| /* 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 <openssl/base.h> |
| |
| #include <openssl/thread.h> |
| |
| #if defined(__cplusplus) |
| extern "C" { |
| #endif |
| |
| |
| // DH contains functions for performing Diffie-Hellman key agreement in |
| // multiplicative groups. |
| // |
| // This module is deprecated and retained for legacy reasons only. It is not |
| // considered a priority for performance or hardening work. Do not use it in |
| // new code. Use X25519 or ECDH with P-256 instead. |
| |
| |
| // Allocation and destruction. |
| |
| // DH_new returns a new, empty DH object or NULL on error. |
| OPENSSL_EXPORT DH *DH_new(void); |
| |
| // 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| and returns one. |
| OPENSSL_EXPORT int DH_up_ref(DH *dh); |
| |
| |
| // Properties. |
| |
| // DH_get0_pub_key returns |dh|'s public key. |
| OPENSSL_EXPORT const BIGNUM *DH_get0_pub_key(const DH *dh); |
| |
| // DH_get0_priv_key returns |dh|'s private key, or NULL if |dh| is a public key. |
| OPENSSL_EXPORT const BIGNUM *DH_get0_priv_key(const DH *dh); |
| |
| // DH_get0_p returns |dh|'s group modulus. |
| OPENSSL_EXPORT const BIGNUM *DH_get0_p(const DH *dh); |
| |
| // DH_get0_q returns the size of |dh|'s subgroup, or NULL if it is unset. |
| OPENSSL_EXPORT const BIGNUM *DH_get0_q(const DH *dh); |
| |
| // DH_get0_g returns |dh|'s group generator. |
| OPENSSL_EXPORT const BIGNUM *DH_get0_g(const DH *dh); |
| |
| // DH_get0_key sets |*out_pub_key| and |*out_priv_key|, if non-NULL, to |dh|'s |
| // public and private key, respectively. If |dh| is a public key, the private |
| // key will be set to NULL. |
| OPENSSL_EXPORT void DH_get0_key(const DH *dh, const BIGNUM **out_pub_key, |
| const BIGNUM **out_priv_key); |
| |
| // DH_set0_key sets |dh|'s public and private key to the specified values. If |
| // NULL, the field is left unchanged. On success, it takes ownership of each |
| // argument and returns one. Otherwise, it returns zero. |
| OPENSSL_EXPORT int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key); |
| |
| // DH_get0_pqg sets |*out_p|, |*out_q|, and |*out_g|, if non-NULL, to |dh|'s p, |
| // q, and g parameters, respectively. |
| OPENSSL_EXPORT void DH_get0_pqg(const DH *dh, const BIGNUM **out_p, |
| const BIGNUM **out_q, const BIGNUM **out_g); |
| |
| // DH_set0_pqg sets |dh|'s p, q, and g parameters to the specified values. If |
| // NULL, the field is left unchanged. On success, it takes ownership of each |
| // argument and returns one. Otherwise, it returns zero. |q| may be NULL, but |
| // |p| and |g| must either be specified or already configured on |dh|. |
| OPENSSL_EXPORT int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g); |
| |
| // DH_set_length sets the number of bits to use for the secret exponent when |
| // calling |DH_generate_key| on |dh| and returns one. If unset, |
| // |DH_generate_key| will use the bit length of p. |
| OPENSSL_EXPORT int DH_set_length(DH *dh, unsigned priv_length); |
| |
| |
| // Standard parameters. |
| |
| // BN_get_rfc3526_prime_1536 sets |*ret| to the 1536-bit MODP group from RFC |
| // 3526 and returns |ret|. If |ret| is NULL then a fresh |BIGNUM| is allocated |
| // and returned. It returns NULL on allocation failure. |
| OPENSSL_EXPORT BIGNUM *BN_get_rfc3526_prime_1536(BIGNUM *ret); |
| |
| // DH_get_rfc7919_2048 returns the group `ffdhe2048` from |
| // https://tools.ietf.org/html/rfc7919#appendix-A.1. It returns NULL if out |
| // of memory. |
| OPENSSL_EXPORT DH *DH_get_rfc7919_2048(void); |
| |
| |
| // 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_padded calculates the shared key between |dh| and |peers_key| |
| // and writes it as a big-endian integer into |out|, padded up to |DH_size| |
| // bytes. It returns the number of bytes written, which is always |DH_size|, or |
| // a negative number on error. |out| must have |DH_size| bytes of space. |
| // |
| // WARNING: this differs from the usual BoringSSL return-value convention. |
| // |
| // Note this function differs from |DH_compute_key| in that it preserves leading |
| // zeros in the secret. This function is the preferred variant. It matches PKCS |
| // #3 and avoids some side channel attacks. However, the two functions are not |
| // drop-in replacements for each other. Using a different variant than the |
| // application expects will result in sporadic key mismatches. |
| // |
