DAMASK_EICMD/src/base64.f90

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!--------------------------------------------------------------------------------------------------
!> @author Martin Diehl, Max-Planck-Institut für Eisenforschung GmbH
!> @brief Decode Base64 strings.
!> @details See https://en.wikipedia.org/wiki/Base64.
!--------------------------------------------------------------------------------------------------
module base64
use prec
use IO
implicit none
private
character(len=*), parameter :: &
base64_encoding='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
public :: &
base64_init, &
base64_to_bytes, &
base64_nBase64, &
base64_nByte
contains
!--------------------------------------------------------------------------------------------------
!> @brief Do self test.
!--------------------------------------------------------------------------------------------------
subroutine base64_init
write(6,'(/,a)') ' <<<+- base64 init -+>>>'; flush(6)
call selfTest
end subroutine base64_init
!--------------------------------------------------------------------------------------------------
!> @brief Calculate number of Base64 characters required for storage of N bytes.
!--------------------------------------------------------------------------------------------------
pure function base64_nBase64(nByte)
integer(pLongInt), intent(in) :: nByte
integer(pLongInt) :: base64_nBase64
base64_nBase64 = 4_pLongInt * (nByte/3_pLongInt + merge(1_pLongInt,0_pLongInt,mod(nByte,3_pLongInt) /= 0_pLongInt))
end function base64_nBase64
!--------------------------------------------------------------------------------------------------
!> @brief Calculate number of bytes required for storage of N Base64 characters.
!--------------------------------------------------------------------------------------------------
pure function base64_nByte(nBase64)
integer(pLongInt), intent(in) :: nBase64
integer(pLongInt) :: base64_nByte
base64_nByte = 3_pLongInt * (nBase64/4_pLongInt)
end function base64_nByte
!--------------------------------------------------------------------------------------------------
!> @brief Decode Base64 ASCII string into byte-wise binary representation.
!--------------------------------------------------------------------------------------------------
function base64_to_bytes(base64_str,s,e) result(bytes)
character(len=*), intent(in) :: base64_str !< Base64 string representation
integer(pLongInt), intent(in), optional :: &
s, & !< start (in bytes)
e !< end (in bytes)
integer(pLongInt) :: s_bytes, e_bytes, s_str, e_str
integer(C_SIGNED_CHAR), dimension(:), allocatable :: bytes
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if(.not. valid_base64(base64_str)) call IO_error(114,ext_msg='invalid character')
if(present(s)) then
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if(s<1_pLongInt) call IO_error(114, ext_msg='s out of range')
s_str = ((s-1_pLongInt)/3_pLongInt)*4_pLongInt + 1_pLongInt
s_bytes = mod(s-1_pLongInt,3_pLongInt) + 1_pLongInt
else
s_str = 1_pLongInt
s_bytes = 1_pLongInt
endif
if(present(e)) then
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if(e>base64_nByte(len(base64_str,kind=pLongInt))) call IO_error(114, ext_msg='e out of range')
e_str = ((e-1_pLongInt)/3_pLongInt)*4_pLongInt + 4_pLongInt
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e_bytes = e - base64_nByte(s_str)
else
e_str = len(base64_str,kind=pLongInt)
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e_bytes = base64_nByte(len(base64_str,kind=pLongInt)) - base64_nByte(s_str)
if(base64_str(e_str-0_pLongInt:e_str-0_pLongInt) == '=') e_bytes = e_bytes - 1_pLongInt
if(base64_str(e_str-1_pLongInt:e_str-1_pLongInt) == '=') e_bytes = e_bytes - 1_pLongInt
endif
bytes = decode_base64(base64_str(s_str:e_str))
bytes = bytes(s_bytes:e_bytes)
end function base64_to_bytes
!--------------------------------------------------------------------------------------------------
!> @brief Convert a Base64 ASCII string into its byte-wise binary representation.
