X-CUBE-CRYPTOLIB cmox_eddsa_sign HardFault

[lll]

stm32L476VC + CubeMX + IAR + X-CUBE-CRYPTOLIB STM32CubeExpansion_Crypto_V4.2.0

i copy the example from "NUCLEO-L476RG\Applications\ECC\EDDSA_SignVerify" to my project, cmox_eddsa_sign will cause HardFault:

The processor has escalated a configurable-priority exception to HardFault.

A precise data access error has occurred (CFSR.PRECISERR, BFAR)

At data address 0x58024c00.

An imprecise data access error has occurred (CFSR.IMPRECISERR, BFAR)

At data address 0x58024c00.

Exception occurred at PC = 0x800901e, LR = 0x20002cc4

call stack:

HardFault_Handler()
<Exception frame>
[cmox_md_generateTag + 0x51]

other api work well (cmox_rsa_pkcs1v15_verify, cmox_ecdsa_sign ...)

[Tesla DeLorean]

It's like you've bound the wrong library.

This is the CRC Peripheral address for the STM32H7, that's going to fail on the STM32L4 series

@Jocelyn RICARD @STTwo-32 

https://community.st.com/t5/stm32-mcus-security/x-cube-cryptolib-how-is-the-crc-peripheral-base-address-set/td-p/584072

[Tesla DeLorean]

Use libSTM32Cryptographic_CM4.a, not libSTM32Cryptographic_CM7.a ??

Or if there's a variable in the initialization / context passing in CRC_BASE address

CM3

    cmox_md_generateTag
        0x00000000:    e92d4ffc    -..O    PUSH     {r2-r11,lr}
        0x00000004:    4602        .F      MOV      r2,r0
        0x00000006:    b085        ..      SUB      sp,sp,#0x14
        0x00000008:    68d0        .h      LDR      r0,[r2,#0xc]
        0x0000000a:    6913        .i      LDR      r3,[r2,#0x10]
        0x0000000c:    f8dfc16c    ..l.    LDR      r12,[pc,#364] ; [cmox_table = 0x17c] = 0
        0x00000010:    f8df816c    ..l.    LDR      r8,[pc,#364] ; [0x180] = 0
        0x00000014:    eba00a03    ....    SUB      r10,r0,r3
        0x00000018:    6850        Ph      LDR      r0,[r2,#4]
        0x0000001a:    f0400004    @...    ORR      r0,r0,#4
        0x0000001e:    6050        P`      STR      r0,[r2,#4]
        0x00000020:    2700        .'      MOVS     r7,#0
        0x00000022:    a803        ..      ADD      r0,sp,#0xc
        0x00000024:    9002        ..      STR      r0,[sp,#8]
        0x00000026:    f10d0e0c    ....    ADD      lr,sp,#0xc
        0x0000002a:    e9d83400    ...4    LDRD     r3,r4,[r8,#0]
        0x0000002e:    a803        ..      ADD      r0,sp,#0xc
        0x00000030:    4d54        TM      LDR      r5,[pc,#336] ; [cmox_init_ctxi = 0x184] = 0
        0x00000032:    e9c03400    ...4    STRD     r3,r4,[r0,#0]
        0x00000036:    7828        (x      LDRB     r0,[r5,#0]
        0x00000038:    4d53        SM      LDR      r5,[pc,#332] ; [0x188] = 0x9310c55f
        0x0000003a:    2800        .(      CMP      r0,#0
        0x0000003c:    bf0c        ..      ITE      EQ
        0x0000003e:    2300        .#      MOVEQ    r3,#0
        0x00000040:    2304        .#      MOVNE    r3,#4
        0x00000042:    4699        .F      MOV      r9,r3
        0x00000044:    f85c3003    \..0    LDR      r3,[r12,r3]
        0x00000048:    f85e4009    ^..@    LDR      r4,[lr,r9]
        0x0000004c:    4423        #D      ADD      r3,r3,r4
        0x0000004e:    2601        .&      MOVS     r6,#1
        0x00000050:    601d        .`      STR      r5,[r3,#0]
        0x00000052:    681c        .h      LDR      r4,[r3,#0]
        0x00000054:    609e        .`      STR      r6,[r3,#8]
        0x00000056:    f8dc3004    ...0    LDR      r3,[r12,#4]
        0x0000005a:    9d03        ..      LDR      r5,[sp,#0xc]
        0x0000005c:    f8dc9000    ....    LDR      r9,[r12,#0]
        0x00000060:    f8de6004    ...`    LDR      r6,[lr,#4]
        0x00000064:    405d        ]@      EORS     r5,r5,r3
        0x00000066:    4065        e@      EORS     r5,r5,r4
        0x00000068:    4c48        HL      LDR      r4,[pc,#288] ; [0x18c] = 0x12008504
        0x0000006a:    4065        e@      EORS     r5,r5,r4
        0x0000006c:    ea890606    ....    EOR      r6,r9,r6
        0x00000070:    4c47        GL      LDR      r4,[pc,#284] ; [0x190] = 0x7a0168fc
        0x00000072:    4066        f@      EORS     r6,r6,r4
        0x00000074:    1975        u.      ADDS     r5,r6,r5
        0x00000076:    4c47        GL      LDR      r4,[pc,#284] ; [0x194] = 0xff24f5c0
        0x00000078:    4065        e@      EORS     r5,r5,r4
...

