DPP: Move PKEX Commit-Reveal Response building to a helper function

This cleans up dpp_pkex_rx_commit_reveal_req() a bit and makes it easier
to add protocol testing functionality to PKEX exchange similarly to the
previously added DPP Authentication case.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

diff --git a/src/common/dpp.c b/src/common/dpp.c
index ca4e6bf36e20a0576703449cdabc2d53dc2a20b3..5aededd038803bf3b34e5e2aa3b71a8da097e2d2 100644 (file)
--- a/src/common/dpp.c
+++ b/src/common/dpp.c
@@ -6155,6 +6155,80 @@ fail:
 }
 
 
+static struct wpabuf *
+dpp_pkex_build_commit_reveal_resp(struct dpp_pkex *pkex,
+                                 const struct wpabuf *B_pub, const u8 *v)
+{
+       const struct dpp_curve_params *curve = pkex->own_bi->curve;
+       struct wpabuf *msg = NULL;
+       const u8 *addr[2];
+       size_t len[2];
+       u8 octet;
+       u8 *wrapped;
+       struct wpabuf *clear = NULL;
+       size_t clear_len, attr_len;
+
+       /* {B, v [bootstrapping info]}z */
+       clear_len = 4 + 2 * curve->prime_len + 4 + curve->hash_len;
+       clear = wpabuf_alloc(clear_len);
+       attr_len = 4 + clear_len + AES_BLOCK_SIZE;
+#ifdef CONFIG_TESTING_OPTIONS
+       if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_RESP)
+               attr_len += 4;
+#endif /* CONFIG_TESTING_OPTIONS */
+       msg = dpp_alloc_msg(DPP_PA_PKEX_COMMIT_REVEAL_RESP, attr_len);
+       if (!clear || !msg)
+               goto fail;
+
+       /* A in Bootstrap Key attribute */
+       wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY);
+       wpabuf_put_le16(clear, wpabuf_len(B_pub));
+       wpabuf_put_buf(clear, B_pub);
+
+       /* v in R-Auth tag attribute */
+       wpabuf_put_le16(clear, DPP_ATTR_R_AUTH_TAG);
+       wpabuf_put_le16(clear, curve->hash_len);
+       wpabuf_put_data(clear, v, curve->hash_len);
+
+       addr[0] = wpabuf_head_u8(msg) + 2;
+       len[0] = DPP_HDR_LEN;
+       octet = 1;
+       addr[1] = &octet;
+       len[1] = sizeof(octet);
+       wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
+       wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
+
+       wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
+       wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
+       wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
+
+       wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear);
+       if (aes_siv_encrypt(pkex->z, curve->hash_len,
+                           wpabuf_head(clear), wpabuf_len(clear),
+                           2, addr, len, wrapped) < 0)
+               goto fail;
+       wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
+                   wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE);
+
+#ifdef CONFIG_TESTING_OPTIONS
+       if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_RESP) {
+               wpa_printf(MSG_INFO, "DPP: TESTING - attr after Wrapped Data");
+               wpabuf_put_le16(msg, DPP_ATTR_TESTING);
+               wpabuf_put_le16(msg, 0);
+       }
+#endif /* CONFIG_TESTING_OPTIONS */
+
+out:
+       wpabuf_free(clear);
+       return msg;
+
+fail:
+       wpabuf_free(msg);
+       msg = NULL;
+       goto out;
+}
+
+
 struct wpabuf * dpp_pkex_rx_commit_reveal_req(struct dpp_pkex *pkex,
                                              const u8 *hdr,
                                              const u8 *buf, size_t buflen)
@@ -6174,9 +6248,6 @@ struct wpabuf * dpp_pkex_rx_commit_reveal_req(struct dpp_pkex *pkex,
        struct wpabuf *msg = NULL, *A_pub = NULL, *X_pub = NULL, *Y_pub = NULL;
        struct wpabuf *B_pub = NULL;
        u8 u[DPP_MAX_HASH_LEN], v[DPP_MAX_HASH_LEN];
-       size_t clear_len, attr_len;
-       struct wpabuf *clear = NULL;
-       u8 *wrapped;
        int res;
 
