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Fix IAX2 encryption (really, bug #4500 for reference)

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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6103 65c4cc65-6c06-0410-ace0-fbb531ad65f3
1.2-netsec
Mark Spencer 20 years ago
parent 0313d0b9c5
commit 3916b7e41b
2 changed files with 58 additions and 17 deletions
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58
channels/chan_iax2.c
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@ -3701,7 +3701,14 @@ static void build_enc_keys(const unsigned char *digest, aes_encrypt_ctx *ecx, ae
static void memcpy_decrypt(unsigned char *dst, const unsigned char *src, int len, aes_decrypt_ctx *dcx)
{
/* memcpy(dst, src, len); */
#if 0
/* Debug with "fake encryption" */
int x;
if (len % 16)
ast_log(LOG_WARNING, "len should be multiple of 16, not %d!\n", len);
for (x=0;x<len;x++)
dst[x] = src[x] ^ 0xff;
#else
unsigned char lastblock[16] = { 0 };
int x;
while(len > 0) {
@ -3713,11 +3720,19 @@ static void memcpy_decrypt(unsigned char *dst, const unsigned char *src, int len
src += 16;
len -= 16;
}
#endif
}
static void memcpy_encrypt(unsigned char *dst, const unsigned char *src, int len, aes_encrypt_ctx *ecx)
{
/* memcpy(dst, src, len); */
#if 0
/* Debug with "fake encryption" */
int x;
if (len % 16)
ast_log(LOG_WARNING, "len should be multiple of 16, not %d!\n", len);
for (x=0;x<len;x++)
dst[x] = src[x] ^ 0xff;
#else
unsigned char curblock[16] = { 0 };
int x;
while(len > 0) {
@ -3729,6 +3744,7 @@ static void memcpy_encrypt(unsigned char *dst, const unsigned char *src, int len
src += 16;
len -= 16;
}
#endif
}
static int decode_frame(aes_decrypt_ctx *dcx, struct ast_iax2_full_hdr *fh, struct ast_frame *f, int *datalen)
@ -3740,15 +3756,17 @@ static int decode_frame(aes_decrypt_ctx *dcx, struct ast_iax2_full_hdr *fh, stru
return -1;
if (ntohs(fh->scallno) & IAX_FLAG_FULL) {
struct ast_iax2_full_enc_hdr *efh = (struct ast_iax2_full_enc_hdr *)fh;
if (option_debug)
ast_log(LOG_DEBUG, "Decoding full frame with length %d\n", *datalen);
if (*datalen < 16 + sizeof(struct ast_iax2_full_hdr))
return -1;
padding = 16 + (efh->encdata[15] & 0xf);
/* Decrypt */
memcpy_decrypt(workspace, efh->encdata, *datalen - sizeof(struct ast_iax2_full_enc_hdr), dcx);
padding = 16 + (workspace[15] & 0xf);
if (option_debug)
ast_log(LOG_DEBUG, "Decoding full frame with length %d (padding = %d) (15=%02x)\n", *datalen, padding, workspace[15]);
if (*datalen < padding + sizeof(struct ast_iax2_full_hdr))
return -1;
/* Decrypt */
memcpy_decrypt(workspace, efh->encdata, *datalen, dcx);
*datalen -= padding;
memcpy(efh->encdata, workspace + padding, *datalen - sizeof(struct ast_iax2_full_enc_hdr));
f->frametype = fh->type;
@ -3763,11 +3781,11 @@ static int decode_frame(aes_decrypt_ctx *dcx, struct ast_iax2_full_hdr *fh, stru
ast_log(LOG_DEBUG, "Decoding mini with length %d\n", *datalen);
if (*datalen < 16 + sizeof(struct ast_iax2_mini_hdr))
return -1;
padding = 16 + (efh->encdata[15] & 0x0f);
/* Decrypt */
memcpy_decrypt(workspace, efh->encdata, *datalen - sizeof(struct ast_iax2_mini_enc_hdr), dcx);
padding = 16 + (workspace[15] & 0x0f);
if (*datalen < padding + sizeof(struct ast_iax2_mini_hdr))
return -1;
/* Decrypt */
memcpy_decrypt(workspace, efh->encdata, *datalen, dcx);
*datalen -= padding;
memcpy(efh->encdata, workspace + padding, *datalen - sizeof(struct ast_iax2_mini_enc_hdr));
}
@ -3784,15 +3802,17 @@ static int encrypt_frame(aes_encrypt_ctx *ecx, struct ast_iax2_full_hdr *fh, uns
