C++ (Cpp) ccrsa_oaep_encode примеры использования

Пример #1

Файл: ccrsa_sign_oaep.c Проект: randombit/hacrypto

/* siglen will be the actual lenght of the prime in bytes */
int ccrsa_sign_oaep(ccrsa_full_ctx_t key,
                    const struct ccdigest_info* di, struct ccrng_state *rng,
                    size_t digest_len, const uint8_t *digest,
                    size_t *sig_len, uint8_t *sig)
{
    size_t m_size = ccn_write_uint_size(ccrsa_ctx_n(key), ccrsa_ctx_m(key));
    cc_size n=ccrsa_ctx_n(key);
    cc_unit s[n];
    int err;

    if(*sig_len<m_size)
        return CCRSA_INVALID_INPUT;

    *sig_len=m_size;

    err=ccrsa_oaep_encode(di, rng, m_size, s, digest_len, digest);
    if(err) return err;

    err=ccrsa_priv_crypt(ccrsa_ctx_private(key), s, s);
    if(err) return err;

    /* we need to write leading zeroes if necessary */
    ccn_write_uint_padded(n, s, m_size, sig);

    return 0;
}

Пример #2

Файл: SecRSAKey.c Проект: Apple-FOSS-Mirror/Security

static OSStatus SecRSAPublicKeyRawEncrypt(SecKeyRef key, SecPadding padding,
    const uint8_t *plainText, size_t plainTextLen,
	uint8_t *cipherText, size_t *cipherTextLen) {
    OSStatus result = errSecParam;
    ccrsa_pub_ctx_t pubkey;
    pubkey.pub = key->key;

    cc_unit s[ccrsa_ctx_n(pubkey)];
    const size_t m_size = ccn_write_uint_size(ccrsa_ctx_n(pubkey), ccrsa_ctx_m(pubkey));

    require(cipherTextLen, errOut);
    require(*cipherTextLen >= m_size, errOut);

    uint8_t* sBytes = (uint8_t*) s;

    switch (padding) {
        case kSecPaddingNone:
            require_noerr_quiet(ccn_read_uint(ccrsa_ctx_n(pubkey), s, plainTextLen, plainText), errOut);
            require_quiet(ccn_cmp(ccrsa_ctx_n(pubkey), s, ccrsa_ctx_m(pubkey)) < 0, errOut);
            break;

        case kSecPaddingPKCS1:
        {
            // Create PKCS1 padding:
            //
            // 0x00, 0x01 (RSA_PKCS1_PAD_ENCRYPT), 0xFF .. 0x00, signedData
            //
            const int kMinimumPadding = 1 + 1 + 8 + 1;

            require_quiet(plainTextLen < m_size - kMinimumPadding, errOut);

            size_t prefix_zeros = ccn_sizeof_n(ccrsa_ctx_n(pubkey)) - m_size;
            
            while (prefix_zeros--)
                 *sBytes++ = 0x00;

           size_t pad_size = m_size - plainTextLen;

            *sBytes++ = 0x00;
            *sBytes++ = RSA_PKCS1_PAD_ENCRYPT;

            ccrng_generate(ccrng_seckey, pad_size - 3, sBytes);
            // Remove zeroes from the random pad

            const uint8_t* sEndOfPad = sBytes + (pad_size - 3);
            while (sBytes < sEndOfPad)
            {
                if (*sBytes == 0x00)
                    *sBytes = 0xFF; // Michael said 0xFF was good enough.

                ++sBytes;
            }

            *sBytes++ = 0x00;

            memcpy(sBytes, plainText, plainTextLen);

            ccn_swap(ccrsa_ctx_n(pubkey), s);
            break;
        }
        case kSecPaddingOAEP:
        {
            const struct ccdigest_info* di = ccsha1_di();

            const size_t encodingOverhead = 2 + 2 * di->output_size;

            require_action(m_size > encodingOverhead, errOut, result = errSecParam);
            require_action_quiet(plainTextLen < m_size - encodingOverhead, errOut, result = errSSLCrypto);

            require_noerr_action(ccrsa_oaep_encode(di,
                                                   ccrng_seckey,
                                                   m_size, s,
                                                   plainTextLen, plainText), errOut, result = errSecInternal);
           break;
        }
        default:
            goto errOut;
    }


    ccrsa_pub_crypt(pubkey, s, s);

    ccn_write_uint_padded(ccrsa_ctx_n(pubkey), s, m_size, cipherText);
    *cipherTextLen = m_size;

    result = errSecSuccess;

errOut:
    ccn_zero(ccrsa_ctx_n(pubkey), s);
    return result;
}