bool _COSE_Enveloped_decrypt(COSE_Enveloped * pcose, COSE_RecipientInfo * pRecip, const byte *pbKeyIn, size_t cbKeyIn, const char * szContext, cose_errback * perr)
{
int alg;
const cn_cbor * cn = NULL;
byte * pbKey = NULL;
size_t cbitKey = 0;
#ifdef USE_CBOR_CONTEXT
cn_cbor_context * context;
#endif
byte * pbAuthData = NULL;
size_t cbAuthData;
#ifdef USE_CBOR_CONTEXT
context = &pcose->m_message.m_allocContext;
#endif
CHECK_CONDITION(!((pRecip != NULL) && (pbKeyIn != NULL)), COSE_ERR_INTERNAL);
cn = _COSE_map_get_int(&pcose->m_message, COSE_Header_Algorithm, COSE_BOTH, perr);
if (cn == NULL) {
error:
errorReturn:
if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);
if ((pbKey != NULL) && (pbKeyIn == NULL)) {
memset(pbKey, 0xff, cbitKey / 8);
COSE_FREE(pbKey, context);
}
return false;
}
CHECK_CONDITION((cn->type == CN_CBOR_UINT) || (cn->type == CN_CBOR_INT), COSE_ERR_INVALID_PARAMETER);
alg = (int) cn->v.uint;
switch (alg) {
#ifdef USE_AES_CCM_16_64_128
case COSE_Algorithm_AES_CCM_16_64_128:
cbitKey = 128;
break;
#endif
#ifdef USE_AES_CCM_16_128_128
case COSE_Algorithm_AES_CCM_16_128_128:
cbitKey = 128;
break;
#endif
#ifdef USE_AES_CCM_64_64_128
case COSE_Algorithm_AES_CCM_64_64_128:
cbitKey = 128;
break;
#endif
#ifdef USE_AES_CCM_64_128_128
case COSE_Algorithm_AES_CCM_64_128_128:
cbitKey = 128;
break;
#endif
#ifdef USE_AES_CCM_64_64_256
case COSE_Algorithm_AES_CCM_64_64_256:
cbitKey = 256;
break;
#endif
#ifdef USE_AES_CCM_16_128_256
case COSE_Algorithm_AES_CCM_16_128_256:
cbitKey = 256;
break;
#endif
#ifdef USE_AES_CCM_64_128_256
case COSE_Algorithm_AES_CCM_64_128_256:
cbitKey = 256;
break;
#endif
#ifdef USE_AES_CCM_16_64_256
case COSE_Algorithm_AES_CCM_16_64_256:
cbitKey = 256;
break;
#endif
#ifdef USE_AES_GCM_128
case COSE_Algorithm_AES_GCM_128:
cbitKey = 128;
break;
#endif
#ifdef USE_AES_GCM_192
case COSE_Algorithm_AES_GCM_192:
cbitKey = 192;
break;
#endif
#ifdef USE_AES_GCM_256
case COSE_Algorithm_AES_GCM_256:
cbitKey = 256;
break;
#endif
default:
FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
break;
}
//
// We are doing the enveloped item - so look for the passed in recipient
//
if (pbKeyIn != NULL) {
CHECK_CONDITION(cbKeyIn == cbitKey / 8, COSE_ERR_INVALID_PARAMETER);
pbKey = pbKeyIn;
}
else {
// Allocate the key if we have not already done so
if (pbKey == NULL) {
pbKey = COSE_CALLOC(cbitKey / 8, 1, context);
CHECK_CONDITION(pbKey != NULL, COSE_ERR_OUT_OF_MEMORY);
}
// If there is a recipient - ask it for the key
if (pRecip != NULL) {
COSE_RecipientInfo * pRecipX;
for (pRecipX = pcose->m_recipientFirst; pRecipX != NULL; pRecipX = pRecipX->m_recipientNext) {
if (pRecipX == pRecip) {
if (!_COSE_Recipient_decrypt(pRecipX, pRecip, alg, cbitKey, pbKey, perr)) goto errorReturn;
break;
}
else if (pRecipX->m_encrypt.m_recipientFirst != NULL) {
if (_COSE_Recipient_decrypt(pRecipX, pRecip, alg, cbitKey, pbKey, perr)) break;
}
}
CHECK_CONDITION(pRecipX != NULL, COSE_ERR_NO_RECIPIENT_FOUND);
}
else {
for (pRecip = pcose->m_recipientFirst; pRecip != NULL; pRecip = pRecip->m_recipientNext) {
if (_COSE_Recipient_decrypt(pRecip, NULL, alg, cbitKey, pbKey, perr)) break;
}
CHECK_CONDITION(pRecip != NULL, COSE_ERR_NO_RECIPIENT_FOUND);
}
}
// Build authenticated data
if (!_COSE_Encrypt_Build_AAD(&pcose->m_message, &pbAuthData, &cbAuthData, szContext, perr)) goto errorReturn;
cn = _COSE_arrayget_int(&pcose->m_message, INDEX_BODY);
CHECK_CONDITION(cn != NULL, COSE_ERR_INVALID_PARAMETER);
switch (alg) {
#ifdef USE_AES_CCM_16_64_128
