diff --git a/wolfcrypt/src/aes.c b/wolfcrypt/src/aes.c index 61f8e9e311f..5f8d3ddf93b 100644 --- a/wolfcrypt/src/aes.c +++ b/wolfcrypt/src/aes.c @@ -15210,15 +15210,14 @@ int wc_AesCcmDecrypt(Aes* aes, byte* out, const byte* in, word32 inSz, o += WC_AES_BLOCK_SIZE; } - if ((ret == 0) && (inSz > 0)) + /* oSz, not inSz, is the count of bytes left after the block loop above -- + * inSz is kept pristine here for the CBC-MAC phase below. */ + if ((ret == 0) && (oSz > 0)) ret = AesEncrypt_preFetchOpt(aes, B, A, &did_prefetches); - if ((ret == 0) && (inSz > 0)) { + if ((ret == 0) && (oSz > 0)) { xorbuf(A, in, oSz); XMEMCPY(o, A, oSz); - for (i = 0; i < lenSz; i++) - B[WC_AES_BLOCK_SIZE - 1 - i] = 0; - ret = AesEncrypt_preFetchOpt(aes, B, A, &did_prefetches); } if (ret == 0) { diff --git a/wolfcrypt/test/test.c b/wolfcrypt/test/test.c index 5f7047ac792..9549dd1d4a6 100644 --- a/wolfcrypt/test/test.c +++ b/wolfcrypt/test/test.c @@ -21775,6 +21775,141 @@ static wc_test_ret_t aesccm_128_large_test(Aes* enc) return ret; } +/* Exercise message lengths that are exact multiples of the AES block size. + * These leave no partial block after the CTR loop, a case the other AES-CCM + * vectors here (23 and 73 bytes) never reach. Vectors generated with + * pyca/cryptography AESCCM. */ +static wc_test_ret_t aesccm_128_aligned_test(Aes* enc) +{ + wc_test_ret_t ret; + WOLFSSL_SMALL_STACK_STATIC const byte k[] = + { + 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, + 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf + }; + WOLFSSL_SMALL_STACK_STATIC const byte iv[] = + { + 0x00, 0x00, 0x00, 0x03, 0x02, 0x01, 0x00, 0xa0, + 0xa1, 0xa2, 0xa3, 0xa4, 0xa5 + }; + WOLFSSL_SMALL_STACK_STATIC const byte a[] = + { + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 + }; + /* plaintext - one block */ + WOLFSSL_SMALL_STACK_STATIC const byte p1[] = + { + 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 + }; + /* ciphertext - one block */ + WOLFSSL_SMALL_STACK_STATIC const byte c1[] = + { + 0x58, 0x8c, 0x97, 0x9a, 0x61, 0xc6, 0x63, 0xd2, + 0xf0, 0x66, 0xd0, 0xc2, 0xc0, 0xf9, 0x89, 0x80 + }; + /* tag - authentication - one block */ + WOLFSSL_SMALL_STACK_STATIC const byte t1[] = + { + 0x6e, 0xcb, 0xa5, 0x36, 0xf1, 0x67, 0x5d, 0x6f + }; + /* plaintext - four blocks */ + WOLFSSL_SMALL_STACK_STATIC const byte p4[] = + { + 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, + 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, + 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 + }; + /* ciphertext - four blocks */ + WOLFSSL_SMALL_STACK_STATIC const byte c4[] = + { + 0x58, 0x8c, 0x97, 0x9a, 0x61, 0xc6, 0x63, 0xd2, + 0xf0, 0x66, 0xd0, 0xc2, 0xc0, 0xf9, 0x89, 0x80, + 0x6d, 0x5f, 0x6b, 0x61, 0xda, 0xc3, 0x84, 0xe0, + 0x44, 0x2d, 0xbe, 0x25, 0xfa, 0x48, 0x2b, 