有缘人拿去。。。RFC 3394,AESUnwrap。。。某些情况下使用的。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 | uint8_t AES_unwrap(uint8_t *kek, uint16_t key_len, uint8_t *cipher_text, uint16_t cipher_len, uint8_t *output){ uint8_t a[8], b[16]; uint8_t *r; uint8_t *c; uint16_t i, j, n; AES_KEY ctx; if (! kek || cipher_len < 16 || ! cipher_text || ! output) { /* We don't do anything with the return value */ return 1; } /* Initialize variables */ n = (cipher_len/8)-1; /* the algorithm works on 64-bits at a time */ memcpy(a, cipher_text, 8); r = output; c = cipher_text; memcpy(r, c+8, cipher_len - 8); /* Compute intermediate values */ for (j=5; j >= 0; --j) { r = output + (n - 1) * 8; /* DEBUG_DUMP("r1", (r-8), 8); */ /* DEBUG_DUMP("r2", r, 8); */ for (i = n; i >= 1; --i) { uint16_t t = (n*j) + i; /* DEBUG_DUMP("a", a, 8); */ memcpy(b, a, 8); b[7] ^= t; /* DEBUG_DUMP("a plus t", b, 8); */ memcpy(b+8, r, 8); AES_set_decrypt_key(kek, 128, &ctx); AES_decrypt(b, b, &ctx); /* NOTE: we are using the same src and dst buffer. It's ok. */ /* DEBUG_DUMP("aes decrypt", b, 16) */ memcpy(a,b,8); memcpy(r, b+8, 8); r -= 8; } } /* DEBUG_DUMP("a", a, 8); */ /* DEBUG_DUMP("output", output, cipher_len - 8); */ return 0;} |