On Tue, 2018-10-02 at 19:58 +0100, David Woodhouse wrote:
> 
> So... that now *is* working for signing. However, while the
> corresponding 'rsautl -verify' works fine with James's tpm2 engine, it
> fails with tpm2tss:
> 
> $ openssl rsautl -verify -engine tpm2tss -inkey ../openssl_tpm2_engine/tpm2-engine.tss -keyform engine -in testsig.tpm2tss
> Initializing
> engine "tpm2tss" set.
> Loading private key ../openssl_tpm2_engine/tpm2-engine.tss
> get_auth called for object user key with ui_method 0x55ced253fdc0
> Enter password for user key:
> password is 
> Loaded key uses alg-id 1
> Creating RSA key object.
> Created RSA key object.
> TPM2 Key loaded
> RSA operation error
> 140407559393728:error:0407006A:rsa routines:RSA_padding_check_PKCS1_type_1:block type is not 01:../crypto/rsa/rsa_pk1.c:75:
> 140407559393728:error:04067072:rsa routines:rsa_ossl_public_decrypt:padding check failed:../crypto/rsa/rsa_ossl.c:586:
> 
> 
> So... is it the public key that I've misconverted somehow?

I've resolved that one too. James explicitly sets the exponent in 
tpm2Data->pub.publicArea.parameters.rsaDetail.exponent to zero if it's
0x10001, with a comment saying "zero means standard exponent. Some TPM
chips will reject a non standard exponent".

So now I do have OpenConnect using my wrapped VPN key, with both
engines (although tpm2-tss-engine stills asks me for an empty
password).

By setting objectAttributes when creating a key, I can make
tpm2tss-genkey work again too.

Full patch below, for reference. Don't heckle too hard; it exists
mostly to document the current incompatibilities. I'll let the two of
you come to an agreement on the correct way to resolve them, while I
throw together some GnuTLS code to use the same PEM files.

(Since the tpm2-tss-engine code is under a licence which lets me crib
from it, and the libraries actually have pkgconfig etc., I suppose
that's made this application author's implementation choice fairly much
a no-brainer...)




--- a/src/tpm2-tss-engine-common.h
+++ b/src/tpm2-tss-engine-common.h
@@ -55,8 +55,7 @@ TSS2_RC init_tpm_key(ESYS_CONTEXT **ctx, ESYS_TR *keyHandle,
         .objectAttributes = (TPMA_OBJECT_USERWITHAUTH | \
                              TPMA_OBJECT_RESTRICTED | \
                              TPMA_OBJECT_DECRYPT | \
-                             TPMA_OBJECT_FIXEDTPM | \
-                             TPMA_OBJECT_FIXEDPARENT | \
+                             TPMA_OBJECT_NODA | \
                              TPMA_OBJECT_SENSITIVEDATAORIGIN), \
         .authPolicy = { \
              .size = 0, \
--- a/src/tpm2-tss-engine-rsa.c
+++ b/src/tpm2-tss-engine-rsa.c
@@ -304,7 +304,7 @@ populate_rsa(RSA *rsa) {
         ERR(populate_rsa, ERR_R_MALLOC_FAILURE);
         goto error;
     }
-    BN_set_word(rsa->e, tpm2Data->pub.publicArea.parameters.rsaDetail.exponent);
+    BN_set_word(rsa->e, tpm2Data->pub.publicArea.parameters.rsaDetail.exponent ? : 0x10001);
 
     /* Setting private portions to 0 values so the public key can be extracted
        from the keyfile if this is desired. */
@@ -366,7 +366,7 @@ populate_rsa(RSA *rsa) {
         goto error;
     }
 
-    BN_set_word(e, tpm2Data->pub.publicArea.parameters.rsaDetail.exponent);
+    BN_set_word(e, tpm2Data->pub.publicArea.parameters.rsaDetail.exponent ? : 0x10001);
     BN_set_word(d, 0);
     BN_set_word(p, 0);
     BN_set_word(q, 0);
@@ -485,6 +485,8 @@ tpm2tss_rsa_genkey(RSA *rsa, int bits, BIGNUM *e, char *password)
     if (e)
         inPublic.publicArea.parameters.rsaDetail.exponent = BN_get_word(e);
 
+    inPublic.publicArea.objectAttributes = TPMA_OBJECT_SENSITIVEDATAORIGIN | TPMA_OBJECT_NODA;
+
     if (password) {
         DBG("Setting a password for the created key.\n");
         if (strlen(password) > sizeof(tpm2Data->userauth.buffer) - 1) {