CM7

    cmox_md_generateTag
        0x00000000:    e92d4ffc    -..O    PUSH     {r2-r11,lr}
        0x00000004:    b085        ..      SUB      sp,sp,#0x14
        0x00000006:    4602        .F      MOV      r2,r0
        0x00000008:    68d0        .h      LDR      r0,[r2,#0xc]
        0x0000000a:    6913        .i      LDR      r3,[r2,#0x10]
        0x0000000c:    2700        .'      MOVS     r7,#0
        0x0000000e:    f8dfc178    ..x.    LDR      r12,[pc,#376] ; [cmox_table = 0x188] = 0
        0x00000012:    f10d0e0c    ....    ADD      lr,sp,#0xc
        0x00000016:    f8df8174    ..t.    LDR      r8,[pc,#372] ; [0x18c] = 0
        0x0000001a:    eba00903    ....    SUB      r9,r0,r3
        0x0000001e:    6853        Sh      LDR      r3,[r2,#4]
        0x00000020:    a803        ..      ADD      r0,sp,#0xc
        0x00000022:    f0430304    C...    ORR      r3,r3,#4
        0x00000026:    6053        S`      STR      r3,[r2,#4]
        0x00000028:    9002        ..      STR      r0,[sp,#8]
        0x0000002a:    a803        ..      ADD      r0,sp,#0xc
        0x0000002c:    4d58        XM      LDR      r5,[pc,#352] ; [cmox_init_ctxi = 0x190] = 0
        0x0000002e:    e9d83400    ...4    LDRD     r3,r4,[r8,#0]
        0x00000032:    e9c03400    ...4    STRD     r3,r4,[r0,#0]
        0x00000036:    7828        (x      LDRB     r0,[r5,#0]
        0x00000038:    4d56        VM      LDR      r5,[pc,#344] ; [0x194] = 0x9310c55f
        0x0000003a:    f8dfb15c    ..\.    LDR      r11,[pc,#348] ; [0x198] = 0x7a0168fc
        0x0000003e:    2800        .(      CMP      r0,#0
        0x00000040:    bf0c        ..      ITE      EQ
        0x00000042:    2300        .#      MOVEQ    r3,#0
        0x00000044:    2304        .#      MOVNE    r3,#4
        0x00000046:    461c        .F      MOV      r4,r3
        0x00000048:    f85c3003    \..0    LDR      r3,[r12,r3]
        0x0000004c:    f85e4004    ^..@    LDR      r4,[lr,r4]
        0x00000050:    18e3        ..      ADDS     r3,r4,r3
        0x00000052:    2401        .$      MOVS     r4,#1
        0x00000054:    601d        .`      STR      r5,[r3,#0]
        0x00000056:    681e        .h      LDR      r6,[r3,#0]
        0x00000058:    609c        .`      STR      r4,[r3,#8]
        0x0000005a:    f8dc3004    ...0    LDR      r3,[r12,#4]
        0x0000005e:    9d03        ..      LDR      r5,[sp,#0xc]
        0x00000060:    f8dc4000    ...@    LDR      r4,[r12,#0]
        0x00000064:    405d        ]@      EORS     r5,r5,r3
        0x00000066:    4075        u@      EORS     r5,r5,r6
        0x00000068:    4e4c        LN      LDR      r6,[pc,#304] ; [0x19c] = 0x12008504
        0x0000006a:    4075        u@      EORS     r5,r5,r6
        0x0000006c:    f8de6004    ...`    LDR      r6,[lr,#4]
        0x00000070:    4066        f@      EORS     r6,r6,r4
        0x00000072:    ea8b0606    ....    EOR      r6,r11,r6
        0x00000076:    4435        5D      ADD      r5,r5,r6
        0x00000078:    4e49        IN      LDR      r6,[pc,#292] ; [0x1a0] = 0xff24f5c0
        0x0000007a:    4075        u@      EORS     r5,r5,r6
        0x0000007c:    2800        .(      CMP      r0,#0
...

[lll]

i use libSTM32Cryptographic_CM4.a, and active crc in CubeMX, maybe there is something wrong in the lib

