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22 * @file include/gnunet_crypto_lib.h
23 * @brief cryptographic primitives for GNUnet
25 * @author Christian Grothoff
26 * @author Krista Bennett
27 * @author Gerd Knorr <kraxel@bytesex.org>
28 * @author Ioana Patrascu
29 * @author Tzvetan Horozov
32 #ifndef GNUNET_CRYPTO_LIB_H
33 #define GNUNET_CRYPTO_LIB_H
38 #if 0 /* keep Emacsens' auto-indent happy */
43 #include "gnunet_common.h"
44 #include "gnunet_scheduler_lib.h"
47 * Desired quality level for cryptographic operations.
49 enum GNUNET_CRYPTO_Quality
52 * No good quality of the operation is needed (i.e.,
53 * random numbers can be pseudo-random).
55 GNUNET_CRYPTO_QUALITY_WEAK,
58 * High-quality operations are desired.
60 GNUNET_CRYPTO_QUALITY_STRONG,
63 * Randomness for IVs etc. is required.
65 GNUNET_CRYPTO_QUALITY_NONCE
70 * @brief length of the sessionkey in bytes (256 BIT sessionkey)
72 #define GNUNET_CRYPTO_AES_KEY_LENGTH (256/8)
76 * @brief Length of RSA encrypted data (2048 bit)
78 * We currently do not handle encryption of data
79 * that can not be done in a single call to the
80 * RSA methods (read: large chunks of data).
81 * We should never need that, as we can use
82 * the GNUNET_CRYPTO_hash for larger pieces of data for signing,
83 * and for encryption, we only need to encode sessionkeys!
85 #define GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH 256
89 * Length of an RSA KEY (n,e,len), 2048 bit (=256 octests) key n, 2 byte e
91 #define GNUNET_CRYPTO_RSA_KEY_LENGTH 258
95 * Length of a hash value
97 #define GNUNET_CRYPTO_HASH_LENGTH 512/8
100 * The private information of an RSA key pair.
102 struct GNUNET_CRYPTO_RsaPrivateKey;
104 GNUNET_NETWORK_STRUCT_BEGIN
107 * GNUnet mandates a certain format for the encoding
108 * of private RSA key information that is provided
109 * by the RSA implementations. This format is used
110 * to serialize a private RSA key (typically when
111 * writing it to disk).
113 struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded
116 * Total size of the structure, in bytes, in big-endian!
118 uint16_t len GNUNET_PACKED;
119 uint16_t sizen GNUNET_PACKED; /* in big-endian! */
120 uint16_t sizee GNUNET_PACKED; /* in big-endian! */
121 uint16_t sized GNUNET_PACKED; /* in big-endian! */
122 uint16_t sizep GNUNET_PACKED; /* in big-endian! */
123 uint16_t sizeq GNUNET_PACKED; /* in big-endian! */
124 uint16_t sizedmp1 GNUNET_PACKED; /* in big-endian! */
125 uint16_t sizedmq1 GNUNET_PACKED; /* in big-endian! */
126 /* followed by the actual values */
128 GNUNET_NETWORK_STRUCT_END
132 * @brief 0-terminated ASCII encoding of a struct GNUNET_HashCode.
134 struct GNUNET_CRYPTO_HashAsciiEncoded
136 unsigned char encoding[104];
141 * @brief 0-terminated ASCII encoding of a 'struct GNUNET_ShortHashCode'.
143 struct GNUNET_CRYPTO_ShortHashAsciiEncoded
145 unsigned char short_encoding[53];
151 * @brief an RSA signature
153 struct GNUNET_CRYPTO_RsaSignature
155 unsigned char sig[GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH];
159 GNUNET_NETWORK_STRUCT_BEGIN
162 * @brief header of what an RSA signature signs
163 * this must be followed by "size - 8" bytes of
164 * the actual signed data
166 struct GNUNET_CRYPTO_RsaSignaturePurpose
169 * How many bytes does this signature sign?
170 * (including this purpose header); in network
173 uint32_t size GNUNET_PACKED;
176 * What does this signature vouch for? This
177 * must contain a GNUNET_SIGNATURE_PURPOSE_XXX
178 * constant (from gnunet_signatures.h). In
179 * network byte order!
181 uint32_t purpose GNUNET_PACKED;
187 * @brief A public key.
