Clarify the use of a 64-bits ChaCha counter

yorickpeterse · yorickpeterse · commit af8f6c7c178b · 2025-02-23T22:36:32.000+01:00
diff --git a/std/src/std/crypto/chacha.inko b/std/src/std/crypto/chacha.inko
@@ -174,9 +174,9 @@ type inline Matrix {
 #
 # # Limitations
 #
-# As our implementation is based on RFC 8439, the total message size is limited
-# to 256 GiB. When reaching this limit the cipher panics, as the alternative is
-# a silent overflow that could lead to weaker/broken encryption.
+# The implementation deviates from the RFC by using a 64-bits counter instead of
+# a 32-bits counter. If the counter overflows, the `ChaCha.encrypt` and
+# `ChaCha.decrypt` methods will panic.
 #
 # # Examples
 #

Original file line number	Diff line number	Diff line change
`@@ -174,9 +174,9 @@ type inline Matrix {`
`174`	`174`	`#`
`175`	`175`	`# # Limitations`
`176`	`176`	`#`
`177`		`-# As our implementation is based on RFC 8439, the total message size is limited`
`178`		`-# to 256 GiB. When reaching this limit the cipher panics, as the alternative is`
`179`		`-# a silent overflow that could lead to weaker/broken encryption.`
	`177`	`+# The implementation deviates from the RFC by using a 64-bits counter instead of`
	`178`	+# a 32-bits counter. If the counter overflows, the `ChaCha.encrypt` and
	`179`	+# `ChaCha.decrypt` methods will panic.
`180`	`180`	`#`
`181`	`181`	`# # Examples`
`182`	`182`	`#`