[cryptography/dkg] validate players length before cast in deal()#3272
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0xAysh wants to merge 1 commit intocommonwarexyz:mainfrom
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[cryptography/dkg] validate players length before cast in deal()#32720xAysh wants to merge 1 commit intocommonwarexyz:mainfrom
0xAysh wants to merge 1 commit intocommonwarexyz:mainfrom
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players.len() was cast to u32 without an upper bound check, allowing silent truncation on 64-bit systems. Mirror the existing validation pattern from Info::new() using the 1..u32::MAX range guard. Closes commonwarexyz#3062
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Fixes #3062
The issue flagged that
deal()was castingplayers.len() as u32without validating the upper bound. Values aboveu32::MAXsilently truncate — a set ofu32::MAX + 2players would cast to1, causingdeal()to compute a DKG withn = 1instead of the real participant count, producing cryptographically invalid shares with no error surfaced to the caller.The issue decription alos mentioned that
Info::new()already solves this exactly using aparticipant_rangeguard that covers both the lower bound (empty) and upper bound (overflow) in one check, reusing the existingError::NumPlayersvariant.deal()is a convenience helper that bypasses the full DKG path and had simply missed copying this guard.The fix mirrors
Info::new()directly so the validation pattern is consistent across the file.Closes #3062