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[tls] Use our own ASN.1 routines for certificate parsing 

Use our own, more robust, ASN.1 parsing routines to extract the RSA
public key from a server certificate.  Remove the now-unused AXTLS
ASN.1 parser.
This commit is contained in:
Michael Brown 2009-02-10 17:37:24 +00:00
parent 5a99c586cf
commit 8e960eb67c
8 changed files with 353 additions and 953 deletions
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31
src/crypto/asn1.c
View File

@ -32,7 +32,7 @@
*
* @v cursor ASN.1 object cursor
* @v type Expected type
* @ret len Length of object body, or -1 on error
* @ret len Length of object body, or negative error
*
* The object cursor will be updated to point to the start of the
* object body (i.e. the first byte following the length byte(s)), and
@ -44,29 +44,32 @@
* the cursor will be invalidated and a negative value will be
* returned.
*/
static int asn1_start_object ( struct asn1_cursor *cursor,
static int asn1_start ( struct asn1_cursor *cursor,
unsigned int type ) {
unsigned int len_len;
unsigned int len;
int rc;
/* Sanity check */
if ( cursor->len < 2 /* Tag byte and first length byte */ ) {
if ( cursor->len )
DBGC ( cursor, "ASN1 %p too short\n", cursor );
rc = -EINVAL;
goto notfound;
}
/* Check the tag byte */
if ( cursor->data[0] != type ) {
if ( *( ( uint8_t * ) cursor->data ) != type ) {
DBGC ( cursor, "ASN1 %p type mismatch (expected %d, got %d)\n",
cursor, type, cursor->data[0] );
cursor, type, *( ( uint8_t * ) cursor->data ) );
rc = -ENXIO;
goto notfound;
}
cursor->data++;
cursor->len--;
/* Extract length of the length field and sanity check */
len_len = cursor->data[0];
len_len = *( ( uint8_t * ) cursor->data );
if ( len_len & 0x80 ) {
len_len = ( len_len & 0x7f );
cursor->data++;
@ -77,19 +80,21 @@ static int asn1_start_object ( struct asn1_cursor *cursor,
if ( cursor->len < len_len ) {
DBGC ( cursor, "ASN1 %p bad length field length %d (max "
"%zd)\n", cursor, len_len, cursor->len );
rc = -EINVAL;
goto notfound;
}
/* Extract the length and sanity check */
for ( len = 0 ; len_len ; len_len-- ) {
len <<= 8;
len |= cursor->data[0];
len |= *( ( uint8_t * ) cursor->data );
cursor->data++;
cursor->len--;
}
if ( cursor->len < len ) {
DBGC ( cursor, "ASN1 %p bad length %d (max %zd)\n",
cursor, len, cursor->len );
rc = -EINVAL;
goto notfound;
}
@ -98,7 +103,7 @@ static int asn1_start_object ( struct asn1_cursor *cursor,
notfound:
cursor->data = NULL;
cursor->len = 0;
return -1;
return rc;
}
/**
@ -112,12 +117,12 @@ static int asn1_start_object ( struct asn1_cursor *cursor,
* current ASN.1 object. If any error occurs, the object cursor will
* be invalidated.
*/
int asn1_enter_object ( struct asn1_cursor *cursor, unsigned int type ) {
int asn1_enter ( struct asn1_cursor *cursor, unsigned int type ) {
int len;
len = asn1_start_object ( cursor, type );
len = asn1_start ( cursor, type );
if ( len < 0 )
return -ENOENT;
return len;
cursor->len = len;
DBGC ( cursor, "ASN1 %p entered object type %02x (len %x)\n",
@ -137,12 +142,12 @@ int asn1_enter_object ( struct asn1_cursor *cursor, unsigned int type ) {
* object. If any error occurs, the object cursor will be
* invalidated.
*/
int asn1_skip_object ( struct asn1_cursor *cursor, unsigned int type ) {
int asn1_skip ( struct asn1_cursor *cursor, unsigned int type ) {
int len;
len = asn1_start_object ( cursor, type );
len = asn1_start ( cursor, type );
if ( len < 0 )
return -ENOENT;
return len;
cursor->data += len;
cursor->len -= len;

