On Fri, May 20, 2016 at 10:03:27 -0400, John Ferlan wrote:
On 05/20/2016 08:56 AM, Peter Krempa wrote:
On Thu, May 19, 2016 at 16:29:01 -0400, John Ferlan wrote:
Introduce virCryptoHaveCipher and virCryptoEncryptData to handle performing encryption.
virCryptoHaveCipher: Boolean function to determine whether the requested cipher algorithm is available. It's expected this API will be called prior to virCryptoEncryptdata. It will return true/false.
virCryptoEncryptData: Based on the requested cipher type, call the specific encryption API to encrypt the data.
Currently the only algorithm support is the AES 256 CBC encryption.
Adjust tests for the API's
Signed-off-by: John Ferlan <jferlan@redhat.com> --- configure.ac | 1 + src/libvirt_private.syms | 2 + src/util/vircrypto.c | 192 ++++++++++++++++++++++++++++++++++++++++++++++- src/util/vircrypto.h | 20 ++++- tests/vircryptotest.c | 100 +++++++++++++++++++++++- 5 files changed, 312 insertions(+), 3 deletions(-)
[...]
+ /* Fill in the padding of the buffer with the size of the padding + * which is required for decryption. */ + for (i = datalen; i < ciphertextlen; i++) + ciphertext[i] = ciphertextlen - datalen; + + /* Initialize the gnutls cipher */ + enc_key.size = enckeylen; + enc_key.data = enckey; + if (iv) { + iv_buf.size = ivlen; + iv_buf.data = iv; + } + if ((rc = gnutls_cipher_init(&handle, gnutls_enc_alg, + &enc_key, &iv_buf)) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("failed to initialize cipher: '%s'"), + gnutls_strerror(rc)); + goto error; + } + + /* Encrypt the data and free the memory for cipher operations */ + rc = gnutls_cipher_encrypt(handle, ciphertext, ciphertextlen); + gnutls_cipher_deinit(handle);
memset(&enc_key, 0, sizeof(gnutls_datum_t)); memset(&iv_key, 0, sizeof(gnutls_datum_t));
Note that this doesn't catch the cleanup path if gnutls_cipher_init fails.
+ if (rc < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("failed to encrypt the data: '%s'"), + gnutls_strerror(rc)); + goto error; + } + + *ciphertextret = ciphertext; + *ciphertextlenret = ciphertextlen; + return 0; + + error: + VIR_DISPOSE_N(ciphertext, ciphertextlen); + return -1;
In both cases you should clear the stack'd copy of the encryption key.
+} +#endif +