m26610 now also checking second block of plaintext, moved AES_GCM_decrypt to seperate function

This commit is contained in:
Your Name 2023-03-08 00:50:40 +01:00
parent b035c6e408
commit 70885319f3
3 changed files with 19 additions and 19 deletions

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@ -303,3 +303,9 @@ DECLSPEC void AES_GCM_GHASH_GLOBAL (PRIVATE_AS const u32 *subkey, PRIVATE_AS con
AES_GCM_ghash (subkey, len_buf, 16, out);
}
void AES_GCM_decrypt (PRIVATE_AS u32 *key, PRIVATE_AS u32 *J0, PRIVATE_AS const u32 *in, int in_len, PRIVATE_AS u32 *out, SHM_TYPE u32 *s_te0, SHM_TYPE u32 *s_te1, SHM_TYPE u32 *s_te2, SHM_TYPE u32 *s_te3, SHM_TYPE u32 *s_te4)
{
AES_GCM_inc32(J0); // the first ctr is used to compute the tag, only the second is used for decryption: https://en.wikipedia.org/wiki/Galois/Counter_Mode#/media/File:GCM-Galois_Counter_Mode_with_IV.svg
AES_GCM_GCTR (key, J0, in, in_len, out, s_te0, s_te1, s_te2, s_te3, s_te4); // decrypt the first block of ciphertext
}

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@ -17,5 +17,6 @@ DECLSPEC void AES_GCM_gctr (PRIVATE_AS const u32 *key, PRIVATE_AS const u32 *iv,
DECLSPEC void AES_GCM_GCTR (PRIVATE_AS u32 *key, PRIVATE_AS u32 *J0, PRIVATE_AS const u32 *in, int in_len, PRIVATE_AS u32 *out, SHM_TYPE u32 *s_te0, SHM_TYPE u32 *s_te1, SHM_TYPE u32 *s_te2, SHM_TYPE u32 *s_te3, SHM_TYPE u32 *s_te4);
DECLSPEC void AES_GCM_GHASH (PRIVATE_AS const u32 *subkey, PRIVATE_AS const u32 *aad_buf, int aad_len, PRIVATE_AS const u32 *enc_buf, int enc_len, PRIVATE_AS u32 *out);
DECLSPEC void AES_GCM_GHASH_GLOBAL (PRIVATE_AS const u32 *subkey, PRIVATE_AS const u32 *aad_buf, int aad_len, GLOBAL_AS const u32 *enc_buf, int enc_len, PRIVATE_AS u32 *out);
DECLSPEC void AES_GCM_decrypt (PRIVATE_AS u32 *key, PRIVATE_AS u32 *J0, PRIVATE_AS const u32 *in, int in_len, PRIVATE_AS u32 *out, SHM_TYPE u32 *s_te0, SHM_TYPE u32 *s_te1, SHM_TYPE u32 *s_te2, SHM_TYPE u32 *s_te3, SHM_TYPE u32 *s_te4);
#endif // INC_CIPHER_AES_GCM_H

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@ -348,17 +348,12 @@ KERNEL_FQ void m26610_comp (KERN_ATTR_TMPS_ESALT (pbkdf2_sha256_tmp_t, pbkdf2_sh
AES_GCM_Prepare_J0 (iv, iv_len, subKey, J0);
//first block of ciphertext
u32 ct[4] = {
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[0],
u32 ct[8] = {
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[0], //first block of ciphertext
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[1],
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[2],
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[3]
};
// second block of ciphertext
u32 ct2[4] = {
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[4],
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[3],
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[4], // second block of ciphertext
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[5],
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[6],
esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[7]
@ -366,19 +361,17 @@ KERNEL_FQ void m26610_comp (KERN_ATTR_TMPS_ESALT (pbkdf2_sha256_tmp_t, pbkdf2_sh
//if ((gid == 0) && (lid == 0)) printf("esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[3]=0x%08x\n", esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[3]);
//if ((gid == 0) && (lid == 0)) printf("esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[4]=0x%08x\n", esalt_bufs[DIGESTS_OFFSET_HOST].ct_buf[4]);
u32 pt[4] = { 0 };
u32 pt2[4] = { 0 };
u32 pt[8] = { 0 };
AES_GCM_decrypt (key, J0, ct, 32, pt, s_te0, s_te1, s_te2, s_te3, s_te4);
// we try to decrypt the ciphertext
// TODO this can be moved to a separate decryption function in inc_cipher_aes-gcm.cl
AES_GCM_inc32(J0); // the first ctr is used to compute the tag, only the second is used for decryption: https://en.wikipedia.org/wiki/Galois/Counter_Mode#/media/File:GCM-Galois_Counter_Mode_with_IV.svg
AES_GCM_GCTR (key, J0, ct, 16, pt, s_te0, s_te1, s_te2, s_te3, s_te4); // decrypt the first block of ciphertext
AES_GCM_inc32(J0);
AES_GCM_GCTR (key, J0, ct2, 16, pt2, s_te0, s_te1, s_te2, s_te3, s_te4); // decrypt the second block of ciphertext
// TODO check entropy, but not sure what MAX_ENTROPY should be..
//const float entropy = hc_get_entropy (pt, 8);
//printf("entropy=%f\n", entropy);
//if ((gid == 0) && (lid == 0)) printf ("pt[0]=%08x\n", pt[0]); // should be 5b7b2274 or [{"type"
if ((gid == 0) && (lid == 0)) printf ("pt2[0]=%08x%08x\n", pt2[0], pt2[1]); // should be 2054726565222c22 or Tree","
//if ((gid == 0) && (lid == 0)) printf ("pt[0]=%08x%08x\n", pt[4], pt[5]); // should be 2054726565222c22 or Tree","
// cast plaintext buffer to byte such that we can do a byte per byte comparison
PRIVATE_AS const u32 *u32OutBufPtr = (PRIVATE_AS u32 *) pt;
@ -389,7 +382,7 @@ KERNEL_FQ void m26610_comp (KERN_ATTR_TMPS_ESALT (pbkdf2_sha256_tmp_t, pbkdf2_sh
// if not, decryption was not successful
bool correct = true;
for(int i=0;i<16;i++)
for(int i=0;i<32;i++)
{
if(u8OutBufPtr[i] >=0x20 && u8OutBufPtr[i] <= 0x7e) {
//if ((gid == 0) && (lid == 0)) printf("correct ASCII byte[%d]=0x%02x\n", i, u8OutBufPtr[i]);