GNUnet  0.17.5
Macros | Functions
crypto_ecc.c File Reference

public key cryptography (ECC) with libgcrypt More...

#include "platform.h"
#include <gcrypt.h>
#include <sodium.h>
#include "gnunet_crypto_lib.h"
#include "gnunet_strings_lib.h"
#include "benchmark.h"
Include dependency graph for crypto_ecc.c:

Go to the source code of this file.

Macros

#define EXTRA_CHECKS   0
 
#define CURVE   "Ed25519"
 IMPLEMENTATION NOTICE: More...
 
#define LOG(kind, ...)   GNUNET_log_from (kind, "util-crypto-ecc", __VA_ARGS__)
 
#define LOG_STRERROR(kind, syscall)    GNUNET_log_from_strerror (kind, "util-crypto-ecc", syscall)
 
#define LOG_STRERROR_FILE(kind, syscall, filename)    GNUNET_log_from_strerror_file (kind, "util-crypto-ecc", syscall, filename)
 
#define LOG_GCRY(level, cmd, rc)
 Log an error message at log-level 'level' that indicates a failure of the command 'cmd' with the message given by gcry_strerror(rc). More...
 

Functions

static int key_from_sexp (gcry_mpi_t *array, gcry_sexp_t sexp, const char *topname, const char *elems)
 Extract values from an S-expression. More...
 
static gcry_sexp_t decode_private_ecdsa_key (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv)
 Convert the given private key from the network format to the S-expression that can be used by libgcrypt. More...
 
void GNUNET_CRYPTO_ecdsa_key_get_public (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv, struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
 Extract the public key for the given private key. More...
 
void GNUNET_CRYPTO_eddsa_key_get_public (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv, struct GNUNET_CRYPTO_EddsaPublicKey *pub)
 Extract the public key for the given private key. More...
 
void GNUNET_CRYPTO_ecdhe_key_get_public (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv, struct GNUNET_CRYPTO_EcdhePublicKey *pub)
 Extract the public key for the given private key. More...
 
char * GNUNET_CRYPTO_ecdsa_public_key_to_string (const struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
 Convert a public key to a string. More...
 
char * GNUNET_CRYPTO_eddsa_public_key_to_string (const struct GNUNET_CRYPTO_EddsaPublicKey *pub)
 Convert a public key to a string. More...
 
char * GNUNET_CRYPTO_eddsa_private_key_to_string (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv)
 Convert a private key to a string. More...
 
char * GNUNET_CRYPTO_ecdsa_private_key_to_string (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv)
 Convert a private key to a string. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_ecdsa_public_key_from_string (const char *enc, size_t enclen, struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
 Convert a string representing a public key to a public key. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_eddsa_public_key_from_string (const char *enc, size_t enclen, struct GNUNET_CRYPTO_EddsaPublicKey *pub)
 Convert a string representing a public key to a public key. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_eddsa_private_key_from_string (const char *enc, size_t enclen, struct GNUNET_CRYPTO_EddsaPrivateKey *priv)
 Convert a string representing a private key to a private key. More...
 
void GNUNET_CRYPTO_ecdhe_key_clear (struct GNUNET_CRYPTO_EcdhePrivateKey *pk)
 Clear memory that was used to store a private key. More...
 
void GNUNET_CRYPTO_ecdsa_key_clear (struct GNUNET_CRYPTO_EcdsaPrivateKey *pk)
 Clear memory that was used to store a private key. More...
 
void GNUNET_CRYPTO_eddsa_key_clear (struct GNUNET_CRYPTO_EddsaPrivateKey *pk)
 Clear memory that was used to store a private key. More...
 
void GNUNET_CRYPTO_ecdhe_key_create (struct GNUNET_CRYPTO_EcdhePrivateKey *pk)
 Create a new private key. More...
 
void GNUNET_CRYPTO_ecdsa_key_create (struct GNUNET_CRYPTO_EcdsaPrivateKey *pk)
 Create a new private key. More...
 
void GNUNET_CRYPTO_eddsa_key_create (struct GNUNET_CRYPTO_EddsaPrivateKey *pk)
 Create a new private key. More...
 
const struct GNUNET_CRYPTO_EcdsaPrivateKeyGNUNET_CRYPTO_ecdsa_key_get_anonymous ()
 Get the shared private key we use for anonymous users. More...
 
