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Reimplement PKCS #3 DH parameter parsing with crypto/bytestring.

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Also add a test.

This is the last of the openssl/asn1.h includes from the directories that are
to be kept in the core libcrypto library. (What remains is to finish sorting
out the crypto/obj stuff. We'll also want to retain a decoupled version of the
PKCS#12 stuff.)

Functions that need to be audited for reuse:
i2d_DHparams

BUG=54

Change-Id: Ibef030a98d3a93ae26e8e56869f14858ec75601b
Reviewed-on: https://boringssl-review.googlesource.com/7900
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
This commit is contained in:
David Benjamin 2016-05-07 17:40:02 -04:00
parent e72df93461
commit 3473315415
4 changed files with 219 additions and 35 deletions
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114
crypto/dh/dh_asn1.c
View File

@ -55,30 +55,106 @@
#include <openssl/dh.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <assert.h>
#include <limits.h>
#include "internal.h"
#include <openssl/bn.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
/* Override the default free and new methods */
static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
void *exarg) {
if (operation == ASN1_OP_NEW_PRE) {
*pval = (ASN1_VALUE *)DH_new();
if (*pval) {
return 2;
}
#include "../bytestring/internal.h"
static int parse_integer(CBS *cbs, BIGNUM **out) {
assert(*out == NULL);
*out = BN_new();
if (*out == NULL) {
return 0;
}
return BN_parse_asn1_unsigned(cbs, *out);
}
static int marshal_integer(CBB *cbb, BIGNUM *bn) {
if (bn == NULL) {
/* A DH object may be missing some components. */
OPENSSL_PUT_ERROR(DH, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
return BN_marshal_asn1(cbb, bn);
}
DH *DH_parse_parameters(CBS *cbs) {
DH *ret = DH_new();
if (ret == NULL) {
return NULL;
}
CBS child;
if (!CBS_get_asn1(cbs, &child, CBS_ASN1_SEQUENCE) ||
!parse_integer(&child, &ret->p) ||
!parse_integer(&child, &ret->g)) {
goto err;
}
uint64_t priv_length;
if (CBS_len(&child) != 0) {
if (!CBS_get_asn1_uint64(&child, &priv_length) ||
priv_length > UINT_MAX) {
goto err;
}
ret->priv_length = (unsigned)priv_length;
}
if (CBS_len(&child) != 0) {
goto err;
}
return ret;
err:
OPENSSL_PUT_ERROR(DH, DH_R_DECODE_ERROR);
DH_free(ret);
return NULL;
}
int DH_marshal_parameters(CBB *cbb, const DH *dh) {
CBB child;
if (!CBB_add_asn1(cbb, &child, CBS_ASN1_SEQUENCE) ||
!marshal_integer(&child, dh->p) ||
!marshal_integer(&child, dh->g) ||
(dh->priv_length != 0 &&
!CBB_add_asn1_uint64(&child, dh->priv_length)) ||
!CBB_flush(cbb)) {
OPENSSL_PUT_ERROR(DH, DH_R_ENCODE_ERROR);
return 0;
} else if (operation == ASN1_OP_FREE_PRE) {
DH_free((DH *)*pval);
*pval = NULL;
return 2;
}
return 1;
}
ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
ASN1_SIMPLE(DH, p, BIGNUM), ASN1_SIMPLE(DH, g, BIGNUM),
ASN1_OPT(DH, priv_length, ZLONG)} ASN1_SEQUENCE_END_cb(DH, DHparams);
DH *d2i_DHparams(DH **out, const uint8_t **inp, long len) {
if (len < 0) {
return NULL;
}
CBS cbs;
CBS_init(&cbs, *inp, (size_t)len);
DH *ret = DH_parse_parameters(&cbs);
if (ret == NULL) {
return NULL;
}
if (out != NULL) {
DH_free(*out);
*out = ret;
}
*inp = CBS_data(&cbs);
return ret;
}
IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DH, DHparams, DHparams)
int i2d_DHparams(const DH *in, uint8_t **outp) {
CBB cbb;
if (!CBB_init(&cbb, 0) ||
!DH_marshal_parameters(&cbb, in)) {
CBB_cleanup(&cbb);
return -1;
}
return CBB_finish_i2d(&cbb, outp);
}