189 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
192 * In big-endian, must be GNUNET_CRYPTO_RSA_KEY_LENGTH+4
194 uint16_t len GNUNET_PACKED;
197 * Size of n in key; in big-endian!
199 uint16_t sizen GNUNET_PACKED;
202 * The key itself, contains n followed by e.
204 unsigned char key[GNUNET_CRYPTO_RSA_KEY_LENGTH];
207 * Padding (must be 0)
209 uint16_t padding GNUNET_PACKED;
214 * RSA Encrypted data.
216 struct GNUNET_CRYPTO_RsaEncryptedData
218 unsigned char encoding[GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH];
223 * @brief type for session keys
225 struct GNUNET_CRYPTO_AesSessionKey
230 unsigned char key[GNUNET_CRYPTO_AES_KEY_LENGTH];
235 uint32_t crc32 GNUNET_PACKED;
237 GNUNET_NETWORK_STRUCT_END
240 * @brief IV for sym cipher
242 * NOTE: must be smaller (!) in size than the
243 * struct GNUNET_HashCode.
245 struct GNUNET_CRYPTO_AesInitializationVector
247 unsigned char iv[GNUNET_CRYPTO_AES_KEY_LENGTH / 2];
252 * @brief type for (message) authentication keys
254 struct GNUNET_CRYPTO_AuthKey
256 unsigned char key[GNUNET_CRYPTO_HASH_LENGTH];
260 /* **************** Functions and Macros ************* */
263 * Seed a weak random generator. Only GNUNET_CRYPTO_QUALITY_WEAK-mode generator
266 * @param seed the seed to use
269 GNUNET_CRYPTO_seed_weak_random (int32_t seed);
273 * Perform an incremental step in a CRC16 (for TCP/IP) calculation.
275 * @param sum current sum, initially 0
276 * @param buf buffer to calculate CRC over (must be 16-bit aligned)
277 * @param len number of bytes in hdr, must be multiple of 2
278 * @return updated crc sum (must be subjected to GNUNET_CRYPTO_crc16_finish to get actual crc16)
281 GNUNET_CRYPTO_crc16_step (uint32_t sum, const void *buf, size_t len);
285 * Convert results from GNUNET_CRYPTO_crc16_step to final crc16.
287 * @param sum cummulative sum
288 * @return crc16 value
291 GNUNET_CRYPTO_crc16_finish (uint32_t sum);
295 * Calculate the checksum of a buffer in one step.
297 * @param buf buffer to calculate CRC over (must be 16-bit aligned)
298 * @param len number of bytes in hdr, must be multiple of 2
299 * @return crc16 value
302 GNUNET_CRYPTO_crc16_n (const void *buf, size_t len);
306 * Compute the CRC32 checksum for the first len
307 * bytes of the buffer.
309 * @param buf the data over which we're taking the CRC
310 * @param len the length of the buffer in bytes
311 * @return the resulting CRC32 checksum
314 GNUNET_CRYPTO_crc32_n (const void *buf, size_t len);
318 * Produce a random value.
320 * @param mode desired quality of the random number
321 * @param i the upper limit (exclusive) for the random number
322 * @return a random value in the interval [0,i) (exclusive).
325 GNUNET_CRYPTO_random_u32 (enum GNUNET_CRYPTO_Quality mode, uint32_t i);
329 * Random on unsigned 64-bit values.
331 * @param mode desired quality of the random number
332 * @param max value returned will be in range [0,max) (exclusive)
333 * @return random 64-bit number
336 GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max);
340 * Get an array with a random permutation of the
342 * @param mode GNUNET_CRYPTO_QUALITY_STRONG if the strong (but expensive) PRNG should be used, GNUNET_CRYPTO_QUALITY_WEAK otherwise
343 * @param n the size of the array
344 * @return the permutation array (allocated from heap)
347 GNUNET_CRYPTO_random_permute (enum GNUNET_CRYPTO_Quality mode, unsigned int n);
351 * Create a new Session key.
353 * @param key key to initialize
356 GNUNET_CRYPTO_aes_create_session_key (struct GNUNET_CRYPTO_AesSessionKey *key);
360 * Check that a new session key is well-formed.
362 * @param key key to check
363 * @return GNUNET_OK if the key is valid
366 GNUNET_CRYPTO_aes_check_session_key (const struct GNUNET_CRYPTO_AesSessionKey
371 * Encrypt a block with the public key of another
372 * host that uses the same cyper.