        /* K = y * X' */
@@ -6340,55 +6411,10 @@ struct wpabuf * dpp_pkex_rx_commit_reveal_req(struct dpp_pkex *pkex,
                goto fail;
        wpa_hexdump(MSG_DEBUG, "DPP: v", v, curve->hash_len);
 
-       /* {B, v [bootstrapping info]}z */
-       clear_len = 4 + 2 * curve->prime_len + 4 + curve->hash_len;
-       clear = wpabuf_alloc(clear_len);
-       attr_len = 4 + clear_len + AES_BLOCK_SIZE;
-#ifdef CONFIG_TESTING_OPTIONS
-       if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_RESP)
-               attr_len += 4;
-#endif /* CONFIG_TESTING_OPTIONS */
-       msg = dpp_alloc_msg(DPP_PA_PKEX_COMMIT_REVEAL_RESP, attr_len);
-       if (!clear || !msg)
-               goto fail;
-
-       /* A in Bootstrap Key attribute */
-       wpabuf_put_le16(clear, DPP_ATTR_BOOTSTRAP_KEY);
-       wpabuf_put_le16(clear, wpabuf_len(B_pub));
-       wpabuf_put_buf(clear, B_pub);
-
-       /* v in R-Auth tag attribute */
-       wpabuf_put_le16(clear, DPP_ATTR_R_AUTH_TAG);
-       wpabuf_put_le16(clear, curve->hash_len);
-       wpabuf_put_data(clear, v, curve->hash_len);
-
-       addr[0] = wpabuf_head_u8(msg) + 2;
-       len[0] = DPP_HDR_LEN;
-       octet = 1;
-       addr[1] = &octet;
-       len[1] = sizeof(octet);
-       wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[0]", addr[0], len[0]);
-       wpa_hexdump(MSG_DEBUG, "DDP: AES-SIV AD[1]", addr[1], len[1]);
-
-       wpabuf_put_le16(msg, DPP_ATTR_WRAPPED_DATA);
-       wpabuf_put_le16(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
-       wrapped = wpabuf_put(msg, wpabuf_len(clear) + AES_BLOCK_SIZE);
-
-       wpa_hexdump_buf(MSG_DEBUG, "DPP: AES-SIV cleartext", clear);
-       if (aes_siv_encrypt(pkex->z, curve->hash_len,
-                           wpabuf_head(clear), wpabuf_len(clear),
-                           2, addr, len, wrapped) < 0)
+       msg = dpp_pkex_build_commit_reveal_resp(pkex, B_pub, v);
+       if (!msg)
                goto fail;
-       wpa_hexdump(MSG_DEBUG, "DPP: AES-SIV ciphertext",
-                   wrapped, wpabuf_len(clear) + AES_BLOCK_SIZE);
 
-#ifdef CONFIG_TESTING_OPTIONS
-       if (dpp_test == DPP_TEST_AFTER_WRAPPED_DATA_PKEX_CR_RESP) {
-               wpa_printf(MSG_INFO, "DPP: TESTING - attr after Wrapped Data");
-               wpabuf_put_le16(msg, DPP_ATTR_TESTING);
-               wpabuf_put_le16(msg, 0);
-       }
-#endif /* CONFIG_TESTING_OPTIONS */
 out:
        EVP_PKEY_CTX_free(ctx);
        os_free(unwrapped);
@@ -6396,11 +6422,10 @@ out:
        wpabuf_free(B_pub);
        wpabuf_free(X_pub);
        wpabuf_free(Y_pub);
-       wpabuf_free(clear);
        return msg;
 fail:
-       wpabuf_free(msg);
-       msg = NULL;
+       wpa_printf(MSG_DEBUG,
+                  "DPP: PKEX Commit-Reveal Request processing failed");
        goto out;
 }