93
crypto/dh/dh_test.cc
View File

@ -62,6 +62,7 @@
#include <vector>
#include <openssl/bn.h>
#include <openssl/bytestring.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/mem.h>
@ -73,13 +74,15 @@
static bool RunBasicTests();
static bool RunRFC5114Tests();
static bool TestBadY();
static bool TestASN1();
int main(int argc, char *argv[]) {
CRYPTO_library_init();
if (!RunBasicTests() ||
!RunRFC5114Tests() ||
!TestBadY()) {
!TestBadY() ||
!TestASN1()) {
ERR_print_errors_fp(stderr);
return 1;
}
@ -533,3 +536,91 @@ static bool TestBadY() {
return true;
}
static bool BIGNUMEqualsHex(const BIGNUM *bn, const char *hex) {
BIGNUM *hex_bn = NULL;
if (!BN_hex2bn(&hex_bn, hex)) {
return false;
}
ScopedBIGNUM free_hex_bn(hex_bn);
return BN_cmp(bn, hex_bn) == 0;
}
static bool TestASN1() {
// kParams are a set of Diffie-Hellman parameters generated with
// openssl dhparam 256
static const uint8_t kParams[] = {
0x30, 0x26, 0x02, 0x21, 0x00, 0xd7, 0x20, 0x34, 0xa3, 0x27,
0x4f, 0xdf, 0xbf, 0x04, 0xfd, 0x24, 0x68, 0x25, 0xb6, 0x56,
0xd8, 0xab, 0x2a, 0x41, 0x2d, 0x74, 0x0a, 0x52, 0x08, 0x7c,
0x40, 0x71, 0x4e, 0xd2, 0x57, 0x93, 0x13, 0x02, 0x01, 0x02,
};
CBS cbs;
CBS_init(&cbs, kParams, sizeof(kParams));
ScopedDH dh(DH_parse_parameters(&cbs));
if (!dh || CBS_len(&cbs) != 0 ||
!BIGNUMEqualsHex(
dh->p,
"d72034a3274fdfbf04fd246825b656d8ab2a412d740a52087c40714ed2579313") ||
!BIGNUMEqualsHex(dh->g, "2") || dh->priv_length != 0) {
return false;
}
ScopedCBB cbb;
uint8_t *der;
size_t der_len;
if (!CBB_init(cbb.get(), 0) ||
!DH_marshal_parameters(cbb.get(), dh.get()) ||
!CBB_finish(cbb.get(), &der, &der_len)) {
return false;
}
ScopedOpenSSLBytes free_der(der);
if (der_len != sizeof(kParams) || memcmp(der, kParams, der_len) != 0) {
return false;
}
// kParamsDSA are a set of Diffie-Hellman parameters generated with
// openssl dhparam 256 -dsaparam
static const uint8_t kParamsDSA[] = {
0x30, 0x81, 0x89, 0x02, 0x41, 0x00, 0x93, 0xf3, 0xc1, 0x18, 0x01, 0xe6,
0x62, 0xb6, 0xd1, 0x46, 0x9a, 0x2c, 0x72, 0xea, 0x31, 0xd9, 0x18, 0x10,
0x30, 0x28, 0x63, 0xe2, 0x34, 0x7d, 0x80, 0xca, 0xee, 0x82, 0x2b, 0x19,
0x3c, 0x19, 0xbb, 0x42, 0x83, 0x02, 0x70, 0xdd, 0xdb, 0x8c, 0x03, 0xab,
0xe9, 0x9c, 0xc4, 0x00, 0x4d, 0x70, 0x5f, 0x52, 0x03, 0x31, 0x2c, 0xa4,
0x67, 0x34, 0x51, 0x95, 0x2a, 0xac, 0x11, 0xe2, 0x6a, 0x55, 0x02, 0x40,
0x44, 0xc8, 0x10, 0x53, 0x44, 0x32, 0x31, 0x63, 0xd8, 0xd1, 0x8c, 0x75,
0xc8, 0x98, 0x53, 0x3b, 0x5b, 0x4a, 0x2a, 0x0a, 0x09, 0xe7, 0xd0, 0x3c,
0x53, 0x72, 0xa8, 0x6b, 0x70, 0x41, 0x9c, 0x26, 0x71, 0x44, 0xfc, 0x7f,
0x08, 0x75, 0xe1, 0x02, 0xab, 0x74, 0x41, 0xe8, 0x2a, 0x3d, 0x3c, 0x26,
0x33, 0x09, 0xe4, 0x8b, 0xb4, 0x41, 0xec, 0xa6, 0xa8, 0xba, 0x1a, 0x07,
0x8a, 0x77, 0xf5, 0x5f, 0x02, 0x02, 0x00, 0xa0,
};
CBS_init(&cbs, kParamsDSA, sizeof(kParamsDSA));
dh.reset(DH_parse_parameters(&cbs));
if (!dh || CBS_len(&cbs) != 0 ||
!BIGNUMEqualsHex(dh->p,
"93f3c11801e662b6d1469a2c72ea31d91810302863e2347d80caee8"
"22b193c19bb42830270dddb8c03abe99cc4004d705f5203312ca467"
"3451952aac11e26a55") ||
!BIGNUMEqualsHex(dh->g,
"44c8105344323163d8d18c75c898533b5b4a2a0a09e7d03c5372a86"
"b70419c267144fc7f0875e102ab7441e82a3d3c263309e48bb441ec"
"a6a8ba1a078a77f55f") ||
dh->priv_length != 160) {
return false;
}
if (!CBB_init(cbb.get(), 0) ||
!DH_marshal_parameters(cbb.get(), dh.get()) ||
!CBB_finish(cbb.get(), &der, &der_len)) {
return false;
}
ScopedOpenSSLBytes free_der2(der);
if (der_len != sizeof(kParamsDSA) || memcmp(der, kParamsDSA, der_len) != 0) {
return false;
}
return true;
}