374 * @param block the block to encrypt
375 * @param len the size of the block
376 * @param sessionkey the key used to encrypt
377 * @param iv the initialization vector to use, use INITVALUE
379 * @return the size of the encrypted block, -1 for errors
382 GNUNET_CRYPTO_aes_encrypt (const void *block, size_t len,
383 const struct GNUNET_CRYPTO_AesSessionKey *sessionkey,
384 const struct GNUNET_CRYPTO_AesInitializationVector
389 * Decrypt a given block with the sessionkey.
391 * @param block the data to decrypt, encoded as returned by encrypt
392 * @param size how big is the block?
393 * @param sessionkey the key used to decrypt
394 * @param iv the initialization vector to use
395 * @param result address to store the result at
396 * @return -1 on failure, size of decrypted block on success
399 GNUNET_CRYPTO_aes_decrypt (const void *block, size_t size,
400 const struct GNUNET_CRYPTO_AesSessionKey *sessionkey,
401 const struct GNUNET_CRYPTO_AesInitializationVector
406 * @brief Derive an IV
407 * @param iv initialization vector
408 * @param skey session key
409 * @param salt salt for the derivation
410 * @param salt_len size of the salt
411 * @param ... pairs of void * & size_t for context chunks, terminated by NULL
414 GNUNET_CRYPTO_aes_derive_iv (struct GNUNET_CRYPTO_AesInitializationVector *iv,
415 const struct GNUNET_CRYPTO_AesSessionKey *skey,
416 const void *salt, size_t salt_len, ...);
420 * @brief Derive an IV
421 * @param iv initialization vector
422 * @param skey session key
423 * @param salt salt for the derivation
424 * @param salt_len size of the salt
425 * @param argp pairs of void * & size_t for context chunks, terminated by NULL
428 GNUNET_CRYPTO_aes_derive_iv_v (struct GNUNET_CRYPTO_AesInitializationVector *iv,
429 const struct GNUNET_CRYPTO_AesSessionKey *skey,
430 const void *salt, size_t salt_len, va_list argp);
434 * Convert hash to ASCII encoding.
435 * @param block the hash code
436 * @param result where to store the encoding (struct GNUNET_CRYPTO_HashAsciiEncoded can be
437 * safely cast to char*, a '\\0' termination is set).
440 GNUNET_CRYPTO_hash_to_enc (const struct GNUNET_HashCode * block,
441 struct GNUNET_CRYPTO_HashAsciiEncoded *result);
445 * Convert short hash to ASCII encoding.
447 * @param block the hash code
448 * @param result where to store the encoding (struct GNUNET_CRYPTO_ShortHashAsciiEncoded can be
449 * safely cast to char*, a '\\0' termination is set).
452 GNUNET_CRYPTO_short_hash_to_enc (const struct GNUNET_CRYPTO_ShortHashCode * block,
453 struct GNUNET_CRYPTO_ShortHashAsciiEncoded *result);
457 * Convert ASCII encoding back to a 'struct GNUNET_HashCode'
459 * @param enc the encoding
460 * @param enclen number of characters in 'enc' (without 0-terminator, which can be missing)
461 * @param result where to store the GNUNET_CRYPTO_hash code
462 * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
465 GNUNET_CRYPTO_hash_from_string2 (const char *enc, size_t enclen,
466 struct GNUNET_HashCode * result);
470 * Convert ASCII encoding back to a 'struct GNUNET_CRYPTO_ShortHash'
472 * @param enc the encoding
473 * @param enclen number of characters in 'enc' (without 0-terminator, which can be missing)
474 * @param result where to store the GNUNET_CRYPTO_hash code
475 * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
478 GNUNET_CRYPTO_short_hash_from_string2 (const char *enc, size_t enclen,
479 struct GNUNET_CRYPTO_ShortHashCode * result);
483 * Convert ASCII encoding back to struct GNUNET_HashCode
485 * @param enc the encoding
486 * @param result where to store the hash code
487 * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
489 #define GNUNET_CRYPTO_hash_from_string(enc, result) \
490 GNUNET_CRYPTO_hash_from_string2 (enc, strlen(enc), result)
494 * Convert ASCII encoding back to a 'struct GNUNET_CRYPTO_ShortHash'
496 * @param enc the encoding
497 * @param result where to store the GNUNET_CRYPTO_ShortHash
498 * @return GNUNET_OK on success, GNUNET_SYSERR if result has the wrong encoding
500 #define GNUNET_CRYPTO_short_hash_from_string(enc, result) \
501 GNUNET_CRYPTO_short_hash_from_string2 (enc, strlen(enc), result)
505 * Compare function for ShortHashCodes, producing a total ordering
508 * @param h1 some hash code
509 * @param h2 some hash code
510 * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2.
