lib: crypto: add x509 parser
Imported from linux kernel v5.3:
x509.asn1 without changes
x509_akid.asn1 without changes
x509_parser.h without changes
x509_cert_parser.c with changes marked as __UBOOT__
x509_public_key.c with changes marked as __UBOOT__
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/lib/crypto/x509_cert_parser.c b/lib/crypto/x509_cert_parser.c
new file mode 100644
index 0000000..e6d2a42
--- /dev/null
+++ b/lib/crypto/x509_cert_parser.c
@@ -0,0 +1,697 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* X.509 certificate parser
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) "X.509: "fmt
+#include <linux/kernel.h>
+#ifndef __UBOOT__
+#include <linux/export.h>
+#include <linux/slab.h>
+#endif
+#include <linux/err.h>
+#include <linux/oid_registry.h>
+#ifdef __UBOOT__
+#include <linux/string.h>
+#endif
+#include <crypto/public_key.h>
+#include "x509_parser.h"
+#include "x509.asn1.h"
+#include "x509_akid.asn1.h"
+
+struct x509_parse_context {
+ struct x509_certificate *cert; /* Certificate being constructed */
+ unsigned long data; /* Start of data */
+ const void *cert_start; /* Start of cert content */
+ const void *key; /* Key data */
+ size_t key_size; /* Size of key data */
+ const void *params; /* Key parameters */
+ size_t params_size; /* Size of key parameters */
+ enum OID key_algo; /* Public key algorithm */
+ enum OID last_oid; /* Last OID encountered */
+ enum OID algo_oid; /* Algorithm OID */
+ unsigned char nr_mpi; /* Number of MPIs stored */
+ u8 o_size; /* Size of organizationName (O) */
+ u8 cn_size; /* Size of commonName (CN) */
+ u8 email_size; /* Size of emailAddress */
+ u16 o_offset; /* Offset of organizationName (O) */
+ u16 cn_offset; /* Offset of commonName (CN) */
+ u16 email_offset; /* Offset of emailAddress */
+ unsigned raw_akid_size;
+ const void *raw_akid; /* Raw authorityKeyId in ASN.1 */
+ const void *akid_raw_issuer; /* Raw directoryName in authorityKeyId */
+ unsigned akid_raw_issuer_size;
+};
+
+/*
+ * Free an X.509 certificate
+ */
+void x509_free_certificate(struct x509_certificate *cert)
+{
+ if (cert) {
+ public_key_free(cert->pub);
+ public_key_signature_free(cert->sig);
+ kfree(cert->issuer);
+ kfree(cert->subject);
+ kfree(cert->id);
+ kfree(cert->skid);
+ kfree(cert);
+ }
+}
+EXPORT_SYMBOL_GPL(x509_free_certificate);
+
+/*
+ * Parse an X.509 certificate
+ */
+struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
+{
+ struct x509_certificate *cert;
+ struct x509_parse_context *ctx;
+ struct asymmetric_key_id *kid;
+ long ret;
+
+ ret = -ENOMEM;
+ cert = kzalloc(sizeof(struct x509_certificate), GFP_KERNEL);
+ if (!cert)
+ goto error_no_cert;
+ cert->pub = kzalloc(sizeof(struct public_key), GFP_KERNEL);
+ if (!cert->pub)
+ goto error_no_ctx;
+ cert->sig = kzalloc(sizeof(struct public_key_signature), GFP_KERNEL);
+ if (!cert->sig)
+ goto error_no_ctx;
+ ctx = kzalloc(sizeof(struct x509_parse_context), GFP_KERNEL);
+ if (!ctx)
+ goto error_no_ctx;
+
+ ctx->cert = cert;
+ ctx->data = (unsigned long)data;
+
+ /* Attempt to decode the certificate */
+ ret = asn1_ber_decoder(&x509_decoder, ctx, data, datalen);
+ if (ret < 0)
+ goto error_decode;
+
+ /* Decode the AuthorityKeyIdentifier */
+ if (ctx->raw_akid) {
+ pr_devel("AKID: %u %*phN\n",
+ ctx->raw_akid_size, ctx->raw_akid_size, ctx->raw_akid);
+ ret = asn1_ber_decoder(&x509_akid_decoder, ctx,
+ ctx->raw_akid, ctx->raw_akid_size);
