Fix configuration of TLSv1.3 ciphersuites

Configuration of TLSv1.3 ciphersuites wasn't working in some cases.

Fixes #5740

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5855)

1 files changed, 128 insertions, 8 deletions

diff --git a/ssl/ssl_ciph.c b/ssl/ssl_ciph.c
index be728dfbe8..9011e42fa8 100644
--- a/ssl/ssl_ciph.c
+++ b/ssl/ssl_ciph.c
@@ -15,6 +15,7 @@
 #include <openssl/comp.h>
 #include <openssl/engine.h>
 #include <openssl/crypto.h>
+#include <openssl/conf.h>
 #include "internal/nelem.h"
 #include "ssl_locl.h"
 #include "internal/thread_once.h"
@@ -1274,6 +1275,131 @@ static int check_suiteb_cipher_list(const SSL_METHOD *meth, CERT *c,
 }
 #endif
 
+static int ciphersuite_cb(const char *elem, int len, void *arg)
+{
+    STACK_OF(SSL_CIPHER) *ciphersuites = (STACK_OF(SSL_CIPHER) *)arg;
+    const SSL_CIPHER *cipher;
+    /* Arbitrary sized temp buffer for the cipher name. Should be big enough */
+    char name[80];
+
+    if (len > (int)(sizeof(name) - 1)) {
+        SSLerr(SSL_F_CIPHERSUITE_CB, SSL_R_NO_CIPHER_MATCH);
+        return 0;
+    }
+
+    memcpy(name, elem, len);
+    name[len] = '\0';
+
+    cipher = ssl3_get_cipher_by_std_name(name);
+    if (cipher == NULL) {
+        SSLerr(SSL_F_CIPHERSUITE_CB, SSL_R_NO_CIPHER_MATCH);
+        return 0;
+    }
+
+    if (!sk_SSL_CIPHER_push(ciphersuites, cipher)) {
+        SSLerr(SSL_F_CIPHERSUITE_CB, ERR_R_INTERNAL_ERROR);
+        return 0;
+    }
+
+    return 1;
+}
+
+int set_ciphersuites(STACK_OF(SSL_CIPHER) **currciphers, const char *str)
+{
+    STACK_OF(SSL_CIPHER) *newciphers = sk_SSL_CIPHER_new_null();
+
+    if (newciphers == NULL)
+        return 0;
+
+    /* Parse the list. We explicitly allow an empty list */
+    if (*str != '\0'
+            && !CONF_parse_list(str, ':', 1, ciphersuite_cb, newciphers)) {
+        sk_SSL_CIPHER_free(newciphers);
+        return 0;
+    }
+    sk_SSL_CIPHER_free(*currciphers);
+    *currciphers = newciphers;
+
+    return 1;
+}
+
+static int update_cipher_list_by_id(STACK_OF(SSL_CIPHER) **cipher_list_by_id,
+                                    STACK_OF(SSL_CIPHER) *cipherstack)
+{
+    STACK_OF(SSL_CIPHER) *tmp_cipher_list = sk_SSL_CIPHER_dup(cipherstack);
+
+    if (tmp_cipher_list == NULL) {
+        return 0;
+    }
+
+    sk_SSL_CIPHER_free(*cipher_list_by_id);
+    *cipher_list_by_id = tmp_cipher_list;
+
+    (void)sk_SSL_CIPHER_set_cmp_func(*cipher_list_by_id, ssl_cipher_ptr_id_cmp);
+    sk_SSL_CIPHER_sort(*cipher_list_by_id);
+
+    return 1;
+}
+
+static int update_cipher_list(STACK_OF(SSL_CIPHER) **cipher_list,
+                              STACK_OF(SSL_CIPHER) **cipher_list_by_id,
+                              STACK_OF(SSL_CIPHER) *tls13_ciphersuites)
+{
+    int i;
+    STACK_OF(SSL_CIPHER) *tmp_cipher_list = sk_SSL_CIPHER_dup(*cipher_list);
+
+    if (tmp_cipher_list == NULL)
+        return 0;
+
+    /*
+     * Delete any existing TLSv1.3 ciphersuites. These are always first in the
