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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 for RFC 4121 use by using the following
77 * derivation function:
79 * random-to-key(prf(random-to-key([e]msk), "rfc4121-gss-eap"))
81 * where random-to-key and prf are defined in RFC 3961.
84 gssEapDeriveRfc3961Key(OM_uint32 *minor,
85 const unsigned char *inputKey,
86 size_t inputKeyLength,
87 krb5_enctype encryptionType,
90 krb5_context krbContext;
91 krb5_data data, ns, t, prfOut;
94 size_t randomLength, keyLength, prfLength;
95 unsigned char constant[4 + sizeof("rfc4121-gss-eap") - 1], *p;
98 memset(pKey, 0, sizeof(*pKey));
100 GSSEAP_KRB_INIT(&krbContext);
103 KRB_KEY_TYPE(&kd) = encryptionType;
108 code = krb5_c_keylengths(krbContext, encryptionType,
109 &randomLength, &keyLength);
113 data.length = MIN(inputKeyLength, randomLength);
114 data.data = (char *)inputKey;
116 KRB_KEY_DATA(&kd) = GSSEAP_MALLOC(keyLength);
117 if (KRB_KEY_DATA(&kd) == NULL) {
121 KRB_KEY_LENGTH(&kd) = keyLength;
123 /* Convert MSK into a Kerberos key */
124 code = krb5_c_random_to_key(krbContext, encryptionType, &data, &kd);
128 memset(&constant[0], 0, 4);
129 memcpy(&constant[4], "rfc4121-gss-eap", sizeof("rfc4121-gss-eap") - 1);
131 ns.length = sizeof(constant);
132 ns.data = (char *)constant;
134 /* Plug derivation constant and key into PRF */
135 code = krb5_c_prf_length(krbContext, encryptionType, &prfLength);
139 t.length = prfLength;
140 t.data = GSSEAP_MALLOC(t.length);
141 if (t.data == NULL) {
146 prfOut.length = randomLength;
147 prfOut.data = GSSEAP_MALLOC(prfOut.length);
148 if (prfOut.data == NULL) {
153 for (i = 0, p = (unsigned char *)prfOut.data, remain = randomLength;
155 p += t.length, remain -= t.length, i++)
157 store_uint32_be(i, ns.data);
159 code = krb5_c_prf(krbContext, &kd, &ns, &t);
163 memcpy(p, t.data, MIN(t.length, remain));
166 /* Finally, convert PRF output into a new key which we will return */
167 code = krb5_c_random_to_key(krbContext, encryptionType, &prfOut, &kd);
172 KRB_KEY_DATA(&kd) = NULL;
175 if (KRB_KEY_DATA(&kd) != NULL) {
176 memset(KRB_KEY_DATA(&kd), 0, KRB_KEY_LENGTH(&kd));
177 GSSEAP_FREE(KRB_KEY_DATA(&kd));
179 if (t.data != NULL) {
180 memset(t.data, 0, t.length);
183 if (prfOut.data != NULL) {
184 memset(prfOut.data, 0, prfOut.length);
185 GSSEAP_FREE(prfOut.data);
188 return (code == 0) ? GSS_S_COMPLETE : GSS_S_FAILURE;
191 #ifdef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
192 extern krb5_error_code
193 krb5int_c_mandatory_cksumtype(krb5_context, krb5_enctype, krb5_cksumtype *);
197 rfc3961ChecksumTypeForKey(OM_uint32 *minor,
199 krb5_cksumtype *cksumtype)
201 krb5_context krbContext;
202 #ifndef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
207 GSSEAP_KRB_INIT(&krbContext);
209 #ifdef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
210 *minor = krb5int_c_mandatory_cksumtype(krbContext, KRB_KEY_TYPE(key),
213 return GSS_S_FAILURE;
218 memset(&cksum, 0, sizeof(cksum));
221 * This is a complete hack but it's the only way to work with
222 * MIT Kerberos pre-1.9 without using private API, as it does
223 * not support passing in zero as the checksum type.
225 *minor = krb5_c_make_checksum(krbContext, 0, key, 0, &data, &cksum);
227 return GSS_S_FAILURE;
229 *cksumtype = cksum.checksum_type;
231 krb5_free_checksum_contents(krbContext, &cksum);
232 #endif /* HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE */
234 return GSS_S_COMPLETE;