107 lines
1.6 KiB
Plaintext
107 lines
1.6 KiB
Plaintext
def datastrlen:
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###############
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# r0 = offset of str in data
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# retval (r0) = strlen
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###############
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push r1
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push r2
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push r3
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movr s2, r0
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movi s1, 0
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lodr s0, s2
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cmpb s0, 0
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jpei exit
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loop:
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movi s2, 0
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addi s1, 1
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addr s2, s1
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lodr s0, s2
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cmpb s0, 0
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jpni loop
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exit:
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movr r0, s1
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poop r3
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poop r2
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poop r1
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retn
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def round: # round(uint16_t text[2])
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#################
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# r0 = offset of text[0] in data
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# r1 = offset of text[1] in data
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# r2 = text[0]
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# r3 = text[1]
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# retval = void
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################
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push r1
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push r2
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push r3
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lodr r2, r0 # text[0]
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lodr r3, r1 # text[1]
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movi s0, 0 # i
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movi s1, 0 # sum
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loop:
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push s0 # saving i
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# s0 and s1 will be used as tmps
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#########
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# calc v1
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#########
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movr s0, r2
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shli s0, 4
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addi s0, 0x7275 # s0 = (text[0] << 4) + k2
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movr s1, r2
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xorr s0, s1 # s0 = ((text[0] << 4) + k2) ^ text[0]
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push s0
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movr s0, r2
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shri s0, 5
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addi s0, 0x6e73 # s0 = (text[0] >> 5) + k3
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poop s1
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xorr s0, s1 # s0 = ((text[0] << 4) + k2) ^ text[0] ^ ((text[0] >> 5) + k3)
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subr r3, s0 # r3 -= s0
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#########
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# calc v0
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#########
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movr s0, r3
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shli s0, 4
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addi s0, 0x7065 # s0 = (text[1] << 4) + k0
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movr s1, r3
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xorr s0, s1 # s0 = ((text[1] << 4) + k0) ^ text[1]
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push s0
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movr s0, r3
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shri s0, 5
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addi s0, 0x7065 # s0 = (text[1] >> 5) + k1
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poop s1
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xorr s0, s1 # s0 = ((text[1] << 4) + k0) ^ text[1] ^ ((text[1] >> 5) + k1)
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subr r2, s0 # r2 -= s0
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######
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# end loop
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#####
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poop s0 # restoring i
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addi s0, 1
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cmpb s0, 127 # while (i < 128)
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jpbi loop
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# saving the values
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strr r0, r2
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strr r1, r3
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poop r3
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poop r2
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poop r1
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retn
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def main:
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movi r0, 0
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call datastrlen
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movr r2, r0
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movi s0, 0
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decrypt:
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push s0
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movi r0, 0
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movi r1, 2
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addr r0, s0
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addr r1, s0
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call round
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poop s0
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addi s0, 4
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cmpr s0, r2
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jpbi decrypt
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shit |