nevent/nprofile

Author: hoytech

src/apps/web/Bech32Utils.h

@@ -41,15 +41,51 @@ inline std::string encodeBech32Simple(const std::string &hrp, std::string_view v
     return bech32::encode(hrp, values5, bech32::Encoding::BECH32);
 }
 
-inline std::string decodeBech32Simple(std::string_view v) {
+inline std::string decodeBech32Raw(std::string_view v) {
     auto res = bech32::decode(std::string(v));
 
     if (res.encoding == bech32::Encoding::INVALID) throw herr("invalid bech32");
     else if (res.encoding == bech32::Encoding::BECH32M) throw herr("got bech32m");
 
     std::vector<uint8_t> out;
     if (!convertbits<5, 8, false>(out, res.data)) throw herr("convertbits failed");
-    if (out.size() != 32) throw herr("unexpected size from bech32");
 
     return std::string((char*)out.data(), out.size());
 }
+
+inline std::string decodeBech32Simple(std::string_view v) {
+    auto out = decodeBech32Raw(v);
+    if (out.size() != 32) throw herr("unexpected size from bech32");
+    return out;
+}
+
+inline uint8_t getByte(std::string_view &encoded) {
+    if (encoded.size() < 1) throw herr("parse ends prematurely");
+    uint8_t output = encoded[0];
+    encoded = encoded.substr(1);
+    return output;
+}
+
+inline std::string getBytes(std::string_view &encoded, size_t n) {
+    if (encoded.size() < n) throw herr("parse ends prematurely");
+    auto res = encoded.substr(0, n);
+    encoded = encoded.substr(n);
+    return std::string(res);
+};
+
+inline std::string decodeBech32GetSpecial(std::string_view origStr) {
+    auto decoded = decodeBech32Raw(origStr);
+    std::string_view s(decoded);
+
+    while (s.size()) {
+        auto tag = getByte(s);
+        auto len = getByte(s);
+        auto val = getBytes(s, len);
+        if (tag == 0) {
+            if (len != 32) throw herr("unexpected size from bech32 special");
+            return std::string(val);
+        }
+    }
+
+    throw herr("no special tag found");
+}

src/apps/web/TODO

@@ -1,7 +1,4 @@
 read
-  * support nprofile/nevent/etc links
-    example nevent: https://oddbean.com/e/note1qmye0at28we63aze93xjr92nzw725td0a5ncz3htwlc3wg78kp6q7802ad
-    example nprofile: https://oddbean.com/e/note1ykjalrpaj6jvxeuc434yd7ksrj8yd2vte478700ta8np250l3clsyjvh4q
   * non-500 error pages when bech32 fails to parse, for example
   * search field: enter anything, pubkey (hex or npub), eventId, etc. maybe even full-text search?
   * rss

src/apps/web/WebData.h

@@ -337,7 +337,7 @@ struct Event {
     }
 
     void preprocessEventContent(lmdb::txn &txn, Decompressor &decomp, UserCache &userCache, std::string &content, bool withLinks = true) const {
-        static RE2 matcher(R"((?is)(.*?)(https?://\S+|#\[\d+\]|nostr:(?:note|npub)1\w+))");
+        static RE2 matcher(R"((?is)(.*?)(https?://\S+|#\[\d+\]|nostr:(?:note|npub|nevent|nprofile)1\w+))");
 
         std::string output;
 
@@ -367,16 +367,38 @@ struct Event {
                 std::string path = "/e/";
                 path += sv(match).substr(6);
                 appendLink(path, sv(match));
+            } else if (match.starts_with("nostr:nevent1")) {
+                bool didTransform = false;
+
+                try {
+                    auto id = decodeBech32GetSpecial(sv(match).substr(6));
+                    std::string path = "/e/";
+                    path += encodeBech32Simple("note", id);
+
+                    appendLink(path, sv(match));
+                    didTransform = true;
+                } catch(...) {}
+
+                if (!didTransform) output += sv(match);
             } else if (match.starts_with("nostr:npub1")) {
                 bool didTransform = false;
 
                 try {
                     const auto *u = userCache.getUser(txn, decomp, decodeBech32Simple(sv(match).substr(6)));
                     appendLink(std::string("/u/") + u->npubId, std::string("@") + u->username);
                     didTransform = true;
-                } catch(std::exception &e) {
-                    //LW << "tag parse error: " << e.what();
-                }
+                } catch(...) {}
+
+                if (!didTransform) output += sv(match);
+            } else if (match.starts_with("nostr:nprofile")) {
+                bool didTransform = false;
+
+                try {
+                    auto pubkey = decodeBech32GetSpecial(sv(match).substr(6));
+                    const auto *u = userCache.getUser(txn, decomp, pubkey);
+                    appendLink(std::string("/u/") + u->npubId, std::string("@") + u->username);
+                    didTransform = true;
+                } catch(...) {}
 
                 if (!didTransform) output += sv(match);
             } else if (match.starts_with("#[")) {

src/apps/web/bech32.cpp

@@ -37,6 +37,8 @@ namespace bech32
 namespace
 {
 
+const size_t BECH32_MAX_SIZE = 5000;
+
 typedef std::vector<uint8_t> data;
 
 /** The Bech32 character set for encoding. */
@@ -204,7 +206,7 @@ DecodeResult decode(const std::string& str) {
     }
     if (lower && upper) return {};
     size_t pos = str.rfind('1');
-    if (str.size() > 90 || pos == str.npos || pos == 0 || pos + 7 > str.size()) {
+    if (str.size() > BECH32_MAX_SIZE || pos == str.npos || pos == 0 || pos + 7 > str.size()) {
         return {};
     }
     data values(str.size() - 1 - pos);