867
src/crypto/axtls/axtls_asn1.c
View File

@ -1,867 +0,0 @@
/*
* Copyright(C) 2006 Cameron Rich
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file asn1.c
*
* Some primitive asn methods for extraction rsa modulus information. It also
* is used for retrieving information from X.509 certificates.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "crypto.h"
#define SIG_OID_PREFIX_SIZE 8
#define SIG_TYPE_MD2 0x02
#define SIG_TYPE_MD5 0x04
#define SIG_TYPE_SHA1 0x05
/* Must be an RSA algorithm with either SHA1 or MD5 for verifying to work */
static const uint8_t sig_oid_prefix[SIG_OID_PREFIX_SIZE] =
{
0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01
};
/* CN, O, OU */
static const uint8_t g_dn_types[] = { 3, 10, 11 };
static int get_asn1_length(const uint8_t *buf, int *offset)
{
int len, i;
if (!(buf[*offset] & 0x80)) /* short form */
{
len = buf[(*offset)++];
}
else /* long form */
{
int length_bytes = buf[(*offset)++]&0x7f;
len = 0;
for (i = 0; i < length_bytes; i++)
{
len <<= 8;
len += buf[(*offset)++];
}
}
return len;
}
/**
* Skip the ASN1.1 object type and its length. Get ready to read the object's
* data.
*/
int asn1_next_obj(const uint8_t *buf, int *offset, int obj_type)
{
if (buf[*offset] != obj_type)
return X509_NOT_OK;
(*offset)++;
return get_asn1_length(buf, offset);
}
/**
* Skip over an ASN.1 object type completely. Get ready to read the next
* object.
*/
int asn1_skip_obj(const uint8_t *buf, int *offset, int obj_type)
{
int len;
if (buf[*offset] != obj_type)
return X509_NOT_OK;
(*offset)++;
len = get_asn1_length(buf, offset);
*offset += len;
return 0;
}
/**
* Read an integer value for ASN.1 data
* Note: This function allocates memory which must be freed by the user.
*/
int asn1_get_int(const uint8_t *buf, int *offset, uint8_t **object)
{
int len;
if ((len = asn1_next_obj(buf, offset, ASN1_INTEGER)) < 0)
goto end_int_array;
*object = (uint8_t *)malloc(len);
memcpy(*object, &buf[*offset], len);
*offset += len;
end_int_array:
return len;
}
#if 0
/**
* Get all the RSA private key specifics from an ASN.1 encoded file
*/
int asn1_get_private_key(const uint8_t *buf, int len, RSA_CTX **rsa_ctx)
{
int offset = 7;
uint8_t *modulus, *priv_exp, *pub_exp;
int mod_len, priv_len, pub_len;
#ifdef CONFIG_BIGINT_CRT
uint8_t *p, *q, *dP, *dQ, *qInv;
int p_len, q_len, dP_len, dQ_len, qInv_len;
#endif
/* not in der format */
if (buf[0] != ASN1_SEQUENCE) /* basic sanity check */
{
#ifdef CONFIG_SSL_FULL_MODE
printf("Error: This is not a valid ASN.1 file\n");
#endif
return X509_INVALID_PRIV_KEY;
}
/* initialise the RNG */
RNG_initialize(buf, len);
mod_len = asn1_get_int(buf, &offset, &modulus);
pub_len = asn1_get_int(buf, &offset, &pub_exp);
priv_len = asn1_get_int(buf, &offset, &priv_exp);
if (mod_len <= 0 || pub_len <= 0 || priv_len <= 0)
return X509_INVALID_PRIV_KEY;
#ifdef CONFIG_BIGINT_CRT
p_len = asn1_get_int(buf, &offset, &p);
q_len = asn1_get_int(buf, &offset, &q);
dP_len = asn1_get_int(buf, &offset, &dP);
dQ_len = asn1_get_int(buf, &offset, &dQ);
qInv_len = asn1_get_int(buf, &offset, &qInv);
if (p_len <= 0 || q_len <= 0 || dP_len <= 0 || dQ_len <= 0 || qInv_len <= 0)
return X509_INVALID_PRIV_KEY;
RSA_priv_key_new(rsa_ctx,
modulus, mod_len, pub_exp, pub_len, priv_exp, priv_len,
p, p_len, q, p_len, dP, dP_len, dQ, dQ_len, qInv, qInv_len);
free(p);
free(q);
free(dP);
free(dQ);
free(qInv);
#else
RSA_priv_key_new(rsa_ctx,
modulus, mod_len, pub_exp, pub_len, priv_exp, priv_len);
#endif
free(modulus);
free(priv_exp);
free(pub_exp);
return X509_OK;
}
/**
* Get the time of a certificate. Ignore hours/minutes/seconds.
*/
static int asn1_get_utc_time(const uint8_t *buf, int *offset, time_t *t)
{
int ret = X509_NOT_OK, len, t_offset;
struct tm tm;
if (buf[(*offset)++] != ASN1_UTC_TIME)
goto end_utc_time;
len = get_asn1_length(buf, offset);
t_offset = *offset;
memset(&tm, 0, sizeof(struct tm));
tm.tm_year = (buf[t_offset] - '0')*10 + (buf[t_offset+1] - '0');
if (tm.tm_year <= 50) /* 1951-2050 thing */
{
tm.tm_year += 100;
}
tm.tm_mon = (buf[t_offset+2] - '0')*10 + (buf[t_offset+3] - '0') - 1;
tm.tm_mday = (buf[t_offset+4] - '0')*10 + (buf[t_offset+5] - '0');
*t = mktime(&tm);
*offset += len;
ret = X509_OK;
end_utc_time:
return ret;
}
/**
* Get the version type of a certificate (which we don't actually care about)
*/
static int asn1_version(const uint8_t *cert, int *offset, X509_CTX *x509_ctx)
{
int ret = X509_NOT_OK;
