/*
This file is part of GNUnet.
Copyright (C) 2001-2013 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
*/
/**
* @file include/gnunet_crypto_lib.h
* @brief cryptographic primitives for GNUnet
*
* @author Christian Grothoff
* @author Krista Bennett
* @author Gerd Knorr
* @author Ioana Patrascu
* @author Tzvetan Horozov
* @author Jeffrey Burdges
*
* @defgroup crypto Crypto library: cryptographic operations
* Provides cryptographic primitives.
*
* @see [Documentation](https://gnunet.org/crypto-api)
*
* @defgroup hash Crypto library: hash operations
* Provides hashing and operations on hashes.
*
* @see [Documentation](https://gnunet.org/crypto-api)
*/
#ifndef GNUNET_CRYPTO_LIB_H
#define GNUNET_CRYPTO_LIB_H
#ifdef __cplusplus
extern "C"
{
#if 0 /* keep Emacsens' auto-indent happy */
}
#endif
#endif
/**
* @brief A 512-bit hashcode. These are the default length for GNUnet, using SHA-512.
*/
struct GNUNET_HashCode
{
uint32_t bits[512 / 8 / sizeof (uint32_t)]; /* = 16 */
};
/**
* @brief A 256-bit hashcode. Used under special conditions, like when space
* is critical and security is not impacted by it.
*/
struct GNUNET_ShortHashCode
{
uint32_t bits[256 / 8 / sizeof (uint32_t)]; /* = 8 */
};
/**
* The identity of the host (wraps the signing key of the peer).
*/
struct GNUNET_PeerIdentity;
#include "gnunet_common.h"
#include
/**
* Maximum length of an ECC signature.
* Note: round up to multiple of 8 minus 2 for alignment.
*/
#define GNUNET_CRYPTO_ECC_SIGNATURE_DATA_ENCODING_LENGTH 126
/**
* 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
};
/**
* @brief length of the sessionkey in bytes (256 BIT sessionkey)
*/
#define GNUNET_CRYPTO_AES_KEY_LENGTH (256/8)
/**
* Length of a hash value
*/
#define GNUNET_CRYPTO_HASH_LENGTH (512/8)
/**
* How many characters (without 0-terminator) are our ASCII-encoded
* public keys (ECDSA/EDDSA/ECDHE).
*/
#define GNUNET_CRYPTO_PKEY_ASCII_LENGTH 52
/**
* @brief 0-terminated ASCII encoding of a struct GNUNET_HashCode.
*/
struct GNUNET_CRYPTO_HashAsciiEncoded
{
unsigned char encoding[104];
};
GNUNET_NETWORK_STRUCT_BEGIN
/**
* @brief header of what an ECC signature signs
* this must be followed by "size - 8" bytes of
* the actual signed data
*/
struct GNUNET_CRYPTO_EccSignaturePurpose
{
/**
* How many bytes does this signature sign?
* (including this purpose header); in network
* byte order (!).
*/
uint32_t size GNUNET_PACKED;
/**
* What does this signature vouch for? This
* must contain a GNUNET_SIGNATURE_PURPOSE_XXX
* constant (from gnunet_signatures.h). In
* network byte order!
*/
uint32_t purpose GNUNET_PACKED;
};
/**
* @brief an ECC signature using EdDSA.
* See https://gnunet.org/ed25519
*/
struct GNUNET_CRYPTO_EddsaSignature
{
/**
* R value.
*/
unsigned char r[256 / 8];
/**
* S value.
*/
unsigned char s[256 / 8];
};
/**
* @brief an ECC signature using ECDSA
*/
struct GNUNET_CRYPTO_EcdsaSignature
{
/**
* R value.
*/
unsigned char r[256 / 8];
/**
* S value.
*/
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 and Ed25519 standard compact format.
*/
unsigned char q_y[256 / 8];
};
/**
* 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_EddsaPrivateKey
{
/**
* d is a value mod n, where n has at most 256 bits.
*/
unsigned char d[256 / 8];
};
/**
* @brief type for session keys
*/
struct GNUNET_CRYPTO_SymmetricSessionKey
{
/**
* Actual key for AES.
