add documentation for sm3sum command. Signed-off-by: Heiko Schocher <[email protected]> ---
doc/usage/cmd/sm3sum.rst | 117 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 doc/usage/cmd/sm3sum.rst diff --git a/doc/usage/cmd/sm3sum.rst b/doc/usage/cmd/sm3sum.rst new file mode 100644 index 00000000000..3b157779a0e --- /dev/null +++ b/doc/usage/cmd/sm3sum.rst @@ -0,0 +1,117 @@ +.. SPDX-License-Identifier: GPL-2.0+: + Copyright 2025 Nabladev + Written by Heiko Schocher <[email protected]> + +.. index:: + single: sm3sum (command) + +sm3sum command +============== + +Synopsis +-------- + +:: + + sm3sum - compute SM3 message digest + + Usage: + sm3sum address count [[*]sum] + - compute SM3 message digest [save to sum] + sm3sum -v address count [*]sum + - verify sm3sum of memory area + + +Description +----------- + +The sm3sum command calculates the SM3_256 Hash from a +address with length of count bytes. If the -v option is +passed to the command, it compares the calculated hash +with the hash found at address sum. + +The SM3 secure hash, is calculated as specified by OSCCA GM/T +0004-2012 SM3 and described at + +https://datatracker.ietf.org/doc/html/draft-sca-cfrg-sm3-02 + +Parameters +---------- + +address + address from where the sm3 hash is calculated + +count + length in bytes of memory area for which the sm3 hash is calculated + +sum + address of hash to which the calculated hash gets stored + + or if "-v" option is passed: + + address of hash with which the calculated hash gets compared. + +Example +------- + +create some data + +:: + + u-boot=> mw 0x0000000100000000 0x426f6f46 1 + u-boot=> md.b 0x0000000100000000 4 + 00000000: 46 6f 6f 42 FooB + +and calculate the sm3sum from address and store it in environment +variable hashval + +:: + + u-boot=> sm3sum 0x0000000100000000 4 hashval + sm3_256 for 100000000 ... 100000003 ==> cdf49da4e33017bf2d9fe87b885d80c9a7c920be7e10ffb8c89036a1eb1503b7 + u-boot=> print hashval + hashval=cdf49da4e33017bf2d9fe87b885d80c9a7c920be7e10ffb8c89036a1eb1503b7 + u-boot=> + +or calculate sm3sum from address and store it at address sum + +:: + + u-boot=> sm3sum 0x0000000100000000 4 *0x0000000110000000 + sm3_256 for 100000000 ... 100000003 ==> cdf49da4e33017bf2d9fe87b885d80c9a7c920be7e10ffb8c89036a1eb1503b7 + +and now check if this hash is a valid sm3sum with "-v" option + +:: + + u-boot=> sm3sum -v 0x0000000100000000 4 *0x0000000110000000 + u-boot=> echo $? + 0 + +example with wrong hash + +:: + + u-boot=> sm3sum -v 0x0000000100000000 4 *0x0000000110000004 + sm3_256 for 100000000 ... 100000003 ==> cdf49da4e33017bf2d9fe87b885d80c9a7c920be7e10ffb8c89036a1eb1503b7 != e33017bf2d9fe87b885d80c9a7c920be7e10ffb8c89036a1eb1503b7ffffffff ** ERROR ** + u-boot=> + + +Configuration +------------- + +Enable the sm3sum command via Kconfig option CONFIG_CMD_SM3SUM. +The "-v" option is separate enabled through Kconfig option +CONFIG_SM3SUM_VERIFY. + + +Return value +------------ + +The return value $? is true (0) if the hash is calculated or if +the created hash is the same as the hash stored in memory at +address sum. + +The return value is false (1) if there is a problem with +calculating the hash, or if the hash is not the same as +the hash stored ar address sum. -- 2.20.1
