/*
This file is part of GNUnet.
- (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2012 Christian Grothoff (and other contributing authors)
+ (C) 2001-2013 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
* @author Gerd Knorr <kraxel@bytesex.org>
* @author Ioana Patrascu
* @author Tzvetan Horozov
+ *
+ * @defgroup crypto Cryptographic operations
+ * @defgroup hash Hashing and operations on hashes
*/
#ifndef GNUNET_CRYPTO_LIB_H
#endif
#endif
+/**
+ * @brief A 512-bit hashcode
+ */
+struct GNUNET_HashCode;
+
+/**
+ * The identity of the host (wraps the signing key of the peer).
+ */
+struct GNUNET_PeerIdentity;
+
#include "gnunet_common.h"
#include "gnunet_scheduler_lib.h"
+#include <gcrypt.h>
+
+
+/**
+ * @brief A 512-bit hashcode
+ */
+struct GNUNET_HashCode
+{
+ uint32_t bits[512 / 8 / sizeof (uint32_t)]; /* = 16 */
+};
/**
/**
- * Desired quality level for cryptographic operations.
+ * Desired quality level for random numbers.
+ * @ingroup crypto
*/
enum GNUNET_CRYPTO_Quality
{
/**
* No good quality of the operation is needed (i.e.,
* random numbers can be pseudo-random).
+ * @ingroup crypto
*/
GNUNET_CRYPTO_QUALITY_WEAK,
/**
* High-quality operations are desired.
+ * @ingroup crypto
*/
GNUNET_CRYPTO_QUALITY_STRONG,
/**
* Randomness for IVs etc. is required.
+ * @ingroup crypto
*/
GNUNET_CRYPTO_QUALITY_NONCE
};
#define GNUNET_CRYPTO_HASH_LENGTH (512/8)
/**
- * @brief 0-terminated ASCII encoding of a struct GNUNET_HashCode.
+ * How many characters (without 0-terminator) are our ASCII-encoded
+ * public keys (ECDSA/EDDSA/ECDHE).
*/
-struct GNUNET_CRYPTO_HashAsciiEncoded
-{
- unsigned char encoding[104];
-};
-
+#define GNUNET_CRYPTO_PKEY_ASCII_LENGTH 52
/**
- * @brief 0-terminated ASCII encoding of a struct GNUNET_CRYPTO_ShortHashCode.
+ * @brief 0-terminated ASCII encoding of a struct GNUNET_HashCode.
*/
-struct GNUNET_CRYPTO_ShortHashAsciiEncoded
+struct GNUNET_CRYPTO_HashAsciiEncoded
{
- unsigned char short_encoding[53];
+ unsigned char encoding[104];
};
/**
- * @brief an ECC signature
+ * @brief an ECC signature using EdDSA.
+ * See https://gnunet.org/ed25519
*/
-struct GNUNET_CRYPTO_EccSignature
+struct GNUNET_CRYPTO_EddsaSignature
{
/**
};
+
/**
- * Public ECC key (always for NIST P-521) encoded in a format suitable
- * for network transmission.
+ * @brief an ECC signature using ECDSA
*/
-struct GNUNET_CRYPTO_EccPublicKey
+struct GNUNET_CRYPTO_EcdsaSignature
{
+
+ /**
+ * R value.
+ */
+ unsigned char r[256 / 8];
+
/**
- * Q consists of an x- and a y-value, each mod p (256 bits),
- * given here in affine coordinates.
+ * S value.
*/
- unsigned char q_x[256 / 8];
+ unsigned char s[256 / 8];
+};
+
+
+/**
+ * Public ECC key (always for Curve25519) encoded in a format suitable
+ * for network transmission and EdDSA signatures.
+ */
+struct GNUNET_CRYPTO_EddsaPublicKey
+{
/**
- * Q consists of an x- and a y-value, each mod p (256 bits),
- * given here in affine coordinates.
+ * Q consists of an x- and a y-value, each mod p (256 bits), given
+ * here in affine coordinates and Ed25519 standard compact format.
*/
unsigned char q_y[256 / 8];
/**
- * Private ECC key encoded for transmission.
+ * Public ECC key (always for Curve25519) encoded in a format suitable
+ * for network transmission and ECDSA signatures.
+ */
+struct GNUNET_CRYPTO_EcdsaPublicKey
+{
+ /**
+ * Q consists of an x- and a y-value, each mod p (256 bits), given
+ * here in affine coordinates and Ed25519 standard compact format.
+ */
+ unsigned char q_y[256 / 8];
+
+};
+
+
+/**
+ * The identity of the host (wraps the signing key of the peer).
+ */
+struct GNUNET_PeerIdentity
+{
+ struct GNUNET_CRYPTO_EddsaPublicKey public_key;
+};
+
+
+/**
+ * Public ECC key (always for Curve25519) encoded in a format suitable
+ * for network transmission and encryption (ECDH),
+ * See http://cr.yp.to/ecdh.html
+ */
+struct GNUNET_CRYPTO_EcdhePublicKey
+{
+ /**
+ * Q consists of an x- and a y-value, each mod p (256 bits), given
+ * here in affine coordinates and Ed25519 standard compact format.
+ */
+ unsigned char q_y[256 / 8];
+};
+
+
+/**
+ * Private ECC key encoded for transmission. To be used only for ECDH
+ * key exchange (ECDHE to be precise).
