utils: add public API to get EK templates

[whooo]

Useful for when create_ek_template isn't a good fit.

Fixes #684

[whooo]

@salrashid123, would this work interface work for you?

[salrashid123]

thanks for this. works fine but do users have to know the string form of the template directly (eg, is there some sort of const string name for that anywhere eg ek_templates.EK_RSA2048?

from tpm2_pytss import *
from tpm2_pytss.utils import ek_templates, ek_template

ectx = ESAPI(tcti="swtpm:port=2321")
ectx.startup(TPM2_SU.CLEAR)

for k in ek_template.available_templates():
    print(k)

tmpl = ek_templates.get("ek-rsa2048")
#tmpl = ek_templates.get("L-1")

inSensitive = TPM2B_SENSITIVE_CREATE(TPMS_SENSITIVE_CREATE(userAuth=TPM2B_AUTH(''))) 
ek_handle, ek_pub, _, _, _ = ectx.create_primary(inSensitive, tmpl.template, ESYS_TR.ENDORSEMENT)

print(ek_pub.get_name())

ectx.flush_context(ek_handle)
ectx.close()

giving

$ python3 esapi_tpm2.py 
ek-rsa2048
l-1
ek-ecc256
l-2
ek-high-rsa2048
h-1
ek-high-ecc256
h-2
ek-high-ecc384
h-3
ek-high-ecc521
h-4
ek-high-eccsm2p256
h-5
ek-high-rsa3072
h-6
ek-high-rsa4096
h-7
000b7c65ad76d4ee1f1cf2f927ab371f24b295cb42bfb3a18c61cf2c66cbb80f8e50

[whooo]

´ek_templates.keys()´ should return the available templates by name

[salrashid123]

what i was mostly commenting on was having a const somewhere for the name and alias

eg to avoid someone doing this (eg omitting the hypen or having a typo on the .get() call)

tmpl = ek_templates.get("ekrsa2048")

---

also, i'm missing something but i can't seem to iterate using ek_templates.keys()

for k in ek_templates.keys():
    print(k)

TypeError: 'method' object is not iterable

[whooo]

what i was mostly commenting on was having a const somewhere for the name and alias

eg to avoid someone doing this (eg omitting the hypen or having a typo on the .get() call)

tmpl = ek_templates.get("ekrsa2048")

ek_templates["bad_name"] raises a KeyError if the template doesn't exists, you can also do "bad_name" in ek_templates to check if the template exists or not
The get method is mostly there so it behaves as dict or if you want do your own error handling

also, i'm missing something but i can't seem to iterate using ek_templates.keys()

for k in ek_templates.keys():
    print(k)

TypeError: 'method' object is not iterable

Fixed now

[salrashid123]

i can now iterate over the keys fine

for k in ek_templates.keys():
    print(k)

but i'm still missing something here

this supposed to work, correct?

try:
    tmpl = ek_templates["ek-rsa2048"]
except KeyError as e:
    print(e)

$ python3 --version
Python 3.13.12


$ python3 esapi_tpm2.py
    tmpl = ek_templates["ek-rsa2048"]
           ~~~~~~~~~~~~^^^^^^^^^^^^^^
TypeError: type 'ek_templates' is not subscriptable