Merge tag '0.80'.

This involved a trivial merge conflict fix in terminal.c because of
the way the cherry-pick 73b41feba5 differed from its original
bdbd5f429c.

But a more significant rework was needed in windows/console.c, because
the updates to confirm_weak_* conflicted with the changes on main to
abstract out the ConsoleIO system.

ssh.h

@@ -1903,11 +1903,26 @@ void add_to_commasep(strbuf *buf, const char *data);
 void add_to_commasep_pl(strbuf *buf, ptrlen data);
 bool get_commasep_word(ptrlen *list, ptrlen *word);
 
+/* Reasons why something warned by confirm_weak_crypto_primitive might
+ * be considered weak */
+typedef enum WeakCryptoReason {
+    WCR_BELOW_THRESHOLD, /* user has told us to consider it weak */
+    WCR_TERRAPIN,        /* known vulnerability CVE-2023-48795 */
+    WCR_TERRAPIN_AVOIDABLE, /* same, but demoting ChaCha20 can avoid it */
+} WeakCryptoReason;
+
 SeatPromptResult verify_ssh_host_key(
     InteractionReadySeat iseat, Conf *conf, const char *host, int port,
     ssh_key *key, const char *keytype, char *keystr, const char *keydisp,
     char **fingerprints, int ca_count,
     void (*callback)(void *ctx, SeatPromptResult result), void *ctx);
+SeatPromptResult confirm_weak_crypto_primitive(
+    InteractionReadySeat iseat, const char *algtype, const char *algname,
+    void (*callback)(void *ctx, SeatPromptResult result), void *ctx,
+    WeakCryptoReason wcr);
+SeatPromptResult confirm_weak_cached_hostkey(
+    InteractionReadySeat iseat, const char *algname, const char **betteralgs,
+    void (*callback)(void *ctx, SeatPromptResult result), void *ctx);
 
 typedef struct ssh_transient_hostkey_cache ssh_transient_hostkey_cache;
 ssh_transient_hostkey_cache *ssh_transient_hostkey_cache_new(void);