DPP: Replace dpp_bootstrap_key_der() with crypto_ec_key_get_subject_public_key()

As BoringSSL version of i2d_PUBKEY() doesn't respect the
POINT_CONVERSION_COMPRESSED flag redefine a specific
crypto_ec_key_get_subject_public_key() version for BoringSSL based on
dpp_bootstrap_key_der().

The only other user of crypto_ec_key_get_subject_public_key() is SAE-PK
for which the public key should also be formatted using compressed
format.

Signed-off-by: Cedric Izoard <cedric.izoard@ceva-dsp.com>

diff --git a/src/common/dpp.c b/src/common/dpp.c
index 63189c1697e95ecc86f165ff38185a0e597a0818..1fd074f056270f9e65647efe2481d122bb0d0f5e 100644 (file)
--- a/src/common/dpp.c
+++ b/src/common/dpp.c
@@ -8,8 +8,6 @@
  */
 
 #include "utils/includes.h"
-#include <openssl/evp.h>
-#include <openssl/x509.h>
 
 #include "utils/common.h"
 #include "utils/base64.h"

diff --git a/src/common/dpp_crypto.c b/src/common/dpp_crypto.c
index fa8b240c2085693f1850b071762fd4a3e9264c73..da59730eb7b79f4892ae46ddbb0e217c67cece31 100644 (file)
--- a/src/common/dpp_crypto.c
+++ b/src/common/dpp_crypto.c
@@ -8,10 +8,6 @@
  */
 
 #include "utils/includes.h"
-#include <openssl/err.h>
-#include <openssl/asn1.h>
-#include <openssl/asn1t.h>
-#include <openssl/pem.h>
 
 #include "utils/common.h"
 #include "utils/base64.h"
@@ -295,93 +291,12 @@ struct crypto_ec_key * dpp_set_keypair(const struct dpp_curve_params **curve,
 }
 
 
-typedef struct {
-       /* AlgorithmIdentifier ecPublicKey with optional parameters present
-        * as an OID identifying the curve */
-       X509_ALGOR *alg;
-       /* Compressed format public key per ANSI X9.63 */
-       ASN1_BIT_STRING *pub_key;
-} DPP_BOOTSTRAPPING_KEY;
-
-ASN1_SEQUENCE(DPP_BOOTSTRAPPING_KEY) = {
-       ASN1_SIMPLE(DPP_BOOTSTRAPPING_KEY, alg, X509_ALGOR),
-       ASN1_SIMPLE(DPP_BOOTSTRAPPING_KEY, pub_key, ASN1_BIT_STRING)
-} ASN1_SEQUENCE_END(DPP_BOOTSTRAPPING_KEY);
-
-IMPLEMENT_ASN1_FUNCTIONS(DPP_BOOTSTRAPPING_KEY);
-
-
-static struct wpabuf * dpp_bootstrap_key_der(struct crypto_ec_key *key)
-{
-       unsigned char *der = NULL;
-       int der_len;
-       const EC_KEY *eckey;
-       struct wpabuf *ret = NULL;
-       size_t len;
-       const EC_GROUP *group;
-       const EC_POINT *point;
-       BN_CTX *ctx;
-       DPP_BOOTSTRAPPING_KEY *bootstrap = NULL;
-       int nid;
-
-       ctx = BN_CTX_new();
-       eckey = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) key);
-       if (!ctx || !eckey)
-               goto fail;
-
-       group = EC_KEY_get0_group(eckey);
-       point = EC_KEY_get0_public_key(eckey);
-       if (!group || !point)
-               goto fail;
-       nid = EC_GROUP_get_curve_name(group);
-
-       bootstrap = DPP_BOOTSTRAPPING_KEY_new();
-       if (!bootstrap ||
-           X509_ALGOR_set0(bootstrap->alg, OBJ_nid2obj(EVP_PKEY_EC),
-                           V_ASN1_OBJECT, (void *) OBJ_nid2obj(nid)) != 1)
-               goto fail;
-
-       len = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED,
-                                NULL, 0, ctx);
-       if (len == 0)
-               goto fail;
-
-       der = OPENSSL_malloc(len);
-       if (!der)
-               goto fail;
-       len = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED,
-                                der, len, ctx);
-
-       OPENSSL_free(bootstrap->pub_key->data);
-       bootstrap->pub_key->data = der;
-       der = NULL;
-       bootstrap->pub_key->length = len;
-       /* No unused bits */
-       bootstrap->pub_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
-       bootstrap->pub_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
-
-       der_len = i2d_DPP_BOOTSTRAPPING_KEY(bootstrap, &der);
-       if (der_len <= 0) {
-               wpa_printf(MSG_ERROR,
-                          "DDP: Failed to build DER encoded public key");
-               goto fail;
-       }
-
-       ret = wpabuf_alloc_copy(der, der_len);
-fail:
-       DPP_BOOTSTRAPPING_KEY_free(bootstrap);
-       OPENSSL_free(der);
-       BN_CTX_free(ctx);
-       return ret;
-}
-
-
 int dpp_bootstrap_key_hash(struct dpp_bootstrap_info *bi)
 {
        struct wpabuf *der;
        int res;
 
