Rationalised host key storage. Also started code reorg: persistent-state

routines have been moved out into a replaceable module winstore.c.

[originally from svn r639]

storage.h

@@ -0,0 +1,88 @@
+/*
+ * storage.h: interface defining functions for storage and recovery
+ * of PuTTY's persistent data.
+ */
+
+#ifndef PUTTY_STORAGE_H
+#define PUTTY_STORAGE_H
+
+/* ----------------------------------------------------------------------
+ * Functions to save and restore PuTTY sessions. Note that this is
+ * only the low-level code to do the reading and writing. The
+ * higher-level code that translates a Config structure into a set
+ * of (key,value) pairs is elsewhere, since it doesn't (mostly)
+ * change between platforms.
+ */
+
+/*
+ * Write a saved session. The caller is expected to call
+ * open_setting_w() to get a `void *' handle, then pass that to a
+ * number of calls to write_setting_s() and write_setting_i(), and
+ * then close it using close_settings_w(). At the end of this call
+ * sequence the settings should have been written to the PuTTY
+ * persistent storage area.
+ */
+void *open_settings_w(char *sessionname);
+void write_setting_s(void *handle, char *key, char *value);
+void write_setting_i(void *handle, char *key, int value);
+void *close_settings_w(void *handle);
+
+/*
+ * Read a saved session. The caller is expected to call
+ * open_setting_r() to get a `void *' handle, then pass that to a
+ * number of calls to read_setting_s() and read_setting_i(), and
+ * then close it using close_settings_r().
+ * 
+ * read_setting_s() writes into the provided buffer and returns a
+ * pointer to the same buffer.
+ * 
+ * If a particular string setting is not present in the session,
+ * read_setting_s() can return NULL, in which case the caller
+ * should invent a sensible default. If an integer setting is not
+ * present, read_setting_i() returns its provided default.
+ */
+void *open_settings_r(char *sessionname);
+char *read_setting_s(void *handle, char *key, char *buffer, int buflen);
+int read_setting_i(void *handle, char *key, int defvalue);
+void *close_settings_r(void *handle);
+
+/* ----------------------------------------------------------------------
+ * Functions to access PuTTY's host key database.
+ */
+
+/*
+ * See if a host key matches the database entry. Return values can
+ * be 0 (entry matches database), 1 (entry is absent in database),
+ * or 2 (entry exists in database and is different).
+ */
+int verify_host_key(char *hostname, char *keytype, char *key);
+
+/*
+ * Write a host key into the database, overwriting any previous
+ * entry that might have been there.
+ */
+void store_host_key(char *hostname, char *keytype, char *key);
+
+/* ----------------------------------------------------------------------
+ * Functions to access PuTTY's random number seed file.
+ */
+
+typedef void (*noise_consumer_t)(void *data, size_t len);
+
+/*
+ * Read PuTTY's random seed file and pass its contents to a noise
+ * consumer function.
+ */
+void read_random_seed(noise_consumer_t consumer);
+
+/*
+ * Write PuTTY's random seed file from a given chunk of noise.
+ */
+void write_random_seed(void *data, size_t len);
+
+/* ----------------------------------------------------------------------
+ * Cleanup function: remove all of PuTTY's persistent state.
+ */
+void cleanup_all(void);
+
+#endif