+ */
+struct GNUNET_CRYPTO_EcdhePrivateKey
+{
+ /**
+ * d is a value mod n, where n has at most 256 bits.
+ */
+ unsigned char d[256 / 8];
+
+};
+
+/**
+ * Private ECC key encoded for transmission. To be used only for ECDSA
+ * signatures.
+ */
+struct GNUNET_CRYPTO_EcdsaPrivateKey
+{
+ /**
+ * d is a value mod n, where n has at most 256 bits.
+ */
+ unsigned char d[256 / 8];
+
+};
+
+/**
+ * Private ECC key encoded for transmission. To be used only for EdDSA
+ * signatures.
*/
-struct GNUNET_CRYPTO_EccPrivateKey
+struct GNUNET_CRYPTO_EddsaPrivateKey
{
/**
* d is a value mod n, where n has at most 256 bits.
/**
* @brief type for session keys
*/
-struct GNUNET_CRYPTO_AesSessionKey
+struct GNUNET_CRYPTO_SymmetricSessionKey
{
/**
- * Actual key.
+ * Actual key for AES.
+ */
+ unsigned char aes_key[GNUNET_CRYPTO_AES_KEY_LENGTH];
+
+ /**
+ * Actual key for TwoFish.
*/
- unsigned char key[GNUNET_CRYPTO_AES_KEY_LENGTH];
+ unsigned char twofish_key[GNUNET_CRYPTO_AES_KEY_LENGTH];
};
+
GNUNET_NETWORK_STRUCT_END
/**
* @brief IV for sym cipher
*
* NOTE: must be smaller (!) in size than the
- * struct GNUNET_HashCode.
+ * `struct GNUNET_HashCode`.
*/
-struct GNUNET_CRYPTO_AesInitializationVector
+struct GNUNET_CRYPTO_SymmetricInitializationVector
{
- unsigned char iv[GNUNET_CRYPTO_AES_KEY_LENGTH / 2];
+ unsigned char aes_iv[GNUNET_CRYPTO_AES_KEY_LENGTH / 2];
+
+ unsigned char twofish_iv[GNUNET_CRYPTO_AES_KEY_LENGTH / 2];
};
};
+/**
+ * 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 ************* */
/**
- * Seed a weak random generator. Only GNUNET_CRYPTO_QUALITY_WEAK-mode generator
+ * @ingroup crypto
+ * Seed a weak random generator. Only #GNUNET_CRYPTO_QUALITY_WEAK-mode generator
* can be seeded.
*
* @param seed the seed to use
*
* @param sum current sum, initially 0
* @param buf buffer to calculate CRC over (must be 16-bit aligned)
- * @param len number of bytes in hdr, must be multiple of 2
- * @return updated crc sum (must be subjected to GNUNET_CRYPTO_crc16_finish to get actual crc16)
+ * @param len number of bytes in @a buf, must be multiple of 2
+ * @return updated crc sum (must be subjected to #GNUNET_CRYPTO_crc16_finish to get actual crc16)
*/
uint32_t
GNUNET_CRYPTO_crc16_step (uint32_t sum, const void *buf, size_t len);
/**
+ * @ingroup hash
* Calculate the checksum of a buffer in one step.
*
- * @param buf buffer to calculate CRC over (must be 16-bit aligned)
- * @param len number of bytes in hdr, must be multiple of 2
+ * @param buf buffer to calculate CRC over (must be 16-bit aligned)
+ * @param len number of bytes in @a buf, must be multiple of 2
* @return crc16 value
*/
uint16_t
/**
+ * @ingroup hash
* Compute the CRC32 checksum for the first len
* bytes of the buffer.
*
* @param buf the data over which we're taking the CRC
- * @param len the length of the buffer in bytes
+ * @param len the length of the buffer @a buf in bytes
* @return the resulting CRC32 checksum
*/
int32_t
/**
+ * @ingroup crypto
+ * Fill block with a random values.
+ *
+ * @param mode desired quality of the random number
+ * @param buffer the buffer to fill
+ * @param length buffer length
+ */
+void
+GNUNET_CRYPTO_random_block (enum GNUNET_CRYPTO_Quality mode, void *buffer, size_t length);
+
+/**
+ * @ingroup crypto
* Produce a random value.
*
* @param mode desired quality of the random number
* @param i the upper limit (exclusive) for the random number
- * @return a random value in the interval [0,i) (exclusive).
+ * @return a random value in the interval [0,@a i) (exclusive).
*/
uint32_t
GNUNET_CRYPTO_random_u32 (enum GNUNET_CRYPTO_Quality mode, uint32_t i);
/**
+ * @ingroup crypto
* Random on unsigned 64-bit values.
*
* @param mode desired quality of the random number
- * @param max value returned will be in range [0,max) (exclusive)
+ * @param max value returned will be in range [0,@a max) (exclusive)
* @return random 64-bit number
*/
uint64_t
/**
+ * @ingroup crypto
* Get an array with a random permutation of the
* numbers 0...n-1.
- * @param mode GNUNET_CRYPTO_QUALITY_STRONG if the strong (but expensive) PRNG should be used, GNUNET_CRYPTO_QUALITY_WEAK otherwise
+ * @param mode #GNUNET_CRYPTO_QUALITY_STRONG if the strong (but expensive) PRNG should be used,
+ * #GNUNET_CRYPTO_QUALITY_WEAK or #GNUNET_CRYPTO_QUALITY_NONCE otherwise
* @param n the size of the array
* @return the permutation array (allocated from heap)
*/
/**
- * Create a new Session key.
