[a9494ad] | 1 | |
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| 2 | #include <stdio.h> |
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| 3 | #include <stdlib.h> |
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| 4 | #include <string.h> |
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| 5 | |
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[da5afdf] | 6 | static int debug=0; |
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[a9494ad] | 7 | char* abac_decode_string(char *); |
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| 8 | |
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| 9 | /* encode table */ |
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| 10 | static const char encode64url[]="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
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| 11 | |
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| 12 | /* decode table Tables */ |
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| 13 | /* |
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| 14 | static const char decode64url[]="=====rstuvwxyz========>?@ABCDEFGHIJKLMNOPQRSTUVW======XYZ[\\]^_=abcdefghijklmnopq"; |
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| 15 | */ |
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| 16 | /* 6 14 26 48 5557 65 81*/ |
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| 17 | |
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| 18 | static const char decode64url[]="|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW$$$$$$XYZ[\\]^_`abcdefghijklmnopq"; |
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| 19 | |
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| 20 | /* in 3, out 4 */ |
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| 21 | static void _encode_block( char in[3], char out[4] , int len ) |
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| 22 | { |
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| 23 | out[0] = encode64url[ in[0] >> 2 ]; |
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| 24 | out[1] = encode64url[ ((in[0] & 0x03) << 4) | ((in[1] & 0xf0) >> 4) ]; |
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| 25 | out[2] = (unsigned char) (len > 1 ? encode64url[ ((in[1] & 0x0f) << 2) | ((in[2] & 0xc0) >> 6) ] : '='); |
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| 26 | out[3] = (unsigned char) (len > 2 ? encode64url[ in[2] & 0x3f ] : '='); |
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| 27 | if(0) { |
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| 28 | printf("len: %d\n", len); |
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| 29 | printf("IN: (%c) (%c) (%c)\n", in[0], in[1], in[2]); |
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| 30 | printf("OUT: (%c) (%c) (%c) (%c)\n", out[0], out[1], out[2], out[3]); |
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| 31 | } |
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| 32 | } |
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| 33 | |
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| 34 | /* in 4, out 3 */ |
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| 35 | void _decode_block( char in[4], char out[3] ) |
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| 36 | { |
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| 37 | out[0] = (unsigned char ) (in[0] << 2 | in[1] >> 4); |
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| 38 | out[1] = (unsigned char ) (in[1] << 4 | in[2] >> 2); |
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| 39 | out[2] = (unsigned char ) (((in[2] << 6) & 0xc0) | in[3]); |
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| 40 | if(0) { |
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| 41 | printf("IN: (%c) (%c) (%c) (%c)\n", in[0], in[1], in[2], in[3]); |
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| 42 | printf("OUT: (%c) (%c) (%c)\n", out[0], out[1], out[2]); |
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| 43 | } |
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| 44 | } |
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| 45 | |
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| 46 | |
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| 47 | /* |
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| 48 | return a deep copy of encoded string |
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| 49 | */ |
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| 50 | char* abac_encode_string(char* string) |
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| 51 | { |
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| 52 | char *inbufptr, *outbufptr; |
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| 53 | int len=strlen(string); |
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| 54 | int olen, nlen; |
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| 55 | char *orig_string, *new_string; |
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| 56 | int hops; |
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| 57 | int i; |
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| 58 | |
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| 59 | if(len == 0) return strdup(""); |
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| 60 | |
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| 61 | if((len/3)*3 != len) { |
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| 62 | hops=(len/3)+1; |
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[da5afdf] | 63 | olen=hops*3; |
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[a9494ad] | 64 | orig_string=malloc(sizeof(char)*olen); |
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| 65 | strcpy(orig_string,string); |
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| 66 | for(i=len; i< olen; i++) |
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| 67 | orig_string[i]=0; |
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| 68 | } else { |
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| 69 | hops=len/3; |
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[da5afdf] | 70 | olen=hops*3; |
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[a9494ad] | 71 | orig_string=strdup(string); |
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| 72 | } |
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| 73 | nlen=(olen*4/3 +1); |
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| 74 | new_string = (char *) malloc(sizeof(char)*nlen); |
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| 75 | |
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| 76 | inbufptr=orig_string; |
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| 77 | outbufptr=new_string; |
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[da5afdf] | 78 | if(debug) { |
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| 79 | printf("sizeof string %d\n", len); |
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| 80 | } |
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[a9494ad] | 81 | |
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| 82 | int idx=0; |
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| 83 | for(i=1; i<=hops;i++) { |
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| 84 | int v=(len>(i*3))?3:(len-((i-1)*3)); |
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| 85 | _encode_block(inbufptr,outbufptr,v); |
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| 86 | inbufptr=inbufptr+3; |
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| 87 | outbufptr=outbufptr+4; |
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| 88 | idx=idx+3; |
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| 89 | } |
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| 90 | free(orig_string); |