!--------------------------------------------------------------------------------------------------
pure function decode_base64(base64_str) result(bytes)
character(len=*), intent(in) :: base64_str !< Base64 string representation
integer(C_SIGNED_CHAR), dimension(base64_nByte(len(base64_str,pLongInt))) :: bytes
integer(C_SIGNED_CHAR), dimension(0:3) :: charPos
integer(pLongInt) :: c, b, p
c = 1_pLongInt
b = 1_pLongInt
do while(c < len(base64_str,kind=pLongInt))
do p=0_pLongInt,3_pLongInt
if(c+p<=len(base64_str,kind=pLongInt)) then
charPos(p) = int(index(base64_encoding,base64_str(c+p:c+p))-1,C_SIGNED_CHAR)
else
charPos(p) = 0_C_SIGNED_CHAR
endif
enddo
call mvbits(charPos(0),0,6,bytes(b+0),2)
call mvbits(charPos(1),4,2,bytes(b+0),0)
call mvbits(charPos(1),0,4,bytes(b+1),4)
call mvbits(charPos(2),2,4,bytes(b+1),0)
call mvbits(charPos(2),0,2,bytes(b+2),6)
call mvbits(charPos(3),0,6,bytes(b+2),0)
b = b+3_pLongInt
c = c+4_pLongInt
enddo
end function decode_base64
!--------------------------------------------------------------------------------------------------
!> @brief Test for valid Base64 encoded string.
!> @details Input string must be properly padded.
!--------------------------------------------------------------------------------------------------
pure logical function valid_base64(base64_str)
character(len=*), intent(in) :: base64_str !< Base64 string representation
integer(pLongInt) :: l
l = len(base64_str,pLongInt)
valid_base64 = .true.
if(mod(l,4_pLongInt)/=0_pLongInt .or. l < 4_pInt) valid_base64 = .false.
if(verify(base64_str(:l-2_pLongInt),base64_encoding, kind=pLongInt) /= 0_pLongInt) valid_base64 = .false.
if(verify(base64_str(l-1_pLongInt:),base64_encoding//'=',kind=pLongInt) /= 0_pLongInt) valid_base64 = .false.
end function valid_base64
!--------------------------------------------------------------------------------------------------
!> @brief Check correctness of base64 functions.
!--------------------------------------------------------------------------------------------------
subroutine selfTest
integer(C_SIGNED_CHAR), dimension(:), allocatable :: bytes
character(len=*), parameter :: zero_to_three = 'AAECAw=='
! https://en.wikipedia.org/wiki/Base64#Output_padding
if(base64_nBase64(20_pLongInt) /= 28_pLongInt) call IO_error(0,ext_msg='base64_nBase64/20/28')
if(base64_nBase64(19_pLongInt) /= 28_pLongInt) call IO_error(0,ext_msg='base64_nBase64/19/28')
if(base64_nBase64(18_pLongInt) /= 24_pLongInt) call IO_error(0,ext_msg='base64_nBase64/18/24')
if(base64_nBase64(17_pLongInt) /= 24_pLongInt) call IO_error(0,ext_msg='base64_nBase64/17/24')
if(base64_nBase64(16_pLongInt) /= 24_pLongInt) call IO_error(0,ext_msg='base64_nBase64/16/24')
if(base64_nByte(4_pLongInt) /= 3_pLongInt) call IO_error(0,ext_msg='base64_nByte/4/3')
if(base64_nByte(8_pLongInt) /= 6_pLongInt) call IO_error(0,ext_msg='base64_nByte/8/6')
bytes = base64_to_bytes(zero_to_three)
if(any(bytes /= int([0,1,2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 4) call IO_error(0,ext_msg='base64_to_bytes//')
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bytes = base64_to_bytes(zero_to_three,e=1_pLongInt)
if(any(bytes /= int([0],C_SIGNED_CHAR)) .or. size(bytes) /= 1) call IO_error(0,ext_msg='base64_to_bytes//1')
