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22 * @file fs/fs_publish_ublock.c
23 * @brief publish a UBLOCK in GNUnet
24 * @see https://gnunet.org/encoding and #2564
25 * @author Krista Bennett
26 * @author Christian Grothoff
29 #include "gnunet_constants.h"
30 #include "gnunet_signatures.h"
31 #include "fs_publish_ublock.h"
37 * Derive the key for symmetric encryption/decryption from
38 * the public key and the label.
40 * @param skey where to store symmetric key
41 * @param iv where to store the IV
42 * @param label label to use for key derivation
43 * @param pub public key to use for key derivation
46 derive_ublock_encryption_key (struct GNUNET_CRYPTO_SymmetricSessionKey *skey,
47 struct GNUNET_CRYPTO_SymmetricInitializationVector *iv,
49 const struct GNUNET_CRYPTO_EcdsaPublicKey *pub)
51 struct GNUNET_HashCode key;
53 /* derive key from 'label' and public key of the namespace */
54 GNUNET_assert (GNUNET_YES ==
55 GNUNET_CRYPTO_kdf (&key, sizeof (key),
56 "UBLOCK-ENC", strlen ("UBLOCK-ENC"),
57 label, strlen (label),
60 GNUNET_CRYPTO_hash_to_aes_key (&key, skey, iv);
65 * Decrypt the given UBlock, storing the result in output.
67 * @param input input data
68 * @param input_len number of bytes in @a input
69 * @param ns public key under which the UBlock was stored
70 * @param label label under which the UBlock was stored
71 * @param output where to write the result, has input_len bytes
74 GNUNET_FS_ublock_decrypt_ (const void *input,
76 const struct GNUNET_CRYPTO_EcdsaPublicKey *ns,
80 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
81 struct GNUNET_CRYPTO_SymmetricSessionKey skey;
83 derive_ublock_encryption_key (&skey, &iv,
85 GNUNET_CRYPTO_symmetric_decrypt (input, input_len,
92 * Context for 'ublock_put_cont'.
94 struct GNUNET_FS_PublishUblockContext
98 * Function to call when done.
100 GNUNET_FS_UBlockContinuation cont;
108 * Handle for active datastore operation.
110 struct GNUNET_DATASTORE_QueueEntry *qre;
113 * Task to run continuation asynchronously.
115 struct GNUNET_SCHEDULER_Task * task;
121 * Continuation of #GNUNET_FS_publish_ublock_().
123 * @param cls closure of type "struct GNUNET_FS_PublishUblockContext*"
124 * @param success #GNUNET_SYSERR on failure (including timeout/queue drop)
125 * #GNUNET_NO if content was already there
126 * #GNUNET_YES (or other positive value) on success
127 * @param min_expiration minimum expiration time required for 0-priority content to be stored
128 * by the datacache at this time, zero for unknown, forever if we have no
129 * space for 0-priority content
130 * @param msg NULL on success, otherwise an error message
133 ublock_put_cont (void *cls,
135 struct GNUNET_TIME_Absolute min_expiration,
138 struct GNUNET_FS_PublishUblockContext *uc = cls;
141 uc->cont (uc->cont_cls, msg);
147 * Run the continuation.
