X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/key/key.h

diff --git a/key/key.h b/key/key.h
new file mode 100644
index 0000000..bed3632
--- /dev/null
+++ b/key/key.h
@@ -0,0 +1,700 @@
+/* -*-c-*-
+ *
+ * Simple key management
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Catacomb is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with Catacomb; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#ifndef CATACOMB_KEY_H
+#define CATACOMB_KEY_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stdio.h>
+#include <time.h>
+
+#include <mLib/bits.h>
+#include <mLib/dstr.h>
+#include <mLib/hash.h>
+#include <mLib/sym.h>
+
+#ifndef CATACOMB_KEY_ERROR_H
+#  include "key-error.h"
+#endif
+
+#ifndef CATACOMB_KEY_DATA_H
+#  include "key-data.h"
+#endif
+
+#ifndef CATACOMB_GHASH_H
+#  include "ghash.h"
+#endif
+
+#ifndef CATACOMB_MP_H
+#  include "mp.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+/* --- Key attributes --- *
+ *
+ * Each attribute is stored as a symbol in a symbol table.  The value is
+ * the plain (not url-encoded) text to be written to the the file.  If the
+ * value is binary data, then by this point it's base-64 encoded.
+ */
+
+typedef struct key_attr {
+  sym_base _b;				/* Symbol table data */
+  char *p;				/* Pointer to attribute value */
+} key_attr;
+
+/* --- Main key structure --- *
+ *
+ * Each key is stored in two symbol tables, one indexed by keyid, and the
+ * other indexed by type.  Because many keys can have the same type, the type
+ * table contains a list of keys, sorted in descending order of expiry.
+ */
+
+typedef struct key {
+
+  /* --- Hashtable management --- */
+
+  hash_base _b;				/* Symbol table data */
+  struct key *next;			/* Next key of the same type */
+
+  /* --- Basic key attributes --- */
+
+  uint32 id;				/* Key id used to name it */
+  char *tag;				/* Textual tag name */
+  char *type;				/* Textual key type */
+  time_t exp, del;			/* Expiry times for keys */
+
+  /* --- The key data itself --- */
+
+  key_data *k;				/* The actual key data */
+
+  /* --- Other attributes and commentary --- */
+
+  sym_table a;				/* Hashtable of key attributes */
+  char *c;				/* Any additional comments */
+} key;
+
+/* --- The keys-by-type entries --- */
+
+typedef struct key_ref {
+  sym_base _b;				/* Symbol table data */
+  key *k;				/* Pointer to first key in list */
+} key_ref;
+
+/* --- A key file --- */
+
+typedef struct key_file {
+  FILE *fp;				/* File pointer open on file */
+  char *name;				/* Filename used to create it */
+  unsigned f;				/* Various useful flags */
+  hash_table byid;			/* Table of keys by keyid */
+  sym_table bytype;			/* Table of keys by type */
+  sym_table bytag;			/* Table of keys by tag */
+  size_t idload;			/* Loading on id table */
+} key_file;
+
+/* --- Key file flags --- */
+
+#define KF_WRITE 1u			/* File opened for writing */
+#define KF_MODIFIED 2u			/* File has been modified */
+
+/* --- Iterating over keys --- *
+ *
+ * Both of these are simple symbol table iterators, but they're made distinct
+ * types for the dubious benefits that type safety brings.
+ */
+
+typedef struct { hash_iter i; time_t t; } key_iter;
+typedef struct { sym_iter i; } key_attriter;
+
+/* --- Key fetching --- */
+
+typedef struct key_fetchdef {
+  char *name;				/* Name of item */
+  size_t off;				/* Offset into target structure */
+  unsigned e;				/* Flags for the item */
+  const struct key_fetchdef *kf;	/* Substructure pointer */
+} key_fetchdef;
+
+/* --- File opening options --- */
+
+#define KOPEN_READ 0u
+#define KOPEN_WRITE 1u
+#define KOPEN_MASK 0xff
+#define KOPEN_NOFILE 0x100
+
+/* --- Various other magic numbers --- */
+
+#define KEXP_FOREVER ((time_t)-1)	/* Never expire this key */
+#define KEXP_EXPIRE ((time_t)-2)	/* Expire this key when unused */
+
+/* --- Write error codes --- */
+
+enum {
+  KWRITE_OK,				/* Everything went fine */
+  KWRITE_FAIL = -1,			/* Close attempt failed */
+  KWRITE_BROKEN	= -2			/* Key ring needs manual fixing */
+};
+
+/* --- Error reporting functions for @key_merge@ and @key_open@ --- */
+
+typedef void key_reporter(const char */*file*/, int /*line*/,
+			  const char */*err*/, void */*p*/);
+
+/* --- Macros for testing expiry --- */
+
+#define KEY_EXPIRED(now, exp)						\
+  ((exp) == KEXP_EXPIRE || ((exp) != KEXP_FOREVER && (exp) < (now)))
+
+/*----- Reading and writing keys and files --------------------------------*/
+
+/* --- @key_merge@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file structure
+ *		@const char *file@ = name of file (for error messages)
+ *		@FILE *fp@ = file handle to read from
+ *		@key_reporter *rep@ = error reporting function
+ *		@void *arg@ = argument for function
+ *
+ * Returns:	Error code (one of the @KERR@ constants).
