5e4236d22
Denys Vlasenko
2018-11-23
Subject
tls: in AES-CBC code, do not set key for every record - do it once
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networking/tls.c +9 -3networking/tls_aes.c +17 -15networking/tls_aes.h +2 -2networking/tls_aesgcm.c +0 -10networking/tls_aesgcm.h +0 -2
networking/tls.c+9 -3
| @@ -758,7 +758,7 @@ static void xwrite_encrypted_and_hmac_signed(tls_state_t *tls, unsigned size, un | |
| /* Encrypt content+MAC+padding in place */ | |
| //optimize key setup | |
| aes_cbc_encrypt( | |
| - | tls->client_write_key, tls->key_size, /* selects 128/256 */ |
| + | &tls->aes_decrypt, /* selects 128/256 */ |
| buf - AES_BLOCK_SIZE, /* IV */ | |
| buf, size, /* plaintext */ | |
| buf /* ciphertext */ | |
| @@ -1061,7 +1061,7 @@ static int tls_xread_record(tls_state_t *tls, const char *expected) | |
| /* Decrypt content+MAC+padding, moving it over IV in the process */ | |
| sz -= AES_BLOCK_SIZE; /* we will overwrite IV now */ | |
| aes_cbc_decrypt( | |
| - | tls->server_write_key, tls->key_size, /* selects 128/256 */ |
| + | &tls->aes_decrypt, /* selects 128/256 */ |
| p, /* IV */ | |
| p + AES_BLOCK_SIZE, sz, /* ciphertext */ | |
| p /* plaintext */ | |
| @@ -1934,8 +1934,14 @@ static void send_client_key_exchange(tls_state_t *tls) | |
| dump_hex("client_write_IV:%s\n", | |
| tls->client_write_IV, tls->IV_size | |
| ); | |
| - | aesgcm_setkey(tls->H, &tls->aes_encrypt, tls->client_write_key, tls->key_size); |
| + | |
| aes_setkey(&tls->aes_decrypt, tls->server_write_key, tls->key_size); | |
| + | aes_setkey(&tls->aes_encrypt, tls->client_write_key, tls->key_size); |
| + | { |
| + | uint8_t iv[AES_BLOCK_SIZE]; |
| + | memset(iv, 0, AES_BLOCK_SIZE); |
| + | aes_encrypt_one_block(&tls->aes_encrypt, iv, tls->H); |
| + | } |
| } | |
| } | |
networking/tls_aes.c+17 -15
| @@ -326,8 +326,11 @@ static void InvMixColumns(unsigned astate[16]) | |
| } | |
| } | |
| - | static void aes_encrypt_1(unsigned astate[16], unsigned rounds, const uint32_t *RoundKey) |
| + | static void aes_encrypt_1(struct tls_aes *aes, unsigned astate[16]) |
| { | |
| + | unsigned rounds = aes->rounds; |
| + | const uint32_t *RoundKey = aes->key; |
| + | |
| for (;;) { | |
| AddRoundKey(astate, RoundKey); | |
| RoundKey += 4; | |
| @@ -355,22 +358,19 @@ void FAST_FUNC aes_encrypt_one_block(struct tls_aes *aes, const void *data, void | |
| for (i = 0; i < 16; i++) | |
| astate[i] = pt[i]; | |
| - | aes_encrypt_1(astate, aes->rounds, aes->key); |
| + | aes_encrypt_1(aes, astate); |
| for (i = 0; i < 16; i++) | |
| ct[i] = astate[i]; | |
| } | |
| - | void FAST_FUNC aes_cbc_encrypt(const void *key, int klen, void *iv, const void *data, size_t len, void *dst) |
| + | void FAST_FUNC aes_cbc_encrypt(struct tls_aes *aes, void *iv, const void *data, size_t len, void *dst) |
| { | |
| - | uint32_t RoundKey[60]; |
| uint8_t iv2[16]; | |
| - | unsigned rounds; |
| const uint8_t *pt = data; | |
| uint8_t *ct = dst; | |
| memcpy(iv2, iv, 16); | |
| - | rounds = KeyExpansion(RoundKey, key, klen); |
| while (len > 0) { | |
| { | |
| /* almost aes_encrypt_one_block(rounds, RoundKey, pt, ct); | |
| @@ -381,7 +381,7 @@ void FAST_FUNC aes_cbc_encrypt(const void *key, int klen, void *iv, const void * | |
| unsigned astate[16]; | |
| for (i = 0; i < 16; i++) | |
| astate[i] = pt[i] ^ iv2[i]; | |
| - | aes_encrypt_1(astate, rounds, RoundKey); |
| + | aes_encrypt_1(aes, astate); |
| for (i = 0; i < 16; i++) | |
| iv2[i] = ct[i] = astate[i]; | |
| } | |
| @@ -391,8 +391,11 @@ void FAST_FUNC aes_cbc_encrypt(const void *key, int klen, void *iv, const void * | |
| } | |
