boringssl/crypto/evp/evp_asn1.c
David Benjamin 382bc29251 Defensively avoid assuming d2i functions don't advance on error.
Although the previous commit should ensure this doesn't happen, the
uint8_t** pattern is very error-prone and we're trying to avoid doing
much to the legacy ASN.1 stack. To that end, maintaining the strong
exception guarantee w.r.t. the input pointer-pointer is best effort and
we won't rely on it, so we needn't spend our time chasing down problems.

Change-Id: Ib78974eb94377fe0b0b379f57d9695dc81f344bb
Reviewed-on: https://boringssl-review.googlesource.com/5949
Reviewed-by: Adam Langley <agl@google.com>
2015-09-28 22:15:42 +00:00

180 lines
6.1 KiB
C

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <openssl/evp.h>
#include <openssl/asn1.h>
#include <openssl/err.h>
#include <openssl/obj.h>
#include <openssl/x509.h>
#include "internal.h"
EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **out, const uint8_t **inp,
long len) {
EVP_PKEY *ret;
if (out == NULL || *out == NULL) {
ret = EVP_PKEY_new();
if (ret == NULL) {
OPENSSL_PUT_ERROR(EVP, ERR_R_EVP_LIB);
return NULL;
}
} else {
ret = *out;
}
if (!EVP_PKEY_set_type(ret, type)) {
OPENSSL_PUT_ERROR(EVP, EVP_R_UNKNOWN_PUBLIC_KEY_TYPE);
goto err;
}
const uint8_t *in = *inp;
if (!ret->ameth->old_priv_decode ||
!ret->ameth->old_priv_decode(ret, &in, len)) {
if (ret->ameth->priv_decode) {
/* Reset |in| in case |old_priv_decode| advanced it on error. */
in = *inp;
PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &in, len);
if (!p8) {
goto err;
}
EVP_PKEY_free(ret);
ret = EVP_PKCS82PKEY(p8);
PKCS8_PRIV_KEY_INFO_free(p8);
if (ret == NULL) {
goto err;
}
} else {
OPENSSL_PUT_ERROR(EVP, ERR_R_ASN1_LIB);
goto err;
}
}
if (out != NULL) {
*out = ret;
}
*inp = in;
return ret;
err:
if (out == NULL || *out != ret) {
EVP_PKEY_free(ret);
}
return NULL;
}
EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **out, const uint8_t **inp, long len) {
STACK_OF(ASN1_TYPE) *inkey;
const uint8_t *p;
int keytype;
p = *inp;
/* Dirty trick: read in the ASN1 data into out STACK_OF(ASN1_TYPE):
* by analyzing it we can determine the passed structure: this
* assumes the input is surrounded by an ASN1 SEQUENCE. */
inkey = d2i_ASN1_SEQUENCE_ANY(NULL, &p, len);
/* Since we only need to discern "traditional format" RSA and DSA
* keys we can just count the elements. */
if (sk_ASN1_TYPE_num(inkey) == 6) {
keytype = EVP_PKEY_DSA;
} else if (sk_ASN1_TYPE_num(inkey) == 4) {
keytype = EVP_PKEY_EC;
} else if (sk_ASN1_TYPE_num(inkey) == 3) {
/* This seems to be PKCS8, not traditional format */
p = *inp;
PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, len);
EVP_PKEY *ret;
sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
if (!p8) {
OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
return NULL;
}
ret = EVP_PKCS82PKEY(p8);
PKCS8_PRIV_KEY_INFO_free(p8);
if (ret == NULL) {
return NULL;
}
*inp = p;
if (out) {
*out = ret;
}
return ret;
} else {
keytype = EVP_PKEY_RSA;
}
sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
return d2i_PrivateKey(keytype, out, inp, len);
}
int i2d_PublicKey(EVP_PKEY *key, uint8_t **outp) {
switch (key->type) {
case EVP_PKEY_RSA:
return i2d_RSAPublicKey(key->pkey.rsa, outp);
case EVP_PKEY_DSA:
return i2d_DSAPublicKey(key->pkey.dsa, outp);
case EVP_PKEY_EC:
return i2o_ECPublicKey(key->pkey.ec, outp);
default:
OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
return -1;
}
}