/* R_ENCODE.H - RFC 1113 encoding and decoding routines
*/
/* Copyright (C) 1991-2 RSA Laboratories, a division of RSA Data
Security, Inc. All rights reserved.
*/
#include "global.h"
#include "rsaref.h"
#include "r_encode.h"
/* RFC 1113 encoding:
Value Encoding Value Encoding Value Encoding Value Encoding
0 A 17 R 34 i 51 z
1 B 18 S 35 j 52 0
2 C 19 T 36 k 53 1
3 D 20 U 37 l 54 2
4 E 21 V 38 m 55 3
5 F 22 W 39 n 56 4
6 G 23 X 40 o 57 5
7 H 24 Y 41 p 58 6
8 I 25 Z 42 q 59 7
9 J 26 a 43 r 60 8
10 K 27 b 44 s 61 9
11 L 28 c 45 t 62 +
12 M 29 d 46 u 63 /
13 N 30 e 47 v
14 O 31 f 48 w (pad) =
15 P 32 g 49 x
16 Q 33 h 50 y
*/
#define ENCODING(i) \
(unsigned char)(((i) < 26) ? ((i) + 0x41) : \
(((i) < 52) ? ((i) - 26 + 0x61) : \
(((i) < 62) ? ((i) - 52 + 0x30) : \
(((i) == 62) ? 0x2b : 0x2f))))
#define ENCODING_PAD 0x3d
#define IS_ENCODING(c) \
((((c) >= 0x41) && ((c) <= 0x5a)) || \
(((c) >= 0x61) && ((c) <= 0x7a)) || \
(((c) >= 0x30) && ((c) <= 0x39)) || \
((c) == 0x2b) || \
((c) == 0x2f))
/* assumes IS_ENCODING (c) == 1 */
#define DECODING(c) \
(((c) == 0x2b) ? 62 : \
(((c) == 0x2f) ? 63 : \
(((c) <= 0x39) ? ((c) - 0x30 + 52) : \
(((c) <= 0x5a) ? ((c) - 0x41) : ((c) - 0x61 + 26)))))
static void EncodeQuantum PROTO_LIST ((unsigned char [4], unsigned char [3]));
static int DecodeQuantum PROTO_LIST ((unsigned char [3], unsigned char [4]));
static void EncodeLastQuantum
PROTO_LIST ((unsigned char [4], unsigned char *, unsigned int));
static int DecodeLastQuantum
PROTO_LIST ((unsigned char *, unsigned int *, unsigned char [4]));
void R_EncodePEMBlock (encodedBlock, encodedBlockLen, block, blockLen)
unsigned char *encodedBlock; /* encoded block */
unsigned int *encodedBlockLen; /* length of encoded block */
unsigned char *block; /* block */
unsigned int blockLen; /* length of block */
{
unsigned int i, lastLen;
if (blockLen < 1) {
*encodedBlockLen = 0;
return;
}
for (i = 0; i < (blockLen-1)/3; i++)
EncodeQuantum (&encodedBlock[4*i], &block[3*i]);
lastLen = blockLen - 3*i;
EncodeLastQuantum (&encodedBlock[4*i], &block[3*i], lastLen);
*encodedBlockLen = 4*i + 4;
}
int R_DecodePEMBlock (block, blockLen, encodedBlock, encodedBlockLen)
unsigned char *block; /* block */
unsigned int *blockLen; /* length of block */
unsigned char *encodedBlock; /* encoded block */
unsigned int encodedBlockLen; /* length of encoded block */
{
int status;
unsigned int i, lastLen;
if (encodedBlockLen % 4)
return (RE_ENCODING);
if (encodedBlockLen < 1) {
*blockLen = 0;
return (0);
}
for (i = 0; i < (encodedBlockLen-1)/4; i++)
if (status = DecodeQuantum (&block[3*i], &encodedBlock[4*i]))
return (status);
if (status = DecodeLastQuantum (&block[3*i], &lastLen, &encodedBlock[4*i]))
return (status);
*blockLen = 3*i + lastLen;
return (0);
}
static void EncodeQuantum (encodedQuantum, quantum)
unsigned char encodedQuantum[4];
unsigned char quantum[3];
{
UINT4 temp;
unsigned int a, b, c, d;
temp = ((UINT4)quantum[0]) << 16;
temp |= ((UINT4)quantum[1]) << 8;
temp |= (UINT4)quantum[2];
a = (unsigned int)((temp >> 18) & 0x3f);
b = (unsigned int)((temp >> 12) & 0x3f);
c = (unsigned int)((temp >> 6) & 0x3f);
d = (unsigned int)(temp & 0x3f);
encodedQuantum[0] = ENCODING (a);
encodedQuantum[1] = ENCODING (b);
encodedQuantum[2] = ENCODING (c);
encodedQuantum[3] = ENCODING (d);
/* Zeroize potentially sensitive information.