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| 91 | new_string[nlen-1]='\0'; |
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| 92 | |
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| 93 | if(debug) { |
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| 94 | char *d=abac_decode_string(new_string); |
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| 95 | if(strcmp(d,string) !=0) { |
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| 96 | printf("ERROR, base64 encoding NOT OKAY\n"); |
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| 97 | printf("orig,(%s)\n", string); |
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| 98 | printf("new,(%s)\n", new_string); |
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| 99 | printf("decode,(%s)\n",d); |
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| 100 | } else printf(" base64 encoding OKAY\n"); |
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| 101 | /* free(d); */ |
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| 102 | } |
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| 103 | return new_string; |
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| 104 | } |
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| 105 | |
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| 106 | char* abac_decode_string(char *string) |
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| 107 | { |
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| 108 | char *inbufptr, *outbufptr; |
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| 109 | int len=strlen(string); |
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| 110 | int nlen; |
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| 111 | char *new_string; |
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| 112 | char *orig_string; |
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| 113 | int idx=0; |
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| 114 | int v=0; |
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| 115 | |
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| 116 | if(len==0) return strdup(""); |
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| 117 | int hops=len/4; // ignore any that is not in the size 4 blocks |
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| 118 | new_string=(char *)malloc(sizeof(char)*(hops*3+1)); |
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| 119 | new_string[hops*3]='\0'; |
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| 120 | orig_string=strdup(string); |
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| 121 | |
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| 122 | inbufptr=orig_string; |
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| 123 | outbufptr=new_string; |
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| 124 | char inbuf[4]; |
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| 125 | int i, j; |
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| 126 | |
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| 127 | for(i=1; i<=hops; i++) { |
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| 128 | for(j=0; j<4; j++) { |
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| 129 | char c=inbufptr[j]; |
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| 130 | if(c > 122 || c <43) { |
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| 131 | c=0; |
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| 132 | } else { |
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| 133 | if(0) printf("from %d, (%c)\n", c, c); |
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| 134 | c=decode64url[c-43]; |
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| 135 | if(0) printf("to %d, (%c)\n", c, c); |
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| 136 | } |
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| 137 | if(c) { |
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| 138 | if(c=='$') c=0; |
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| 139 | else c=c-61; |
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| 140 | } |
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| 141 | if(c) { |
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| 142 | inbufptr[j]=(c-1); |
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| 143 | } else { |
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| 144 | inbufptr[j]=0; |
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| 145 | } |
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| 146 | } |
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| 147 | _decode_block( inbufptr, outbufptr ); |
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| 148 | outbufptr=outbufptr+3; |
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| 149 | inbufptr=inbufptr+4; |
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| 150 | } |
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| 151 | free(orig_string); |
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| 152 | return new_string; |
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| 153 | } |
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| 154 | |
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| 155 | |
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| 156 | /***************** |
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| 157 | int main( int argc, char **argv ) |
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| 158 | { |
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| 159 | |
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| 160 | if(argc != 2) return 1; |
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| 161 | |
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| 162 | FILE *infile = fopen( argv[1], "r" ); |
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| 163 | |
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| 164 | int num=1000; |
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| 165 | char *string=(char *)malloc(sizeof(char)*num); |
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| 166 | |
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| 167 | int cnt=getline(&string,&num,infile); |
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| 168 | fclose(infile); |
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| 169 | if(cnt==0) return 0; |
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| 170 | if(string[cnt-1]=='\n') |
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| 171 | string[cnt-1]='\0'; |
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| 172 | |
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| 173 | char *i=abac_encode_string(string); |
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| 174 | printf("encoding into (%s)\n", i); |
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| 175 | char *o=abac_decode_string(i); |
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| 176 | printf("decode into (%s)\n", o); |
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| 177 | |
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| 178 | printf(" %d:%d:%d\n", strlen(string),strlen(i), strlen(o)); |
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| 179 | if(strcmp(string,o)==0) |
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| 180 | printf("OKAY \n"); |
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| 181 | else |
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| 182 | printf("NOT OKAY \n"); |
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| 183 | free(string); |
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| 184 | free(o); |
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| 185 | } |
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| 186 | ****************/ |
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