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diff --git a/sshcrc.c b/sshcrc.c
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-/*
- * CRC32 implementation, as used in SSH-1.
- *
- * This particular form of the CRC uses the polynomial
- * P(x) = x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+1
- * and represents polynomials in bit-reversed form, so that the x^0
- * coefficient (constant term) appears in the bit with place value
- * 2^31, and the x^31 coefficient in the bit with place value 2^0. In
- * this representation, (x^32 mod P) = 0xEDB88320, so multiplying the
- * current state by x is done by shifting right by one bit, and XORing
- * that constant into the result if the bit shifted out was 1.
- *
- * There's a bewildering array of subtly different variants of CRC out
- * there, using different polynomials, both bit orders, and varying
- * the start and end conditions. There are catalogue websites such as
- * http://reveng.sourceforge.net/crc-catalogue/ , which generally seem
- * to have the convention of indexing CRCs by their 'check value',
- * defined as whatever you get if you hash the 9-byte test string
- * "123456789".
- *
- * The crc32_rfc1662() function below, which starts off the CRC state
- * at 0xFFFFFFFF and complements it after feeding all the data, gives
- * the check value 0xCBF43926, and matches the hash function that the
- * above catalogue refers to as "CRC-32/ISO-HDLC"; among other things,
- * it's also the "FCS-32" checksum described in RFC 1662 section C.3
- * (hence the name I've given it here).
- *
- * The crc32_ssh1() function implements the variant form used by
- * SSH-1, which uses the same update function, but starts the state at
- * zero and doesn't complement it at the end of the computation. The
- * check value for that version is 0x2DFD2D88, which that CRC
- * catalogue doesn't list at all.
- */
-
-#include <stdint.h>
-#include <stdlib.h>
-
-#include "ssh.h"
-
-/*
- * Multiply a CRC value by x^4. This implementation strategy avoids
- * using a lookup table (which would be a side-channel hazard, since
- * SSH-1 applies this CRC to decrypted session data).
- *
- * The basic idea is that you'd like to "multiply" the shifted-out 4
- * bits by the CRC polynomial value 0xEDB88320, or rather by that
- * value shifted right 3 bits (since you want the _last_ bit shifted
- * out, i.e. the one originally at the 2^3 position, to generate
- * 0xEDB88320 itself). But the scare-quoted "multiply" would have to
- * be a multiplication of polynomials over GF(2), which differs from
- * integer multiplication in that you don't have any carries. In other
- * words, you make a copy of one input shifted left by the index of
- * each set bit in the other, so that adding them all together would
- * give you the ordinary integer product, and then you XOR them
- * together instead.
- *
- * With a 4-bit multiplier, the two kinds of multiplication coincide
- * provided the multiplicand has no two set bits at positions
- * differing by less than 4, because then no two copies of the
- * multiplier can overlap to generate a carry. So I break up the
- * intended multiplicand K = 0xEDB88320 >> 3 into three sub-constants
- * a,b,c with that property, such that a^b^c = K. Then I can multiply
- * m by each of them separately, and XOR together the results.
- */
-static inline uint32_t crc32_shift_4(uint32_t v)
-{
-    const uint32_t a = 0x11111044, b = 0x08840020, c = 0x04220000;
-    uint32_t m = v & 0xF;
-    return (v >> 4) ^ (a*m) ^ (b*m) ^ (c*m);
-}
-
-/*
- * The 8-bit shift you need every time you absorb an input byte,
- * implemented simply by iterating the 4-bit shift twice.
- */
-static inline uint32_t crc32_shift_8(uint32_t v)
-{
-    return crc32_shift_4(crc32_shift_4(v));
-}
-
-/*
- * Update an existing hash value with extra bytes of data.
- */
-uint32_t crc32_update(uint32_t crc, ptrlen data)
-{
-    const uint8_t *p = (const uint8_t *)data.ptr;
-    for (size_t len = data.len; len-- > 0 ;)
-        crc = crc32_shift_8(crc ^ *p++);
-    return crc;
-}
-
-/*
- * The SSH-1 variant of CRC-32.
- */
-uint32_t crc32_ssh1(ptrlen data)
-{
-    return crc32_update(0, data);
-}
-
-/*
- * The official version of CRC-32. Nothing in PuTTY proper uses this,
- * but it's useful to expose it to testcrypt so that we can implement
- * standard test vectors.
- */
-uint32_t crc32_rfc1662(ptrlen data)
-{
-    return crc32_update(0xFFFFFFFF, data) ^ 0xFFFFFFFF;
-}