+ *
+ * Use:		Reads keys from a file, and inserts them into the file.
+ */
+
+extern int key_merge(key_file */*f*/, const char */*file*/, FILE */*fp*/,
+		     key_reporter */*rep*/, void */*arg*/);
+
+/* --- @key_extract@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file structure
+ *		@key *k@ = key to extract
+ *		@FILE *fp@ = file to write on
+ *		@const key_filter *kf@ = pointer to key selection block
+ *
+ * Returns:	Zero if OK, EOF on error.
+ *
+ * Use:		Extracts a key to an ouptut file.
+ */
+
+extern int key_extract(key_file */*f*/, key */*k*/, FILE */*fp*/,
+		       const key_filter */*kf*/);
+
+/* --- @key_open@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file structure to initialize
+ *		@const char *file@ = pointer to the file name
+ *		@unsigned how@ = opening options (@KOPEN_*@).
+ *		@key_reporter *rep@ = error reporting function
+ *		@void *arg@ = argument for function
+ *
+ * Returns:	Zero if it worked, nonzero otherwise.
+ *
+ * Use:		Opens a key file, reads its contents, and stores them in a
+ *		structure.  The file is locked appropriately until closed
+ *		using @key_close@.  On an error, everything is cleared away
+ *		tidily.  If the file is opened with @KOPEN_WRITE@, it's
+ *		created if necessary, with read and write permissions for its
+ *		owner only.
+ */
+
+extern int key_open(key_file */*f*/, const char */*file*/, unsigned /*how*/,
+		    key_reporter */*rep*/, void */*arg*/);
+
+/* --- @key_discard@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to key file block
+ *
+ * Returns:	---
+ *
+ * Use:		Frees all the key data, without writing changes.
+ */
+
+extern void key_discard(key_file */*f*/);
+
+/* --- @key_close@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to key file block
+ *
+ * Returns:	A @KWRITE_@ code indicating how it went.
+ *
+ * Use:		Frees all the key data, writes any changes.  Make sure that
+ *		all hell breaks loose if this returns @KWRITE_BROKEN@.
+ */
+
+extern int key_close(key_file */*f*/);
+
+/* --- @key_save@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to key file block
+ *
+ * Returns:	A @KWRITE_@ code indicating how well it worked.
+ *
+ * Use:		Writes a key file's data back to the actual file.  This code
+ *		is extremely careful about error handling.  It should usually
+ *		be able to back out somewhere sensible, but it can tell when
+ *		it's got itself into a real pickle and starts leaving well
+ *		alone.
+ *
+ *		Callers, please make sure that you ring alarm bells when this
+ *		function returns @KWRITE_BROKEN@.
+ */
+
+extern int key_save(key_file */*f*/);
+
+/* --- @key_lockfile@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file structure to initialize
+ *		@const char *file@ = pointer to the file name
+ *		@unsigned how@ = opening options (@KOPEN_*@).
+ *
+ * Returns:	Zero if it worked, nonzero otherwise.
+ *
+ * Use:		Opens a keyfile and stores the information needed for
+ *		continued access in the structure.
+ *
+ *		If the file is opened with @KOPEN_WRITE@, it's created if
+ *		necessary with read and write permissions for owner only, and
+ *		locked for update while it's open.
+ *
+ *		This is a system-dependent routine, and only really intended
+ *		for the private use of @key_open@.
