c-libp2p/crypto/key.c

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#include <stdio.h>
/**
* Utilities for public keys
*/
enum KeyType { KEYTYPE_RSA, KEYTYPE_ED25519, KEYTYPE_INVALID };
struct PublicKey {
enum KeyType key_type;
char* raw_key;
size_t raw_key_size;
};
struct PublicKey* libp2p_crypto_public_key_new() {
struct PublicKey* retVal = malloc(sizeof(struct PublicKey));
if (retVal == NULL)
return NULL;
retVal->key_type = KEYTYPE_INVALID;
retVal->raw_key = NULL;
retVal->raw_key_size = 0;
return retVal;
}
void libp2p_crypto_public_key_free(struct PublicKey* in) {
if (in != NULL) {
if (in->raw_key != NULL)
free(in->raw_key);
free(in);
in = NULL;
}
}
/**
* Unmarshal a public key from a protobuf
*/
int libp2p_crypto_public_key_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct PublicKey** out) {
// first field is type (RSA vs ED25519)
// second field is the public key
size_t pos = 0;
int retVal = 0;
if ( (*out = libp2p_crypto_public_key_new()) == NULL)
goto exit;
while(pos < buffer_length) {
size_t bytes_read = 0;
int field_no;
enum WireType field_type;
if (protobuf_decode_field_and_type(&buffer[pos], buffer_length, &field_no, &field_type, &bytes_read) == 0) {
goto exit;
}
pos += bytes_read;
switch(field_no) {
case (1): // type
if (protobuf_decode_varint(&buffer[pos], buffer_length - pos, &((*out)->key_type), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
case (2): // key
if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&((*out)->raw_key), &((*out)->raw_key_size), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
}
}
retVal = 1;
exit:
if (retVal == 0) {
libp2p_crypto_public_key_free(*out);
}
return retVal;
}