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Record Protobuf

yamux
John Jones 2017-02-16 20:42:10 -05:00
parent 3aa0d89cb3
commit 897d257b3b
2 changed files with 206 additions and 65 deletions
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10
include/libp2p/record/record.h
View File

@ -3,14 +3,19 @@
struct Libp2pRecord {
// the key that references this record
char* key;
size_t key_size;
// the actual value this record is storing
unsigned char* value;
size_t value_size;
// hash of the author's public key
char* author;
size_t author_size;
// a PKI signature for the key + value + author
unsigned char* signature;
size_t signature_size;
// time the record was received, set by receiver
char* time_received;
size_t time_received_size;
};
/**
@ -47,6 +52,7 @@ int libp2p_record_protobuf_decode(const unsigned char* in, size_t in_size, struc
* @param key the key in the Libp2pRecord
* @param value the value in the Libp2pRecord
* @param vlen the length of value
* @param sign ??
* @param sign true if you want to sign the record
* @returns 0 on success, -1 on error
*/
int libp2p_record_make_put_record (char** record, size_t *rec_size, struct RsaPrivateKey* sk, char* key, char* value, size_t vlen, int sign);
int libp2p_record_make_put_record (char** record, size_t *rec_size, const struct RsaPrivateKey* sk, const char* key, const char* value, size_t vlen, int sign);