(*offset) += 2; /* get past explicit tag */
if (asn1_skip_obj(cert, offset, ASN1_INTEGER))
goto end_version;
ret = X509_OK;
end_version:
return ret;
}
/**
* Retrieve the notbefore and notafter certificate times.
*/
static int asn1_validity(const uint8_t *cert, int *offset, X509_CTX *x509_ctx)
{
return (asn1_next_obj(cert, offset, ASN1_SEQUENCE) < 0 ||
asn1_get_utc_time(cert, offset, &x509_ctx->not_before) ||
asn1_get_utc_time(cert, offset, &x509_ctx->not_after));
}
/**
* Get the components of a distinguished name
*/
static int asn1_get_oid_x520(const uint8_t *buf, int *offset)
{
int dn_type = 0;
int len;
if ((len = asn1_next_obj(buf, offset, ASN1_OID)) < 0)
goto end_oid;
/* expect a sequence of 2.5.4.[x] where x is a one of distinguished name
components we are interested in. */
if (len == 3 && buf[(*offset)++] == 0x55 && buf[(*offset)++] == 0x04)
dn_type = buf[(*offset)++];
else
{
*offset += len; /* skip over it */
}
end_oid:
return dn_type;
}
/**
* Obtain an ASN.1 printable string type.
*/
static int asn1_get_printable_str(const uint8_t *buf, int *offset, char **str)
{
int len = X509_NOT_OK;
/* some certs have this awful crud in them for some reason */
if (buf[*offset] != ASN1_PRINTABLE_STR &&
buf[*offset] != ASN1_TELETEX_STR && buf[*offset] != ASN1_IA5_STR)
goto end_pnt_str;
(*offset)++;
len = get_asn1_length(buf, offset);
*str = (char *)malloc(len+1); /* allow for null */
memcpy(*str, &buf[*offset], len);
(*str)[len] = 0; /* null terminate */
*offset += len;
end_pnt_str:
return len;
}
/**
* Get the subject name (or the issuer) of a certificate.
*/
static int asn1_name(const uint8_t *cert, int *offset, char *dn[])
{
int ret = X509_NOT_OK;
int dn_type;
char *tmp = NULL;
if (asn1_next_obj(cert, offset, ASN1_SEQUENCE) < 0)
goto end_name;
while (asn1_next_obj(cert, offset, ASN1_SET) >= 0)
{
int i, found = 0;
if (asn1_next_obj(cert, offset, ASN1_SEQUENCE) < 0 ||
(dn_type = asn1_get_oid_x520(cert, offset)) < 0)
goto end_name;
if (asn1_get_printable_str(cert, offset, &tmp) < 0)
{
free(tmp);
goto end_name;
}
/* find the distinguished named type */
for (i = 0; i < X509_NUM_DN_TYPES; i++)
{
if (dn_type == g_dn_types[i])
{
if (dn[i] == NULL)
{
dn[i] = tmp;
found = 1;
break;
}
}
}
if (found == 0) /* not found so get rid of it */
{
free(tmp);
}
}
ret = X509_OK;
end_name:
return ret;
}
/**
* Read the modulus and public exponent of a certificate.
*/
static int asn1_public_key(const uint8_t *cert, int *offset, X509_CTX *x509_ctx)
{
int ret = X509_NOT_OK, mod_len, pub_len;
uint8_t *modulus, *pub_exp;
if (asn1_next_obj(cert, offset, ASN1_SEQUENCE) < 0 ||
asn1_skip_obj(cert, offset, ASN1_SEQUENCE) ||
asn1_next_obj(cert, offset, ASN1_BIT_STRING) < 0)
goto end_pub_key;
(*offset)++;
if (asn1_next_obj(cert, offset, ASN1_SEQUENCE) < 0)
goto end_pub_key;
mod_len = asn1_get_int(cert, offset, &modulus);
pub_len = asn1_get_int(cert, offset, &pub_exp);
RSA_pub_key_new(&x509_ctx->rsa_ctx, modulus, mod_len, pub_exp, pub_len);
free(modulus);
free(pub_exp);
ret = X509_OK;
end_pub_key:
return ret;
}
#ifdef CONFIG_SSL_CERT_VERIFICATION
/**
* Read the signature of the certificate.
*/
static int asn1_signature(const uint8_t *cert, int *offset, X509_CTX *x509_ctx)
{
int ret = X509_NOT_OK;
if (cert[(*offset)++] != ASN1_BIT_STRING)
goto end_sig;
x509_ctx->sig_len = get_asn1_length(cert, offset);
x509_ctx->signature = (uint8_t *)malloc(x509_ctx->sig_len);
memcpy(x509_ctx->signature, &cert[*offset], x509_ctx->sig_len);
*offset += x509_ctx->sig_len;
ret = X509_OK;
end_sig:
return ret;
}
/*
* Compare 2 distinguished name components for equality
* @return 0 if a match
*/
static int asn1_compare_dn_comp(const char *dn1, const char *dn2)
{
int ret = 1;
if ((dn1 && dn2 == NULL) || (dn1 == NULL && dn2)) goto err_no_match;
ret = (dn1 && dn2) ? strcmp(dn1, dn2) : 0;
err_no_match:
return ret;
}
/**
* Clean up all of the CA certificates.
*/
void remove_ca_certs(CA_CERT_CTX *ca_cert_ctx)
{
int i = 0;
while (i < CONFIG_X509_MAX_CA_CERTS && ca_cert_ctx->cert[i])
{
x509_free(ca_cert_ctx->cert[i]);
ca_cert_ctx->cert[i++] = NULL;
}
free(ca_cert_ctx);
}
/*
* Compare 2 distinguished names for equality
* @return 0 if a match
*/
static int asn1_compare_dn(char * const dn1[], char * const dn2[])
{
int i;
for (i = 0; i < X509_NUM_DN_TYPES; i++)
{
if (asn1_compare_dn_comp(dn1[i], dn2[i]))
{
return 1;
}
}
return 0; /* all good */
}
/**
* Retrieve the signature from a certificate.
*/