+ if (ret < 0) {
+ pr_warn("Couldn't decode AuthKeyIdentifier\n");
+ goto error_decode;
+ }
+ }
+
+ ret = -ENOMEM;
+ cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
+ if (!cert->pub->key)
+ goto error_decode;
+
+ cert->pub->keylen = ctx->key_size;
+
+ cert->pub->params = kmemdup(ctx->params, ctx->params_size, GFP_KERNEL);
+ if (!cert->pub->params)
+ goto error_decode;
+
+ cert->pub->paramlen = ctx->params_size;
+ cert->pub->algo = ctx->key_algo;
+
+ /* Grab the signature bits */
+ ret = x509_get_sig_params(cert);
+ if (ret < 0)
+ goto error_decode;
+
+ /* Generate cert issuer + serial number key ID */
+ kid = asymmetric_key_generate_id(cert->raw_serial,
+ cert->raw_serial_size,
+ cert->raw_issuer,
+ cert->raw_issuer_size);
+ if (IS_ERR(kid)) {
+ ret = PTR_ERR(kid);
+ goto error_decode;
+ }
+ cert->id = kid;
+
+#ifndef __UBOOT__
+ /* Detect self-signed certificates */
+ ret = x509_check_for_self_signed(cert);
+ if (ret < 0)
+ goto error_decode;
+#endif
+
+ kfree(ctx);
+ return cert;
+
+error_decode:
+ kfree(ctx);
+error_no_ctx:
+ x509_free_certificate(cert);
+error_no_cert:
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(x509_cert_parse);
+
+/*
+ * Note an OID when we find one for later processing when we know how
+ * to interpret it.
+ */
+int x509_note_OID(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ ctx->last_oid = look_up_OID(value, vlen);
+ if (ctx->last_oid == OID__NR) {
+ char buffer[50];
+ sprint_oid(value, vlen, buffer, sizeof(buffer));
+ pr_debug("Unknown OID: [%lu] %s\n",
+ (unsigned long)value - ctx->data, buffer);
+ }
+ return 0;
+}
+
+/*
+ * Save the position of the TBS data so that we can check the signature over it
+ * later.
+ */
+int x509_note_tbs_certificate(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ pr_debug("x509_note_tbs_certificate(,%zu,%02x,%ld,%zu)!\n",
+ hdrlen, tag, (unsigned long)value - ctx->data, vlen);
+
+ ctx->cert->tbs = value - hdrlen;
+ ctx->cert->tbs_size = vlen + hdrlen;
+ return 0;
+}
+
+/*
+ * Record the public key algorithm
+ */
+int x509_note_pkey_algo(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ pr_debug("PubKey Algo: %u\n", ctx->last_oid);
+
+ switch (ctx->last_oid) {
+ case OID_md2WithRSAEncryption:
+ case OID_md3WithRSAEncryption:
+ default:
+ return -ENOPKG; /* Unsupported combination */
+
+ case OID_md4WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "md4";
+ goto rsa_pkcs1;
+
+ case OID_sha1WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha1";
+ goto rsa_pkcs1;
+
+ case OID_sha256WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha256";
+ goto rsa_pkcs1;
+
+ case OID_sha384WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha384";
+ goto rsa_pkcs1;
+
+ case OID_sha512WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha512";
+ goto rsa_pkcs1;
+
+ case OID_sha224WithRSAEncryption:
+ ctx->cert->sig->hash_algo = "sha224";
+ goto rsa_pkcs1;
+
+ case OID_gost2012Signature256:
+ ctx->cert->sig->hash_algo = "streebog256";
+ goto ecrdsa;
+
+ case OID_gost2012Signature512:
+ ctx->cert->sig->hash_algo = "streebog512";
+ goto ecrdsa;
+ }
+
+rsa_pkcs1:
+ ctx->cert->sig->pkey_algo = "rsa";
+ ctx->cert->sig->encoding = "pkcs1";
+ ctx->algo_oid = ctx->last_oid;
+ return 0;
+ecrdsa:
+ ctx->cert->sig->pkey_algo = "ecrdsa";
+ ctx->cert->sig->encoding = "raw";
+ ctx->algo_oid = ctx->last_oid;
+ return 0;
+}
+
+/*
+ * Note the whereabouts and type of the signature.
