src/common/crypto_curve25519.h

   1 /* Copyright (c) 2012-2013, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 #ifndef TOR_CRYPTO_CURVE25519_H
   5 #define TOR_CRYPTO_CURVE25519_H
   6
   7 #include "testsupport.h"
   8 #include "torint.h"
   9
  10 /** Length of a curve25519 public key when encoded. */
  11 #define CURVE25519_PUBKEY_LEN 32
  12 /** Length of a curve25519 secret key when encoded. */
  13 #define CURVE25519_SECKEY_LEN 32
  14 /** Length of the result of a curve25519 handshake. */
  15 #define CURVE25519_OUTPUT_LEN 32
  16
  17 /** Wrapper type for a curve25519 public key */
  18 typedef struct curve25519_public_key_t {
  19   uint8_t public_key[CURVE25519_PUBKEY_LEN];
  20 } curve25519_public_key_t;
  21
  22 /** Wrapper type for a curve25519 secret key */
  23 typedef struct curve25519_secret_key_t {
  24   uint8_t secret_key[CURVE25519_SECKEY_LEN];
  25 } curve25519_secret_key_t;
  26
  27 /** A paired public and private key for curve25519. **/
  28 typedef struct curve25519_keypair_t {
  29   curve25519_public_key_t pubkey;
  30   curve25519_secret_key_t seckey;
  31 } curve25519_keypair_t;
  32
  33 #ifdef CURVE25519_ENABLED
  34 /* These functions require that we actually know how to use curve25519 keys.
  35  * The other data structures and functions in this header let us parse them,
  36  * store them, and move them around.
  37  */
  38
  39 int curve25519_public_key_is_ok(const curve25519_public_key_t *);
  40
  41 int curve25519_secret_key_generate(curve25519_secret_key_t *key_out,
  42                                    int extra_strong);
  43 void curve25519_public_key_generate(curve25519_public_key_t *key_out,
  44                                     const curve25519_secret_key_t *seckey);
  45 int curve25519_keypair_generate(curve25519_keypair_t *keypair_out,
  46                                 int extra_strong);
  47
  48 void curve25519_handshake(uint8_t *output,
  49                           const curve25519_secret_key_t *,
  50                           const curve25519_public_key_t *);
  51
  52 int curve25519_keypair_write_to_file(const curve25519_keypair_t *keypair,
  53                                      const char *fname,
  54                                      const char *tag);
  55
  56 int curve25519_keypair_read_from_file(curve25519_keypair_t *keypair_out,
  57                                       char **tag_out,
  58                                       const char *fname);
  59
  60 #ifdef CRYPTO_CURVE25519_PRIVATE
  61 STATIC int curve25519_impl(uint8_t *output, const uint8_t *secret,
  62                            const uint8_t *basepoint);
  63 #endif
  64 #endif
  65
  66 #define CURVE25519_BASE64_PADDED_LEN 44
  67
  68 int curve25519_public_from_base64(curve25519_public_key_t *pkey,
  69                                   const char *input);
  70 int curve25519_public_to_base64(char *output,
  71                                 const curve25519_public_key_t *pkey);
  72
  73 #endif
  74