if (ntohs(fh->scallno) & IAX_FLAG_FULL) {
struct ast_iax2_full_enc_hdr *efh = (struct ast_iax2_full_enc_hdr *)fh;
if (option_debug)
ast_log(LOG_DEBUG, "Encoding full frame with length %d\n", *datalen);
ast_log(LOG_DEBUG, "Encoding full frame %d/%d with length %d\n", fh->type, fh->csub, *datalen);
padding = 16 - ((*datalen - sizeof(struct ast_iax2_full_enc_hdr)) % 16);
padding = 16 + (padding & 0xf);
memcpy(workspace, poo, padding);
memcpy(workspace + padding, efh->encdata, *datalen - sizeof(struct ast_iax2_full_enc_hdr));
*datalen += padding;
workspace[15] &= 0xf0;
workspace[15] |= (padding & 0xf);
memcpy_encrypt(efh->encdata, workspace, *datalen, ecx);
if (option_debug)
ast_log(LOG_DEBUG, "Encoding full frame %d/%d with length %d + %d padding (15=%02x)\n", fh->type, fh->csub, *datalen, padding, workspace[15]);
*datalen += padding;
memcpy_encrypt(efh->encdata, workspace, *datalen - sizeof(struct ast_iax2_full_enc_hdr), ecx);
if (*datalen >= 32 + sizeof(struct ast_iax2_full_enc_hdr))
memcpy(poo, workspace + *datalen - 32, 32);
} else {
@ -3801,12 +3821,12 @@ static int encrypt_frame(aes_encrypt_ctx *ecx, struct ast_iax2_full_hdr *fh, uns
ast_log(LOG_DEBUG, "Encoding mini frame with length %d\n", *datalen);
padding = 16 - ((*datalen - sizeof(struct ast_iax2_mini_enc_hdr)) % 16);
padding = 16 + (padding & 0xf);
memset(workspace, 0, padding);
memcpy(workspace, poo, padding);
memcpy(workspace + padding, efh->encdata, *datalen - sizeof(struct ast_iax2_mini_enc_hdr));
workspace[15] &= 0xf0;
workspace[15] |= (padding & 0x0f);
*datalen += padding;
memcpy_encrypt(efh->encdata, workspace, *datalen, ecx);
memcpy_encrypt(efh->encdata, workspace, *datalen - sizeof(struct ast_iax2_mini_enc_hdr), ecx);
if (*datalen >= 32 + sizeof(struct ast_iax2_mini_enc_hdr))
memcpy(poo, workspace + *datalen - 32, 32);
}
@ -3955,6 +3975,12 @@ static int iax2_send(struct chan_iax2_pvt *pvt, struct ast_frame *f, unsigned in
pvt->svideoformat = f->subclass & ~0x1;
if (ast_test_flag(pvt, IAX_ENCRYPTED)) {
if (ast_test_flag(pvt, IAX_KEYPOPULATED)) {
if (iaxdebug) {
if (fr->transfer)
iax_showframe(fr, NULL, 2, &pvt->transfer, fr->datalen - sizeof(struct ast_iax2_full_hdr));
else
iax_showframe(fr, NULL, 2, &pvt->addr, fr->datalen - sizeof(struct ast_iax2_full_hdr));
}
encrypt_frame(&pvt->ecx, fh, pvt->semirand, &fr->datalen);
} else
ast_log(LOG_WARNING, "Supposed to send packet encrypted, but no key?\n");
@ -6359,7 +6385,7 @@ static int socket_read(int *id, int fd, short events, void *cbdata)
}
#ifdef DEBUG_SUPPORT
else if (iaxdebug)
iax_showframe(NULL, fh, 1, &sin, res - sizeof(struct ast_iax2_full_hdr));
iax_showframe(NULL, fh, 3, &sin, res - sizeof(struct ast_iax2_full_hdr));
#endif
}

17
channels/iax2-parser.c
Unescape View File

@ -440,8 +440,23 @@ void iax_showframe(struct iax_frame *f, struct ast_iax2_full_hdr *fhi, int rx, s
char subclass2[20];
char *class;
char *subclass;
char *dir;
char tmp[256];
char iabuf[INET_ADDRSTRLEN];
switch(rx) {
case 0:
dir = "Tx";
break;
case 2:
dir = "TE";
break;
case 3:
dir = "RD";
break;
default:
dir = "Rx";
break;
}
if (f) {
fh = f->data;
snprintf(retries, (int)sizeof(retries), "%03d", f->retries);
@ -485,7 +500,7 @@ void iax_showframe(struct iax_frame *f, struct ast_iax2_full_hdr *fhi, int rx, s
}
snprintf(tmp, (int)sizeof(tmp),
"%s-Frame Retry[%s] -- OSeqno: %3.3d ISeqno: %3.3d Type: %s Subclass: %s\n",
(rx ? "Rx" : "Tx"),
dir,
retries, fh->oseqno, fh->iseqno, class, subclass);
outputf(tmp);
snprintf(tmp, (int)sizeof(tmp),

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