case COSE_Algorithm_AES_CCM_16_64_128:
if (!AES_CCM_Decrypt(pcose, 64, 16, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_CCM_16_64_256
case COSE_Algorithm_AES_CCM_16_64_256:
if (!AES_CCM_Decrypt(pcose, 64, 16, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_CCM_16_128_128
case COSE_Algorithm_AES_CCM_16_128_128:
if (!AES_CCM_Decrypt(pcose, 128, 16, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_CCM_16_128_256
case COSE_Algorithm_AES_CCM_16_128_256:
if (!AES_CCM_Decrypt(pcose, 128, 16, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_CCM_64_64_128
case COSE_Algorithm_AES_CCM_64_64_128:
if (!AES_CCM_Decrypt(pcose, 64, 64, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_CCM_64_64_256
case COSE_Algorithm_AES_CCM_64_64_256:
if (!AES_CCM_Decrypt(pcose, 64, 64, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_CCM_64_128_128
case COSE_Algorithm_AES_CCM_64_128_128:
if (!AES_CCM_Decrypt(pcose, 128, 64, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_CCM_64_128_256
case COSE_Algorithm_AES_CCM_64_128_256:
if (!AES_CCM_Decrypt(pcose, 128, 64, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_GCM_128
case COSE_Algorithm_AES_GCM_128:
if (!AES_GCM_Decrypt(pcose, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_GCM_192
case COSE_Algorithm_AES_GCM_192:
if (!AES_GCM_Decrypt(pcose, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
#ifdef USE_AES_GCM_256
case COSE_Algorithm_AES_GCM_256:
if (!AES_GCM_Decrypt(pcose, pbKey, cbitKey / 8, cn->v.bytes, cn->length, pbAuthData, cbAuthData, perr)) goto error;
break;
#endif
default:
FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
break;
}
if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);
if ((pbKey != NULL) && (pbKeyIn == NULL)) COSE_FREE(pbKey, context);
if (perr != NULL) perr->err = COSE_ERR_NONE;
return true;
}
bool COSE_Mac_validate(HCOSE_MAC h, HCOSE_RECIPIENT hRecip, cose_errback * perr)
{
COSE_MacMessage * pcose = (COSE_MacMessage *)h;
COSE_RecipientInfo * pRecip = (COSE_RecipientInfo *)hRecip;
cn_cbor_errback cbor_error;
byte * pbAuthData = NULL;
int cbitKey = 0;
int alg;
const cn_cbor * cn = NULL;
byte * pbKey = NULL;
#ifdef USE_CBOR_CONTEXT
cn_cbor_context * context = NULL;
#endif
ssize_t cbAuthData;
cn_cbor * pAuthData = NULL;
cn_cbor * ptmp = NULL;
CHECK_CONDITION(IsValidMacHandle(h) && IsValidRecipientHandle(hRecip), COSE_ERR_INVALID_PARAMETER);
#ifdef USE_CBOR_CONTEXT
context = &pcose->m_message.m_allocContext;
#endif
cn = _COSE_map_get_int(&pcose->m_message, COSE_Header_Algorithm, COSE_BOTH, perr);
if (cn == NULL) goto errorReturn;
if (cn->type == CN_CBOR_TEXT) {
FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
}
else {
CHECK_CONDITION((cn->type == CN_CBOR_UINT || cn->type == CN_CBOR_INT), COSE_ERR_INVALID_PARAMETER);
alg = (int)cn->v.uint;
switch (alg) {
case COSE_Algorithm_CBC_MAC_128_64:
case COSE_Algorithm_CBC_MAC_128_128:
cbitKey = 128;
break;
case COSE_Algorithm_CBC_MAC_256_64:
case COSE_Algorithm_CBC_MAC_256_128:
case COSE_Algorithm_HMAC_256_64:
case COSE_Algorithm_HMAC_256_256:
cbitKey = 256;
break;
case COSE_Algorithm_HMAC_384_384:
cbitKey = 384;
break;
case COSE_Algorithm_HMAC_512_512:
cbitKey = 512;
break;
default:
FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
break;
}
}
// Allocate the key if we have not already done so
if (pbKey == NULL) {
pbKey = COSE_CALLOC(cbitKey / 8, 1, context);
CHECK_CONDITION(pbKey != NULL, COSE_ERR_OUT_OF_MEMORY);
}
// If there is a recipient - ask it for the key
