lib/isc/base32.c

126 base32_decode_init(base32_decode_ctx_t *ctx, int length, const char base[],
129 	ctx->digits = 0;
130 	ctx->seen_end = 0;
131 	ctx->seen_32 = 0;
132 	ctx->length = length;
133 	ctx->target = target;
134 	ctx->base = base;
135 	ctx->pad = pad;
139 base32_decode_char(base32_decode_ctx_t *ctx, int c) {
143 	if (ctx->seen_end)
145 	if ((s = strchr(ctx->base, c)) == NULL)
147 	last = (unsigned int)(s - ctx->base);
158 	if (last != 32 && ctx->seen_32 != 0)
164 	if (last == 32 && !ctx->pad)
172 	if (last == 32 && ctx->seen_32 == 0)
173 		switch (ctx->digits) {
178 			if ((ctx->val[1]&0x03) != 0)
180 			ctx->seen_32 = 1;
185 			if ((ctx->val[3]&0x0f) != 0)
187 			ctx->seen_32 = 3;
190 			if ((ctx->val[4]&0x01) != 0)
192 			ctx->seen_32 = 3;
197 			if ((ctx->val[6]&0x07) != 0)
199 			ctx->seen_32 = 4;
206 	ctx->val[ctx->digits++] = (last == 32) ? 0 : last;
208 	if (ctx->digits == 8) {
212 		if (ctx->seen_32 != 0) {
213 			ctx->seen_end = 1;
214 			n = ctx->seen_32;
216 		buf[0] = (ctx->val[0]<<3)|(ctx->val[1]>>2);
217 		buf[1] = (ctx->val[1]<<6)|(ctx->val[2]<<1)|(ctx->val[3]>>4);
218 		buf[2] = (ctx->val[3]<<4)|(ctx->val[4]>>1);
219 		buf[3] = (ctx->val[4]<<7)|(ctx->val[5]<<2)|(ctx->val[6]>>3);
220 		buf[4] = (ctx->val[6]<<5)|(ctx->val[7]);
221 		RETERR(isc_mem_tobuffer(ctx->target, buf, n));
222 		if (ctx->length >= 0) {
223 			if (n > ctx->length)
226 				ctx->length -= n;
228 		ctx->digits = 0;
234 base32_decode_finish(base32_decode_ctx_t *ctx) {
236 	if (ctx->length > 0)
241 	if (!ctx->pad && ctx->digits != 0) {
242 		ctx->pad = 1;
244 			RETERR(base32_decode_char(ctx, '='));
245 		} while (ctx->digits != 0);
247 	if (ctx->digits != 0)
256 	base32_decode_ctx_t ctx;
258 	base32_decode_init(&ctx, -1, base, pad, target);
261 		RETERR(base32_decode_char(&ctx, c));
264 	RETERR(base32_decode_finish(&ctx));