const uint8_t *x509_get_signature(const uint8_t *asn1_sig, int *len)
{
int offset = 0;
const uint8_t *ptr = NULL;
if (asn1_next_obj(asn1_sig, &offset, ASN1_SEQUENCE) < 0 ||
asn1_skip_obj(asn1_sig, &offset, ASN1_SEQUENCE))
goto end_get_sig;
if (asn1_sig[offset++] != ASN1_OCTET_STRING)
goto end_get_sig;
*len = get_asn1_length(asn1_sig, &offset);
ptr = &asn1_sig[offset]; /* all ok */
end_get_sig:
return ptr;
}
#endif
/**
* Read the signature type of the certificate. We only support RSA-MD5 and
* RSA-SHA1 signature types.
*/
static int asn1_signature_type(const uint8_t *cert,
int *offset, X509_CTX *x509_ctx)
{
int ret = X509_NOT_OK, len;
if (cert[(*offset)++] != ASN1_OID)
goto end_check_sig;
len = get_asn1_length(cert, offset);
if (memcmp(sig_oid_prefix, &cert[*offset], SIG_OID_PREFIX_SIZE))
goto end_check_sig; /* unrecognised cert type */
x509_ctx->sig_type = cert[*offset + SIG_OID_PREFIX_SIZE];
*offset += len;
if (asn1_skip_obj(cert, offset, ASN1_NULL))
goto end_check_sig;
ret = X509_OK;
end_check_sig:
return ret;
}
/**
* Construct a new x509 object.
* @return 0 if ok. < 0 if there was a problem.
*/
int x509_new(const uint8_t *cert, int *len, X509_CTX **ctx)
{
int begin_tbs, end_tbs;
int ret = X509_NOT_OK, offset = 0, cert_size = 0;
X509_CTX *x509_ctx;
BI_CTX *bi_ctx;
*ctx = (X509_CTX *)calloc(1, sizeof(X509_CTX));
x509_ctx = *ctx;
/* get the certificate size */
asn1_skip_obj(cert, &cert_size, ASN1_SEQUENCE);
if (asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0)
goto end_cert;
begin_tbs = offset; /* start of the tbs */
end_tbs = begin_tbs; /* work out the end of the tbs */
asn1_skip_obj(cert, &end_tbs, ASN1_SEQUENCE);
if (asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0)
goto end_cert;
if (cert[offset] == ASN1_EXPLICIT_TAG) /* optional version */
{
if (asn1_version(cert, &offset, x509_ctx))
goto end_cert;
}
if (asn1_skip_obj(cert, &offset, ASN1_INTEGER) || /* serial number */
asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0)
goto end_cert;
/* make sure the signature is ok */
if (asn1_signature_type(cert, &offset, x509_ctx))
{
ret = X509_VFY_ERROR_UNSUPPORTED_DIGEST;
goto end_cert;
}
if (asn1_name(cert, &offset, x509_ctx->ca_cert_dn) ||
asn1_validity(cert, &offset, x509_ctx) ||
asn1_name(cert, &offset, x509_ctx->cert_dn) ||
asn1_public_key(cert, &offset, x509_ctx))
goto end_cert;
bi_ctx = x509_ctx->rsa_ctx->bi_ctx;
#ifdef CONFIG_SSL_CERT_VERIFICATION /* only care if doing verification */
/* use the appropriate signature algorithm (either SHA1 or MD5) */
if (x509_ctx->sig_type == SIG_TYPE_MD5)
{
MD5_CTX md5_ctx;
uint8_t md5_dgst[MD5_SIZE];
MD5Init(&md5_ctx);
MD5Update(&md5_ctx, &cert[begin_tbs], end_tbs-begin_tbs);
MD5Final(&md5_ctx, md5_dgst);
x509_ctx->digest = bi_import(bi_ctx, md5_dgst, MD5_SIZE);
}
else if (x509_ctx->sig_type == SIG_TYPE_SHA1)
{
SHA1_CTX sha_ctx;
uint8_t sha_dgst[SHA1_SIZE];
SHA1Init(&sha_ctx);
SHA1Update(&sha_ctx, &cert[begin_tbs], end_tbs-begin_tbs);
SHA1Final(&sha_ctx, sha_dgst);
x509_ctx->digest = bi_import(bi_ctx, sha_dgst, SHA1_SIZE);
}
offset = end_tbs; /* skip the v3 data */
if (asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) ||
asn1_signature(cert, &offset, x509_ctx))
goto end_cert;
#endif
if (len)
{
*len = cert_size;
}
ret = X509_OK;
end_cert:
#ifdef CONFIG_SSL_FULL_MODE
if (ret)
{
printf("Error: Invalid X509 ASN.1 file\n");
}
#endif
return ret;
}
/**
* Free an X.509 object's resources.
*/
void x509_free(X509_CTX *x509_ctx)
{
X509_CTX *next;
int i;
if (x509_ctx == NULL) /* if already null, then don't bother */
return;
for (i = 0; i < X509_NUM_DN_TYPES; i++)
{
free(x509_ctx->ca_cert_dn[i]);
free(x509_ctx->cert_dn[i]);
}
free(x509_ctx->signature);
#ifdef CONFIG_SSL_CERT_VERIFICATION
if (x509_ctx->digest)
{
bi_free(x509_ctx->rsa_ctx->bi_ctx, x509_ctx->digest);
}
#endif
RSA_free(x509_ctx->rsa_ctx);
next = x509_ctx->next;
free(x509_ctx);
x509_free(next); /* clear the chain */
}
#ifdef CONFIG_SSL_CERT_VERIFICATION
/**
* Do some basic checks on the certificate chain.
*
* Certificate verification consists of a number of checks:
* - A root certificate exists in the certificate store.
* - The date of the certificate is after the start date.
* - The date of the certificate is before the finish date.
* - The certificate chain is valid.
* - That the certificate(s) are not self-signed.
* - The signature of the certificate is valid.
*/
int x509_verify(const CA_CERT_CTX *ca_cert_ctx, const X509_CTX *cert)
{