*/
unsigned char aes_key[GNUNET_CRYPTO_AES_KEY_LENGTH];
/**
* Actual key for TwoFish.
*/
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_CRYPTO_SymmetricInitializationVector
{
unsigned char aes_iv[GNUNET_CRYPTO_AES_KEY_LENGTH / 2];
unsigned char twofish_iv[GNUNET_CRYPTO_AES_KEY_LENGTH / 2];
};
/**
* @brief type for (message) authentication keys
*/
struct GNUNET_CRYPTO_AuthKey
{
unsigned char key[GNUNET_CRYPTO_HASH_LENGTH];
};
/**
* 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 private 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,
* in network byte order (NBO).
*/
int32_t remaining_ops GNUNET_PACKED;
/**
* The bits of the ciphertext.
*/
unsigned char bits[GNUNET_CRYPTO_PAILLIER_BITS * 2 / 8];
};
/* **************** Functions and Macros ************* */
/**
* @ingroup crypto
* Seed a weak random generator. Only #GNUNET_CRYPTO_QUALITY_WEAK-mode generator
* can be seeded.
*
* @param seed the seed to use
*/
void
GNUNET_CRYPTO_seed_weak_random (int32_t seed);
/**
* @ingroup hash
* Calculate the checksum of a buffer in one step.
*
* @param buf buffer to calculate CRC over
* @param len number of bytes in @a buf
* @return crc8 value
*/
uint8_t
GNUNET_CRYPTO_crc8_n (const void *buf,
size_t len);
/**
* Perform an incremental step in a CRC16 (for TCP/IP) calculation.
*
* @param sum current sum, initially 0
* @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 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);
/**
* Convert results from GNUNET_CRYPTO_crc16_step to final crc16.
*
* @param sum cummulative sum
* @return crc16 value
*/
uint16_t
GNUNET_CRYPTO_crc16_finish (uint32_t sum);
/**
* @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 @a buf, must be multiple of 2
* @return crc16 value
*/
uint16_t
GNUNET_CRYPTO_crc16_n (const void *buf,
size_t len);
/**
* @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 @a buf in bytes
* @return the resulting CRC32 checksum
*/
int32_t
GNUNET_CRYPTO_crc32_n (const void *buf,
size_t len);
/**
* @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,@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,@a max) (exclusive)
* @return random 64-bit number
*/
uint64_t
GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode,
uint64_t max);
/**
* @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 or #GNUNET_CRYPTO_QUALITY_NONCE otherwise
* @param n the size of the array
* @return the permutation array (allocated from heap)
*/
unsigned int *
GNUNET_CRYPTO_random_permute (enum GNUNET_CRYPTO_Quality mode,
unsigned int n);
/**
* @ingroup crypto
* Create a new random session key.
*
* @param key key to initialize
*/
void
GNUNET_CRYPTO_symmetric_create_session_key (struct GNUNET_CRYPTO_SymmetricSessionKey *key);
/**
* @ingroup crypto
* Encrypt a block using a symmetric sessionkey.
*
* @param block the block to encrypt
* @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_symmetric_encrypt (const void *block,
size_t size,
const struct GNUNET_CRYPTO_SymmetricSessionKey *sessionkey,
const struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
void *result);
/**
* @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?
* @param sessionkey the key used to decrypt
* @param iv the initialization vector to use
* @param result address to store the result at
* @return -1 on failure, size of decrypted block on success
*/
ssize_t
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 @a salt
* @param ... pairs of void * & size_t for context chunks, terminated by NULL
*/
void
GNUNET_CRYPTO_symmetric_derive_iv (struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
const struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
const void *salt,
size_t salt_len, ...);
/**
* @brief Derive an IV
* @param iv initialization vector
* @param skey session key
* @param salt salt for the derivation
* @param salt_len size of the @a salt
* @param argp pairs of void * & size_t for context chunks, terminated by NULL
*/
void
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
* safely cast to char*, a '\\0' termination is set).
