1 files changed, 258 insertions, 165 deletions

diff --git a/thirdparty/mbedtls/library/ssl_cache.c b/thirdparty/mbedtls/library/ssl_cache.c
index 21e38cd86a..772cb8fdfe 100644
--- a/thirdparty/mbedtls/library/ssl_cache.c
+++ b/thirdparty/mbedtls/library/ssl_cache.c
@@ -14,10 +14,10 @@
 #if defined(MBEDTLS_SSL_CACHE_C)
 
 #include "mbedtls/platform.h"
-#include "mbedtls/error.h"
 
 #include "mbedtls/ssl_cache.h"
-#include "mbedtls/ssl_internal.h"
+#include "ssl_misc.h"
+#include "mbedtls/error.h"
 
 #include <string.h>
 
@@ -33,76 +33,73 @@ void mbedtls_ssl_cache_init(mbedtls_ssl_cache_context *cache)
 #endif
 }
 
-int mbedtls_ssl_cache_get(void *data, mbedtls_ssl_session *session)
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_cache_find_entry(mbedtls_ssl_cache_context *cache,
+                                unsigned char const *session_id,
+                                size_t session_id_len,
+                                mbedtls_ssl_cache_entry **dst)
 {
     int ret = MBEDTLS_ERR_SSL_CACHE_ENTRY_NOT_FOUND;
 #if defined(MBEDTLS_HAVE_TIME)
     mbedtls_time_t t = mbedtls_time(NULL);
 #endif
-    mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data;
-    mbedtls_ssl_cache_entry *cur, *entry;
-
-#if defined(MBEDTLS_THREADING_C)
-    if ((ret = mbedtls_mutex_lock(&cache->mutex)) != 0) {
-        return ret;
-    }
-#endif
-
-    cur = cache->chain;
-    entry = NULL;
-
-    while (cur != NULL) {
-        entry = cur;
-        cur = cur->next;
+    mbedtls_ssl_cache_entry *cur;
 
+    for (cur = cache->chain; cur != NULL; cur = cur->next) {
 #if defined(MBEDTLS_HAVE_TIME)
         if (cache->timeout != 0 &&
-            (int) (t - entry->timestamp) > cache->timeout) {
+            (int) (t - cur->timestamp) > cache->timeout) {
             continue;
         }
 #endif
 
-        if (session->id_len != entry->session.id_len ||
-            memcmp(session->id, entry->session.id,
-                   entry->session.id_len) != 0) {
+        if (session_id_len != cur->session_id_len ||
+            memcmp(session_id, cur->session_id,
+                   cur->session_id_len) != 0) {
             continue;
         }
 
-        ret = mbedtls_ssl_session_copy(session, &entry->session);
-        if (ret != 0) {
-            goto exit;
-        }
-
-#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
-        defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
-        /*
-         * Restore peer certificate (without rest of the original chain)
-         */
-        if (entry->peer_cert.p != NULL) {
-            /* `session->peer_cert` is NULL after the call to
-             * mbedtls_ssl_session_copy(), because cache entries
-             * have the `peer_cert` field set to NULL. */
-
-            if ((session->peer_cert = mbedtls_calloc(1,
-                                                     sizeof(mbedtls_x509_crt))) == NULL) {
-                ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
-                goto exit;
-            }
-
-            mbedtls_x509_crt_init(session->peer_cert);
-            if ((ret = mbedtls_x509_crt_parse(session->peer_cert, entry->peer_cert.p,
-                                              entry->peer_cert.len)) != 0) {
-                mbedtls_free(session->peer_cert);
-                session->peer_cert = NULL;
-                goto exit;
-            }
-        }
-#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+        break;
+    }
 
+    if (cur != NULL) {
+        *dst = cur;
         ret = 0;
+    }
+
+    return ret;
+}
+
+
+int mbedtls_ssl_cache_get(void *data,
+                          unsigned char const *session_id,
+                          size_t session_id_len,
+                          mbedtls_ssl_session *session)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data;
+    mbedtls_ssl_cache_entry *entry;
+
+#if defined(MBEDTLS_THREADING_C)
+    if ((ret = mbedtls_mutex_lock(&cache->mutex)) != 0) {
+        return ret;
+    }
+#endif
+
+    ret = ssl_cache_find_entry(cache, session_id, session_id_len, &entry);
+    if (ret != 0) {
         goto exit;
     }
 
