dst.h revision ec5347e2c775f027573ce5648b910361aa926c01
/*
* Copyright (C) 2004-2006 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 2000-2002 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: dst.h,v 1.8 2007/06/18 23:47:43 tbox Exp $ */
#ifndef DST_DST_H
#define DST_DST_H 1
/*! \file dst/dst.h */
#include <isc/lang.h>
#include <dns/types.h>
#include <dst/gssapi.h>
ISC_LANG_BEGINDECLS
/***
*** Types
***/
/*%
* The dst_key structure is opaque. Applications should use the accessor
* functions provided to retrieve key attributes. If an application needs
* to set attributes, new accessor functions will be written.
*/
typedef struct dst_key dst_key_t;
typedef struct dst_context dst_context_t;
/* DST algorithm codes */
#define DST_ALG_UNKNOWN 0
#define DST_ALG_RSAMD5 1
#define DST_ALG_RSA DST_ALG_RSAMD5 /*%< backwards compatibility */
#define DST_ALG_DH 2
#define DST_ALG_DSA 3
#define DST_ALG_ECC 4
#define DST_ALG_RSASHA1 5
#define DST_ALG_HMACMD5 157
#define DST_ALG_GSSAPI 160
#define DST_ALG_HMACSHA1 161 /* XXXMPA */
#define DST_ALG_HMACSHA224 162 /* XXXMPA */
#define DST_ALG_HMACSHA256 163 /* XXXMPA */
#define DST_ALG_HMACSHA384 164 /* XXXMPA */
#define DST_ALG_HMACSHA512 165 /* XXXMPA */
#define DST_ALG_PRIVATE 254
#define DST_ALG_EXPAND 255
#define DST_MAX_ALGS 255
/*% A buffer of this size is large enough to hold any key */
#define DST_KEY_MAXSIZE 1280
/*%
* A buffer of this size is large enough to hold the textual representation
* of any key
*/
#define DST_KEY_MAXTEXTSIZE 2048
/*% 'Type' for dst_read_key() */
#define DST_TYPE_KEY 0x1000000 /* KEY key */
#define DST_TYPE_PRIVATE 0x2000000
#define DST_TYPE_PUBLIC 0x4000000
/***
*** Functions
***/
isc_result_t
dst_lib_init(isc_mem_t *mctx, isc_entropy_t *ectx, unsigned int eflags);
/*%<
* Initializes the DST subsystem.
*
* Requires:
* \li "mctx" is a valid memory context
* \li "ectx" is a valid entropy context
*
* Returns:
* \li ISC_R_SUCCESS
* \li ISC_R_NOMEMORY
*
* Ensures:
* \li DST is properly initialized.
*/
void
dst_lib_destroy(void);
/*%<
* Releases all resources allocated by DST.
*/
isc_boolean_t
dst_algorithm_supported(unsigned int alg);
/*%<
* Checks that a given algorithm is supported by DST.
*
* Returns:
* \li ISC_TRUE
* \li ISC_FALSE
*/
isc_result_t
dst_context_create(dst_key_t *key, isc_mem_t *mctx, dst_context_t **dctxp);
/*%<
* Creates a context to be used for a sign or verify operation.
*
* Requires:
* \li "key" is a valid key.
* \li "mctx" is a valid memory context.
* \li dctxp != NULL && *dctxp == NULL
*
* Returns:
* \li ISC_R_SUCCESS
* \li ISC_R_NOMEMORY
*
* Ensures:
* \li *dctxp will contain a usable context.
*/
void
dst_context_destroy(dst_context_t **dctxp);
/*%<
* Destroys all memory associated with a context.
*
* Requires:
* \li *dctxp != NULL && *dctxp == NULL
*
* Ensures:
* \li *dctxp == NULL
*/
isc_result_t
dst_context_adddata(dst_context_t *dctx, const isc_region_t *data);
/*%<
* Incrementally adds data to the context to be used in a sign or verify
* operation.
*
* Requires:
* \li "dctx" is a valid context
* \li "data" is a valid region
*
* Returns:
* \li ISC_R_SUCCESS
* \li DST_R_SIGNFAILURE
* \li all other errors indicate failure
*/
isc_result_t
dst_context_sign(dst_context_t *dctx, isc_buffer_t *sig);
/*%<
* Computes a signature using the data and key stored in the context.
*
* Requires:
* \li "dctx" is a valid context.
* \li "sig" is a valid buffer.
*
* Returns:
* \li ISC_R_SUCCESS
* \li DST_R_VERIFYFAILURE
* \li all other errors indicate failure
*
* Ensures:
* \li "sig" will contain the signature
*/
isc_result_t
dst_context_verify(dst_context_t *dctx, isc_region_t *sig);
/*%<
* Verifies the signature using the data and key stored in the context.
*
* Requires:
* \li "dctx" is a valid context.
* \li "sig" is a valid region.
*
* Returns:
* \li ISC_R_SUCCESS
* \li all other errors indicate failure
*
* Ensures:
* \li "sig" will contain the signature
*/
isc_result_t
dst_key_computesecret(const dst_key_t *pub, const dst_key_t *priv,
isc_buffer_t *secret);
/*%<
* Computes a shared secret from two (Diffie-Hellman) keys.
*
* Requires:
* \li "pub" is a valid key that can be used to derive a shared secret
* \li "priv" is a valid private key that can be used to derive a shared secret
* \li "secret" is a valid buffer
*
* Returns:
* \li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
* \li If successful, secret will contain the derived shared secret.
*/
isc_result_t
dst_key_fromfile(dns_name_t *name, dns_keytag_t id, unsigned int alg, int type,
const char *directory, isc_mem_t *mctx, dst_key_t **keyp);
/*%<
* Reads a key from permanent storage. The key can either be a public or
* private key, and is specified by name, algorithm, and id. If a private key
* is specified, the public key must also be present. If directory is NULL,
* the current directory is assumed.
*
* Requires:
* \li "name" is a valid absolute dns name.
* \li "id" is a valid key tag identifier.
* \li "alg" is a supported key algorithm.
* \li "type" is DST_TYPE_PUBLIC, DST_TYPE_PRIVATE, or the bitwise union.
* DST_TYPE_KEY look for a KEY record otherwise DNSKEY
* \li "mctx" is a valid memory context.
* \li "keyp" is not NULL and "*keyp" is NULL.
*
* Returns:
* \li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
* \li If successful, *keyp will contain a valid key.
*/
isc_result_t
dst_key_fromnamedfile(const char *filename, int type, isc_mem_t *mctx,
dst_key_t **keyp);
/*%<
* Reads a key from permanent storage. The key can either be a public or
* key, and is specified by filename. If a private key is specified, the
* public key must also be present.
*
* Requires:
* \li "filename" is not NULL
* \li "type" is DST_TYPE_PUBLIC, DST_TYPE_PRIVATE, or the bitwise union
* DST_TYPE_KEY look for a KEY record otherwise DNSKEY
* \li "mctx" is a valid memory context
* \li "keyp" is not NULL and "*keyp" is NULL.
*
* Returns:
* \li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
* \li If successful, *keyp will contain a valid key.
*/
isc_result_t
dst_key_read_public(const char *filename, int type,
isc_mem_t *mctx, dst_key_t **keyp);
/*%<
* Reads a public key from permanent storage. The key must be a public key.
*
* Requires:
* \li "filename" is not NULL
* \li "type" is DST_TYPE_KEY look for a KEY record otherwise DNSKEY
* \li "mctx" is a valid memory context
* \li "keyp" is not NULL and "*keyp" is NULL.
*
* Returns:
* \li ISC_R_SUCCESS
* \li DST_R_BADKEYTYPE if the key type is not the expected one
* \li ISC_R_UNEXPECTEDTOKEN if the file can not be parsed as a public key
* \li any other result indicates failure
*
* Ensures:
* \li If successful, *keyp will contain a valid key.
*/
isc_result_t
dst_key_tofile(const dst_key_t *key, int type, const char *directory);
/*%<
* Writes a key to permanent storage. The key can either be a public or
* private key. Public keys are written in DNS format and private keys
* are written as a set of base64 encoded values. If directory is NULL,
* the current directory is assumed.
*
* Requires:
* \li "key" is a valid key.