+ * @ingroup crypto
+ * Create a new random session key.
*
* @param key key to initialize
*/
void
-GNUNET_CRYPTO_aes_create_session_key (struct GNUNET_CRYPTO_AesSessionKey *key);
+GNUNET_CRYPTO_symmetric_create_session_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key);
/**
- * Encrypt a block with the public key of another
- * host that uses the same cyper.
+ * @ingroup crypto
+ * Encrypt a block using a symmetric sessionkey.
*
* @param block the block to encrypt
- * @param len the size of the block
+ * @param size the size of the @a block
* @param sessionkey the key used to encrypt
* @param iv the initialization vector to use, use INITVALUE
* for streams.
* @return the size of the encrypted block, -1 for errors
*/
ssize_t
-GNUNET_CRYPTO_aes_encrypt (const void *block, size_t len,
- const struct GNUNET_CRYPTO_AesSessionKey *sessionkey,
- const struct GNUNET_CRYPTO_AesInitializationVector
- *iv, void *result);
+GNUNET_CRYPTO_symmetric_encrypt (const void *block, size_t size,
+ const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
+ const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
+ void *result);
/**
- * Decrypt a given block with the sessionkey.
+ * @ingroup crypto
+ * Decrypt a given block using a symmetric sessionkey.
*
* @param block the data to decrypt, encoded as returned by encrypt
* @param size how big is the block?
* @return -1 on failure, size of decrypted block on success
*/
ssize_t
-GNUNET_CRYPTO_aes_decrypt (const void *block, size_t size,
- const struct GNUNET_CRYPTO_AesSessionKey *sessionkey,
- const struct GNUNET_CRYPTO_AesInitializationVector
- *iv, void *result);
+GNUNET_CRYPTO_symmetric_decrypt (const void *block, size_t size,
+ const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
+ const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
+ void *result);
/**
+ * @ingroup crypto
* @brief Derive an IV
* @param iv initialization vector
* @param skey session key
* @param salt salt for the derivation
- * @param salt_len size of the salt
+ * @param salt_len size of the @a salt
* @param ... pairs of void * & size_t for context chunks, terminated by NULL
*/
void
-GNUNET_CRYPTO_aes_derive_iv (struct GNUNET_CRYPTO_AesInitializationVector *iv,
- const struct GNUNET_CRYPTO_AesSessionKey *skey,
- const void *salt, size_t salt_len, ...);
+GNUNET_CRYPTO_symmetric_derive_iv (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
+ const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
+ const void *salt,
+ size_t salt_len, ...);
/**
* @param iv initialization vector
* @param skey session key
* @param salt salt for the derivation
- * @param salt_len size of the salt
+ * @param salt_len size of the @a salt
* @param argp pairs of void * & size_t for context chunks, terminated by NULL
*/
void
-GNUNET_CRYPTO_aes_derive_iv_v (struct GNUNET_CRYPTO_AesInitializationVector *iv,
- const struct GNUNET_CRYPTO_AesSessionKey *skey,
- const void *salt, size_t salt_len, va_list argp);
+GNUNET_CRYPTO_symmetric_derive_iv_v (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
+ const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
+ const void *salt,
+ size_t salt_len,
+ va_list argp);
/**
+ * @ingroup hash
* Convert hash to ASCII encoding.
* @param block the hash code
* @param result where to store the encoding (struct GNUNET_CRYPTO_HashAsciiEncoded can be
/**
- * Convert short hash to ASCII encoding.
- *
- * @param block the hash code
- * @param result where to store the encoding (struct GNUNET_CRYPTO_ShortHashAsciiEncoded can be
- * safely cast to char*, a '\\0' termination is set).
- */
-void
-GNUNET_CRYPTO_short_hash_to_enc (const struct GNUNET_CRYPTO_ShortHashCode * block,
- struct GNUNET_CRYPTO_ShortHashAsciiEncoded *result);
-
-
-/**
+ * @ingroup hash
* Convert ASCII encoding back to a 'struct GNUNET_HashCode'
*
* @param enc the encoding
- * @param enclen number of characters in 'enc' (without 0-terminator, which can be missing)
- * @param result where to store the GNUNET_CRYPTO_hash code
- * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
+ * @param enclen number of characters in @a enc (without 0-terminator, which can be missing)
+ * @param result where to store the hash code
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if result has the wrong encoding
*/
int
GNUNET_CRYPTO_hash_from_string2 (const char *enc, size_t enclen,
- struct GNUNET_HashCode * result);
-
-
-/**
- * Convert ASCII encoding back to a 'struct GNUNET_CRYPTO_ShortHash'
- *
- * @param enc the encoding
- * @param enclen number of characters in 'enc' (without 0-terminator, which can be missing)
- * @param result where to store the GNUNET_CRYPTO_hash code
- * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
- */
-int
-GNUNET_CRYPTO_short_hash_from_string2 (const char *enc, size_t enclen,
- struct GNUNET_CRYPTO_ShortHashCode * result);
+ struct GNUNET_HashCode *result);
/**
- * Convert ASCII encoding back to struct GNUNET_HashCode
+ * @ingroup hash
+ * Convert ASCII encoding back to `struct GNUNET_HashCode`
*
* @param enc the encoding
* @param result where to store the hash code
- * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if result has the wrong encoding
*/
#define GNUNET_CRYPTO_hash_from_string(enc, result) \
GNUNET_CRYPTO_hash_from_string2 (enc, strlen(enc), result)
/**
- * Convert ASCII encoding back to a 'struct GNUNET_CRYPTO_ShortHash'
- *
- * @param enc the encoding
- * @param result where to store the GNUNET_CRYPTO_ShortHash
- * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
- */
-#define GNUNET_CRYPTO_short_hash_from_string(enc, result) \
- GNUNET_CRYPTO_short_hash_from_string2 (enc, strlen(enc), result)
-
-
-/**
- * Compare function for ShortHashCodes, producing a total ordering
- * of all hashcodes.
