1crypt_sha256(5) Standards, Environments, and Macros crypt_sha256(5)
2
3
4
6 crypt_sha256 - password hashing module using SHA-256 message hash algo‐
7 rithm
8
10 /usr/lib/security/$ISA/crypt_sha256.so
11
12
14 The crypt_sha256 module is a one-way password hashing module for use
15 with crypt(3C) that uses the SHA-256 message hash algorithm. The algo‐
16 rithm identifier for crypt.conf(4) and policy.conf(4) is 5.
17
18
19 This module is designed to make it difficult to crack passwords that
20 use brute force attacks based on high speed SHA-256 implementations
21 that use code inlining, unrolled loops, and table lookup.
22
23
24 The maximum password length for crypt_sha256 is 255 characters.
25
26
27 The following options can be passed to the module by means of
28 crypt.conf(4):
29
30 rounds=<positive_number>
31
32 Specifies the number of rounds of SHA-256 to use in generation of
33 the salt; the default number of rounds is 5000. Negative values
34 have no effect and are ignored. The minimum number of rounds cannot
35 be below 1000.
36
37 The number of additional rounds is stored in the salt string
38 returned by crypt_gensalt(3C). For example:
39
40 $5,rounds=6000$nlxmTTpz$
41
42 When crypt_gensalt(3C) is being used to generate a new salt, if the
43 number of additional rounds configured in crypt.conf(4) is greater
44 than that in the old salt, the value from crypt.conf(4) is used
45 instead. This allows for migration to stronger (but more time-con‐
46 suming) salts on password change.
47
48
50 See attributes(5) for descriptions of the following attributes:
51
52
53
54
55 ┌─────────────────────────────┬─────────────────────────────┐
56 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
57 ├─────────────────────────────┼─────────────────────────────┤
58 │Interface Stability │Committed │
59 ├─────────────────────────────┼─────────────────────────────┤
60 │MT-Level │Safe │
61 └─────────────────────────────┴─────────────────────────────┘
62
64 passwd(1), crypt(3C), crypt_genhash_impl(3C), crypt_gensalt(3C),
65 crypt_gensalt_impl(3C), getpassphrase(3C), crypt.conf(4), passwd(4),
66 policy.conf(4), attributes(5)
67
68
69
70SunOS 5.11 8 May 2008 crypt_sha256(5)