Próbuję zaszyfrować ciąg „HELLO” za pomocą szyfrowania RSA przy użyciu PKCS1 Padding. Używam openssl do generowania pary kluczy i wykonywania szyfrowania.

Problem: Otrzymuję wygenerowany encypted tekst o zmiennej długości.

Private Key: LS0tLS1CRUdJTiBSU0EgUFJJVkFURSBLRVktLS0tLQpNSUlFb3dJQkFBS0NBUUVBbzdOdmUwZlg3L2NjVExibWhQOWNYUVI5WWFrMi9Oa3Q2bVkwNkpjNEJjWmswemdiCnZ4ek5mTC9sNVQzd1pQcDBWa204RGozcjNVUStMMXlyRjF6bGpBSXE5MlJQcnVWRFpacTJOcXJFelhyTUZxcUMKaWhEMU04dW1EVTNNUTNCMnYxdzdsVU1uWE1Ec21LMDVxbWJRQnRzckp1ck93Mm95a2VrT0dRdndEQWRjZmIydQpVcW5NNVc2OUp3eXNQaTVkc3VhOFBXM0FIK3o0b1lRZXhrOFh4KzRWSllTNkxvVGpaeGFPNysvNXRHMVJhUUc1CklHbFQrZUFjTmtXK1pTKzlzWldXdWRGVldNeGVQaE9jSVdmL1lsNW9HSm5LaUVKRU12bkdzRmpKRlpicTVCajgKaCtyb0xjdWZvWnNPYnVRM3draFpIakNKakFQRmlhcktIR3VjQXdJREFRQUJBb0lCQUVObGp0SnN3OFN5TWw2TApOdUV1MlhJYWRSeU9OR3RwWnZRSVhHUWVUaHhpa0FRK0ozNUpkM2lTOFMydWtKaWlYTjlod0NFRThXVEp3ZWh4CitLYkh3bUlnU2x4TVdsb2hYZHdwRkRmeG10RVdhNHd4YTBrNHJodEREdnlQT1RmU3g3RUZZaXFUMlZMZ3d3Z2cKMllzRWhVVXRXdGpNOTQrUTIzMGpQSUNuWDQ4emwvZnk2YStldzZFbmNpRzNpcEppczdPc3ZxVmc4OGluSDNPWgp3Z3R4ZmpHa2RIL0NzUGk3eVYzMHdmMTZWNThFcmtlamxtOHMrRGtvcTNpRXhBekMvL3Q2TnY0Vlh5VEJYNjRHClV3RjVHdDcyL0pLTldMdytpU1dKdWtkR21wcCtxQlBROHc3QU0xeHUyalc4SFZKbUhUZGRLazBSby9KbVNwNWgKelhic0w4RUNnWUVBMVFEcVFaU0x0SElsVU1ibC9SOWZLWWJVV3JhbE9wTDdjM0EwVnplUWlya2tEV1VnSE9MTgp5bk9NYlUxcitCUFRiN1FoMytsWWlod2tHVHZsaWR6cC9BVDdDSHlpYWVnZVh2RWY1YVFNVGlhajU2UCtkNFh4CmtnZ3ZOZmI5R0VEMkovdi82SS91cTlZb1N6aUY0R0M3R09rYWxtamNSNmJ2U2trdC9QRitjWk1DZ1lFQXhMN0cKMk8vQTVQaGoraHpGbFVhNDFLb1F6WTJ4dUkrTnNFZUZSbStsejJ4M00weHIrRlBGelhnQjFIOHBNcGNxMTlFMAp6VGNiODYvck40eFZmMkJwNnNCOUFaSG42NWM3cy9rZUllNTRnMVNsRlN2NEJ1SDgyVGZnUzAwKzUrZ0hMN0I0CmY0R2ZXVm1jQkp6Sng1Njl2Ynh5TUpnSUJkRlMranIySzhFVmNkRUNnWUJsZlF3Z3R5QmhsOG1EMVdFYjIrakIKcG9aanVvYTdnL0RmTGVVaWNVMGphOWRyc25VOGppd3pmQjY2clpyMkZxdzFtd1JRNWFQVUdsaHcxWU1tenVXRgp1UEhMTjJkRFF0L0ZxT25qeHVnK0RGY29OWkUzYmRDT0hld3dzRUFqWUVCcENMOEVGaUJJSzhBREp5bFNvWVJECitEMDgwVFd6eGl4Wm5zaVVycFBxbFFLQmdRQ21EdXZnNElPci91YkxqUXRMa25TZ3NxWWFDTFZ2TkdMLzNXM2sKNUlsTHlKM1hnM0pDRjlzRk1IeEM4YzFBOFF4dE9odlo5ZUMyenMyMmhkRUlBTVdGS1ZDWlNhQTVYZDA3YTFGKwpqRHZWaFZVTXlKN0FtRytFbTcvSmJ2cGdYSnZzS1lPYkF6b08vUzVOU2xTWkV5Zk5CRWhSTVpEYjhEQ2NHYlg3CmVpM3ljUUtCZ0dJcDF2VWpRYVFaM3hhUGJ3eGpKcHlkSWQ1bk0vTllDb2doMTl6Z0tIZlNVOGxRenFsWHB0ZEEKenloOEYyLzQ5cWNuVEVnZlh0bmJ4bTRKbTV5ck5xdHUyVDFpdWt5NStST2Vud1Y1VjFqRVZETDgrZ0VsOGt2cApvVUlNSFg3ZThWYW5FTGptSWo4WU1DcGtEOFQwOVFGajhzSU5DaVZNMjk3QUs4REwyWjhFCi0tLS0tRU5EIFJTQSBQUklWQVRFIEtFWS0tLS0tCg==