+ */
+int x509_note_signature(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ pr_debug("Signature type: %u size %zu\n", ctx->last_oid, vlen);
+
+ if (ctx->last_oid != ctx->algo_oid) {
+ pr_warn("Got cert with pkey (%u) and sig (%u) algorithm OIDs\n",
+ ctx->algo_oid, ctx->last_oid);
+ return -EINVAL;
+ }
+
+ if (strcmp(ctx->cert->sig->pkey_algo, "rsa") == 0 ||
+ strcmp(ctx->cert->sig->pkey_algo, "ecrdsa") == 0) {
+ /* Discard the BIT STRING metadata */
+ if (vlen < 1 || *(const u8 *)value != 0)
+ return -EBADMSG;
+
+ value++;
+ vlen--;
+ }
+
+ ctx->cert->raw_sig = value;
+ ctx->cert->raw_sig_size = vlen;
+ return 0;
+}
+
+/*
+ * Note the certificate serial number
+ */
+int x509_note_serial(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ ctx->cert->raw_serial = value;
+ ctx->cert->raw_serial_size = vlen;
+ return 0;
+}
+
+/*
+ * Note some of the name segments from which we'll fabricate a name.
+ */
+int x509_extract_name_segment(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ switch (ctx->last_oid) {
+ case OID_commonName:
+ ctx->cn_size = vlen;
+ ctx->cn_offset = (unsigned long)value - ctx->data;
+ break;
+ case OID_organizationName:
+ ctx->o_size = vlen;
+ ctx->o_offset = (unsigned long)value - ctx->data;
+ break;
+ case OID_email_address:
+ ctx->email_size = vlen;
+ ctx->email_offset = (unsigned long)value - ctx->data;
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * Fabricate and save the issuer and subject names
+ */
+static int x509_fabricate_name(struct x509_parse_context *ctx, size_t hdrlen,
+ unsigned char tag,
+ char **_name, size_t vlen)
+{
+ const void *name, *data = (const void *)ctx->data;
+ size_t namesize;
+ char *buffer;
+
+ if (*_name)
+ return -EINVAL;
+
+ /* Empty name string if no material */
+ if (!ctx->cn_size && !ctx->o_size && !ctx->email_size) {
+ buffer = kmalloc(1, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+ buffer[0] = 0;
+ goto done;
+ }
+
+ if (ctx->cn_size && ctx->o_size) {
+ /* Consider combining O and CN, but use only the CN if it is
+ * prefixed by the O, or a significant portion thereof.
+ */
+ namesize = ctx->cn_size;
+ name = data + ctx->cn_offset;
+ if (ctx->cn_size >= ctx->o_size &&
+ memcmp(data + ctx->cn_offset, data + ctx->o_offset,
+ ctx->o_size) == 0)
+ goto single_component;
+ if (ctx->cn_size >= 7 &&
+ ctx->o_size >= 7 &&
+ memcmp(data + ctx->cn_offset, data + ctx->o_offset, 7) == 0)
+ goto single_component;
+
+ buffer = kmalloc(ctx->o_size + 2 + ctx->cn_size + 1,
+ GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ memcpy(buffer,
+ data + ctx->o_offset, ctx->o_size);
+ buffer[ctx->o_size + 0] = ':';
+ buffer[ctx->o_size + 1] = ' ';
+ memcpy(buffer + ctx->o_size + 2,
+ data + ctx->cn_offset, ctx->cn_size);
+ buffer[ctx->o_size + 2 + ctx->cn_size] = 0;
+ goto done;
+
+ } else if (ctx->cn_size) {
+ namesize = ctx->cn_size;
+ name = data + ctx->cn_offset;
+ } else if (ctx->o_size) {
+ namesize = ctx->o_size;
+ name = data + ctx->o_offset;
+ } else {
+ namesize = ctx->email_size;
+ name = data + ctx->email_offset;
+ }
+
+single_component:
+ buffer = kmalloc(namesize + 1, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+ memcpy(buffer, name, namesize);
+ buffer[namesize] = 0;
+
+done:
+ *_name = buffer;
+ ctx->cn_size = 0;
+ ctx->o_size = 0;
+ ctx->email_size = 0;
+ return 0;
+}
+
+int x509_note_issuer(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ ctx->cert->raw_issuer = value;
+ ctx->cert->raw_issuer_size = vlen;
+ return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->issuer, vlen);
+}
+
+int x509_note_subject(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ ctx->cert->raw_subject = value;
+ ctx->cert->raw_subject_size = vlen;
+ return x509_fabricate_name(ctx, hdrlen, tag, &ctx->cert->subject, vlen);
+}
+
+/*
+ * Extract the parameters for the public key
+ */
+int x509_note_params(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ /*
+ * AlgorithmIdentifier is used three times in the x509, we should skip
+ * first and ignore third, using second one which is after subject and
+ * before subjectPublicKey.