+    ret = mbedtls_ssl_session_load(session,
+                                   entry->session,
+                                   entry->session_len);
+    if (ret != 0) {
+        goto exit;
+    }
+
+    ret = 0;
+
 exit:
 #if defined(MBEDTLS_THREADING_C)
     if (mbedtls_mutex_unlock(&cache->mutex) != 0) {
@@ -113,149 +110,251 @@ exit:
     return ret;
 }
 
-int mbedtls_ssl_cache_set(void *data, const mbedtls_ssl_session *session)
+/* zeroize a cache entry */
+static void ssl_cache_entry_zeroize(mbedtls_ssl_cache_entry *entry)
+{
+    if (entry == NULL) {
+        return;
+    }
+
+    /* zeroize and free session structure */
+    if (entry->session != NULL) {
+        mbedtls_zeroize_and_free(entry->session, entry->session_len);
+    }
+
+    /* zeroize the whole entry structure */
+    mbedtls_platform_zeroize(entry, sizeof(mbedtls_ssl_cache_entry));
+}
+
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_cache_pick_writing_slot(mbedtls_ssl_cache_context *cache,
+                                       unsigned char const *session_id,
+                                       size_t session_id_len,
+                                       mbedtls_ssl_cache_entry **dst)
 {
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 #if defined(MBEDTLS_HAVE_TIME)
     mbedtls_time_t t = mbedtls_time(NULL), oldest = 0;
+#endif /* MBEDTLS_HAVE_TIME */
+
     mbedtls_ssl_cache_entry *old = NULL;
-#endif
-    mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data;
-    mbedtls_ssl_cache_entry *cur, *prv;
     int count = 0;
-
-#if defined(MBEDTLS_THREADING_C)
-    if ((ret = mbedtls_mutex_lock(&cache->mutex)) != 0) {
-        return ret;
+    mbedtls_ssl_cache_entry *cur, *last;
+
+    /* Check 1: Is there already an entry with the given session ID?
+     *
+     * If yes, overwrite it.
+     *
+     * If not, `count` will hold the size of the session cache
+     * at the end of this loop, and `last` will point to the last
+     * entry, both of which will be used later. */
+
+    last = NULL;
+    for (cur = cache->chain; cur != NULL; cur = cur->next) {
+        count++;
+        if (session_id_len == cur->session_id_len &&
+            memcmp(session_id, cur->session_id, cur->session_id_len) == 0) {
+            goto found;
+        }
+        last = cur;
     }
-#endif
 
-    cur = cache->chain;
-    prv = NULL;
-
-    while (cur != NULL) {
-        count++;
+    /* Check 2: Is there an outdated entry in the cache?
+     *
+     * If so, overwrite it.
+     *
+     * If not, remember the oldest entry in `old` for later.
+     */
 
 #if defined(MBEDTLS_HAVE_TIME)
+    for (cur = cache->chain; cur != NULL; cur = cur->next) {
         if (cache->timeout != 0 &&
             (int) (t - cur->timestamp) > cache->timeout) {
-            cur->timestamp = t;
-            break; /* expired, reuse this slot, update timestamp */
+            goto found;
         }
-#endif
-
-        if (memcmp(session->id, cur->session.id, cur->session.id_len) == 0) {
-            break; /* client reconnected, keep timestamp for session id */
 
-        }
-#if defined(MBEDTLS_HAVE_TIME)
         if (oldest == 0 || cur->timestamp < oldest) {
             oldest = cur->timestamp;
             old = cur;
         }
-#endif
+    }
+#endif /* MBEDTLS_HAVE_TIME */
 
