diff options
Diffstat (limited to 'src/Crypto/rdseed_ml.asm')
| -rw-r--r-- | src/Crypto/rdseed_ml.asm | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/src/Crypto/rdseed_ml.asm b/src/Crypto/rdseed_ml.asm new file mode 100644 index 00000000..60704230 --- /dev/null +++ b/src/Crypto/rdseed_ml.asm @@ -0,0 +1,230 @@ +;; rdrand.asm - written and placed in public domain by Jeffrey Walton and Uri Blumenthal. +;; Copyright assigned to the Crypto++ project. + +;; This ASM file provides 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. + +;; set ASFLAGS=/nologo /D_M_X86 /W3 /Cx /Zi /safeseh +;; set ASFLAGS64=/nologo /D_M_X64 /W3 /Cx /Zi +;; "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\ml.exe" %ASFLAGS% /Fo rdrand-x86.obj /c rdrand.asm +;; "C:\Program Files (x86)\Microsoft Visual Studio 11.0\VC\bin\amd64\ml64.exe" %ASFLAGS64% /Fo rdrand-x64.obj /c rdrand.asm + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +TITLE MASM_RDSEED_GenerateBlock source file +SUBTITLE Microsoft specific ASM code to utilize RDSEED for down level Microsoft toolchains + +PUBLIC MASM_RDSEED_GenerateBlock + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +;; C/C++ Function prototypes (both are fastcall) +;; X86: +;; extern "C" void __fastcall MASM_RDSEED_GenerateBlock(byte* ptr, size_t size); +;; X64: +;; extern "C" void __fastcall MASM_RDSEED_GenerateBlock(byte* ptr, size_t size); + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +IFDEF _M_X86 ;; Set via the command line + +.486 +.MODEL FLAT + +;; Fastcall calling conventions exports +ALIAS <@MASM_RDSEED_GenerateBlock@8> = <MASM_RDSEED_GenerateBlock> + +ENDIF + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +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 +RDSEED_GenerateBlock_Top: + + ;; Check remaining size + cmp bsize, 0 + je RDSEED_GenerateBlock_Return + +RDSEED_Call_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 RDSEED_Call_EAX + +RDSEED_succeeded: + + cmp bsize, MWSIZE + jb RDSEED_Partial_Machine_Word + +RDSEED_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 RDSEED_GenerateBlock_Top + + ;; 1,2,3 bytes remain +RDSEED_Partial_Machine_Word: + + ;; Test bit 1 to see if size is at least 2 + test bsize, 2 + jz RDSEED_Bit_1_Not_Set + + mov WORD PTR [buffer], ax + shr eax, 16 + add buffer, 2 + +RDSEED_Bit_1_Not_Set: + + ;; Test bit 0 to see if size is at least 1 + test bsize, 1 + jz RDSEED_Bit_0_Not_Set + + mov BYTE PTR [buffer], al + ;; shr ax, 8 + ;; add buffer, 1 + +RDSEED_Bit_0_Not_Set: + + ;; We've hit all the bits + +RDSEED_GenerateBlock_Return: + + ;; Clear artifacts + xor eax, eax + ret + +MASM_RDSEED_GenerateBlock ENDP + +ENDIF ;; _M_X86 + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +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 +RDSEED_GenerateBlock_Top: + + ;; Check remaining size + cmp bsize, 0 + je RDSEED_GenerateBlock_Return + +RDSEED_Call_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 RDSEED_Call_RAX + +RDSEED_succeeded: + + cmp bsize, MWSIZE + jb RDSEED_Partial_Machine_Word + +RDSEED_Full_Machine_Word: + + mov QWORD PTR [buffer], rax + add buffer, MWSIZE + sub bsize, MWSIZE + + ;; Continue + jmp RDSEED_GenerateBlock_Top + + ;; 1,2,3,4,5,6,7 bytes remain +RDSEED_Partial_Machine_Word: + + ;; Test bit 2 to see if size is at least 4 + test bsize, 4 + jz RDSEED_Bit_2_Not_Set + + mov DWORD PTR [buffer], eax + shr rax, 32 + add buffer, 4 + +RDSEED_Bit_2_Not_Set: + + ;; Test bit 1 to see if size is at least 2 + test bsize, 2 + jz RDSEED_Bit_1_Not_Set + + mov WORD PTR [buffer], ax + shr eax, 16 + add buffer, 2 + +RDSEED_Bit_1_Not_Set: + + ;; Test bit 0 to see if size is at least 1 + test bsize, 1 + jz RDSEED_Bit_0_Not_Set + + mov BYTE PTR [buffer], al + ;; shr ax, 8 + ;; add buffer, 1 + +RDSEED_Bit_0_Not_Set: + + ;; We've hit all the bits + +RDSEED_GenerateBlock_Return: + + ;; Clear artifacts + xor rax, rax + ret + +MASM_RDSEED_GenerateBlock ENDP + +ENDIF ;; _M_X64 + +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; + +END |