DPP2: Add challengePassword into CSR

Derive challengePassword from bk and add it into the CSR.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

diff --git a/src/common/dpp.h b/src/common/dpp.h
index a84cdc6560243aa922f0d3df1dd9e56b7810fb94..a43b85fc2c054afaa468fe6a71c3c92966a71160 100644 (file)
--- a/src/common/dpp.h
+++ b/src/common/dpp.h
@@ -120,6 +120,7 @@ enum dpp_connector_key {
 #define DPP_MAX_NONCE_LEN 32
 #define DPP_MAX_HASH_LEN 64
 #define DPP_MAX_SHARED_SECRET_LEN 66
+#define DPP_CP_LEN 64
 
 struct dpp_curve_params {
        const char *name;

diff --git a/src/common/dpp_crypto.c b/src/common/dpp_crypto.c
index 1990b82ffdc50de03982b66336e19857f49b7fed..744f099ce8528676fcb0aa2f2487f26f039c082c 100644 (file)
--- a/src/common/dpp_crypto.c
+++ b/src/common/dpp_crypto.c
@@ -2677,6 +2677,10 @@ struct wpabuf * dpp_build_csr(struct dpp_authentication *auth)
        unsigned int hash_len = auth->curve->hash_len;
        EC_KEY *eckey;
        BIO *out = NULL;
+       u8 cp[DPP_CP_LEN];
+       char *password;
+       size_t password_len;
+       int res;
 
        /* TODO: use auth->csrattrs */
 
@@ -2701,6 +2705,26 @@ struct wpabuf * dpp_build_csr(struct dpp_authentication *auth)
        if (!req || !X509_REQ_set_pubkey(req, key))
                goto fail;
 
+       /* cp = HKDF-Expand(bk, "CSR challengePassword", 64) */
+       if (dpp_hkdf_expand(hash_len, auth->bk, hash_len,
+                           "CSR challengePassword", cp, DPP_CP_LEN) < 0)
+               goto fail;
+       wpa_hexdump_key(MSG_DEBUG,
+                       "DPP: cp = HKDF-Expand(bk, \"CSR challengePassword\", 64)",
+                       cp, DPP_CP_LEN);
+       password = base64_encode_no_lf(cp, DPP_CP_LEN, &password_len);
+       forced_memzero(cp, DPP_CP_LEN);
+       if (!password)
+               goto fail;
+
+       res = X509_REQ_add1_attr_by_NID(req, NID_pkcs9_challengePassword,
+                                       V_ASN1_UTF8STRING,
+                                       (const unsigned char *) password,
+                                       password_len);
+       bin_clear_free(password, password_len);
+       if (!res)
+               goto fail;
+
        /* TODO */
 
        /* TODO: hash func selection based on csrAttrs */