X-Git-Url: http://www.project-moonshot.org/gitweb/?a=blobdiff_plain;f=util_krb.c;h=82d6c500488253856c87674b2a66571e0fddae1a;hb=163856b1a70d7773c46d4ea5495b85c4dce0f089;hp=02aa92bde4434f2b14cd236005a66a8efc22acc0;hpb=07abfd2c1b6158d8e7fb8519c2145b31c01a106b;p=mech_eap.orig

diff --git a/util_krb.c b/util_krb.c
index 02aa92b..82d6c50 100644
--- a/util_krb.c
+++ b/util_krb.c
@@ -30,6 +30,10 @@
  * SUCH DAMAGE.
  */
 
+/*
+ * Kerberos 5 helpers.
+ */
+
 #include "gssapiP_eap.h"
 
 static GSSEAP_THREAD_ONCE krbContextKeyOnce = GSSEAP_ONCE_INITIALIZER;
@@ -73,92 +77,341 @@ gssEapKerberosInit(OM_uint32 *minor, krb5_context *context)
 }
 
 /*
- * Derive a key for RFC 4121 use by using the following
- * derivation function:
+ * Derive a key K for RFC 4121 use by using the following
+ * derivation function (based on RFC 4402);
  *
- *    random-to-key(prf(random-to-key([e]msk), "rfc4121-gss-eap"))
- *
- * where random-to-key and prf are defined in RFC 3961.
+ * KMSK = random-to-key(MSK)
+ * Tn = pseudo-random(KMSK, n || "rfc4121-gss-eap")
+ * L = output key size
+ * K = truncate(L, T1 || T2 || .. || Tn)
  */
 OM_uint32
-gssEapDeriveRFC3961Key(OM_uint32 *minor,
-                       gss_buffer_t msk,
-                       krb5_enctype enctype,
+gssEapDeriveRfc3961Key(OM_uint32 *minor,
+                       const unsigned char *inputKey,
+                       size_t inputKeyLength,
+                       krb5_enctype encryptionType,
                        krb5_keyblock *pKey)
 {
-    krb5_context context;
-    krb5_data data, prf;
+    krb5_context krbContext;
+#ifndef HAVE_HEIMDAL_VERSION
+    krb5_data data;
+#endif
+    krb5_data ns, t, prfOut;
     krb5_keyblock kd;
     krb5_error_code code;
-    size_t keybytes, keylength, prflength;
+    size_t randomLength, keyLength, prfLength;
+    unsigned char constant[4 + sizeof("rfc4121-gss-eap") - 1], *p;
+    ssize_t i, remain;
+
+    assert(encryptionType != ENCTYPE_NULL);
 
     memset(pKey, 0, sizeof(*pKey));
 
-    GSSEAP_KRB_INIT(&context);
+    GSSEAP_KRB_INIT(&krbContext);
 
-    kd.contents = NULL;
-    kd.length = 0;
-    KRB_KEYTYPE(&kd) = enctype;
+    KRB_KEY_INIT(&kd);
+    KRB_KEY_TYPE(&kd) = encryptionType;
 
-    prf.data = NULL;
-    prf.length = 0;
+    t.data = NULL;
+    t.length = 0;
 
-    code = krb5_c_keylengths(context, enctype, &keybytes, &keylength);
+    prfOut.data = NULL;
+    prfOut.length = 0;
+
+    code = krb5_c_keylengths(krbContext, encryptionType,
+                             &randomLength, &keyLength);
     if (code != 0)
         goto cleanup;
 
-    data.length = msk->length;
-    data.data = (char *)msk->value;
-
-    kd.contents = GSSEAP_MALLOC(keylength);
-    if (kd.contents == NULL) {
+    KRB_KEY_DATA(&kd) = GSSEAP_MALLOC(keyLength);
+    if (KRB_KEY_DATA(&kd) == NULL) {
         code = ENOMEM;
         goto cleanup;
     }
-    kd.length = keylength;
+    KRB_KEY_LENGTH(&kd) = keyLength;
 
     /* Convert MSK into a Kerberos key */
-    code = krb5_c_random_to_key(context, enctype, &data, &kd);
+#ifdef HAVE_HEIMDAL_VERSION
+    code = krb5_random_to_key(krbContext, encryptionType, inputKey,
+                              MIN(inputKeyLength, randomLength), &kd);
+#else
+    data.length = MIN(inputKeyLength, randomLength);
+    data.data = (char *)inputKey;
+
+    code = krb5_c_random_to_key(krbContext, encryptionType, &data, &kd);
+#endif
     if (code != 0)
         goto cleanup;
 
-    data.length = sizeof("rfc4121-gss-eap") - 1;
-    data.data = "rfc4121-gss-eap";
+    memset(&constant[0], 0, 4);
+    memcpy(&constant[4], "rfc4121-gss-eap", sizeof("rfc4121-gss-eap") - 1);
+
+    ns.length = sizeof(constant);
+    ns.data = (char *)constant;
 
