Fixes for STSAFE-A120 ECDHE

[dgarske]

Description

Fixes for STSAFE-A120 ECDHE

Testing

On Pi5 with STSAFE-A120:

=== Running wolfssl_stsafe_test ===
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wolfSSL STSAFE-A120 Crypto Callback Test Suite
================================================

Initializing STSAFE-A120...
STSAFE-A120 initialized successfully.
STSAFE crypto callback registered (devId: 0x53545341).

Test: RNG with STSAFE-A120
  Random data: 85 59 8D B2 0C EA 44 60 86 98 79 6D B4 8F CE 78 ...
[PASS] RNG with STSAFE-A120

Test: ECC P-256 Key Generation with STSAFE-A120
STSAFE: KeyGen slot 1, curve_id 0
  Public Key X: 6C4DCA5736637C77...
  Public Key Y: B44A20A27C0F7D5A...
[PASS] ECC P-256 key generation

Test: ECC P-384 Key Generation with STSAFE-A120
STSAFE: KeyGen slot 1, curve_id 1
  Public Key X: 229BA85B27643A95...
  Public Key Y: D9E0FDB641DF9224...
[PASS] ECC P-384 key generation

Test: ECDSA P-256 Sign/Verify with STSAFE-A120
STSAFE: KeyGen slot 1, curve_id 0
  Key pair generated.
STSAFE: Sign using slot 1
  Signature (70 bytes): 3044022024DC7E23...
  Signature verified!
  Verifying signature using STSAFE hardware...
  Hardware signature verified!
[PASS] ECDSA P-256 sign/verify

Test: ECDSA P-384 Sign/Verify with STSAFE-A120
STSAFE: KeyGen slot 1, curve_id 1
  Key pair generated.
STSAFE: Sign using slot 1
  Signature (104 bytes): 3066023100A161F0...
  Signature verified!
  Verifying signature using STSAFE hardware...
  Hardware signature verified!
[PASS] ECDSA P-384 sign/verify

Test: ECDHE P-256 Ephemeral Key Generation with STSAFE-A120
  Note: Uses stse_generate_ECDHE_key_pair() for ephemeral keys
STSAFE: KeyGen slot 255, curve_id 0
  Public Key X: B00E019415B256BC...
  Public Key Y: 1ADE13316DBDD227...
  Ephemeral key generated successfully (private key in STSE internal memory)
[PASS] ECDHE P-256 ephemeral key generation

Test: ECDH P-256 Shared Secret Computation (STSAFE + wolfCrypt)
  Note: One side uses STSAFE hardware (ephemeral slot), other uses wolfCrypt software
  Generating hardware key pair (STSAFE ephemeral slot via crypto callback)...
STSAFE: KeyGen slot 255, curve_id 0
    HW key generated (in ephemeral slot)
  Generating software key pair (wolfCrypt)...
    SW key generated
  Computing shared secret (STSAFE: HW priv * SW pub)...
STSAFE: ECDH with slot 255, curve_id 0
    STSAFE shared secret computed (32 bytes)
  Computing shared secret (wolfCrypt: SW priv * HW pub)...
    wolfCrypt shared secret computed (32 bytes)
  Shared secrets match! (20D59859DD3F3836...)
[PASS] ECDH P-256 shared secret computation

================================================
Test Summary: 7 passed, 0 failed
================================================

=== Running wolfssl_stsafe_full_test ===
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wolfSSL STSAFE-A120 Full Integration Test Suite
================================================================

Initializing STSAFE-A120...
STSAFE-A120 initialized successfully.
STSAFE crypto callback registered (devId: 0x53545341).

Test: RNG Benchmark (STSAFE-A120)
  Generated 100 x 256 bytes in 2.90 ms
  Throughput: 8632.60 KB/s
[PASS] RNG benchmark

Test: ECDSA P-256 Benchmark (STSAFE-A120)
STSAFE: KeyGen slot 1, curve_id 0
  Key generation: 49.66 ms
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
STSAFE: Sign using slot 1
  Signing: 10 ops in 512.94 ms (19.50 ops/sec)
  Verification: 10 ops in 788.35 ms (12.68 ops/sec)
[PASS] ECDSA P-256 benchmark

Test: ECDH P-256 Key Exchange (HW + SW)
  Note: STSAFE key (ephemeral slot 0xFF) for one side, software for other
  Generating hardware key pair (STSAFE)...
STSAFE: KeyGen slot 255, curve_id 0
    HW Key generated in 39.50 ms
  Generating software key pair...
    SW Key generated in 10.64 ms
  Computing shared secret (STSAFE: HW priv * SW pub)...
STSAFE: ECDH with slot 255, curve_id 0
    STSAFE ECDH computed in 71.75 ms
  Computing shared secret (Software: SW priv * HW pub)...
    Software ECDH computed in 10.66 ms
  Shared secrets match! (D639079B44D7ADC9...)
[PASS] ECDH P-256 key exchange (HW+SW)

Test: Multiple Sequential Operations
  Generating key pair 1...
STSAFE: KeyGen slot 1, curve_id 0
STSAFE: Sign using slot 1
    Key 1: Generated and signed successfully
  Generating key pair 2...
STSAFE: KeyGen slot 1, curve_id 0
STSAFE: Sign using slot 1
    Key 2: Generated and signed successfully
  Generating key pair 3...
STSAFE: KeyGen slot 1, curve_id 0
STSAFE: Sign using slot 1
    Key 3: Generated and signed successfully
  Verifying all signatures...
    All 3 signatures verified!
[PASS] Multiple sequential operations

================================================================
Test Summary: 4 passed, 0 failed
================================================================

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[dgarske]

Jenkins retest this please: "Generic Config" "AgentOfflineException"