/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ #ifndef OPENSSL_HEADER_DH_H #define OPENSSL_HEADER_DH_H #include #include #include #include #if defined(__cplusplus) extern "C" { #endif /* DH contains functions for performing Diffie-Hellman key agreement in * multiplicative groups. */ /* Allocation and destruction. */ /* DH_new returns a new, empty DH object or NULL on error. */ OPENSSL_EXPORT DH *DH_new(void); /* DH_new_method acts the same as |DH_new| but takes an explicit |ENGINE|. */ OPENSSL_EXPORT DH *DH_new_method(const ENGINE *engine); /* DH_free decrements the reference count of |dh| and frees it if the reference * count drops to zero. */ OPENSSL_EXPORT void DH_free(DH *dh); /* DH_up_ref increments the reference count of |dh|. */ OPENSSL_EXPORT int DH_up_ref(DH *dh); /* Standard parameters. * * These functions return new DH objects with standard parameters configured * that use the given ENGINE, which may be NULL. They return NULL on allocation * failure. */ /* These parameters are taken from RFC 5114. */ OPENSSL_EXPORT DH *DH_get_1024_160(const ENGINE *engine); OPENSSL_EXPORT DH *DH_get_2048_224(const ENGINE *engine); OPENSSL_EXPORT DH *DH_get_2048_256(const ENGINE *engine); /* Parameter generation. */ #define DH_GENERATOR_2 2 #define DH_GENERATOR_5 5 /* DH_generate_parameters_ex generates a suitable Diffie-Hellman group with a * prime that is |prime_bits| long and stores it in |dh|. The generator of the * group will be |generator|, which should be |DH_GENERATOR_2| unless there's a * good reason to use a different value. The |cb| argument contains a callback * function that will be called during the generation. See the documentation in * |bn.h| about this. In addition to the callback invocations from |BN|, |cb| * will also be called with |event| equal to three when the generation is * complete. */ OPENSSL_EXPORT int DH_generate_parameters_ex(DH *dh, int prime_bits, int generator, BN_GENCB *cb); /* Diffie-Hellman operations. */ /* DH_generate_key generates a new, random, private key and stores it in * |dh|. It returns one on success and zero on error. */ OPENSSL_EXPORT int DH_generate_key(DH *dh); /* DH_compute_key calculates the shared key between |dh| and |peers_key| and * writes it as a big-endian integer into |out|, which must have |DH_size| * bytes of space. It returns the number of bytes written, or a negative number * on error. */ OPENSSL_EXPORT int DH_compute_key(uint8_t *out, const BIGNUM *peers_key, DH *dh); /* Utility functions. */ /* DH_size returns the number of bytes in the DH group's prime. */ OPENSSL_EXPORT int DH_size(const DH *dh); /* DH_num_bits returns the minimum number of bits needed to represent the * absolute value of the DH group's prime. */ OPENSSL_EXPORT unsigned DH_num_bits(const DH *dh); #define DH_CHECK_P_NOT_PRIME 0x01 #define DH_CHECK_P_NOT_SAFE_PRIME 0x02 #define DH_CHECK_UNABLE_TO_CHECK_GENERATOR 0x04 #define DH_CHECK_NOT_SUITABLE_GENERATOR 0x08 #define DH_CHECK_Q_NOT_PRIME 0x10 #define DH_CHECK_INVALID_Q_VALUE 0x20 #define DH_CHECK_INVALID_J_VALUE 0x40 /* These are compatibility defines. */ #define DH_NOT_SUITABLE_GENERATOR DH_CHECK_NOT_SUITABLE_GENERATOR #define DH_UNABLE_TO_CHECK_GENERATOR DH_CHECK_UNABLE_TO_CHECK_GENERATOR /* DH_check checks the suitability of |dh| as a Diffie-Hellman group. and sets * |DH_CHECK_*| flags in |*out_flags| if it finds any errors. It returns one if * |*out_flags| was