513 GNUNET_CRYPTO_short_hash_cmp (const struct GNUNET_CRYPTO_ShortHashCode * h1,
514 const struct GNUNET_CRYPTO_ShortHashCode * h2);
517 * Compute the distance between 2 hashcodes.
518 * The computation must be fast, not involve
519 * a.a or a.e (they're used elsewhere), and
520 * be somewhat consistent. And of course, the
521 * result should be a positive number.
523 * @param a some hash code
524 * @param b some hash code
525 * @return number between 0 and UINT32_MAX
528 GNUNET_CRYPTO_hash_distance_u32 (const struct GNUNET_HashCode * a,
529 const struct GNUNET_HashCode * b);
533 * Compute hash of a given block.
535 * @param block the data to hash
536 * @param size size of the block
537 * @param ret pointer to where to write the hashcode
540 GNUNET_CRYPTO_hash (const void *block, size_t size, struct GNUNET_HashCode * ret);
544 * Compute short (256-bit) hash of a given block.
546 * @param block the data to hash
547 * @param size size of the block
548 * @param ret pointer to where to write the hashcode
551 GNUNET_CRYPTO_short_hash (const void *block, size_t size,
552 struct GNUNET_CRYPTO_ShortHashCode * ret);
556 * Double short (256-bit) hash to create a long hash.
558 * @param sh short hash to double
559 * @param dh where to store the (doubled) long hash (not really a hash)
562 GNUNET_CRYPTO_short_hash_double (const struct GNUNET_CRYPTO_ShortHashCode *sh,
563 struct GNUNET_HashCode *dh);
567 * Truncate doubled short hash back to a short hash.
569 * @param dh doubled short hash to reduce again
570 * @param sh where to store the short hash
571 * @return GNUNET_OK on success, GNUNET_SYSERR if this was not a
575 GNUNET_CRYPTO_short_hash_from_truncation (const struct GNUNET_HashCode *dh,
576 struct GNUNET_CRYPTO_ShortHashCode *sh);
580 * Calculate HMAC of a message (RFC 2104)
582 * @param key secret key
583 * @param plaintext input plaintext
584 * @param plaintext_len length of plaintext
585 * @param hmac where to store the hmac
588 GNUNET_CRYPTO_hmac (const struct GNUNET_CRYPTO_AuthKey *key,
589 const void *plaintext, size_t plaintext_len,
590 struct GNUNET_HashCode * hmac);
594 * Function called once the hash computation over the
595 * specified file has completed.
598 * @param res resulting hash, NULL on error
600 typedef void (*GNUNET_CRYPTO_HashCompletedCallback) (void *cls,
601 const struct GNUNET_HashCode *
606 * Handle to file hashing operation.
608 struct GNUNET_CRYPTO_FileHashContext;
611 * Compute the hash of an entire file.
613 * @param priority scheduling priority to use
614 * @param filename name of file to hash
615 * @param blocksize number of bytes to process in one task
616 * @param callback function to call upon completion
617 * @param callback_cls closure for callback
618 * @return NULL on (immediate) errror
620 struct GNUNET_CRYPTO_FileHashContext *
621 GNUNET_CRYPTO_hash_file (enum GNUNET_SCHEDULER_Priority priority,
622 const char *filename, size_t blocksize,
623 GNUNET_CRYPTO_HashCompletedCallback callback,
628 * Cancel a file hashing operation.
630 * @param fhc operation to cancel (callback must not yet have been invoked)
633 GNUNET_CRYPTO_hash_file_cancel (struct GNUNET_CRYPTO_FileHashContext *fhc);
637 * Create a random hash code.
