[aa33ad9] | 1 | #include <assert.h> |
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| 2 | #include <ctype.h> |
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| 3 | #include <string.h> |
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| 4 | #include <time.h> |
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| 5 | |
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[3a33812] | 6 | #include "libcreddy_common.h" |
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[aa33ad9] | 7 | |
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| 8 | #define ROLE_SEPARATOR " <- " |
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| 9 | #define INTERSECTION_SEP " & " |
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| 10 | #define SHA1_LENGTH 40 |
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| 11 | |
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| 12 | struct _creddy_attribute_t { |
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| 13 | creddy_id_t *issuer; |
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| 14 | char *role; |
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| 15 | int validity; |
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| 16 | |
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| 17 | char **subject; |
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| 18 | int num_subjects; |
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| 19 | int size_subjects; |
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| 20 | int total_len; // total length of all subject strings |
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| 21 | |
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| 22 | certificate_t *cert; // NULL until baked |
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| 23 | }; |
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| 24 | |
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| 25 | static char *_validate_principal(char *keyid); |
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| 26 | static void _append(creddy_attribute_t *attr, char *subject); |
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| 27 | char *_get_role_encoding(creddy_attribute_t *attr); |
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| 28 | |
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| 29 | int creddy_attribute_create(creddy_attribute_t **ret, creddy_id_t *issuer, char *role, int validity) { |
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| 30 | if (creddy_id_privkey(issuer) == NULL) |
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| 31 | return CREDDY_ATTRIBUTE_ISSUER_NOKEY; |
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[3a33812] | 32 | if (!creddy_clean_name(role)) |
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[aa33ad9] | 33 | return CREDDY_ATTRIBUTE_INVALID_ROLE; |
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| 34 | if (validity < 0) |
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| 35 | return CREDDY_ATTRIBUTE_INVALID_VALIDITY; |
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| 36 | |
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[3a33812] | 37 | creddy_attribute_t *attr = creddy_xmalloc(sizeof(creddy_attribute_t)); |
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[2a20fa0] | 38 | attr->issuer = creddy_id_dup(issuer); |
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[3a33812] | 39 | attr->role = creddy_xstrdup(role); |
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[aa33ad9] | 40 | attr->validity = validity; |
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| 41 | |
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| 42 | attr->num_subjects = 0; |
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| 43 | attr->size_subjects = 4; |
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[3a33812] | 44 | attr->subject = creddy_xmalloc(sizeof(char *) * attr->size_subjects); |
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[aa33ad9] | 45 | attr->total_len = 0; |
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| 46 | |
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| 47 | // NULL until baked |
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| 48 | attr->cert = NULL; |
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| 49 | |
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| 50 | *ret = attr; |
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| 51 | return CREDDY_SUCCESS; |
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| 52 | } |
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| 53 | |
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| 54 | int creddy_attribute_principal(creddy_attribute_t *attr, char *keyid) { |
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| 55 | char *copy = _validate_principal(keyid); |
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| 56 | if (copy == NULL) |
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| 57 | return 0; |
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| 58 | |
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| 59 | _append(attr, copy); |
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| 60 | return 1; |
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| 61 | } |
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| 62 | |
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| 63 | int creddy_attribute_role(creddy_attribute_t *attr, char *keyid, char *role) { |
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[3a33812] | 64 | if (!creddy_clean_name(role)) |
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[aa33ad9] | 65 | return 0; |
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| 66 | |
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| 67 | char *copy = _validate_principal(keyid); |
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| 68 | if (copy == NULL) |
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| 69 | return 0; |
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| 70 | |
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| 71 | int len = strlen(copy) + strlen(role) + strlen(ROLE_SEPARATOR) + 1; |
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[3a33812] | 72 | copy = creddy_xrealloc(copy, len); |
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[aa33ad9] | 73 | strcat(copy, "."); |
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| 74 | strcat(copy, role); |
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| 75 | |
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| 76 | _append(attr, copy); |
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| 77 | return 1; |
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| 78 | } |
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| 79 | |
