extending bandwidth tracker api to support notifications

[oweals/gnunet.git] / src / include / gnunet_crypto_lib.h

diff --git a/src/include/gnunet_crypto_lib.h b/src/include/gnunet_crypto_lib.h
index a5ee980926c821262856d569117e1efb3584ebab..d9c5e49e1e5bc31f1aca0ef7f8cba6c5a9ec745d 100644 (file)
--- a/src/include/gnunet_crypto_lib.h
+++ b/src/include/gnunet_crypto_lib.h
@@ -330,6 +330,58 @@ struct GNUNET_CRYPTO_AuthKey
 };
 
 
+/**
+ * Size of paillier plain texts and public keys.
+ * Private keys and ciphertexts are twice this size.
+ */
+#define GNUNET_CRYPTO_PAILLIER_BITS 2048
+
+
+/**
+ * Paillier public key.
+ */
+struct GNUNET_CRYPTO_PaillierPublicKey
+{
+  /**
+   * N value.
+   */
+  unsigned char n[GNUNET_CRYPTO_PAILLIER_BITS / 8];
+};
+
+
+/**
+ * Paillier public key.
+ */
+struct GNUNET_CRYPTO_PaillierPrivateKey
+{
+  /**
+   * Lambda-component of the private key.
+   */
+  unsigned char lambda[GNUNET_CRYPTO_PAILLIER_BITS / 8];
+  /**
+   * Mu-component of the private key.
+   */
+  unsigned char mu[GNUNET_CRYPTO_PAILLIER_BITS / 8];
+};
+
+
+/**
+ * Paillier ciphertext.
+ */
+struct GNUNET_CRYPTO_PaillierCiphertext
+{
+  /**
+   * guaranteed minimum number of homomorphic operations with this ciphertext
+   */
+  int32_t remaining_ops GNUNET_PACKED;
+  
+  /**
+   * The bits of the ciphertext.
+   */
+  unsigned char bits[GNUNET_CRYPTO_PAILLIER_BITS * 2 / 8];
+};
+
+
 /* **************** Functions and Macros ************* */
 
 /**
@@ -1262,6 +1314,75 @@ GNUNET_CRYPTO_mpi_scan_unsigned (gcry_mpi_t *result,
                                  size_t size);
 
 
+/**
+ * Create a freshly generated paillier public key.
+ *
+ * @param[out] public_key Where to store the public key?
+ * @param[out] private_key Where to store the private key?
+ */
+void
+GNUNET_CRYPTO_paillier_create (struct GNUNET_CRYPTO_PaillierPublicKey *public_key,
+                               struct GNUNET_CRYPTO_PaillierPrivateKey *private_key);
+
+
+/**
+ * Encrypt a plaintext with a paillier public key.
+ *
+ * @param public_key Public key to use.
+ * @param m Plaintext to encrypt.
+ * @param[out] ciphertext Encrytion of @a plaintext with @a public_key.
+ * @return guaranteed number of supported homomorphic operations
+ */
+int
+GNUNET_CRYPTO_paillier_encrypt (const struct GNUNET_CRYPTO_PaillierPublicKey *public_key,
+                                const gcry_mpi_t m,
+                                struct GNUNET_CRYPTO_PaillierCiphertext *ciphertext);
+
+
+/**
+ * Decrypt a paillier ciphertext with a private key.
+ *
+ * @param private_key Private key to use for decryption.
+ * @param public_key Public key to use for decryption.
+ * @param ciphertext Ciphertext to decrypt.
+ * @param[out] m Decryption of @a ciphertext with @private_key.
+ */
+void
+GNUNET_CRYPTO_paillier_decrypt (const struct GNUNET_CRYPTO_PaillierPrivateKey *private_key,
+                                const struct GNUNET_CRYPTO_PaillierPublicKey *public_key,
+                                const struct GNUNET_CRYPTO_PaillierCiphertext *ciphertext,
+                                gcry_mpi_t m);
+
+
+/**
+ * Compute a ciphertext that represents the sum of the plaintext in @a x1 and @a x2
+ *
+ * Note that this operation can only be done a finite number of times
+ * before an overflow occurs.
+ *
+ * @param public_key Public key to use for encryption.
+ * @param c1 Paillier cipher text.
+ * @param c2 Paillier cipher text.
+ * @param[out] result Result of the homomorphic operation.
+ * @return #GNUNET_OK if the result could be computed,
+ *         #GNUNET_SYSERR if no more homomorphic operations are remaining.
+ */
+int
+GNUNET_CRYPTO_paillier_hom_add (const struct GNUNET_CRYPTO_PaillierPublicKey *public_key,
+                                const struct GNUNET_CRYPTO_PaillierCiphertext *c1,
+                                const struct GNUNET_CRYPTO_PaillierCiphertext *c2,
+                                struct GNUNET_CRYPTO_PaillierCiphertext *result);
+
+
+/**
+ * Get the number of remaining supported homomorphic operations. 
+ *
+ * @param c Paillier cipher text.
+ * @return the number of remaining homomorphic operations
+ */
+int
+GNUNET_CRYPTO_paillier_hom_get_remaining (const struct GNUNET_CRYPTO_PaillierCiphertext *c);
+
 #if 0                           /* keep Emacsens' auto-indent happy */
 {
 #endif