*/
void
GNUNET_CRYPTO_hash_to_enc (const struct GNUNET_HashCode *block,
struct GNUNET_CRYPTO_HashAsciiEncoded *result);
/**
* @ingroup hash
* Convert ASCII encoding back to a 'struct GNUNET_HashCode'
*
* @param enc the 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);
/**
* @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
*/
#define GNUNET_CRYPTO_hash_from_string(enc, result) \
GNUNET_CRYPTO_hash_from_string2 (enc, strlen(enc), result)
/**
* @ingroup hash
*
* 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);
/**
* @ingroup hash
* Compute hash of a given block.
*
* @param block the data to hash
* @param size size of the @a block
* @param ret pointer to where to write the hashcode
*/
void
GNUNET_CRYPTO_hash (const void *block,
size_t size,
struct GNUNET_HashCode *ret);
/**
* Context for cummulative hashing.
*/
struct GNUNET_HashContext;
/**
* Start incremental hashing operation.
*
* @return context for incremental hash computation
*/
struct GNUNET_HashContext *
GNUNET_CRYPTO_hash_context_start (void);
/**
* Add data to be hashed.
*
* @param hc cummulative hash context
* @param buf data to add
* @param size number of bytes in @a buf
*/
void
GNUNET_CRYPTO_hash_context_read (struct GNUNET_HashContext *hc,
const void *buf,
size_t size);
/**
* Finish the hash computation.
*
* @param hc hash context to use, is freed in the process
* @param r_hash where to write the latest / final hash code
*/
void
GNUNET_CRYPTO_hash_context_finish (struct GNUNET_HashContext *hc,
struct GNUNET_HashCode *r_hash);
/**
* Abort hashing, do not bother calculating final result.
*
* @param hc hash context to destroy
*/
void
GNUNET_CRYPTO_hash_context_abort (struct GNUNET_HashContext *hc);
/**
* @ingroup hash
* Calculate HMAC of a message (RFC 2104)
*
* @param key secret key
* @param plaintext input plaintext
* @param plaintext_len length of @a plaintext
* @param hmac where to store the hmac
*/
void
GNUNET_CRYPTO_hmac (const struct GNUNET_CRYPTO_AuthKey *key,
const void *plaintext,
size_t plaintext_len,
struct GNUNET_HashCode *hmac);
/**
* Function called once the hash computation over the
* specified file has completed.
*
* @param cls closure
* @param res resulting hash, NULL on error
*/
typedef void
(*GNUNET_CRYPTO_HashCompletedCallback) (void *cls,
const struct GNUNET_HashCode *res);
/**
* Handle to file hashing operation.
*/
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 @a callback
* @return NULL on (immediate) errror
*/
struct GNUNET_CRYPTO_FileHashContext *
GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
const char *filename,
size_t blocksize,
GNUNET_CRYPTO_HashCompletedCallback callback,
void *callback_cls);
/**
* Cancel a file hashing operation.
*
* @param fhc operation to cancel (callback must not yet have been invoked)
*/
void
GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc);
/**
* @ingroup hash
* Create a random hash code.
*
* @param mode desired quality level
* @param result hash code that is randomized
*/
void
GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode,
struct GNUNET_HashCode *result);
/**
* @ingroup hash
* compute @a result = @a b - @a a
*
* @param a some hash code
* @param b some hash code
* @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);
/**
* @ingroup hash
* compute @a result = @a a + @a delta
*
* @param a some hash code
* @param delta some hash code
* @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);
/**
* @ingroup hash
* compute result = a ^ b
*
* @param a some hash code
* @param b some hash code
* @param result set to @a a ^ @a b
*/
void
GNUNET_CRYPTO_hash_xor (const struct GNUNET_HashCode *a,
const struct GNUNET_HashCode *b,
struct GNUNET_HashCode *result);
/**
* @ingroup hash
* Convert a hashcode into a key.
*
* @param hc hash code that serves to generate the key
* @param skey set to a valid session key
* @param iv set to a valid initialization vector
*/
void
GNUNET_CRYPTO_hash_to_aes_key (const struct GNUNET_HashCode * hc,
struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
struct GNUNET_CRYPTO_SymmetricInitializationVector *iv);
/**
* @ingroup hash
* Obtain a bit from a hashcode.