-        prv = cur;
-        cur = cur->next;
+    /* Check 3: Is there free space in the cache? */
+
+    if (count < cache->max_entries) {
+        /* Create new entry */
+        cur = mbedtls_calloc(1, sizeof(mbedtls_ssl_cache_entry));
+        if (cur == NULL) {
+            return MBEDTLS_ERR_SSL_ALLOC_FAILED;
+        }
+
+        /* Append to the end of the linked list. */
+        if (last == NULL) {
+            cache->chain = cur;
+        } else {
+            last->next = cur;
+        }
+
+        goto found;
     }
 
-    if (cur == NULL) {
+    /* Last resort: The cache is full and doesn't contain any outdated
+     * elements. In this case, we evict the oldest one, judged by timestamp
+     * (if present) or cache-order. */
+
 #if defined(MBEDTLS_HAVE_TIME)
-        /*
-         * Reuse oldest entry if max_entries reached
-         */
-        if (count >= cache->max_entries) {
-            if (old == NULL) {
-                /* This should only happen on an ill-configured cache
-                 * with max_entries == 0. */
-                ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
-                goto exit;
-            }
-
-            cur = old;
-        }
+    if (old == NULL) {
+        /* This should only happen on an ill-configured cache
+         * with max_entries == 0. */
+        return MBEDTLS_ERR_SSL_INTERNAL_ERROR;
+    }
 #else /* MBEDTLS_HAVE_TIME */
-        /*
-         * Reuse first entry in chain if max_entries reached,
-         * but move to last place
-         */
-        if (count >= cache->max_entries) {
-            if (cache->chain == NULL) {
-                ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
-                goto exit;
-            }
-
-            cur = cache->chain;
-            cache->chain = cur->next;
-            cur->next = NULL;
-            prv->next = cur;
-        }
+    /* Reuse first entry in chain, but move to last place. */
+    if (cache->chain == NULL) {
+        /* This should never happen */
+        return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    }
+
+    old = cache->chain;
+    cache->chain = old->next;
+    old->next = NULL;
+    last->next = old;
 #endif /* MBEDTLS_HAVE_TIME */
-        else {
-            /*
-             * max_entries not reached, create new entry
-             */
-            cur = mbedtls_calloc(1, sizeof(mbedtls_ssl_cache_entry));
-            if (cur == NULL) {
-                ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
-                goto exit;
-            }
-
-            if (prv == NULL) {
-                cache->chain = cur;
-            } else {
-                prv->next = cur;
-            }
-        }
+
+    /* Now `old` points to the oldest entry to be overwritten. */
+    cur = old;
+
+found:
+
+    /* If we're reusing an entry, free it first. */
+    if (cur->session != NULL) {
+        /* `ssl_cache_entry_zeroize` would break the chain,
+         * so we reuse `old` to record `next` temporarily. */
+        old = cur->next;
+        ssl_cache_entry_zeroize(cur);
+        cur->next = old;
+    }
 
 #if defined(MBEDTLS_HAVE_TIME)
-        cur->timestamp = t;
+    cur->timestamp = t;
+#endif
+
+    *dst = cur;
+    return 0;
+}
+
+int mbedtls_ssl_cache_set(void *data,
+                          unsigned char const *session_id,
+                          size_t session_id_len,
+                          const mbedtls_ssl_session *session)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data;
+    mbedtls_ssl_cache_entry *cur;
+
+    size_t session_serialized_len = 0;
+    unsigned char *session_serialized = NULL;
+
+#if defined(MBEDTLS_THREADING_C)
+    if ((ret = mbedtls_mutex_lock(&cache->mutex)) != 0) {
+        return ret;
+    }
 #endif
+
+    ret = ssl_cache_pick_writing_slot(cache,
+                                      session_id, session_id_len,
+                                      &cur);
+    if (ret != 0) {
+        goto exit;
     }
 
