From b8e9f6f48210a7f68fd602e361b56c6235fd4425 Mon Sep 17 00:00:00 2001
From: 0xFEEDC0DE64 <daniel@brunner.ninja>
Date: Thu, 30 Jun 2022 06:56:08 +0200
Subject: [PATCH] Add toBase64String()

---
 src/strutils.cpp | 29 +++++++++++++++++++++++++++++
 src/strutils.h   |  6 ++++++
 2 files changed, 35 insertions(+)

diff --git a/src/strutils.cpp b/src/strutils.cpp
index c900145..3c1656d 100644
--- a/src/strutils.cpp
+++ b/src/strutils.cpp
@@ -78,6 +78,35 @@ tl::expected<std::basic_string<unsigned char>, std::string> fromHexString(std::s
     return result;
 }
 
+std::string toBase64String(std::basic_string_view<unsigned char> buf)
+{
+    constexpr std::string_view base64_chars{"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"};
+
+    std::string out;
+
+    int val = 0;
+    int valb = -6;
+    for (unsigned char c : buf)
+    {
+        val = (val << 8) + c;
+        valb += 8;
+
+        while (valb >= 0)
+        {
+            out.push_back(base64_chars[(val>>valb)&0x3F]);
+            valb -= 6;
+        }
+    }
+
+    if (valb>-6)
+        out.push_back(base64_chars[((val << 8) >> (valb + 8)) & 0x3F]);
+
+    while (out.size() % 4)
+        out.push_back('=');
+
+    return out;
+}
+
 bool stringEqualsIgnoreCase(std::string_view a, std::string_view b)
 {
     if (a.size() != b.size())
diff --git a/src/strutils.h b/src/strutils.h
index 6ef8eb7..068c5bc 100644
--- a/src/strutils.h
+++ b/src/strutils.h
@@ -44,6 +44,12 @@ inline std::string toHexString(std::string_view str)
 
 tl::expected<std::basic_string<unsigned char>, std::string> fromHexString(std::string_view hex);
 
+std::string toBase64String(std::basic_string_view<unsigned char> buf);
+inline std::string toBase64String(std::string_view str)
+{
+    return toBase64String(std::basic_string_view<unsigned char>{reinterpret_cast<const unsigned char *>(str.data()), str.size()});
+}
+
 bool stringEqualsIgnoreCase(std::string_view a, std::string_view b);
 
 //void stringReplaceAll(char search, char replace, std::string &subject);