639 * @param mode desired quality level
640 * @param result hash code that is randomized
643 GNUNET_CRYPTO_hash_create_random (enum GNUNET_CRYPTO_Quality mode,
644 struct GNUNET_HashCode * result);
648 * compute result(delta) = b - a
650 * @param a some hash code
651 * @param b some hash code
652 * @param result set to b - a
655 GNUNET_CRYPTO_hash_difference (const struct GNUNET_HashCode * a,
656 const struct GNUNET_HashCode * b,
657 struct GNUNET_HashCode * result);
661 * compute result(b) = a + delta
663 * @param a some hash code
664 * @param delta some hash code
665 * @param result set to a + delta
668 GNUNET_CRYPTO_hash_sum (const struct GNUNET_HashCode * a,
669 const struct GNUNET_HashCode * delta,
670 struct GNUNET_HashCode * result);
674 * compute result = a ^ b
676 * @param a some hash code
677 * @param b some hash code
678 * @param result set to a ^ b
681 GNUNET_CRYPTO_hash_xor (const struct GNUNET_HashCode * a, const struct GNUNET_HashCode * b,
682 struct GNUNET_HashCode * result);
686 * Convert a hashcode into a key.
688 * @param hc hash code that serves to generate the key
689 * @param skey set to a valid session key
690 * @param iv set to a valid initialization vector
693 GNUNET_CRYPTO_hash_to_aes_key (const struct GNUNET_HashCode * hc,
694 struct GNUNET_CRYPTO_AesSessionKey *skey,
695 struct GNUNET_CRYPTO_AesInitializationVector
700 * Obtain a bit from a hashcode.
702 * @param code the GNUNET_CRYPTO_hash to index bit-wise
703 * @param bit index into the hashcode, [0...159]
704 * @return Bit \a bit from hashcode \a code, -1 for invalid index
707 GNUNET_CRYPTO_hash_get_bit (const struct GNUNET_HashCode * code, unsigned int bit);
710 * Determine how many low order bits match in two
711 * struct GNUNET_HashCodes. i.e. - 010011 and 011111 share
712 * the first two lowest order bits, and therefore the
713 * return value is two (NOT XOR distance, nor how many
714 * bits match absolutely!).
716 * @param first the first hashcode
717 * @param second the hashcode to compare first to
719 * @return the number of bits that match
722 GNUNET_CRYPTO_hash_matching_bits (const struct GNUNET_HashCode * first,
723 const struct GNUNET_HashCode * second);
727 * Compare function for HashCodes, producing a total ordering
730 * @param h1 some hash code
731 * @param h2 some hash code
732 * @return 1 if h1 > h2, -1 if h1 < h2 and 0 if h1 == h2.
735 GNUNET_CRYPTO_hash_cmp (const struct GNUNET_HashCode * h1, const struct GNUNET_HashCode * h2);
739 * Find out which of the two GNUNET_CRYPTO_hash codes is closer to target
740 * in the XOR metric (Kademlia).
742 * @param h1 some hash code
743 * @param h2 some hash code
744 * @param target some hash code
745 * @return -1 if h1 is closer, 1 if h2 is closer and 0 if h1==h2.
748 GNUNET_CRYPTO_hash_xorcmp (const struct GNUNET_HashCode * h1,
749 const struct GNUNET_HashCode * h2,
750 const struct GNUNET_HashCode * target);
754 * @brief Derive an authentication key
755 * @param key authentication key
756 * @param rkey root key
758 * @param salt_len size of the salt
759 * @param argp pair of void * & size_t for context chunks, terminated by NULL
762 GNUNET_CRYPTO_hmac_derive_key_v (struct GNUNET_CRYPTO_AuthKey *key,
763 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
764 const void *salt, size_t salt_len,
769 * @brief Derive an authentication key
770 * @param key authentication key
771 * @param rkey root key
773 * @param salt_len size of the salt
774 * @param ... pair of void * & size_t for context chunks, terminated by NULL
777 GNUNET_CRYPTO_hmac_derive_key (struct GNUNET_CRYPTO_AuthKey *key,
778 const struct GNUNET_CRYPTO_AesSessionKey *rkey,
779 const void *salt, size_t salt_len, ...);
783 * @param result buffer for the derived key, allocated by caller
784 * @param out_len desired length of the derived key
785 * @param xtr_algo hash algorithm for the extraction phase, GCRY_MD_...
786 * @param prf_algo hash algorithm for the expansion phase, GCRY_MD_...
788 * @param xts_len length of xts
789 * @param skm source key material
790 * @param skm_len length of skm
791 * @return GNUNET_YES on success
794 GNUNET_CRYPTO_hkdf (void *result, size_t out_len, int xtr_algo, int prf_algo,
795 const void *xts, size_t xts_len, const void *skm,
796 size_t skm_len, ...);
801 * @param result buffer for the derived key, allocated by caller
802 * @param out_len desired length of the derived key
803 * @param xtr_algo hash algorithm for the extraction phase, GCRY_MD_...
