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Additional sanity checks for QNX + CAAM resource manager #11263

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7d3eb2c
additional sanity checks on AES input arguments with QNX resource man…
JacobBarthelmeh Aug 25, 2026
a4fc688
additional sanity checks on CMAC input arguments with QNX resource ma…
JacobBarthelmeh Aug 25, 2026
58459e8
remove check on if input length is 0
JacobBarthelmeh Aug 31, 2026
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128 changes: 106 additions & 22 deletions wolfcrypt/src/port/caam/caam_qnx.c
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,23 @@ sem_t localMemSem;
#define WOLFSSL_CAAM_QNX_MEMORY 250000
#endif

/* Maximum input size accepted for a single operation. Sizes are taken from the
* device client and are not trusted, this bounds them so that the aggregate
* buffer sizes calculated from them can not overflow. */
#ifndef WOLFSSL_CAAM_QNX_MAX_SZ
#define WOLFSSL_CAAM_QNX_MAX_SZ (16 * 1024 * 1024)
#endif

/* Permissions that the /dev/wolfCrypt device node is created with. Any process
* that can open the device is able to submit operations to it, which is the
* intended use case of the resource manager, offering the CAAM to unprivileged
* applications. Requests are treated as untrusted and sanity checked before
* use. Deployments that instead want the CAAM reserved for privileged callers
* should override this, i.e. 0600 or 0660 with a dedicated group. */
#ifndef WOLFSSL_CAAM_QNX_DEV_MODE
#define WOLFSSL_CAAM_QNX_DEV_MODE 0666
#endif
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/* keep track of which ID memory belongs to so it can be free'd up */
#define MAX_PART 7
pthread_mutex_t sm_mutex;
Expand Down Expand Up @@ -357,24 +374,47 @@ static int doCMAC(resmgr_context_t *ctp, io_devctl_t *msg, unsigned int args[4],
CAAM_BUFFER tmp[3];
iov_t in_iovs[3], out_iov;

int msgSz = 0, ret, numBuf, keySz;
int msgSz = 0, ret, numBuf, keySz, expSz;
unsigned char ctx[32]; /* running CMAC context is a constant 32 bytes */
unsigned char keybuf[32 + BLACK_KEY_MAC_SZ];/*max AES key size is 32 + MAC*/
unsigned char *buf = NULL;

numBuf = 2; /* start with 2 (key + ctx) for case with no msg input */
keySz = args[1];
if (args[2] == 1) { /* is it a black key? */

/* The sizes here come from the device client and are not trusted. The key
* size is used as the length to read into the fixed size keybuf, check
* that it is a valid AES key size before using it. */
keySz = args[1];
if (keySz != 16 && keySz != 24 && keySz != 32) {
WOLFSSL_MSG("Bad CMAC key size found");
return EBADMSG;
}

/* Is it a black key? This is not a boolean, it carries the black key type
* (CAAM_BLACK_KEY_SM / _CCM / _ECB), so test it the same way caamAesCmac
* does. Matching its non-zero test keeps the amount read here equal to the
* amount the descriptor consumes for any type. If a client sends a type
* that it did not append the MAC for, the short read is caught below. */
if (args[2] != 0) {
keySz = keySz + BLACK_KEY_MAC_SZ;
}
SETIOV(&in_iovs[0], keybuf, keySz);
SETIOV(&in_iovs[1], ctx, sizeof(ctx));
msgSz = args[3];
if (msgSz < 0) {
WOLFSSL_MSG("CMAC msg size was a negative value");

/* the key sizes accepted above always fit, this guards against keybuf
* being resized without the check above getting updated */
if (keySz > (int)sizeof(keybuf)) {
WOLFSSL_MSG("CMAC key size larger than key buffer");
return EBADMSG;
}

if (args[3] > WOLFSSL_CAAM_QNX_MAX_SZ) {
WOLFSSL_MSG("CMAC msg size out of range");
return EBADMSG;
}
msgSz = (int)args[3];

SETIOV(&in_iovs[0], keybuf, keySz);
SETIOV(&in_iovs[1], ctx, sizeof(ctx));

if (msgSz > 0) {
buf = (unsigned char*)CAAM_ADR_MAP(0, msgSz, 0);
if (buf == NULL) {
Expand All @@ -384,9 +424,20 @@ static int doCMAC(resmgr_context_t *ctp, io_devctl_t *msg, unsigned int args[4],
numBuf = numBuf + 1; /* increase buffer size by one when adding msg */
}

expSz = msgSz + keySz + (int)sizeof(ctx);
ret = resmgr_msgreadv(ctp, in_iovs, numBuf, idx);
if (ret < (msgSz + keySz + sizeof(ctx))) {
/* sanity check that enough data was sent */
if (ret < 0) {
/* the read itself failed */
WOLFSSL_MSG("error reading input for CMAC operation");
if (buf != NULL)
CAAM_ADR_UNMAP(buf, 0, msgSz, 0);
return ECANCELED;
}

if (ret < expSz) {
/* sanity check that enough data was sent, otherwise part of the
* buffers would be left holding data from a previous operation */
WOLFSSL_MSG("not enough input data sent for CMAC operation");
if (buf != NULL)
CAAM_ADR_UNMAP(buf, 0, msgSz, 0);
return EOVERFLOW;
Expand Down Expand Up @@ -755,39 +806,64 @@ static int doAES(resmgr_context_t *ctp, io_devctl_t *msg, unsigned int args[4],
iov_t in_iovs[6], out_iovs[2];
int inIdx = 0, outIdx = 0;
int algo;
int readSz;
unsigned char *key = NULL, *iv = NULL, *in = NULL, *out = NULL;
unsigned char *pt = NULL;
int keySz, ivSz = 0, inSz, outSz;
unsigned int totalSz;
unsigned int phyMem = 0;
int useLocalMem = 0;

memset(tmp, 0, sizeof(tmp));

