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created why2_chat_ecc_encrypt fn

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This commit is contained in:
Václav Šmejkal 2025-02-01 14:54:11 +01:00
parent bf583fd495
commit e51a6bf4e8
Signed by: ENGO150
GPG Key ID: 4A57E86482968843
2 changed files with 49 additions and 3 deletions
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2
include/chat/crypto.h
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@ -49,6 +49,8 @@ why2_bool why2_chat_ecc_verify_signature(char *message, char *signature, EVP_PKE
char *why2_chat_ecc_serialize_public_key(); //GET PUBLIC ECC KEY IN BASE64
EVP_PKEY* why2_chat_ecc_deserialize_public_key(char *pubkey); //GET EVP_PKEY FROM BASE64 PUBLIC ECC KEY
char *why2_chat_ecc_encrypt(char *message, char *key); //ENCRYPT message WITH ECC key
char *why2_sha256(char *input, size_t length); //HASH input USING SHA256 AND RETURN IN STRING
#ifdef __cplusplus

50
src/chat/crypto.c
View File

@ -24,14 +24,15 @@ along with this program. If not, see <https://www.gnu.org/licenses/>.
#include <unistd.h>
#include <sys/stat.h>
#include <why2/memory.h>
#include <why2/misc.h>
#include <openssl/sha.h>
#include <openssl/evp.h>
#include <openssl/pem.h>
#include <openssl/ec.h>
#include <why2/encrypter.h>
#include <why2/memory.h>
#include <why2/misc.h>
EVP_PKEY *keypair = NULL; //KEYPAIR
//LOCAL
@ -258,6 +259,49 @@ EVP_PKEY* why2_chat_ecc_deserialize_public_key(char *pubkey)
return key;
}
char *why2_chat_ecc_encrypt(char *message, char *key)
{
//VARIABLES
size_t key_length;
char *secret = NULL;
size_t secret_len;
char *recipient_pubkey_decoded = base64_decode(key, &key_length); //DECODE key
why2_output_flags encrypted;
char *encrypted_text;
char *returning;
char *sym_key;
BIO *bio = BIO_new_mem_buf(recipient_pubkey_decoded, -1);
EVP_PKEY *recipient_pubkey = PEM_read_bio_PUBKEY(bio, NULL, NULL, NULL);
//CALCULATE SHARED SECRET
calculate_ecdh_secret(keypair, recipient_pubkey, &secret, &secret_len);
//DERIVE WHY2 KEY (SHA256)
sym_key = why2_sha256(secret, secret_len);
//ENCRYPTION SETTINGS
if (why2_get_key_length() < strlen(sym_key)) why2_set_key_length(strlen(sym_key)); //ALLOW sym_key'S LENGTH
why2_set_flags((why2_input_flags) { 0, 0, 0, WHY2_v4, WHY2_OUTPUT_TEXT, WHY2_CHAT_PADDING(strlen(sym_key)) });
//ENCRYPT MESSAGE
encrypted = why2_encrypt_text(message, sym_key);
encrypted_text = why2_strdup(encrypted.output_text);
//CONVERT TO BASE64
returning = base64_encode(encrypted_text, strlen(encrypted_text));
//DEALLOCATION
BIO_free(bio);
EVP_PKEY_free(recipient_pubkey);
why2_deallocate(secret);
why2_deallocate(sym_key);
why2_deallocate(recipient_pubkey_decoded);
why2_deallocate(encrypted_text);
why2_deallocate_output(encrypted);
return returning;
}
void why2_chat_deallocate_keys(void)
{
//DEALLOCATE THE pkey