| } | |
| - | static void aes_decrypt_1(unsigned astate[16], unsigned rounds, const uint32_t *RoundKey) |
| + | static void aes_decrypt_1(struct tls_aes *aes, unsigned astate[16]) |
| { | |
| + | unsigned rounds = aes->rounds; |
| + | const uint32_t *RoundKey = aes->key; |
| + | |
| RoundKey += rounds * 4; | |
| AddRoundKey(astate, RoundKey); | |
| for (;;) { | |
| @@ -407,8 +410,10 @@ static void aes_decrypt_1(unsigned astate[16], unsigned rounds, const uint32_t * | |
| } | |
| #if 0 //UNUSED | |
| - | static void aes_decrypt_one_block(unsigned rounds, const uint32_t *RoundKey, const void *data, void *dst) |
| + | static void aes_decrypt_one_block(struct tls_aes *aes, const void *data, void *dst) |
| { | |
| + | unsigned rounds = aes->rounds; |
| + | const uint32_t *RoundKey = aes->key; |
| unsigned astate[16]; | |
| unsigned i; | |
| @@ -417,25 +422,22 @@ static void aes_decrypt_one_block(unsigned rounds, const uint32_t *RoundKey, con | |
| for (i = 0; i < 16; i++) | |
| astate[i] = ct[i]; | |
| - | aes_decrypt_1(astate, rounds, RoundKey); |
| + | aes_decrypt_1(aes, astate); |
| for (i = 0; i < 16; i++) | |
| pt[i] = astate[i]; | |
| } | |
| #endif | |
| - | void FAST_FUNC aes_cbc_decrypt(const void *key, int klen, void *iv, const void *data, size_t len, void *dst) |
| + | void FAST_FUNC aes_cbc_decrypt(struct tls_aes *aes, void *iv, const void *data, size_t len, void *dst) |
| { | |
| - | uint32_t RoundKey[60]; |
| uint8_t iv2[16]; | |
| uint8_t iv3[16]; | |
| - | unsigned rounds; |
| uint8_t *ivbuf; | |
| uint8_t *ivnext; | |
| const uint8_t *ct = data; | |
| uint8_t *pt = dst; | |
| - | rounds = KeyExpansion(RoundKey, key, klen); |
| ivbuf = memcpy(iv2, iv, 16); | |
| while (len) { | |
| ivnext = (ivbuf==iv2) ? iv3 : iv2; | |
| @@ -447,7 +449,7 @@ void FAST_FUNC aes_cbc_decrypt(const void *key, int klen, void *iv, const void * | |
| unsigned astate[16]; | |
| for (i = 0; i < 16; i++) | |
| ivnext[i] = astate[i] = ct[i]; | |
| - | aes_decrypt_1(astate, rounds, RoundKey); |
| + | aes_decrypt_1(aes, astate); |
| for (i = 0; i < 16; i++) | |
| pt[i] = astate[i] ^ ivbuf[i]; | |
| } | |
networking/tls_aes.h+2 -2
| @@ -10,5 +10,5 @@ void aes_setkey(struct tls_aes *aes, const void *key, unsigned key_len) FAST_FUN | |
| void aes_encrypt_one_block(struct tls_aes *aes, const void *data, void *dst) FAST_FUNC; | |
| - | void aes_cbc_encrypt(const void *key, int klen, void *iv, const void *data, size_t len, void *dst) FAST_FUNC; |
| - | void aes_cbc_decrypt(const void *key, int klen, void *iv, const void *data, size_t len, void *dst) FAST_FUNC; |
| + | void aes_cbc_encrypt(struct tls_aes *aes, void *iv, const void *data, size_t len, void *dst) FAST_FUNC; |
| + | void aes_cbc_decrypt(struct tls_aes *aes, void *iv, const void *data, size_t len, void *dst) FAST_FUNC; |
networking/tls_aesgcm.c+0 -10
| @@ -136,13 +136,3 @@ void FAST_FUNC aesgcm_GHASH(byte* h, const byte* a, unsigned aSz, const byte* c, | |
| /* Copy the result into s. */ | |
| XMEMCPY(s, x, sSz); | |
| } | |
| - | |
| - | void FAST_FUNC aesgcm_setkey(uint8_t H[16], struct tls_aes *aes, const byte* key, unsigned len) |
| - | { |
| - | byte iv[AES_BLOCK_SIZE]; |
| - | |
| - | aes_setkey(aes, key, len); |
| - | |
| - | memset(iv, 0, AES_BLOCK_SIZE); |
| - | aes_encrypt_one_block(aes, iv, H); |
| - | } |
networking/tls_aesgcm.h+0 -2
| @@ -11,5 +11,3 @@ void aesgcm_GHASH(uint8_t* h, | |
| const uint8_t* c, unsigned cSz, | |
| uint8_t* s, unsigned sSz | |
| ) FAST_FUNC; | |
| - | |
| - | void aesgcm_setkey(uint8_t H[16], struct tls_aes *aes, const uint8_t* key, unsigned len) FAST_FUNC; |