Inital embedded content parser

This adds some initial code for nostrdb content parsing.

We still need to write tests for encoding and decoding, so this is
likely not working yet.

Makefile

@@ -2,7 +2,7 @@ CFLAGS = -Wall -Wno-misleading-indentation -Wno-unused-function -Werror -O2 -g -
 HEADERS = deps/lmdb/lmdb.h deps/secp256k1/include/secp256k1.h src/sha256.h src/nostrdb.h src/cursor.h src/hex.h src/jsmn.h src/config.h src/sha256.h src/random.h src/memchr.h src/cpu.h $(C_BINDINGS) 
 FLATCC_SRCS=deps/flatcc/src/runtime/json_parser.c deps/flatcc/src/runtime/verifier.c deps/flatcc/src/runtime/builder.c deps/flatcc/src/runtime/emitter.c deps/flatcc/src/runtime/refmap.c
 BOLT11_SRCS = src/bolt11/bolt11.c src/bolt11/bech32.c src/bolt11/tal.c src/bolt11/talstr.c src/bolt11/take.c src/bolt11/list.c src/bolt11/utf8.c src/bolt11/amount.c src/bolt11/hash_u5.c
-SRCS = src/nostrdb.c src/sha256.c src/invoice.c $(BOLT11_SRCS) $(FLATCC_SRCS)
+SRCS = src/nostrdb.c src/sha256.c src/invoice.c src/nostr_bech32.c src/content_parser.c $(BOLT11_SRCS) $(FLATCC_SRCS)
 LDS = $(OBJS) $(ARS) 
 OBJS = $(SRCS:.c=.o)
 DEPS = $(OBJS) $(HEADERS) $(ARS)
@@ -41,7 +41,7 @@ check: test
 	rm -rf testdata/db/*.mdb
 
 clean:
-	rm -rf test bench bench-ingest bench-ingest-many
+	rm -rf test bench bench-ingest bench-ingest-many $(OBJS)
 
 distclean: clean
 	rm -rf deps

src/bolt11/bech32.c

@@ -91,7 +91,7 @@ int bech32_encode(char *output, const char *hrp, const uint8_t *data, size_t dat
     return 1;
 }
 
-bech32_encoding bech32_decode_len(char* hrp, uint8_t *data, size_t *data_len, const char *input, size_t input_len) {
+bech32_encoding bech32_decode_len(char* hrp, uint8_t *data, size_t *data_len, const char *input, size_t input_len, int max_hrp_len) {
     uint32_t chk = 1;
     size_t i;
     size_t hrp_len;
@@ -104,6 +104,8 @@ bech32_encoding bech32_decode_len(char* hrp, uint8_t *data, size_t *data_len, co
         ++(*data_len);
     }
     hrp_len = input_len - (1 + *data_len);
+    if (hrp_len > max_hrp_len)
+	    return BECH32_ENCODING_NONE;
     if (1 + *data_len >= input_len || *data_len < 6) {
         return BECH32_ENCODING_NONE;
     }
@@ -158,13 +160,14 @@ bech32_encoding bech32_decode(char* hrp, uint8_t *data, size_t *data_len, const
     if (len > max_input_len) {
         return BECH32_ENCODING_NONE;
     }
-    return bech32_decode_len(hrp, data, data_len, input, len);
+    return bech32_decode_len(hrp, data, data_len, input, len, 8);
 }
 
 int bech32_convert_bits(uint8_t* out, size_t* outlen, int outbits, const uint8_t* in, size_t inlen, int inbits, int pad) {
     uint32_t val = 0;
     int bits = 0;
     uint32_t maxv = (((uint32_t)1) << outbits) - 1;
+    *outlen = 0;
     while (inlen--) {
         val = (val << inbits) | *(in++);
         bits += inbits;

src/bolt11/bech32.h

@@ -123,7 +123,8 @@ bech32_encoding bech32_decode_len(
     uint8_t *data,
     size_t *data_len,
     const char *input,
-    size_t input_len
+    size_t input_len,
+    int max_prefix_len
 );
 
 /* Helper from bech32: translates inbits-bit bytes to outbits-bit bytes.

src/bolt11/bolt11.h

@@ -3,6 +3,7 @@
 
 #include "short_types.h"
 #include "hash_u5.h"
+#include "amount.h"
 #include "list.h"
 #include "amount.h"
 #include "node_id.h"