Windows: use separate assembly files for RDRAND and RDSEED in order to fix a mysterious crash when MASM_RDSEED_GenerateBlock is called after MASM_RDRAND_GenerateBlock.

src/Crypto/rdrand_ml.asm

@@ -1,9 +1,9 @@
 ;; rdrand.asm - written and placed in public domain by Jeffrey Walton and Uri Blumenthal.
 ;;              Copyright assigned to the Crypto++ project.
 
-;; This ASM file provides RDRAND and RDSEED to downlevel Microsoft tool chains.
-;; Everything "just works" under Visual Studio. Other platforms will have to
-;; run MASM/MASM-64 and then link to the object files.
+;; This ASM file provides RDRAND to downlevel Microsoft tool chains.
+;; Everything "just works" under Visual Studio. Other platforms will
+;; have to run MASM/MASM-64 and then link to the object files.
 
 ;; set ASFLAGS=/nologo /D_M_X86 /W3 /Cx /Zi /safeseh
 ;; set ASFLAGS64=/nologo /D_M_X64 /W3 /Cx /Zi
@@ -13,11 +13,10 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-TITLE    MASM_RDRAND_GenerateBlock and MASM_RDSEED_GenerateBlock
-SUBTITLE Microsoft specific ASM code to utilize RDRAND and RDSEED for down level Microsoft toolchains
+TITLE    MASM_RDRAND_GenerateBlock source file
+SUBTITLE Microsoft specific ASM code to utilize RDRAND for down level Microsoft toolchains
 
 PUBLIC MASM_RDRAND_GenerateBlock
-PUBLIC MASM_RDSEED_GenerateBlock
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -38,7 +37,6 @@ IFDEF _M_X86    ;; Set via the command line
 
 ;; Fastcall calling conventions exports
 ALIAS <@MASM_RDRAND_GenerateBlock@8> = <MASM_RDRAND_GenerateBlock>
-ALIAS <@MASM_RDSEED_GenerateBlock@8> = <MASM_RDSEED_GenerateBlock>
 
 ENDIF
 
@@ -63,13 +61,13 @@ MASM_RDRAND_GenerateBlock PROC   ;; arg1:DWORD, arg2:DWORD
     bsize  EQU edx
 
             ;; Top of While loop
-GenerateBlock_Top:
+RDRAND_GenerateBlock_Top:
 
             ;; Check remaining size
     cmp     bsize, 0
-    je      GenerateBlock_Return
+    je      RDRAND_GenerateBlock_Return
 
-Call_RDRAND_EAX:
+RDRAND_Call_EAX:
             ;; RDRAND is not available prior to VS2012. Just emit
             ;;   the byte codes using DB. This is `rdrand eax`.
     DB      0Fh, 0C7h, 0F0h
@@ -78,46 +76,48 @@ Call_RDRAND_EAX:
             ;; If CF=0, a random number was not available.
 
             ;; Retry immediately
-    jnc     Call_RDRAND_EAX
+    jnc     RDRAND_Call_EAX
 
 RDRAND_succeeded:
 
     cmp     bsize, MWSIZE
-    jb      Partial_Machine_Word
+    jb      RDRAND_Partial_Machine_Word
 
-Full_Machine_Word:
+RDRAND_Full_Machine_Word:
 
     mov     DWORD PTR [buffer], eax
     add     buffer, MWSIZE        ;; No need for Intel Core 2 slow workarounds, like
     sub     bsize, MWSIZE         ;;   `lea buffer,[buffer+MWSIZE]` for faster adds
 
             ;; Continue
-    jmp     GenerateBlock_Top
+    jmp     RDRAND_GenerateBlock_Top
 
             ;; 1,2,3 bytes remain
-Partial_Machine_Word:
+RDRAND_Partial_Machine_Word:
 
             ;; Test bit 1 to see if size is at least 2
     test    bsize, 2
-    jz      Bit_1_Not_Set
+    jz      RDRAND_Bit_1_Not_Set
 
     mov     WORD PTR [buffer], ax
     shr     eax, 16
     add     buffer, 2
 
-Bit_1_Not_Set:
+RDRAND_Bit_1_Not_Set:
 
             ;; Test bit 0 to see if size is at least 1
     test    bsize, 1
-    jz      Bit_0_Not_Set
+    jz      RDRAND_Bit_0_Not_Set
 
     mov     BYTE PTR [buffer], al
+    ;; shr     ax, 8
+    ;; add     buffer, 1
 
-Bit_0_Not_Set:
+RDRAND_Bit_0_Not_Set:
 
