% tpm2_ecdhzgen(1) tpm2-tools | General Commands Manual

NAME

tpm2_ecdhzgen(1) - Recovers the shared secret value (Z) from a public point and a specified private key.

SYNOPSIS

tpm2_ecdhzgen [OPTIONS]

DESCRIPTION

tpm2_ecdhzgen(1) - Recovers the shared secret value (Z) from a public point and a specified private key. It will perform the multiplication of the provided inPoint (QB) with the private key (ds) and return the coordinates of the resultant point (Z = (xZ , yZ) ≔ [hds]QB; where h is the cofactor of the curve).

OPTIONS

  • -c, --key-context=FILE:

    Context object pointing to ECC key. Either a file or a handle number. See section "Context Object Format".

  • -p, --key-auth=AUTH:

    The authorization value for the ECC key object.

  • -u, --public=FILE:

    Output ECC point Q.

  • -o, --output=FILE

    Specify file path to save the calculated ecdh secret or Z point.

References

algorithm specifiers details the options for specifying cryptographic algorithms ALGORITHM.

common options collection of common options that provide information many users may expect.

common tcti options collection of options used to configure the various known TCTI modules.

EXAMPLES

tpm2_createprimary -C o -c prim.ctx -Q

tpm2_create -C prim.ctx -c key.ctx -u key.pub -r key.priv -G ecc256:ecdh

tpm2_ecdhkeygen -u ecdh.pub -o ecdh.priv -c key.ctx

tpm2_ecdhzgen -u ecdh.pub -o ecdh.dat -c key.ctx

returns

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