/* -*-c-*-
*
- * $Id: key.h,v 1.1 1999/09/03 08:41:12 mdw Exp $
+ * $Id: key.h,v 1.3 1999/12/22 15:47:48 mdw Exp $
*
* Simple key management
*
- * (c) 1999 Mark Wooding
+ * (c) 1999 Straylight/Edgeware
*/
/*----- Licensing notice --------------------------------------------------*
/*----- Revision history --------------------------------------------------*
*
* $Log: key.h,v $
+ * Revision 1.3 1999/12/22 15:47:48 mdw
+ * Major key-management revision.
+ *
+ * Revision 1.2 1999/12/10 23:29:48 mdw
+ * Change header file guard names.
+ *
* Revision 1.1 1999/09/03 08:41:12 mdw
* Initial import.
*
*/
-#ifndef KEY_H
-#define KEY_H
+#ifndef CATACOMB_KEY_H
+#define CATACOMB_KEY_H
#ifdef __cplusplus
extern "C" {
#include <time.h>
#include <mLib/bits.h>
+#include <mLib/dstr.h>
#include <mLib/hash.h>
#include <mLib/sym.h>
+#ifndef CATACOMB_MP_H
+# include "mp.h"
+#endif
+
/*----- Data structures ---------------------------------------------------*/
/* --- Key attributes --- *
char *p; /* Pointer to attribute value */
} key_attr;
+/* --- Key data structure --- */
+
+typedef struct key_data {
+ unsigned e; /* Encoding type for key data */
+ union {
+
+ /* --- Plain binary key data --- *
+ *
+ * Also used for encrypted key types.
+ */
+
+ struct {
+ octet *k; /* Actual key data */
+ size_t sz; /* Size of the key data */
+ } k; /* Plain binary key */
+
+ /* --- Multiprecision integer keys --- */
+
+ mp *m; /* Multiprecision integer */
+
+ /* --- Structured key data --- */
+
+ sym_table s; /* Structured key data */
+ } u;
+} key_data;
+
+typedef struct key_struct {
+ sym_base _b;
+ key_data k;
+} key_struct;
+
+/* --- Key binary encoding --- *
+ *
+ * The binary encoding consists of a header containing a 16-bit encoding type
+ * and a 16-bit length, followed immediately by the key data, followed by
+ * between zero and three zero bytes to make the total length a multiple of
+ * four. The format of the following data depends on the encoding type:
+ *
+ * @KENC_BINARY@ Binary data.
+ *
+ * @KENC_MP@ Octet array interpreted in big-endian byte order.
+ *
+ * @KENC_STRUCT@ An array of pairs, each containing a string (8-bit
+ * length followed by data and zero-padding to 4-byte
+ * boundary) and key binary encodings.
+ *
+ * @KENC_ENCRYPT@ Binary data, format
+ */
+
+/* --- Key encoding methods and other flags--- */
+
+enum {
+
+ /* --- Bottom two bits are the encoding type --- */
+
+ KF_ENCMASK = 0x03, /* Encoding mask */
+ KENC_BINARY = 0x00, /* Plain binary key (@k@) */
+ KENC_MP = 0x01, /* Multiprecision integer (@i@) */
+ KENC_STRUCT = 0x02, /* Structured key data (@s@) */
+ KENC_ENCRYPT = 0x03, /* Encrypted key type (@k@) */
+
+ /* --- Key category bits --- */
+
+ KF_CATMASK = 0x0c, /* Category mask */
+ KCAT_SYMM = 0x00, /* Symmetric encryption key */
+ KCAT_PRIV = 0x04, /* Private (asymmetric) key */
+ KCAT_PUB = 0x08, /* Public (asymmetric) key */
+ KCAT_SHARE = 0x0c, /* Shared (asymmetric) key */
+ KF_NONSECRET = 0x08, /* Bit flag for non-secret keys */
+
+ /* --- Other flags --- */
+
+ KF_BURN = 0x10, /* Burn key after use */
+
+ /* --- Tag end --- */
+
+ KENC_MAX /* Dummy limit constant */
+};
+
+/* --- Key flag filtering --- */
+
+typedef struct key_filter {
+ unsigned f;
+ unsigned m;
