From 360f899f68a97f4bae5eaf898dc32dcd063cdf1d Mon Sep 17 00:00:00 2001
From: LillyJadeKatrin <lilly.kitty.1988@gmail.com>
Date: Wed, 26 Jun 2024 20:05:54 -0400
Subject: [PATCH] Common/Crypto/SHA1: Add DigestToString() utility function

---
 Source/Core/Common/Crypto/SHA1.cpp | 16 ++++++++++++++++
 Source/Core/Common/Crypto/SHA1.h   |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/Source/Core/Common/Crypto/SHA1.cpp b/Source/Core/Common/Crypto/SHA1.cpp
index f87bbd2c6d..8c4aa646bd 100644
--- a/Source/Core/Common/Crypto/SHA1.cpp
+++ b/Source/Core/Common/Crypto/SHA1.cpp
@@ -385,4 +385,20 @@ Digest CalculateDigest(const u8* msg, size_t len)
   ctx->Update(msg, len);
   return ctx->Finish();
 }
+
+std::string DigestToString(const Digest& digest)
+{
+  static constexpr std::array<char, 16> lookup = {'0', '1', '2', '3', '4', '5', '6', '7',
+                                                  '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
+  std::string hash;
+  hash.reserve(digest.size() * 2);
+  for (size_t i = 0; i < digest.size(); ++i)
+  {
+    const u8 upper = static_cast<u8>((digest[i] >> 4) & 0xf);
+    const u8 lower = static_cast<u8>(digest[i] & 0xf);
+    hash.push_back(lookup[upper]);
+    hash.push_back(lookup[lower]);
+  }
+  return hash;
+}
 }  // namespace Common::SHA1
diff --git a/Source/Core/Common/Crypto/SHA1.h b/Source/Core/Common/Crypto/SHA1.h
index 83c9875a71..b828c28f15 100644
--- a/Source/Core/Common/Crypto/SHA1.h
+++ b/Source/Core/Common/Crypto/SHA1.h
@@ -51,4 +51,6 @@ inline Digest CalculateDigest(const std::array<T, Size>& msg)
   static_assert(std::is_trivially_copyable_v<T>);
   return CalculateDigest(reinterpret_cast<const u8*>(msg.data()), sizeof(msg));
 }
+
+std::string DigestToString(const Digest& digest);
 }  // namespace Common::SHA1