NAME

TPMLIB_GetInfo - Get Information about the TPM implementation

LIBRARY

TPM library (libtpms, -ltpms)

SYNOPSIS

#include <libtpms/tpm_library.h>

char *TPMLIB_GetInfo(TPMLIB_InfoFlags flags);

DESCRIPTION

The TPMLIB_GetInfo() function allows to query for TPM implementation specifics and get a JSON string in return. Which data is to be returned can be specified in the flags parameter that may be a logical 'or' concatenation of flags. If passed flags are not supported, nothing is returned . If a 0 is passed in, an empty JSON Object '{}' is returned.

The following flags are defined and return JSON objects as shown:

TPMLIB_INFO_TPMSPECIFICATION

{"TPMSpecification":{"family":"1.2","level":2,"revision":116}}

TPMLIB_INFO_TPMATTRIBUTES

{"TPMAttributes":{"manufacturer":"id:00001014","version":"id:00740001","model":"swtpm"}}

TPMLIB_INFO_TPMFEATURES (since v0.8.0)

{"TPMFeatures":{"RSAKeySizes":[1024,2048,3072]}}

This JSON object may be extended in the future.

TPMLIB_INFO_RUNTIME_ALGORITHMS (since v0.10.0)

 {
   "RuntimeAlgorithms": {
     "Implemented": "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-nist-p192," \
                    "ecc-nist-p224,ecc-nist-p256,ecc-nist-p384," \
                    "ecc-nist-p521,"ecc-bn-p256,ecc-bn-p638,ecc-sm2-p256," \
                    "symcipher,camellia,camellia-min-size=128,cmac,ctr,ofb," \
                    "cbc,cfb,ecb",
     "CanBeDisabled": "tdes,sha1,sha512,rsassa,rsaes,rsapss,ecmqv,ecc-nist," \
                      "ecc-bn,ecc-nist-p192,ecc-nist-p224,ecc-nist-p521," \
                      "ecc-bn-p256,ecc-bn-p638,ecc-sm2-p256,camellia,cmac," \
                      "ctr,ofb,cbc,ecb",
     "Enabled": "rsa,rsa-min-size=1024,hmac,aes,aes-min-size=128,mgf1," \
                "keyedhash,xor,sha256,sha384,null,oaep,ecdsa,ecdh,ecdaa," \
                "sm2,ecschnorr,kdf1-sp800-56a,kdf2,kdf1-sp800-108,ecc," \
                "ecc-min-size=192,ecc-bn,ecc-nist-p192,ecc-nist-p224," \
                "ecc-nist-p256,ecc-nist-p384,ecc-nist-p521,ecc-bn-p256," \
                "ecc-bn-p638,ecc-sm2-p256,symcipher,camellia," \
                "camellia-min-size=128,cmac,ctr,ofb,cbc,cfb,ecb",
     "Disabled": "tdes,sha1,sha512,rsassa,rsaes,rsapss,ecmqv,ecc-nist"
   }
 }
    

This JSON object enumerates all implemented algorithms as well as supported elliptic curve cryptography (ECC) curves. Those verbs enumerated under CanBeDisabled represent algorithms and ECC curves that a user may omit from a profile, thus making them unavailable to applications. The verbs enumerated under Enabled and Disabled represent algorithms that are enabled and disabled in the currently active profile.

The verbs ecc-nist and ecc-bn are shortcuts enabling all currently implemented ECC NIST curves (ecc-nist-p192, ecc-nist-p256, ...) and BN (Baretto-Naehrig) curves (ecc-bn-p256, ecc-bn-p638). If omitted then the individual curves can still be enumerated individually to enable them. Since ecc-nist-p256 and ecc-nist-p384 cannot be disabled, they must be enumerated if the ecc-nist shortcut is not used.

Minimum key sizes for rsa, ecc, tdes, aes, and camellia are also described.

When new algorithms and ECC curves are added to the TPM in the future, then this JSON object will return more algorithms.

TPMLIB_INFO_RUNTIME_COMMANDS (since v0.10.0)

{
"RuntimeCommands": {
"Implemented": "0x11f-0x122,0x124-0x12e,0x130-0x140,0x142-0x159," \
"0x15b-0x15e,0x160-0x165,0x167-0x174,0x176-0x178," \
"0x17a-0x193,0x197,0x199-0x19a",
"CanBeDisabled": "0x11f,0x121-0x122,0x124-0x128,0x12a-0x12e,0x130," \
"0x132-0x13b,0x13d-0x140,0x142,0x146-0x147,0x149-0x14d," \
"0x14f-0x152,0x154-0x155,0x159,0x15b,0x15d-0x15e," \
"0x160-0x164,0x167-0x168,0x16a-0x172,0x174,0x177-0x178," \
"0x17b,0x17f-0x181,0x183-0x184,0x187-0x193,0x197," \
0x199-0x19a",
"Enabled": "0x11f-0x122,0x124-0x12e,0x130-0x140,0x142-0x159,0x15b-0x15e," \
"0x160-0x165,0x167-0x174,0x176-0x178,0x17a-0x193,0x197," \
"0x199-0x19a",
"Disabled": ""
} }

This JSON object enumerates all implemented commands by their hexadecimal numbers and shows which ones can be disabled, which ones are currently enabled and which ones are disabled.

TPMLIB_INFO_ACTIVE_PROFILE (since v0.10.0)

This JSON object shows the currently active profile.

 {
   "ActiveProfile": {
     "Name": "null",
     "StateFormatLevel": 1,
     "Commands": "0x11f-0x122,0x124-0x12e,0x130-0x140,0x142-0x159," \
                 "0x15b-0x15e,0x160-0x165,0x167-0x174,0x176-0x178," \
                 "0x17a-0x193,0x197",
     "Algorithms": "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,symcipher,camellia," \
                   "camellia-min-size=128,cmac,ctr,ofb,cbc,cfb,ecb",
     "Description": "The profile enables the commands and algorithms that " \
                    "were enabled in libtpms v0.9. This profile is " \
                    "automatically used when the state does not have a " \
                    "profile, for example when it was created by " \
                    "libtpms v0.9 or before."
   }
 }
    

The above profile is the 'null' profile. If the null profile is used then the state will again be readable by libtpms v0.9.

TPMLIB_INFO_AVAILABLE_PROFILES (since v0.10.0)

This JSON object enumerates available profiles.

 {
   "AvailableProfiles": [
     {
       "Name": "default-v1",
       "StateFormatLevel": 4,
       "Commands": "0x11f-0x122,0x124-0x12e,0x130-0x140,0x142-0x159,...",
       "Algorithms": "rsa,rsa-min-size=1024,tdes,tdes-min-size=128,...",
       "Description": "This profile enables all currently supported ...",
     },
     {
       "Name": "null",
       "StateFormatLevel": 1,
       "Commands": "0x11f-0x122,0x124-0x12e,0x130-0x140,0x142-0x159,...",
       "Algorithms": "rsa,rsa-min-size=1024,tdes,tdes-min-size=128,...",
       "Description": "The profile enables the commands and algorithms ...",
     },
     ....
   ]
 }
    

Future versions of libtpms may enumerate other profiles.

RETURN VALUE

This function returns a JSON string on success and a NULL pointer if a memory allocation failure occurred.

The caller must free() the returned string.

SEE ALSO