+} key_filter;
+
+/* --- Matching aginst key selection --- */
+
+#define KEY_MATCH(kd, kf) \
+ (!(kf) || \
+ ((kd)->e & KF_ENCMASK) == KENC_STRUCT || \
+ ((kd)->e & (kf)->m) == (kf)->f)
+
/* --- Main key structure --- *
*
* Each key is stored in two symbol tables, one indexed by keyid, and the
*/
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 */
- void *k; /* Actual key data */
- size_t ksz; /* Size of the key data */
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_type {
+typedef struct key_ref {
sym_base _b; /* Symbol table data */
key *k; /* Pointer to first key in list */
-} key_type;
+} key_ref;
/* --- A key file --- */
typedef struct key_file {
FILE *fp; /* File pointer open on file */
- int fd; /* File descriptor 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;
/* --- Various other magic numbers --- */
-#define KEXP_UNUSED ((time_t)0) /* Key has never been used */
#define KEXP_FOREVER ((time_t)-1) /* Never expire this key */
#define KEXP_EXPIRE ((time_t)-2) /* Expire this key when unused */
-/* --- Write attempt codes --- */
+/* --- Key error codes --- */
+
+enum {
+ KERR_OK, /* No error */
+ KERR_BADTAG = -1, /* Malformed tag string */
+ KERR_BADTYPE = -2, /* Malformed type string */
+ KERR_BADCOMMENT = -3, /* Malformed comment string */
+ KERR_DUPID = -4, /* Duplicate keyid */
+ KERR_DUPTAG = -5, /* Duplicate key tag string */
+ KERR_READONLY = -6, /* Key file is read-only */
+ KERR_WILLEXPIRE = -7, /* Key will eventually expire */
+ KERR_EXPIRED = -8, /* Key has already expired */
+ KERR_BADFLAGS = -9, /* Error in flags string */
+ KERR_MAX /* Largest possible error */
+};
+
+/* --- Write error codes --- */
enum {
KWRITE_OK, /* Everything went fine */
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)))
-#define KEY_DELETED(now, del) ((del) == KEXP_FOREVER || (del) < (now))
+/*----- Key data manipulation ---------------------------------------------*/
+
+/* --- @key_destroy@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data to destroy
+ *
+ * Returns: ---
+ *
+ * Use: Destroys a lump of key data.
+ */
-/*----- Functions provided ------------------------------------------------*/
+extern void key_destroy(key_data */*k*/);
-/* --- @key_chktype@ --- *
+/* --- @key_readflags@ --- *
*
- * Arguments: @const char *type@ = pointer to a type string
+ * Arguments: @const char *p@ = pointer to string to read
+ * @char **pp@ = where to store the end pointer
+ * @unsigned *ff@ = where to store the flags
+ * @unsigned *mm@ = where to store the mask
*
- * Returns: Zero if OK, -1 on error.
+ * Returns: Zero if all went well, nonzero if there was an error.
*
- * Use: Checks whether a type string is OK.
+ * Use: Reads a flag string.
*/
-extern int key_chktype(const char */*type*/);
+extern int key_readflags(const char */*p*/, char **/*pp*/,
+ unsigned */*ff*/, unsigned */*mm*/);
-/* --- @key_chkcomment@ --- *
+/* --- @key_writeflags@ --- *
*
- * Arguments: @const char *comment@ = pointer to a comment string
+ * Arguments: @unsigned f@ = flags to write
+ * @dstr *d@ = pointer to destination string
*
- * Returns: Zero if OK, -1 on error.
+ * Returns: ---
*
- * Use: Checks whether a comment string is OK.
+ * Use: Emits a flags word as a string representation.
