int i = 0, j = 0;

int encLen = 0;

unsigned char a3[3];

unsigned char a4[4];

while(inputLen--) {

a3[i++] = *(input++);

if(i == 3) {

a3_to_a4(a4, a3);

for(i = 0; i < 4; i++) {

output[encLen++] = b64_alphabet[a4[i]];

}

i = 0;

}

}

if(i) {

for(j = i; j < 3; j++) {

a3[j] = '\0';

}

a3_to_a4(a4, a3);

for(j = 0; j < i + 1; j++) {

output[encLen++] = b64_alphabet[a4[j]];

}

while((i++ < 3)) {

output[encLen++] = '=';

}

}

output[encLen] = '\0';

return encLen;

int i = 0, j = 0;

int decLen = 0;

unsigned char a3[3];

unsigned char a4[4];

while (inputLen--) {

if(*input == '=') {

break;

}

a4[i++] = *(input++);

if (i == 4) {

for (i = 0; i <4; i++) {

a4[i] = b64_lookup(a4[i]);

}

a4_to_a3(a3,a4);

for (i = 0; i < 3; i++) {

output[decLen++] = a3[i];

}

i = 0;

}

}

if (i) {

for (j = i; j < 4; j++) {

a4[j] = '\0';

}

for (j = 0; j <4; j++) {

a4[j] = b64_lookup(a4[j]);

}

a4_to_a3(a3,a4);

for (j = 0; j < i - 1; j++) {

output[decLen++] = a3[j];

}

}

output[decLen] = '\0';

return decLen;

int i = 0;

int numEq = 0;

for(i = inputLen - 1; input[i] == '='; i--) {

numEq++;

}

return ((6 * inputLen) / 8) - numEq;

a4[0] = (a3[0] & 0xfc) >> 2;

a4[1] = ((a3[0] & 0x03) << 4) + ((a3[1] & 0xf0) >> 4);

a4[2] = ((a3[1] & 0x0f) << 2) + ((a3[2] & 0xc0) >> 6);

a4[3] = (a3[2] & 0x3f);

a3[0] = (a4[0] << 2) + ((a4[1] & 0x30) >> 4);

a3[1] = ((a4[1] & 0xf) << 4) + ((a4[2] & 0x3c) >> 2);

a3[2] = ((a4[2] & 0x3) << 6) + a4[3];

int i;

for(i = 0; i < 64; i++) {

if(b64_alphabet[i] == c) {

return i;

}

}

return -1;