projects / thirdparty / systemd.git / blame
| Commit | Line | Data |
|---|---|---|
| 42f3b2f9 LP |
1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
| 2 | ||
| 3 | #include <errno.h> | |
| 4 | #include <stdlib.h> | |
| 5 | ||
| 6 | #include "alloc-util.h" | |
| 7 | #include "libcrypt-util.h" | |
| 8 | #include "log.h" | |
| 9 | #include "macro.h" | |
| 10 | #include "missing_stdlib.h" | |
| 11 | #include "random-util.h" | |
| 12 | #include "string-util.h" | |
| 13 | #include "strv.h" | |
| 14 | ||
| 15 | int make_salt(char **ret) { | |
| 16 | ||
| 17 | #ifdef XCRYPT_VERSION_MAJOR | |
| 18 | const char *e; | |
| 19 | char *salt; | |
| 20 | ||
| 21 | /* If we have libxcrypt we default to the "preferred method" (i.e. usually yescrypt), and generate it | |
| 22 | * with crypt_gensalt_ra(). */ | |
| 23 | ||
| 24 | e = secure_getenv("SYSTEMD_CRYPT_PREFIX"); | |
| 25 | if (!e) | |
| 26 | e = crypt_preferred_method(); | |
| 27 | ||
| 28 | log_debug("Generating salt for hash prefix: %s", e); | |
| 29 | ||
| 30 | salt = crypt_gensalt_ra(e, 0, NULL, 0); | |
| 31 | if (!salt) | |
| 32 | return -errno; | |
| 33 | ||
| 34 | *ret = salt; | |
| 35 | return 0; | |
| 36 | #else | |
| 37 | /* If libxcrypt is not used, we use SHA512 and generate the salt on our own since crypt_gensalt_ra() | |
| 38 | * is not available. */ | |
| 39 | ||
| 40 | static const char table[] = | |
| 41 | "abcdefghijklmnopqrstuvwxyz" | |
| 42 | "ABCDEFGHIJKLMNOPQRSTUVWXYZ" | |
| 43 | "0123456789" | |
| 44 | "./"; | |
| 45 | ||
| 46 | uint8_t raw[16]; | |
| 47 | char *salt, *j; | |
| 48 | size_t i; | |
| 49 | int r; | |
| 50 | ||
| 51 | /* This is a bit like crypt_gensalt_ra(), but doesn't require libcrypt, and doesn't do anything but | |
| 52 | * SHA512, i.e. is legacy-free and minimizes our deps. */ | |
| 53 | ||
| 54 | assert_cc(sizeof(table) == 64U + 1U); | |
| 55 | ||
| 56 | /* Insist on the best randomness by setting RANDOM_BLOCK, this is about keeping passwords secret after all. */ | |
| 57 | r = genuine_random_bytes(raw, sizeof(raw), RANDOM_BLOCK); | |
| 58 | if (r < 0) | |
| 59 | return r; | |
| 60 | ||
| 61 | salt = new(char, 3+sizeof(raw)+1+1); | |
| 62 | if (!salt) | |
| 63 | return -ENOMEM; | |
| 64 | ||
| 65 | /* We only bother with SHA512 hashed passwords, the rest is legacy, and we don't do legacy. */ | |
| 66 | j = stpcpy(salt, "$6$"); | |
| 67 | for (i = 0; i < sizeof(raw); i++) | |
| 68 | j[i] = table[raw[i] & 63]; | |
| 69 | j[i++] = '$'; | |
| 70 | j[i] = 0; | |
| 71 | ||
| 72 | *ret = salt; | |
| 73 | return 0; | |
| 74 | #endif | |
| 75 | } | |
| 64aa2622 LP |
76 | |
| 77 | bool hashed_password_valid(const char *s) { | |
| 78 | ||
| 79 | /* Returns true if the specified string is a 'valid' hashed UNIX password, i.e. if starts with '$' or | |
| 80 | * with '!$' (the latter being a valid, yet locked password). */ | |
| 81 | ||
| 82 | if (isempty(s)) | |
| 83 | return false; | |
| 84 | ||
| 85 | return STARTSWITH_SET(s, "$", "!$"); | |
| 86 | } |