   0x800'9052: 0x9a09         LDR       R2, [SP, #0x24]
   0x800'9054: 0xa901         ADD       R1, SP, #0x4
   0x800'9056: 0x4648         MOV       R0, R9
   0x800'9058: 0xf7f9 0xffbe  BL        cmox_membuf_free        ; 0x800'2fd8
   0x800'905c: 0x9804         LDR       R0, [SP, #0x10]
   0x800'905e: 0xb00b         ADD       SP, SP, #0x2c
   0x800'9060: 0xe8bd 0x8ff0  POP.W     {R4-R11, PC}
                 cmox_md_generateTag:
   0x800'9064: 0xe92d 0x4ffc  PUSH.W    {R2-R11, LR}
   0x800'9068: 0x4602         MOV       R2, R0
   0x800'906a: 0xb085         SUB       SP, SP, #0x14
   0x800'906c: 0x68d0         LDR       R0, [R2, #0xc]
   0x800'906e: 0x6913         LDR       R3, [R2, #0x10]
   0x800'9070: 0xf8df 0xc16c  LDR.W     R12, [PC, #0x16c]       ; cmox_table
   0x800'9074: 0xf8df 0x816c  LDR.W     R8, [PC, #0x16c]        ; 0x800'9d04
   0x800'9076: 0x816c         STRH      R4, [R5, #0xa]
   0x800'9078: 0xeba0 0x0a03  SUB.W     R10, R0, R3
   0x800'907c: 0x6850         LDR       R0, [R2, #0x4]
   0x800'907e: 0xf040 0x0004  ORR.W     R0, R0, #4
   0x800'9082: 0x6050         STR       R0, [R2, #0x4]
   0x800'9084: 0x2700         MOVS      R7, #0
   0x800'9086: 0xa803         ADD       R0, SP, #0xc
   0x800'9088: 0x9002         STR       R0, [SP, #0x8]
   0x800'908a: 0xf10d 0x0e0c  ADD.W     LR, SP, #12             ; 0xc
   0x800'908e: 0xe9d8 0x3400  LDRD      R3, R4, [R8]
   0x800'9092: 0xa803         ADD       R0, SP, #0xc
   0x800'9094: 0x4d54         LDR.N     R5, [PC, #0x150]        ; cmox_init_ctxi
   0x800'9096: 0xe9c0 0x3400  STRD      R3, R4, [R0]
   0x800'909a: 0x7828         LDRB      R0, [R5]
   0x800'909c: 0x4d53         LDR.N     R5, [PC, #0x14c]        ; 0x9310'c55f
   0x800'909e: 0x2800         CMP       R0, #0
   0x800'90a0: 0xbf0c         ITE       EQ
   0x800'90a2: 0x2300         MOVEQ     R3, #0
   0x800'90a4: 0x2304         MOVNE     R3, #4
   0x800'90a6: 0x4699         MOV       R9, R3
   0x800'90a8: 0xf85c 0x3003  LDR.W     R3, [R12, R3]
   0x800'90ac: 0xf85e 0x4009  LDR.W     R4, [LR, R9]
   0x800'90b0: 0x4423         ADD       R3, R3, R4
   0x800'90b2: 0x2601         MOVS      R6, #1
   0x800'90b4: 0x601d         STR       R5, [R3]
   0x800'90b6: 0x681c         LDR       R4, [R3]
   0x800'90b8: 0x609e         STR       R6, [R3, #0x8]
   0x800'90ba: 0xf8dc 0x3004  LDR.W     R3, [R12, #0x4]
   0x800'90be: 0x9d03         LDR       R5, [SP, #0xc]
   0x800'90c0: 0xf8dc 0x9000  LDR.W     R9, [R12]
   0x800'90c4: 0xf8de 0x6004  LDR.W     R6, [LR, #0x4]
   0x800'90c8: 0x405d         EORS      R5, R5, R3
   0x800'90ca: 0x4065         EORS      R5, R5, R4
   0x800'90cc: 0x4c48         LDR.N     R4, [PC, #0x120]        ; 0x1200'8504
   0x800'90ce: 0x4065         EORS      R5, R5, R4
   0x800'90d0: 0xea89 0x0606  EOR.W     R6, R9, R6
   0x800'90d4: 0x4c47         LDR.N     R4, [PC, #0x11c]        ; 0x7a01'68fc
   0x800'90d6: 0x4066         EORS      R6, R6, R4
   0x800'90d8: 0x1975         ADDS      R5, R6, R5
   0x800'90da: 0x4c47         LDR.N     R4, [PC, #0x11c]        ; 0xff24'f5c0

[Dor_RH]

Hello @lll,

We'll check it and get back to you.

Thanks for your contribution.

Dor_RH

[Jocelyn RICARD]

Hello @lll ,

you are using CM4 library, so no issue here.

Pointing on this specific address (0x58024c00) that is actual CRC address of the STM32H7 exactly at the place where you should have STM32L4 address, may be related to your project setup. I don't know how though :)

Could you please check your project usage of cmsis files ? This address must have been introduced somewhere.

Also, if you can share your project I could have a look.

Best regards

Jocelyn

[Tesla DeLorean]

How does the library make a determination of the CRC peripheral address? Seen multiple reports of this issue, so a root-cause needs to be determined.

This seems like an internal thing. A thing that ST's doing, purposely, and at some point becomes a liability.

How does Hard Faulting play into Operational Safety?

@STOne-32 

[Tesla DeLorean]

>>This address must have been introduced somewhere

It's coming from the library, it's being used to muddle / obfuscate initialization constants, keys, etc. as part of a strategy to limit the libraries to STM32 cores.

[lll]

thanks

[Jocelyn RICARD · Accepted solution]

Hello @lll ,

I could reproduce a crash but it was located in the internal crypto allocator.

In your code you forgot to increase the stack size. Setting stack size to 0x600 in the icf file should solve your issue.

Best regards

Jocelyn