0xa8, + 0x36, 0x0b, 0xbf, 0x01, 0xc0, 0x12, 0x45, 0xa4, + 0x82, 0x9f, 0x20, 0x6c, 0xc3, 0xd6, 0xae, 0x5b, + 0x54, 0x8d, 0xd0, 0xb1, 0x69, 0x2c, 0xec, 0x5e, + 0x95, 0xa5, 0x6b, 0x48, 0xc3, 0xc6, 0xc8, 0x9e + }; + /* tag - authentication - four blocks */ + WOLFSSL_SMALL_STACK_STATIC const byte t4[] = + { + 0x22, 0xb4, 0x3d, 0x0e, 0x5b, 0x2f, 0x01, 0xdc + }; +#ifdef HAVE_AES_DECRYPT + byte p2[sizeof(p4)]; +#endif + byte c2[sizeof(c4)]; + byte t2[sizeof(t4)]; + + ret = wc_AesCcmSetKey(enc, k, sizeof(k)); + if (ret != 0) + ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out); + + /* one block - the CTR loop runs once and consumes the whole message */ + XMEMSET(c2, 0, sizeof(c2)); + XMEMSET(t2, 0, sizeof(t2)); + ret = wc_AesCcmEncrypt(enc, c2, p1, sizeof(p1), iv, sizeof(iv), + t2, sizeof(t2), a, sizeof(a)); + if (ret != 0) + ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out); + if (XMEMCMP(c1, c2, sizeof(c1))) + ERROR_OUT(WC_TEST_RET_ENC_NC, out); + if (XMEMCMP(t1, t2, sizeof(t1))) + ERROR_OUT(WC_TEST_RET_ENC_NC, out); + +#ifdef HAVE_AES_DECRYPT + XMEMSET(p2, 0, sizeof(p2)); + ret = wc_AesCcmDecrypt(enc, p2, c1, sizeof(c1), iv, sizeof(iv), + t1, sizeof(t1), a, sizeof(a)); + if (ret != 0) + ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out); + if (XMEMCMP(p1, p2, sizeof(p1))) + ERROR_OUT(WC_TEST_RET_ENC_NC, out); +#endif + + /* four blocks - also covers the AES-NI four-block path consuming the + * whole message */ + XMEMSET(c2, 0, sizeof(c2)); + XMEMSET(t2, 0, sizeof(t2)); + ret = wc_AesCcmEncrypt(enc, c2, p4, sizeof(p4), iv, sizeof(iv), + t2, sizeof(t2), a, sizeof(a)); + if (ret != 0) + ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out); + if (XMEMCMP(c4, c2, sizeof(c4))) + ERROR_OUT(WC_TEST_RET_ENC_NC, out); + if (XMEMCMP(t4, t2, sizeof(t4))) + ERROR_OUT(WC_TEST_RET_ENC_NC, out); + +#ifdef HAVE_AES_DECRYPT + XMEMSET(p2, 0, sizeof(p2)); + ret = wc_AesCcmDecrypt(enc, p2, c4, sizeof(c4), iv, sizeof(iv), + t4, sizeof(t4), a, sizeof(a)); + if (ret != 0) + ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out); + if (XMEMCMP(p4, p2, sizeof(p4))) + ERROR_OUT(WC_TEST_RET_ENC_NC, out); + + /* a corrupted tag must still be rejected on a block-aligned message */ + XMEMCPY(t2, t4, sizeof(t4)); + t2[0] ^= 0x01; + ret = wc_AesCcmDecrypt(enc, p2, c4, sizeof(c4), iv, sizeof(iv), + t2, sizeof(t2), a, sizeof(a)); + if (ret != WC_NO_ERR_TRACE(AES_CCM_AUTH_E)) + ERROR_OUT(WC_TEST_RET_ENC_NC, out); +#endif + + ret = 0; + out: + return ret; +} + static wc_test_ret_t aesccm_128_badarg_test(Aes* enc) { wc_test_ret_t ret; @@ -21990,6 +22125,10 @@ static wc_test_ret_t aesccm_128_test(Aes* enc) if (ret != 0) return ret; + ret = aesccm_128_aligned_test(enc); + if (ret != 0) + return ret; + ret = aesccm_128_badarg_test(enc); if (ret != 0) return ret;