* \li "type" is DST_TYPE_PUBLIC, DST_TYPE_PRIVATE, or the bitwise union
*
* Returns:
* \li ISC_R_SUCCESS
* \li any other result indicates failure
*/
isc_result_t
dst_key_fromdns(dns_name_t *name, dns_rdataclass_t rdclass,
isc_buffer_t *source, isc_mem_t *mctx, dst_key_t **keyp);
/*%<
* Converts a DNS KEY record into a DST key.
*
* Requires:
* \li "name" is a valid absolute dns name.
* \li "source" is a valid buffer. There must be at least 4 bytes available.
* \li "mctx" is a valid memory context.
* \li "keyp" is not NULL and "*keyp" is NULL.
*
* Returns:
* \li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
* \li If successful, *keyp will contain a valid key, and the consumed
* pointer in data will be advanced.
*/
isc_result_t
dst_key_todns(const dst_key_t *key, isc_buffer_t *target);
/*%<
* Converts a DST key into a DNS KEY record.
*
* Requires:
* \li "key" is a valid key.
* \li "target" is a valid buffer. There must be at least 4 bytes unused.
*
* Returns:
* \li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
* \li If successful, the used pointer in 'target' is advanced by at least 4.
*/
isc_result_t
dst_key_frombuffer(dns_name_t *name, unsigned int alg,
unsigned int flags, unsigned int protocol,
dns_rdataclass_t rdclass,
isc_buffer_t *source, isc_mem_t *mctx, dst_key_t **keyp);
/*%<
* Converts a buffer containing DNS KEY RDATA into a DST key.
*
* Requires:
*\li "name" is a valid absolute dns name.
*\li "alg" is a supported key algorithm.
*\li "source" is a valid buffer.
*\li "mctx" is a valid memory context.
*\li "keyp" is not NULL and "*keyp" is NULL.
*
* Returns:
*\li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
*\li If successful, *keyp will contain a valid key, and the consumed
* pointer in source will be advanced.
*/
isc_result_t
dst_key_tobuffer(const dst_key_t *key, isc_buffer_t *target);
/*%<
* Converts a DST key into DNS KEY RDATA format.
*
* Requires:
*\li "key" is a valid key.
*\li "target" is a valid buffer.
*
* Returns:
*\li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
*\li If successful, the used pointer in 'target' is advanced.
*/
isc_result_t
dst_key_privatefrombuffer(dst_key_t *key, isc_buffer_t *buffer);
/*%<
* Converts a public key into a private key, reading the private key
* information from the buffer. The buffer should contain the same data
* as the .private key file would.
*
* Requires:
*\li "key" is a valid public key.
*\li "buffer" is not NULL.
*
* Returns:
*\li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
*\li If successful, key will contain a valid private key.
*/
gss_ctx_id_t
dst_key_getgssctx(const dst_key_t *key);
/*%<
* Returns the opaque key data.
* Be cautions when using this value unless you know what you are doing.
*
* Requires:
*\li "key" is not NULL.
*
* Returns:
*\li gssctx key data, possibly NULL.
*/
isc_result_t
dst_key_fromgssapi(dns_name_t *name, gss_ctx_id_t gssctx, isc_mem_t *mctx,
dst_key_t **keyp);
/*%<
* Converts a GSSAPI opaque context id into a DST key.
*
* Requires:
*\li "name" is a valid absolute dns name.
*\li "gssctx" is a GSSAPI context id.
*\li "mctx" is a valid memory context.
*\li "keyp" is not NULL and "*keyp" is NULL.
*
* Returns:
*\li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
*\li If successful, *keyp will contain a valid key and be responsible for
* the context id.
*/
isc_result_t
dst_key_generate(dns_name_t *name, unsigned int alg,
unsigned int bits, unsigned int param,
unsigned int flags, unsigned int protocol,
dns_rdataclass_t rdclass,
isc_mem_t *mctx, dst_key_t **keyp);
/*%<
* Generate a DST key (or keypair) with the supplied parameters. The
* interpretation of the "param" field depends on the algorithm:
* \code
* RSA: exponent
* 0 use exponent 3
* !0 use Fermat4 (2^16 + 1)
* DH: generator
* 0 default - use well known prime if bits == 768 or 1024,
* otherwise use 2 as the generator.
* !0 use this value as the generator.
* DSA: unused
* HMACMD5: entropy
* 0 default - require good entropy
* !0 lack of good entropy is ok
*\endcode
*
* Requires:
*\li "name" is a valid absolute dns name.
