Use constant-time comparison for MAC and hash verification#27
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kodareef5 wants to merge 2 commits intontp-project:stablefrom
Open
Use constant-time comparison for MAC and hash verification#27kodareef5 wants to merge 2 commits intontp-project:stablefrom
kodareef5 wants to merge 2 commits intontp-project:stablefrom
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Four sprintf calls write formatted GPS receiver data into a 1024-byte logbuf without bounds checking. The C1 format string at line 1677 has 17 format specifiers including floating-point values that can produce long output. Replace with snprintf bounded by sizeof(logbuf).
Two locations use memcmp() for cryptographic verification: - sntp/crypto.c:181: NTP packet MAC verification. The developer comment at line 177 acknowledges "isc_tsmemcmp will be better" but the fix was never applied. - ntpd/ntp_leapsec.c:1144: SHA1 digest comparison for leap second file integrity in the long-running ntpd daemon. Replace both with constant-time XOR accumulation loops.
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Two locations use
memcmp()for cryptographic verification:sntp/crypto.c:181— NTP packet MAC verification. The developer comment at line 177 acknowledgesisc_tsmemcmp will be better when its easy to link withbut the fix was never applied.ntpd/ntp_leapsec.c:1144— SHA1 digest comparison for leap second file integrity verification in the long-running ntpd daemon.Replace both with constant-time XOR accumulation loops that examine all bytes regardless of match position.