+ */
+ if (!ctx->cert->raw_subject || ctx->key)
+ return 0;
+ ctx->params = value - hdrlen;
+ ctx->params_size = vlen + hdrlen;
+ return 0;
+}
+
+/*
+ * Extract the data for the public key algorithm
+ */
+int x509_extract_key_data(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ ctx->key_algo = ctx->last_oid;
+ if (ctx->last_oid == OID_rsaEncryption)
+ ctx->cert->pub->pkey_algo = "rsa";
+ else if (ctx->last_oid == OID_gost2012PKey256 ||
+ ctx->last_oid == OID_gost2012PKey512)
+ ctx->cert->pub->pkey_algo = "ecrdsa";
+ else
+ return -ENOPKG;
+
+ /* Discard the BIT STRING metadata */
+ if (vlen < 1 || *(const u8 *)value != 0)
+ return -EBADMSG;
+ ctx->key = value + 1;
+ ctx->key_size = vlen - 1;
+ return 0;
+}
+
+/* The keyIdentifier in AuthorityKeyIdentifier SEQUENCE is tag(CONT,PRIM,0) */
+#define SEQ_TAG_KEYID (ASN1_CONT << 6)
+
+/*
+ * Process certificate extensions that are used to qualify the certificate.
+ */
+int x509_process_extension(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ struct asymmetric_key_id *kid;
+ const unsigned char *v = value;
+
+ pr_debug("Extension: %u\n", ctx->last_oid);
+
+ if (ctx->last_oid == OID_subjectKeyIdentifier) {
+ /* Get hold of the key fingerprint */
+ if (ctx->cert->skid || vlen < 3)
+ return -EBADMSG;
+ if (v[0] != ASN1_OTS || v[1] != vlen - 2)
+ return -EBADMSG;
+ v += 2;
+ vlen -= 2;
+
+ ctx->cert->raw_skid_size = vlen;
+ ctx->cert->raw_skid = v;
+ kid = asymmetric_key_generate_id(v, vlen, "", 0);
+ if (IS_ERR(kid))
+ return PTR_ERR(kid);
+ ctx->cert->skid = kid;
+ pr_debug("subjkeyid %*phN\n", kid->len, kid->data);
+ return 0;
+ }
+
+ if (ctx->last_oid == OID_authorityKeyIdentifier) {
+ /* Get hold of the CA key fingerprint */
+ ctx->raw_akid = v;
+ ctx->raw_akid_size = vlen;
+ return 0;
+ }
+
+ return 0;
+}
+
+/**
+ * x509_decode_time - Decode an X.509 time ASN.1 object
+ * @_t: The time to fill in
+ * @hdrlen: The length of the object header
+ * @tag: The object tag
+ * @value: The object value
+ * @vlen: The size of the object value
+ *
+ * Decode an ASN.1 universal time or generalised time field into a struct the
+ * kernel can handle and check it for validity. The time is decoded thus:
+ *
+ * [RFC5280 §4.1.2.5]
+ * CAs conforming to this profile MUST always encode certificate validity
+ * dates through the year 2049 as UTCTime; certificate validity dates in
+ * 2050 or later MUST be encoded as GeneralizedTime. Conforming
+ * applications MUST be able to process validity dates that are encoded in
+ * either UTCTime or GeneralizedTime.