+ */
+
+extern int key_lockfile(key_file */*f*/, const char */*file*/,
+			unsigned /*how*/);
+
+/*----- Creating and manipulating keys ------------------------------------*/
+
+/* --- @key_new@ ---
+ *
+ * Arguments:	@key_file *f@ = pointer to key file
+ *		@uint32 id@ = keyid to set
+ *		@const char *type@ = the type of this key
+ *		@time_t exp@ = when the key expires
+ *		@key *kk@ = where to put the key pointer
+ *
+ * Returns:	Error code (one of the @KERR@ constants).
+ *
+ * Use:		Attaches a new key to a key file.  You must have a writable
+ *		key file for this to work.
+ *
+ *		The type is a key type string.  This interface doesn't care
+ *		about how type strings are formatted: it just treats them as
+ *		opaque gobs of text.  Clients are advised to choose some
+ *		standard for representing key types, though.
+ *
+ *		The expiry time should either be a time in the future, or the
+ *		magic value @KEXP_FOREVER@ which means `never expire this
+ *		key'.  Be careful with `forever' keys.  If I were you, I'd
+ *		use a more sophisticated key management system than this for
+ *		them.
+ *
+ *		You have to set the actual key yourself.
+ */
+
+extern int key_new(key_file */*f*/, uint32 /*id*/, const char */*type*/,
+		   time_t /*exp*/, key **/*kk*/);
+
+/* --- @key_delete@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file block
+ *		@key *k@ = key to delete
+ *
+ * Returns:	Error code (one of the @KERR@ constants).
+ *
+ * Use:		Removes the given key from the list.  The key file must be
+ *		writable.  (Due to the horridness of the data structures,
+ *		deleted keys aren't actually removed, just marked so that
+ *		they can't be looked up or iterated over.  One upshot of
+ *		this is that they don't get written back to the file when
+ *		it's closed.)
+ */
+
+extern int key_delete(key_file */*f*/, key */*k*/);
+
+/* --- @key_expired@ --- *
+ *
+ * Arguments:	@key *k@ = pointer to key block
+ *
+ * Returns:	Zero if the key is OK, nonzero if it's expired.
+ */
+
+int key_expired(key */*k*/);
+
+/* --- @key_expire@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file block
+ *		@key *k@ = pointer to key block
+ *
+ * Returns:	Error code (one of the @KERR@ constants).
+ *
+ * Use:		Immediately marks the key as expired.  It may be removed
+ *		immediately, if it is no longer required, and will be removed
+ *		by a tidy operation when it is no longer required.  The key
+ *		file must be writable.
+ */
+
+extern int key_expire(key_file */*f*/, key */*k*/);
+
+/* --- @key_used@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to key file
+ *		@key *k@ = pointer to key block
+ *		@time_t t@ = when key can be removed
+ *
+ * Returns:	Zero if OK, nonzero on failure.
+ *
+ * Use:		Marks a key as being required until a given time.  Even
+ *		though the key may expire before then (and won't be returned
+ *		by type after that time), it will still be available when
+ *		requested explicitly by id.  The key file must be writable.
+ *
+ *		The only (current) reason for failure is attempting to use
+ *		a key which can expire for something which can't.
+ */
+
+extern int key_used(key_file */*f*/, key */*k*/, time_t /*t*/);
+
+/* --- @key_fingerprint@ --- *
+ *
+ * Arguments:	@key *k@ = the key to fingerprint
+ *		@ghash *h@ = the hash to use
+ *		@const key_filter *kf@ = filter to apply
+ *
+ * Returns:	Nonzero if the key slightly matched the filter.
+ *
+ * Use:		Updates the hash context with the key contents.
+ */
+
+extern int key_fingerprint(key */*k*/, ghash */*h*/,
+			   const key_filter */*kf*/);
+
+/*----- Setting and reading attributes ------------------------------------*/
+
+/* --- @key_chkident@ --- *
+ *
+ * Arguments:	@const char *p@ = pointer to a type string
+ *
+ * Returns:	Zero if OK, -1 on error.
+ *
+ * Use:		Checks whether an identification component string is OK.
+ */
+
+extern int key_chkident(const char */*p*/);
+
+/* --- @key_chkcomment@ --- *
+ *
+ * Arguments:	@const char *p@ = pointer to a comment string
+ *
+ * Returns:	Zero if OK, -1 on error.
+ *
+ * Use:		Checks whether a comment string is OK.
+ */
+
+extern int key_chkcomment(const char */*p*/);
+
+/* --- @key_setcomment@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to key file block
+ *		@key *k@ = pointer to key block
+ *		@const char *c@ = pointer to comment to set, or zero
+ *
+ * Returns:	Error code (one of the @KERR@ constants).
