int gen_hash(
unsigned char *inbufp,
int bsize,
unsigned char *outbufp,
CRYPT_ALGO_TYPE alg)
{
CRYPT_CONTEXT hashContext;
unsigned char hash[40];
int ansr = -1;
if (alg != CRYPT_ALGO_SHA1 && alg != CRYPT_ALGO_SHA2)
return -1;
memset(hash, 0, 40);
if (cryptInit_wrapper() != CRYPT_OK)
return -1;
if (cryptCreateContext(&hashContext, CRYPT_UNUSED, alg) != CRYPT_OK)
return -1;
cryptEncrypt(hashContext, inbufp, bsize);
cryptEncrypt(hashContext, inbufp, 0);
if (cryptGetAttributeString(
hashContext, CRYPT_CTXINFO_HASHVALUE, hash, &ansr) != CRYPT_OK)
{
return -1;
}
cryptDestroyContext(hashContext);
if (ansr > 0)
memcpy(outbufp, hash, ansr);
return ansr;
}
int main(
int argc,
char **argv)
{
CRYPT_CONTEXT privKeyContext;
CRYPT_KEYSET cryptKeyset;
if (argc < 2)
{
fprintf(stderr, "Usage: Filename\n");
return 1;
}
printf("Making %s\n", argv[1]);
#define CRYPT_CALL(f) \
do \
{ \
if ((f) != CRYPT_OK) \
{ \
fprintf(stderr, "Error calling %s\n", #f); \
exit(EXIT_FAILURE); \
} \
} while (false)
CRYPT_CALL(cryptInit_wrapper());
CRYPT_CALL(cryptCreateContext(&privKeyContext, CRYPT_UNUSED, CRYPT_ALGO_RSA));
CRYPT_CALL(cryptSetAttributeString(privKeyContext, CRYPT_CTXINFO_LABEL, "label", 5));
CRYPT_CALL(cryptSetAttribute(privKeyContext, CRYPT_CTXINFO_KEYSIZE, 1024 / 8));
CRYPT_CALL(cryptGenerateKey(privKeyContext));
CRYPT_CALL(cryptKeysetOpen(&cryptKeyset, CRYPT_UNUSED, CRYPT_KEYSET_FILE,
argv[1], CRYPT_KEYOPT_CREATE));
CRYPT_CALL(cryptAddPrivateKey(cryptKeyset, privKeyContext, "password"));
CRYPT_CALL(cryptKeysetClose(cryptKeyset));
CRYPT_CALL(cryptDestroyContext(privKeyContext));
#undef CRYPT_CALL
return 0;
}
const char *signCMS(
struct CMS *cms,
const char *keyfilename,
bool bad)
{
bool hashContext_initialized = false;
CRYPT_CONTEXT hashContext;
bool sigKeyContext_initialized = false;
CRYPT_CONTEXT sigKeyContext;
CRYPT_KEYSET cryptKeyset;
int signatureLength;
int tbs_lth;
char *msg = (char *)0;
uchar *tbsp;
uchar *signature = NULL;
uchar hash[40];
struct casn *sidp;
struct Attribute *attrp;
struct AttrTableDefined *attrtdp;
struct SignerInfo *sigInfop;
// signer info
// firat clear out any old stuff in signerInfos that may have been put
// there by old code
while (num_items(&cms->content.signedData.signerInfos.self) > 0)
eject_casn(&cms->content.signedData.signerInfos.self, 0);
sigInfop =
(struct SignerInfo *)
inject_casn(&(cms->content.signedData.signerInfos.self), 0);
// write the signature version (3) to the signer info
write_casn_num(&sigInfop->version.self, 3);
// find the SID
if ((sidp = findSID(cms)) == NULL)
return "finding SID";
// copy the CMS's SID over to the signature's SID
copy_casn(&sigInfop->sid.subjectKeyIdentifier, sidp);
// use sha256 as the algorithm
write_objid(&sigInfop->digestAlgorithm.algorithm, id_sha256);
// no parameters to sha256
write_casn(&sigInfop->digestAlgorithm.parameters.sha256, (uchar *) "", 0);
// first attribute: content type
attrp = (struct Attribute *)inject_casn(&sigInfop->signedAttrs.self, 0);
write_objid(&attrp->attrType, id_contentTypeAttr);
attrtdp =
(struct AttrTableDefined *)inject_casn(&attrp->attrValues.self, 0);
copy_casn(&attrtdp->contentType,
&cms->content.signedData.encapContentInfo.eContentType);
// second attribute: message digest
attrp = (struct Attribute *)inject_casn(&sigInfop->signedAttrs.self, 1);
write_objid(&attrp->attrType, id_messageDigestAttr);
// create the hash for the content
// first pull out the content
if ((tbs_lth =
readvsize_casn(&cms->content.signedData.encapContentInfo.eContent.
self, &tbsp)) < 0)
return "getting content";
// set up the context, initialize crypt
memset(hash, 0, 40);
if (cryptInit_wrapper() != CRYPT_OK)
return "initializing cryptlib";
// the following calls function f, and if f doesn't return 0 sets
// msg to m, then breaks out of the loop. Used immediately below.