149 * @param cls the `struct GNUNET_FS_PublishUblockContext *`
154 struct GNUNET_FS_PublishUblockContext *uc = cls;
157 uc->cont (uc->cont_cls, NULL);
165 * @param h handle to the file sharing subsystem
166 * @param dsh datastore handle to use for storage operation
167 * @param label identifier to use
168 * @param ulabel update label to use, may be an empty string for none
169 * @param ns namespace to publish in
170 * @param meta metadata to use
171 * @param uri URI to refer to in the UBlock
172 * @param bo per-block options
173 * @param options publication options
174 * @param cont continuation
175 * @param cont_cls closure for @a cont
176 * @return NULL on error (@a cont will still be called)
178 struct GNUNET_FS_PublishUblockContext *
179 GNUNET_FS_publish_ublock_ (struct GNUNET_FS_Handle *h,
180 struct GNUNET_DATASTORE_Handle *dsh,
183 const struct GNUNET_CRYPTO_EcdsaPrivateKey *ns,
184 const struct GNUNET_CONTAINER_MetaData *meta,
185 const struct GNUNET_FS_Uri *uri,
186 const struct GNUNET_FS_BlockOptions *bo,
187 enum GNUNET_FS_PublishOptions options,
188 GNUNET_FS_UBlockContinuation cont, void *cont_cls)
190 struct GNUNET_FS_PublishUblockContext *uc;
191 struct GNUNET_HashCode query;
192 struct GNUNET_CRYPTO_SymmetricInitializationVector iv;
193 struct GNUNET_CRYPTO_SymmetricSessionKey skey;
194 struct GNUNET_CRYPTO_EcdsaPrivateKey *nsd;
195 struct GNUNET_CRYPTO_EcdsaPublicKey pub;
203 struct UBlock *ub_plain;
204 struct UBlock *ub_enc;
206 /* compute ublock to publish */
210 mdsize = GNUNET_CONTAINER_meta_data_get_serialized_size (meta);
211 GNUNET_assert (mdsize >= 0);
212 uris = GNUNET_FS_uri_to_string (uri);
213 slen = strlen (uris) + 1;
217 ulen = strlen (ulabel) + 1;
218 size = mdsize + sizeof (struct UBlock) + slen + ulen;
219 if (size > MAX_UBLOCK_SIZE)
221 size = MAX_UBLOCK_SIZE;
222 mdsize = size - sizeof (struct UBlock) - (slen + ulen);
224 ub_plain = GNUNET_malloc (size);
225 kbe = (char *) &ub_plain[1];
227 memcpy (kbe, ulabel, ulen);
229 memcpy (kbe, uris, slen);
235 GNUNET_CONTAINER_meta_data_serialize (meta, &sptr, mdsize,
236 GNUNET_CONTAINER_META_DATA_SERIALIZE_PART);
240 GNUNET_free (ub_plain);
241 cont (cont_cls, _("Internal error."));
244 size = sizeof (struct UBlock) + slen + mdsize + ulen;
246 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
247 "Publishing under identifier `%s'\n",
249 /* get public key of the namespace */
250 GNUNET_CRYPTO_ecdsa_key_get_public (ns,
252 derive_ublock_encryption_key (&skey, &iv,
256 ub_enc = GNUNET_malloc (size);
257 GNUNET_CRYPTO_symmetric_encrypt (&ub_plain[1],
258 ulen + slen + mdsize,
261 GNUNET_free (ub_plain);
262 ub_enc->purpose.size = htonl (ulen + slen + mdsize +
263 sizeof (struct UBlock)
264 - sizeof (struct GNUNET_CRYPTO_EcdsaSignature));
265 ub_enc->purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_FS_UBLOCK);
267 /* derive signing-key from 'label' and public key of the namespace */
268 nsd = GNUNET_CRYPTO_ecdsa_private_key_derive (ns, label, "fs-ublock");
269 GNUNET_CRYPTO_ecdsa_key_get_public (nsd,
270 &ub_enc->verification_key);
271 GNUNET_assert (GNUNET_OK ==
272 GNUNET_CRYPTO_ecdsa_sign (nsd,
274 &ub_enc->signature));
275 GNUNET_CRYPTO_hash (&ub_enc->verification_key,
276 sizeof (ub_enc->verification_key),
280 uc = GNUNET_new (struct GNUNET_FS_PublishUblockContext);
282 uc->cont_cls = cont_cls;
286 GNUNET_DATASTORE_put (dsh,
289 ulen + slen + mdsize + sizeof (struct UBlock),
291 GNUNET_BLOCK_TYPE_FS_UBLOCK,
292 bo->content_priority,
294 bo->replication_level,
297 &ublock_put_cont, uc);
301 uc->task = GNUNET_SCHEDULER_add_now (&run_cont,
309 * Abort UBlock publishing operation.
311 * @param uc operation to abort.
314 GNUNET_FS_publish_ublock_cancel_ (struct GNUNET_FS_PublishUblockContext *uc)
317 GNUNET_DATASTORE_cancel (uc->qre);
318 if (NULL != uc->task)
319 GNUNET_SCHEDULER_cancel (uc->task);
323 /* end of fs_publish_ublock.c */