+ * @ingroup hash
*
- * @param h1 some hash code
- * @param h2 some hash code
- * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2.
- */
-int
-GNUNET_CRYPTO_short_hash_cmp (const struct GNUNET_CRYPTO_ShortHashCode * h1,
- const struct GNUNET_CRYPTO_ShortHashCode * h2);
-
-/**
- * Compute the distance between 2 hashcodes.
- * The computation must be fast, not involve
- * a.a or a.e (they're used elsewhere), and
- * be somewhat consistent. And of course, the
- * result should be a positive number.
+ * Compute the distance between 2 hashcodes. The
+ * computation must be fast, not involve @a a[0] or @a a[4] (they're used
+ * elsewhere), and be somewhat consistent. And of course, the result
+ * should be a positive number.
*
* @param a some hash code
* @param b some hash code
* @return number between 0 and UINT32_MAX
*/
uint32_t
-GNUNET_CRYPTO_hash_distance_u32 (const struct GNUNET_HashCode * a,
- const struct GNUNET_HashCode * b);
+GNUNET_CRYPTO_hash_distance_u32 (const struct GNUNET_HashCode *a,
+ const struct GNUNET_HashCode *b);
/**
+ * @ingroup hash
* Compute hash of a given block.
*
* @param block the data to hash
- * @param size size of the block
+ * @param size size of the @a block
* @param ret pointer to where to write the hashcode
*/
void
/**
- * Compute short (256-bit) hash of a given block.
- *
- * @param block the data to hash
- * @param size size of the block
- * @param ret pointer to where to write the hashcode
- */
-void
-GNUNET_CRYPTO_short_hash (const void *block, size_t size,
- struct GNUNET_CRYPTO_ShortHashCode * ret);
-
-
-/**
- * Double short (256-bit) hash to create a long hash.
- *
- * @param sh short hash to double
- * @param dh where to store the (doubled) long hash (not really a hash)
- */
-void
-GNUNET_CRYPTO_short_hash_double (const struct GNUNET_CRYPTO_ShortHashCode *sh,
- struct GNUNET_HashCode *dh);
-
-
-/**
- * Truncate doubled short hash back to a short hash.
- *
- * @param dh doubled short hash to reduce again
- * @param sh where to store the short hash
- * @return GNUNET_OK on success, GNUNET_SYSERR if this was not a
- * doubled short hash
- */
-int
-GNUNET_CRYPTO_short_hash_from_truncation (const struct GNUNET_HashCode *dh,
- struct GNUNET_CRYPTO_ShortHashCode *sh);
-
-
-/**
+ * @ingroup hash
* Calculate HMAC of a message (RFC 2104)
*
* @param key secret key
* @param plaintext input plaintext
- * @param plaintext_len length of plaintext
+ * @param plaintext_len length of @a plaintext
* @param hmac where to store the hmac
*/
void
* @param res resulting hash, NULL on error
*/
typedef void (*GNUNET_CRYPTO_HashCompletedCallback) (void *cls,
- const struct GNUNET_HashCode *
- res);
+ const struct GNUNET_HashCode *res);
/**
*/
struct GNUNET_CRYPTO_FileHashContext;
+
/**
+ * @ingroup hash
* Compute the hash of an entire file.
*
* @param priority scheduling priority to use
* @param filename name of file to hash
* @param blocksize number of bytes to process in one task
* @param callback function to call upon completion
- * @param callback_cls closure for callback
+ * @param callback_cls closure for @a callback
* @return NULL on (immediate) errror
*/
struct GNUNET_CRYPTO_FileHashContext *
/**
+ * @ingroup hash
* Create a random hash code.
*
* @param mode desired quality level
*/
void
GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode,
- struct GNUNET_HashCode * result);
+ struct GNUNET_HashCode *result);
/**
- * compute result(delta) = b - a
+ * @ingroup hash
+ * compute @a result = @a b - @a a
*
* @param a some hash code
* @param b some hash code
- * @param result set to b - a
+ * @param result set to @a b - @a a
*/
void
-GNUNET_CRYPTO_hash_difference (const struct GNUNET_HashCode * a,
- const struct GNUNET_HashCode * b,
- struct GNUNET_HashCode * result);
+GNUNET_CRYPTO_hash_difference (const struct GNUNET_HashCode *a,
+ const struct GNUNET_HashCode *b,
+ struct GNUNET_HashCode *result);
/**
- * compute result(b) = a + delta
+ * @ingroup hash
+ * compute @a result = @a a + @a delta
*
* @param a some hash code
* @param delta some hash code
- * @param result set to a + delta
+ * @param result set to @a a + @a delta
*/
void
-GNUNET_CRYPTO_hash_sum (const struct GNUNET_HashCode * a,
- const struct GNUNET_HashCode * delta,
- struct GNUNET_HashCode * result);
+GNUNET_CRYPTO_hash_sum (const struct GNUNET_HashCode *a,
+ const struct GNUNET_HashCode *delta,
+ struct GNUNET_HashCode *result);
/**
+ * @ingroup hash
* compute result = a ^ b
*
* @param a some hash code
* @param b some hash code
- * @param result set to a ^ b
+ * @param result set to @a a ^ @a b
*/
void
GNUNET_CRYPTO_hash_xor (const struct GNUNET_HashCode * a, const struct GNUNET_HashCode * b,
/**
+ * @ingroup hash
* Convert a hashcode into a key.