int ret = X509_OK, i = 0;
bigint *cert_sig;
X509_CTX *next_cert = NULL;
BI_CTX *ctx;
bigint *mod, *expn;
struct timeval tv;
int match_ca_cert = 0;
if (cert == NULL || ca_cert_ctx == NULL)
{
ret = X509_VFY_ERROR_NO_TRUSTED_CERT;
goto end_verify;
}
/* last cert in the chain - look for a trusted cert */
if (cert->next == NULL)
{
while (i < CONFIG_X509_MAX_CA_CERTS && ca_cert_ctx->cert[i])
{
if (asn1_compare_dn(cert->ca_cert_dn,
ca_cert_ctx->cert[i]->cert_dn) == 0)
{
match_ca_cert = 1;
break;
}
i++;
}
if (i < CONFIG_X509_MAX_CA_CERTS && ca_cert_ctx->cert[i])
{
next_cert = ca_cert_ctx->cert[i];
}
else /* trusted cert not found */
{
ret = X509_VFY_ERROR_NO_TRUSTED_CERT;
goto end_verify;
}
}
else
{
next_cert = cert->next;
}
gettimeofday(&tv, NULL);
/* check the not before date */
if (tv.tv_sec < cert->not_before)
{
ret = X509_VFY_ERROR_NOT_YET_VALID;
goto end_verify;
}
/* check the not after date */
if (tv.tv_sec > cert->not_after)
{
ret = X509_VFY_ERROR_EXPIRED;
goto end_verify;
}
/* check the chain integrity */
if (asn1_compare_dn(cert->ca_cert_dn, next_cert->cert_dn))
{
ret = X509_VFY_ERROR_INVALID_CHAIN;
goto end_verify;
}
/* check for self-signing */
if (!match_ca_cert && asn1_compare_dn(cert->ca_cert_dn, cert->cert_dn) == 0)
{
ret = X509_VFY_ERROR_SELF_SIGNED;
goto end_verify;
}
/* check the signature */
ctx = cert->rsa_ctx->bi_ctx;
mod = next_cert->rsa_ctx->m;
expn = next_cert->rsa_ctx->e;
cert_sig = RSA_sign_verify(ctx, cert->signature, cert->sig_len,
bi_clone(ctx, mod), bi_clone(ctx, expn));
if (cert_sig)
{
ret = cert->digest ? /* check the signature */
bi_compare(cert_sig, cert->digest) :
X509_VFY_ERROR_UNSUPPORTED_DIGEST;
bi_free(ctx, cert_sig);
if (ret)
goto end_verify;
}
else
{
ret = X509_VFY_ERROR_BAD_SIGNATURE;
goto end_verify;
}
/* go down the certificate chain using recursion. */
if (ret == 0 && cert->next)
{
ret = x509_verify(ca_cert_ctx, next_cert);
}
end_verify:
return ret;
}
#endif
#if defined (CONFIG_SSL_FULL_MODE)
/**
* Used for diagnostics.
*/
void x509_print(CA_CERT_CTX *ca_cert_ctx, const X509_CTX *cert)
{
if (cert == NULL)
return;
printf("---------------- CERT DEBUG ----------------\n");
printf("* CA Cert Distinguished Name\n");
if (cert->ca_cert_dn[X509_COMMON_NAME])
{
printf("Common Name (CN):\t%s\n", cert->ca_cert_dn[X509_COMMON_NAME]);
}
if (cert->ca_cert_dn[X509_ORGANIZATION])
{
printf("Organization (O):\t%s\n", cert->ca_cert_dn[X509_ORGANIZATION]);
}
if (cert->ca_cert_dn[X509_ORGANIZATIONAL_TYPE])
{
printf("Organizational Unit (OU): %s\n",
cert->ca_cert_dn[X509_ORGANIZATIONAL_TYPE]);
}
printf("* Cert Distinguished Name\n");
if (cert->cert_dn[X509_COMMON_NAME])
{
printf("Common Name (CN):\t%s\n", cert->cert_dn[X509_COMMON_NAME]);
}
if (cert->cert_dn[X509_ORGANIZATION])
{
printf("Organization (O):\t%s\n", cert->cert_dn[X509_ORGANIZATION]);
}
if (cert->cert_dn[X509_ORGANIZATIONAL_TYPE])
{
printf("Organizational Unit (OU): %s\n",
cert->cert_dn[X509_ORGANIZATIONAL_TYPE]);
}
printf("Not Before:\t\t%s", ctime(&cert->not_before));
printf("Not After:\t\t%s", ctime(&cert->not_after));
printf("RSA bitsize:\t\t%d\n", cert->rsa_ctx->num_octets*8);
printf("Sig Type:\t\t");
switch (cert->sig_type)
{
case SIG_TYPE_MD5:
printf("MD5\n");
break;
case SIG_TYPE_SHA1:
printf("SHA1\n");
break;
case SIG_TYPE_MD2:
printf("MD2\n");
break;
default:
printf("Unrecognized: %d\n", cert->sig_type);
break;
}
printf("Verify:\t\t\t");
if (ca_cert_ctx)
{
x509_display_error(x509_verify(ca_cert_ctx, cert));
}
printf("\n");
#if 0
print_blob("Signature", cert->signature, cert->sig_len);
bi_print("Modulus", cert->rsa_ctx->m);
bi_print("Pub Exp", cert->rsa_ctx->e);
#endif
if (ca_cert_ctx)
{
x509_print(ca_cert_ctx, cert->next);
}
}
void x509_display_error(int error)
{
switch (error)
{
case X509_NOT_OK:
printf("X509 not ok");
break;
case X509_VFY_ERROR_NO_TRUSTED_CERT:
printf("No trusted cert is available");
break;
case X509_VFY_ERROR_BAD_SIGNATURE:
printf("Bad signature");
break;
case X509_VFY_ERROR_NOT_YET_VALID:
printf("Cert is not yet valid");
break;
case X509_VFY_ERROR_EXPIRED:
printf("Cert has expired");
break;
case X509_VFY_ERROR_SELF_SIGNED:
printf("Cert is self-signed");
break;
case X509_VFY_ERROR_INVALID_CHAIN:
printf("Chain is invalid (check order of certs)");
break;
case X509_VFY_ERROR_UNSUPPORTED_DIGEST:
printf("Unsupported digest");
break;
case X509_INVALID_PRIV_KEY:
printf("Invalid private key");
break;
}
}
#endif /* CONFIG_SSL_FULL_MODE */
#endif