successfully set and zero on error. * * Note: these checks may be quite computationally expensive. */ OPENSSL_EXPORT int DH_check(const DH *dh, int *out_flags); #define DH_CHECK_PUBKEY_TOO_SMALL 1 #define DH_CHECK_PUBKEY_TOO_LARGE 2 /* DH_check_pub_key checks the suitability of |pub_key| as a public key for the * DH group in |dh| and sets |DH_CHECK_PUBKEY_*| flags in |*out_flags| if it * finds any errors. It returns one if |*out_flags| was successfully set and * zero on error. */ OPENSSL_EXPORT int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *out_flags); /* DHparams_dup allocates a fresh |DH| and copies the parameters from |dh| into * it. It returns the new |DH| or NULL on error. */ OPENSSL_EXPORT DH *DHparams_dup(const DH *dh); /* ASN.1 functions. */ /* d2i_DHparams parses an ASN.1, DER encoded Diffie-Hellman parameters * structure from |len| bytes at |*inp|. If |ret| is not NULL then, on exit, a * pointer to the result is in |*ret|. If |*ret| is already non-NULL on entry * then the result is written directly into |*ret|, otherwise a fresh |DH| is * allocated. On successful exit, |*inp| is advanced past the DER structure. It * returns the result or NULL on error. */ OPENSSL_EXPORT DH *d2i_DHparams(DH **ret, const unsigned char **inp, long len); /* i2d_DHparams marshals |in| to an ASN.1, DER structure. If |outp| is not NULL * then the result is written to |*outp| and |*outp| is advanced just past the * output. It returns the number of bytes in the result, whether written or * not, or a negative value on error. */ OPENSSL_EXPORT int i2d_DHparams(const DH *in, unsigned char **outp); /* ex_data functions. * * See |ex_data.h| for details. */ OPENSSL_EXPORT int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func); OPENSSL_EXPORT int DH_set_ex_data(DH *d, int idx, void *arg); OPENSSL_EXPORT void *DH_get_ex_data(DH *d, int idx); /* dh_method contains function pointers to override the implementation of DH. * See |engine.h| for details. */ struct dh_method { struct openssl_method_common_st common; /* app_data is an opaque pointer for the method to use. */ void *app_data; /* init is called just before the return of |DH_new_method|. It returns one * on success or zero on error. */ int (*init)(DH *dh); /* finish is called before |dh| is destructed. */ void (*finish)(DH *dh); /* generate_parameters is called by |DH_generate_parameters_ex|. */ int (*generate_parameters)(DH *dh, int prime_bits, int generator, BN_GENCB *cb); /* generate_parameters is called by |DH_generate_key|. */ int (*generate_key)(DH *dh); /* compute_key is called by |DH_compute_key|. */ int (*compute_key)(DH *dh, uint8_t *out, const BIGNUM *pub_key); }; struct dh_st { DH_METHOD *meth; BIGNUM *p; BIGNUM *g; BIGNUM *pub_key; /* g^x mod p */ BIGNUM *priv_key; /* x */ /* priv_length contains the length, in bits, of the private value. If zero, * the private value will be the same length as |p|. */ unsigned priv_length; CRYPTO_MUTEX method_mont_p_lock; BN_MONT_CTX *method_mont_p; /* Place holders if we want to do X9.42 DH */ BIGNUM *q; BIGNUM *j; unsigned char *seed; int seedlen; BIGNUM *counter; int flags; CRYPTO_refcount_t references; CRYPTO_EX_DATA ex_data; }; #if defined(__cplusplus) } /* extern C */ #endif #define DH_R_BAD_GENERATOR 100 #define DH_R_INVALID_PUBKEY 101 #define DH_R_MODULUS_TOO_LARGE 102 #define DH_R_NO_PRIVATE_VALUE 103 #endif /* OPENSSL_HEADER_DH_H */