+     * list.
+     */
+    while (sk_SSL_CIPHER_num(tmp_cipher_list) > 0
+           && sk_SSL_CIPHER_value(tmp_cipher_list, 0)->min_tls
+              == TLS1_3_VERSION)
+        sk_SSL_CIPHER_delete(tmp_cipher_list, 0);
+
+    /* Insert the new TLSv1.3 ciphersuites */
+    for (i = 0; i < sk_SSL_CIPHER_num(tls13_ciphersuites); i++)
+        sk_SSL_CIPHER_insert(tmp_cipher_list,
+                             sk_SSL_CIPHER_value(tls13_ciphersuites, i), i);
+
+    if (!update_cipher_list_by_id(cipher_list_by_id, tmp_cipher_list))
+        return 0;
+
+    sk_SSL_CIPHER_free(*cipher_list);
+    *cipher_list = tmp_cipher_list;
+
+    return 1;
+}
+
+int SSL_CTX_set_ciphersuites(SSL_CTX *ctx, const char *str)
+{
+    int ret = set_ciphersuites(&(ctx->tls13_ciphersuites), str);
+
+    if (ret && ctx->cipher_list != NULL) {
+        /* We already have a cipher_list, so we need to update it */
+        return update_cipher_list(&ctx->cipher_list, &ctx->cipher_list_by_id,
+                                  ctx->tls13_ciphersuites);
+    }
+
+    return ret;
+}
+
+int SSL_set_ciphersuites(SSL *s, const char *str)
+{
+    int ret = set_ciphersuites(&(s->tls13_ciphersuites), str);
+
+    if (ret && s->cipher_list != NULL) {
+        /* We already have a cipher_list, so we need to update it */
+        return update_cipher_list(&s->cipher_list, &s->cipher_list_by_id,
+                                  s->tls13_ciphersuites);
+    }
+
+    return ret;
+}
+
 STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method,
                                              STACK_OF(SSL_CIPHER) *tls13_ciphersuites,
                                              STACK_OF(SSL_CIPHER) **cipher_list,
@@ -1283,7 +1409,7 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method,
 {
     int ok, num_of_ciphers, num_of_alias_max, num_of_group_aliases, i;
     uint32_t disabled_mkey, disabled_auth, disabled_enc, disabled_mac;
-    STACK_OF(SSL_CIPHER) *cipherstack, *tmp_cipher_list;
+    STACK_OF(SSL_CIPHER) *cipherstack;
     const char *rule_p;
     CIPHER_ORDER *co_list = NULL, *head = NULL, *tail = NULL, *curr;
     const SSL_CIPHER **ca_list = NULL;
@@ -1498,19 +1624,13 @@ STACK_OF(SSL_CIPHER) *ssl_create_cipher_list(const SSL_METHOD *ssl_method,
     }
     OPENSSL_free(co_list);      /* Not needed any longer */
 
-    tmp_cipher_list = sk_SSL_CIPHER_dup(cipherstack);
-    if (tmp_cipher_list == NULL) {
+    if (!update_cipher_list_by_id(cipher_list_by_id, cipherstack)) {
         sk_SSL_CIPHER_free(cipherstack);
         return NULL;
     }
     sk_SSL_CIPHER_free(*cipher_list);
     *cipher_list = cipherstack;
-    if (*cipher_list_by_id != NULL)
-        sk_SSL_CIPHER_free(*cipher_list_by_id);
-    *cipher_list_by_id = tmp_cipher_list;
-    (void)sk_SSL_CIPHER_set_cmp_func(*cipher_list_by_id, ssl_cipher_ptr_id_cmp);
 
-    sk_SSL_CIPHER_sort(*cipher_list_by_id);
     return cipherstack;
 }