proposal: Prevent selection of duplicate key exchange methods

All additional (and the initial) key exchanges must use a different method.

diff --git a/src/libstrongswan/crypto/proposal/proposal.c b/src/libstrongswan/crypto/proposal/proposal.c
index 606aa4ca37784f587eca5cb1063a4c7267ad2463..869f08f098179763d464bab5688bc349ae13464f 100644 (file)
--- a/src/libstrongswan/crypto/proposal/proposal.c
+++ b/src/libstrongswan/crypto/proposal/proposal.c
@@ -21,6 +21,7 @@
 #include "proposal.h"
 
 #include <collections/array.h>
+#include <collections/hashtable.h>
 #include <utils/identification.h>
 
 #include <crypto/transform.h>
@@ -316,7 +317,7 @@ METHOD(proposal_t, promote_transform, bool,
  */
 static bool select_algo(private_proposal_t *this, proposal_t *other,
                                                transform_type_t type, proposal_selection_flag_t flags,
-                                               bool log, uint16_t *alg, uint16_t *ks)
+                                               hashtable_t *kes, bool log, uint16_t *alg, uint16_t *ks)
 {
        enumerator_t *e1, *e2;
        uint16_t alg1, alg2, ks1, ks2;
@@ -359,9 +360,13 @@ static bool select_algo(private_proposal_t *this, proposal_t *other,
 
        e1->destroy(e1);
        e1 = create_enumerator(this, type);
-       /* compare algs, order of algs in "first" is preferred */
+       /* compare algs, order of algs in "e1" is preferred */
        while (!found && e1->enumerate(e1, &alg1, &ks1))
        {
+               if (is_ke_transform(type) && kes->get(kes, (void*)(uintptr_t)alg1))
+               {
+                       continue;
+               }
                e2->destroy(e2);
                e2 = other->create_enumerator(other, type);
                while (e2->enumerate(e2, &alg2, &ks2))
@@ -390,6 +395,23 @@ static bool select_algo(private_proposal_t *this, proposal_t *other,
        return found;
 }
 
+/**
+ * Hash an algorithm identifier
+ */
+static u_int hash_alg(const void *key)
+{
+       uint16_t alg = (uint16_t)(uintptr_t)key;
+       return chunk_hash(chunk_from_thing(alg));
+}
+
+/**
+ * Compare two algorithm identifiers
+ */
+static bool equals_alg(const void *key, const void *other_key)
+{
+       return (uint16_t)(uintptr_t)key == (uint16_t)(uintptr_t)other_key;
+}
+
 /**
  * Select algorithms from the given proposals, if selected is given, the result
  * is stored there and errors are logged.
@@ -398,10 +420,13 @@ static bool select_algos(private_proposal_t *this, proposal_t *other,
                                                 proposal_t *selected, proposal_selection_flag_t flags)
 {
        transform_type_t type;
+       hashtable_t *kes;
        array_t *types;
        bool skip_integrity = FALSE;
        int i;
 
+       kes = hashtable_create(hash_alg, equals_alg, 8);
+
        types = merge_types(this, (private_proposal_t*)other);
        for (i = 0; i < array_count(types); i++)
        {
@@ -416,7 +441,8 @@ static bool select_algos(private_proposal_t *this, proposal_t *other,
                {
                        continue;
                }
-               if (select_algo(this, other, type, flags, selected != NULL, &alg, &ks))
+               if (select_algo(this, other, type, flags, kes, selected != NULL,
+                                               &alg, &ks))
                {
                        if (alg == 0 && type != EXTENDED_SEQUENCE_NUMBERS)
                        {       /* 0 is "valid" for extended sequence numbers, for other
@@ -427,6 +453,10 @@ static bool select_algos(private_proposal_t *this, proposal_t *other,
                        {
                                selected->add_algorithm(selected, type, alg, ks);
                        }
+                       if (is_ke_transform(type))
+                       {
+                               kes->put(kes, (void*)(uintptr_t)alg, (void*)(uintptr_t)alg);
+                       }
                        if (type == ENCRYPTION_ALGORITHM &&
                                encryption_algorithm_is_aead(alg))
                        {
@@ -442,10 +472,12 @@ static bool select_algos(private_proposal_t *this, proposal_t *other,
                                         type);
                        }
                        array_destroy(types);
+                       kes->destroy(kes);
                        return FALSE;
                }
        }
        array_destroy(types);
+       kes->destroy(kes);
        return TRUE;
 }
 

diff --git a/src/libstrongswan/tests/suites/test_proposal.c b/src/libstrongswan/tests/suites/test_proposal.c
index 7798bfb24af7abdc7829a6a5c8ad50fcafe732b1..78724bb6f1e6c4d57cbdff167e2dbfefbbe7b12c 100644 (file)
--- a/src/libstrongswan/tests/suites/test_proposal.c
+++ b/src/libstrongswan/tests/suites/test_proposal.c
@@ -143,6 +143,28 @@ static struct {
        { PROTO_IKE, "aes128-sha256-modp3072", "aes128-sha256-modp3072", "aes128-sha256-modp3072" },
        { PROTO_IKE, "aes128-sha256-modp3072", "aes128-sha256-modp3072-none", "aes128-sha256-modp3072" },
        { PROTO_IKE, "aes128-sha256-modp3072-none", "aes128-sha256-modp3072", "aes128-sha256-modp3072" },
+       { PROTO_IKE, "aes128-sha256-modp3072-ke1_modp3072",
+                                "aes128-sha256-modp3072-ke1_modp3072", NULL },
+       { PROTO_IKE, "aes128-sha256-modp3072-ecp256-ecp384-ke1_modp3072-ke1_ecp256-ke1_ecp384-ke2_modp3072-ke2_ecp256-ke2_ecp384",
+                                "aes128-sha256-modp3072-ecp256-ecp384-ke1_modp3072-ke1_ecp256-ke1_ecp384-ke2_modp3072-ke2_ecp256-ke2_ecp384",
+                                "aes128-sha256-modp3072-ke1_ecp256-ke2_ecp384" },
+       { PROTO_IKE, "aes128-sha256-modp3072-ke1_modp3072-ke1_none",
+                                "aes128-sha256-modp3072-ke1_modp3072-ke1_none",
+                                "aes128-sha256-modp3072" },
+       { PROTO_IKE, "aes128-sha256-modp3072-ke1_modp3072-ke1_none-ke2_modp3072-ke2_none",
+                                "aes128-sha256-modp3072-ke1_modp3072-ke1_none-ke2_modp3072-ke2_none",
+                                "aes128-sha256-modp3072" },
+       { PROTO_IKE, "aes128-sha256-modp3072-ke1_modp3072-ke1_ecp256",
+                                "aes128-sha256-modp3072-ke1_modp3072-ke1_ecp256",
+                                "aes128-sha256-modp3072-ke1_ecp256" },
+       { PROTO_IKE, "aes128-sha256-modp3072-ke1_modp3072-ke1_ecp256",
+                                "aes128-sha256-modp3072-ke1_ecp256",
+                                "aes128-sha256-modp3072-ke1_ecp256" },
+       { PROTO_IKE, "aes128-sha256-modp3072-ke1_ecp256",
+                                "aes128-sha256-modp3072-ke1_modp3072-ke1_ecp256",
+                                "aes128-sha256-modp3072-ke1_ecp256" },
+       { PROTO_IKE, "aes128-sha256-ecp256-ke1_modp3072",
+                                "aes128-sha256-modp3072-ecp256-ke1_ecp256-ke2_ecp384", NULL },
 };
 
 START_TEST(test_select)