181
src/crypto/x509.c Normal file
View File

@ -0,0 +1,181 @@
/*
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <gpxe/asn1.h>
#include <gpxe/x509.h>
/** @file
*
* X.509 certificates
*
* The structure of X.509v3 certificates is concisely documented in
* RFC5280 section 4.1. The structure of RSA public keys is
* documented in RFC2313.
*/
/** Object Identifier for "rsaEncryption" (1.2.840.113549.1.1.1) */
static const uint8_t oid_rsa_encryption[] = { 0x2a, 0x86, 0x48, 0x86, 0xf7,
0x0d, 0x01, 0x01, 0x01 };
/**
* Identify X.509 certificate public key
*
* @v certificate Certificate
* @v algorithm Public key algorithm to fill in
* @v pubkey Public key value to fill in
* @ret rc Return status code
*/
static int x509_public_key ( const struct asn1_cursor *certificate,
struct asn1_cursor *algorithm,
struct asn1_cursor *pubkey ) {
struct asn1_cursor cursor;
int rc;
/* Locate subjectPublicKeyInfo */
memcpy ( &cursor, certificate, sizeof ( cursor ) );
rc = ( asn1_enter ( &cursor, ASN1_SEQUENCE ), /* Certificate */
asn1_enter ( &cursor, ASN1_SEQUENCE ), /* tbsCertificate */
asn1_skip ( &cursor, ASN1_EXPLICIT_TAG ), /* version */
asn1_skip ( &cursor, ASN1_INTEGER ), /* serialNumber */
asn1_skip ( &cursor, ASN1_SEQUENCE ), /* signature */
asn1_skip ( &cursor, ASN1_SEQUENCE ), /* issuer */
asn1_skip ( &cursor, ASN1_SEQUENCE ), /* validity */
asn1_skip ( &cursor, ASN1_SEQUENCE ), /* name */
asn1_enter ( &cursor, ASN1_SEQUENCE )/* subjectPublicKeyInfo*/);
if ( rc != 0 ) {
DBG ( "Cannot locate subjectPublicKeyInfo in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return rc;
}
/* Locate algorithm */
memcpy ( algorithm, &cursor, sizeof ( *algorithm ) );
rc = ( asn1_enter ( algorithm, ASN1_SEQUENCE ) /* algorithm */ );
if ( rc != 0 ) {
DBG ( "Cannot locate algorithm in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return rc;
}
/* Locate subjectPublicKey */
memcpy ( pubkey, &cursor, sizeof ( *pubkey ) );
rc = ( asn1_skip ( pubkey, ASN1_SEQUENCE ), /* algorithm */
asn1_enter ( pubkey, ASN1_BIT_STRING ) /* subjectPublicKey*/ );
if ( rc != 0 ) {
DBG ( "Cannot locate subjectPublicKey in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return rc;
}
return 0;
}
/**
* Identify X.509 certificate RSA modulus and public exponent
*
* @v certificate Certificate
* @v rsa RSA public key to fill in
* @ret rc Return status code
*
* The caller is responsible for eventually calling
* x509_free_rsa_public_key() to free the storage allocated to hold
* the RSA modulus and exponent.
*/
int x509_rsa_public_key ( const struct asn1_cursor *certificate,
struct x509_rsa_public_key *rsa_pubkey ) {
struct asn1_cursor algorithm;
struct asn1_cursor pubkey;
struct asn1_cursor modulus;
struct asn1_cursor exponent;
int rc;
/* First, extract the public key algorithm and key data */
if ( ( rc = x509_public_key ( certificate, &algorithm,
&pubkey ) ) != 0 )
return rc;
/* Check that algorithm is RSA */
rc = ( asn1_enter ( &algorithm, ASN1_OID ) /* algorithm */ );
if ( rc != 0 ) {
DBG ( "Cannot locate algorithm:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return rc;
}
if ( ( algorithm.len != sizeof ( oid_rsa_encryption ) ) ||
( memcmp ( algorithm.data, &oid_rsa_encryption,
sizeof ( oid_rsa_encryption ) ) != 0 ) ) {
DBG ( "algorithm is not rsaEncryption in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return -ENOTSUP;
}
/* Check that public key is a byte string, i.e. that the
* "unused bits" byte contains zero.
*/
if ( ( pubkey.len < 1 ) ||
( ( *( uint8_t * ) pubkey.data ) != 0 ) ) {
DBG ( "subjectPublicKey is not a byte string in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return -ENOTSUP;
}
pubkey.data++;
pubkey.len--;
/* Pick out the modulus and exponent */
rc = ( asn1_enter ( &pubkey, ASN1_SEQUENCE ) /* RSAPublicKey */ );
if ( rc != 0 ) {
DBG ( "Cannot locate RSAPublicKey in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return -ENOTSUP;
}
memcpy ( &modulus, &pubkey, sizeof ( modulus ) );
rc = ( asn1_enter ( &modulus, ASN1_INTEGER ) /* modulus */ );
if ( rc != 0 ) {
DBG ( "Cannot locate modulus in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return -ENOTSUP;
}
memcpy ( &exponent, &pubkey, sizeof ( exponent ) );
rc = ( asn1_skip ( &exponent, ASN1_INTEGER ), /* modulus */
asn1_enter ( &exponent, ASN1_INTEGER ) /* publicExponent */ );
if ( rc != 0 ) {
DBG ( "Cannot locate publicExponent in:\n" );
DBG_HDA ( 0, certificate->data, certificate->len );
return -ENOTSUP;
}
/* Allocate space and copy out modulus and exponent */
rsa_pubkey->modulus = malloc ( modulus.len + exponent.len );
if ( ! rsa_pubkey->modulus )
return -ENOMEM;
rsa_pubkey->exponent = ( rsa_pubkey->modulus + modulus.len );
memcpy ( rsa_pubkey->modulus, modulus.data, modulus.len );
rsa_pubkey->modulus_len = modulus.len;
memcpy ( rsa_pubkey->exponent, exponent.data, exponent.len );
rsa_pubkey->exponent_len = exponent.len;
DBG2 ( "RSA modulus:\n" );
DBG2_HDA ( 0, rsa_pubkey->modulus, rsa_pubkey->modulus_len );
DBG2 ( "RSA exponent:\n" );
DBG2_HDA ( 0, rsa_pubkey->exponent, rsa_pubkey->exponent_len );
return 0;
}

6
src/include/gpxe/asn1.h
View File

@ -21,12 +21,12 @@
*/
struct asn1_cursor {
/** Start of data */
uint8_t *data;
void *data;
/** Length of data */
size_t len;
};
extern int asn1_enter_object ( struct asn1_cursor *cursor, unsigned int type );
extern int asn1_skip_object ( struct asn1_cursor *cursor, unsigned int type );
extern int asn1_enter ( struct asn1_cursor *cursor, unsigned int type );
extern int asn1_skip ( struct asn1_cursor *cursor, unsigned int type );
#endif /* _GPXE_ASN1_H */