*
* @param hc hash code that serves to generate the key
*/
void
GNUNET_CRYPTO_hash_to_aes_key (const struct GNUNET_HashCode * hc,
- struct GNUNET_CRYPTO_AesSessionKey *skey,
- struct GNUNET_CRYPTO_AesInitializationVector
- *iv);
+ struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
+ struct GNUNET_CRYPTO_SymmetricInitializationVector *iv);
/**
+ * @ingroup hash
* Obtain a bit from a hashcode.
*
- * @param code the GNUNET_CRYPTO_hash to index bit-wise
+ * @param code the `struct GNUNET_HashCode` to index bit-wise
* @param bit index into the hashcode, [0...159]
* @return Bit \a bit from hashcode \a code, -1 for invalid index
*/
int
-GNUNET_CRYPTO_hash_get_bit (const struct GNUNET_HashCode * code, unsigned int bit);
+GNUNET_CRYPTO_hash_get_bit (const struct GNUNET_HashCode *code,
+ unsigned int bit);
+
/**
+ * @ingroup hash
* Determine how many low order bits match in two
- * struct GNUNET_HashCodes. i.e. - 010011 and 011111 share
+ * `struct GNUNET_HashCodes`. i.e. - 010011 and 011111 share
* the first two lowest order bits, and therefore the
* return value is two (NOT XOR distance, nor how many
* bits match absolutely!).
*
* @param first the first hashcode
* @param second the hashcode to compare first to
- *
* @return the number of bits that match
*/
unsigned int
-GNUNET_CRYPTO_hash_matching_bits (const struct GNUNET_HashCode * first,
- const struct GNUNET_HashCode * second);
+GNUNET_CRYPTO_hash_matching_bits (const struct GNUNET_HashCode *first,
+ const struct GNUNET_HashCode *second);
/**
+ * @ingroup hash
* Compare function for HashCodes, producing a total ordering
* of all hashcodes.
*
* @param h1 some hash code
* @param h2 some hash code
- * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2.
+ * @return 1 if @a h1 > @a h2, -1 if @a h1 < @a h2 and 0 if @a h1 == @a h2.
*/
int
-GNUNET_CRYPTO_hash_cmp (const struct GNUNET_HashCode * h1, const struct GNUNET_HashCode * h2);
+GNUNET_CRYPTO_hash_cmp (const struct GNUNET_HashCode *h1,
+ const struct GNUNET_HashCode *h2);
/**
+ * @ingroup hash
* Find out which of the two GNUNET_CRYPTO_hash codes is closer to target
* in the XOR metric (Kademlia).
*
* @param h1 some hash code
* @param h2 some hash code
* @param target some hash code
- * @return -1 if h1 is closer, 1 if h2 is closer and 0 if h1==h2.
+ * @return -1 if @a h1 is closer, 1 if @a h2 is closer and 0 if @a h1== @a h2.
*/
int
-GNUNET_CRYPTO_hash_xorcmp (const struct GNUNET_HashCode * h1,
- const struct GNUNET_HashCode * h2,
- const struct GNUNET_HashCode * target);
+GNUNET_CRYPTO_hash_xorcmp (const struct GNUNET_HashCode *h1,
+ const struct GNUNET_HashCode *h2,
+ const struct GNUNET_HashCode *target);
/**
+ * @ingroup hash
* @brief Derive an authentication key
* @param key authentication key
* @param rkey root key
*/
void
GNUNET_CRYPTO_hmac_derive_key_v (struct GNUNET_CRYPTO_AuthKey *key,
- const struct GNUNET_CRYPTO_AesSessionKey *rkey,
+ const struct GNUNET_CRYPTO_SymmetricSessionKey *rkey,
const void *salt, size_t salt_len,
va_list argp);
/**
+ * @ingroup hash
* @brief Derive an authentication key
* @param key authentication key
* @param rkey root key
*/
void
GNUNET_CRYPTO_hmac_derive_key (struct GNUNET_CRYPTO_AuthKey *key,
- const struct GNUNET_CRYPTO_AesSessionKey *rkey,
+ const struct GNUNET_CRYPTO_SymmetricSessionKey *rkey,
const void *salt, size_t salt_len, ...);
+
/**
+ * @ingroup hash
* @brief Derive key
* @param result buffer for the derived key, allocated by caller
* @param out_len desired length of the derived key
* @param xtr_algo hash algorithm for the extraction phase, GCRY_MD_...
* @param prf_algo hash algorithm for the expansion phase, GCRY_MD_...
* @param xts salt
- * @param xts_len length of xts
+ * @param xts_len length of @a xts
* @param skm source key material
- * @param skm_len length of skm
+ * @param skm_len length of @a skm
* @param ... pair of void * & size_t for context chunks, terminated by NULL
- * @return GNUNET_YES on success
+ * @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_hkdf (void *result, size_t out_len, int xtr_algo, int prf_algo,
/**
+ * @ingroup hash
* @brief Derive key
* @param result buffer for the derived key, allocated by caller
* @param out_len desired length of the derived key
* @param xtr_algo hash algorithm for the extraction phase, GCRY_MD_...
