[01044ac] | 1 | #define GNU_SOURCE |
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[085f159] | 2 | #include <credentials/keys/private_key.h> |
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| 3 | |
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| 4 | #include "creddy.h" |
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| 5 | |
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[01044ac] | 6 | #include <termios.h> |
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| 7 | |
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[085f159] | 8 | #define ROLE_SEPARATOR " <- " |
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[ee5afdd] | 9 | #define SHA1_LENGTH 40 |
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[085f159] | 10 | |
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[01044ac] | 11 | /* Callback configuration */ |
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| 12 | struct cb_opts { |
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| 13 | bool use_prompt; /* Print a prompt to stderr */ |
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| 14 | bool use_echo; /* If true, turn off input echo on stdin */ |
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| 15 | unsigned int tries; /* Number of attempts allowed */ |
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| 16 | char prompt[20]; /* The prompt to display if use_echo is true */ |
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| 17 | }; |
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| 18 | |
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| 19 | chunk_t passphrase_callback(void *user, int try) { |
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| 20 | /* Get a password from stdin and return it as a chunk_t. If too many tries |
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| 21 | * have occurred or there is any other problem, return an empty chunk_t, |
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| 22 | * which libstrongswan takes as giving up. The chunk is alloated here |
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| 23 | * (inside getline), and presumably freed by libstrongswan. User points to |
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| 24 | * a cb_opts struct, which affects this routine in the obvious ways. |
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| 25 | */ |
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| 26 | /* Configuration options */ |
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| 27 | struct cb_opts *opts = (struct cb_opts *) user; |
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| 28 | chunk_t rv = chunk_empty; /* Return value, starts empty */ |
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| 29 | |
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| 30 | if (try -1 < opts->tries ) { |
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| 31 | struct termios t; /* Terminal settings */ |
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| 32 | size_t len = 0; /* Length of string from getline */ |
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| 33 | tcflag_t orig = 0; /* Holds the original local flags (echo in here) */ |
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| 34 | |
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| 35 | if (!opts->use_echo) { |
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| 36 | /* Use tc{get,set}attr to turn echo off and restore the intial |
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| 37 | * echo settings */ |
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| 38 | if (!tcgetattr(0, &t)) { |
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| 39 | orig = t.c_lflag; |
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| 40 | |
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| 41 | t.c_lflag &= ~ECHO; |
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| 42 | if ( tcsetattr(0, TCSANOW, &t) ) { |
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| 43 | perror("Cannot turn off echo"); |
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| 44 | return rv; |
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| 45 | } |
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| 46 | } |
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| 47 | else { |
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| 48 | perror("Cannot turn get attributes to off echo"); |
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| 49 | return rv; |
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| 50 | } |
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| 51 | } |
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| 52 | if (opts->use_prompt) printf("%s", opts->prompt); |
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| 53 | |
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| 54 | /* Because rv.ptr starts as NULL, getline allocates memory. The size |
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| 55 | * of the allocation returns in rv.len and the size of the string |
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| 56 | * (including newline and NUL) is in len. */ |
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| 57 | len = getline(&rv.ptr, &rv.len, stdin); |
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| 58 | |
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| 59 | if (!opts->use_echo ) { |
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| 60 | /* Pop echo beck to its original setting. */ |
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| 61 | t.c_lflag = orig; |
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| 62 | |
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| 63 | if ( tcsetattr(0, TCSANOW, &t) ) |
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| 64 | perror("Cannot restore echo setting?"); |
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| 65 | |
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| 66 | if (opts->use_prompt) printf("\n"); |
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| 67 | } |
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| 68 | |
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| 69 | /* Readjust the chunk_t's len field to the size of the string w/o the |
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| 70 | * newline or NUL */ |
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| 71 | if ( len != ~0 ) { |
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| 72 | if (rv.ptr[len-2] == '\n') rv.len = len-2; |
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| 73 | else rv.len = len -1; |
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| 74 | } |
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| 75 | else { |
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| 76 | /* A ~0 len (size_t is unsigned) indicates EOF with an empty line. |
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| 77 | * Deallocate any empty allocation */ |
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| 78 | if (rv.ptr) |
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| 79 | free(rv.ptr); |
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| 80 | |
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| 81 | rv = chunk_empty; |
