+ return 1;
+}
+
+int dh_buf2key(DH *dh, const unsigned char *buf, size_t len)
+{
+ int err_reason = DH_R_BN_ERROR;
+ BIGNUM *pubkey = NULL;
+ const BIGNUM *p;
+ size_t p_size;
+
+ if ((pubkey = BN_bin2bn(buf, len, NULL)) == NULL)
+ goto err;
+ DH_get0_pqg(dh, &p, NULL, NULL);
+ if (p == NULL || (p_size = BN_num_bytes(p)) == 0) {
+ err_reason = DH_R_NO_PARAMETERS_SET;
+ goto err;
+ }
+ /*
+ * As per Section 4.2.8.1 of RFC 8446 fail if DHE's
+ * public key is of size not equal to size of p
+ */
+ if (BN_is_zero(pubkey) || p_size != len) {
+ err_reason = DH_R_INVALID_PUBKEY;
+ goto err;
+ }
+ if (DH_set0_key(dh, pubkey, NULL) != 1)
+ goto err;
+ return 1;
+err:
+ DHerr(DH_F_DH_BUF2KEY, err_reason);
+ BN_free(pubkey);
+ return 0;
+}
+
+size_t dh_key2buf(const DH *dh, unsigned char **pbuf_out)
+{
+ const BIGNUM *pubkey;
+ unsigned char *pbuf;
+ const BIGNUM *p;
+ int p_size;
+
+ DH_get0_pqg(dh, &p, NULL, NULL);
+ DH_get0_key(dh, &pubkey, NULL);
+ if (p == NULL || pubkey == NULL
+ || (p_size = BN_num_bytes(p)) == 0
+ || BN_num_bytes(pubkey) == 0) {
+ DHerr(DH_F_DH_KEY2BUF, DH_R_INVALID_PUBKEY);
+ return 0;
+ }
+ if ((pbuf = OPENSSL_malloc(p_size)) == NULL) {
+ DHerr(DH_F_DH_KEY2BUF, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+ /*
+ * As per Section 4.2.8.1 of RFC 8446 left pad public
+ * key with zeros to the size of p
+ */
+ if (BN_bn2binpad(pubkey, pbuf, p_size) < 0) {
+ OPENSSL_free(pbuf);
+ DHerr(DH_F_DH_KEY2BUF, DH_R_BN_ERROR);
+ return 0;
+ }
+ *pbuf_out = pbuf;
+ return p_size;