*
* @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);
/**
* @ingroup hash
* Determine how many low order bits match in two
* `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);
/**
* @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 @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);
/**
* @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 @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);
/**
* @ingroup hash
* @brief Derive an authentication key
* @param key authentication key
* @param rkey root key
* @param salt salt
* @param salt_len size of the salt
* @param argp pair of void * & size_t for context chunks, terminated by NULL
*/
void
GNUNET_CRYPTO_hmac_derive_key_v (struct GNUNET_CRYPTO_AuthKey *key,
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
* @param salt salt
* @param salt_len size of the salt
* @param ... pair of void * & size_t for context chunks, terminated by NULL
*/
void
GNUNET_CRYPTO_hmac_derive_key (struct GNUNET_CRYPTO_AuthKey *key,
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 @a xts
* @param skm source key material
* @param skm_len length of @a skm
* @param ... pair of void * & size_t for context chunks, terminated by NULL
* @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_hkdf (void *result,
size_t out_len,
int xtr_algo,
int prf_algo,
const void *xts,
size_t xts_len,
const void *skm,
size_t skm_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 @a xts
* @param skm source key material
* @param skm_len length of @a skm
* @param argp va_list of void * & size_t pairs for context chunks
* @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_hkdf_v (void *result,
size_t out_len,
int xtr_algo,
int prf_algo,
const void *xts,
size_t xts_len,
const void *skm,
size_t skm_len,
va_list argp);
/**
* @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 @a xts
* @param skm source key material
* @param skm_len length of @a skm
* @param argp va_list of void * & size_t pairs for context chunks
* @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_kdf_v (void *result,
size_t out_len,
const void *xts,
size_t xts_len,
const void *skm,
size_t skm_len,
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
* @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 @a xts
* @param skm source key material
* @param skm_len length of @a skm
* @param ... void * & size_t pairs for context chunks
* @return #GNUNET_YES on success
*/
int
GNUNET_CRYPTO_kdf (void *result,
size_t out_len,
const void *xts,
size_t xts_len,
const void *skm,
size_t skm_len,
...);
/**
* @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_ecdsa_key_get_public (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv,
struct GNUNET_CRYPTO_EcdsaPublicKey *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_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_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 private key to a string.
*
* @param priv key to convert
* @return string representing @a pub
*/
char *
GNUNET_CRYPTO_eddsa_private_key_to_string (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv);
/**
* Convert a public key to a string.
*
* @param pub key to convert
* @return string representing @a pub
*/
char *
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 @a enc (without 0-terminator)
* @param pub where to store the public key
* @return #GNUNET_OK on success
*/
int
GNUNET_CRYPTO_ecdsa_public_key_from_string (const char *enc,
size_t enclen,
struct GNUNET_CRYPTO_EcdsaPublicKey *pub);
/**
* Convert a string representing a private key to a private key.
*
* @param enc encoded public key
* @param enclen number of bytes in @a enc (without 0-terminator)
* @param priv where to store the private key
* @return #GNUNET_OK on success
*/
int
GNUNET_CRYPTO_eddsa_private_key_from_string (const char *enc,
size_t enclen,
struct GNUNET_CRYPTO_EddsaPrivateKey *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
* 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_EddsaPrivateKey *
GNUNET_CRYPTO_eddsa_key_create_from_file (const char *filename);
/**
* Forward declaration to simplify #include-structure.
*/
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); 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. Clear with #GNUNET_CRYPTO_ecdhe_key_clear().
*
* @param[out] pk set to fresh private key;
* @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
*/
int
GNUNET_CRYPTO_ecdhe_key_create2 (struct GNUNET_CRYPTO_EcdhePrivateKey *pk);
/**
* @ingroup crypto
* Create a new private key. Caller must free return value.
*
* @return fresh private key; free using #GNUNET_free
*/
struct GNUNET_CRYPTO_EcdhePrivateKey *
GNUNET_CRYPTO_ecdhe_key_create (void);
/**
* @ingroup crypto
* Clear memory that was used to store a private key.
*
* @param pk location of the key
*/
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_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
* could not be retrieved
*/
int
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);
/**
* Internal structure used to cache pre-calculated values for DLOG calculation.
*/
struct GNUNET_CRYPTO_EccDlogContext;
/**
* Point on a curve (always for Curve25519) encoded in a format suitable
* for network transmission (ECDH), see http://cr.yp.to/ecdh.html.
*/
struct GNUNET_CRYPTO_EccPoint
{
/**
* 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];
};
/**
* Do pre-calculation for ECC discrete logarithm for small factors.
*
* @param max maximum value the factor can be
* @param mem memory to use (should be smaller than @a max), must not be zero.
* @return NULL on error
*/
struct GNUNET_CRYPTO_EccDlogContext *
GNUNET_CRYPTO_ecc_dlog_prepare (unsigned int max,
unsigned int mem);
/**
* Calculate ECC discrete logarithm for small factors.
* Opposite of #GNUNET_CRYPTO_ecc_dexp().
*
* @param dlc precalculated values, determine range of factors
* @param input point on the curve to factor
* @return INT_MAX if dlog failed, otherwise the factor
*/
int
GNUNET_CRYPTO_ecc_dlog (struct GNUNET_CRYPTO_EccDlogContext *edc,
gcry_mpi_point_t input);
/**
* Multiply the generator g of the elliptic curve by @a val
* to obtain the point on the curve representing @a val.
* Afterwards, point addition will correspond to integer
* addition. #GNUNET_CRYPTO_ecc_dlog() can be used to
* convert a point back to an integer (as long as the
* integer is smaller than the MAX of the @a edc context).
*
* @param edc calculation context for ECC operations
* @param val value to encode into a point
* @return representation of the value as an ECC point,
* must be freed using #GNUNET_CRYPTO_ecc_free()
*/
gcry_mpi_point_t
GNUNET_CRYPTO_ecc_dexp (struct GNUNET_CRYPTO_EccDlogContext *edc,
int val);
/**
* Multiply the generator g of the elliptic curve by @a val
* to obtain the point on the curve representing @a val.
*
* @param edc calculation context for ECC operations
* @param val (positive) value to encode into a point
* @return representation of the value as an ECC point,
* must be freed using #GNUNET_CRYPTO_ecc_free()
*/
gcry_mpi_point_t
GNUNET_CRYPTO_ecc_dexp_mpi (struct GNUNET_CRYPTO_EccDlogContext *edc,
gcry_mpi_t val);
/**
* Multiply the point @a p on the elliptic curve by @a val.
*
* @param edc calculation context for ECC operations
* @param p point to multiply
* @param val (positive) value to encode into a point
* @return representation of the value as an ECC point,
* must be freed using #GNUNET_CRYPTO_ecc_free()
*/
gcry_mpi_point_t
GNUNET_CRYPTO_ecc_pmul_mpi (struct GNUNET_CRYPTO_EccDlogContext *edc,
gcry_mpi_point_t p,
gcry_mpi_t val);
/**
* Convert point value to binary representation.
*
* @param edc calculation context for ECC operations
* @param point computational point representation
* @param[out] bin binary point representation
*/
void
GNUNET_CRYPTO_ecc_point_to_bin (struct GNUNET_CRYPTO_EccDlogContext *edc,
gcry_mpi_point_t point,
struct GNUNET_CRYPTO_EccPoint *bin);
/**
* Convert binary representation of a point to computational representation.
*
* @param edc calculation context for ECC operations
* @param bin binary point representation
* @return computational representation
*/
gcry_mpi_point_t
GNUNET_CRYPTO_ecc_bin_to_point (struct GNUNET_CRYPTO_EccDlogContext *edc,
const struct GNUNET_CRYPTO_EccPoint *bin);
/**
* Add two points on the elliptic curve.
*
* @param edc calculation context for ECC operations
* @param a some value
* @param b some value
* @return @a a + @a b, must be freed using #GNUNET_CRYPTO_ecc_free()
*/
gcry_mpi_point_t
GNUNET_CRYPTO_ecc_add (struct GNUNET_CRYPTO_EccDlogContext *edc,
gcry_mpi_point_t a,
gcry_mpi_point_t b);
/**
* Obtain a random point on the curve and its
* additive inverse. Both returned values
* must be freed using #GNUNET_CRYPTO_ecc_free().