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| 80 | int creddy_attribute_linking_role(creddy_attribute_t *attr, char *keyid, char *role, char *linked) { |
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[3a33812] | 81 | if (!creddy_clean_name(role) || !creddy_clean_name(linked)) |
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[aa33ad9] | 82 | return 0; |
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| 83 | |
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| 84 | char *copy = _validate_principal(keyid); |
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| 85 | if (copy == NULL) |
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| 86 | return 0; |
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| 87 | |
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[bf7498b] | 88 | int len = strlen(copy) + strlen(role) + strlen(linked) + strlen(ROLE_SEPARATOR) + 2; |
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[3a33812] | 89 | copy = creddy_xrealloc(copy, len); |
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[aa33ad9] | 90 | strcat(copy, "."); |
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| 91 | strcat(copy, role); |
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| 92 | strcat(copy, "."); |
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| 93 | strcat(copy, linked); |
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| 94 | |
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| 95 | _append(attr, copy); |
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| 96 | return 1; |
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| 97 | } |
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| 98 | |
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| 99 | int creddy_attribute_bake(creddy_attribute_t *attr) { |
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| 100 | if (attr->num_subjects == 0) |
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| 101 | return 0; |
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| 102 | |
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[11e3eb7] | 103 | libabac_init(); |
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[9d767d1] | 104 | |
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[aa33ad9] | 105 | char *role_encoding = _get_role_encoding(attr); |
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| 106 | |
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| 107 | // create attribute cert |
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| 108 | time_t not_before = time(NULL); |
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| 109 | time_t not_after = not_before + attr->validity * 3600 * 60 * 60; |
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| 110 | chunk_t serial = creddy_generate_serial(); |
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| 111 | |
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| 112 | certificate_t *attr_cert = lib->creds->create(lib->creds, |
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| 113 | CRED_CERTIFICATE, CERT_X509_AC, |
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| 114 | BUILD_CERT, creddy_id_cert(attr->issuer), |
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| 115 | BUILD_NOT_BEFORE_TIME, not_before, |
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| 116 | BUILD_NOT_AFTER_TIME, not_after, |
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| 117 | BUILD_SERIAL, serial, |
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| 118 | BUILD_IETF_GROUP_ATTR, role_encoding, |
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| 119 | BUILD_SIGNING_CERT, creddy_id_cert(attr->issuer), |
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| 120 | BUILD_SIGNING_KEY, creddy_id_privkey(attr->issuer), |
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| 121 | BUILD_END |
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| 122 | ); |
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| 123 | if (attr_cert == NULL) |
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| 124 | return 0; |
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| 125 | |
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| 126 | attr->cert = attr_cert; |
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| 127 | |
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| 128 | free(role_encoding); |
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| 129 | free(serial.ptr); |
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| 130 | return 1; |
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| 131 | } |
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| 132 | |
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[11e3eb7] | 133 | int creddy_attribute_cert_chunk(creddy_attribute_t *attr, abac_chunk_t *chunk) { |
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| 134 | if (attr->cert == NULL) |
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| 135 | return 0; |
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| 136 | |
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| 137 | chunk_t encoding = attr->cert->get_encoding(attr->cert); |
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| 138 | chunk->ptr = encoding.ptr; chunk->len = encoding.len; |
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| 139 | return 1; |
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| 140 | } |
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| 141 | |
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[e02c742] | 142 | int creddy_attribute_baked(creddy_attribute_t *attr) { |
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| 143 | return attr->cert != NULL; |
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| 144 | } |
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| 145 | |
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[78358ab] | 146 | // returns 0 if the cert hasn't been baked |
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[aa33ad9] | 147 | int creddy_attribute_write(creddy_attribute_t *attr, FILE *out) { |
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| 148 | assert(attr != NULL); |
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| 149 | |
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| 150 | if (attr->cert == NULL) |
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| 151 | return 0; |
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| 152 | |
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| 153 | // write to file |
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| 154 | chunk_t encoding = attr->cert->get_encoding(attr->cert); |
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| 155 | fwrite(encoding.ptr, encoding.len, 1, out); |
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| 156 | free(encoding.ptr); |
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| 157 | |