1
src/include/gpxe/errfile.h
View File

@ -168,6 +168,7 @@
#define ERRFILE_smbios_settings ( ERRFILE_OTHER | 0x00130000 )
#define ERRFILE_efi_smbios ( ERRFILE_OTHER | 0x00140000 )
#define ERRFILE_pxemenu ( ERRFILE_OTHER | 0x00150000 )
#define ERRFILE_x509 ( ERRFILE_OTHER | 0x00160000 )
/** @} */

6
src/include/gpxe/tls.h
View File

@ -14,6 +14,7 @@
#include <gpxe/crypto.h>
#include <gpxe/md5.h>
#include <gpxe/sha1.h>
#include <gpxe/x509.h>
/** A TLS header */
struct tls_header {
@ -157,10 +158,7 @@ struct tls_session {
uint8_t handshake_sha1_ctx[SHA1_CTX_SIZE];
/** Hack: server RSA public key */
uint8_t *rsa_mod;
size_t rsa_mod_len;
uint8_t *rsa_pub_exp;
size_t rsa_pub_exp_len;
struct x509_rsa_public_key rsa;
/** TX sequence number */
uint64_t tx_seq;

39
src/include/gpxe/x509.h Normal file
View File

@ -0,0 +1,39 @@
#ifndef _GPXE_X509_H
#define _GPXE_X509_H
/** @file
*
* X.509 certificates
*
*/
#include <stdint.h>
struct asn1_cursor;
/** An X.509 RSA public key */
struct x509_rsa_public_key {
/** Modulus */
uint8_t *modulus;
/** Modulus length */
size_t modulus_len;
/** Exponent */
uint8_t *exponent;
/** Exponent length */
size_t exponent_len;
};
/**
* Free X.509 RSA public key
*
* @v rsa_pubkey RSA public key
*/
static inline void
x509_free_rsa_public_key ( struct x509_rsa_public_key *rsa_pubkey ) {
free ( rsa_pubkey->modulus );
}
extern int x509_rsa_public_key ( const struct asn1_cursor *certificate,
struct x509_rsa_public_key *rsa_pubkey );
#endif /* _GPXE_X509_H */