*/
temp = 0;
a = b = c = d = 0;
}
static int DecodeQuantum (quantum, encodedQuantum)
unsigned char quantum[3];
unsigned char encodedQuantum[4];
{
UINT4 temp;
unsigned int a, b, c, d;
if (! IS_ENCODING (encodedQuantum[0]) ||
! IS_ENCODING (encodedQuantum[1]) ||
! IS_ENCODING (encodedQuantum[2]) ||
! IS_ENCODING (encodedQuantum[3]))
return (RE_ENCODING);
a = DECODING (encodedQuantum[0]);
b = DECODING (encodedQuantum[1]);
c = DECODING (encodedQuantum[2]);
d = DECODING (encodedQuantum[3]);
temp = ((UINT4)a) << 18;
temp |= ((UINT4)b) << 12;
temp |= ((UINT4)c) << 6;
temp |= (UINT4)d;
quantum[0] = (unsigned char)(temp >> 16);
quantum[1] = (unsigned char)(temp >> 8);
quantum[2] = (unsigned char)temp;
/* Zeroize potentially sensitive information.
*/
temp = 0;
a = b = c = d = 0;
return (0);
}
static void EncodeLastQuantum (encodedQuantum, quantum, quantumLen)
unsigned char encodedQuantum[4];
unsigned char *quantum;
unsigned int quantumLen; /* 1, 2 or 3 */
{
UINT4 temp;
unsigned int a, b, c, d;
temp = ((UINT4)quantum[0]) << 16;
if (quantumLen >= 2)
temp |= ((UINT4)quantum[1]) << 8;
if (quantumLen == 3)
temp |= ((UINT4)quantum[2]);
a = (unsigned int)((temp >> 18) & 0x3f);
b = (unsigned int)((temp >> 12) & 0x3f);
if (quantumLen >= 2)
c = (unsigned int)((temp >> 6) & 0x3f);
if (quantumLen == 3)
d = (unsigned int)(temp & 0x3f);
encodedQuantum[0] = ENCODING (a);
encodedQuantum[1] = ENCODING (b);
if (quantumLen >= 2)
encodedQuantum[2] = ENCODING (c);
else
encodedQuantum[2] = ENCODING_PAD;
if (quantumLen == 3)
encodedQuantum[3] = ENCODING (d);
else
encodedQuantum[3] = ENCODING_PAD;
/* Zeroize potentially sensitive information.
*/
temp = 0;
a = b = c = d = 0;
}
static int DecodeLastQuantum (quantum, quantumLen, encodedQuantum)
unsigned char *quantum;
unsigned int *quantumLen; /* 1, 2 or 3 */
unsigned char encodedQuantum[4];
{
UINT4 temp;
unsigned int a, b, c, d;
if (! IS_ENCODING (encodedQuantum[0]) ||
! IS_ENCODING (encodedQuantum[1]) ||
(! IS_ENCODING (encodedQuantum[2]) &&
(encodedQuantum[2] != ENCODING_PAD)) ||
(! IS_ENCODING (encodedQuantum[3]) &&
(encodedQuantum[3] != ENCODING_PAD)))
return (RE_ENCODING);
if (encodedQuantum[2] == ENCODING_PAD)
*quantumLen = 1;
else if (encodedQuantum[3] == ENCODING_PAD)
*quantumLen = 2;
else
*quantumLen = 3;
a = DECODING (encodedQuantum[0]);
b = DECODING (encodedQuantum[1]);
if (*quantumLen >= 2)
c = DECODING (encodedQuantum[2]);
if (*quantumLen == 3)
d = DECODING (encodedQuantum[3]);
temp = ((UINT4)a) << 18;
temp |= ((UINT4)b) << 12;
if (*quantumLen >= 2)
temp |= ((UINT4)c) << 6;
if (*quantumLen == 3)
temp |= ((UINT4)d);
quantum[0] = (unsigned char)(temp >> 16);
if (*quantumLen >= 2)
quantum[1] = (unsigned char)(temp >> 8);
if (*quantumLen == 3)
quantum[2] = (unsigned char)temp;
/* Zeroize potentially sensitive information.
*/
temp = 0;
a = b = c = d = 0;
return (0);
}
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