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Merged
SparkiDev merged 1 commit into from
Nov 6, 2026
Merged

Always run RSA software cleanup after free callback #12028

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105 changes: 105 additions & 0 deletions tests/api/test_rsa.c
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Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,7 @@ int test_wc_InitRsaKey(void)

/* Test bad args. */
ExpectIntEQ(wc_InitRsaKey(NULL, HEAP_HINT), WC_NO_ERR_TRACE(BAD_FUNC_ARG));
ExpectIntEQ(wc_FreeRsaKey(NULL), WC_NO_ERR_TRACE(BAD_FUNC_ARG));

DoExpectIntEQ(wc_FreeRsaKey(&key), 0);
#endif
Expand Down Expand Up @@ -2714,3 +2715,107 @@ int test_wc_RsaOaep_EncryptFailureWipe(void)
#endif
return EXPECT_RESULT();
}

#if !defined(NO_RSA) && defined(WOLF_CRYPTO_CB) && \
defined(WOLF_CRYPTO_CB_FREE) && !defined(WOLFSSL_RSA_PUBLIC_ONLY) && \
(defined(USE_CERT_BUFFERS_1024) || defined(USE_CERT_BUFFERS_2048)) && \
!defined(HAVE_FIPS) && !defined(HAVE_SELFTEST)
#define TEST_RSA_CB_FREE
#define TEST_RSA_CB_FREE_DEVID 0x52534146 /* "RSAF" */

typedef struct {
int frees; /* RSA free callbacks seen */
int ret; /* what the callback returns */
} RsaCbFreeCtx;

/* Device that never wipes the software key fields on free. */
static int rsa_cb_free_cb(int devIdArg, wc_CryptoInfo* info, void* ctx)
{
RsaCbFreeCtx* seen = (RsaCbFreeCtx*)ctx;

(void)devIdArg;

if ((seen != NULL) && (info != NULL) &&
(info->algo_type == WC_ALGO_TYPE_FREE) &&
(info->free.algo == WC_ALGO_TYPE_PK) &&
(info->free.type == WC_PK_TYPE_RSA)) {
seen->frees++;
return seen->ret;
}
return WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE);
}
#endif

/*
* Testing wc_FreeRsaKey() wipes the key whatever the free callback returns.
*/
int test_wc_FreeRsaKey_CryptoCb(void)
{
EXPECT_DECLS;
#ifdef TEST_RSA_CB_FREE
RsaKey key;
RsaCbFreeCtx seen;
const byte* der;
word32 derSz;
word32 idx;
int cbRet[4];
int wantRet[4];
int devId;
int freeRet;
int i;

#ifdef USE_CERT_BUFFERS_1024
der = client_key_der_1024;
derSz = (word32)sizeof_client_key_der_1024;
#else
der = client_key_der_2048;
derSz = (word32)sizeof_client_key_der_2048;
#endif

/* device handles it, device fails, device declines, no device */
cbRet[0] = 0;
wantRet[0] = 0;
cbRet[1] = WC_NO_ERR_TRACE(WC_HW_E);
wantRet[1] = WC_NO_ERR_TRACE(WC_HW_E);
cbRet[2] = WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE);
wantRet[2] = 0;
cbRet[3] = 0;
wantRet[3] = 0;

XMEMSET(&seen, 0, sizeof(seen));
ExpectIntEQ(wc_CryptoCb_RegisterDevice(TEST_RSA_CB_FREE_DEVID,
rsa_cb_free_cb, &seen), 0);

for (i = 0; i < 4; i++) {
devId = (i < 3) ? TEST_RSA_CB_FREE_DEVID : INVALID_DEVID;
seen.frees = 0;
seen.ret = cbRet[i];
idx = 0;
XMEMSET(&key, 0, sizeof(key));

ExpectIntEQ(wc_InitRsaKey_ex(&key, HEAP_HINT, devId), 0);
ExpectIntEQ(wc_RsaPrivateKeyDecode(der, &idx, &key, derSz), 0);
ExpectFalse(mp_iszero(&key.d));

freeRet = wc_FreeRsaKey(&key);
ExpectIntEQ(freeRet, wantRet[i]);
#ifndef WOLF_CRYPTO_CB_FIND
ExpectIntEQ(seen.frees, (devId == INVALID_DEVID) ? 0 : 1);
#endif
ExpectTrue(mp_iszero(&key.d));
ExpectTrue(mp_iszero(&key.p));
ExpectTrue(mp_iszero(&key.q));
#if defined(WOLFSSL_KEY_GEN) || defined(OPENSSL_EXTRA) || \
!defined(RSA_LOW_MEM)
ExpectTrue(mp_iszero(&key.dP));
ExpectTrue(mp_iszero(&key.dQ));
ExpectTrue(mp_iszero(&key.u));
#endif
ExpectTrue(mp_iszero(&key.n));
ExpectTrue(mp_iszero(&key.e));
}

wc_CryptoCb_UnRegisterDevice(TEST_RSA_CB_FREE_DEVID);
#endif
return EXPECT_RESULT();
}
4 changes: 3 additions & 1 deletion tests/api/test_rsa.h
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Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,7 @@ int test_wc_RsaFeatureCoverage(void);
int test_wc_CryptoCb_RsaPssVerify(void);
int test_wc_CryptoCb_RsaPssVerifyRecover(void);
int test_wc_MakeRsaKey_id_dev(void);
int test_wc_FreeRsaKey_CryptoCb(void);

#define TEST_RSA_DECLS \
TEST_DECL_GROUP("rsa", test_wc_InitRsaKey), \
Expand Down Expand Up @@ -83,6 +84,7 @@ int test_wc_MakeRsaKey_id_dev(void);
TEST_DECL_GROUP("rsa", test_wc_RsaFeatureCoverage), \
TEST_DECL_GROUP("rsa", test_wc_CryptoCb_RsaPssVerify), \
TEST_DECL_GROUP("rsa", test_wc_CryptoCb_RsaPssVerifyRecover), \
TEST_DECL_GROUP("rsa", test_wc_MakeRsaKey_id_dev)
TEST_DECL_GROUP("rsa", test_wc_MakeRsaKey_id_dev), \
TEST_DECL_GROUP("rsa", test_wc_FreeRsaKey_CryptoCb)

#endif /* WOLFCRYPT_TEST_RSA_H */
14 changes: 6 additions & 8 deletions wolfcrypt/src/rsa.c
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Original file line number Diff line number Diff line change
Expand Up @@ -614,14 +614,12 @@ int wc_FreeRsaKey(RsaKey* key)
if (key->devId != INVALID_DEVID)
#endif
{
ret = wc_CryptoCb_Free(key->devId, WC_ALGO_TYPE_PK,
WC_PK_TYPE_RSA, 0, key);
/* If callback wants standard free, it returns CRYPTOCB_UNAVAILABLE.
* Otherwise assume the callback handled cleanup. */
if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE))
return ret;
/* fall-through to software cleanup */
ret = 0;
int cbRet = wc_CryptoCb_Free(key->devId, WC_ALGO_TYPE_PK,
WC_PK_TYPE_RSA, 0, key);
/* Keep the device status but always run the software cleanup below,
* since private key fields may still hold data. */
if (cbRet != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE))
ret = cbRet;
}
#endif /* WOLF_CRYPTO_CB && WOLF_CRYPTO_CB_FREE */

Expand Down
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