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| 82 | } |
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| 83 | } |
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| 84 | else fprintf(stderr, "Too many tries (%d)", try-1); |
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| 85 | return rv; |
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| 86 | } |
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| 87 | |
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| 88 | |
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[085f159] | 89 | void attribute_main(options_t *opts) { |
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[ee5afdd] | 90 | char *subject_id = NULL; |
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[01044ac] | 91 | struct cb_opts c_opts = { 1, 0, 3, "Key password:" }; |
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[ee5afdd] | 92 | |
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[085f159] | 93 | if ( |
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| 94 | opts->issuer == NULL || |
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| 95 | opts->key == NULL || |
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| 96 | opts->role == NULL || |
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| 97 | opts->out == NULL |
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| 98 | ) |
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| 99 | usage(opts); |
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| 100 | |
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[ee5afdd] | 101 | // make sure we have exactly one of --subject-cert / --subject-id |
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| 102 | if (opts->subject_cert == NULL && opts->subject_id == NULL) |
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| 103 | usage(opts); |
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| 104 | if (opts->subject_cert && opts->subject_id) { |
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| 105 | printf("Need exactly one of --subject-cert / --subject-id"); |
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| 106 | usage(opts); |
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| 107 | } |
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| 108 | |
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| 109 | // if we have an ID, make sure it's SHA1 and lowercase |
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| 110 | if (opts->subject_id) { |
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| 111 | int i; |
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| 112 | subject_id = opts->subject_id; |
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| 113 | |
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| 114 | // hex chars (also convert to lowercase) |
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| 115 | for (i = 0; subject_id[i]; ++i) { |
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| 116 | subject_id[i] = tolower(subject_id[i]); |
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| 117 | if (!isxdigit(subject_id[i])) { |
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| 118 | printf("Invalid subject ID: must be SHA1\n"); |
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| 119 | usage(opts); |
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| 120 | } |
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| 121 | } |
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| 122 | |
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| 123 | // correct length |
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| 124 | if (i != SHA1_LENGTH) { |
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| 125 | printf("Invalid subject ID: must be SHA1 (too long)\n"); |
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| 126 | usage(opts); |
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| 127 | } |
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| 128 | } |
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| 129 | |
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[085f159] | 130 | if (!clean_name(opts->role)) { |
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| 131 | printf("bad role name\n"); |
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| 132 | usage(opts); |
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| 133 | } |
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| 134 | |
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| 135 | // verify the subject role name if present |
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| 136 | if (opts->subject_role) { |
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| 137 | char *role = opts->subject_role; |
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| 138 | char *start[3]; |
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| 139 | int name_parts = 0, i; |
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| 140 | |
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| 141 | start[name_parts++] = role; |
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| 142 | |
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| 143 | for (i = 0; role[i] != '\0'; ++i) |
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| 144 | if (role[i] == '.') { |
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| 145 | if (name_parts == 3) { |
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| 146 | printf("bad subject role name (too many dots)\n"); |
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| 147 | usage(opts); |
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| 148 | } |
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| 149 | start[name_parts++] = &role[i+1]; |
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| 150 | role[i] = 0; |
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| 151 | } |
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| 152 | |
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| 153 | for (i = 0; i < name_parts; ++i) |
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| 154 | if (!clean_name(start[i])) { |
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| 155 | printf("bad subject role name\n"); |
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| 156 | usage(opts); |
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| 157 | } |
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| 158 | |
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| 159 | for (i = 1; i < name_parts; ++i) |
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| 160 | *(start[i]-1) = '.'; // replace the dot |
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| 161 | } |
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| 162 | |
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| 163 | if (opts->validity < 0) { |
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| 164 | printf("Validity must be >= 1 day\n"); |
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| 165 | usage(opts); |
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| 166 | } |
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| 167 | |
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[01044ac] | 168 | chunk_t pw = chunk_empty; |