* @param prf_algo hash algorithm for the expansion phase, GCRY_MD_...
* @param xts salt
- * @param xts_len length of xts
+ * @param xts_len length of @a xts
* @param skm source key material
- * @param skm_len length of skm
+ * @param skm_len length of @a skm
* @param argp va_list of void * & size_t pairs for context chunks
- * @return GNUNET_YES on success
+ * @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_hkdf_v (void *result, size_t out_len, int xtr_algo, int prf_algo,
* @param result buffer for the derived key, allocated by caller
* @param out_len desired length of the derived key
* @param xts salt
- * @param xts_len length of xts
+ * @param xts_len length of @a xts
* @param skm source key material
- * @param skm_len length of skm
+ * @param skm_len length of @a skm
* @param argp va_list of void * & size_t pairs for context chunks
- * @return GNUNET_YES on success
+ * @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_kdf_v (void *result, size_t out_len, const void *xts,
/**
+ * @ingroup hash
* @brief Derive key
* @param result buffer for the derived key, allocated by caller
* @param out_len desired length of the derived key
* @param xts salt
- * @param xts_len length of xts
+ * @param xts_len length of @a xts
* @param skm source key material
- * @param skm_len length of skm
+ * @param skm_len length of @a skm
* @param ... void * & size_t pairs for context chunks
- * @return GNUNET_YES on success
+ * @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_kdf (void *result, size_t out_len, const void *xts,
/**
- * Function called upon completion of 'GNUNET_CRYPTO_ecc_key_create_async'.
+ * @ingroup crypto
+ * Extract the public key for the given private key.
*
- * @param cls closure
- * @param pk NULL on error, otherwise the private key (which must be free'd by the callee)
- * @param emsg NULL on success, otherwise an error message
+ * @param priv the private key
+ * @param pub where to write the public key
*/
-typedef void (*GNUNET_CRYPTO_EccKeyCallback)(void *cls,
- struct GNUNET_CRYPTO_EccPrivateKey *pk,
- const char *emsg);
-
+void
+GNUNET_CRYPTO_ecdsa_key_get_public (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv,
+ struct GNUNET_CRYPTO_EcdsaPublicKey *pub);
/**
- * Free memory occupied by ECC key
+ * @ingroup crypto
+ * Extract the public key for the given private key.
*
- * @param priv pointer to the memory to free
+ * @param priv the private key
+ * @param pub where to write the public key
*/
void
-GNUNET_CRYPTO_ecc_key_free (struct GNUNET_CRYPTO_EccPrivateKey *priv);
+GNUNET_CRYPTO_eddsa_key_get_public (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv,
+ struct GNUNET_CRYPTO_EddsaPublicKey *pub);
/**
+ * @ingroup crypto
* Extract the public key for the given private key.
*
* @param priv the private key
* @param pub where to write the public key
*/
void
-GNUNET_CRYPTO_ecc_key_get_public (const struct GNUNET_CRYPTO_EccPrivateKey *priv,
- struct GNUNET_CRYPTO_EccPublicKey *pub);
+GNUNET_CRYPTO_ecdhe_key_get_public (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv,
+ struct GNUNET_CRYPTO_EcdhePublicKey *pub);
+
+
+/**
+ * Convert a public key to a string.
+ *
+ * @param pub key to convert
+ * @return string representing @a pub
+ */
+char *
+GNUNET_CRYPTO_ecdsa_public_key_to_string (const struct GNUNET_CRYPTO_EcdsaPublicKey *pub);
/**
* Convert a public key to a string.
*
* @param pub key to convert
- * @return string representing 'pub'
+ * @return string representing @a pub
*/
char *
-GNUNET_CRYPTO_ecc_public_key_to_string (const struct GNUNET_CRYPTO_EccPublicKey *pub);
+GNUNET_CRYPTO_eddsa_public_key_to_string (const struct GNUNET_CRYPTO_EddsaPublicKey *pub);
/**
* Convert a string representing a public key to a public key.
*
* @param enc encoded public key
- * @param enclen number of bytes in enc (without 0-terminator)
+ * @param enclen number of bytes in @a enc (without 0-terminator)
* @param pub where to store the public key
- * @return GNUNET_OK on success
+ * @return #GNUNET_OK on success
*/
int
-GNUNET_CRYPTO_ecc_public_key_from_string (const char *enc,
- size_t enclen,
- struct GNUNET_CRYPTO_EccPublicKey *pub);
+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.
+ *
+ * @param enc encoded public key
+ * @param enclen number of bytes in @a enc (without 0-terminator)
+ * @param pub where to store the public key
+ * @return #GNUNET_OK on success
+ */
+int
+GNUNET_CRYPTO_eddsa_public_key_from_string (const char *enc,
+ size_t enclen,
+ struct GNUNET_CRYPTO_EddsaPublicKey *pub);
+
+
+/**
+ * @ingroup crypto
+ * Create a new private key by reading it from a file. If the
+ * files does not exist, create a new key and write it to the
+ * file. Caller must free return value. Note that this function
+ * can not guarantee that another process might not be trying
+ * the same operation on the same file at the same time.
+ * If the contents of the file
+ * are invalid the old file is deleted and a fresh key is
+ * created.
