+/*
+ * protocol_from_string - converts a protocol version string to a number
+ *
+ * Returns -1 on failure or the version on success
+ */
+static int protocol_from_string(const char *value)
+{
+ struct protocol_versions {
+ const char *name;
+ int version;
+ };
+ static const struct protocol_versions versions[] = {
+ {"ssl3", SSL3_VERSION},
+ {"tls1", TLS1_VERSION},
+ {"tls1.1", TLS1_1_VERSION},
+ {"tls1.2", TLS1_2_VERSION},
+ {"dtls1", DTLS1_VERSION},
+ {"dtls1.2", DTLS1_2_VERSION}};
+ size_t i;
+ size_t n = OSSL_NELEM(versions);
+
+ for (i = 0; i < n; i++)
+ if (strcmp(versions[i].name, value) == 0)
+ return versions[i].version;
+ return -1;
+}
+
+/*
+ * set_protocol_version - Sets protocol version minimum or maximum
+ *
+ * Returns 0 on failure and 1 on success
+ */
+static int set_protocol_version(const char *version, SSL *ssl, int setting)
+{
+ if (version != NULL) {
+ int ver = protocol_from_string(version);
+ if (ver < 0) {
+ BIO_printf(bio_err, "Error parsing: %s\n", version);
+ return 0;
+ }
+ return SSL_ctrl(ssl, setting, ver, NULL);
+ }
+ return 1;
+}
+