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| 158 | return 1; |
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| 159 | } |
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| 160 | |
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| 161 | void creddy_attribute_free(creddy_attribute_t *attr) { |
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| 162 | int i; |
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| 163 | |
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| 164 | if (attr == NULL) |
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| 165 | return; |
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| 166 | |
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| 167 | creddy_id_free(attr->issuer); |
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| 168 | free(attr->role); |
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| 169 | DESTROY_IF(attr->cert); |
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| 170 | |
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| 171 | // free all the subjects |
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| 172 | for (i = 0; i < attr->num_subjects; ++i) |
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| 173 | free(attr->subject[i]); |
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| 174 | free(attr->subject); |
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| 175 | |
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| 176 | free(attr); |
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| 177 | } |
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| 178 | |
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| 179 | // |
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| 180 | // Helper functions below |
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| 181 | // |
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| 182 | |
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| 183 | // validate a princpal's name |
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| 184 | // makes sure it's a valid SHA1 identifier |
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| 185 | // return values: |
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| 186 | // success: malloc'd copy with all hex digits lowercase |
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| 187 | // fail: NULL |
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| 188 | static char *_validate_principal(char *keyid) { |
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| 189 | int i; |
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| 190 | char *copy = NULL; |
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| 191 | |
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| 192 | if (strlen(keyid) != SHA1_LENGTH) |
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| 193 | return NULL; |
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| 194 | |
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[3a33812] | 195 | copy = creddy_xstrdup(keyid); |
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[aa33ad9] | 196 | for (i = 0; i < SHA1_LENGTH; ++i) { |
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| 197 | copy[i] = tolower(copy[i]); |
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| 198 | if (!isxdigit(copy[i])) |
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| 199 | goto error; |
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| 200 | } |
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| 201 | |
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| 202 | return copy; |
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| 203 | |
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| 204 | error: |
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| 205 | free(copy); |
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| 206 | return NULL; |
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| 207 | } |
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| 208 | |
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| 209 | static void _append(creddy_attribute_t *attr, char *subject) { |
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| 210 | // expand the array if necessary |
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| 211 | if (attr->num_subjects == attr->size_subjects) { |
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| 212 | attr->size_subjects *= 2; |
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[3a33812] | 213 | attr->subject = creddy_xrealloc(attr->subject, attr->size_subjects * sizeof(creddy_attribute_t)); |
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[aa33ad9] | 214 | } |
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| 215 | |
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| 216 | attr->subject[attr->num_subjects++] = subject; |
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| 217 | attr->total_len += strlen(subject); |
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| 218 | } |
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| 219 | |
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| 220 | char *_get_role_encoding(creddy_attribute_t *attr) { |
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| 221 | int i, num_subjects; |
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| 222 | |
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| 223 | num_subjects = attr->num_subjects; |
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| 224 | |
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| 225 | int len = SHA1_LENGTH + 1 + strlen(attr->role) + strlen(ROLE_SEPARATOR); |
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| 226 | len += attr->total_len + num_subjects * strlen(INTERSECTION_SEP); |
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| 227 | |
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[3a33812] | 228 | char *encoding = creddy_xmalloc(len); |
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[aa33ad9] | 229 | sprintf(encoding, "%s.%s" ROLE_SEPARATOR, creddy_id_keyid(attr->issuer), attr->role); |
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| 230 | |
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| 231 | for (i = 0; i < num_subjects; ++i) { |
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| 232 | strcat(encoding, attr->subject[i]); |
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| 233 | if (i < num_subjects - 1) |
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| 234 | strcat(encoding, INTERSECTION_SEP); |
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| 235 | } |
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| 236 | |
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| 237 | return encoding; |
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| 238 | } |
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