c: move c files into nostrdb in prep for switchover

nostrdb/hex.c

@@ -0,0 +1,57 @@
+/* CC0 license (public domain) - see LICENSE file for details */
+#include "hex.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static bool char_to_hex(unsigned char *val, char c)
+{
+    if (c >= '0' && c <= '9') {
+        *val = c - '0';
+        return true;
+    }
+     if (c >= 'a' && c <= 'f') {
+        *val = c - 'a' + 10;
+        return true;
+    }
+     if (c >= 'A' && c <= 'F') {
+        *val = c - 'A' + 10;
+        return true;
+    }
+    return false;
+}
+
+bool hex_decode(const char *str, size_t slen, void *buf, size_t bufsize)
+{
+    unsigned char v1, v2;
+    unsigned char *p = buf;
+
+    while (slen > 1) {
+        if (!char_to_hex(&v1, str[0]) || !char_to_hex(&v2, str[1]))
+            return false;
+        if (!bufsize)
+            return false;
+        *(p++) = (v1 << 4) | v2;
+        str += 2;
+        slen -= 2;
+        bufsize--;
+    }
+    return slen == 0 && bufsize == 0;
+}
+
+bool hex_encode(const void *buf, size_t bufsize, char *dest, size_t destsize)
+{
+    size_t i;
+
+    if (destsize < hex_str_size(bufsize))
+        return false;
+
+    for (i = 0; i < bufsize; i++) {
+        unsigned int c = ((const unsigned char *)buf)[i];
+        *(dest++) = hexchar(c >> 4);
+        *(dest++) = hexchar(c & 0xF);
+    }
+    *dest = '\0';
+
+    return true;
+}