+ *
+ * Use:		Replaces the key's current comment with a new one.
+ */
+
+extern int key_setcomment(key_file */*f*/, key */*k*/, const char */*c*/);
+
+/* --- @key_settag@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to key file block
+ *		@key *k@ = pointer to key block
+ *		@const char *tag@ = pointer to comment to set, or zero
+ *
+ * Returns:	Error code (one of the @KERR@ constants).
+ *
+ * Use:		Replaces the key's current tag with a new one.
+ */
+
+extern int key_settag(key_file */*f*/, key */*k*/, const char */*tag*/);
+
+/* --- @key_setkeydata@ --- *
+ *
+ * Arguments:	@key_file *kf@ = pointer to key file
+ *		@key *k@ = pointer to key
+ *		@key_data *kd@ = new key data
+ *
+ * Returns:	Zero on success, or a @KERR_@ error code on failure.
+ *
+ * Use:		Sets the key data for a key.
+ */
+
+extern int key_setkeydata(key_file */*kf*/, key */*k*/, key_data */*kd*/);
+
+/* --- @key_fulltag@ --- *
+ *
+ * Arguments:	@key *k@ = pointer to key
+ *		@dstr *d@ = pointer to destination string
+ *
+ * Returns:	---
+ *
+ * Use:		Emits the key's full tag, which has the form
+ *		`ID:TYPE[:TAG]'.  This is used in the textual file format,
+ *		and to identify passphrases for locked keys.
+ */
+
+extern void key_fulltag(key */*k*/, dstr */*d*/);
+
+/* --- @key_qtag@ --- *
+ *
+ * Arguments:	@key_file *f@ = key file to find a key from
+ *		@const char *tag@ = pointer to tag string
+ *		@dstr *d@ = pointer to string for full tag name
+ *		@key **k@ = where to store the key pointer
+ *		@key_data ***kd@ = where to store the key data pointer
+ *
+ * Returns:	Zero if OK, nonzero if it failed.
+ *
+ * Use:		Performs a full lookup on a qualified tag name.  The tag is
+ *		qualified by the names of subkeys, separated by dots.  Hence,
+ *		a qualified tag is ID|TAG[.TAG...].  The various result
+ *		pointers can be null to indicate that the result isn't
+ *		interesting.
+ */
+
+extern int key_qtag(key_file */*f*/, const char */*tag*/,
+		    dstr */*d*/, key **/*k*/, key_data ***/*kd*/);
+
+/* --- @key_getattr@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file
+ *		@key *k@ = pointer to key
+ *		@const char *n@ = pointer to attribute name
+ *
+ * Returns:	Pointer to attribute value, or null if not found.
+ *
+ * Use:		Returns the value of a key attribute.
+ */
+
+extern const char *key_getattr(key_file */*f*/, key */*k*/,
+			       const char */*n*/);
+
+/* --- @key_putattr@ --- *
+ *
+ * Arguments:	@key_file *f@ = pointer to file
+ *		@key *k@ = pointer to key
+ *		@const char *n@ = pointer to attribute name
+ *		@const char *v@ = pointer to attribute value or null
+ *
+ * Returns:	Error code (one of the @KERR@ constants).
+ *
+ * Use:		Inserts an attribute on a key.  If an attribute with the same
+ *		name already exists, it is deleted.  Setting a null value
+ *		removes the attribute.
+ */
+
+extern int key_putattr(key_file */*f*/, key */*k*/,
+		       const char */*n*/, const char */*v*/);
+
+/* --- @key_mkattriter@ --- *
+ *
+ * Arguments:	@key_attriter *i@ = pointer to attribute iterator
+ *		@key *k@ = pointer to key
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes an attribute iterator.  The attributes are
+ *		returned by @key_nextattr@.
+ */
+
+extern void key_mkattriter(key_attriter */*i*/, key */*k*/);
+
+/* --- @key_nextattr@ --- *
+ *
+ * Arguments:	@key_attriter *i@ = pointer to attribute iterator
+ *		@const char **n, **v@ = pointers to name and value
+ *
+ * Returns:	Zero if no attribute available, or nonzero if returned OK.
+ *
+ * Use:		Returns the next attribute.
+ */
+
+extern int key_nextattr(key_attriter */*i*/,
+			const char **/*n*/, const char **/*v*/);
+
+/*----- Searching and iterating -------------------------------------------*/
+
+/* --- @key_bytype@ --- *
+ *
+ * Arguments:	@key_file *f@ = key file we want a key from
+ *		@const char *type@ = type string for desired key
+ *
+ * Returns:	Pointer to the best key to use, or null.
