--- /dev/null
+/*
+ * Copyright (c) 2007-2008,2010,2012-2013 Apple Inc. All Rights Reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+/*!
+ @header SecDH
+ The functions provided in SecDH.h implement the crypto required
+ for a Diffie-Hellman key exchange.
+*/
+
+#ifndef _SECURITY_SECDH_H_
+#define _SECURITY_SECDH_H_
+
+#include <Security/SecBase.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct OpaqueSecDHContext *SecDHContext;
+
+/*!
+ @function SecDHCreate
+ @abstract Return a newly allocated SecDHContext object.
+ @param g generator (2 or 5)
+ @param p prime as a big-endian unsigned byte array
+ @param p_len length of p, in bytes
+ @param l (optional) minimum length of private key in bits, or 0 for default
+ @param recip (optional) reciprocal of p as a big-endian unsigned byte array
+ @param recip_len length of recip, in bytes
+ @param dh (output) pointer to a SecDHContext
+ @discussion The recip and recip_len parameters are constant for a given p.
+ They are optional, although providing them improves performance.
+ @result On success, a newly allocated SecDHContext is returned in dh and
+ errSecSuccess is returned. On failure, NULL is returned in dh and an OSStatus error
+ code is returned.
+ The caller should call SecDHDestroy once the returned context is no longer
+ needed.
+ */
+OSStatus SecDHCreate(uint32_t g, const uint8_t *p, size_t p_len, uint32_t l,
+ const uint8_t *recip, size_t recip_len, SecDHContext *dh);
+
+/*!
+ @function SecDHCreateFromParameters
+ @param params A DER-encoded ASN.1 parameter object, as per PKCS3, containing
+ Diffie-Hellman key parameters
+ @param params_len Length of params, in bytes
+ @param dh (output) A pointer to a SecDHContext
+ @result On success, a newly allocated SecDHContext is returned in dh and
+ errSecSuccess is returned. On failure, NULL is returned in dh and an OSStatus error
+ code is returned.
+ The caller should call SecDHDestroy once the returned context is no longer
+ needed.
+ */
+OSStatus SecDHCreateFromParameters(const uint8_t *params, size_t params_len,
+ SecDHContext *dh);
+
+/*!
+ @function SecDHCreateFromAlgorithmId
+ @param alg A DER-encoded ASN.1 Algorithm Identifier object, as per PKCS1,
+ containing DH parameters.
+ @param alg_len Length of alg, in bytes
+ @param dh (output) A pointer to a SecDHContext
+ @result On success, a newly allocated SecDHContext is returned in dh and
+ errSecSuccess is returned. On failure, NULL is returned in dh and an OSStatus error
+ code is returned.
+ The caller should call SecDHDestroy once the returned context is no longer
+ needed.
+ */
+OSStatus SecDHCreateFromAlgorithmId(const uint8_t *alg, size_t alg_len,
+ SecDHContext *dh);
+
+/*!
+ @function SecDHGetMaxKeyLength
+ @abstract Return the maximum length in bytes of the pub_key returned by
+ SecDHGenerateKeypair().
+ @param dh A context created by one of the SecDHCreate functions
+ @discussion The value returned by this function is also the largest number
+ of bytes returned by SecDHComputeKey(). If a caller used the
+ SecDHCreate() function to create the SecDHContext passed to this function,
+ the value returned will be less than or equal to the p_len parameter
+ passed to SecDHCreate().
+ @result Return maximum length, in bytes, of keys returned by the passed-in
+ SecDHContext.
+ */
+size_t SecDHGetMaxKeyLength(SecDHContext dh);
+
+/*!
+ @function SecDHGenerateKeypair
+ @abstract Generate a Diffie-Hellman private/public key pair and return
+ the public key as an unsigned big-endian byte array.
+ @param dh A context created by one of the SecDHCreate functions
+ @param pub_key On return, the public key to be shared with the other party.
+ @params pub_key_len On input, the number of bytes available in pub_key;
+ on output, the number of bytes actually in pub_key.
+ @discussion Reusing a SecDHContext for multiple SecDHGenerateKeypair()
+ invocations is permitted.
+ @result errSecSuccess on success, or an OSStatus error code on failure.
+ */
+OSStatus SecDHGenerateKeypair(SecDHContext dh, uint8_t *pub_key,
+ size_t *pub_key_len);
+
+/*!
+ @function SecDHComputeKey
+ @abstract Given a SecDHContext and the other party's public key,
+ compute the shared secret.
+ @param dh A context created by one of the SecDHCreate functions, on which
+ SecDHGenerateKeypair() has been invoked first.
+ @param pub_key The other party's public key, as an unsigned big-endian byte
+ array.
+ @params pub_key_len The length of pub_key, in bytes
+ @param computed_key A pointer to a byte array in which the computed key
+ is returned.
+ @param computed_key_len On input, contains the number of
+ bytes requested to be returned in computed_key; on output, contains
+ the number of bytes returned in computed_key.
+ This will only be less than the requested number of bytes if the number
+ of bytes requested is larger than the number of bytes output by the
+ compute-key operation.
+ @discussion If *computed_key_len is less than the size of the actual
+ computed key, only the first *computed_key_len bytes will be returned.
+ No leading zero bytes will be returned, and the computed_key is returned
+ as an unsigned big-endian byte array.
+ @result errSecSuccess on success, or an OSStatus error code on failure.
+ */
+OSStatus SecDHComputeKey(SecDHContext dh,
+ const uint8_t *pub_key, size_t pub_key_len,
+ uint8_t *computed_key, size_t *computed_key_len);
+
+/*!
+ @function SecDHDestroy
+ @abstract Destroy a SecDHContext created with one of the SecDHCreate functions.
+ @param dh A context created by one of the SecDHCreate functions
+ */
+void SecDHDestroy(SecDHContext dh);
+
+
+/*!
+ @function SecDHEncodeParams
+ @abstract Encode parameters in a PKCS#3 blob
+ */
+OSStatus SecDHEncodeParams(CFDataRef g, CFDataRef p,
+ CFDataRef l, CFDataRef recip,
+ CFDataRef *params);
+
+/*!
+ @function SecDHDecodeParams
+ @abstract Decode parameters in a PKCS#3 blob
+ */
+OSStatus SecDHDecodeParams(CFDataRef *g, CFDataRef *p,
+ CFDataRef *l, CFDataRef *r,
+ CFDataRef params);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SECURITY_SECDH_H_ */
projects / apple / security.git / blobdiff