diff options
| -rw-r--r-- | networking/tls.c | 25 |
1 files changed, 11 insertions, 14 deletions
diff --git a/networking/tls.c b/networking/tls.c index 55ad2d83f..fb49b1523 100644 --- a/networking/tls.c +++ b/networking/tls.c @@ -539,7 +539,7 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) xhdr->type = type; xhdr->proto_maj = TLS_MAJ; xhdr->proto_min = TLS_MIN; - /* fake unencrypted record header len for MAC calculation */ + /* fake unencrypted record len for MAC calculation */ xhdr->len16_hi = size >> 8; xhdr->len16_lo = size & 0xff; @@ -634,7 +634,7 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) // AES_128_CBC Block 16 16 16 // AES_256_CBC Block 32 16 16 - /* Build IV+content+MAC+padding in outbuf */ + /* Fill IV and padding in outbuf */ tls_get_random(buf - AES_BLOCKSIZE, AES_BLOCKSIZE); /* IV */ dbg("before crypt: 5 hdr + %u data + %u hash bytes\n", size, SHA256_OUTSIZE); // RFC is talking nonsense: @@ -654,7 +654,7 @@ static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type) // It's ok to have more than minimum padding, but we do minimum. padding_length = (~size) & (AES_BLOCKSIZE - 1); do { - buf[size++] = padding_length; /* padding */ + buf[size++] = padding_length; /* padding */ } while ((size & (AES_BLOCKSIZE - 1)) != 0); /* Encrypt content+MAC+padding in place */ @@ -796,26 +796,23 @@ static int tls_xread_record(tls_state_t *tls) ) { bb_error_msg_and_die("bad encrypted len:%u", sz); } - /* Decrypt content+MAC+padding in place */ + /* Decrypt content+MAC+padding, moving it over IV in the process */ psAesInit(&ctx, p, /* IV */ tls->server_write_key, sizeof(tls->server_write_key) ); + sz -= AES_BLOCKSIZE; /* we will overwrite IV now */ psAesDecrypt(&ctx, p + AES_BLOCKSIZE, /* ciphertext */ - p + AES_BLOCKSIZE, /* plaintext */ - sz - AES_BLOCKSIZE + p, /* plaintext */ + sz ); padding_len = p[sz - 1]; - dbg("encrypted size:%u type:0x%02x padding_length:0x%02x\n", sz, p[AES_BLOCKSIZE], padding_len); + dbg("encrypted size:%u type:0x%02x padding_length:0x%02x\n", sz, p[0], padding_len); padding_len++; - sz -= AES_BLOCKSIZE + SHA256_OUTSIZE + padding_len; + sz -= SHA256_OUTSIZE + padding_len; /* drop MAC and padding */ if (sz < 0) { bb_error_msg_and_die("bad padding size:%u", padding_len); } - if (sz != 0) { - /* Skip IV */ - memmove(tls->inbuf + RECHDR_LEN, tls->inbuf + RECHDR_LEN + AES_BLOCKSIZE, sz); - } } else { /* if nonzero, then it's TLS_RSA_WITH_NULL_SHA256: drop MAC */ /* else: no encryption yet on input, subtract zero = NOP */ @@ -828,8 +825,8 @@ static int tls_xread_record(tls_state_t *tls) if (xhdr->type == RECORD_TYPE_ALERT && sz >= 2) { uint8_t *p = tls->inbuf + RECHDR_LEN; dbg("ALERT size:%d level:%d description:%d\n", sz, p[0], p[1]); - if (p[0] == 1) { /*warning */ - if (p[1] == 0) { /* warning, close_notify: EOF */ + if (p[0] == 1) { /* warning */ + if (p[1] == 0) { /* "close_notify" warning: it's EOF */ dbg("EOF (TLS encoded) from peer\n"); sz = 0; goto end; |