]

@gmaxwell Updated again.