2 cencoder.c - c source to a base64 encoding algorithm implementation
4 This is part of the libb64 project, and has been placed in the public domain.
5 For details, see http://sourceforge.net/projects/libb64
9 Modified by Eugene Crosser to fit pam_pcsc_cr project, 2013
15 cencode.h - c header for a base64 encoding algorithm
17 This is part of the libb64 project, and has been placed in the public domain.
18 For details, see http://sourceforge.net/projects/libb64
22 Modified by Eugene Crosser to fit pam_pcsc_cr project, 2013
27 step_A, step_B, step_C
32 base64_encodestep step;
38 cdecode.h - c header for a base64 decoding algorithm
40 This is part of the libb64 project, and has been placed in the public domain.
41 For details, see http://sourceforge.net/projects/libb64
46 step_a, step_b, step_c, step_d
51 base64_decodestep step;
55 static void base64_init_encodestate(base64_encodestate* state_in)
57 state_in->step = step_A;
59 state_in->stepcount = 0;
62 static char base64_encode_value(char value_in)
64 static const char* encoding = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
65 if (value_in > 63) return '=';
66 return encoding[(int)value_in];
69 static int base64_encode_block(const unsigned char* plaintext_in, int length_in, char* code_out, base64_encodestate* state_in)
71 const unsigned char* plainchar = plaintext_in;
72 const unsigned char* const plaintextend = plaintext_in + length_in;
73 char* codechar = code_out;
77 result = state_in->result;
79 switch (state_in->step)
84 if (plainchar == plaintextend)
86 state_in->result = result;
87 state_in->step = step_A;
88 return codechar - code_out;
90 fragment = *plainchar++;
91 result = (fragment & 0x0fc) >> 2;
92 *codechar++ = base64_encode_value(result);
93 result = (fragment & 0x003) << 4;
96 if (plainchar == plaintextend)
98 state_in->result = result;
99 state_in->step = step_B;
100 return codechar - code_out;
102 fragment = *plainchar++;
103 result |= (fragment & 0x0f0) >> 4;
104 *codechar++ = base64_encode_value(result);
105 result = (fragment & 0x00f) << 2;
108 if (plainchar == plaintextend)
110 state_in->result = result;
111 state_in->step = step_C;
112 return codechar - code_out;
114 fragment = *plainchar++;
115 result |= (fragment & 0x0c0) >> 6;
116 *codechar++ = base64_encode_value(result);
117 result = (fragment & 0x03f) >> 0;
118 *codechar++ = base64_encode_value(result);
120 ++(state_in->stepcount);
123 /* control should not reach here */
124 return codechar - code_out;
127 static int base64_encode_blockend(char* code_out, base64_encodestate* state_in)
129 char* codechar = code_out;
131 switch (state_in->step)
134 *codechar++ = base64_encode_value(state_in->result);
139 *codechar++ = base64_encode_value(state_in->result);
146 return codechar - code_out;
150 cdecoder.c - c source to a base64 decoding algorithm implementation
152 This is part of the libb64 project, and has been placed in the public domain.
153 For details, see http://sourceforge.net/projects/libb64
156 static int base64_decode_value(char value_in)
158 static const char decoding[] = {62,-1,-1,-1,63,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-2,-1,-1,-1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51};
159 static const char decoding_size = sizeof(decoding);
161 if (value_in < 0 || value_in >= decoding_size) return -1;
162 return decoding[(int)value_in];
165 static void base64_init_decodestate(base64_decodestate* state_in)
167 state_in->step = step_a;
168 state_in->plainchar = 0;
171 static int base64_decode_block(const char* code_in, const int length_in, unsigned char* plaintext_out, base64_decodestate* state_in)
173 const char* codechar = code_in;
174 unsigned char* plainchar = plaintext_out;
177 *plainchar = state_in->plainchar;
179 switch (state_in->step)
185 if (codechar == code_in+length_in)
187 state_in->step = step_a;
188 state_in->plainchar = *plainchar;
189 return plainchar - plaintext_out;
191 fragment = (char)base64_decode_value(*codechar++);
192 } while (fragment < 0);
193 *plainchar = (fragment & 0x03f) << 2;
197 if (codechar == code_in+length_in)
199 state_in->step = step_b;
200 state_in->plainchar = *plainchar;
201 return plainchar - plaintext_out;
203 fragment = (char)base64_decode_value(*codechar++);
204 } while (fragment < 0);
205 *plainchar++ |= (fragment & 0x030) >> 4;
206 *plainchar = (fragment & 0x00f) << 4;
210 if (codechar == code_in+length_in)
212 state_in->step = step_c;
213 state_in->plainchar = *plainchar;
214 return plainchar - plaintext_out;
216 fragment = (char)base64_decode_value(*codechar++);
217 } while (fragment < 0);
218 *plainchar++ |= (fragment & 0x03c) >> 2;
219 *plainchar = (fragment & 0x003) << 6;
223 if (codechar == code_in+length_in)
225 state_in->step = step_d;
226 state_in->plainchar = *plainchar;
227 return plainchar - plaintext_out;
229 fragment = (char)base64_decode_value(*codechar++);
230 } while (fragment < 0);
231 *plainchar++ |= (fragment & 0x03f);
234 /* control should not reach here */
235 return plainchar - plaintext_out;
238 int b64_encode(const unsigned char *src, const int ssize,
239 char *const b64, int *const bsize)
241 base64_encodestate s;
245 if (*bsize < ((ssize-1)/3+1)*4+1) return 1;
246 base64_init_encodestate(&s);
247 cnt1 = base64_encode_block(src, ssize, c, &s);
249 cnt2 = base64_encode_blockend(c, &s);
252 *bsize = cnt1 + cnt2;
256 int b64_decode(const char *b64, unsigned char *const dst, int *const dsize)
258 base64_decodestate s;
260 int bsize = strlen(b64);
262 if (*dsize < (bsize*3/4)) return 1;
263 base64_init_decodestate(&s);
264 cnt = base64_decode_block(b64, bsize, dst, &s);