     /* Plug derivation constant and key into PRF */
-    code = krb5_c_prf_length(context, enctype, &prflength);
+    code = krb5_c_prf_length(krbContext, encryptionType, &prfLength);
     if (code != 0)
         goto cleanup;
 
-    prf.length = prflength;
-    prf.data = GSSEAP_MALLOC(prflength);
-    if (data.data == NULL) {
+    t.length = prfLength;
+    t.data = GSSEAP_MALLOC(t.length);
+    if (t.data == NULL) {
         code = ENOMEM;
         goto cleanup;
     }
 
-    code = krb5_c_prf(context, &kd, &data, &prf);
-    if (code != 0)
+    prfOut.length = randomLength;
+    prfOut.data = GSSEAP_MALLOC(prfOut.length);
+    if (prfOut.data == NULL) {
+        code = ENOMEM;
         goto cleanup;
+    }
+
+    for (i = 0, p = (unsigned char *)prfOut.data, remain = randomLength;
+         remain > 0;
+         p += t.length, remain -= t.length, i++)
+    {
+        store_uint32_be(i, ns.data);
+
+        code = krb5_c_prf(krbContext, &kd, &ns, &t);
+        if (code != 0)
+            goto cleanup;
+
+        memcpy(p, t.data, MIN(t.length, remain));
+     }
 
     /* Finally, convert PRF output into a new key which we will return */
-    code = krb5_c_random_to_key(context, enctype, &prf, &kd);
+#ifdef HAVE_HEIMDAL_VERSION
+    code = krb5_random_to_key(krbContext, encryptionType,
+                              prfOut.data, prfOut.length, &kd);
+#else
+    code = krb5_c_random_to_key(krbContext, encryptionType, &prfOut, &kd);
+#endif
     if (code != 0)
         goto cleanup;
 
     *pKey = kd;
-    kd.contents = NULL;
+    KRB_KEY_DATA(&kd) = NULL;
 