175
src/net/tls.c
View File

@ -36,6 +36,8 @@
#include <gpxe/xfer.h>
#include <gpxe/open.h>
#include <gpxe/filter.h>
#include <gpxe/asn1.h>
#include <gpxe/x509.h>
#include <gpxe/tls.h>
static int tls_send_plaintext ( struct tls_session *tls, unsigned int type,
@ -43,6 +45,33 @@ static int tls_send_plaintext ( struct tls_session *tls, unsigned int type,
static void tls_clear_cipher ( struct tls_session *tls,
struct tls_cipherspec *cipherspec );
/******************************************************************************
*
* Utility functions
*
******************************************************************************
*/
/**
* Extract 24-bit field value
*
* @v field24 24-bit field
* @ret value Field value
*
* TLS uses 24-bit integers in several places, which are awkward to
* parse in C.
*/
static unsigned long tls_uint24 ( uint8_t field24[3] ) {
return ( ( field24[0] << 16 ) + ( field24[1] << 8 ) + field24[2] );
}
/******************************************************************************
*
* Cleanup functions
*
******************************************************************************
*/
/**
* Free TLS session
*
@ -57,8 +86,7 @@ static void free_tls ( struct refcnt *refcnt ) {
tls_clear_cipher ( tls, &tls->tx_cipherspec_pending );
tls_clear_cipher ( tls, &tls->rx_cipherspec );
tls_clear_cipher ( tls, &tls->rx_cipherspec_pending );
free ( tls->rsa_mod );
free ( tls->rsa_pub_exp );
x509_free_rsa_public_key ( &tls->rsa );
free ( tls->rx_data );
/* Free TLS structure itself */
@ -622,8 +650,8 @@ static int tls_send_client_hello ( struct tls_session *tls ) {
static int tls_send_client_key_exchange ( struct tls_session *tls ) {
/* FIXME: Hack alert */
RSA_CTX *rsa_ctx;
RSA_pub_key_new ( &rsa_ctx, tls->rsa_mod, tls->rsa_mod_len,
tls->rsa_pub_exp, tls->rsa_pub_exp_len );
RSA_pub_key_new ( &rsa_ctx, tls->rsa.modulus, tls->rsa.modulus_len,
tls->rsa.exponent, tls->rsa.exponent_len );
struct {
uint32_t type_length;
uint16_t encrypted_pre_master_secret_len;
@ -641,8 +669,8 @@ static int tls_send_client_key_exchange ( struct tls_session *tls ) {
DBGC ( tls, "RSA encrypting plaintext, modulus, exponent:\n" );
DBGC_HD ( tls, &tls->pre_master_secret,
sizeof ( tls->pre_master_secret ) );
DBGC_HD ( tls, tls->rsa_mod, tls->rsa_mod_len );
DBGC_HD ( tls, tls->rsa_pub_exp, tls->rsa_pub_exp_len );
DBGC_HD ( tls, tls->rsa.modulus, tls->rsa.modulus_len );
DBGC_HD ( tls, tls->rsa.exponent, tls->rsa.exponent_len );
RSA_encrypt ( rsa_ctx, ( const uint8_t * ) &tls->pre_master_secret,
sizeof ( tls->pre_master_secret ),
key_xchg.encrypted_pre_master_secret, 0 );
@ -761,17 +789,16 @@ static int tls_new_alert ( struct tls_session *tls, void *data, size_t len ) {
}
/**
* Receive new Server Hello record
* Receive new Server Hello handshake record
*
* @v tls TLS session
* @v data Plaintext record
* @v len Length of plaintext record
* @v data Plaintext handshake record
* @v len Length of plaintext handshake record
* @ret rc Return status code
*/
static int tls_new_server_hello ( struct tls_session *tls,
void *data, size_t len ) {
struct {
uint32_t type_length;
uint16_t version;
uint8_t random[32];
uint8_t session_id_len;
@ -818,72 +845,74 @@ static int tls_new_server_hello ( struct tls_session *tls,
}
/**
* Receive new Certificate record
* Receive new Certificate handshake record
*
* @v tls TLS session
* @v data Plaintext record
* @v len Length of plaintext record
* @v data Plaintext handshake record
* @v len Length of plaintext handshake record
* @ret rc Return status code
*/
static int tls_new_certificate ( struct tls_session *tls,
void *data, size_t len ) {
struct {
uint32_t type_length;
uint8_t length[3];
uint8_t first_cert_length[3];
uint8_t asn1_start[0];
uint8_t certificates[0];
} __attribute__ (( packed )) *certificate = data;
uint8_t *cert = certificate->asn1_start;
int offset = 0;
struct {
uint8_t length[3];
uint8_t certificate[0];
} __attribute__ (( packed )) *element =
( ( void * ) certificate->certificates );
size_t elements_len = tls_uint24 ( certificate->length );
void *end = ( certificate->certificates + elements_len );
struct asn1_cursor cursor;
int rc;
/* FIXME */
(void) len;
if (asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0 ||
asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0 ||
asn1_skip_obj(cert, &offset, ASN1_EXPLICIT_TAG) ||
asn1_skip_obj(cert, &offset, ASN1_INTEGER) ||
asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) ||
asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) ||
asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) ||
asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) ||
asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0 ||
asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) ||
asn1_next_obj(cert, &offset, ASN1_BIT_STRING) < 0) {
DBGC ( tls, "TLS %p invalid certificate\n", tls );
DBGC_HD ( tls, cert + offset, 64 );
return -EPERM;
/* Sanity check */
if ( end != ( data + len ) ) {
DBGC ( tls, "TLS %p received overlength Server Certificate\n",
tls );
DBGC_HD ( tls, data, len );
return -EINVAL;
}
offset++;
if (asn1_next_obj(cert, &offset, ASN1_SEQUENCE) < 0) {
DBGC ( tls, "TLS %p invalid certificate\n", tls );
DBGC_HD ( tls, cert + offset, 64 );
return -EPERM;
}
tls->rsa_mod_len = asn1_get_int(cert, &offset, &tls->rsa_mod);
tls->rsa_pub_exp_len = asn1_get_int(cert, &offset, &tls->rsa_pub_exp);
DBGC_HD ( tls, tls->rsa_mod, tls->rsa_mod_len );
DBGC_HD ( tls, tls->rsa_pub_exp, tls->rsa_pub_exp_len );
return 0;
/* Traverse certificate chain */
do {
cursor.data = element->certificate;
cursor.len = tls_uint24 ( element->length );
if ( ( cursor.data + cursor.len ) > end ) {
DBGC ( tls, "TLS %p received corrupt Server "
"Certificate\n", tls );
DBGC_HD ( tls, data, len );
return -EINVAL;
}
// HACK
if ( ( rc = x509_rsa_public_key ( &cursor,
&tls->rsa ) ) != 0 ) {
DBGC ( tls, "TLS %p cannot determine RSA public key: "
"%s\n", tls, strerror ( rc ) );
return rc;
}
return 0;
element = ( cursor.data + cursor.len );
} while ( element != end );
return -EINVAL;
}
/**
* Receive new Server Hello Done record
* Receive new Server Hello Done handshake record
*
* @v tls TLS session
* @v data Plaintext record
* @v len Length of plaintext record
* @v data Plaintext handshake record
* @v len Length of plaintext handshake record
* @ret rc Return status code
*/
static int tls_new_server_hello_done ( struct tls_session *tls,
void *data, size_t len ) {
struct {
uint32_t type_length;
char next[0];
} __attribute__ (( packed )) *hello_done = data;
void *end = hello_done->next;
@ -910,11 +939,11 @@ static int tls_new_server_hello_done ( struct tls_session *tls,
}
/**
* Receive new Finished record
* Receive new Finished handshake record
*
* @v tls TLS session
* @v data Plaintext record
* @v len Length of plaintext record
* @v data Plaintext handshake record
* @v len Length of plaintext handshake record
* @ret rc Return status code
*/
static int tls_new_finished ( struct tls_session *tls,
@ -937,33 +966,47 @@ static int tls_new_finished ( struct tls_session *tls,
*/
static int tls_new_handshake ( struct tls_session *tls,
void *data, size_t len ) {
uint8_t *type = data;
struct {
uint8_t type;
uint8_t length[3];
uint8_t payload[0];
} __attribute__ (( packed )) *handshake = data;
void *payload = &handshake->payload;
size_t payload_len = tls_uint24 ( handshake->length );
void *end = ( payload + payload_len );
int rc;
switch ( *type ) {
/* Sanity check */
if ( end != ( data + len ) ) {
DBGC ( tls, "TLS %p received overlength Handshake\n", tls );
DBGC_HD ( tls, data, len );
return -EINVAL;
}
switch ( handshake->type ) {
case TLS_SERVER_HELLO:
rc = tls_new_server_hello ( tls, data, len );
rc = tls_new_server_hello ( tls, payload, payload_len );
break;
case TLS_CERTIFICATE:
rc = tls_new_certificate ( tls, data, len );
rc = tls_new_certificate ( tls, payload, payload_len );
break;
case TLS_SERVER_HELLO_DONE:
rc = tls_new_server_hello_done ( tls, data, len );
rc = tls_new_server_hello_done ( tls, payload, payload_len );
break;
case TLS_FINISHED:
rc = tls_new_finished ( tls, data, len );
rc = tls_new_finished ( tls, payload, payload_len );
break;
default:
DBGC ( tls, "TLS %p ignoring handshake type %d\n",
tls, *type );
tls, handshake->type );
rc = 0;
break;
}
/* Add to handshake digest (except for Hello Requests, which
* are explicitly excludede).
* are explicitly excluded).
*/
if ( *type != TLS_HELLO_REQUEST )
if ( handshake->type != TLS_HELLO_REQUEST )
tls_add_handshake ( tls, data, len );
return rc;