/* get key info */
/* The sizes here come from the device client and are not trusted. Sanity
* check them before doing any size arithmetic or pointer math. The key
* size is required to be a valid AES key size, which is also enforced
* later on by caamAesInternal, and the input size is bounded so that the
* aggregate size below can not overflow and wrongly select the fixed size
* local memory mapping. */
keySz = args[1] & 0xFFFF; /* key size */
inSz = args[2]; /* input size */
outSz = args[2]; /* output size */
if (keySz != 16 && keySz != 24 && keySz != 32) {
WOLFSSL_MSG("Bad AES key size found");
return EBADMSG;
}

if (args[2] > WOLFSSL_CAAM_QNX_MAX_SZ) {
WOLFSSL_MSG("AES input size out of range");
return EBADMSG;
}
inSz = (int)args[2]; /* input size */
outSz = (int)args[2]; /* output size */

if (type == WC_CAAM_AESCBC || type == WC_CAAM_AESCTR) {
ivSz = 16;
}

if (keySz + inSz + outSz + ivSz < WOLFSSL_CAAM_QNX_MEMORY) {
totalSz = (unsigned int)keySz + (unsigned int)inSz +
(unsigned int)outSz + (unsigned int)ivSz;

if (totalSz < WOLFSSL_CAAM_QNX_MEMORY) {
if (sem_trywait(&localMemSem) == 0) {
key = localMemory;
phyMem = localPhy;
useLocalMem = 1;
}
}

/* local pre-mapped memory was not used, try to map some memory now */
if (key == NULL) {
pt = (unsigned char*)CAAM_ADR_MAP(0, keySz + inSz + outSz + ivSz, 0);
pt = (unsigned char*)CAAM_ADR_MAP(0, totalSz, 0);
key = pt;
}

if (key == NULL) {
ret = ECANCELED;
}
SETIOV(&in_iovs[inIdx], key, keySz);
inIdx++;

if (ret == EOK) {
SETIOV(&in_iovs[inIdx], key, keySz);
inIdx++;
}

/* check for IV */
if (ret == EOK) {
Expand Down Expand Up @@ -821,9 +897,16 @@ static int doAES(resmgr_context_t *ctp, io_devctl_t *msg, unsigned int args[4],
}

if (ret == EOK) {
if (resmgr_msgreadv(ctp, in_iovs, inIdx, idx) < 0) {
readSz = resmgr_msgreadv(ctp, in_iovs, inIdx, idx);
if (readSz < 0) {
ret = ECANCELED;
}
else if (readSz < (keySz + ivSz + inSz)) {
/* sanity check that enough data was sent, otherwise part of the
* buffer would be left holding data from a previous operation */
WOLFSSL_MSG("not enough input data sent for AES operation");
ret = EOVERFLOW;
}
}

if (ret == EOK) {
Expand Down Expand Up @@ -863,7 +946,7 @@ static int doAES(resmgr_context_t *ctp, io_devctl_t *msg, unsigned int args[4],

/* sync the new IV/MAC and output buffer */
if (ret == EOK) {
CAAM_ADR_SYNC(key, keySz + inSz + ivSz + outSz);
CAAM_ADR_SYNC(key, totalSz);
if (type == WC_CAAM_AESCBC || type == WC_CAAM_AESCTR) {
SETIOV(&out_iovs[1], iv, ivSz);
outIdx++;
Expand All @@ -877,9 +960,10 @@ static int doAES(resmgr_context_t *ctp, io_devctl_t *msg, unsigned int args[4],
}

if (pt != NULL) {
CAAM_ADR_UNMAP(pt, 0, keySz + inSz + outSz + ivSz, 0);
CAAM_ADR_UNMAP(pt, 0, totalSz, 0);
}
else {

if (useLocalMem) {
/* done using local mapped memory */
sem_post(&localMemSem);
}
Expand Down Expand Up @@ -1738,7 +1822,7 @@ int main(int argc, char *argv[])
io_funcs.write = io_write;
io_funcs.devctl = io_devctl;

iofunc_attr_init (&ioattr, S_IFCHR | 0666, NULL, NULL);
iofunc_attr_init (&ioattr, S_IFCHR | WOLFSSL_CAAM_QNX_DEV_MODE, NULL, NULL);
name = resmgr_attach(dpp, &rattr, "/dev/wolfCrypt",
_FTYPE_ANY, 0, &connect_funcs, &io_funcs, &ioattr);
if (name == -1) {
Expand Down
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