*\li "keyp" is not NULL and "*keyp" is NULL.
*
* Returns:
*\li ISC_R_SUCCESS
* \li any other result indicates failure
*
* Ensures:
*\li If successful, *keyp will contain a valid key.
*/
isc_boolean_t
dst_key_compare(const dst_key_t *key1, const dst_key_t *key2);
/*%<
* Compares two DST keys.
*
* Requires:
*\li "key1" is a valid key.
*\li "key2" is a valid key.
*
* Returns:
*\li ISC_TRUE
* \li ISC_FALSE
*/
isc_boolean_t
dst_key_paramcompare(const dst_key_t *key1, const dst_key_t *key2);
/*%<
* Compares the parameters of two DST keys. This is used to determine if
* two (Diffie-Hellman) keys can be used to derive a shared secret.
*
* Requires:
*\li "key1" is a valid key.
*\li "key2" is a valid key.
*
* Returns:
*\li ISC_TRUE
* \li ISC_FALSE
*/
void
dst_key_free(dst_key_t **keyp);
/*%<
* Release all memory associated with the key.
*
* Requires:
*\li "keyp" is not NULL and "*keyp" is a valid key.
*
* Ensures:
*\li All memory associated with "*keyp" will be freed.
*\li *keyp == NULL
*/
/*%<
* Accessor functions to obtain key fields.
*
* Require:
*\li "key" is a valid key.
*/
dns_name_t *
dst_key_name(const dst_key_t *key);
unsigned int
dst_key_size(const dst_key_t *key);
unsigned int
dst_key_proto(const dst_key_t *key);
unsigned int
dst_key_alg(const dst_key_t *key);
isc_uint32_t
dst_key_flags(const dst_key_t *key);
dns_keytag_t
dst_key_id(const dst_key_t *key);
dns_rdataclass_t
dst_key_class(const dst_key_t *key);
isc_boolean_t
dst_key_isprivate(const dst_key_t *key);
isc_boolean_t
dst_key_iszonekey(const dst_key_t *key);
isc_boolean_t
dst_key_isnullkey(const dst_key_t *key);
isc_result_t
dst_key_buildfilename(const dst_key_t *key, int type,
const char *directory, isc_buffer_t *out);
/*%<
* Generates the filename used by dst to store the specified key.
* If directory is NULL, the current directory is assumed.
*
* Requires:
*\li "key" is a valid key
*\li "type" is either DST_TYPE_PUBLIC, DST_TYPE_PRIVATE, or 0 for no suffix.
*\li "out" is a valid buffer
*
* Ensures:
*\li the file name will be written to "out", and the used pointer will
* be advanced.
*/
isc_result_t
dst_key_sigsize(const dst_key_t *key, unsigned int *n);
/*%<
* Computes the size of a signature generated by the given key.
*
* Requires:
*\li "key" is a valid key.
*\li "n" is not NULL
*
* Returns:
*\li #ISC_R_SUCCESS
*\li DST_R_UNSUPPORTEDALG
*
* Ensures:
*\li "n" stores the size of a generated signature
*/
isc_result_t
dst_key_secretsize(const dst_key_t *key, unsigned int *n);
/*%<
* Computes the size of a shared secret generated by the given key.
*
* Requires:
*\li "key" is a valid key.
*\li "n" is not NULL
*
* Returns:
*\li #ISC_R_SUCCESS
*\li DST_R_UNSUPPORTEDALG
*
* Ensures:
*\li "n" stores the size of a generated shared secret
*/
isc_uint16_t
dst_region_computeid(const isc_region_t *source, unsigned int alg);
/*%<
* Computes the key id of the key stored in the provided region with the
* given algorithm.
*
* Requires:
*\li "source" contains a valid, non-NULL region.
*
* Returns:
*\li the key id
*/
isc_uint16_t
dst_key_getbits(const dst_key_t *key);
/*
* Get the number of digest bits required (0 == MAX).
*
* Requires:
* "key" is a valid key.
*/
void
dst_key_setbits(dst_key_t *key, isc_uint16_t bits);
/*
* Set the number of digest bits required (0 == MAX).
*
* Requires:
* "key" is a valid key.
*/
ISC_LANG_ENDDECLS
#endif /* DST_DST_H */