+ *
+ * Use:		Looks up a key by its type.  Returns the key with the latest
+ *		expiry time.  This function will not return an expired key.
+ */
+
+extern key *key_bytype(key_file */*f*/, const char */*type*/);
+
+/* --- @key_byid@ --- *
+ *
+ * Arguments:	@key_file *f@ = key file to find a key from
+ *		@uint32 id@ = id to look for
+ *
+ * Returns:	Key with matching id.
+ *
+ * Use:		Returns a key given its id.  This function will return an
+ *		expired key, but not a deleted one.
+ */
+
+extern key *key_byid(key_file */*f*/, uint32 /*id*/);
+
+/* --- @key_bytag@ --- *
+ *
+ * Arguments:	@key_file *f@ = key file to find a key from
+ *		@const char *tag@ = pointer to tag string
+ *
+ * Returns:	Key with matching id or tag.
+ *
+ * Use:		Returns a key given its tag or id.  This function will return
+ *		an expired key, but not a deleted one.
+ */
+
+extern key *key_bytag(key_file */*f*/, const char */*tag*/);
+
+/* --- @key_mkiter@ --- *
+ *
+ * Arguments:	@key_iter *i@ = pointer to iterator object
+ *		@key_file *f@ = pointer to file structure
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes a key iterator.  The keys are returned by
+ *		@key_next@.
+ */
+
+extern void key_mkiter(key_iter */*i*/, key_file */*f*/);
+
+/* --- @key_next@ --- *
+ *
+ * Arguments:	@key_iter *i@ = pointer to iterator object
+ *
+ * Returns:	Pointer to next key, or null.
+ *
+ * Use:		Returns the next key in some arbitrary sequence.
+ */
+
+extern key *key_next(key_iter */*i*/);
+
+/*----- Fetching key data conveniently ------------------------------------*/
+
+/* --- @key_fetchinit@ --- *
+ *
+ * Arguments:	@const key_fetchdef *kf@ = pointer to base definition
+ *		@key_packstruct *kps@ = pointer to destination packing def
+ *		@void *p@ = pointer to destination block
+ *
+ * Returns:	Pointer to packing definition.
+ *
+ * Use:		Initializes a packing definition (@key_packdef@ structure).
+ *		If @kps@ is null on entry, an appropriately sized block is
+ *		allocated automatically.  Otherwise it must be large enough.
+ */
+
+extern key_packdef *key_fetchinit(const key_fetchdef */*kf*/,
+				  key_packstruct */*kp*/, void */*p*/);
+
+/* --- @key_fetch@ --- *
+ *
+ * Arguments:	@key_packdef *kp@ = pointer to packing structure
+ *		@key *k@ = key file containing desired key
+ *
+ * Returns:	Error code, or zero.
+ *
+ * Use:		Fetches an unpacked key from a packed one.
+ */
+
+extern int key_fetch(key_packdef */*kp*/, key */*k*/);
+
+/* --- @key_fetchbyname@ --- *
+ *
+ * Arguments:	@key_packdef *kp@ = pointer to packing structure
+ *		@key_file *kf@ = key file containing desired key
+ *		@const char *tag@ = user's tag describing the key
+ *
+ * Returns:	Error code, or zero.
+ *
+ * Use:		Fetches a named key from a key file and unpacks it
+ *		conveniently.
+ */
+
+extern int key_fetchbyname(key_packdef */*kp*/,
+			   key_file */*kf*/, const char */*tag*/);
+
+/* --- @key_fetchdone@ --- *
+ *
+ * Arguments:	@key_packdef *kp@ = pointer to packing structure
+ *
+ * Returns:	---
+ *
+ * Use:		Frees a packing structure.  If the structure was allocated by
+ *		@key_fetchinit@ then it is freed.
+ */
+
+extern void key_fetchdone(key_packdef */*kp*/);
+
+/*----- Other functions ---------------------------------------------------*/
+
+/* --- @key_moan@ --- *
+ *
+ * Arguments:	@const char *file@ = name of the file
+ *		@int line@ = line number in file
+ *		@const char *msg@ = error message
+ *		@void *p@ = argument pointer
+ *
+ * Returns:	---
+ *
+ * Use:		Reports an error message about loading a key file.
+ */
+
+extern void key_moan(const char */*file*/, int /*line*/,
+		     const char */*msg*/, void */*p*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif