Imported Upstream version 1.7.0upstream/1.7.0

1 files changed, 561 insertions, 0 deletions

diff --git a/ccast/axTLS/x509.c b/ccast/axTLS/x509.c
new file mode 100644
index 0000000..c2ca49f
--- /dev/null
+++ b/ccast/axTLS/x509.c
@@ -0,0 +1,561 @@
+/*
+ * Copyright (c) 2007, Cameron Rich
+ * 
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice, 
+ *   this list of conditions and the following disclaimer.
+ * * 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.
+ * * Neither the name of the axTLS project nor the names of its contributors 
+ *   may be used to endorse or promote products derived from this software 
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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 COPYRIGHT OWNER 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.
+ */
+
+/**
+ * @file x509.c
+ * 
+ * Certificate processing.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include "os_port.h"
+#include "crypto_misc.h"
+
+#ifdef CONFIG_SSL_CERT_VERIFICATION
+/**
+ * Retrieve the signature from a certificate.
+ */
+static const uint8_t *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
+
+/**
+ * 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 (SHA1/MD5/MD2) */
+    if (x509_ctx->sig_type == SIG_TYPE_MD5)
+    {
+        MD5_CTX md5_ctx;
+        uint8_t md5_dgst[MD5_SIZE];
+        MD5_Init(&md5_ctx);
+        MD5_Update(&md5_ctx, &cert[begin_tbs], end_tbs-begin_tbs);
+        MD5_Final(md5_dgst, &md5_ctx);
+        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];
+        SHA1_Init(&sha_ctx);
+        SHA1_Update(&sha_ctx, &cert[begin_tbs], end_tbs-begin_tbs);
+        SHA1_Final(sha_dgst, &sha_ctx);
+        x509_ctx->digest = bi_import(bi_ctx, sha_dgst, SHA1_SIZE);
+    }
+    else if (x509_ctx->sig_type == SIG_TYPE_MD2)
+    {
+        MD2_CTX md2_ctx;
+        uint8_t md2_dgst[MD2_SIZE];
+        MD2_Init(&md2_ctx);
+        MD2_Update(&md2_ctx, &cert[begin_tbs], end_tbs-begin_tbs);
+        MD2_Final(md2_dgst, &md2_ctx);
+        x509_ctx->digest = bi_import(bi_ctx, md2_dgst, MD2_SIZE);
+    }
+
+    if (cert[offset] == ASN1_V3_DATA)
+    {
+        int suboffset;
+
+        ++offset;
+        get_asn1_length(cert, &offset);
+
+        if ((suboffset = asn1_find_subjectaltname(cert, offset)) > 0)
+        {
+            if (asn1_next_obj(cert, &suboffset, ASN1_OCTET_STRING) > 0)
+            {
+                int altlen;
+
+                if ((altlen = asn1_next_obj(cert, 
+                                            &suboffset, ASN1_SEQUENCE)) > 0)
+                {
+                    int endalt = suboffset + altlen;
+                    int totalnames = 0;
+
+                    while (suboffset < endalt)
+                    {
+                        int type = cert[suboffset++];
+                        int dnslen = get_asn1_length(cert, &suboffset);
+
+                        if (type == ASN1_CONTEXT_DNSNAME)
+                        {
+                            x509_ctx->subject_alt_dnsnames = (char**)
+                                    realloc(x509_ctx->subject_alt_dnsnames, 
+                                       (totalnames + 2) * sizeof(char*));
+                            x509_ctx->subject_alt_dnsnames[totalnames] = 
+                                    (char*)malloc(dnslen + 1);
+                            x509_ctx->subject_alt_dnsnames[totalnames+1] = NULL;
+                            memcpy(x509_ctx->subject_alt_dnsnames[totalnames], 
+                                    cert + suboffset, dnslen);
+                            x509_ctx->subject_alt_dnsnames[
+                                    totalnames][dnslen] = 0;
+                            ++totalnames;
+                        }
+
+                        suboffset += dnslen;
+                    }
+                }
+            }
+        }
+    }
+
+    offset = end_tbs;   /* skip the rest of v3 data */
+    if (asn1_skip_obj(cert, &offset, ASN1_SEQUENCE) || 
+            asn1_signature(cert, &offset, x509_ctx))
+        goto end_cert;
+#endif
+    ret = X509_OK;
+end_cert:
+    if (len)
+    {
+        *len = cert_size;
+    }
+
+    if (ret)
+    {
+#ifdef CONFIG_SSL_FULL_MODE
+        printf("Error: Invalid X509 ASN.1 file (%s)\n",
+                        x509_display_error(ret));
+#endif
+        x509_free(x509_ctx);
+        *ctx = NULL;
+    }
+
+    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);
+    }
+
+    if (x509_ctx->subject_alt_dnsnames)
+    {
+        for (i = 0; x509_ctx->subject_alt_dnsnames[i]; ++i)
+            free(x509_ctx->subject_alt_dnsnames[i]);
+
+        free(x509_ctx->subject_alt_dnsnames);
+    }
+#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
+/**
+ * Take a signature and decrypt it.
+ */
+static bigint *sig_verify(BI_CTX *ctx, const uint8_t *sig, int sig_len,
+        bigint *modulus, bigint *pub_exp)
+{
+    int i, size;
+    bigint *decrypted_bi, *dat_bi;
+    bigint *bir = NULL;
+    uint8_t *block = (uint8_t *)malloc(sig_len);
+
+    /* decrypt */
+    dat_bi = bi_import(ctx, sig, sig_len);
+    ctx->mod_offset = BIGINT_M_OFFSET;
+
+    /* convert to a normal block */
+    decrypted_bi = bi_mod_power2(ctx, dat_bi, modulus, pub_exp);
+
+    bi_export(ctx, decrypted_bi, block, sig_len);
+    ctx->mod_offset = BIGINT_M_OFFSET;
+
+    i = 10; /* start at the first possible non-padded byte */
+    while (block[i++] && i < sig_len);
+    size = sig_len - i;
+
+    /* get only the bit we want */
+    if (size > 0)
+    {
+        int len;
+        const uint8_t *sig_ptr = get_signature(&block[i], &len);
+
+        if (sig_ptr)
+        {
+            bir = bi_import(ctx, sig_ptr, len);
+        }
+    }
+
+    /* save a few bytes of memory */
+    bi_clear_cache(ctx);
+	free(block);
+    return bir;
+}
+
+/**
+ * Do some basic checks on the certificate chain.
+ *
+ * Certificate verification consists of a number of checks:
+ * - The date of the certificate is after the start date.
+ * - The date of the certificate is before the finish date.
+ * - A root certificate exists in the certificate store.
+ * - That the certificate(s) are not self-signed.
+ * - The certificate chain is valid.
+ * - 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 = NULL;
+    bigint *mod = NULL, *expn = NULL;
+    int match_ca_cert = 0;
+    struct timeval tv;
+    uint8_t is_self_signed = 0;
+
+    if (cert == NULL)
+    {
+        ret = X509_VFY_ERROR_NO_TRUSTED_CERT;       
+        goto end_verify;
+    }
+
+    /* a self-signed certificate that is not in the CA store - use this 
+       to check the signature */
+    if (asn1_compare_dn(cert->ca_cert_dn, cert->cert_dn) == 0)
+    {
+        is_self_signed = 1;
+        ctx = cert->rsa_ctx->bi_ctx;
+        mod = cert->rsa_ctx->m;
+        expn = cert->rsa_ctx->e;
+    }
+
+    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;
+    }
+
+    next_cert = cert->next;
+
+    /* last cert in the chain - look for a trusted cert */
+    if (next_cert == NULL)
+    {
+       if (ca_cert_ctx != NULL) 
+       {
+            /* go thu the CA store */
+            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)
+                {
+                    /* use this CA certificate for signature verification */
+                    match_ca_cert = 1;
+                    ctx = ca_cert_ctx->cert[i]->rsa_ctx->bi_ctx;
+                    mod = ca_cert_ctx->cert[i]->rsa_ctx->m;
+                    expn = ca_cert_ctx->cert[i]->rsa_ctx->e;
+                    break;
+                }
+
+                i++;
+            }
+        }
+
+        /* couldn't find a trusted cert (& let self-signed errors 
+           be returned) */
+        if (!match_ca_cert && !is_self_signed)
+        {
+            ret = X509_VFY_ERROR_NO_TRUSTED_CERT;       
+            goto end_verify;
+        }
+    }
+    else if (asn1_compare_dn(cert->ca_cert_dn, next_cert->cert_dn) != 0)
+    {
+        /* check the chain */
+        ret = X509_VFY_ERROR_INVALID_CHAIN;
+        goto end_verify;
+    }
+    else /* use the next certificate in the chain for signature verify */
+    {
+        ctx = next_cert->rsa_ctx->bi_ctx;
+        mod = next_cert->rsa_ctx->m;
+        expn = next_cert->rsa_ctx->e;
+    }
+
+    /* cert is self signed */
+    if (!match_ca_cert && is_self_signed)
+    {
+        ret = X509_VFY_ERROR_SELF_SIGNED;
+        goto end_verify;
+    }
+
+    /* check the signature */
+    cert_sig = sig_verify(ctx, cert->signature, cert->sig_len, 
+                        bi_clone(ctx, mod), bi_clone(ctx, expn));
+
+    if (cert_sig && cert->digest)
+    {
+        if (bi_compare(cert_sig, cert->digest) != 0)
+            ret = X509_VFY_ERROR_BAD_SIGNATURE;
+
+
+        bi_free(ctx, cert_sig);
+    }
+    else
+    {
+        ret = X509_VFY_ERROR_BAD_SIGNATURE;
+    }
+
+    if (ret)
+        goto end_verify;
+
+    /* go down the certificate chain using recursion. */
+    if (next_cert != NULL)
+    {
+        ret = x509_verify(ca_cert_ctx, next_cert);
+    }
+
+end_verify:
+    return ret;
+}
+#endif
+
+#if defined (CONFIG_SSL_FULL_MODE)
+/**
+ * Used for diagnostics.
+ */
+static const char *not_part_of_cert = "<Not Part Of Certificate>";
+void x509_print(const X509_CTX *cert, CA_CERT_CTX *ca_cert_ctx) 
+{
+    if (cert == NULL)
+        return;
+
+    printf("=== CERTIFICATE ISSUED TO ===\n");
+    printf("Common Name (CN):\t\t");
+    printf("%s\n", cert->cert_dn[X509_COMMON_NAME] ?
+                    cert->cert_dn[X509_COMMON_NAME] : not_part_of_cert);
+
+    printf("Organization (O):\t\t");
+    printf("%s\n", cert->cert_dn[X509_ORGANIZATION] ?
+        cert->cert_dn[X509_ORGANIZATION] : not_part_of_cert);
+
+    printf("Organizational Unit (OU):\t");
+    printf("%s\n", cert->cert_dn[X509_ORGANIZATIONAL_UNIT] ?
+        cert->cert_dn[X509_ORGANIZATIONAL_UNIT] : not_part_of_cert);
+
+    printf("=== CERTIFICATE ISSUED BY ===\n");
+    printf("Common Name (CN):\t\t");
+    printf("%s\n", cert->ca_cert_dn[X509_COMMON_NAME] ?
+                    cert->ca_cert_dn[X509_COMMON_NAME] : not_part_of_cert);
+
+    printf("Organization (O):\t\t");
+    printf("%s\n", cert->ca_cert_dn[X509_ORGANIZATION] ?
+        cert->ca_cert_dn[X509_ORGANIZATION] : not_part_of_cert);
+
+    printf("Organizational Unit (OU):\t");
+    printf("%s\n", cert->ca_cert_dn[X509_ORGANIZATIONAL_UNIT] ?
+        cert->ca_cert_dn[X509_ORGANIZATIONAL_UNIT] : not_part_of_cert);
+
+    printf("Not Before:\t\t\t%s", ctime(&cert->not_before));
+    printf("Not After:\t\t\t%s", ctime(&cert->not_after));
+    printf("RSA bitsize:\t\t\t%d\n", cert->rsa_ctx->num_octets*8);
+    printf("Sig Type:\t\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;
+    }
+
+    if (ca_cert_ctx)
+    {
+        printf("Verify:\t\t\t\t%s\n",
+                x509_display_error(x509_verify(ca_cert_ctx, cert)));
+    }
+
+#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(cert->next, ca_cert_ctx);
+    }
+
+    TTY_FLUSH();
+}
+
+#endif      /* CONFIG_SSL_FULL_MODE */
+
+const char * x509_display_error(int error)
+{
+    switch (error)
+    {
+        case X509_OK:
+            return "Certificate verify successful";
+
+        case X509_NOT_OK:
+            return "X509 not ok";
+
+        case X509_VFY_ERROR_NO_TRUSTED_CERT:
+            return "No trusted cert is available";
+
+        case X509_VFY_ERROR_BAD_SIGNATURE:
+            return "Bad signature";
+
+        case X509_VFY_ERROR_NOT_YET_VALID:
+            return "Cert is not yet valid";
+
+        case X509_VFY_ERROR_EXPIRED:
+            return "Cert has expired";
+
+        case X509_VFY_ERROR_SELF_SIGNED:
+            return "Cert is self-signed";
+
+        case X509_VFY_ERROR_INVALID_CHAIN:
+            return "Chain is invalid (check order of certs)";
+
+        case X509_VFY_ERROR_UNSUPPORTED_DIGEST:
+            return "Unsupported digest";
+
+        case X509_INVALID_PRIV_KEY:
+            return "Invalid private key";
+
+        default:
+            return "Unknown";
+    }
+}
+