-#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
-    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
-    /*
-     * If we're reusing an entry, free its certificate first
-     */
-    if (cur->peer_cert.p != NULL) {
-        mbedtls_free(cur->peer_cert.p);
-        memset(&cur->peer_cert, 0, sizeof(mbedtls_x509_buf));
+    /* Check how much space we need to serialize the session
+     * and allocate a sufficiently large buffer. */
+    ret = mbedtls_ssl_session_save(session, NULL, 0, &session_serialized_len);
+    if (ret != MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL) {
+        goto exit;
+    }
+
+    session_serialized = mbedtls_calloc(1, session_serialized_len);
+    if (session_serialized == NULL) {
+        ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
+        goto exit;
     }
-#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
-
-    /* Copy the entire session; this temporarily makes a copy of the
-     * X.509 CRT structure even though we only want to store the raw CRT.
-     * This inefficiency will go away as soon as we implement on-demand
-     * parsing of CRTs, in which case there's no need for the `peer_cert`
-     * field anymore in the first place, and we're done after this call. */
-    ret = mbedtls_ssl_session_copy(&cur->session, session);
+
+    /* Now serialize the session into the allocated buffer. */
+    ret = mbedtls_ssl_session_save(session,
+                                   session_serialized,
+                                   session_serialized_len,
+                                   &session_serialized_len);
     if (ret != 0) {
         goto exit;
     }
 
-#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
-    defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
-    /* If present, free the X.509 structure and only store the raw CRT data. */
-    if (cur->session.peer_cert != NULL) {
-        cur->peer_cert.p =
-            mbedtls_calloc(1, cur->session.peer_cert->raw.len);
-        if (cur->peer_cert.p == NULL) {
-            ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
-            goto exit;
-        }
+    if (session_id_len > sizeof(cur->session_id)) {
+        ret = MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
+        goto exit;
+    }
+    cur->session_id_len = session_id_len;
+    memcpy(cur->session_id, session_id, session_id_len);
+
+    cur->session = session_serialized;
+    cur->session_len = session_serialized_len;
+    session_serialized = NULL;
 
-        memcpy(cur->peer_cert.p,
-               cur->session.peer_cert->raw.p,
-               cur->session.peer_cert->raw.len);
-        cur->peer_cert.len = session->peer_cert->raw.len;
+    ret = 0;
 
-        mbedtls_x509_crt_free(cur->session.peer_cert);
-        mbedtls_free(cur->session.peer_cert);
-        cur->session.peer_cert = NULL;
+exit:
+#if defined(MBEDTLS_THREADING_C)
+    if (mbedtls_mutex_unlock(&cache->mutex) != 0) {
+        ret = MBEDTLS_ERR_THREADING_MUTEX_ERROR;
+    }
+#endif
+
+    if (session_serialized != NULL) {
+        mbedtls_zeroize_and_free(session_serialized, session_serialized_len);
+        session_serialized = NULL;
     }
-#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 
+    return ret;
+}
+
+int mbedtls_ssl_cache_remove(void *data,
+                             unsigned char const *session_id,
+                             size_t session_id_len)
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_cache_context *cache = (mbedtls_ssl_cache_context *) data;
+    mbedtls_ssl_cache_entry *entry;
+    mbedtls_ssl_cache_entry *prev;
+
+#if defined(MBEDTLS_THREADING_C)
+    if ((ret = mbedtls_mutex_lock(&cache->mutex)) != 0) {
+        return ret;
+    }
+#endif
+
+    ret = ssl_cache_find_entry(cache, session_id, session_id_len, &entry);
+    /* No valid entry found, exit with success */
+    if (ret != 0) {
+        ret = 0;
+        goto exit;
+    }
+
+    /* Now we remove the entry from the chain */
+    if (entry == cache->chain) {
+        cache->chain = entry->next;
+        goto free;
+    }
+    for (prev = cache->chain; prev->next != NULL; prev = prev->next) {
+        if (prev->next == entry) {
+            prev->next = entry->next;
+            break;
+        }
+    }
+
+free:
+    ssl_cache_entry_zeroize(entry);
+    mbedtls_free(entry);
     ret = 0;
 
 exit:
@@ -298,13 +397,7 @@ void mbedtls_ssl_cache_free(mbedtls_ssl_cache_context *cache)
         prv = cur;
         cur = cur->next;
 
-        mbedtls_ssl_session_free(&prv->session);
-
-#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
-        defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
-        mbedtls_free(prv->peer_cert.p);
-#endif /* MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
-
+        ssl_cache_entry_zeroize(prv);
         mbedtls_free(prv);
     }