static gcry_sexp_t data_to_ecdsa_value (const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose)
 Convert the data specified in the given purpose argument to an S-expression suitable for signature operations. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_ecdsa_sign_ (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv, const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose, struct GNUNET_CRYPTO_EcdsaSignature *sig)
 ECDSA Sign a given block. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_eddsa_sign_raw (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv, void *data, size_t size, struct GNUNET_CRYPTO_EddsaSignature *sig)
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_eddsa_sign_ (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv, const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose, struct GNUNET_CRYPTO_EddsaSignature *sig)
 EdDSA sign a given block. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_ecdsa_verify_ (uint32_t purpose, const struct GNUNET_CRYPTO_EccSignaturePurpose *validate, const struct GNUNET_CRYPTO_EcdsaSignature *sig, const struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
 Verify ECDSA signature. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_eddsa_verify_ (uint32_t purpose, const struct GNUNET_CRYPTO_EccSignaturePurpose *validate, const struct GNUNET_CRYPTO_EddsaSignature *sig, const struct GNUNET_CRYPTO_EddsaPublicKey *pub)
 Verify EdDSA signature. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_ecc_ecdh (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv, const struct GNUNET_CRYPTO_EcdhePublicKey *pub, struct GNUNET_HashCode *key_material)
 Derive key material from a public and a private ECC key. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_eddsa_ecdh (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv, const struct GNUNET_CRYPTO_EcdhePublicKey *pub, struct GNUNET_HashCode *key_material)
 Derive key material from a ECDH public key and a private EdDSA key. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_ecdsa_ecdh (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv, const struct GNUNET_CRYPTO_EcdhePublicKey *pub, struct GNUNET_HashCode *key_material)
 Derive key material from a ECDH public key and a private ECDSA key. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_ecdh_eddsa (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv, const struct GNUNET_CRYPTO_EddsaPublicKey *pub, struct GNUNET_HashCode *key_material)
 Derive key material from a EdDSA public key and a private ECDH key. More...
 
enum GNUNET_GenericReturnValue GNUNET_CRYPTO_ecdh_ecdsa (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv, const struct GNUNET_CRYPTO_EcdsaPublicKey *pub, struct GNUNET_HashCode *key_material)
 Derive key material from a EcDSA public key and a private ECDH key. More...
 

Detailed Description

public key cryptography (ECC) with libgcrypt

Author
Christian Grothoff
Florian Dold

Definition in file crypto_ecc.c.

Macro Definition Documentation

◆ EXTRA_CHECKS

#define EXTRA_CHECKS   0

Definition at line 34 of file crypto_ecc.c.

◆ CURVE

#define CURVE   "Ed25519"

IMPLEMENTATION NOTICE:

ECDSA: We use a non-standard curve for ECDSA: Ed25519. For performance reasons, we use cryptographic operations from libsodium wherever we can get away with it, even though libsodium itself does not support ECDSA. This is why the sign and verifiy functionality from libgcrypt is required and used.

EdDSA: We use a standard EdDSA construction. (We still use libgcrypt for hashing and RNG, but not EC)

ECDHE: For both EdDSA and ECDSA keys, we use libsodium for ECDHE due to performance benefits over libgcrypt. Name of the curve we are using. Note that we have hard-coded structs that use 256 bits, so using a bigger curve will require changes that break stuff badly. The name of the curve given here must be agreed by all peers and be supported by libgcrypt.

Definition at line 59 of file crypto_ecc.c.

◆ LOG

#define LOG (   kind,
  ... 
)    GNUNET_log_from (kind, "util-crypto-ecc", __VA_ARGS__)

Definition at line 61 of file crypto_ecc.c.

◆ LOG_STRERROR

#define LOG_STRERROR (   kind,
  syscall 
)     GNUNET_log_from_strerror (kind, "util-crypto-ecc", syscall)

Definition at line 63 of file crypto_ecc.c.

◆ LOG_STRERROR_FILE

#define LOG_STRERROR_FILE (   kind,
  syscall,
  filename 
)     GNUNET_log_from_strerror_file (kind, "util-crypto-ecc", syscall, filename)

Definition at line 66 of file crypto_ecc.c.

◆ LOG_GCRY

#define LOG_GCRY (   level,
  cmd,
  rc 
)
Value:
do \
{ \
LOG (level, \
_ ("`%s' failed at %s:%d with error: %s\n"), \
cmd, \
__FILE__, \
__LINE__, \
gcry_strerror (rc)); \
} while (0)
#define _(String)
GNU gettext support macro.
Definition: platform.h:177

Log an error message at log-level 'level' that indicates a failure of the command 'cmd' with the message given by gcry_strerror(rc).

Definition at line 74 of file crypto_ecc.c.

Function Documentation

◆ key_from_sexp()

static int key_from_sexp ( gcry_mpi_t *  array,
gcry_sexp_t  sexp,
const char *  topname,
const char *  elems 
)
static

Extract values from an S-expression.

Parameters
arraywhere to store the result(s)
sexpS-expression to parse
topnametop-level name in the S-expression that is of interest
elemsnames of the elements to extract
Returns
0 on success

Definition at line 96 of file crypto_ecc.c.