+ */
+int x509_decode_time(time64_t *_t, size_t hdrlen,
+ unsigned char tag,
+ const unsigned char *value, size_t vlen)
+{
+ static const unsigned char month_lengths[] = { 31, 28, 31, 30, 31, 30,
+ 31, 31, 30, 31, 30, 31 };
+ const unsigned char *p = value;
+ unsigned year, mon, day, hour, min, sec, mon_len;
+
+#define dec2bin(X) ({ unsigned char x = (X) - '0'; if (x > 9) goto invalid_time; x; })
+#define DD2bin(P) ({ unsigned x = dec2bin(P[0]) * 10 + dec2bin(P[1]); P += 2; x; })
+
+ if (tag == ASN1_UNITIM) {
+ /* UTCTime: YYMMDDHHMMSSZ */
+ if (vlen != 13)
+ goto unsupported_time;
+ year = DD2bin(p);
+ if (year >= 50)
+ year += 1900;
+ else
+ year += 2000;
+ } else if (tag == ASN1_GENTIM) {
+ /* GenTime: YYYYMMDDHHMMSSZ */
+ if (vlen != 15)
+ goto unsupported_time;
+ year = DD2bin(p) * 100 + DD2bin(p);
+ if (year >= 1950 && year <= 2049)
+ goto invalid_time;
+ } else {
+ goto unsupported_time;
+ }
+
+ mon = DD2bin(p);
+ day = DD2bin(p);
+ hour = DD2bin(p);
+ min = DD2bin(p);
+ sec = DD2bin(p);
+
+ if (*p != 'Z')
+ goto unsupported_time;
+
+ if (year < 1970 ||
+ mon < 1 || mon > 12)
+ goto invalid_time;
+
+ mon_len = month_lengths[mon - 1];
+ if (mon == 2) {
+ if (year % 4 == 0) {
+ mon_len = 29;
+ if (year % 100 == 0) {
+ mon_len = 28;
+ if (year % 400 == 0)
+ mon_len = 29;
+ }
+ }
+ }
+
+ if (day < 1 || day > mon_len ||
+ hour > 24 || /* ISO 8601 permits 24:00:00 as midnight tomorrow */
+ min > 59 ||
+ sec > 60) /* ISO 8601 permits leap seconds [X.680 46.3] */
+ goto invalid_time;
+
+ *_t = mktime64(year, mon, day, hour, min, sec);
+ return 0;
+
+unsupported_time:
+ pr_debug("Got unsupported time [tag %02x]: '%*phN'\n",
+ tag, (int)vlen, value);
+ return -EBADMSG;
+invalid_time:
+ pr_debug("Got invalid time [tag %02x]: '%*phN'\n",
+ tag, (int)vlen, value);
+ return -EBADMSG;
+}
+EXPORT_SYMBOL_GPL(x509_decode_time);
+
+int x509_note_not_before(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ return x509_decode_time(&ctx->cert->valid_from, hdrlen, tag, value, vlen);
+}
+
+int x509_note_not_after(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ return x509_decode_time(&ctx->cert->valid_to, hdrlen, tag, value, vlen);
+}
+
+/*
+ * Note a key identifier-based AuthorityKeyIdentifier
+ */
+int x509_akid_note_kid(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ struct asymmetric_key_id *kid;
+
+ pr_debug("AKID: keyid: %*phN\n", (int)vlen, value);
+
+ if (ctx->cert->sig->auth_ids[1])
+ return 0;
+
+ kid = asymmetric_key_generate_id(value, vlen, "", 0);
+ if (IS_ERR(kid))
+ return PTR_ERR(kid);
+ pr_debug("authkeyid %*phN\n", kid->len, kid->data);
+ ctx->cert->sig->auth_ids[1] = kid;
+ return 0;
+}
+
+/*
+ * Note a directoryName in an AuthorityKeyIdentifier
+ */
+int x509_akid_note_name(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+
+ pr_debug("AKID: name: %*phN\n", (int)vlen, value);
+
+ ctx->akid_raw_issuer = value;
+ ctx->akid_raw_issuer_size = vlen;
+ return 0;
+}
+
+/*
+ * Note a serial number in an AuthorityKeyIdentifier
+ */
+int x509_akid_note_serial(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct x509_parse_context *ctx = context;
+ struct asymmetric_key_id *kid;
+
+ pr_debug("AKID: serial: %*phN\n", (int)vlen, value);
+
+ if (!ctx->akid_raw_issuer || ctx->cert->sig->auth_ids[0])
+ return 0;
+
+ kid = asymmetric_key_generate_id(value,
+ vlen,
+ ctx->akid_raw_issuer,
+ ctx->akid_raw_issuer_size);
+ if (IS_ERR(kid))
+ return PTR_ERR(kid);
+
+ pr_debug("authkeyid %*phN\n", kid->len, kid->data);
+ ctx->cert->sig->auth_ids[0] = kid;
+ return 0;
+}