+ *
+ * @param filename name of file to use to store the key
+ * @return new private key, NULL on error (for example,
+ * permission denied); free using #GNUNET_free
+ */
+struct GNUNET_CRYPTO_EcdsaPrivateKey *
+GNUNET_CRYPTO_ecdsa_key_create_from_file (const char *filename);
+
+
+/**
+ * @ingroup crypto
* Create a new private key by reading it from a file. If the
* files does not exist, create a new key and write it to the
* file. Caller must free return value. Note that this function
*
* @param filename name of file to use to store the key
* @return new private key, NULL on error (for example,
- * permission denied)
+ * permission denied); free using #GNUNET_free
*/
-struct GNUNET_CRYPTO_EccPrivateKey *
-GNUNET_CRYPTO_ecc_key_create_from_file (const char *filename);
+struct GNUNET_CRYPTO_EddsaPrivateKey *
+GNUNET_CRYPTO_eddsa_key_create_from_file (const char *filename);
+
+struct GNUNET_CONFIGURATION_Handle;
/**
+ * @ingroup crypto
* Create a new private key by reading our peer's key from
* the file specified in the configuration.
*
+ * @param cfg the configuration to use
* @return new private key, NULL on error (for example,
- * permission denied)
+ * permission denied); free using #GNUNET_free
+ */
+struct GNUNET_CRYPTO_EddsaPrivateKey *
+GNUNET_CRYPTO_eddsa_key_create_from_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg);
+
+
+/**
+ * @ingroup crypto
+ * Create a new private key. Caller must free return value.
+ *
+ * @return fresh private key; free using #GNUNET_free
+ */
+struct GNUNET_CRYPTO_EcdsaPrivateKey *
+GNUNET_CRYPTO_ecdsa_key_create (void);
+
+
+/**
+ * @ingroup crypto
+ * Create a new private key. Caller must free return value.
+ *
+ * @return fresh private key; free using #GNUNET_free
+ */
+struct GNUNET_CRYPTO_EddsaPrivateKey *
+GNUNET_CRYPTO_eddsa_key_create (void);
+
+
+/**
+ * @ingroup crypto
+ * Create a new private key. Caller must free return value.
+ *
+ * @return fresh private key; free using #GNUNET_free
*/
-struct GNUNET_CRYPTO_EccPrivateKey *
-GNUNET_CRYPTO_ecc_key_create_from_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg);
+struct GNUNET_CRYPTO_EcdhePrivateKey *
+GNUNET_CRYPTO_ecdhe_key_create (void);
/**
- * Create a new private key. Caller must free return value. Blocking version
- * (blocks to gather entropy).
+ * @ingroup crypto
+ * Clear memory that was used to store a private key.
*
- * @return fresh private key
+ * @param pk location of the key
*/
-struct GNUNET_CRYPTO_EccPrivateKey *
-GNUNET_CRYPTO_ecc_key_create (void);
+void
+GNUNET_CRYPTO_eddsa_key_clear (struct GNUNET_CRYPTO_EddsaPrivateKey *pk);
/**
+ * @ingroup crypto
+ * Clear memory that was used to store a private key.
+ *
+ * @param pk location of the key
+ */
+void
+GNUNET_CRYPTO_ecdsa_key_clear (struct GNUNET_CRYPTO_EcdsaPrivateKey *pk);
+
+/**
+ * @ingroup crypto
+ * Clear memory that was used to store a private key.
+ *
+ * @param pk location of the key
+ */
+void
+GNUNET_CRYPTO_ecdhe_key_clear (struct GNUNET_CRYPTO_EcdhePrivateKey *pk);
+
+
+/**
+ * @ingroup crypto
+ * Get the shared private key we use for anonymous users.
+ *
+ * @return "anonymous" private key; do not free
+ */
+const struct GNUNET_CRYPTO_EcdsaPrivateKey *
+GNUNET_CRYPTO_ecdsa_key_get_anonymous (void);
+
+
+/**
+ * @ingroup crypto
* Setup a hostkey file for a peer given the name of the
* configuration file (!). This function is used so that
* at a later point code can be certain that reading a
* hostkey is fast (for example in time-dependent testcases).
- *
+*
* @param cfg_name name of the configuration file to use
*/
void
-GNUNET_CRYPTO_ecc_setup_hostkey (const char *cfg_name);
+GNUNET_CRYPTO_eddsa_setup_hostkey (const char *cfg_name);
/**
+ * @ingroup crypto
* Retrieve the identity of the host's peer.
*
* @param cfg configuration to use
* @param dst pointer to where to write the peer identity
- * @return GNUNET_OK on success, GNUNET_SYSERR if the identity
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if the identity
* could not be retrieved
*/
int
-GNUNET_CRYPTO_get_host_identity (const struct GNUNET_CONFIGURATION_Handle *cfg,
+GNUNET_CRYPTO_get_peer_identity (const struct GNUNET_CONFIGURATION_Handle *cfg,
struct GNUNET_PeerIdentity *dst);
+/**
+ * Compare two Peer Identities.
+ *
+ * @param first first peer identity
+ * @param second second peer identity
+ * @return bigger than 0 if first > second,
+ * 0 if they are the same
+ * smaller than 0 if second > first
+ */
+int
+GNUNET_CRYPTO_cmp_peer_identity (const struct GNUNET_PeerIdentity *first,
+ const struct GNUNET_PeerIdentity *second);
+
/**
+ * @ingroup crypto
* Derive key material from a public and a private ECC key.
