Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 1 | // This file was extracted from the TCG Published |
| 2 | // Trusted Platform Module Library |
| 3 | // Part 3: Commands |
| 4 | // Family "2.0" |
| 5 | // Level 00 Revision 01.16 |
| 6 | // October 30, 2014 |
| 7 | |
| 8 | #include "InternalRoutines.h" |
| 9 | #include "ECDH_KeyGen_fp.h" |
| 10 | #ifdef TPM_ALG_ECC |
| 11 | // |
| 12 | // |
| 13 | // Error Returns Meaning |
| 14 | // |
Scott | aad1406 | 2016-10-11 10:42:52 -0700 | [diff] [blame] | 15 | // TPM_RC_ATTRIBUTES If the key is restricted or the key is not a decryption key |
Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 16 | // TPM_RC_KEY keyHandle does not reference a non-restricted decryption ECC key |
| 17 | // |
| 18 | TPM_RC |
| 19 | TPM2_ECDH_KeyGen( |
| 20 | ECDH_KeyGen_In *in, // IN: input parameter list |
| 21 | ECDH_KeyGen_Out *out // OUT: output parameter list |
| 22 | ) |
| 23 | { |
| 24 | OBJECT *eccKey; |
| 25 | TPM2B_ECC_PARAMETER sensitive; |
| 26 | TPM_RC result; |
| 27 | |
| 28 | // Input Validation |
| 29 | |
| 30 | eccKey = ObjectGet(in->keyHandle); |
| 31 | |
| 32 | // Input key must be a non-restricted, decrypt ECC key |
| 33 | if( eccKey->publicArea.type != TPM_ALG_ECC) |
Vadim Bendebury | 065e0d7 | 2015-10-16 09:35:42 -0700 | [diff] [blame] | 34 | return TPM_RC_KEY + RC_ECDH_KeyGen_keyHandle; |
Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 35 | |
| 36 | if( eccKey->publicArea.objectAttributes.restricted == SET |
| 37 | || eccKey->publicArea.objectAttributes.decrypt != SET |
| 38 | ) |
Scott | aad1406 | 2016-10-11 10:42:52 -0700 | [diff] [blame] | 39 | return TPM_RC_ATTRIBUTES + RC_ECDH_KeyGen_keyHandle; |
Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 40 | |
| 41 | // Command Output |
| 42 | do |
| 43 | { |
| 44 | // Create ephemeral ECC key |
| 45 | CryptNewEccKey(eccKey->publicArea.parameters.eccDetail.curveID, |
| 46 | &out->pubPoint.t.point, &sensitive); |
| 47 | |
| 48 | out->pubPoint.t.size = TPMS_ECC_POINT_Marshal(&out->pubPoint.t.point, |
| 49 | NULL, NULL); |
| 50 | |
| 51 | // Compute Z |
| 52 | result = CryptEccPointMultiply(&out->zPoint.t.point, |
| 53 | eccKey->publicArea.parameters.eccDetail.curveID, |
| 54 | &sensitive, &eccKey->publicArea.unique.ecc); |
| 55 | // The point in the key is not on the curve. Indicate that the key is bad. |
| 56 | if(result == TPM_RC_ECC_POINT) |
| 57 | return TPM_RC_KEY + RC_ECDH_KeyGen_keyHandle; |
| 58 | // The other possible error is TPM_RC_NO_RESULT indicating that the |
| 59 | // multiplication resulted in the point at infinity, so get a new |
| 60 | // random key and start over (hardly ever happens). |
| 61 | } |
| 62 | while(result == TPM_RC_NO_RESULT); |
| 63 | |
| 64 | if(result == TPM_RC_SUCCESS) |
| 65 | // Marshal the values to generate the point. |
| 66 | out->zPoint.t.size = TPMS_ECC_POINT_Marshal(&out->zPoint.t.point, |
| 67 | NULL, NULL); |
| 68 | |
| 69 | return result; |
| 70 | } |
| 71 | #endif |