             ;; We've hit all the bits
 
-GenerateBlock_Return:
+RDRAND_GenerateBlock_Return:
 
             ;; Clear artifacts
     xor     eax, eax
@@ -127,9 +127,6 @@ MASM_RDRAND_GenerateBlock ENDP
 
 ENDIF    ;; _M_X86
 
-OPTION PROLOGUE:PrologueDef
-OPTION EPILOGUE:EpilogueDef
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
@@ -151,13 +148,13 @@ MASM_RDRAND_GenerateBlock PROC   ;; arg1:QWORD, arg2:QWORD
     bsize  EQU rdx
 
             ;; Top of While loop
-GenerateBlock_Top:
+RDRAND_GenerateBlock_Top:
 
             ;; Check remaining size
     cmp     bsize, 0
-    je      GenerateBlock_Return
+    je      RDRAND_GenerateBlock_Return
 
-Call_RDRAND_RAX:
+RDRAND_Call_RAX:
             ;; RDRAND is not available prior to VS2012. Just emit
             ;;   the byte codes using DB. This is `rdrand rax`.
     DB      048h, 0Fh, 0C7h, 0F0h
@@ -166,254 +163,67 @@ Call_RDRAND_RAX:
             ;; If CF=0, a random number was not available.
 
             ;; Retry immediately
-    jnc     Call_RDRAND_RAX
+    jnc     RDRAND_Call_RAX
 
 RDRAND_succeeded:
 
     cmp     bsize, MWSIZE
-    jb      Partial_Machine_Word
+    jb      RDRAND_Partial_Machine_Word
 
-Full_Machine_Word:
+RDRAND_Full_Machine_Word:
 
     mov     QWORD PTR [buffer], rax
     add     buffer, MWSIZE
     sub     bsize, MWSIZE
 
             ;; Continue
-    jmp     GenerateBlock_Top
+    jmp     RDRAND_GenerateBlock_Top
 
             ;; 1,2,3,4,5,6,7 bytes remain
-Partial_Machine_Word:
+RDRAND_Partial_Machine_Word:
 
             ;; Test bit 2 to see if size is at least 4
     test    bsize, 4
-    jz      Bit_2_Not_Set
+    jz      RDRAND_Bit_2_Not_Set
 
     mov     DWORD PTR [buffer], eax
     shr     rax, 32
     add     buffer, 4
 
-Bit_2_Not_Set:
+RDRAND_Bit_2_Not_Set:
 
             ;; Test bit 1 to see if size is at least 2
     test    bsize, 2
-    jz      Bit_1_Not_Set
+    jz      RDRAND_Bit_1_Not_Set
 
     mov     WORD PTR [buffer], ax
     shr     eax, 16
     add     buffer, 2
 
-Bit_1_Not_Set:
+RDRAND_Bit_1_Not_Set:
 
             ;; Test bit 0 to see if size is at least 1
     test    bsize, 1
-    jz      Bit_0_Not_Set
+    jz      RDRAND_Bit_0_Not_Set
 
     mov     BYTE PTR [buffer], al
+    ;; shr     ax, 8
+    ;; add     buffer, 1
 
-Bit_0_Not_Set:
+RDRAND_Bit_0_Not_Set:
 
