1 files changed, 32 insertions, 2 deletions
diff --git a/src/utilstrencodings.h b/src/utilstrencodings.h
index 707fdaad16..af33f0e5f8 100644
--- a/src/utilstrencodings.h
+++ b/src/utilstrencodings.h
@@ -38,12 +38,18 @@ std::string SanitizeString(const std::string& str, int rule = SAFE_CHARS_DEFAULT
 std::vector<unsigned char> ParseHex(const char* psz);
 std::vector<unsigned char> ParseHex(const std::string& str);
 signed char HexDigit(char c);
+/* Returns true if each character in str is a hex character, and has an even
+ * number of hex digits.*/
 bool IsHex(const std::string& str);
-std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid = NULL);
+/**
+* Return true if the string is a hex number, optionally prefixed with "0x"
+*/
+bool IsHexNumber(const std::string& str);
+std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid = nullptr);
 std::string DecodeBase64(const std::string& str);
 std::string EncodeBase64(const unsigned char* pch, size_t len);
 std::string EncodeBase64(const std::string& str);
-std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid = NULL);
+std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid = nullptr);
 std::string DecodeBase32(const std::string& str);
 std::string EncodeBase32(const unsigned char* pch, size_t len);
 std::string EncodeBase32(const std::string& str);
@@ -143,4 +149,28 @@ bool TimingResistantEqual(const T& a, const T& b)
  */
 bool ParseFixedPoint(const std::string &val, int decimals, int64_t *amount_out);
 
+/** Convert from one power-of-2 number base to another. */
+template<int frombits, int tobits, bool pad, typename O, typename I>
+bool ConvertBits(O& out, I it, I end) {
+    size_t acc = 0;
+    size_t bits = 0;
+    constexpr size_t maxv = (1 << tobits) - 1;
+    constexpr size_t max_acc = (1 << (frombits + tobits - 1)) - 1;
+    while (it != end) {
+        acc = ((acc << frombits) | *it) & max_acc;
+        bits += frombits;
+        while (bits >= tobits) {
+            bits -= tobits;
+            out.push_back((acc >> bits) & maxv);
+        }
+        ++it;
+    }
+    if (pad) {
+        if (bits) out.push_back((acc << (tobits - bits)) & maxv);
+    } else if (bits >= frombits || ((acc << (tobits - bits)) & maxv)) {
+        return false;
+    }
+    return true;
+}
+
 #endif // BITCOIN_UTILSTRENCODINGS_H