*/
-extern int key_chkcomment(const char */*c*/);
+extern void key_writeflags(unsigned /*f*/, dstr */*d*/);
-/* --- @key_mkiter@ --- *
+/* --- @key_binary@ --- *
*
- * Arguments: @key_iter *i@ = pointer to iterator object
- * @key_file *f@ = pointer to file structure
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const void *p@ = pointer to key data
+ * @size_t sz@ = size of the key data
*
* Returns: ---
*
- * Use: Initializes a key iterator. The keys are returned by
- * @key_next@.
+ * Use: Sets a binary key in a key data block.
*/
-extern void key_mkiter(key_iter */*i*/, key_file */*f*/);
+extern void key_binary(key_data */*k*/, const void */*p*/, size_t /*sz*/);
-/* --- @key_next@ --- *
+/* --- @key_encrypted@ --- *
*
- * Arguments: @key_iter *i@ = pointer to iterator object
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const void *p@ = pointer to key data
+ * @size_t sz@ = size of the key data
*
- * Returns: Pointer to next key, or null.
+ * Returns: ---
*
- * Use: Returns the next key in some arbitrary sequence.
+ * Use: Sets an encrypted key in a key data block.
*/
-extern key *key_next(key_iter */*i*/);
+extern void key_encrypted(key_data */*k*/, const void */*p*/, size_t /*sz*/);
-/* --- @key_mkattriter@ --- *
+/* --- @key_mp@ --- *
*
- * Arguments: @key_attriter *i@ = pointer to attribute iterator
- * @key_file *f@ = pointer to key file
- * @key *k@ = pointer to key
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @mp *m@ = pointer to the value to set
*
* Returns: ---
*
- * Use: Initializes an attribute iterator. The attributes are
- * returned by @key_nextattr@.
+ * Use: Sets a multiprecision integer key in a key block.
*/
-extern void key_mkattriter(key_attriter */*i*/, key_file */*f*/, key */*k*/);
+extern void key_mp(key_data */*k*/, mp */*m*/);
-/* --- @key_nextattr@ --- *
+/* --- @key_structure@ --- *
*
- * Arguments: @key_attriter *i@ = pointer to attribute iterator
- * @const char **n, **v@ = pointers to name and value
+ * Arguments: @key_data *k@ = pointer to key data block
*
- * Returns: Zero if no attribute available, or nonzero if returned OK.
+ * Returns: ---
*
- * Use: Returns the next attribute.
+ * Use: Initializes a structured key type.
*/
-extern int key_nextattr(key_attriter */*i*/,
- const char **/*n*/, const char **/*v*/);
+extern void key_structure(key_data */*k*/);
-/* --- @key_bytype@ --- *
+/* --- @key_structfind@ --- *
*
- * Arguments: @key_file *f@ = key file we want a key from
- * @const char *type@ = type string for desired key
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const char *tag@ = pointer to tag string
*
- * Returns: Pointer to the best key to use, or null.
+ * Returns: Pointer to key data block, 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.
+ * Use: Looks up the tag in a structured key.
*/
-extern key *key_bytype(key_file */*f*/, const char */*type*/);
+extern key_data *key_structfind(key_data */*k*/, const char */*tag*/);
-/* --- @key_byid@ --- *
+/* --- @key_structcreate@ --- *
*
- * Arguments: @key_file *f@ = key file to find a key from
- * @uint32 id@ = id to look for
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const char *tag@ = pointer to tag string
*
- * Returns: Key with matching id.
+ * Returns: Pointer to newly created key data.
*
- * Use: Returns a key given its id. This function will return an
- * expired key, but not a deleted one.
+ * Use: Creates a new uninitialized subkey.
*/
-extern key *key_byid(key_file */*f*/, uint32 /*id*/);
+extern key_data *key_structcreate(key_data */*k*/, const char */*tag*/);
-/* --- @key_getattr@ --- *
+/* --- @key_match@ --- *
*
- * Arguments: @key_file *f@ = pointer to file
- * @key *k@ = pointer to key
- * @const char *n@ = pointer to attribute name
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const key_filter *kf@ = pointer to filter block
*
- * Returns: Pointer to attribute value, or null if not found.
