bq34z100-G1: SHA-1/HMAC Authentication

The authentication engine should work the same for the bq34z100-G1. Could you provide a key, challenge and the Gauge Digest and I can check them to see whether I see the same?

Hi Thomas

Below are some examples, the 'Local digest' is what I am generating, the 'bq34z100 digest' is what I am reading back from the gauge after sending the message.

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From the bq26100 datasheet example:
Key: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Message: c8 2c a3 ca 10 de c7 26 8e 07 0a 7c f0 d1 fe 82 20 aa d3 b8

Local digest: fb 8a 34 24 58 e0 b1 36 98 8c b5 20 3b b2 3f 94 df d4 44 0e
bq34z100 digest: d9 d6 58 dd 3f 8c c0 92 ff f5 9b a4 f4 b6 e4 df 9f f8 a2 d0

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With the default key:
Key: 01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
Message: c8 2c a3 ca 10 de c7 26 8e 07 0a 7c f0 d1 fe 82 20 aa d3 b8

Local digest: b4 6f 60 21 95 5e 20 3e e1 05 a2 23 5a e7 a0 ac c1 ff 0a ed
bq34z100 digest: a8 9f 35 e7 16 3a 1f 0d 4f 8d ee fe 10 2d a4 91 5e a5 e4 c3

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With a zeroed message:
Key: 01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
Message: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Local digest: 2f a2 7c eb 5b 61 64 84 62 0f e3 22 17 c2 9b 0a 8e 3c f3 f0
bq34z100 digest: f0 f3 3c 8e 0a 9b c2 17 22 e3 0f 62 84 64 61 5b eb 7c a2 2f

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And both zeroed:
Key: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Message: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Local digest: 86 8d 54 93 eb ad 51 f1 28 e3 14 aa 40 55 f5 ef 54 c6 26 69
bq34z100 digest: 48 f7 c4 b3 5c 91 29 7a 95 92 ed 86 04 ed 45 6d ae 77 cf 86
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I have access via bqStudio if that can provide any further useful diagnostics for you.

Many thanks for your time, regards
Ian

Ian,

The Message has to be written to the device in reverse byte order. e.g.

for:

c82ca3ca10dec7268e070a7cf0d1fe8220aad3b8

enter:

b8d3aa2082fed1f07c0a078e26c7de10caa32cc8

The Digest will be returned in reverse byte order as well.

I modified the bqz to add an Authentication tool to the bqStudio platform. This should help with the experiments.You can place it into this directory.

C:\ti\BatteryManagementStudio\config

Tom

5873.0100_0_16-bq34z100G1.bqz

Hi Thomas

Thanks for that, I had overlooked the byte order, and the symmetric default and example keys masked it.

The authentication tool is very useful and has allowed me to try some more live data. I've found using an all-0 key does appear to elicit an incorrect gauge digest, while, say, 10000000000000000000000000000000 gets the correct response. I wonder if you can reproduce this?

So, apart from this I'm good,  thanks again,

Ian