804 * @param prf_algo hash algorithm for the expansion phase, GCRY_MD_...
806 * @param xts_len length of xts
807 * @param skm source key material
808 * @param skm_len length of skm
809 * @param argp va_list of void * & size_t pairs for context chunks
810 * @return GNUNET_YES on success
813 GNUNET_CRYPTO_hkdf_v (void *result, size_t out_len, int xtr_algo, int prf_algo,
814 const void *xts, size_t xts_len, const void *skm,
815 size_t skm_len, va_list argp);
820 * @param result buffer for the derived key, allocated by caller
821 * @param out_len desired length of the derived key
823 * @param xts_len length of xts
824 * @param skm source key material
825 * @param skm_len length of skm
826 * @param argp va_list of void * & size_t pairs for context chunks
827 * @return GNUNET_YES on success
830 GNUNET_CRYPTO_kdf_v (void *result, size_t out_len, const void *xts,
831 size_t xts_len, const void *skm, size_t skm_len,
837 * @param result buffer for the derived key, allocated by caller
838 * @param out_len desired length of the derived key
840 * @param xts_len length of xts
841 * @param skm source key material
842 * @param skm_len length of skm
843 * @param ... void * & size_t pairs for context chunks
844 * @return GNUNET_YES on success
847 GNUNET_CRYPTO_kdf (void *result, size_t out_len, const void *xts,
848 size_t xts_len, const void *skm, size_t skm_len, ...);
852 * Convert a public key to a string.
854 * @param pub key to convert
855 * @return string representing 'pub'
858 GNUNET_CRYPTO_rsa_public_key_to_string (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pub);
862 * Convert a string representing a public key to a public key.
864 * @param enc encoded public key
865 * @param enclen number of bytes in enc (without 0-terminator)
866 * @param pub where to store the public key
867 * @return GNUNET_OK on success
870 GNUNET_CRYPTO_rsa_public_key_from_string (const char *enc,
872 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pub);
876 * Encode the private key in a format suitable for
877 * storing it into a file.
878 * @return encoding of the private key
880 struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded *
881 GNUNET_CRYPTO_rsa_encode_key (const struct GNUNET_CRYPTO_RsaPrivateKey *hostkey);
885 * Decode the private key from the data-format back
886 * to the "normal", internal format.
888 * @param buf the buffer where the private key data is stored
889 * @param len the length of the data in 'buffer'
891 struct GNUNET_CRYPTO_RsaPrivateKey *
892 GNUNET_CRYPTO_rsa_decode_key (const char *buf, uint16_t len);
896 * Create a new private key by reading it from a file. If the
897 * files does not exist, create a new key and write it to the
898 * file. Caller must free return value. Note that this function
899 * can not guarantee that another process might not be trying
900 * the same operation on the same file at the same time.
901 * If the contents of the file
902 * are invalid the old file is deleted and a fresh key is
905 * @param filename name of file to use for storage
906 * @return new private key, NULL on error (for example,
908 * @deprecated use 'GNUNET_CRYPTO_rsa_key_create_start' instead
910 struct GNUNET_CRYPTO_RsaPrivateKey *
911 GNUNET_CRYPTO_rsa_key_create_from_file (const char *filename);
915 * Handle to cancel private key generation.
917 struct GNUNET_CRYPTO_RsaKeyGenerationContext;
921 * Function called upon completion of 'GNUNET_CRYPTO_rsa_key_create_async'.
924 * @param pk NULL on error, otherwise the private key (which must be free'd by the callee)
925 * @param emsg NULL on success, otherwise an error message
927 typedef void (*GNUNET_CRYPTO_RsaKeyCallback)(void *cls,
928 struct GNUNET_CRYPTO_RsaPrivateKey *pk,
933 * Create a new private key by reading it from a file. If the files
934 * does not exist, create a new key and write it to the file. If the
935 * contents of the file are invalid the old file is deleted and a
936 * fresh key is created.
938 * @param filename name of file to use for storage
939 * @param cont function to call when done (or on errors)
940 * @param cont_cls closure for 'cont'
941 * @return handle to abort operation, NULL on fatal errors (cont will not be called if NULL is returned)
943 struct GNUNET_CRYPTO_RsaKeyGenerationContext *
944 GNUNET_CRYPTO_rsa_key_create_start (const char *filename,
945 GNUNET_CRYPTO_RsaKeyCallback cont,
950 * Abort RSA key generation.
