+
+static int generate_private_pkey(struct asymmetric_key *priv,
+ const BIGNUM *n, const BIGNUM *e, const BIGNUM *d,
+ const BIGNUM *p, const BIGNUM *q)
+{
+ const BIGNUM *bignums[] = {n, e, d, p, q};
+ const char *strings[] = {"n", "e", "d", "p", "q"};
+ int ret, bytes[ARRAY_SIZE(bignums)];
+ unsigned char *bufs[ARRAY_SIZE(bignums)];
+ OSSL_PARAM params[ARRAY_SIZE(bignums) + 1];
+ /*
+ * Convert bignums to buffers for OSSL_PARAM_construct_BN() and init
+ * params[].
+ */
+ for (int i = 0; i < ARRAY_SIZE(bignums); i++) {
+ bytes[i] = BN_num_bytes(bignums[i]);
+ PARA_DEBUG_LOG("%s: %d bits\n", strings[i], bytes[i] * 8);
+ bufs[i] = alloc(bytes[i]);
+ assert(BN_bn2nativepad(bignums[i], bufs[i], bytes[i]) > 0);
+ params[i] = OSSL_PARAM_construct_BN(strings[i], bufs[i],
+ bytes[i]);
+ }
+ params[ARRAY_SIZE(bignums)] = OSSL_PARAM_construct_end();
+ /* Transfer buffers to openssl to create the pkey from it */
+ priv->ctx = EVP_PKEY_CTX_new_from_name(NULL, "RSA", NULL);
+ assert(priv->ctx);
+ assert(EVP_PKEY_fromdata_init(priv->ctx) > 0);
+ ret = EVP_PKEY_fromdata(priv->ctx, &priv->pkey,
+ EVP_PKEY_KEYPAIR, params);
+ for (int i = 0; i < ARRAY_SIZE(bignums); i++)
+ free(bufs[i]);
+ if (ret <= 0) {
+ EVP_PKEY_CTX_free(priv->ctx);
+ return openssl_perror("EVP_PKEY_fromdata()");
+ }
+ assert(priv->pkey);
+ return BN_num_bytes(n) * 8;
+}
+