gistfile1.txt

% ruby -rbcrypt -e '(1..100).each { |len| abort "max len is #{len}" if BCrypt::Password.create("a" * len) == "a" * (len+1) }'
max len is 72
zsh: exit 1     ruby -rbcrypt -e
ruby -rbcrypt -e   9.12s user 0.06s system 99% cpu 9.192 total

% ruby -rbcrypt -rpp -e 'pp (1..100).map { |len| goodpass = "a" * len; badpass = "a" * (len+1); pass = BCrypt::Password.create(goodpass); [len, pass == goodpass, pass == badpass] }'
[[1, true, false],
 [2, true, false],
 [3, true, false],
 [4, true, false],
 [5, true, false],
 [6, true, false],
 [7, true, false],
 [8, true, false],
 [9, true, false],
 [10, true, false],
 [11, true, false],
 [12, true, false],
 [13, true, false],
 [14, true, false],
 [15, true, false],
 [16, true, false],
 [17, true, false],
 [18, true, false],
 [19, true, false],
 [20, true, false],
 [21, true, false],
 [22, true, false],
 [23, true, false],
 [24, true, false],
 [25, true, false],
 [26, true, false],
 [27, true, false],
 [28, true, false],
 [29, true, false],
 [30, true, false],
 [31, true, false],
 [32, true, false],
 [33, true, false],
 [34, true, false],
 [35, true, false],
 [36, true, false],
 [37, true, false],
 [38, true, false],
 [39, true, false],
 [40, true, false],
 [41, true, false],
 [42, true, false],
 [43, true, false],
 [44, true, false],
 [45, true, false],
 [46, true, false],
 [47, true, false],
 [48, true, false],
 [49, true, false],
 [50, true, false],
 [51, true, false],
 [52, true, false],
 [53, true, false],
 [54, true, false],
 [55, true, false],
 [56, true, false],
 [57, true, false],
 [58, true, false],
 [59, true, false],
 [60, true, false],
 [61, true, false],
 [62, true, false],
 [63, true, false],
 [64, true, false],
 [65, true, false],
 [66, true, false],
 [67, true, false],
 [68, true, false],
 [69, true, false],
 [70, true, false],
 [71, true, false],
 [72, true, true],
 [73, true, true],
 [74, true, true],
 [75, true, true],
 [76, true, true],
 [77, true, true],
 [78, true, true],
 [79, true, true],
 [80, true, true],
 [81, true, true],
 [82, true, true],
 [83, true, true],
 [84, true, true],
 [85, true, true],
 [86, true, true],
 [87, true, true],
 [88, true, true],
 [89, true, true],
 [90, true, true],
 [91, true, true],
 [92, true, true],
 [93, true, true],
 [94, true, true],
 [95, true, true],
 [96, true, true],
 [97, true, true],
 [98, true, true],
 [99, true, true],
 [100, true, true]]
ruby -rbcrypt -rpp -e   18.42s user 0.06s system 99% cpu 18.495 total