Fix buggy case in all SHA modules + update changelog

modules/sha1/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Several performance improvements
 - Add `--!native` directive to module to support native codegen in Roblox
+- Fixed incorrect hashing result when input had a length of `55 + 64 * n` where `n` was any integer
 
 ## Version 1.0.2
 

modules/sha1/init.luau

@@ -100,11 +100,15 @@ local function sha1(message: string): (string, { number })
 		processBlocks(digest, message, 1, messageLen - leftover)
 	end
 
-	-- TODO find a way to do this more eloquently
+	-- Raise `leftover` to next multiple of 64 so that we can calculate
+	-- how much padding we need without a branch or loop.
+	-- The number here is just masking off the last 6 bits.
+	local nextMultipleOf64 = bit32.band(leftover + 32, 0xffffffc0)
+
 	local finalMessage = {
 		if leftover ~= 0 then string.sub(message, -leftover) else "",
 		"\x80",
-		string.rep("\0", 64 - (messageLen + 9) % 64),
+		string.rep("\0", (nextMultipleOf64 - leftover - 9) % 64),
 		string.pack(">L", messageLen * 8),
 	}
 	local finalBlock = table.concat(finalMessage)

modules/sha224/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Several performance improvements
 - Add `--!native` directive to module to support native codegen in Roblox
+- Fixed incorrect hashing result when input had a length of `55 + 64 * n` where `n` was any integer
 
 ## Version 1.0.0
 

modules/sha224/init.luau

@@ -119,10 +119,15 @@ local function sha224(message: string): (string, { number })
 		processBlocks(digest, message, 1, messageLen - leftover)
 	end
 
+	-- Raise `leftover` to next multiple of 64 so that we can calculate
+	-- how much padding we need without a branch or loop.
+	-- The number here is just masking off the last 6 bits.
+	local nextMultipleOf64 = bit32.band(leftover + 32, 0xffffffc0)
+
 	local finalMessage = {
 		if leftover ~= 0 then string.sub(message, -leftover) else "",
 		"\x80",
-		string.rep("\0", 64 - (messageLen + 9) % 64),
+		string.rep("\0", (nextMultipleOf64 - leftover - 9) % 64),
 		string.pack(">L", messageLen * 8),
 	}
 	local finalBlock = table.concat(finalMessage)

modules/sha256/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Several performance improvements
 - Add `--!native` directive to module to support native codegen in Roblox
+- Fixed incorrect hashing result when input had a length where `length % 55` was `0`
 
 ## Version 1.0.0
 

modules/sha256/init.luau

@@ -119,10 +119,15 @@ local function sha256(message: string): (string, { number })
 		processBlocks(digest, message, 1, messageLen - leftover)
 	end
 
+	-- Raise `leftover` to next multiple of 64 so that we can calculate
+	-- how much padding we need without a branch or loop.
+	-- The number here is just masking off the last 6 bits.
+	local nextMultipleOf64 = bit32.band(leftover + 32, 0xffff_ffc0)
+
 	local finalMessage = {
 		if leftover ~= 0 then string.sub(message, -leftover) else "",
 		"\x80",
-		string.rep("\0", 64 - (messageLen + 9) % 64),
+		string.rep("\0", (nextMultipleOf64 - leftover - 9) % 64),
 		string.pack(">L", messageLen * 8),
 	}
 	local finalBlock = table.concat(finalMessage)

modules/sha384/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Several performance improvements
 - Add `--!native` directive to module to support native codegen in Roblox
+- Fixed incorrect hashing result when input had a length of `111 + 128 * n` where `n` was any integer
 
 ## Version 1.0.0
 

modules/sha384/init.luau

@@ -292,10 +292,16 @@ local function sha384(message: string): string
 	if messageLen >= 128 then
 		processBlocks(digest_front, digest_back, message, 1, messageLen - leftover)
 	end
+
+	-- Raise `leftover` to next multiple of 128 so that we can calculate
+	-- how much padding we need without a branch or loop.
+	-- The number here is just masking off the last 6 bits.
+	local nextMultipleOf128 = bit32.band(leftover + 64, 0xfffff000)
+
 	local finalMessage = {
 		if leftover ~= 0 then string.sub(message, -leftover) else "",
 		"\x80",
-		string.rep("\0", 128 - (messageLen + 17) % 128),
+		string.rep("\0", (nextMultipleOf128 - leftover - 17) % 128),
 		string.pack(">L", messageLen * 8 / 2 ^ 32),
 		string.pack(">L", bit32.bor(messageLen * 8)),
 	}

modules/sha512/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Several performance improvements
 - Add `--!native` directive to module to support native codegen in Roblox
+- Fixed incorrect hashing result when input had a length of `111 + 128 * n` where `n` was any integer
 
 ## Version 1.0.0
 

modules/sha512/init.luau

@@ -292,10 +292,16 @@ local function sha512(message: string): string
 	if messageLen >= 128 then
 		processBlocks(digest_front, digest_back, message, 1, messageLen - leftover)
 	end
+
+	-- Raise `leftover` to next multiple of 128 so that we can calculate
+	-- how much padding we need without a branch or loop.
+	-- The number here is just masking off the last 6 bits.
+	local nextMultipleOf128 = bit32.band(leftover + 64, 0xfffff000)
+
 	local finalMessage = {
 		if leftover ~= 0 then string.sub(message, -leftover) else "",
 		"\x80",
-		string.rep("\0", 128 - (messageLen + 17) % 128),
+		string.rep("\0", (nextMultipleOf128 - leftover - 17) % 128),
 		string.pack(">L", messageLen * 8 / 2 ^ 32),
 		string.pack(">L", messageLen * 8 % 2 ^ 32),
 	}