2
crypto/err/dh.errordata
View File

@ -1,4 +1,6 @@
DH,100,BAD_GENERATOR
DH,104,DECODE_ERROR
DH,105,ENCODE_ERROR
DH,101,INVALID_PUBKEY
DH,102,MODULUS_TOO_LARGE
DH,103,NO_PRIVATE_VALUE

45
include/openssl/dh.h
View File

@ -174,22 +174,15 @@ OPENSSL_EXPORT DH *DHparams_dup(const DH *dh);
/* ASN.1 functions. */
/* d2i_DHparams parses an ASN.1, DER encoded Diffie-Hellman parameters
* structure from |len| bytes at |*inp|. If |ret| is not NULL then, on exit, a
* pointer to the result is in |*ret|. If |*ret| is already non-NULL on entry
* then the result is written directly into |*ret|, otherwise a fresh |DH| is
* allocated. However, one should not depend on writing into |*ret| because
* this behaviour is likely to change in the future.
*
* On successful exit, |*inp| is advanced past the DER structure. It
* returns the result or NULL on error. */
OPENSSL_EXPORT DH *d2i_DHparams(DH **ret, const unsigned char **inp, long len);
/* DH_parse_parameters decodes a DER-encoded DHParameter structure (PKCS #3)
* from |cbs| and advances |cbs|. It returns a newly-allocated |DH| or NULL on
* error. */
OPENSSL_EXPORT DH *DH_parse_parameters(CBS *cbs);
/* i2d_DHparams marshals |in| to an ASN.1, DER structure. If |outp| is not NULL
* then the result is written to |*outp| and |*outp| is advanced just past the
* output. It returns the number of bytes in the result, whether written or
* not, or a negative value on error. */
OPENSSL_EXPORT int i2d_DHparams(const DH *in, unsigned char **outp);
/* DH_marshal_parameters marshals |dh| as a DER-encoded DHParameter structure
* (PKCS #3) and appends the result to |cbb|. It returns one on success and zero
* on error. */
OPENSSL_EXPORT int DH_marshal_parameters(CBB *cbb, const DH *dh);
/* ex_data functions.
@ -213,6 +206,26 @@ OPENSSL_EXPORT DH *DH_generate_parameters(int prime_len, int generator,
void (*callback)(int, int, void *),
void *cb_arg);
/* d2i_DHparams parses an ASN.1, DER encoded Diffie-Hellman parameters structure
* from |len| bytes at |*inp|. If |ret| is not NULL then, on exit, a pointer to
* the result is in |*ret|. Note that, even if |*ret| is already non-NULL on
* entry, it will not be written to. Rather, a fresh |DH| is allocated and the
* previous one is freed.
*
* On successful exit, |*inp| is advanced past the DER structure. It
* returns the result or NULL on error.
*
* Use |DH_parse_parameters| instead. */
OPENSSL_EXPORT DH *d2i_DHparams(DH **ret, const unsigned char **inp, long len);
/* i2d_DHparams marshals |in| to an ASN.1, DER structure. If |outp| is not NULL
* then the result is written to |*outp| and |*outp| is advanced just past the
* output. It returns the number of bytes in the result, whether written or
* not, or a negative value on error.
*
* Use |DH_marshal_parameters| instead. */
OPENSSL_EXPORT int i2d_DHparams(const DH *in, unsigned char **outp);
struct dh_st {
BIGNUM *p;
@ -248,5 +261,7 @@ struct dh_st {
#define DH_R_INVALID_PUBKEY 101
#define DH_R_MODULUS_TOO_LARGE 102
#define DH_R_NO_PRIVATE_VALUE 103
#define DH_R_DECODE_ERROR 104
#define DH_R_ENCODE_ERROR 105
#endif /* OPENSSL_HEADER_DH_H */