100 {
101  gcry_sexp_t list;
102  gcry_sexp_t l2;
103  unsigned int idx;
104 
105  list = gcry_sexp_find_token (sexp, topname, 0);
106  if (! list)
107  return 1;
108  l2 = gcry_sexp_cadr (list);
109  gcry_sexp_release (list);
110  list = l2;
111  if (! list)
112  return 2;
113 
114  idx = 0;
115  for (const char *s = elems; *s; s++, idx++)
116  {
117  l2 = gcry_sexp_find_token (list, s, 1);
118  if (! l2)
119  {
120  for (unsigned int i = 0; i < idx; i++)
121  {
122  gcry_free (array[i]);
123  array[i] = NULL;
124  }
125  gcry_sexp_release (list);
126  return 3; /* required parameter not found */
127  }
128  array[idx] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG);
129  gcry_sexp_release (l2);
130  if (! array[idx])
131  {
132  for (unsigned int i = 0; i < idx; i++)
133  {
134  gcry_free (array[i]);
135  array[i] = NULL;
136  }
137  gcry_sexp_release (list);
138  return 4; /* required parameter is invalid */
139  }
140  }
141  gcry_sexp_release (list);
142  return 0;
143 }
static int list
Set if we should print a list of currently running services.
Definition: gnunet-arm.c:69

References list.

◆ decode_private_ecdsa_key()

static gcry_sexp_t decode_private_ecdsa_key ( const struct GNUNET_CRYPTO_EcdsaPrivateKey priv)
static

Convert the given private key from the network format to the S-expression that can be used by libgcrypt.

Parameters
privprivate key to decode
Returns
NULL on error

Definition at line 154 of file crypto_ecc.c.

155 {
156  gcry_sexp_t result;
157  int rc;
158  uint8_t d[32];
159 
160  for (size_t i = 0; i<32; i++)
161  d[i] = priv->d[31 - i];
162 
163  rc = gcry_sexp_build (&result,
164  NULL,
165  "(private-key(ecc(curve \"" CURVE "\")"
166  "(d %b)))",
167  32,
168  d);
169  if (0 != rc)
170  {
171  LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
172  GNUNET_assert (0);
173  }
174 #if EXTRA_CHECKS
175  if (0 != (rc = gcry_pk_testkey (result)))
176  {
177  LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_pk_testkey", rc);
178  GNUNET_assert (0);
179  }
180 #endif
181  return result;
182 }
#define CURVE
IMPLEMENTATION NOTICE:
Definition: crypto_ecc.c:59
#define LOG_GCRY(level, cmd, rc)
Log an error message at log-level 'level' that indicates a failure of the command 'cmd' with the mess...
Definition: crypto_ecc.c:74
static int result
Global testing status.
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
@ GNUNET_ERROR_TYPE_ERROR
unsigned char d[256/8]
d is a value mod n, where n has at most 256 bits.

References CURVE, GNUNET_CRYPTO_EcdsaPrivateKey::d, GNUNET_assert, GNUNET_ERROR_TYPE_ERROR, LOG_GCRY, and result.

◆ data_to_ecdsa_value()

static gcry_sexp_t data_to_ecdsa_value ( const struct GNUNET_CRYPTO_EccSignaturePurpose purpose)
static

Convert the data specified in the given purpose argument to an S-expression suitable for signature operations.

Parameters
purposedata to convert
Returns
converted s-expression

Definition at line 512 of file crypto_ecc.c.

513 {
514  gcry_sexp_t data;
515  int rc;
516 
517 /* See #5398 */
518 #if 1
519  struct GNUNET_HashCode hc;
520 
521  GNUNET_CRYPTO_hash (purpose, ntohl (purpose->size), &hc);
522  if (0 != (rc = gcry_sexp_build (&data,
523  NULL,
524  "(data(flags rfc6979)(hash %s %b))",
525  "sha512",
526  (int) sizeof(hc),
527  &hc)))
528  {
529  LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
530  return NULL;
531  }
532 #else
533  if (0 != (rc = gcry_sexp_build (&data,
534  NULL,
535  "(data(flags rfc6979)(hash %s %b))",
536  "sha512",
537  ntohl (purpose->size),
538  purpose)))
539  {
540  LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
541  return NULL;
542  }
543 #endif
544  return data;
545 }
uint32_t data
The data value.
void GNUNET_CRYPTO_hash(const void *block, size_t size, struct GNUNET_HashCode *ret)
Compute hash of a given block.
Definition: crypto_hash.c:41
uint32_t size
How many bytes does this signature sign? (including this purpose header); in network byte order (!...
A 512-bit hashcode.