+
+/* Example of extended certificate handling. Where the standard support
+ * of one certificate per algorithm is not sufficient an application
+ * can decide which certificate(s) to use at runtime based on whatever
+ * criteria it deems appropriate.
+ */
+
+/* Linked list of certificates, keys and chains */
+struct ssl_excert_st
+ {
+ int certform;
+ const char *certfile;
+ int keyform;
+ const char *keyfile;
+ const char *chainfile;
+ X509 *cert;
+ EVP_PKEY *key;
+ STACK_OF(X509) *chain;
+ struct ssl_excert_st *next, *prev;
+ };
+
+/* Very basic selection callback: just use any certificate chain
+ * reported as valid. More sophisticated could prioritise according
+ * to local policy.
+ */
+static int set_cert_cb(SSL *ssl, void *arg)
+ {
+ SSL_EXCERT *exc = arg;
+ SSL_certs_clear(ssl);
+
+ if (!exc)
+ return 1;
+
+ /* Go to end of list and traverse backwards since we prepend
+ * newer entries this retains the original order.
+ */
+ while (exc->next)
+ exc = exc->next;
+
+ while(exc)
+ {
+ if (SSL_check_chain(ssl, exc->cert, exc->key, exc->chain))
+ {
+ SSL_use_certificate(ssl, exc->cert);
+ SSL_use_PrivateKey(ssl, exc->key);
+ if (exc->chain)
+ SSL_set1_chain(ssl, exc->chain);
+ }
+ exc = exc->prev;
+ }
+ return 1;
+ }
+
+void ssl_ctx_set_excert(SSL_CTX *ctx, SSL_EXCERT *exc)
+ {
+ SSL_CTX_set_cert_cb(ctx, set_cert_cb, exc);
+ }
+
+static int ssl_excert_prepend(SSL_EXCERT **pexc)
+ {
+ SSL_EXCERT *exc;
+ exc = OPENSSL_malloc(sizeof(SSL_EXCERT));
+ if (!exc)
+ return 0;
+ exc->certfile = NULL;
+ exc->keyfile = NULL;
+ exc->chainfile = NULL;
+ exc->cert = NULL;
+ exc->key = NULL;
+ exc->chain = NULL;
+ exc->prev = NULL;
+
+ exc->next = *pexc;
+ *pexc = exc;
+
+ if (exc->next)
+ {
+ exc->certform = exc->next->certform;
+ exc->keyform = exc->next->keyform;
+ exc->next->prev = exc;
+ }
+ else
+ {
+ exc->certform = FORMAT_PEM;
+ exc->keyform = FORMAT_PEM;
+ }
+ return 1;
+
+ }
+
+void ssl_excert_free(SSL_EXCERT *exc)
+ {
+ SSL_EXCERT *curr;
+ while (exc)
+ {
+ if (exc->cert)
+ X509_free(exc->cert);
+ if (exc->key)
+ EVP_PKEY_free(exc->key);
+ if (exc->chain)
+ sk_X509_pop_free(exc->chain, X509_free);
+ curr = exc;
+ exc = exc->next;
+ OPENSSL_free(curr);
+ }
+ }
+
+int load_excert(SSL_EXCERT **pexc, BIO *err)
+ {
+ SSL_EXCERT *exc = *pexc;
+ if (!exc)
+ return 1;
+ /* If nothing in list, free and set to NULL */
+ if (!exc->certfile && !exc->next)
+ {
+ ssl_excert_free(exc);
+ *pexc = NULL;
+ return 1;
+ }
+ for(; exc; exc=exc->next)
+ {
+ if (!exc->certfile)
+ {
+ BIO_printf(err, "Missing filename\n");
+ return 0;
+ }
+ exc->cert = load_cert(err, exc->certfile, exc->certform,
+ NULL, NULL, "Server Certificate");
+ if (!exc->cert)
+ return 0;
+ if (exc->keyfile)
+ exc->keyfile = exc->certfile;
+ exc->key = load_key(err, exc->certfile, exc->certform, 0,
+ NULL, NULL, "Server Certificate");
+ if (!exc->key)
+ return 0;
+ if (exc->chainfile)
+ {
+ exc->chain = load_certs(err,
+ exc->chainfile, FORMAT_PEM,
+ NULL, NULL,
+ "Server Chain");
+ if (!exc->chainfile)
+ return 0;
+ }
+ }
+ return 1;
+ }
+
+
+int args_excert(char ***pargs, int *pargc,
+ int *badarg, BIO *err, SSL_EXCERT **pexc)
+ {
+ char *arg = **pargs, *argn = (*pargs)[1];
+ SSL_EXCERT *exc = *pexc;
+ if (!exc)
+ {
+ if (ssl_excert_prepend(&exc))
+ *pexc = exc;
+ else
+ {
+ BIO_printf(err, "Error initialising xcert\n");
+ *badarg = 1;
+ goto err;
+ }
+ }
+ if (strcmp(arg, "-xcert") == 0)
+ {
+ if (!argn)
+ {
+ *badarg = 1;
+ return 1;
+ }
+ if (exc->certfile && !ssl_excert_prepend(&exc))
+ {
+ BIO_printf(err, "Error adding xcert\n");
+ *badarg = 1;
+ goto err;
+ }
+ exc->certfile = argn;
+ }
+ else if (strcmp(arg,"-xkey") == 0)
+ {
+ if (!argn)
+ {
+ *badarg = 1;
+ return 1;
+ }
+ if (exc->keyfile)
+ {
+ BIO_printf(err, "Key already specified\n");
+ *badarg = 1;
+ return 1;
+ }
+ exc->keyfile = argn;
+ }
+ else if (strcmp(arg,"-xchain") == 0)
+ {
+ if (!argn)
+ {
+ *badarg = 1;
+ return 1;
+ }
+ if (exc->chainfile)
+ {
+ BIO_printf(err, "Chain already specified\n");
+ *badarg = 1;
+ return 1;
+ }
+ exc->chainfile = argn;
+ }
+ else if (strcmp(arg,"-xcertform") == 0)
+ {
+ if (!argn)
+ {
+ *badarg = 1;
+ goto err;
+ }
+ exc->certform = str2fmt(argn);
+ }
+ else if (strcmp(arg,"-xkeyform") == 0)
+ {
+ if (!argn)
+ {
+ *badarg = 1;
+ goto err;
+ }
+ exc->keyform = str2fmt(argn);
+ }
+ else
+ return 0;
+
+ (*pargs) += 2;
+
+ if (pargc)
+ *pargc -= 2;
+
+ *pexc = exc;
+
+ return 1;
+
+ err:
+ ERR_print_errors(err);
+ ssl_excert_free(exc);
+ *pexc = NULL;
+ return 1;
+ }
+
projects / openssl.git / blobdiff