-       der = dpp_bootstrap_key_der(bi->pubkey);
+       der = crypto_ec_key_get_subject_public_key(bi->pubkey);
        if (!der)
                return -1;
        wpa_hexdump_buf(MSG_DEBUG, "DPP: Compressed public key (DER)",
@@ -416,7 +331,7 @@ int dpp_keygen(struct dpp_bootstrap_info *bi, const char *curve,
                goto fail;
        bi->own = 1;
 
-       der = dpp_bootstrap_key_der(bi->pubkey);
+       der = crypto_ec_key_get_subject_public_key(bi->pubkey);
        if (!der)
                goto fail;
        wpa_hexdump_buf(MSG_DEBUG, "DPP: Compressed public key (DER)",

diff --git a/src/crypto/crypto_openssl.c b/src/crypto/crypto_openssl.c
index 138ab9aedf07747eba9880a5df1e2ed85732a8f7..98b93d9a7829c59a3fb6d7f2803162590da2a20b 100644 (file)
--- a/src/crypto/crypto_openssl.c
+++ b/src/crypto/crypto_openssl.c
@@ -2501,12 +2501,105 @@ void crypto_ec_key_deinit(struct crypto_ec_key *key)
 }
 
 
+#ifdef OPENSSL_IS_BORINGSSL
+
+/* BoringSSL version of i2d_PUBKEY() always outputs public EC key using
+ * uncompressed form so define a custom function to export EC pubkey using
+ * the compressed format that is explicitly required for some protocols. */
+
+#include <openssl/asn1.h>
+#include <openssl/asn1t.h>
+
+typedef struct {
+       /* AlgorithmIdentifier ecPublicKey with optional parameters present
+        * as an OID identifying the curve */
+       X509_ALGOR *alg;
+       /* Compressed format public key per ANSI X9.63 */
+       ASN1_BIT_STRING *pub_key;
+} EC_COMP_PUBKEY;
+
+ASN1_SEQUENCE(EC_COMP_PUBKEY) = {
+       ASN1_SIMPLE(EC_COMP_PUBKEY, alg, X509_ALGOR),
+       ASN1_SIMPLE(EC_COMP_PUBKEY, pub_key, ASN1_BIT_STRING)
+} ASN1_SEQUENCE_END(EC_COMP_PUBKEY);
+
+IMPLEMENT_ASN1_FUNCTIONS(EC_COMP_PUBKEY);
+
+#endif /* OPENSSL_IS_BORINGSSL */
+
+
 struct wpabuf * crypto_ec_key_get_subject_public_key(struct crypto_ec_key *key)
 {
+#ifdef OPENSSL_IS_BORINGSSL
+       unsigned char *der = NULL;
+       int der_len;
+       const EC_KEY *eckey;
+       struct wpabuf *ret = NULL;
+       size_t len;
+       const EC_GROUP *group;
+       const EC_POINT *point;
+       BN_CTX *ctx;
+       EC_COMP_PUBKEY *pubkey = NULL;
+       int nid;
+
+       ctx = BN_CTX_new();
+       eckey = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) key);
+       if (!ctx || !eckey)
+               goto fail;
+
+       group = EC_KEY_get0_group(eckey);
+       point = EC_KEY_get0_public_key(eckey);
+       if (!group || !point)
+               goto fail;
+       nid = EC_GROUP_get_curve_name(group);
+
+       pubkey = EC_COMP_PUBKEY_new();
+       if (!pubkey ||