261
record/record.c
View File

@ -2,72 +2,207 @@
#include <stdlib.h>
#include "libp2p/crypto/rsa.h"
#include "libp2p/crypto/sha256.h"
#include "libp2p/record/record.h"
#include "protobuf.h"
#include "mh/hashes.h"
#include "mh/multihash.h"
#define RECORD_BUFSIZE 6048
// libp2p_record_make_put_record creates and signs a dht record for the given key/value pair
int libp2p_record_make_put_record (char** record, size_t *rec_size, struct RsaPrivateKey* sk, char* key, char* value, size_t vlen, int sign)
{
char *pkh, *p;
int pkh_len;
size_t len = 0, l;
*record = NULL; *rec_size = 0;
p = malloc(RECORD_BUFSIZE);
if (p) {
memset (p, '\0', len);
if (!protobuf_encode_string (1, WIRETYPE_LENGTH_DELIMITED, key, p, RECORD_BUFSIZE, &l)) {
free (p);
return -1;
}
len += l;
if (!protobuf_encode_length_delimited (2, WIRETYPE_LENGTH_DELIMITED, value, vlen, p+len, RECORD_BUFSIZE-len, &l)) {
free (p);
return -1;
}
len += l;
pkh_len = mh_new_length(MH_H_SHA2_256, sk->public_key_length);
pkh = malloc(pkh_len);
if (!pkh) {
free (p);
return -1;
}
if (mh_new(pkh, MH_H_SHA2_256, sk->public_key_der, sk->public_key_length)) {
free (pkh);
free (p);
return -1;
}
if (!protobuf_encode_length_delimited (3, WIRETYPE_LENGTH_DELIMITED, pkh, pkh_len, p+len, RECORD_BUFSIZE-len, &l)) {
free (pkh);
free (p);
return -1;
}
free (pkh);
len += l;
if (sign) {
char *sign_buf;
size_t sign_length;
if (!libp2p_crypto_rsa_sign (sk, (unsigned char*) p, len, (unsigned char**)sign_buf, &sign_length) ||
!protobuf_encode_string (4, WIRETYPE_LENGTH_DELIMITED, sign_buf, p+len, RECORD_BUFSIZE-len, &l)) {
free(sign_buf);
free (p);
return -1;
}
free(sign_buf);
len += l;
}
}
*record = realloc(p, len); // Reduces memory used for just what is needed.
if (*record) {
*rec_size = len;
} else {
free (p);
return -1;
}
return 0; // sucess.
/**
* Convert a Libp2pRecord into protobuf format
* @param in the Libp2pRecord to convert
* @param buffer where to store the protobuf
* @param max_buffer_size the size of the allocated buffer
* @param bytes_written the size written into buffer
* @returns true(1) on success, otherwise false(0)
*/
int libp2p_record_protobuf_encode(const struct Libp2pRecord* in, unsigned char* buffer, size_t max_buffer_size, size_t* bytes_written) {
// data & data_size
size_t bytes_used = 0;
*bytes_written = 0;
int retVal = 0;
// field 1
retVal = protobuf_encode_length_delimited(1, WIRETYPE_LENGTH_DELIMITED, in->key, in->key_size, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
// field 2
retVal = protobuf_encode_length_delimited(2, WIRETYPE_LENGTH_DELIMITED, in->value, in->value_size, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
// field 3
retVal = protobuf_encode_length_delimited(3, WIRETYPE_LENGTH_DELIMITED, in->author, in->author_size, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
// field 4
retVal = protobuf_encode_length_delimited(4, WIRETYPE_LENGTH_DELIMITED, in->signature, in->signature_size, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
// field 5
retVal = protobuf_encode_length_delimited(5, WIRETYPE_LENGTH_DELIMITED, in->time_received, in->time_received_size, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
return 1;
}
/**
* Generates an estimate of the buffer size needed to encode the struct
* @param in the Libp2pRecord that you want to encode
* @returns the approximate number of bytes required
*/
size_t libp2p_record_protobuf_encode_size(const struct Libp2pRecord* in) {
size_t retVal = 11 + in->key_size;
retVal += 11 + in->value_size;
retVal += 11 + in->author_size;
retVal += 11 + in->signature_size;
retVal += 11 + in->time_received_size;
return retVal;
}
/**
* Convert a protobuf byte array into a Libp2pRecord
* @param in the byte array
* @param in_size the size of the byte array
* @param out a pointer to the new Libp2pRecord
* @returns true(1) on success, otherwise false(0)
*/
int libp2p_record_protobuf_decode(const unsigned char* in, size_t in_size, struct Libp2pRecord** out) {
size_t pos = 0;
int retVal = 0;
if ( (*out = (struct Libp2pRecord*)malloc(sizeof(struct Libp2pRecord))) == NULL)
goto exit;
while(pos < in_size) {
size_t bytes_read = 0;
int field_no;
enum WireType field_type;
if (protobuf_decode_field_and_type(&in[pos], in_size, &field_no, &field_type, &bytes_read) == 0) {
goto exit;
}
pos += bytes_read;
switch(field_no) {
case (1): // key
if (protobuf_decode_length_delimited(&in[pos], in_size - pos, (char**)&((*out)->key),&((*out)->key_size), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
case (2): // value
if (protobuf_decode_length_delimited(&in[pos], in_size - pos, (char**)&((*out)->value), &((*out)->value_size), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
case (3): // author
if (protobuf_decode_length_delimited(&in[pos], in_size - pos, (char**)&((*out)->author), &((*out)->author_size), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
case (4): // signature
if (protobuf_decode_length_delimited(&in[pos], in_size - pos, (char**)&((*out)->signature), &((*out)->signature_size), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
case (5): // time
if (protobuf_decode_length_delimited(&in[pos], in_size - pos, (char**)&((*out)->time_received), &((*out)->time_received_size), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
}
}
retVal = 1;
exit:
if (retVal == 0) {
free(*out);
*out = NULL;
}
return retVal;
}
/**
* This method does all the hard stuff in one step. It fills a Libp2pRecord struct, and converts it into a protobuf
* @param record a pointer to the protobuf results
* @param rec_size the number of bytes used in the area pointed to by record
* @param sk the private key used to sign
* @param key the key in the Libp2pRecord
* @param value the value in the Libp2pRecord
* @param vlen the length of value
* @param sign true(1) if you want to sign the data
* @returns 0 on success, otherwise -1
*/
int libp2p_record_make_put_record (char** record_buf, size_t *rec_size, const struct RsaPrivateKey* sk, const char* key, const char* value, size_t vlen, int sign)
{
int retVal = -1;
size_t bytes_size = 0;
unsigned char* bytes = NULL;
unsigned char* sign_buf = NULL;
unsigned char hash[32];
// build the struct
struct Libp2pRecord record;
record.key = (char*)key;
record.key_size = strlen(key);
record.value = (char*)value;
record.value_size = vlen;
// clear the rest of the fields
record.signature = NULL;
record.signature_size = 0;
//TODO: what should we put in the time field?
record.time_received = NULL;
record.time_received_size = 0;
// build a hash of the author's public key
libp2p_crypto_hashing_sha256(sk->public_key_der, sk->public_key_length, &hash[0]);
record.author = &hash[0];
record.author_size = 32;
bytes_size = record.key_size + record.value_size + record.author_size;
bytes = malloc(bytes_size);
if (bytes == NULL)
goto exit;
// build the signature
if (sign) {
memcpy(&bytes[0], record.key, record.key_size);
memcpy(&bytes[record.key_size], record.value, record.value_size);
memcpy(&bytes[record.key_size + record.value_size], record.author, record.author_size);
size_t sign_length = 0;
if (!libp2p_crypto_rsa_sign ((struct RsaPrivateKey*)sk, bytes, bytes_size, &sign_buf, &sign_length))
goto exit;
record.signature = bytes;
record.signature_size = bytes_size;
}
// now protobuf the struct
size_t protobuf_size = libp2p_record_protobuf_encode_size(&record);
*record_buf = malloc(protobuf_size);
if (*record_buf == NULL)
goto exit;
if (!libp2p_record_protobuf_encode(&record, *record_buf, protobuf_size, &protobuf_size))
goto exit;
// we're done here. Cleanup time.
retVal = 0;
exit:
if (bytes != NULL)
free(bytes);
if (sign_buf != NULL)
free(sign_buf);
if (retVal == 0) {
free(*record_buf);
*record_buf = NULL;
}
return retVal;
}