#include "gnunet_common.h"
#include "gnunet_scheduler_lib.h"
+#include <gcrypt.h>
/**
};
+/**
+ * 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 ************* */
/**
struct GNUNET_CRYPTO_EcdsaPublicKey *result);
+/**
+ * Output the given MPI value to the given buffer in network
+ * byte order. The MPI @a val may not be negative.
+ *
+ * @param buf where to output to
+ * @param size number of bytes in @a buf
+ * @param val value to write to @a buf
+ */
+void
+GNUNET_CRYPTO_mpi_print_unsigned (void *buf,
+ size_t size,
+ gcry_mpi_t val);
+
+
+/**
+ * Convert data buffer into MPI value.
+ * The buffer is interpreted as network
+ * byte order, unsigned integer.
+ *
+ * @param result where to store MPI value (allocated)
+ * @param data raw data (GCRYMPI_FMT_USG)
+ * @param size number of bytes in @a data
+ */
+void
+GNUNET_CRYPTO_mpi_scan_unsigned (gcry_mpi_t *result,
+ const void *data,
+ 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