Datasheet

PUKCL_ZpEcDsaVerify(nu1ScalarNumber) = <Base of the ScalarNumber>;
PUKCL_ZpEcDsaVerify(nu1OrderPointBase) = <Base of the order of A point>;
PUKCL_ZpEcDsaVerify(nu1ABase) = <Base of the a parameter of the curve>;
PUKCL_ZpEcDsaVerify(nu1Workspace) = <Base of the workspace>;
PUKCL_ZpEcDsaVerify(nu1HashBase) = <Base of the SHA resulting hash>;
PUKCL_ZpEcDsaVerify(u2ScalarLength) = < Length of ScalarNumber>;
...
// vPUKCL_Process() is a macro command, which populates the service name
// and then calls the library...
vPUKCL_Process(ZpEcDsaVerifyFast, pvPUKCLParam);
if (PUKCL(u2Status) == PUKCL_OK)
{
...
}ou
else
if(PUKCL(u2Status) == PUKCL_WRONG_SIGNATURE)
{
...
}
else // Manage the error
43.3.6.12.6 Constraints
No overlapping between either input and output are allowed. The following conditions must be avoided to
ensure that the service works correctly:
• nu1ModBase, nu1CnsBase, nu1PointABase, nu1PointPublicKeyGen, nu1PointSignature,
nu1OrderPointBase,nu1ABase, nu1Workspace or nu1HashBase are not aligned on 32-bit
boundaries
• {nu1ModBase, u2ModLength + 4}, {nu1CnsBase, u2ModLength + 8}, {nu1PointABase,
3*u2ModLength+ 12}, {nu1PointPublicKeyGen, 3*u2ModLength + 12}, {nu1PointSignature,
2*u2ScalarLength + 8}, {nu1OrderPointBase, u2ScalarLength + 4}, {nu1ABase, u2ModLength + 4},
{nu1Workspace, <WorkspaceLength>} or {nu1HashBase, u2ScalarLength + 4} are not in Crypto
RAM
• u2ModLength is either: < 12, > 0xffc or not a 32-bit length
• All overlapping between {nu1ModBase, u2ModLength + 4}, {nu1CnsBase, u2ModLength +8},
{nu1PointABase, 3*u2ModLength + 12}, {nu1PointPublicKeyGen, 3*u2ModLength + 12},
{nu1PointSignature, 2*u2ScalarLength + 8}, {nu1OrderPointBase, u2ScalarLength + 4}, {nu1ABase,
u2ModLength + 4}, {nu1Workspace, <WorkspaceLength>} and {nu1HashBase, u2ScalarLength + 4}
43.3.6.12.7 Status Returned Values
Table 43-88. ZpEcDsaVerifyFast Service Return Codes
Returned Status Importance Meaning
PUKCL_OK – The computation passed without problem. The signature
is the good one.
PUKCL_WRONG_SIGNATURE Warning The signature is wrong.
43.3.6.13 Quick Verifying an ECDSA Signature (Compliant with FIPS 186-2)
43.3.6.13.1 Purpose
This service is used to verify an ECDSA signature following the FIPS 186-2. It performs the second step
of the Signature Verification using Quick Dual Multiplying to perform computation.
A hash value (HashVal) must be provided as input, it has to be previously computed from the message
whose signature is verified using a secure hash algorithm.
As second significant input, the Signature is provided to be checked.
SAM D5x/E5x Family Data Sheet
Public Key Cryptography Controller (PUKCC)
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1537