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/* $OpenBSD: sshbuf-getput-crypto.c,v 1.5 2016/01/12 23:42:54 djm Exp $ */ |
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/* |
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* Copyright (c) 2011 Damien Miller |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <openssl/bn.h> |
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#include <openssl/ec.h> |
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#include "ssherr.h" |
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#define SSHBUF_INTERNAL |
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#include "sshbuf.h" |
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int |
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sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v) |
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{ |
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const u_char *d; |
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size_t len; |
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int r; |
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if ((r = sshbuf_get_bignum2_bytes_direct(buf, &d, &len)) != 0) |
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return r; |
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if (v != NULL && BN_bin2bn(d, len, v) == NULL) |
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return SSH_ERR_ALLOC_FAIL; |
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return 0; |
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} |
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int |
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sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v) |
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{ |
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const u_char *d = sshbuf_ptr(buf); |
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u_int16_t len_bits; |
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size_t len_bytes; |
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/* Length in bits */ |
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if (sshbuf_len(buf) < 2) |
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return SSH_ERR_MESSAGE_INCOMPLETE; |
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len_bits = PEEK_U16(d); |
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len_bytes = (len_bits + 7) >> 3; |
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if (len_bytes > SSHBUF_MAX_BIGNUM) |
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return SSH_ERR_BIGNUM_TOO_LARGE; |
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if (sshbuf_len(buf) < 2 + len_bytes) |
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return SSH_ERR_MESSAGE_INCOMPLETE; |
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if (v != NULL && BN_bin2bn(d + 2, len_bytes, v) == NULL) |
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return SSH_ERR_ALLOC_FAIL; |
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if (sshbuf_consume(buf, 2 + len_bytes) != 0) { |
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SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR")); |
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SSHBUF_ABORT(); |
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return SSH_ERR_INTERNAL_ERROR; |
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} |
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return 0; |
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} |
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static int |
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get_ec(const u_char *d, size_t len, EC_POINT *v, const EC_GROUP *g) |
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{ |
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/* Refuse overlong bignums */ |
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if (len == 0 || len > SSHBUF_MAX_ECPOINT) |
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return SSH_ERR_ECPOINT_TOO_LARGE; |
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/* Only handle uncompressed points */ |
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if (*d != POINT_CONVERSION_UNCOMPRESSED) |
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return SSH_ERR_INVALID_FORMAT; |
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if (v != NULL && EC_POINT_oct2point(g, v, d, len, NULL) != 1) |
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return SSH_ERR_INVALID_FORMAT; /* XXX assumption */ |
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return 0; |
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} |
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int |
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sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g) |
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{ |
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const u_char *d; |
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size_t len; |
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int r; |
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if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0) |
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return r; |
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if ((r = get_ec(d, len, v, g)) != 0) |
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return r; |
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/* Skip string */ |
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if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) { |
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/* Shouldn't happen */ |
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SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR")); |
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SSHBUF_ABORT(); |
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return SSH_ERR_INTERNAL_ERROR; |
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} |
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return 0; |
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} |
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int |
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sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v) |
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{ |
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EC_POINT *pt = EC_POINT_new(EC_KEY_get0_group(v)); |
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int r; |
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const u_char *d; |
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size_t len; |
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if (pt == NULL) { |
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SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL")); |
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return SSH_ERR_ALLOC_FAIL; |
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} |
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if ((r = sshbuf_peek_string_direct(buf, &d, &len)) < 0) { |
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EC_POINT_free(pt); |
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return r; |
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} |
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if ((r = get_ec(d, len, pt, EC_KEY_get0_group(v))) != 0) { |
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EC_POINT_free(pt); |
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return r; |
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} |
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if (EC_KEY_set_public_key(v, pt) != 1) { |
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EC_POINT_free(pt); |
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return SSH_ERR_ALLOC_FAIL; /* XXX assumption */ |
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} |
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EC_POINT_free(pt); |
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/* Skip string */ |
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if (sshbuf_get_string_direct(buf, NULL, NULL) != 0) { |
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/* Shouldn't happen */ |
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SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR")); |
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SSHBUF_ABORT(); |
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return SSH_ERR_INTERNAL_ERROR; |
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} |
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return 0; |
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} |
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int |
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sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v) |
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{ |
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u_char d[SSHBUF_MAX_BIGNUM + 1]; |
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int len = BN_num_bytes(v), prepend = 0, r; |
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if (len < 0 || len > SSHBUF_MAX_BIGNUM) |
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return SSH_ERR_INVALID_ARGUMENT; |
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*d = '\0'; |
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if (BN_bn2bin(v, d + 1) != len) |
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return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */ |
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/* If MSB is set, prepend a \0 */ |
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if (len > 0 && (d[1] & 0x80) != 0) |
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prepend = 1; |
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if ((r = sshbuf_put_string(buf, d + 1 - prepend, len + prepend)) < 0) { |
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explicit_bzero(d, sizeof(d)); |
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return r; |
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} |
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explicit_bzero(d, sizeof(d)); |
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return 0; |
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} |
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int |
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sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v) |
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{ |
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int r, len_bits = BN_num_bits(v); |
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size_t len_bytes = (len_bits + 7) / 8; |
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u_char d[SSHBUF_MAX_BIGNUM], *dp; |
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if (len_bits < 0 || len_bytes > SSHBUF_MAX_BIGNUM) |
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return SSH_ERR_INVALID_ARGUMENT; |
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if (BN_bn2bin(v, d) != (int)len_bytes) |
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return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */ |
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if ((r = sshbuf_reserve(buf, len_bytes + 2, &dp)) < 0) { |
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explicit_bzero(d, sizeof(d)); |
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return r; |
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} |
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POKE_U16(dp, len_bits); |
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if (len_bytes != 0) |
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memcpy(dp + 2, d, len_bytes); |
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explicit_bzero(d, sizeof(d)); |
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return 0; |
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} |
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int |
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sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g) |
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{ |
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u_char d[SSHBUF_MAX_ECPOINT]; |
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BN_CTX *bn_ctx; |
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size_t len; |
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int ret; |
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if ((bn_ctx = BN_CTX_new()) == NULL) |
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return SSH_ERR_ALLOC_FAIL; |
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if ((len = EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED, |
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NULL, 0, bn_ctx)) > SSHBUF_MAX_ECPOINT) { |
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BN_CTX_free(bn_ctx); |
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return SSH_ERR_INVALID_ARGUMENT; |
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} |
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if (EC_POINT_point2oct(g, v, POINT_CONVERSION_UNCOMPRESSED, |
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d, len, bn_ctx) != len) { |
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BN_CTX_free(bn_ctx); |
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return SSH_ERR_INTERNAL_ERROR; /* Shouldn't happen */ |
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} |
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BN_CTX_free(bn_ctx); |
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ret = sshbuf_put_string(buf, d, len); |
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explicit_bzero(d, len); |
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return ret; |
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} |
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int |
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sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v) |
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{ |
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return sshbuf_put_ec(buf, EC_KEY_get0_public_key(v), |
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EC_KEY_get0_group(v)); |
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} |
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