| // Callers that expect a fixed-width secret should use this function over |
| // |DH_compute_key|. Callers that use either function should migrate to a modern |
| // primitive such as X25519 or ECDH with P-256 instead. |
| OPENSSL_EXPORT int DH_compute_key_padded(uint8_t *out, const BIGNUM *peers_key, |
| DH *dh); |
| |
| // DH_compute_key_hashed calculates the shared key between |dh| and |peers_key| |
| // and hashes it with the given |digest|. If the hash output is less than |
| // |max_out_len| bytes then it writes the hash output to |out| and sets |
| // |*out_len| to the number of bytes written. Otherwise it signals an error. It |
| // returns one on success or zero on error. |
| // |
| // NOTE: this follows the usual BoringSSL return-value convention, but that's |
| // different from |DH_compute_key| and |DH_compute_key_padded|. |
| OPENSSL_EXPORT int DH_compute_key_hashed(DH *dh, uint8_t *out, size_t *out_len, |
| size_t max_out_len, |
| const BIGNUM *peers_key, |
| const EVP_MD *digest); |
| |
| |
| // 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 0x1 |
| #define DH_CHECK_PUBKEY_TOO_LARGE 0x2 |
| #define DH_CHECK_PUBKEY_INVALID 0x4 |
| |
| // 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. |
| |
| // DH_parse_parameters decodes a DER-encoded DHParameter structure (PKCS #3) |
| // from |cbs| and advances |cbs|. It returns a newly-allocated |DH| or NULL on |
| // error. |
| OPENSSL_EXPORT DH *DH_parse_parameters(CBS *cbs); |
| |
| // DH_marshal_parameters marshals |dh| as a DER-encoded DHParameter structure |
| // (PKCS #3) and appends the result to |cbb|. It returns one on success and zero |
| // on error. |
| OPENSSL_EXPORT int DH_marshal_parameters(CBB *cbb, const DH *dh); |
| |
| |
| // Deprecated functions. |
| |
| // DH_generate_parameters behaves like |DH_generate_parameters_ex|, which is |
| // what you should use instead. It returns NULL on error, or a newly-allocated |
| // |DH| on success. This function is provided for compatibility only. |
| OPENSSL_EXPORT DH *DH_generate_parameters(int prime_len, int generator, |
| void (*callback)(int, int, void *), |
| void *cb_arg); |
| |
| // 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|. Note that, even if |*ret| is already non-NULL on |
| // entry, it will not be written to. Rather, a fresh |DH| is allocated and the |
| // previous one is freed. |
| // |
| // On successful exit, |*inp| is advanced past the DER structure. It |
| // returns the result or NULL on error. |
| // |
| // Use |DH_parse_parameters| instead. |
| 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. |
| // |
| // Use |DH_marshal_parameters| instead. |
| OPENSSL_EXPORT int i2d_DHparams(const DH *in, unsigned char **outp); |
| |
| // DH_compute_key behaves like |DH_compute_key_padded| but, contrary to PKCS #3, |
| // returns a variable-length shared key with leading zeros. It returns the |
| // number of bytes written, or a negative number on error. |out| must have |
| // |DH_size| bytes of space. |
| // |
| // WARNING: this differs from the usual BoringSSL return-value convention. |
| // |
| // Note this function's running time and memory access pattern leaks information |
| // about the shared secret. Particularly if |dh| is reused, this may result in |
| // side channel attacks such as https://raccoon-attack.com/. |
| // |
| // |DH_compute_key_padded| is the preferred variant and avoids the above |
| // attacks. However, the two functions are not drop-in replacements for each |
| // other. Using a different variant than the application expects will result in |
| // sporadic key mismatches. |
| // |
| // Callers that expect a fixed-width secret should use |DH_compute_key_padded| |
| // instead. Callers that use either function should migrate to a modern |
| // primitive such as X25519 or ECDH with P-256 instead. |
| OPENSSL_EXPORT int DH_compute_key(uint8_t *out, const BIGNUM *peers_key, |
| DH *dh); |
| |
| |
| struct dh_st { |
| 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; |
| }; |
| |
| |
| #if defined(__cplusplus) |
| } // extern C |
| |
| extern "C++" { |
| |
| BSSL_NAMESPACE_BEGIN |
| |
| BORINGSSL_MAKE_DELETER(DH, DH_free) |
| BORINGSSL_MAKE_UP_REF(DH, DH_up_ref) |
| |
| BSSL_NAMESPACE_END |
| |
| } // 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 |
| #define DH_R_DECODE_ERROR 104 |
| #define DH_R_ENCODE_ERROR 105 |
| |
| #endif // OPENSSL_HEADER_DH_H |