+ * Returns: Nonzero if the key matches the filter.
*
- * Use: Returns the value of a key attribute.
+ * Use: Checks whether a key matches a filter.
*/
-extern const char *key_getattr(key_file */*f*/, key */*k*/,
- const char */*n*/);
+extern int key_match(key_data */*k*/, const key_filter */*kf*/);
-/* --- @key_putattr@ --- *
+/* --- @key_do@ --- *
*
- * 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
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @const key_filter *kf@ = pointer to filter block
+ * @dstr *d@ = pointer to base string
+ * @int (*func)(key_data *kd, dstr *d, void *p@ = function
+ * @void *p@ = argument to function
*
- * Returns: ---
+ * Returns: Nonzero return code from function, or zero.
*
- * Use: Inserts an attribute on a key. If an attribute with the same
- * name already exists, it is deleted.
+ * Use: Runs a function over all the leaves of a key.
*/
-extern void key_putattr(key_file */*f*/, key */*k*/,
- const char */*n*/, const char */*v*/);
+extern int key_do(key_data */*k*/, const key_filter */*kf*/, dstr */*d*/,
+ int (*/*func*/)(key_data */*kd*/,
+ dstr */*d*/, void */*p*/),
+ void */*p*/);
-/* --- @key_setcomment@ --- *
+/* --- @key_copy@ --- *
*
- * 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
+ * Arguments: @key_data *kd@ = pointer to destination data block
+ * @key_data *k@ = pointer to source data block
+ * @const key_filter *kf@ = pointer to filter block
*
- * Returns: ---
+ * Returns: Nonzero if an item was actually copied.
*
- * Use: Replaces the key's current comment with a new one.
+ * Use: Copies a chunk of key data from one place to another.
+ */
+
+extern int key_copy(key_data */*kd*/, key_data */*k*/,
+ const key_filter */*kf*/);
+
+/* --- @key_read@ --- *
+ *
+ * Arguments: @const char *p@ = pointer to textual key representation
+ * @key_data *k@ = pointer to output block for key data
+ * @char **pp@ = where to store the end pointer
+ *
+ * Returns: Zero if all went well, nonzero if there was a problem.
+ *
+ * Use: Parses a textual key description.
+ */
+
+extern int key_read(const char */*p*/, key_data */*k*/, char **/*pp*/);
+
+/* --- @key_write@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data
+ * @dstr *d@ = destination string to write on
+ * @const key_filter *kf@ = pointer to key selection block
+ *
+ * Returns: Nonzero if any items were actually written.
+ *
+ * Use: Writes a key in a textual encoding.
+ */
+
+extern int key_write(key_data */*k*/, dstr */*d*/,
+ const key_filter */*kf*/);
+
+/* --- @key_decode@ --- *
+ *
+ * Arguments: @const void *p@ = pointer to buffer to read
+ * @size_t sz@ = size of the buffer
+ * @key_data *k@ = pointer to key data block to write to
+ *
+ * Returns: Zero if everything worked, nonzero otherwise.
+ *
+ * Use: Decodes a binary representation of a key.
+ */
+
+extern int key_decode(const void */*p*/, size_t /*sz*/, key_data */*k*/);
+
+/* --- @key_encode@ --- *
+ *
+ * Arguments: @key_data *k@ = pointer to key data block
+ * @dstr *d@ = pointer to destination string
+ * @const key_filter *kf@ = pointer to key selection block
+ *
+ * Returns: Nonzero if any items were actually written.
+ *
+ * Use: Encodes a key block as binary data.
+ */
+
+extern int key_encode(key_data */*k*/, dstr */*d*/,
+ const key_filter */*kf*/);
+
+/* --- @key_plock@ --- *
+ *
+ * Arguments: @const char *tag@ = tag to use for passphrase
+ * @key_data *k@ = source key data block
+ * @key_data *kt@ = target key data block
+ *
+ * Returns: Zero if successful, nonzero if there was a problem.