952 * @param gc key generation context to abort
955 GNUNET_CRYPTO_rsa_key_create_stop (struct GNUNET_CRYPTO_RsaKeyGenerationContext *gc);
959 * Setup a hostkey file for a peer given the name of the
960 * configuration file (!). This function is used so that
961 * at a later point code can be certain that reading a
962 * hostkey is fast (for example in time-dependent testcases).
964 * @param cfg_name name of the configuration file to use
967 GNUNET_CRYPTO_setup_hostkey (const char *cfg_name);
971 * Deterministically (!) create a private key using only the
972 * given HashCode as input to the PRNG.
974 * @param hc "random" input to PRNG
975 * @return some private key purely dependent on input
977 struct GNUNET_CRYPTO_RsaPrivateKey *
978 GNUNET_CRYPTO_rsa_key_create_from_hash (const struct GNUNET_HashCode * hc);
982 * Free memory occupied by the private key.
983 * @param hostkey pointer to the memory to free
986 GNUNET_CRYPTO_rsa_key_free (struct GNUNET_CRYPTO_RsaPrivateKey *hostkey);
990 * Extract the public key of the host.
992 * @param priv the private key
993 * @param pub where to write the public key
996 GNUNET_CRYPTO_rsa_key_get_public (const struct GNUNET_CRYPTO_RsaPrivateKey
998 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
1003 * Encrypt a block with the public key of another host that uses the
1006 * @param block the block to encrypt
1007 * @param size the size of block
1008 * @param publicKey the encoded public key used to encrypt
1009 * @param target where to store the encrypted block
1010 * @return GNUNET_SYSERR on error, GNUNET_OK if ok
1013 GNUNET_CRYPTO_rsa_encrypt (const void *block, size_t size,
1014 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
1016 struct GNUNET_CRYPTO_RsaEncryptedData *target);
1020 * Decrypt a given block with the hostkey.
1022 * @param key the key to use
1023 * @param block the data to decrypt, encoded as returned by encrypt, not consumed
1024 * @param result pointer to a location where the result can be stored
1025 * @param max how many bytes of a result are expected? Must be exact.
1026 * @return the size of the decrypted block (that is, size) or -1 on error
1029 GNUNET_CRYPTO_rsa_decrypt (const struct GNUNET_CRYPTO_RsaPrivateKey *key,
1030 const struct GNUNET_CRYPTO_RsaEncryptedData *block,
1031 void *result, size_t max);
1035 * Sign a given block.
1037 * @param key private key to use for the signing
1038 * @param purpose what to sign (size, purpose)
1039 * @param sig where to write the signature
1040 * @return GNUNET_SYSERR on error, GNUNET_OK on success
1043 GNUNET_CRYPTO_rsa_sign (const struct GNUNET_CRYPTO_RsaPrivateKey *key,
1044 const struct GNUNET_CRYPTO_RsaSignaturePurpose *purpose,
1045 struct GNUNET_CRYPTO_RsaSignature *sig);
1049 * Verify signature. Note that the caller MUST have already
1050 * checked that "validate->size" bytes are actually available.
1052 * @param purpose what is the purpose that validate should have?
1053 * @param validate block to validate (size, purpose, data)
1054 * @param sig signature that is being validated
1055 * @param publicKey public key of the signer
1056 * @return GNUNET_OK if ok, GNUNET_SYSERR if invalid
1059 GNUNET_CRYPTO_rsa_verify (uint32_t purpose,
1060 const struct GNUNET_CRYPTO_RsaSignaturePurpose
1062 const struct GNUNET_CRYPTO_RsaSignature *sig,
1063 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
1069 * This function should only be called in testcases
1070 * where strong entropy gathering is not desired
1071 * (for example, for hostkey generation).
1074 GNUNET_CRYPTO_random_disable_entropy_gathering (void);
1078 * Check if we are using weak random number generation.
1080 * @return GNUNET_YES if weak number generation is on
1081 * (thus will return YES if 'GNUNET_CRYPTO_random_disable_entropy_gathering'
1082 * was called previously).
1085 GNUNET_CRYPTO_random_is_weak (void);
1088 #if 0 /* keep Emacsens' auto-indent happy */
1096 /* ifndef GNUNET_CRYPTO_LIB_H */
1098 /* end of gnunet_crypto_lib.h */