for (pRecip = pcose->m_recipientFirst; pRecip != NULL; pRecip = pRecip->m_recipientNext) {
if (_COSE_Recipient_decrypt(pRecip, cbitKey, pbKey, perr)) break;
}
CHECK_CONDITION(pRecip != NULL, COSE_ERR_NO_RECIPIENT_FOUND);
// Build protected headers
cn_cbor * cnProtected = _COSE_arrayget_int(&pcose->m_message, INDEX_PROTECTED);
CHECK_CONDITION((cnProtected != NULL) && (cnProtected->type == CN_CBOR_BYTES), COSE_ERR_INVALID_PARAMETER);
cn_cbor * cnContent = _COSE_arrayget_int(&pcose->m_message, INDEX_BODY);
CHECK_CONDITION((cnContent != NULL) && (cnContent->type == CN_CBOR_BYTES), COSE_ERR_INVALID_PARAMETER);
// Build authenticated data
pbAuthData = NULL;
pAuthData = cn_cbor_array_create(CBOR_CONTEXT_PARAM_COMMA &cbor_error);
CHECK_CONDITION_CBOR(pAuthData != NULL, cbor_error);
ptmp = cn_cbor_string_create("MAC", CBOR_CONTEXT_PARAM_COMMA &cbor_error);
CHECK_CONDITION_CBOR(ptmp != NULL, cbor_error);
CHECK_CONDITION_CBOR(cn_cbor_array_append(pAuthData, ptmp, &cbor_error), cbor_error);
ptmp = cn_cbor_data_create(cnProtected->v.bytes, (int) cnProtected->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
CHECK_CONDITION_CBOR(ptmp != NULL, cbor_error);
CHECK_CONDITION_CBOR(cn_cbor_array_append(pAuthData, ptmp, &cbor_error), cbor_error);
ptmp = cn_cbor_data_create(NULL, 0, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
CHECK_CONDITION_CBOR(ptmp != NULL, cbor_error);
CHECK_CONDITION_CBOR(cn_cbor_array_append(pAuthData, ptmp, &cbor_error), cbor_error);
ptmp = cn_cbor_data_create(cnContent->v.bytes, (int) cnContent->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
CHECK_CONDITION_CBOR(ptmp != NULL, cbor_error);
CHECK_CONDITION_CBOR(cn_cbor_array_append(pAuthData, ptmp, &cbor_error), cbor_error);
cbAuthData = cn_cbor_encoder_write(RgbDontUseMac, 0, sizeof(RgbDontUseMac), pAuthData);
pbAuthData = (byte *)COSE_CALLOC(cbAuthData, 1, context);
CHECK_CONDITION(pbAuthData != NULL, COSE_ERR_OUT_OF_MEMORY);
CHECK_CONDITION((cn_cbor_encoder_write(pbAuthData, 0, cbAuthData+1, pAuthData) == cbAuthData), COSE_ERR_CBOR); // M00HACK
switch (alg) {
case COSE_Algorithm_HMAC_256_256:
if (!HMAC_Validate(pcose, 256, 256, pbKey, cbitKey/8, pbAuthData, cbAuthData, perr)) goto errorReturn;
break;
case COSE_Algorithm_HMAC_256_64:
if (!HMAC_Validate(pcose, 256, 64, pbKey, cbitKey/8, pbAuthData, cbAuthData, perr)) goto errorReturn;
break;
case COSE_Algorithm_HMAC_384_384:
if (!HMAC_Validate(pcose, 384, 384, pbKey, cbitKey/8, pbAuthData, cbAuthData, perr)) goto errorReturn;
break;
case COSE_Algorithm_HMAC_512_512:
if (!HMAC_Validate(pcose, 512, 512, pbKey, cbitKey/8, pbAuthData, cbAuthData, perr)) goto errorReturn;
break;
case COSE_Algorithm_CBC_MAC_128_64:
case COSE_Algorithm_CBC_MAC_256_64:
if (!AES_CBC_MAC_Validate(pcose, 64, pbKey, cbitKey/8, pbAuthData, cbAuthData, perr)) goto errorReturn;
break;
case COSE_Algorithm_CBC_MAC_128_128:
case COSE_Algorithm_CBC_MAC_256_128:
if (!AES_CBC_MAC_Validate(pcose, 128, pbKey, cbitKey/8, pbAuthData, cbAuthData, perr)) goto errorReturn;
break;
default:
FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
break;
}
if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);
if (pAuthData != NULL) cn_cbor_free(pAuthData CBOR_CONTEXT_PARAM);
if ((pbKey != NULL)) {
memset(pbKey, 0xff, cbitKey / 8);
COSE_FREE(pbKey, context);
}
return true;
errorReturn:
if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);
if (pAuthData != NULL) cn_cbor_free(pAuthData CBOR_CONTEXT_PARAM);
if ((pbKey != NULL)) {
memset(pbKey, 0xff, cbitKey / 8);
COSE_FREE(pbKey, context);
}
return false;
}