*
* @param edc calculation context for ECC operations
* @param[out] r set to a random point on the curve
* @param[out] r_inv set to the additive inverse of @a r
*/
void
GNUNET_CRYPTO_ecc_rnd (struct GNUNET_CRYPTO_EccDlogContext *edc,
gcry_mpi_point_t *r,
gcry_mpi_point_t *r_inv);
/**
* Obtain a random scalar for point multiplication on the curve and
* its multiplicative inverse.
*
* @param edc calculation context for ECC operations
* @param[out] r set to a random scalar on the curve
* @param[out] r_inv set to the multiplicative inverse of @a r
*/
void
GNUNET_CRYPTO_ecc_rnd_mpi (struct GNUNET_CRYPTO_EccDlogContext *edc,
gcry_mpi_t *r,
gcry_mpi_t *r_inv);
/**
* Generate a random value mod n.
*
* @param edc ECC context
* @return random value mod n.
*/
gcry_mpi_t
GNUNET_CRYPTO_ecc_random_mod_n (struct GNUNET_CRYPTO_EccDlogContext *edc);
/**
* Free a point value returned by the API.
*
* @param p point to free
*/
void
GNUNET_CRYPTO_ecc_free (gcry_mpi_point_t p);
/**
* Release precalculated values.
*
* @param dlc dlog context
*/
void
GNUNET_CRYPTO_ecc_dlog_release (struct GNUNET_CRYPTO_EccDlogContext *dlc);
/**
* @ingroup crypto
* Derive key material from a public and a private ECC key.
*
* @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
*/
int
GNUNET_CRYPTO_ecc_ecdh (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv,
const struct GNUNET_CRYPTO_EcdhePublicKey *pub,
struct GNUNET_HashCode *key_material);
/**
* @ingroup crypto
* Derive key material from a ECDH public key and a private EdDSA key.
* Dual to #GNUNET_CRRYPTO_ecdh_eddsa.
*
* @param priv private key from EdDSA 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 H(h(x)yG)
* @return #GNUNET_SYSERR on error, #GNUNET_OK on success
*/
int
GNUNET_CRYPTO_eddsa_ecdh (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv,
const struct GNUNET_CRYPTO_EcdhePublicKey *pub,
struct GNUNET_HashCode *key_material);
/**
* @ingroup crypto
* Derive key material from a ECDH public key and a private ECDSA key.
* Dual to #GNUNET_CRRYPTO_ecdh_ecdsa.
*
* @param priv private key from ECDSA 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 H(h(x)yG)
* @return #GNUNET_SYSERR on error, #GNUNET_OK on success
*/
int
GNUNET_CRYPTO_ecdsa_ecdh (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv,
const struct GNUNET_CRYPTO_EcdhePublicKey *pub,
struct GNUNET_HashCode *key_material);
/**
* @ingroup crypto
* Derive key material from a EdDSA public key and a private ECDH key.
* Dual to #GNUNET_CRRYPTO_eddsa_ecdh.
*
* @param priv private key to use for the ECDH (y)
* @param pub public key from EdDSA to use for the ECDH (X=h(x)G)
* @param key_material where to write the key material H(yX)=H(h(x)yG)
* @return #GNUNET_SYSERR on error, #GNUNET_OK on success
*/
int
GNUNET_CRYPTO_ecdh_eddsa (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv,
const struct GNUNET_CRYPTO_EddsaPublicKey *pub,
struct GNUNET_HashCode *key_material);
/**
* @ingroup crypto
* Derive key material from a EcDSA public key and a private ECDH key.
* Dual to #GNUNET_CRRYPTO_ecdsa_ecdh.
*
* @param priv private key to use for the ECDH (y)
* @param pub public key from ECDSA to use for the ECDH (X=h(x)G)
* @param key_material where to write the key material H(yX)=H(h(x)yG)
* @return #GNUNET_SYSERR on error, #GNUNET_OK on success
*/
int
GNUNET_CRYPTO_ecdh_ecdsa (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv,
const struct GNUNET_CRYPTO_EcdsaPublicKey *pub,
struct GNUNET_HashCode *key_material);
/**
* @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
*/
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_eddsa_verify (uint32_t purpose,
const struct GNUNET_CRYPTO_EccSignaturePurpose *validate,
const struct GNUNET_CRYPTO_EddsaSignature *sig,
const struct GNUNET_CRYPTO_EddsaPublicKey *pub);
/**
* @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
*/
int
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
* key associated with the private key 'd'.
