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Change contrib/laxder from headers-only to files compilable as standa…
…lone C Verified that both programs compile with gcc -I. -I../include -lsecp256k1 -c -W -Wextra -Wall -Werror -ansi -pedantic lax_der_privatekey_parsing.c gcc -I. -I../include -lsecp256k1 -c -W -Wextra -Wall -Werror -ansi -pedantic lax_der_parsing.c
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Original file line number | Diff line number | Diff line change |
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/********************************************************************** | ||
* Copyright (c) 2015 Pieter Wuille * | ||
* Distributed under the MIT software license, see the accompanying * | ||
* file COPYING or http://www.opensource.org/licenses/mit-license.php.* | ||
**********************************************************************/ | ||
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#include <string.h> | ||
#include <secp256k1.h> | ||
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#include "lax_der_parsing.h" | ||
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int ecdsa_signature_parse_der_lax(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input, size_t inputlen) { | ||
size_t rpos, rlen, spos, slen; | ||
size_t pos = 0; | ||
size_t lenbyte; | ||
unsigned char tmpsig[64] = {0}; | ||
int overflow = 0; | ||
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/* Hack to initialize sig with a correctly-parsed but invalid signature. */ | ||
secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig); | ||
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/* Sequence tag byte */ | ||
if (pos == inputlen || input[pos] != 0x30) { | ||
return 0; | ||
} | ||
pos++; | ||
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/* Sequence length bytes */ | ||
if (pos == inputlen) { | ||
return 0; | ||
} | ||
lenbyte = input[pos++]; | ||
if (lenbyte & 0x80) { | ||
lenbyte -= 0x80; | ||
if (pos + lenbyte > inputlen) { | ||
return 0; | ||
} | ||
pos += lenbyte; | ||
} | ||
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/* Integer tag byte for R */ | ||
if (pos == inputlen || input[pos] != 0x02) { | ||
return 0; | ||
} | ||
pos++; | ||
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/* Integer length for R */ | ||
if (pos == inputlen) { | ||
return 0; | ||
} | ||
lenbyte = input[pos++]; | ||
if (lenbyte & 0x80) { | ||
lenbyte -= 0x80; | ||
if (pos + lenbyte > inputlen) { | ||
return 0; | ||
} | ||
while (lenbyte > 0 && input[pos] == 0) { | ||
pos++; | ||
lenbyte--; | ||
} | ||
if (lenbyte >= sizeof(size_t)) { | ||
return 0; | ||
} | ||
rlen = 0; | ||
while (lenbyte > 0) { | ||
rlen = (rlen << 8) + input[pos]; | ||
pos++; | ||
lenbyte--; | ||
} | ||
} else { | ||
rlen = lenbyte; | ||
} | ||
if (rlen > inputlen - pos) { | ||
return 0; | ||
} | ||
rpos = pos; | ||
pos += rlen; | ||
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/* Integer tag byte for S */ | ||
if (pos == inputlen || input[pos] != 0x02) { | ||
return 0; | ||
} | ||
pos++; | ||
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/* Integer length for S */ | ||
if (pos == inputlen) { | ||
return 0; | ||
} | ||
lenbyte = input[pos++]; | ||
if (lenbyte & 0x80) { | ||
lenbyte -= 0x80; | ||
if (pos + lenbyte > inputlen) { | ||
return 0; | ||
} | ||
while (lenbyte > 0 && input[pos] == 0) { | ||
pos++; | ||
lenbyte--; | ||
} | ||
if (lenbyte >= sizeof(size_t)) { | ||
return 0; | ||
} | ||
slen = 0; | ||
while (lenbyte > 0) { | ||
slen = (slen << 8) + input[pos]; | ||
pos++; | ||
lenbyte--; | ||
} | ||
} else { | ||
slen = lenbyte; | ||
} | ||
if (slen > inputlen - pos) { | ||
return 0; | ||
} | ||
spos = pos; | ||
pos += slen; | ||
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/* Ignore leading zeroes in R */ | ||
while (rlen > 0 && input[rpos] == 0) { | ||
rlen--; | ||
rpos++; | ||
} | ||
/* Copy R value */ | ||
if (rlen > 32) { | ||
overflow = 1; | ||
} else { | ||
memcpy(tmpsig + 32 - rlen, input + rpos, rlen); | ||
} | ||
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/* Ignore leading zeroes in S */ | ||
while (slen > 0 && input[spos] == 0) { | ||
slen--; | ||
spos++; | ||
} | ||
/* Copy S value */ | ||
if (slen > 32) { | ||
overflow = 1; | ||
} else { | ||
memcpy(tmpsig + 64 - slen, input + spos, slen); | ||
} | ||
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if (!overflow) { | ||
overflow = !secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig); | ||
} | ||
if (overflow) { | ||
memset(tmpsig, 0, 64); | ||
secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig); | ||
} | ||
return 1; | ||
} | ||
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