version 1.52, 2013/07/12 00:19:58 |
version 1.54, 2014/01/12 08:13:13 |
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#include <string.h> |
#include <string.h> |
#include <stdarg.h> |
#include <stdarg.h> |
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#include <stdlib.h> |
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#include "xmalloc.h" |
#include "xmalloc.h" |
#include "buffer.h" |
#include "buffer.h" |
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buffer_append(buffer, &ch, 1); |
buffer_append(buffer, &ch, 1); |
} |
} |
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/* Pseudo bignum functions */ |
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void * |
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buffer_get_bignum2_as_string_ret(Buffer *buffer, u_int *length_ptr) |
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{ |
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u_int len; |
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u_char *bin, *p, *ret; |
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if ((p = bin = buffer_get_string_ret(buffer, &len)) == NULL) { |
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error("%s: invalid bignum", __func__); |
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return NULL; |
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} |
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if (len > 0 && (bin[0] & 0x80)) { |
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error("%s: negative numbers not supported", __func__); |
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free(bin); |
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return NULL; |
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} |
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if (len > 8 * 1024) { |
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error("%s: cannot handle BN of size %d", __func__, len); |
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free(bin); |
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return NULL; |
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} |
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/* Skip zero prefix on numbers with the MSB set */ |
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if (len > 1 && bin[0] == 0x00 && (bin[1] & 0x80) != 0) { |
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p++; |
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len--; |
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} |
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ret = xmalloc(len); |
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memcpy(ret, p, len); |
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memset(p, '\0', len); |
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free(bin); |
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return ret; |
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} |
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void * |
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buffer_get_bignum2_as_string(Buffer *buffer, u_int *l) |
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{ |
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void *ret = buffer_get_bignum2_as_string_ret(buffer, l); |
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if (ret == NULL) |
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fatal("%s: buffer error", __func__); |
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return ret; |
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} |
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/* |
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* Stores a string using the bignum encoding rules (\0 pad if MSB set). |
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*/ |
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void |
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buffer_put_bignum2_from_string(Buffer *buffer, const u_char *s, u_int l) |
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{ |
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u_char *buf, *p; |
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int pad = 0; |
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if (l > 8 * 1024) |
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fatal("%s: length %u too long", __func__, l); |
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p = buf = xmalloc(l + 1); |
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/* |
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* If most significant bit is set then prepend a zero byte to |
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* avoid interpretation as a negative number. |
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*/ |
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if (l > 0 && (s[0] & 0x80) != 0) { |
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*p++ = '\0'; |
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pad = 1; |
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} |
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memcpy(p, s, l); |
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buffer_put_string(buffer, buf, l + pad); |
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memset(buf, '\0', l + pad); |
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free(buf); |
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} |
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