Some algorithms are missing in VM comparing to host vm-swtpm.log

[yanqzhan]

Hi @stefanberger,
Continuing the discussion#133, when I check 'tpm2_getcap algorithms' in VM, I found "min-size, null, ecc-nis,ecc-bn,ecc-sm2-p256," are missing. Do you know the reason please? Seems all ecc* are removed except ecc, but I saw two kdf1_* there.
Another question: is 'null' meanful in vm-swtpm.log? what is it used for?
Thank you!
For example:
In VM：

#  tpm2_getcap algorithms|grep -v "  "| tr '\n' ','
rsa:,tdes:,sha1:,hmac:,aes:,mgf1:,keyedhash:,xor:,sha256:,sha384:,sha512:,rsassa:,rsaes:,rsapss:,oaep:,ecdsa:,ecdh:,ecdaa:,sm2:,ecschnorr:,ecmqv:,kdf1_sp800_56a:,kdf2:,kdf1_sp800_108:,ecc:,symcipher:,camellia:,cmac:,ctr:,ofb:,cbc:,cfb:,ecb:,

In host vm-swtpm.log:
"rsa,rsa-min-size=1024,tdes,tdes-min-size=128,sha1,hmac,aes,aes-min-size=128,mgf1,keyedhash,xor,sha256,sha384,sha512,null,rsassa,rsaes,rsapss,oaep,ecdsa,ecdh,ecdaa,sm2,ecschnorr,ecmqv,kdf1-sp800-56a,kdf2,kdf1-sp800-108,ecc,ecc-min-size=192,ecc-nist,ecc-bn,ecc-sm2-p256,symcipher,camellia,camellia-min-size=128,cmac,ctr,ofb,cbc,cfb,ecb"

[stefanberger]

Continuing the discussion#133, when I check 'tpm2_getcap algorithms' in VM, I found "min-size, null, ecc-nis,ecc-bn,ecc-sm2-p256," are missing. Do you know the reason please?

ecc-nist and ecc-bn are shortcuts to enable all NIST and BN elliptic curve algorithms respectively. With ecc-min-size you can select the minimum size of the keys that are supposed to be enabled within these shortcuts. They are basically alternatives to enumerating all algorithms individually. Therefore, these are not verbs describing TPM 2 algorithms.

null is a verb describing an official TPM 2 algorithm. It is listed in profiles for completeness reasons.

ecc-sm2-p256 is a similar description for sm2-p256 as is ecc-nist-p192/256/384/... for nist-p192/256/384/... curve. I prefixed all ecc algorithms with ecc.

[yanqzhan]

Get it. Thank you!
I'm closing this discussion.