941440cf1
Denys Vlasenko
2018-11-24
Subject
tls: in AES-GCM decoding, avoid memmove
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networking/tls.c +16 -4networking/tls.h +1 -0networking/tls_aesgcm.c +0 -9networking/tls_aesgcm.h +0 -2
networking/tls.c+16 -4
| @@ -343,6 +343,20 @@ void FAST_FUNC tls_get_random(void *buf, unsigned len) | |
| xfunc_die(); | |
| } | |
| + | static void xorbuf3(void *dst, const void *src1, const void *src2, unsigned count) |
| + | { |
| + | uint8_t *d = dst; |
| + | const uint8_t *s1 = src1; |
| + | const uint8_t* s2 = src2; |
| + | while (count--) |
| + | *d++ = *s1++ ^ *s2++; |
| + | } |
| + | |
| + | void FAST_FUNC xorbuf(void *dst, const void *src, unsigned count) |
| + | { |
| + | xorbuf3(dst, dst, src, count); |
| + | } |
| + | |
| /* Nondestructively see the current hash value */ | |
| static unsigned sha_peek(md5sha_ctx_t *ctx, void *buffer) | |
| { | |
| @@ -941,7 +955,6 @@ static void tls_aesgcm_decrypt(tls_state_t *tls, uint8_t *buf, int size) | |
| memcpy(nonce, tls->server_write_IV, 4); | |
| memcpy(nonce + 4, buf, 8); | |
| - | buf += 8; |
| cnt = 1; | |
| remaining = size; | |
| @@ -952,12 +965,12 @@ static void tls_aesgcm_decrypt(tls_state_t *tls, uint8_t *buf, int size) | |
| COUNTER(nonce) = htonl(cnt); /* yes, first cnt here is 2 (!) */ | |
| aes_encrypt_one_block(&tls->aes_decrypt, nonce, scratch); | |
| n = remaining > AES_BLOCK_SIZE ? AES_BLOCK_SIZE : remaining; | |
| - | xorbuf(buf, scratch, n); |
| + | xorbuf3(buf, scratch, buf + 8, n); |
| buf += n; | |
| remaining -= n; | |
| } | |
| - | //aesgcm_GHASH(tls->H, aad, tls->outbuf + OUTBUF_PFX, size, authtag); |
| + | //aesgcm_GHASH(tls->H, aad, tls->inbuf + RECHDR_LEN, size, authtag); |
| //COUNTER(nonce) = htonl(1); | |
| //aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch); | |
| //xorbuf(authtag, scratch, sizeof(authtag)); | |
| @@ -1046,7 +1059,6 @@ static int tls_xread_record(tls_state_t *tls, const char *expected) | |
| sz -= 8 + AES_BLOCK_SIZE; /* we will overwrite nonce, drop hash */ | |
| tls_aesgcm_decrypt(tls, p, sz); | |
| - | memmove(p, p + 8, sz); |
| dbg("encrypted size:%u\n", sz); | |
| } else | |
| if (tls->min_encrypted_len_on_read > tls->MAC_size) { | |
networking/tls.h+1 -0
| @@ -81,6 +81,7 @@ typedef int16_t int16; | |
| #define AES_BLOCK_SIZE 16 | |
| void tls_get_random(void *buf, unsigned len) FAST_FUNC; | |
| + | void xorbuf(void* buf, const void* mask, unsigned count) FAST_FUNC; |
| #define matrixCryptoGetPrngData(buf, len, userPtr) (tls_get_random(buf, len), PS_SUCCESS) | |
networking/tls_aesgcm.c+0 -9
| @@ -11,15 +11,6 @@ typedef uint32_t word32; | |
| #define XMEMSET memset | |
| #define XMEMCPY memcpy | |
| - | void FAST_FUNC xorbuf(void* buf, const void* mask, unsigned count) |
| - | { |
| - | word32 i; |
| - | byte* b = (byte*)buf; |
| - | const byte* m = (const byte*)mask; |
| - | for (i = 0; i < count; i++) |
| - | b[i] ^= m[i]; |
| - | } |
| - | |
| /* from wolfssl-3.15.3/wolfcrypt/src/aes.c */ | |
| static ALWAYS_INLINE void FlattenSzInBits(byte* buf, word32 sz) | |
networking/tls_aesgcm.h+0 -2
| @@ -4,8 +4,6 @@ | |
| * Licensed under GPLv2, see file LICENSE in this source tree. | |
| */ | |
| - | void xorbuf(void* buf, const void* mask, unsigned count) FAST_FUNC; |
| - | |
| void aesgcm_GHASH(uint8_t* h, | |
| const uint8_t* a, //unsigned aSz, | |
| const uint8_t* c, unsigned cSz, | |