*
* @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_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_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);
/* ********* Chaum-style RSA-based blind signatures ******************* */
/**
* The private information of an RSA key pair.
*/
struct GNUNET_CRYPTO_RsaPrivateKey;
/**
* The public information of an RSA key pair.
*/
struct GNUNET_CRYPTO_RsaPublicKey;
/**
* Constant-size pre-secret for blinding key generation.
*/
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
*/
struct GNUNET_CRYPTO_RsaSignature;
/**
* Create a new private key. Caller must free return value.
*
* @param len length of the key in bits (i.e. 2048)
* @return fresh private key
*/
struct GNUNET_CRYPTO_RsaPrivateKey *
GNUNET_CRYPTO_rsa_private_key_create (unsigned int len);
/**
* Free memory occupied by the private key.
*
* @param key pointer to the memory to free
*/
void
GNUNET_CRYPTO_rsa_private_key_free (struct GNUNET_CRYPTO_RsaPrivateKey *key);
/**
* Encode the private key in a format suitable for
* storing it into a file.
*
* @param key the private key
* @param[out] buffer set to a buffer with the encoded key
* @return size of memory allocatedin @a buffer
*/
size_t
GNUNET_CRYPTO_rsa_private_key_encode (const struct GNUNET_CRYPTO_RsaPrivateKey *key,
char **buffer);
/**
* Decode the private key from the data-format back
* to the "normal", internal format.
*
* @param buf the buffer where the private key data is stored
* @param len the length of the data in @a buf
* @return NULL on error
*/
struct GNUNET_CRYPTO_RsaPrivateKey *
GNUNET_CRYPTO_rsa_private_key_decode (const char *buf,
size_t len);
/**
* Duplicate the given private key
*
* @param key the private key to duplicate
* @return the duplicate key; NULL upon error
*/
struct GNUNET_CRYPTO_RsaPrivateKey *
GNUNET_CRYPTO_rsa_private_key_dup (const struct GNUNET_CRYPTO_RsaPrivateKey *key);
/**
* Extract the public key of the given private key.
*
* @param priv the private key
* @retur NULL on error, otherwise the public key
*/
struct GNUNET_CRYPTO_RsaPublicKey *
GNUNET_CRYPTO_rsa_private_key_get_public (const struct GNUNET_CRYPTO_RsaPrivateKey *priv);
/**
* Compute hash over the public key.
*
* @param key public key to hash
* @param hc where to store the hash code
*/
void
GNUNET_CRYPTO_rsa_public_key_hash (const struct GNUNET_CRYPTO_RsaPublicKey *key,
struct GNUNET_HashCode *hc);
/**
* Obtain the length of the RSA key in bits.
*
* @param key the public key to introspect
* @return length of the key in bits
*/
unsigned int
GNUNET_CRYPTO_rsa_public_key_len (const struct GNUNET_CRYPTO_RsaPublicKey *key);
/**
* Free memory occupied by the public key.
*
* @param key pointer to the memory to free
*/
void
GNUNET_CRYPTO_rsa_public_key_free (struct GNUNET_CRYPTO_RsaPublicKey *key);
/**
* Encode the public key in a format suitable for
* storing it into a file.
*
* @param key the private 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_public_key_encode (const struct GNUNET_CRYPTO_RsaPublicKey *key,
char **buffer);
/**
* Decode the public 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_RsaPublicKey *
GNUNET_CRYPTO_rsa_public_key_decode (const char *buf,
size_t len);
/**
* Duplicate the given public key
*
* @param key the public key to duplicate
* @return the duplicate key; NULL upon error
*/
struct GNUNET_CRYPTO_RsaPublicKey *
GNUNET_CRYPTO_rsa_public_key_dup (const struct GNUNET_CRYPTO_RsaPublicKey *key);
/**
* Compare the values of two signatures.
