* @author Gerd Knorr <kraxel@bytesex.org>
* @author Ioana Patrascu
* @author Tzvetan Horozov
+ * @author Jeffrey Burdges <burdges@gnunet.org>
*
* @defgroup crypto Crypto library: cryptographic operations
* Provides cryptographic primitives.
va_list argp);
+/**
+ * Deterministically generate a pseudo-random number uniformly from the
+ * integers modulo a libgcrypt mpi.
+ *
+ * @param[out] r MPI value set to the FDH
+ * @param n MPI to work modulo
+ * @param xts salt
+ * @param xts_len length of @a xts
+ * @param skm source key material
+ * @param skm_len length of @a skm
+ * @param ctx context string
+ */
+void
+GNUNET_CRYPTO_kdf_mod_mpi (gcry_mpi_t *r,
+ gcry_mpi_t n,
+ const void *xts, size_t xts_len,
+ const void *skm, size_t skm_len,
+ const char *ctx);
+
+
/**
* @ingroup hash
* @brief Derive key
struct GNUNET_CRYPTO_RsaPublicKey;
/**
- * Key used to blind a message
+ * Constant-size pre-secret for blinding key generation.
*/
-struct GNUNET_CRYPTO_rsa_BlindingKey;
+struct GNUNET_CRYPTO_RsaBlindingKeySecret
+{
+ /**
+ * Bits used to generate the blinding key. 256 bits
+ * of entropy is enough.
+ */
+ uint32_t pre_secret[8] GNUNET_PACKED;
+};
/**
* @brief an RSA signature
GNUNET_CRYPTO_rsa_public_key_dup (const struct GNUNET_CRYPTO_RsaPublicKey *key);
-/**
- * Create a blinding key
- *
- * @param len length of the key in bits (i.e. 2048)
- * @return the newly created blinding key
- */
-struct GNUNET_CRYPTO_rsa_BlindingKey *
-GNUNET_CRYPTO_rsa_blinding_key_create (unsigned int len);
-
-
-/**
- * Compare the values of two blinding keys.
- *
- * @param b1 one key
- * @param b2 the other key
- * @return 0 if the two are equal
- */
-int
-GNUNET_CRYPTO_rsa_blinding_key_cmp (struct GNUNET_CRYPTO_rsa_BlindingKey *b1,
- struct GNUNET_CRYPTO_rsa_BlindingKey *b2);
-
-
/**
* Compare the values of two signatures.
*
struct GNUNET_CRYPTO_RsaPublicKey *p2);
-/**
- * Destroy a blinding key
- *
- * @param bkey the blinding key to destroy
- */
-void
-GNUNET_CRYPTO_rsa_blinding_key_free (struct GNUNET_CRYPTO_rsa_BlindingKey *bkey);
-
-
-/**
- * Encode the blinding key in a format suitable for
- * storing it into a file.
- *
- * @param bkey the blinding key
- * @param[out] buffer set to a buffer with the encoded key
- * @return size of memory allocated in @a buffer
- */
-size_t
-GNUNET_CRYPTO_rsa_blinding_key_encode (const struct GNUNET_CRYPTO_rsa_BlindingKey *bkey,
- char **buffer);
-
-
-/**
- * Decode the blinding key from the data-format back
- * to the "normal", internal format.
- *
- * @param buf the buffer where the public key data is stored
- * @param len the length of the data in @a buf
- * @return NULL on error
- */
-struct GNUNET_CRYPTO_rsa_BlindingKey *
-GNUNET_CRYPTO_rsa_blinding_key_decode (const char *buf,
- size_t len);
-
-
/**
* Blinds the given message with the given blinding key
*
* @param hash hash of the message to sign
* @param bkey the blinding key
* @param pkey the public key of the signer
- * @param[out] buffer set to a buffer with the blinded message to be signed
- * @return number of bytes stored in @a buffer
+ * @param[out] buf set to a buffer with the blinded message to be signed
+ * @param[out] buf_size number of bytes stored in @a buf
+ * @return GNUNET_YES if successful, GNUNET_NO if RSA key is malicious
*/
-size_t
+int
GNUNET_CRYPTO_rsa_blind (const struct GNUNET_HashCode *hash,
- struct GNUNET_CRYPTO_rsa_BlindingKey *bkey,
+ const struct GNUNET_CRYPTO_RsaBlindingKeySecret *bks,
struct GNUNET_CRYPTO_RsaPublicKey *pkey,
- char **buffer);
+ char **buf, size_t *buf_size);
/**
*/
struct GNUNET_CRYPTO_RsaSignature *
GNUNET_CRYPTO_rsa_sign_blinded (const struct GNUNET_CRYPTO_RsaPrivateKey *key,
- const void *msg,
- size_t msg_len);
+ const void *msg, size_t msg_len);
/**
*
* @param key private key to use for the signing
* @param hash the hash of the message to sign
- * @return NULL on error, signature on success
+ * @return NULL on error, including a malicious RSA key, signature on success
*/
struct GNUNET_CRYPTO_RsaSignature *
GNUNET_CRYPTO_rsa_sign_fdh (const struct GNUNET_CRYPTO_RsaPrivateKey *key,
* #GNUNET_CRYPTO_rsa_blind().
*
* @param sig the signature made on the blinded signature purpose
- * @param bkey the blinding key used to blind the signature purpose
+ * @param bks the blinding key secret used to blind the signature purpose
* @param pkey the public key of the signer
- * @return unblinded signature on success, NULL on error
+ * @return unblinded signature on success, NULL if RSA key is bad or malicious.
*/
struct GNUNET_CRYPTO_RsaSignature *
GNUNET_CRYPTO_rsa_unblind (struct GNUNET_CRYPTO_RsaSignature *sig,
- struct GNUNET_CRYPTO_rsa_BlindingKey *bkey,
+ const struct GNUNET_CRYPTO_RsaBlindingKeySecret *bks,
struct GNUNET_CRYPTO_RsaPublicKey *pkey);
* @param hash the message to verify to match the @a sig
* @param sig signature that is being validated
* @param public_key public key of the signer
- * @returns #GNUNET_OK if ok, #GNUNET_SYSERR if invalid
+ * @returns #GNUNET_YES if ok, #GNUNET_NO if RSA key is malicious, #GNUNET_SYSERR if signature
*/
int
GNUNET_CRYPTO_rsa_verify (const struct GNUNET_HashCode *hash,