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1 | #include "includes.h" | |
2 | ||
3 | #ifdef SKEY | |
4 | RCSID("$Id$"); | |
5 | ||
6 | #include "ssh.h" | |
7 | #include "packet.h" | |
8 | ||
9 | #ifdef HAVE_OPENSSL | |
10 | #include <openssl/sha1.h> | |
11 | #endif | |
12 | #ifdef HAVE_SSL | |
13 | #include <ssl/sha1.h> | |
14 | #endif | |
15 | ||
16 | /* from %OpenBSD: skeylogin.c,v 1.32 1999/08/16 14:46:56 millert Exp % */ | |
17 | ||
18 | /* | |
19 | * try skey authentication, | |
20 | * return 1 on success, 0 on failure, -1 if skey is not available | |
21 | */ | |
22 | ||
23 | int | |
24 | auth_skey_password(struct passwd * pw, const char *password) | |
25 | { | |
26 | if (strncasecmp(password, "s/key", 5) == 0) { | |
27 | char *skeyinfo = skey_keyinfo(pw->pw_name); | |
28 | if (skeyinfo == NULL) { | |
29 | debug("generating fake skeyinfo for %.100s.", | |
30 | pw->pw_name); | |
31 | skeyinfo = skey_fake_keyinfo(pw->pw_name); | |
32 | } | |
33 | if (skeyinfo != NULL) | |
34 | packet_send_debug(skeyinfo); | |
35 | /* Try again. */ | |
36 | return 0; | |
37 | } else if (skey_haskey(pw->pw_name) == 0 && | |
38 | skey_passcheck(pw->pw_name, (char *) password) != -1) { | |
39 | /* Authentication succeeded. */ | |
40 | return 1; | |
41 | } | |
42 | /* Fall back to ordinary passwd authentication. */ | |
43 | return -1; | |
44 | } | |
45 | ||
46 | /* from %OpenBSD: skeylogin.c,v 1.32 1999/08/16 14:46:56 millert Exp % */ | |
47 | ||
48 | #define ROUND(x) (((x)[0] << 24) + (((x)[1]) << 16) + (((x)[2]) << 8) + \ | |
49 | ((x)[3])) | |
50 | ||
51 | /* | |
52 | * hash_collapse() | |
53 | */ | |
54 | static u_int32_t | |
55 | hash_collapse(s) | |
56 | u_char *s; | |
57 | { | |
58 | int len, target; | |
59 | u_int32_t i; | |
60 | ||
61 | if ((strlen(s) % sizeof(u_int32_t)) == 0) | |
62 | target = strlen(s); /* Multiple of 4 */ | |
63 | else | |
64 | target = strlen(s) - (strlen(s) % sizeof(u_int32_t)); | |
65 | ||
66 | for (i = 0, len = 0; len < target; len += 4) | |
67 | i ^= ROUND(s + len); | |
68 | ||
69 | return i; | |
70 | } | |
71 | ||
72 | char * | |
73 | skey_fake_keyinfo(char *username) | |
74 | { | |
75 | int i; | |
76 | u_int ptr; | |
77 | u_char hseed[SKEY_MAX_SEED_LEN], flg = 1, *up; | |
78 | char pbuf[SKEY_MAX_PW_LEN+1]; | |
79 | static char skeyprompt[SKEY_MAX_CHALLENGE+1]; | |
80 | char *secret = NULL; | |
81 | size_t secretlen = 0; | |
82 | SHA1_CTX ctx; | |
83 | char *p, *u; | |
84 | ||
85 | /* | |
86 | * Base first 4 chars of seed on hostname. | |
87 | * Add some filler for short hostnames if necessary. | |
88 | */ | |
89 | if (gethostname(pbuf, sizeof(pbuf)) == -1) | |
90 | *(p = pbuf) = '.'; | |
91 | else | |
92 | for (p = pbuf; *p && isalnum(*p); p++) | |
93 | if (isalpha(*p) && isupper(*p)) | |
94 | *p = tolower(*p); | |
95 | if (*p && pbuf - p < 4) | |
96 | (void)strncpy(p, "asjd", 4 - (pbuf - p)); | |