*
* @param s1 one signature
* @param s2 the other signature
* @return 0 if the two are equal
*/
int
GNUNET_CRYPTO_rsa_signature_cmp (struct GNUNET_CRYPTO_RsaSignature *s1,
struct GNUNET_CRYPTO_RsaSignature *s2);
/**
* Compare the values of two private keys.
*
* @param p1 one private key
* @param p2 the other private key
* @return 0 if the two are equal
*/
int
GNUNET_CRYPTO_rsa_private_key_cmp (struct GNUNET_CRYPTO_RsaPrivateKey *p1,
struct GNUNET_CRYPTO_RsaPrivateKey *p2);
/**
* Compare the values of two public keys.
*
* @param p1 one public key
* @param p2 the other public key
* @return 0 if the two are equal
*/
int
GNUNET_CRYPTO_rsa_public_key_cmp (struct GNUNET_CRYPTO_RsaPublicKey *p1,
struct GNUNET_CRYPTO_RsaPublicKey *p2);
/**
* 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] 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
*/
int
GNUNET_CRYPTO_rsa_blind (const struct GNUNET_HashCode *hash,
const struct GNUNET_CRYPTO_RsaBlindingKeySecret *bks,
struct GNUNET_CRYPTO_RsaPublicKey *pkey,
char **buf,
size_t *buf_size);
/**
* Sign a blinded value, which must be a full domain hash of a message.
*
* @param key private key to use for the signing
* @param msg the (blinded) message to sign
* @param msg_len number of bytes in @a msg to sign
* @return NULL on error, signature on success
*/
struct GNUNET_CRYPTO_RsaSignature *
GNUNET_CRYPTO_rsa_sign_blinded (const struct GNUNET_CRYPTO_RsaPrivateKey *key,
const void *msg,
size_t msg_len);
/**
* Create and sign a full domain hash of a message.
*
* @param key private key to use for the signing
* @param hash the hash of the message to sign
* @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,
const struct GNUNET_HashCode *hash);
/**
* Free memory occupied by signature.
*
* @param sig memory to free
*/
void
GNUNET_CRYPTO_rsa_signature_free (struct GNUNET_CRYPTO_RsaSignature *sig);
/**
* Encode the given signature in a format suitable for storing it into a file.
*
* @param sig the signature
* @param[out] buffer set to a buffer with the encoded key
* @return size of memory allocated in @a buffer
*/
size_t
GNUNET_CRYPTO_rsa_signature_encode (const struct GNUNET_CRYPTO_RsaSignature *sig,
char **buffer);
/**
* Decode the signature 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_RsaSignature *
GNUNET_CRYPTO_rsa_signature_decode (const char *buf,
size_t len);
/**
* Duplicate the given rsa signature
*
* @param sig the signature to duplicate
* @return the duplicate key; NULL upon error
*/
struct GNUNET_CRYPTO_RsaSignature *
GNUNET_CRYPTO_rsa_signature_dup (const struct GNUNET_CRYPTO_RsaSignature *sig);
/**
* Unblind a blind-signed signature. The signature should have been generated
* with #GNUNET_CRYPTO_rsa_sign() using a hash that was blinded with
* #GNUNET_CRYPTO_rsa_blind().
*
* @param sig the signature made on the blinded 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 if RSA key is bad or malicious.
*/
struct GNUNET_CRYPTO_RsaSignature *
GNUNET_CRYPTO_rsa_unblind (const struct GNUNET_CRYPTO_RsaSignature *sig,
const struct GNUNET_CRYPTO_RsaBlindingKeySecret *bks,
struct GNUNET_CRYPTO_RsaPublicKey *pkey);
/**
* Verify whether the given hash corresponds to the given signature and the
* signature is valid with respect to the given public key.
*
* @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_YES if ok, #GNUNET_NO if RSA key is malicious, #GNUNET_SYSERR if signature
*/
int
GNUNET_CRYPTO_rsa_verify (const struct GNUNET_HashCode *hash,
const struct GNUNET_CRYPTO_RsaSignature *sig,
const struct GNUNET_CRYPTO_RsaPublicKey *public_key);
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif
/* ifndef GNUNET_CRYPTO_LIB_H */
#endif
/* end of gnunet_crypto_lib.h */