Public Key: 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

Encrypted Text for HELLO in Run1: XuKAosKxw6BWXcK/w7cgMBww4oCZxLHDgO+sggXigJQR4oC5w7o3SAFbTTHiiJrDsuKJoM6p4oC5YMOf4oCwC8ODYsOa76O/MQ5BAUF2w5xMw7vDrkzigJPDq30Bw4bCoRnDgWrLnHHDukNvdcOuKkLCtsOAw6rigJnDseKAucO6G1EcwqfFkzPDiyLDnAjigKHDmUbDoxHCu8O8WU9LwrXigKDDssOvw7zDrhNfw7gCw7bvo78Jw4hp4oiGc8OrxbhTwrfiiI9mw5xQGgg6wrco76yCw6V1fg7DlDbDknPLnWY7KuKAmuKAnU3DqsOcwqzEsRg7y5g7O3RmdMOcD8OZw4TiiaXDoU7LmcWSw6fDmeKAucWTGBDFkiTiiYjiiJ5JXA3DksOuw4ldd8uH76yCUQwm4oKsw7nDhe+sgR0RUA/iiJ4vH2gTO+KAoW7DlcK/w7o8y5tFZHrCsGfigJrDocKwy5zDjMK7w4pKCibDguKInnkbUuKImsuYy5rigKDCrsO/C1HDo3LCrMOqwrXigJzigJ7DqeKAmuKIj3LDjgnDscOlwrZbDzVZw5PDmXlYO8ORFA==

Encrypted Text for HELLO in Run2: E0dedDrigJxBw5jCqhwLRA4yHcOzwqgVa1HCrmkWKcua4omlD+KEoi85G1csw7k=


NOTE: All data above is Base64Encoded.

Używam poniższego kodu do wygenerowania KeyPair i wyodrębnienia prywatnych i publicznych kluczy:

RSA *rsaKeyPair = NULL;
EVP_PKEY *PrivateKey = NULL;
rsaKeyPair = RSA_new();

BIGNUM *e = NULL;
e = BN_new();
BN_set_word(e, 65537);

//Generating KeyPair
RSA_generate_key_ex(rsaKeyPair, 2048, e, NULL);

PrivateKey = EVP_PKEY_new();

BIO *pri = BIO_new(BIO_s_mem());
BIO *pub = BIO_new(BIO_s_mem());

PEM_write_bio_RSAPrivateKey(pri, rsaKeyPair, NULL, NULL, 0, NULL, NULL);
PEM_write_bio_RSAPublicKey(pub, rsaKeyPair);

size_t pri_len = BIO_pending(pri);
size_t pub_len = BIO_pending(pub);

char *pri_key = malloc(pri_len + 1);
char *pub_key = malloc(pub_len + 1);

BIO_read(pri, pri_key, pri_len);
BIO_read(pub, pub_key, pub_len);

pri_key[pri_len] = '\0';
pub_key[pub_len] = '\0';

NSString *priK = [[[NSString stringWithFormat:@"%s",pri_key] dataUsingEncoding:NSUTF8StringEncoding] base64EncodedString];
NSString *privateKey = [[priK componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]] componentsJoinedByString:@""];

NSString *PKK = [[[NSString stringWithFormat:@"%s",pub_key] componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]] componentsJoinedByString:@""];
NSString *pubK = [[PKK dataUsingEncoding:NSUTF8StringEncoding] base64EncodedString];
NSString *publicKey = [[pubK componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]] componentsJoinedByString:@""];


//IMP: publicKey is shared along with encrypted text(HELLO string encrypted with PrivateKey)

Szyfruję HELLO z PrivateKey, korzystając z poniższego:

NSString *myString = @"HELLO";
const char *msg = (const char *)[myString cStringUsingEncoding:NSASCIIStringEncoding];;
err = malloc(130);
if((encrypt_len = RSA_private_encrypt(strlen(msg), (unsigned char*)msg, (unsigned char*)encrypt, rsaKeyPair, RSA_PKCS1_PADDING)) == -1) {
    ERR_load_crypto_strings();
    ERR_error_string(ERR_get_error(), err);
    fprintf(stderr, "Error encrypting message: %s\n", err);
}
NSString *validatorBase64 = [[[NSString stringWithFormat:@"%s",encrypt] dataUsingEncoding:NSUTF8StringEncoding] base64EncodedString];
NSString *validator = [[validatorBase64 componentsSeparatedByCharactersInSet:[NSCharacterSet newlineCharacterSet]] componentsJoinedByString:@""];