Our device is based on nRF52840 with SDK 15.0.0
The device communicates over BLE with PC application (aka client) via "uart" service.
PC (client) messages are signed using ECDSA with secp265r1 curve and the device verifies the signature of received messages before processing them.
PC side ECDSA implementation is based on Org.BouncyCastle.Asn1.Sec package for C#.
Device side ECDSA implementation is almost identical to ecdsa example (Bob's verification).
Verification alway failed on execution backend implementation with error code 34070 - invalid signature despite I used private and public keys from ecdsa example.
Any ideas?
Moreover I ran ecdsa example from SDK on Nordic's DK PCA10056 and just put alice sign and bob verification in a loop.
Each cycle (see below output) I got different signature but bob's verification pass.
Is that makes sense?
<info> app: ECDSA example started.
<info> app: Alice's signature generation
<info> app: Alice's message hash:
42BA8354DB263A6A5A9F74D6B7CEB4C962A3D8FD58A41969E521EB0222455415
<info> app: Alice's signature:
000F05AD9269E25050B05BB4754C480C66A515650C63863C12A4D6634F04580490DCE86B7CED05C526202A412A7F4D7CD586F768B5FBA0592EAF56A63E7C0320
<info> app: Bob's message verification
<info> app: Signature is valid. Message is authentic.
<info> app: Alice's signature generation
<info> app: Alice's message hash:
42BA8354DB263A6A5A9F74D6B7CEB4C962A3D8FD58A41969E521EB0222455415
<info> app: Alice's signature:
EECEF1BF8D3CFA84EB748DE4990B14B832BD383ADB4C9B2D5C51AEA7DF0E91DD13B39228BE460A5D6163514B8C7F63A8FF476D9E062BD0E7A50F87DE00AA5BAB
<info> app: Bob's message verification
<info> app: Signature is valid. Message is authentic.
<info> app: Alice's signature generation
<info> app: Alice's message hash:
42BA8354DB263A6A5A9F74D6B7CEB4C962A3D8FD58A41969E521EB0222455415
<info> app: Alice's signature:
D423EDD1F6ABA0B6213380DA51794A6B724D7F3DFC351AD881DFDD4B86B8348EEAFEC7E0CFCFCA3C64C774E03470A96573E4358FDC873B7F7CDE086241DF89D6
<info> app: Bob's message verification
<info> app: Signature is valid. Message is authentic.
<info> app: Alice's signature generation
<info> app: Alice's message hash:
42BA8354DB263A6A5A9F74D6B7CEB4C962A3D8FD58A41969E521EB0222455415
<info> app: Alice's signature:
8AF1749C0B605995C7F18E30A68D78D43AD41431174683AF8CDDD89C2105441EB5D00A215FDDF5ACB6AC0D8C465271716819D594F78B5976B3B74759463AED93
<info> app: Bob's message verification
<info> app: Signature is valid. Message is authentic.
<info> app: Alice's signature generation
<info> app: Alice's message hash:
42BA8354DB263A6A5A9F74D6B7CEB4C962A3D8FD58A41969E521EB0222455415
<info> app: Alice's signature:
03A29A6A08F02E8282AD210CA44253B1D15C66E8194FA27F4EB45D3F6171C65CBB8A7311D1A9CC436F13EBFA7AC3BED3C1C3C365682AEBF2138A28065761A42B
<info> app: Bob's message verification
<info> app: Signature is valid. Message is authentic.
<info> app: ECDSA example executed successfully.