bytes = base64_to_bytes(zero_to_three,e=2_pLongInt)
if(any(bytes /= int([0,1],C_SIGNED_CHAR)) .or. size(bytes) /= 2) call IO_error(0,ext_msg='base64_to_bytes//2')
bytes = base64_to_bytes(zero_to_three,e=3_pLongInt)
if(any(bytes /= int([0,1,2],C_SIGNED_CHAR)) .or. size(bytes) /= 3) call IO_error(0,ext_msg='base64_to_bytes//3')
bytes = base64_to_bytes(zero_to_three,e=4_pLongInt)
if(any(bytes /= int([0,1,2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 4) call IO_error(0,ext_msg='base64_to_bytes//4')
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bytes = base64_to_bytes(zero_to_three,s=1_pLongInt)
if(any(bytes /= int([0,1,2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 4) call IO_error(0,ext_msg='base64_to_bytes/1/')
bytes = base64_to_bytes(zero_to_three,s=2_pLongInt)
if(any(bytes /= int([1,2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 3) call IO_error(0,ext_msg='base64_to_bytes/2/')
bytes = base64_to_bytes(zero_to_three,s=3_pLongInt)
if(any(bytes /= int([2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 2) call IO_error(0,ext_msg='base64_to_bytes/3/')
bytes = base64_to_bytes(zero_to_three,s=4_pLongInt)
if(any(bytes /= int([3],C_SIGNED_CHAR)) .or. size(bytes) /= 1) call IO_error(0,ext_msg='base64_to_bytes/4/')
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bytes = base64_to_bytes(zero_to_three,s=1_pLongInt,e=1_pLongInt)
if(any(bytes /= int([0],C_SIGNED_CHAR)) .or. size(bytes) /= 1) call IO_error(0,ext_msg='base64_to_bytes/1/1')
bytes = base64_to_bytes(zero_to_three,s=2_pLongInt,e=2_pLongInt)
if(any(bytes /= int([1],C_SIGNED_CHAR)) .or. size(bytes) /= 1) call IO_error(0,ext_msg='base64_to_bytes/2/2')
bytes = base64_to_bytes(zero_to_three,s=3_pLongInt,e=3_pLongInt)
if(any(bytes /= int([2],C_SIGNED_CHAR)) .or. size(bytes) /= 1) call IO_error(0,ext_msg='base64_to_bytes/3/3')
bytes = base64_to_bytes(zero_to_three,s=4_pLongInt,e=4_pLongInt)
if(any(bytes /= int([3],C_SIGNED_CHAR)) .or. size(bytes) /= 1) call IO_error(0,ext_msg='base64_to_bytes/4/4')
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bytes = base64_to_bytes(zero_to_three,s=1_pLongInt,e=2_pLongInt)
if(any(bytes /= int([0,1],C_SIGNED_CHAR)) .or. size(bytes) /= 2) call IO_error(0,ext_msg='base64_to_bytes/1/2')
bytes = base64_to_bytes(zero_to_three,s=2_pLongInt,e=3_pLongInt)
if(any(bytes /= int([1,2],C_SIGNED_CHAR)) .or. size(bytes) /= 2) call IO_error(0,ext_msg='base64_to_bytes/2/3')
bytes = base64_to_bytes(zero_to_three,s=3_pLongInt,e=4_pLongInt)
if(any(bytes /= int([2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 2) call IO_error(0,ext_msg='base64_to_bytes/3/4')
bytes = base64_to_bytes(zero_to_three,s=1_pLongInt,e=3_pLongInt)
if(any(bytes /= int([0,1,2],C_SIGNED_CHAR)) .or. size(bytes) /= 3) call IO_error(0,ext_msg='base64_to_bytes/1/3')
bytes = base64_to_bytes(zero_to_three,s=2_pLongInt,e=4_pLongInt)
if(any(bytes /= int([1,2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 3) call IO_error(0,ext_msg='base64_to_bytes/2/4')
bytes = base64_to_bytes(zero_to_three,s=1_pLongInt,e=4_pLongInt)
if(any(bytes /= int([0,1,2,3],C_SIGNED_CHAR)) .or. size(bytes) /= 4) call IO_error(0,ext_msg='base64_to_bytes/1/4')
end subroutine selfTest
end module base64