 cleanup:
-    if (kd.contents != NULL) {
-        memset(kd.contents, 0, kd.length);
-        GSSEAP_FREE(kd.contents);
+    if (KRB_KEY_DATA(&kd) != NULL) {
+        memset(KRB_KEY_DATA(&kd), 0, KRB_KEY_LENGTH(&kd));
+        GSSEAP_FREE(KRB_KEY_DATA(&kd));
     }
-    if (prf.data != NULL) {
-        memset(prf.data, 0, prf.length);
-        GSSEAP_FREE(prf.data);
+    if (t.data != NULL) {
+        memset(t.data, 0, t.length);
+        GSSEAP_FREE(t.data);
+    }
+    if (prfOut.data != NULL) {
+        memset(prfOut.data, 0, prfOut.length);
+        GSSEAP_FREE(prfOut.data);
     }
-
     *minor = code;
     return (code == 0) ? GSS_S_COMPLETE : GSS_S_FAILURE;
 }
+
+#ifdef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
+extern krb5_error_code
+krb5int_c_mandatory_cksumtype(krb5_context, krb5_enctype, krb5_cksumtype *);
+#endif
+
+OM_uint32
+rfc3961ChecksumTypeForKey(OM_uint32 *minor,
+                          krb5_keyblock *key,
+                          krb5_cksumtype *cksumtype)
+{
+    krb5_context krbContext;
+#ifndef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
+    krb5_data data;
+    krb5_checksum cksum;
+#endif
+
+    GSSEAP_KRB_INIT(&krbContext);
+
+#ifdef HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE
+    *minor = krb5int_c_mandatory_cksumtype(krbContext, KRB_KEY_TYPE(key),
+                                           cksumtype);
+    if (*minor != 0)
+        return GSS_S_FAILURE;
+#else
+    data.length = 0;
+    data.data = NULL;
+
+    memset(&cksum, 0, sizeof(cksum));
+
+    /*
+     * This is a complete hack but it's the only way to work with
+     * MIT Kerberos pre-1.9 without using private API, as it does
+     * not support passing in zero as the checksum type.
+     */
+    *minor = krb5_c_make_checksum(krbContext, 0, key, 0, &data, &cksum);
+    if (*minor != 0)
+        return GSS_S_FAILURE;
+
+#ifdef HAVE_HEIMDAL_VERSION
+    *cksumtype = cksum.cksumtype;
+#else
+    *cksumtype = cksum.checksum_type;
+#endif
+
+    krb5_free_checksum_contents(krbContext, &cksum);
+#endif /* HAVE_KRB5INT_C_MANDATORY_CKSUMTYPE */
+
+    if (!krb5_c_is_keyed_cksum(*cksumtype)) {
+        *minor = KRB5KRB_AP_ERR_INAPP_CKSUM;
+        return GSS_S_FAILURE;
+    }
+
+    return GSS_S_COMPLETE;
+}
+
+#ifdef HAVE_HEIMDAL_VERSION
+static heim_general_string krbAnonymousPrincipalComponents[] =
+    { KRB5_WELLKNOWN_NAME, KRB5_ANON_NAME };
+
+static const Principal krbAnonymousPrincipalData = {
+    { KRB5_NT_WELLKNOWN, { 2, krbAnonymousPrincipalComponents } },
+    "WELLKNOWN:ANONYMOUS"
+};
+#endif
+
+krb5_const_principal
+krbAnonymousPrincipal(void)
+{
+#ifdef HAVE_HEIMDAL_VERSION
+    return &krbAnonymousPrincipalData;
+#else
+    return krb5_anonymous_principal();
+#endif
+}
+
+krb5_error_code
+krbCryptoLength(krb5_context krbContext,
+#ifdef HAVE_HEIMDAL_VERSION
+                krb5_crypto krbCrypto,
+#else
+                krb5_keyblock *key,
+#endif
+                int type,
+                size_t *length)
+{
+#ifdef HAVE_HEIMDAL_VERSION
+    return krb5_crypto_length(krbContext, krbCrypto, type, length);
+#else
+    unsigned int len;
+    krb5_error_code code;
+
+    code = krb5_c_crypto_length(krbContext, KRB_KEY_TYPE(key), type, &len);
+    if (code == 0)
+        *length = (size_t)len;
+
+    return code;
+#endif
+}
+
+krb5_error_code
+krbPaddingLength(krb5_context krbContext,
+#ifdef HAVE_HEIMDAL_VERSION
+                 krb5_crypto krbCrypto,
+#else
+                 krb5_keyblock *key,
+#endif
+                 size_t dataLength,
+                 size_t *padLength)
+{
+    krb5_error_code code;
+#ifdef HAVE_HEIMDAL_VERSION
+    size_t headerLength, paddingLength;
+
+    code = krbCryptoLength(krbContext, krbCrypto,
+                           KRB5_CRYPTO_TYPE_HEADER, &headerLength);
+    if (code != 0)
+        return code;
+
+    dataLength += headerLength;
+
+    code = krb5_crypto_length(krbContext, krbCrypto,
+                              KRB5_CRYPTO_TYPE_PADDING, &paddingLength);
+    if (code != 0)
+        return code;
+
+    if (paddingLength != 0 && (dataLength % paddingLength) != 0)
+        *padLength = paddingLength - (dataLength % paddingLength);
+    else
+        *padLength = 0;
+
+    return 0;
+#else
+    unsigned int pad;
+
+    code = krb5_c_padding_length(krbContext, KRB_KEY_TYPE(key), dataLength, &pad);
+    if (code == 0)
+        *padLength = (size_t)pad;
+
+    return code;
+#endif /* HAVE_HEIMDAL_VERSION */
+}
+
+krb5_error_code
+krbBlockSize(krb5_context krbContext,
+#ifdef HAVE_HEIMDAL_VERSION
+                 krb5_crypto krbCrypto,
+#else
+                 krb5_keyblock *key,
+#endif
+                 size_t *blockSize)
+{
+#ifdef HAVE_HEIMDAL_VERSION
+    return krb5_crypto_getblocksize(krbContext, krbCrypto, blockSize);
+#else
+    return krb5_c_block_size(krbContext, KRB_KEY_TYPE(key), blockSize);
+#endif
+}
+
+krb5_error_code
+krbEnctypeToString(krb5_context krbContext,
+                   krb5_enctype enctype,
+                   const char *prefix,
+                   gss_buffer_t string)
+{
+    krb5_error_code code;
+#ifdef HAVE_HEIMDAL_VERSION
+    char *enctypeBuf = NULL;
+#else
+    char enctypeBuf[128];
+#endif
+    size_t prefixLength, enctypeLength;
+
+#ifdef HAVE_HEIMDAL_VERSION
+    code = krb5_enctype_to_string(krbContext, enctype, &enctypeBuf);
+#else
+    code = krb5_enctype_to_name(enctype, 0, enctypeBuf, sizeof(enctypeBuf));
+#endif
+    if (code != 0)
+        return code;
+
+    prefixLength = (prefix != NULL) ? strlen(prefix) : 0;
+    enctypeLength = strlen(enctypeBuf);
+
+    string->value = GSSEAP_MALLOC(prefixLength + enctypeLength + 1);
+    if (string->value == NULL) {
+#ifdef HAVE_HEIMDAL_VERSION
+        krb5_xfree(enctypeBuf);
+#endif
+        return ENOMEM;
+    }
+
+    if (prefixLength != 0)
+        memcpy(string->value, prefix, prefixLength);
+    memcpy((char *)string->value + prefixLength, enctypeBuf, enctypeLength);
+
+    string->length = prefixLength + enctypeLength;
+    ((char *)string->value)[string->length] = '\0';
+
+#ifdef HAVE_HEIMDAL_VERSION
+    krb5_xfree(enctypeBuf);
+#endif
+
+    return 0;
+}