STMicroelectronics UM2542 STM32MPx Series Key Generator Software User Manual

: September 14, 2024
: STMicroelectronics

Table of Contents

UM2542 STM32MPx Series Key Generator Software
Product Information
Specifications
Product Usage Instructions
1. Install STM32MP-KeyGen
2. STM32MP-KeyGen Command Line Interface
3. Examples
- FAQ
Q: How many key pairs can be generated at once?
Q: What encryption algorithms are supported?
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)

UM2542 STM32MPx Series Key Generator Software

Product Information

Specifications

Product Name: STM32MPx series key generator software
Version: UM2542 – Rev 3
Release Date: June 2024
Manufacturer: STMicroelectronics

Product Usage Instructions

1. Install STM32MP-KeyGen

To install the STM32MP-KeyGen software, follow the installation
instructions provided in the user manual.

2. STM32MP-KeyGen Command Line Interface

The STM32MP-KeyGen software can be used from the command line
interface. Below are the available commands:

–private-key (-prvk)
–public-key (-pubk)
–public-key-hash (-hash)
–absolute-path (-abs)
–password (-pwd)
–prvkey-enc (-pe)
–ecc-algo (-ecc)
–help (-h and -?)
–version (-v)
–number-key (-n)

3. Examples

Here are some examples of how to use STM32MP-KeyGen:

```
* Example 1: -abs /home/user/KeyFolder/ -pwd azerty
```
- Example 2: -abs /home/user/KeyFolder/ -pwd azerty -pe
  aes128

FAQ

Q: How many key pairs can be generated at once?

A: You can generate up to eight key pairs simultaneously by
providing eight passwords.

Q: What encryption algorithms are supported?

A: The software supports aes256 and aes128 encryption
algorithms.

UM2542
User manual
STM32MPx series key generator software description
Introduction
The STM32MPx series key generator software (named STM32MP-KeyGen in this document) is integrated in the STM32CubeProgrammer (STM32CubeProg). STM32MP- KeyGen is a tool that generates the ECC keys pair needed for signing binary images. The generated keys are used by the STM32 Signing tool for signing process. STM32MP-KeyGen generates a public key file, a private key file and a hash public key file. The public key file contains the generated ECC public key in PEM format. The private key file contains the encrypted ECC private key in PEM format. The encryption can be done using the aes 128 cbc or aes 256 cbc ciphers. The cipher selection is done using the –prvkey-enc option. The hash public key file contains the SHA-256 hash of the public key in binary format. The SHA-256 hash is calculated based on the public key without any encoding format. The first byte of the public key is present just to indicate whether the public key is in compressed or uncompressed format. Since only uncompressed format is supported, this byte is removed.

DT51280V1

UM2542 – Rev 3 – June 2024 For further information contact your local STMicroelectronics sales office.

www.st.com

1
Note:

UM2542
Install STM32MP-KeyGen
Install STM32MP-KeyGen
This tool is installed with the STM32CubeProgrammer package (STM32CubeProg). For more information about the set-up procedure, refer to the section 1.2 of the user manual STM32CubeProgrammer software description (UM2237). This software applies to the STM32MPx series Arm®-based MPUs. Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.

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UM2542
STM32MP-KeyGen command line interface

2

STM32MP-KeyGen command line interface

The following sections describe how to use STM32MP-KeyGen from command line.

2.1

Commands

The available commands are listed below:

·

–private-key (-prvk)

Description: private key file path (.pem extension)

Syntax: -prvk

Example: -prvk ../privateKey.pem

·

–public-key (-pubk)

Description: Public key file path (.pem extension)

Syntax: -pubk

Example: -pubk C:publicKey.pem

·

–public-key-hash (-hash)

Description: Hash image file path (.bin extension)

Syntax: -hash

·

–absolute-path (-abs)

Description: Absolute path for output files

Syntax: -abs

Example: -abs C:KeyFolder

·

–password (-pwd)

Description: Password of the private key (this password must contain at least four characters)

Example: -pwd azerty

Note:

Include eight passwords to generate eight keypairs.

Syntax 1:-pwd

Syntax 2: -pwd

·

–prvkey-enc (-pe)

Description: Encrypting private key algorithm (aes128/aes256) (aes256 algorithm is the default algorithm)

Syntax: -pe aes128

·

–ecc-algo (-ecc)

Description: ECC algorithm for keys generation (prime256v1/brainpoolP256t1) (prime256v1 is the default algorithm)

Syntax: -ecc prime256v1

·

–help (-h and -?)

Description: Shows help.

·

–version (-v)

Description: Displays the tool version.

·

–number-key (-n)

Description: Generate number of key pairs {1 or 8} with Hash of table file

Syntax: -n

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UM2542
STM32MP-KeyGen command line interface

2.2

Examples

The following examples show how to use STM32MP-KeyGen:

·

Example 1

-abs /home/user/KeyFolder/ -pwd azerty

All files (publicKey.pem, privateKey.pem and publicKeyhash.bin) are created in the /home/user/KeyFolder/ folder. The private key is encrypted with the aes256 default algorithm.

·

Example 2

-abs /home/user/keyFolder/ -pwd azerty pe aes128

All files (publicKey.pem, privateKey.pem and publicKeyhash.bin) are created in the /home/user/KeyFolder/ folder. The private key is encrypted with the aes128 algorithm.

·

Example 3

-pubk /home/user/public.pem prvk /home/user/Folder1/Folder2/private.pem hash /home/user/pubKeyHash.bin pwd azerty

Even if the Folder1 and Folder2 does not exist, they are created.

·

Example 4

Generate eight key pairs in the working directory:

./STM32MP_KeyGen_CLI.exe -abs . -pwd abc1 abc2 abc3 abc4 abc5 abc6 abc7 abc8 -n 8

The output gives the following files: eight public key files: publicKey0x{0..7}.pem eight private key files: privateKey0x{0..7}.pem eight public key hash files: publicKeyHash0x{0..7}.bin one file of PKTH: publicKeysHashHashes.bin

·

Example 5

Generate one key pair in the working directory:

./STM32MP_KeyGen_CLI.exe -abs . -pwd abc1 -n 1

The output gives the following files: one public key file: publicKey.pem one private key file: privateKey.pem one public key hash file: publicKeyHash.bin one file of PKTH: publicKeysHashHashes.bin

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UM2542
STM32MP-KeyGen command line interface

2.3

Standalone mode

When executing STM32MP-KeyGen in Standalone mode, an absolute path and a password are requested as shown in the figure below.

Figure 1. STM32MP-KeyGen in Standalone mode

When the user press , the files are generated in the

folder. Then enter the password twice and select one of the two algorithms (prime256v1 or brainpoolP256t1) by pressing the respective key (1 or 2). Finally select an encrypting algorithm (aes256 or aes128) by pressing the respective key (1 or 2).

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Revision history
Date 14-Feb-2019 24-Nov-2021
26-Jun-2024

Table 1. Document revision history

Version 1 2
3

Changes
Initial release.
Updated: · Section 2.1: Commands · Section 2.2: Examples
Replaced in the whole document: · STM32MP1 series by STM32MPx series · STM32MP1-KeyGen by STM32MP-KeyGen

UM2542

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UM2542
Contents
Contents
1 Install STM32MP-KeyGen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 2 STM32MP- KeyGen command line interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1 Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.3 Standalone mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

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UM2542
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