97 | pbuf[4] = '\0'; | |
98 | ||
99 | /* Hash the username if possible */ | |
100 | if ((up = SHA1Data(username, strlen(username), NULL)) != NULL) { | |
101 | struct stat sb; | |
102 | time_t t; | |
103 | int fd; | |
104 | ||
105 | /* Collapse the hash */ | |
106 | ptr = hash_collapse(up); | |
107 | memset(up, 0, strlen(up)); | |
108 | ||
109 | /* See if the random file's there, else use ctime */ | |
110 | if ((fd = open(_SKEY_RAND_FILE_PATH_, O_RDONLY)) != -1 | |
111 | && fstat(fd, &sb) == 0 && | |
112 | sb.st_size > (off_t)SKEY_MAX_SEED_LEN && | |
113 | lseek(fd, ptr % (sb.st_size - SKEY_MAX_SEED_LEN), | |
114 | SEEK_SET) != -1 && read(fd, hseed, | |
115 | SKEY_MAX_SEED_LEN) == SKEY_MAX_SEED_LEN) { | |
116 | close(fd); | |
117 | fd = -1; | |
118 | secret = hseed; | |
119 | secretlen = SKEY_MAX_SEED_LEN; | |
120 | flg = 0; | |
121 | } else if (!stat(_PATH_MEM, &sb) || !stat("/", &sb)) { | |
122 | t = sb.st_ctime; | |
123 | secret = ctime(&t); | |
124 | secretlen = strlen(secret); | |
125 | flg = 0; | |
126 | } | |
127 | if (fd != -1) | |
128 | close(fd); | |
129 | } | |
130 | ||
131 | /* Put that in your pipe and smoke it */ | |
132 | if (flg == 0) { | |
133 | /* Hash secret value with username */ | |
134 | SHA1Init(&ctx); | |
135 | SHA1Update(&ctx, secret, secretlen); | |
136 | SHA1Update(&ctx, username, strlen(username)); | |
137 | SHA1End(&ctx, up); | |
138 | ||
139 | /* Zero out */ | |
140 | memset(secret, 0, secretlen); | |
141 | ||
142 | /* Now hash the hash */ | |
143 | SHA1Init(&ctx); | |
144 | SHA1Update(&ctx, up, strlen(up)); | |
145 | SHA1End(&ctx, up); | |
146 | ||
147 | ptr = hash_collapse(up + 4); | |
148 | ||
149 | for (i = 4; i < 9; i++) { | |
150 | pbuf[i] = (ptr % 10) + '0'; | |
151 | ptr /= 10; | |
152 | } | |
153 | pbuf[i] = '\0'; | |
154 | ||
155 | /* Sequence number */ | |
156 | ptr = ((up[2] + up[3]) % 99) + 1; | |
157 | ||
158 | memset(up, 0, 20); /* SHA1 specific */ | |
159 | free(up); | |
160 | ||
161 | (void)snprintf(skeyprompt, sizeof skeyprompt, | |
162 | "otp-%.*s %d %.*s", | |
163 | SKEY_MAX_HASHNAME_LEN, | |
164 | skey_get_algorithm(), | |
165 | ptr, SKEY_MAX_SEED_LEN, | |
166 | pbuf); | |
167 | } else { | |
168 | /* Base last 8 chars of seed on username */ | |
169 | u = username; | |
170 | i = 8; | |
171 | p = &pbuf[4]; | |
172 | do { | |
173 | if (*u == 0) { | |
174 | /* Pad remainder with zeros */ | |
175 | while (--i >= 0) | |
176 | *p++ = '0'; | |
177 | break; | |
178 | } | |
179 | ||
180 | *p++ = (*u++ % 10) + '0'; | |
181 | } while (--i != 0); | |
182 | pbuf[12] = '\0'; | |
183 | ||
184 | (void)snprintf(skeyprompt, sizeof skeyprompt, | |
185 | "otp-%.*s %d %.*s", | |
186 | SKEY_MAX_HASHNAME_LEN, | |
187 | skey_get_algorithm(), | |
188 | 99, SKEY_MAX_SEED_LEN, pbuf); | |
189 | } | |
190 | return skeyprompt; | |
191 | } | |
192 | ||
193 | #endif /* SKEY */ |