src/lib/crypt_ops/crypto_curve25519.h

   1 /* Copyright (c) 2012-2021, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 /**
   5  * \file crypto_curve25519.h
   6  * \brief Header for crypto_curve25519.c
   7  **/
   8
   9 #ifndef TOR_CRYPTO_CURVE25519_H
  10 #define TOR_CRYPTO_CURVE25519_H
  11
  12 #include <stdbool.h>
  13 #include "lib/testsupport/testsupport.h"
  14 #include "lib/cc/torint.h"
  15 #include "lib/crypt_ops/crypto_digest.h"
  16 #include "lib/crypt_ops/crypto_openssl_mgt.h"
  17 #include "lib/defs/x25519_sizes.h"
  18
  19 /** Wrapper type for a curve25519 public key.
  20  *
  21  *  (We define a separate type for these to make it less likely that we'll
  22  *  mistake them for secret keys.)
  23  * */
  24 typedef struct curve25519_public_key_t {
  25   uint8_t public_key[CURVE25519_PUBKEY_LEN];
  26 } curve25519_public_key_t;
  27
  28 /** Wrapper type for a curve25519 secret key
  29  *
  30  * (We define a separate type for these to make it less likely that we'll
  31  * mistake them for public keys.)
  32  **/
  33 typedef struct curve25519_secret_key_t {
  34   uint8_t secret_key[CURVE25519_SECKEY_LEN];
  35 } curve25519_secret_key_t;
  36
  37 /** A paired public and private key for curve25519. **/
  38 typedef struct curve25519_keypair_t {
  39   curve25519_public_key_t pubkey;
  40   curve25519_secret_key_t seckey;
  41 } curve25519_keypair_t;
  42
  43 /* These functions require that we actually know how to use curve25519 keys.
  44  * The other data structures and functions in this header let us parse them,
  45  * store them, and move them around.
  46  */
  47
  48 int curve25519_public_key_is_ok(const curve25519_public_key_t *);
  49
  50 int curve25519_secret_key_generate(curve25519_secret_key_t *key_out,
  51                                    int extra_strong);
  52 void curve25519_public_key_generate(curve25519_public_key_t *key_out,
  53                                     const curve25519_secret_key_t *seckey);
  54 int curve25519_keypair_generate(curve25519_keypair_t *keypair_out,
  55                                 int extra_strong);
  56
  57 void curve25519_handshake(uint8_t *output,
  58                           const curve25519_secret_key_t *,
  59                           const curve25519_public_key_t *);
  60
  61 int curve25519_keypair_write_to_file(const curve25519_keypair_t *keypair,
  62                                      const char *fname,
  63                                      const char *tag);
  64
  65 int curve25519_keypair_read_from_file(curve25519_keypair_t *keypair_out,
  66                                       char **tag_out,
  67                                       const char *fname);
  68
  69 int curve25519_rand_seckey_bytes(uint8_t *out, int extra_strong);
  70
  71 #ifdef CRYPTO_CURVE25519_PRIVATE
  72 STATIC int curve25519_impl(uint8_t *output, const uint8_t *secret,
  73                            const uint8_t *basepoint);
  74
  75 STATIC int curve25519_basepoint_impl(uint8_t *output, const uint8_t *secret);
  76 #endif /* defined(CRYPTO_CURVE25519_PRIVATE) */
  77
  78 int curve25519_public_from_base64(curve25519_public_key_t *pkey,
  79                                   const char *input);
  80 void curve25519_public_to_base64(char *output,
  81                                  const curve25519_public_key_t *pkey,
  82                                  bool pad);
  83
  84 void curve25519_set_impl_params(int use_ed);
  85 void curve25519_init(void);
  86
  87 #endif /* !defined(TOR_CRYPTO_CURVE25519_H) */