Import Base64 library

Signed-off-by: Mike Beattie <mike@ethernal.org>

1 files changed, 133 insertions, 0 deletions

diff --git a/Base64/Base64.cpp b/Base64/Base64.cpp
new file mode 100644
index 0000000..62f517f
--- /dev/null
+++ b/Base64/Base64.cpp
@@ -0,0 +1,133 @@
+#include "Base64.h"
+
+const char b64_alphabet[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+		"abcdefghijklmnopqrstuvwxyz"
+		"0123456789+/";
+
+/* 'Private' declarations */
+inline void a3_to_a4(unsigned char * a4, unsigned char * a3);
+inline void a4_to_a3(unsigned char * a3, unsigned char * a4);
+inline unsigned char b64_lookup(char c);
+
+int base64_encode(char *output, char *input, int inputLen) {
+	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 base64_decode(char * output, char * input, int inputLen) {
+	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 base64_enc_len(int plainLen) {
+	int n = plainLen;
+	return (n + 2 - ((n + 2) % 3)) / 3 * 4;
+}
+
+int base64_dec_len(char * input, int inputLen) {
+	int i = 0;
+	int numEq = 0;
+	for(i = inputLen - 1; input[i] == '='; i--) {
+		numEq++;
+	}
+
+	return ((6 * inputLen) / 8) - numEq;
+}
+
+inline void a3_to_a4(unsigned char * a4, unsigned char * a3) {
+	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);
+}
+
+inline void a4_to_a3(unsigned char * a3, unsigned char * a4) {
+	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];
+}
+
+inline unsigned char b64_lookup(char c) {
+	int i;
+	for(i = 0; i < 64; i++) {
+		if(b64_alphabet[i] == c) {
+			return i;
+		}
+	}
+
+	return -1;
+}