#define CALL(f,m) if (f != 0) { msg = m; break; }
// use a "do { ... } while (0)" loop to bracket this code, so we can
// bail out on failure. (Note that this construct isn't really a
// loop; it's a way to use break as a more clean version of goto.)
do
{
// first sign the body of the message
// create the context
CALL(cryptCreateContext(&hashContext, CRYPT_UNUSED, CRYPT_ALGO_SHA2),
"creating context");
hashContext_initialized = true;
// generate the hash
CALL(cryptEncrypt(hashContext, tbsp, tbs_lth), "hashing");
CALL(cryptEncrypt(hashContext, tbsp, 0), "hashing");
// get the hash value. then we're done, so destroy it
CALL(cryptGetAttributeString
(hashContext, CRYPT_CTXINFO_HASHVALUE, hash, &signatureLength),
"getting first hash");
CALL(cryptDestroyContext(hashContext),
"destroying intermediate context");
// insert the hash as the first attribute
attrtdp =
(struct AttrTableDefined *)inject_casn(&attrp->attrValues.self, 0);
write_casn(&attrtdp->messageDigest, hash, signatureLength);
// create signing time attribute; mark the signing time as now
if (getenv("RPKI_NO_SIGNING_TIME") == NULL)
{
attrp =
(struct Attribute *)inject_casn(&sigInfop->signedAttrs.self, 2);
write_objid(&attrp->attrType, id_signingTimeAttr);
attrtdp =
(struct AttrTableDefined *)inject_casn(&attrp->attrValues.self, 0);
write_casn_time(&attrtdp->signingTime.utcTime, time((time_t *) 0));
}
// we are all done with the content
free(tbsp);
// now sign the attributes
// get the size of signed attributes and allocate space for them
if ((tbs_lth = size_casn(&sigInfop->signedAttrs.self)) < 0)
{
msg = "sizing SignerInfo";
break;
}
tbsp = (uchar *) calloc(1, tbs_lth);
encode_casn(&sigInfop->signedAttrs.self, tbsp);
*tbsp = ASN_SET;
// create a new, fresh hash context for hashing the attrs, and hash
// them
CALL(cryptCreateContext(&hashContext, CRYPT_UNUSED, CRYPT_ALGO_SHA2),
"creating hash context");
CALL(cryptEncrypt(hashContext, tbsp, tbs_lth), "hashing attrs");
CALL(cryptEncrypt(hashContext, tbsp, 0), "hashing attrs");
// get the hash value
CALL(cryptGetAttributeString
(hashContext, CRYPT_CTXINFO_HASHVALUE, hash, &signatureLength),
"getting attr hash");
// get the key and sign it
CALL(cryptKeysetOpen
(&cryptKeyset, CRYPT_UNUSED, CRYPT_KEYSET_FILE, keyfilename,
CRYPT_KEYOPT_READONLY), "opening key set");
CALL(cryptCreateContext(&sigKeyContext, CRYPT_UNUSED, CRYPT_ALGO_RSA),
"creating RSA context");
sigKeyContext_initialized = true;
CALL(cryptGetPrivateKey
(cryptKeyset, &sigKeyContext, CRYPT_KEYID_NAME, "label",
"password"), "getting key");
CALL(cryptCreateSignature
(NULL, 0, &signatureLength, sigKeyContext, hashContext),
"signing");
// check the signature to make sure it's right
signature = (uchar *) calloc(1, signatureLength + 20);
// second parameter is signatureMaxLength, so we allow a little more
CALL(cryptCreateSignature
(signature, signatureLength + 20, &signatureLength, sigKeyContext,
hashContext), "signing");
// verify that the signature is right
CALL(cryptCheckSignature
(signature, signatureLength, sigKeyContext, hashContext),
"verifying");
// end of protected block
} while (0);
// done with cryptlib, shut it down
if (hashContext_initialized)
{
cryptDestroyContext(hashContext);
hashContext_initialized = false;
}
if (sigKeyContext_initialized)
{
cryptDestroyContext(sigKeyContext);
sigKeyContext_initialized = false;
}
// did we have any trouble above? if so, bail
if (msg != 0)
{
return msg;
}
// ok, write the signature back to the object
struct SignerInfo sigInfo;
SignerInfo(&sigInfo, (ushort) 0);
decode_casn(&sigInfo.self, signature);
// were we supposed to make a bad signature? if so, make it bad
if (bad)
{
uchar *sig;
int siz = readvsize_casn(&sigInfo.signature, &sig);
sig[0]++;
write_casn(&sigInfo.signature, sig, siz);
free(sig);
}
// copy the signature into the object
copy_casn(&sigInfop->signature, &sigInfo.signature);
delete_casn(&sigInfo.self);
// all done with it now
free(signature);
// Mark it as encrypted with rsa, no params.
// See http://www.ietf.org/mail-archive/web/sidr/current/msg04813.html for
// why we use id_rsadsi_rsaEncryption instead of id_sha_256WithRSAEncryption
// here.
write_objid(&sigInfop->signatureAlgorithm.algorithm,
id_rsadsi_rsaEncryption);
write_casn(&sigInfop->signatureAlgorithm.parameters.self, (uchar *) "", 0);
// no errors, we return NULL
return NULL;
}