*
- * @param key private key to use for the ECDH (x)
- * @param pub public key to use for the ECDY (yG)
+ * @param priv private key to use for the ECDH (x)
+ * @param pub public key to use for the ECDH (yG)
* @param key_material where to write the key material (xyG)
- * @return GNUNET_SYSERR on error, GNUNET_OK on success
+ * @return #GNUNET_SYSERR on error, #GNUNET_OK on success
*/
int
-GNUNET_CRYPTO_ecc_ecdh (const struct GNUNET_CRYPTO_EccPrivateKey *key,
- const struct GNUNET_CRYPTO_EccPublicKey *pub,
+GNUNET_CRYPTO_ecc_ecdh (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv,
+ const struct GNUNET_CRYPTO_EcdhePublicKey *pub,
struct GNUNET_HashCode *key_material);
/**
- * Sign a given block.
+ * @ingroup crypto
+ * EdDSA sign a given block.
+ *
+ * @param priv private key to use for the signing
+ * @param purpose what to sign (size, purpose)
+ * @param sig where to write the signature
+ * @return #GNUNET_SYSERR on error, #GNUNET_OK on success
+ */
+int
+GNUNET_CRYPTO_eddsa_sign (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv,
+ const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
+ struct GNUNET_CRYPTO_EddsaSignature *sig);
+
+
+/**
+ * @ingroup crypto
+ * ECDSA Sign a given block.
*
* @param priv private key to use for the signing
* @param purpose what to sign (size, purpose)
* @param sig where to write the signature
- * @return GNUNET_SYSERR on error, GNUNET_OK on success
+ * @return #GNUNET_SYSERR on error, #GNUNET_OK on success
+ */
+int
+GNUNET_CRYPTO_ecdsa_sign (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv,
+ const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
+ struct GNUNET_CRYPTO_EcdsaSignature *sig);
+
+/**
+ * @ingroup crypto
+ * Verify EdDSA signature.
+ *
+ * @param purpose what is the purpose that the signature should have?
+ * @param validate block to validate (size, purpose, data)
+ * @param sig signature that is being validated
+ * @param pub public key of the signer
+ * @returns #GNUNET_OK if ok, #GNUNET_SYSERR if invalid
*/
int
-GNUNET_CRYPTO_ecc_sign (const struct GNUNET_CRYPTO_EccPrivateKey *priv,
- const struct GNUNET_CRYPTO_EccSignaturePurpose *purpose,
- struct GNUNET_CRYPTO_EccSignature *sig);
+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 signature.
+ * @ingroup crypto
+ * Verify ECDSA signature.
*
* @param purpose what is the purpose that the signature should have?
* @param validate block to validate (size, purpose, data)
* @param sig signature that is being validated
* @param pub public key of the signer
- * @returns GNUNET_OK if ok, GNUNET_SYSERR if invalid
+ * @returns #GNUNET_OK if ok, #GNUNET_SYSERR if invalid
*/
int
-GNUNET_CRYPTO_ecc_verify (uint32_t purpose,
- const struct GNUNET_CRYPTO_EccSignaturePurpose
- *validate,
- const struct GNUNET_CRYPTO_EccSignature *sig,
- const struct GNUNET_CRYPTO_EccPublicKey *pub);
+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);
/**
+ * @ingroup crypto
* Derive a private key from a given private key and a label.
* Essentially calculates a private key 'h = H(l,P) * d mod n'
* where n is the size of the ECC group and P is the public
*
* @param priv original private key
* @param label label to use for key deriviation
+ * @param context additional context to use for HKDF of 'h';
+ * typically the name of the subsystem/application
* @return derived private key
*/
-struct GNUNET_CRYPTO_EccPrivateKey *
-GNUNET_CRYPTO_ecc_key_derive (const struct GNUNET_CRYPTO_EccPrivateKey *priv,
- const char *label);
+struct GNUNET_CRYPTO_EcdsaPrivateKey *
+GNUNET_CRYPTO_ecdsa_private_key_derive (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv,
+ const char *label,
+ const char *context);
/**
+ * @ingroup crypto
* Derive a public key from a given public key and a label.
* Essentially calculates a public key 'V = H(l,P) * P'.
*
* @param pub original public key
* @param label label to use for key deriviation
+ * @param context additional context to use for HKDF of 'h'.
+ * typically the name of the subsystem/application
* @param result where to write the derived public key
*/
void
-GNUNET_CRYPTO_ecc_public_key_derive (const struct GNUNET_CRYPTO_EccPublicKey *pub,
- const char *label,
- struct GNUNET_CRYPTO_EccPublicKey *result);
+GNUNET_CRYPTO_ecdsa_public_key_derive (const struct GNUNET_CRYPTO_EcdsaPublicKey *pub,
+ const char *label,
+ const char *context,
+ 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 desired_ops How many homomorphic ops the caller intends to use
+ * @param[out] ciphertext Encrytion of @a plaintext with @a public_key.
+ * @return guaranteed number of supported homomorphic operations >= 1,
+ * or desired_ops, in case that is lower,
+ * or -1 if less than one homomorphic operation is possible
+ */
+int
+GNUNET_CRYPTO_paillier_encrypt (const struct GNUNET_CRYPTO_PaillierPublicKey *public_key,
+ const gcry_mpi_t m,
+ int desired_ops,
+ 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