+           X509_ALGOR_set0(pubkey->alg, OBJ_nid2obj(EVP_PKEY_EC),
+                           V_ASN1_OBJECT, (void *) OBJ_nid2obj(nid)) != 1)
+               goto fail;
+
+       len = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED,
+                                NULL, 0, ctx);
+       if (len == 0)
+               goto fail;
+
+       der = OPENSSL_malloc(len);
+       if (!der)
+               goto fail;
+       len = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED,
+                                der, len, ctx);
+
+       OPENSSL_free(pubkey->pub_key->data);
+       pubkey->pub_key->data = der;
+       der = NULL;
+       pubkey->pub_key->length = len;
+       /* No unused bits */
+       pubkey->pub_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
+       pubkey->pub_key->flags |= ASN1_STRING_FLAG_BITS_LEFT;
+
+       der_len = i2d_EC_COMP_PUBKEY(pubkey, &der);
+       if (der_len <= 0) {
+               wpa_printf(MSG_ERROR,
+                          "BoringSSL: Failed to build DER encoded public key");
+               goto fail;
+       }
+
+       ret = wpabuf_alloc_copy(der, der_len);
+fail:
+       EC_COMP_PUBKEY_free(pubkey);
+       OPENSSL_free(der);
+       BN_CTX_free(ctx);
+       return ret;
+#else /* OPENSSL_IS_BORINGSSL */
        unsigned char *der = NULL;
        int der_len;
        struct wpabuf *buf;
 
+       /* For now, all users expect COMPRESSED form */
+       EC_KEY_set_conv_form(EVP_PKEY_get0_EC_KEY((EVP_PKEY *) key),
+                            POINT_CONVERSION_COMPRESSED);
+
        der_len = i2d_PUBKEY((EVP_PKEY *) key, &der);
        if (der_len <= 0) {
                wpa_printf(MSG_INFO, "OpenSSL: i2d_PUBKEY() failed: %s",
@@ -2517,6 +2610,7 @@ struct wpabuf * crypto_ec_key_get_subject_public_key(struct crypto_ec_key *key)
        buf = wpabuf_alloc_copy(der, der_len);
        OPENSSL_free(der);
        return buf;
+#endif /* OPENSSL_IS_BORINGSSL */
 }
 
 

diff --git a/tests/hwsim/test_dpp.py b/tests/hwsim/test_dpp.py
index 558f882cd8d07d9951ff21ee93a567b20cbb546c..0579b67f33e946cf2de904671105099e7559a6ad 100644 (file)
--- a/tests/hwsim/test_dpp.py
+++ b/tests/hwsim/test_dpp.py
@@ -214,7 +214,8 @@ def test_dpp_qr_code_keygen_fail(dev, apdev):
     """DPP QR Code and keygen failure"""
     check_dpp_capab(dev[0])
 
-    with alloc_fail(dev[0], 1, "dpp_bootstrap_key_der;dpp_keygen"):
+    with alloc_fail(dev[0], 1,
+                    "crypto_ec_key_get_subject_public_key;dpp_keygen"):
         if "FAIL" not in dev[0].request("DPP_BOOTSTRAP_GEN type=qrcode"):
             raise Exception("Failure not reported")