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[085f159] | 169 | // load signer key |
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| 170 | private_key_t *key = lib->creds->create(lib->creds, |
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| 171 | CRED_PRIVATE_KEY, KEY_RSA, |
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| 172 | BUILD_FROM_FILE, opts->key, |
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[01044ac] | 173 | /* Ask for password if the key's encrypted */ |
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| 174 | BUILD_PASSPHRASE_CALLBACK, passphrase_callback, &c_opts, |
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[085f159] | 175 | BUILD_END |
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| 176 | ); |
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| 177 | if (key == NULL) |
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| 178 | errx(1, "can't open private key file %s", opts->key); |
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| 179 | |
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| 180 | // get the keyids |
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| 181 | certificate_t *issuer = cert_from_file(opts->issuer); |
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| 182 | char *issuer_id = cert_keyid(issuer); |
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| 183 | |
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[ee5afdd] | 184 | // subject keyid from cert if it wasn't passed in |
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| 185 | if (opts->subject_cert) { |
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| 186 | certificate_t *subject = cert_from_file(opts->subject_cert); |
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| 187 | subject_id = cert_keyid(subject); |
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| 188 | DESTROY_IF(subject); |
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| 189 | } |
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[085f159] | 190 | |
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| 191 | // build the role encoding |
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| 192 | int role_encoding_len = 1; // for nul terminator |
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| 193 | role_encoding_len += strlen(issuer_id) + 1 + strlen(opts->role); |
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| 194 | role_encoding_len += sizeof(ROLE_SEPARATOR) - 1; |
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| 195 | role_encoding_len += strlen(subject_id); |
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| 196 | if (opts->subject_role) |
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| 197 | role_encoding_len += 1 + strlen(opts->subject_role); |
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| 198 | |
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| 199 | char *role_encoding = xmalloc(role_encoding_len); |
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| 200 | role_encoding[0] = '\0'; |
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| 201 | |
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| 202 | sprintf(role_encoding, "%s.%s" ROLE_SEPARATOR "%s", issuer_id, opts->role, subject_id); |
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| 203 | if (opts->subject_role) { |
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| 204 | strcat(role_encoding, "."); |
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| 205 | strcat(role_encoding, opts->subject_role); |
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| 206 | } |
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| 207 | |
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| 208 | free(issuer_id); |
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[ee5afdd] | 209 | |
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| 210 | // if opts->subject_id, the memory will be freed in main |
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| 211 | if (opts->subject_cert) |
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| 212 | free(subject_id); |
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[085f159] | 213 | |
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| 214 | // create attribute cert |
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| 215 | time_t not_before = time(NULL); |
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| 216 | time_t not_after = not_before + opts->validity * 3600 * 60 * 60; |
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| 217 | chunk_t serial = generate_serial(); |
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| 218 | |
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| 219 | certificate_t *attr_cert = lib->creds->create(lib->creds, |
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| 220 | CRED_CERTIFICATE, CERT_X509_AC, |
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| 221 | BUILD_CERT, issuer, |
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| 222 | BUILD_NOT_BEFORE_TIME, not_before, |
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| 223 | BUILD_NOT_AFTER_TIME, not_after, |
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| 224 | BUILD_SERIAL, serial, |
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| 225 | BUILD_IETF_GROUP_ATTR, role_encoding, |
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| 226 | BUILD_SIGNING_CERT, issuer, |
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| 227 | BUILD_SIGNING_KEY, key, |
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| 228 | BUILD_END |
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| 229 | ); |
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| 230 | if (attr_cert == NULL) |
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| 231 | errx(1, "Couldn't build attribute cert"); |
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| 232 | |
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| 233 | // write to file |
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| 234 | chunk_t encoding = attr_cert->get_encoding(attr_cert); |
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| 235 | |
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| 236 | FILE *out = fopen(opts->out, "w"); |
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| 237 | if (out == NULL) |
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| 238 | err(1, "Can't open attribute cert output file %s", opts->out); |
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| 239 | fwrite(encoding.ptr, encoding.len, 1, out); |
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| 240 | fclose(out); |
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| 241 | |
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| 242 | free(role_encoding); |
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| 243 | free(serial.ptr); |
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| 244 | DESTROY_IF(attr_cert); |
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| 245 | DESTROY_IF(issuer); |
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| 246 | DESTROY_IF(key); |
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| 247 | } |
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