107 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			107 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| 
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| #include <linux/errno.h>
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| 
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| int ceph_armor(char *dst, const char *src, const char *end);
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| int ceph_unarmor(char *dst, const char *src, const char *end);
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| 
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| /*
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|  * base64 encode/decode.
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|  */
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| 
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| static const char *pem_key =
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| 	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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| 
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| static int encode_bits(int c)
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| {
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| 	return pem_key[c];
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| }
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| 
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| static int decode_bits(char c)
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| {
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| 	if (c >= 'A' && c <= 'Z')
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| 		return c - 'A';
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| 	if (c >= 'a' && c <= 'z')
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| 		return c - 'a' + 26;
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| 	if (c >= '0' && c <= '9')
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| 		return c - '0' + 52;
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| 	if (c == '+')
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| 		return 62;
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| 	if (c == '/')
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| 		return 63;
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| 	if (c == '=')
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| 		return 0; /* just non-negative, please */
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| 	return -EINVAL;
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| }
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| 
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| int ceph_armor(char *dst, const char *src, const char *end)
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| {
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| 	int olen = 0;
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| 	int line = 0;
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| 
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| 	while (src < end) {
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| 		unsigned char a, b, c;
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| 
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| 		a = *src++;
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| 		*dst++ = encode_bits(a >> 2);
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| 		if (src < end) {
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| 			b = *src++;
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| 			*dst++ = encode_bits(((a & 3) << 4) | (b >> 4));
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| 			if (src < end) {
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| 				c = *src++;
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| 				*dst++ = encode_bits(((b & 15) << 2) |
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| 						     (c >> 6));
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| 				*dst++ = encode_bits(c & 63);
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| 			} else {
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| 				*dst++ = encode_bits((b & 15) << 2);
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| 				*dst++ = '=';
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| 			}
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| 		} else {
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| 			*dst++ = encode_bits(((a & 3) << 4));
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| 			*dst++ = '=';
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| 			*dst++ = '=';
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| 		}
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| 		olen += 4;
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| 		line += 4;
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| 		if (line == 64) {
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| 			line = 0;
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| 			*(dst++) = '\n';
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| 			olen++;
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| 		}
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| 	}
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| 	return olen;
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| }
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| 
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| int ceph_unarmor(char *dst, const char *src, const char *end)
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| {
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| 	int olen = 0;
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| 
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| 	while (src < end) {
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| 		int a, b, c, d;
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| 
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| 		if (src[0] == '\n') {
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| 			src++;
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| 			continue;
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| 		}
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| 		if (src + 4 > end)
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| 			return -EINVAL;
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| 		a = decode_bits(src[0]);
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| 		b = decode_bits(src[1]);
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| 		c = decode_bits(src[2]);
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| 		d = decode_bits(src[3]);
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| 		if (a < 0 || b < 0 || c < 0 || d < 0)
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| 			return -EINVAL;
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| 
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| 		*dst++ = (a << 2) | (b >> 4);
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| 		if (src[2] == '=')
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| 			return olen + 1;
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| 		*dst++ = ((b & 15) << 4) | (c >> 2);
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| 		if (src[3] == '=')
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| 			return olen + 2;
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| 		*dst++ = ((c & 3) << 6) | d;
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| 		olen += 3;
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| 		src += 4;
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| 	}
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| 	return olen;
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| }
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