             ;; We've hit all the bits
 
-GenerateBlock_Return:
-
-            ;; Clear artifacts
-    xor     rax, rax
-	ret
-
-MASM_RDRAND_GenerateBlock ENDP
-
-ENDIF    ;; _M_X64
-
-OPTION PROLOGUE:PrologueDef
-OPTION EPILOGUE:EpilogueDef
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-IFDEF _M_X86    ;; Set via the command line
-
-.CODE
-ALIGN   8
-OPTION PROLOGUE:NONE
-OPTION EPILOGUE:NONE
-
-;; No need for Load_Arguments due to fastcall
-;;   ECX (in): arg1, byte* buffer
-;;   EDX (in): arg2, size_t bsize
-
-MASM_RDSEED_GenerateBlock PROC   ;; arg1:DWORD, arg2:DWORD
-
-    MWSIZE EQU 04h    ;; machine word size
-    buffer EQU ecx
-    bsize  EQU edx
-
-            ;; Top of While loop
-GenerateBlock_Top:
-
-            ;; Check remaining size
-    cmp     bsize, 0
-    je      GenerateBlock_Return
-
-Call_RDSEED_EAX:
-            ;; RDSEED is not available prior to VS2012. Just emit
-            ;;   the byte codes using DB. This is `rdseed eax`.
-    DB      0Fh, 0C7h, 0F8h
-
-            ;; If CF=1, the number returned by RDSEED is valid.
-            ;; If CF=0, a random number was not available.
-
-            ;; Retry immediately
-    jnc     Call_RDSEED_EAX
-
-RDSEED_succeeded:
-
-    cmp     bsize, MWSIZE
-    jb      Partial_Machine_Word
-
-Full_Machine_Word:
-
-    mov     DWORD PTR [buffer], eax
-    add     buffer, MWSIZE        ;; No need for Intel Core 2 slow workarounds, like
-    sub     bsize, MWSIZE         ;;   `lea buffer,[buffer+MWSIZE]` for faster adds
-
-            ;; Continue
-    jmp     GenerateBlock_Top
-
-            ;; 1,2,3 bytes remain
-Partial_Machine_Word:
-
-            ;; Test bit 1 to see if size is at least 2
-    test    bsize, 2
-    jz      Bit_1_Not_Set
-
-    mov     WORD PTR [buffer], ax
-    shr     eax, 16
-    add     buffer, 2
-
-Bit_1_Not_Set:
-
-            ;; Test bit 0 to see if size is at least 1
-    test    bsize, 1
-    jz      Bit_0_Not_Set
-
-    mov     BYTE PTR [buffer], al
-
-Bit_0_Not_Set:
-
-            ;; We've hit all the bits
-
-GenerateBlock_Return:
-
-            ;; Clear artifacts
-    xor     eax, eax
-	ret
-
-MASM_RDSEED_GenerateBlock ENDP
-
-ENDIF    ;; _M_X86
-
-OPTION PROLOGUE:PrologueDef
-OPTION EPILOGUE:EpilogueDef
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-IFDEF _M_X64    ;; Set via the command line
-
-.CODE
-ALIGN   16
-OPTION PROLOGUE:NONE
-OPTION EPILOGUE:NONE
-
-;; No need for Load_Arguments due to fastcall
-;;   RCX (in): arg1, byte* buffer
-;;   RDX (in): arg2, size_t bsize
-
-MASM_RDSEED_GenerateBlock PROC   ;; arg1:QWORD, arg2:QWORD
-
-    MWSIZE EQU 08h    ;; machine word size
-    buffer EQU rcx
-    bsize  EQU rdx
-
-            ;; Top of While loop
-GenerateBlock_Top:
-
-            ;; Check remaining size
-    cmp     bsize, 0
-    je      GenerateBlock_Return
-
-Call_RDSEED_RAX:
-            ;; RDSEED is not available prior to VS2012. Just emit
-            ;;   the byte codes using DB. This is `rdseed rax`.
-    DB      048h, 0Fh, 0C7h, 0F8h
-
-            ;; If CF=1, the number returned by RDSEED is valid.
-            ;; If CF=0, a random number was not available.
-
-            ;; Retry immediately
-    jnc     Call_RDSEED_RAX
-
-RDSEED_succeeded:
-
-    cmp     bsize, MWSIZE
-    jb      Partial_Machine_Word
-
-Full_Machine_Word:
-
-    mov     QWORD PTR [buffer], rax
-    add     buffer, MWSIZE
-    sub     bsize, MWSIZE
-
-            ;; Continue
-    jmp     GenerateBlock_Top
-
-            ;; 1,2,3,4,5,6,7 bytes remain
-Partial_Machine_Word:
-
-            ;; Test bit 2 to see if size is at least 4
-    test    bsize, 4
-    jz      Bit_2_Not_Set
-
-    mov     DWORD PTR [buffer], eax
-    shr     rax, 32
-    add     buffer, 4
-
-Bit_2_Not_Set:
-
-            ;; Test bit 1 to see if size is at least 2
-    test    bsize, 2
-    jz      Bit_1_Not_Set
-
-    mov     WORD PTR [buffer], ax
-    shr     eax, 16
-    add     buffer, 2
-
-Bit_1_Not_Set:
-
-            ;; Test bit 0 to see if size is at least 1
-    test    bsize, 1
-    jz      Bit_0_Not_Set
-
-    mov     BYTE PTR [buffer], al
-
-Bit_0_Not_Set:
-
-            ;; We've hit all the bits
-
-GenerateBlock_Return:
+RDRAND_GenerateBlock_Return:
 
             ;; Clear artifacts
     xor     rax, rax
     ret
 
-MASM_RDSEED_GenerateBlock ENDP
+MASM_RDRAND_GenerateBlock ENDP
 
 ENDIF    ;; _M_X64
 
-OPTION PROLOGUE:PrologueDef
-OPTION EPILOGUE:EpilogueDef
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;