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33 #include "gssapiP_eap.h"
35 static GSSEAP_THREAD_ONCE krbContextKeyOnce = GSSEAP_ONCE_INITIALIZER;
36 static GSSEAP_THREAD_KEY krbContextKey;
39 destroyKrbContext(void *arg)
41 krb5_context context = (krb5_context)arg;
44 krb5_free_context(context);
48 createKrbContextKey(void)
50 GSSEAP_KEY_CREATE(&krbContextKey, destroyKrbContext);
54 gssEapKerberosInit(OM_uint32 *minor, krb5_context *context)
58 GSSEAP_ONCE(&krbContextKeyOnce, createKrbContextKey);
60 *context = GSSEAP_GETSPECIFIC(krbContextKey);
61 if (*context == NULL) {
62 *minor = krb5_init_context(context);
64 if (GSSEAP_SETSPECIFIC(krbContextKey, *context) != 0) {
66 krb5_free_context(*context);
72 return *minor == 0 ? GSS_S_COMPLETE : GSS_S_FAILURE;
76 * Derive a key K for RFC 4121 use by using the following
77 * derivation function (based on RFC 4402);
79 * KMSK = random-to-key(MSK)
80 * Tn = pseudo-random(KMSK, n || "rfc4121-gss-eap")
82 * K = truncate(L, T1 || T2 || .. || Tn)
85 gssEapDeriveRfc3961Key(OM_uint32 *minor,
86 const unsigned char *inputKey,
87 size_t inputKeyLength,
88 krb5_enctype encryptionType,
91 krb5_context krbContext;
92 krb5_data data, ns, t, prfOut;
95 size_t randomLength, keyLength, prfLength;
96 unsigned char constant[4 + sizeof("rfc4121-gss-eap") - 1], *p;
99 assert(encryptionType != ENCTYPE_NULL);
101 memset(pKey, 0, sizeof(*pKey));
103 GSSEAP_KRB_INIT(&krbContext);
106 KRB_KEY_TYPE(&kd) = encryptionType;
114 code = krb5_c_keylengths(krbContext, encryptionType,
115 &randomLength, &keyLength);
119 data.length = MIN(inputKeyLength, randomLength);
120 data.data = (char *)inputKey;
122 KRB_KEY_DATA(&kd) = GSSEAP_MALLOC(keyLength);
123 if (KRB_KEY_DATA(&kd) == NULL) {
127 KRB_KEY_LENGTH(&kd) = keyLength;
129 /* Convert MSK into a Kerberos key */
130 code = krb5_c_random_to_key(krbContext, encryptionType, &data, &kd);
134 memset(&constant[0], 0, 4);
135 memcpy(&constant[4], "rfc4121-gss-eap", sizeof("rfc4121-gss-eap") - 1);
137 ns.length = sizeof(constant);
138 ns.data = (char *)constant;
140 /* Plug derivation constant and key into PRF */
141 code = krb5_c_prf_length(krbContext, encryptionType, &prfLength);
145 t.length = prfLength;
146 t.data = GSSEAP_MALLOC(t.length);
147 if (t.data == NULL) {
152 prfOut.length = randomLength;
153 prfOut.data = GSSEAP_MALLOC(prfOut.length);
154 if (prfOut.data == NULL) {
159 for (i = 0, p = (unsigned char *)prfOut.data, remain = randomLength;
161 p += t.length, remain -= t.length, i++)
163 store_uint32_be(i, ns.data);
165 code = krb5_c_prf(krbContext, &kd, &ns, &t);
169 memcpy(p, t.data, MIN(t.length, remain));
172 /* Finally, convert PRF output into a new key which we will return */
173 code = krb5_c_random_to_key(krbContext, encryptionType, &prfOut, &kd);
178 KRB_KEY_DATA(&kd) = NULL;
181 if (KRB_KEY_DATA(&kd) != NULL) {
182 memset(KRB_KEY_DATA(&kd), 0, KRB_KEY_LENGTH(&kd));
183 GSSEAP_FREE(KRB_KEY_DATA(&kd));
185 if (t.data != NULL) {
186 memset(t.data, 0, t.length);
189 if (prfOut.data != NULL) {
190 memset(prfOut.data, 0, prfOut.length);
191 GSSEAP_FREE(prfOut.data);
194 return (code == 0) ? GSS_S_COMPLETE : GSS_S_FAILURE;
197 #ifdef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
198 extern krb5_error_code
199 krb5int_c_mandatory_cksumtype(krb5_context, krb5_enctype, krb5_cksumtype *);
203 rfc3961ChecksumTypeForKey(OM_uint32 *minor,
205 krb5_cksumtype *cksumtype)
207 krb5_context krbContext;
208 #ifndef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
213 GSSEAP_KRB_INIT(&krbContext);
215 #ifdef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
216 *minor = krb5int_c_mandatory_cksumtype(krbContext, KRB_KEY_TYPE(key),
219 return GSS_S_FAILURE;
224 memset(&cksum, 0, sizeof(cksum));
227 * This is a complete hack but it's the only way to work with
228 * MIT Kerberos pre-1.9 without using private API, as it does
229 * not support passing in zero as the checksum type.
231 *minor = krb5_c_make_checksum(krbContext, 0, key, 0, &data, &cksum);
233 return GSS_S_FAILURE;
235 *cksumtype = cksum.checksum_type;
237 krb5_free_checksum_contents(krbContext, &cksum);
238 #endif /* HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE */
240 return GSS_S_COMPLETE;