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;
95 if (plainchar == plaintextend)
97 state_in->result = result;
98 state_in->step = step_B;
99 return codechar - code_out;
101 fragment = *plainchar++;
102 result |= (fragment & 0x0f0) >> 4;
103 *codechar++ = base64_encode_value(result);
104 result = (fragment & 0x00f) << 2;
106 if (plainchar == plaintextend)
108 state_in->result = result;
109 state_in->step = step_C;
110 return codechar - code_out;
112 fragment = *plainchar++;
113 result |= (fragment & 0x0c0) >> 6;
114 *codechar++ = base64_encode_value(result);
115 result = (fragment & 0x03f) >> 0;
116 *codechar++ = base64_encode_value(result);
118 ++(state_in->stepcount);
121 /* control should not reach here */
122 return codechar - code_out;
125 static int base64_encode_blockend(char* code_out, base64_encodestate* state_in)
127 char* codechar = code_out;
129 switch (state_in->step)
132 *codechar++ = base64_encode_value(state_in->result);
137 *codechar++ = base64_encode_value(state_in->result);
145 return codechar - code_out;
149 cdecoder.c - c source to a base64 decoding algorithm implementation
151 This is part of the libb64 project, and has been placed in the public domain.
152 For details, see http://sourceforge.net/projects/libb64
155 static int base64_decode_value(char value_in)
157 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};
158 static const char decoding_size = sizeof(decoding);
160 if (value_in < 0 || value_in >= decoding_size) return -1;
161 return decoding[(int)value_in];
164 static void base64_init_decodestate(base64_decodestate* state_in)
166 state_in->step = step_a;
167 state_in->plainchar = 0;
170 static int base64_decode_block(const char* code_in, const int length_in, unsigned char* plaintext_out, base64_decodestate* state_in)
172 const char* codechar = code_in;
173 unsigned char* plainchar = plaintext_out;
176 *plainchar = state_in->plainchar;
178 switch (state_in->step)
184 if (codechar == code_in+length_in)
186 state_in->step = step_a;
187 state_in->plainchar = *plainchar;
188 return plainchar - plaintext_out;
190 fragment = (char)base64_decode_value(*codechar++);
191 } while (fragment < 0);
192 *plainchar = (fragment & 0x03f) << 2;
195 if (codechar == code_in+length_in)
197 state_in->step = step_b;
198 state_in->plainchar = *plainchar;
199 return plainchar - plaintext_out;
201 fragment = (char)base64_decode_value(*codechar++);
202 } while (fragment < 0);
203 *plainchar++ |= (fragment & 0x030) >> 4;
204 *plainchar = (fragment & 0x00f) << 4;
207 if (codechar == code_in+length_in)
209 state_in->step = step_c;
210 state_in->plainchar = *plainchar;
211 return plainchar - plaintext_out;
213 fragment = (char)base64_decode_value(*codechar++);
214 } while (fragment < 0);
215 *plainchar++ |= (fragment & 0x03c) >> 2;
216 *plainchar = (fragment & 0x003) << 6;
219 if (codechar == code_in+length_in)
221 state_in->step = step_d;
222 state_in->plainchar = *plainchar;
223 return plainchar - plaintext_out;
225 fragment = (char)base64_decode_value(*codechar++);
226 } while (fragment < 0);
227 *plainchar++ |= (fragment & 0x03f);
230 /* control should not reach here */
231 return plainchar - plaintext_out;
234 int b64_encode(const unsigned char *src, const int ssize,
235 char *const b64, int *const bsize)
237 base64_encodestate s;
241 if (*bsize < ((ssize-1)/3+1)*4+1) return 1;
242 base64_init_encodestate(&s);
243 cnt1 = base64_encode_block(src, ssize, c, &s);
245 cnt2 = base64_encode_blockend(c, &s);
248 *bsize = cnt1 + cnt2;
252 int b64_decode(const char *b64, unsigned char *const dst, int *const dsize)
254 base64_decodestate s;
256 int bsize = strlen(b64);
258 if (*dsize < (bsize*3/4)) return 1;
259 base64_init_decodestate(&s);
260 cnt = base64_decode_block(b64, bsize, dst, &s);