+ *
+ * Use: Locks a key by encrypting it with a passphrase.
+ */
+
+extern int key_plock(const char */*tag*/, key_data */*k*/, key_data */*kt*/);
+
+/* --- @key_punlock@ --- *
+ *
+ * Arguments: @const char *tag@ = tag to use for passphrase
+ * @key_data *k@ = source key data block
+ * @key_data *kt@ = target key data block
+ *
+ * Returns: Zero if it worked, nonzero if it didn't.
+ *
+ * Use: Unlocks a passphrase-locked key.
*/
-extern void key_setcomment(key_file */*f*/, key */*k*/, const char */*c*/);
+extern int key_punlock(const char */*tag*/,
+ key_data */*k*/, key_data */*kt*/);
+
+/*----- 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: ---
+ * Returns: Error code (one of the @KERR@ constants).
*
* Use: Reads keys from a file, and inserts them into the file.
*/
-extern void key_merge(key_file */*f*/, const char */*file*/, FILE */*fp*/);
+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*/);
-
-/* --- @key_write@ --- *
- *
- * 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_write(key_file */*f*/);
+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
* @int how@ = opening options (@KOPEN_*@).
+ * @key_reporter *rep@ = error reporting function
+ * @void *arg@ = argument for function
*
* Returns: Zero if it worked, nonzero otherwise.
*
* owner only.
*/
-extern int key_open(key_file */*f*/, const char */*file*/, int /*how*/);
+extern int key_open(key_file */*f*/, const char */*file*/, int /*how*/,
+ key_reporter */*rep*/, void */*arg*/);
/* --- @key_close@ --- *
*
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
+ * @int 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*/, int /*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
- * @const void *k@ = pointer to key data
- * @size_t ksz@ = size of key data
* @time_t exp@ = when the key expires
- * @const char *c@ = textual comment to attach
+ * @int *err@ = where to store the error condition
*
* Returns: Key block containing new data, or null if it couldn't be
* done.
* opaque gobs of text. Clients are advised to choose some
* standard for representing key types, though.
*
- * The key can be any old binary mess.
- *
* 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.
*
- * The comment can be any old text not containing newlines or
- * nulls. This interface doesn't impose any length restrictions
- * on comment lengths.
+ * You have to set the actual key yourself.
*/
-extern key *key_new(key_file */*f*/, const char */*type*/,
- const void */*k*/, size_t /*ksz*/,
- time_t /*exp*/, const char */*c*/);
+extern key *key_new(key_file */*f*/, uint32 /*id*/, const char */*type*/,
+ time_t /*exp*/, int */*err*/);
/* --- @key_delete@ --- *
*
* Arguments: @key_file *f@ = pointer to file block
* @key *k@ = key to delete
*
- * Returns: ---
+ * 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,
* it's closed.)
*/
-extern void key_delete(key_file */*f*/, key */*k*/);
+extern int key_delete(key_file */*f*/, key */*k*/);
/* --- @key_expire@ --- *
*
* Arguments: @key_file *f@ = pointer to file block
* @key *k@ = pointer to key block
*
- * Returns: ---
+ * 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
* file must be writable.
*/
-extern void key_expire(key_file */*f*/, key */*k*/);
+extern int key_expire(key_file */*f*/, key */*k*/);
/* --- @key_used@ --- *
*
extern int key_used(key_file */*f*/, key */*k*/, time_t /*t*/);
+/*----- 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_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*/);
+
+/*----- 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*/);
+
+/* --- @key_strerror@ --- *
+ *
+ * Arguments: @int err@ = error code from @key_new@
+ *
+ * Returns: Pointer to error string.
+ *
+ * Use: Translates a @KERR@ error code into a human-readable string.
+ */
+
+extern const char *key_strerror(int /*err*/);
+
/*----- That's all, folks -------------------------------------------------*/
#ifdef __cplusplus