[PATCH v4 08/28] crypto/x509-utils: Add helper functions for DIAG 320 subcode 2

[Zhuoying Cai <zycai@linux.ibm.com>]

Introduce new helper functions to extract certificate metadata needed for
DIAG 320 subcode 2:

qcrypto_x509_get_cert_version() - retrieves version of a certificate
qcrypto_x509_check_cert_times() - validates the certificate's validity period against the current time
qcrypto_x509_get_pk_algorithm() - returns the public key algorithm used in the certificate
qcrypto_x509_get_cert_key_id() - extracts the key ID from the certificate

These functions provide support for metadata extraction and validity checking
for X.509 certificates.

Signed-off-by: Zhuoying Cai <zycai@linux.ibm.com>
---
 crypto/x509-utils.c         | 199 ++++++++++++++++++++++++++++++++++++
 include/crypto/x509-utils.h |  76 +++++++++++++-
 2 files changed, 272 insertions(+), 3 deletions(-)

diff --git a/crypto/x509-utils.c b/crypto/x509-utils.c
index d2cf790d5b..135f83f55e 100644
--- a/crypto/x509-utils.c
+++ b/crypto/x509-utils.c
@@ -55,6 +55,14 @@ static const int gnutls_to_qcrypto_sig_alg_map[] = {
     [GNUTLS_SIGN_ECDSA_SHA512] = QCRYPTO_SIG_ALGO_ECDSA_SHA512,
 };
 
+static const int gnutls_to_qcrypto_pk_alg_map[] = {
+    [GNUTLS_PK_UNKNOWN] = QCRYPTO_PK_ALGO_UNKNOWN,
+    [GNUTLS_PK_RSA] = QCRYPTO_PK_ALGO_RSA,
+    [GNUTLS_PK_DSA] = QCRYPTO_PK_ALGO_DSA,
+    [GNUTLS_PK_DH] = QCRYPTO_PK_ALGO_DH,
+    [GNUTLS_PK_ECDSA] = QCRYPTO_PK_ALGO_ECDSA,
+};
+
 int qcrypto_x509_convert_cert_der(uint8_t *cert, size_t size,
                                   uint8_t **result, size_t *resultlen,
                                   Error **errp)
@@ -195,6 +203,169 @@ cleanup:
     return ret;
 }
 
+int qcrypto_x509_get_cert_version(uint8_t *cert, size_t size, Error **errp)
+{
+    int rc;
+    int ret = -1;
+    gnutls_x509_crt_t crt;
+    gnutls_datum_t datum = {.data = cert, .size = size};
+
+    rc = gnutls_x509_crt_init(&crt);
+    if (rc < 0) {
+        error_setg(errp, "Failed to initialize certificate: %s", gnutls_strerror(rc));
+        return ret;
+    }
+
+    rc = gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM);
+    if (rc != 0) {
+        error_setg(errp, "Failed to import certificate: %s", gnutls_strerror(rc));
+        goto cleanup;
+    }
+
+    rc = gnutls_x509_crt_get_version(crt);
+    if (rc < 0) {
+        error_setg(errp, "Failed to get certificate version: %s", gnutls_strerror(rc));
+        goto cleanup;
+    }
+
+    ret = rc;
+
+cleanup:
+    gnutls_x509_crt_deinit(crt);
+    return ret;
+}
+
+int qcrypto_x509_check_cert_times(uint8_t *cert, size_t size, Error **errp)
+{
+    int rc;
+    int ret = -1;
+    gnutls_x509_crt_t crt;
+    gnutls_datum_t datum = {.data = cert, .size = size};
+    time_t now = time(0);
+    time_t exp_time;
+    time_t act_time;
+
+    if (now == ((time_t)-1)) {
+        error_setg_errno(errp, errno, "Cannot get current time");
+        return ret;
+    }
+
+    rc = gnutls_x509_crt_init(&crt);
+    if (rc < 0) {
+        error_setg(errp, "Failed to initialize certificate: %s", gnutls_strerror(rc));
+        return ret;
+    }
+
+    rc = gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM);
+    if (rc != 0) {
+        error_setg(errp, "Failed to import certificate: %s", gnutls_strerror(rc));
+        goto cleanup;
+    }
+
+    exp_time = gnutls_x509_crt_get_expiration_time(crt);
+    if (exp_time == ((time_t)-1)) {
+        error_setg(errp, "Failed to get certificate expiration time");
+        goto cleanup;
+    }
+    if (exp_time < now) {
+        error_setg(errp, "The certificate has expired");
+        goto cleanup;
+    }
+
+    act_time = gnutls_x509_crt_get_activation_time(crt);
+    if (act_time == ((time_t)-1)) {
+        error_setg(errp, "Failed to get certificate activation time");
+        goto cleanup;
+    }
+    if (act_time > now) {
+        error_setg(errp, "The certificate is not yet active");
+        goto cleanup;
+    }
+
+    ret = 0;
+
+cleanup:
+    gnutls_x509_crt_deinit(crt);
+    return ret;
+}
+
+int qcrypto_x509_get_pk_algorithm(uint8_t *cert, size_t size, Error **errp)
+{
+    int rc;
+    int ret = -1;
+    unsigned int bits;
+    gnutls_x509_crt_t crt;
+    gnutls_datum_t datum = {.data = cert, .size = size};
+
+    rc = gnutls_x509_crt_init(&crt);
+    if (rc < 0) {
+        error_setg(errp, "Failed to initialize certificate: %s", gnutls_strerror(rc));
+        return ret;
+    }
+
+    rc = gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM);
+    if (rc != 0) {
+        error_setg(errp, "Failed to import certificate: %s", gnutls_strerror(rc));
+        goto cleanup;
+    }
+
+    rc = gnutls_x509_crt_get_pk_algorithm(crt, &bits);
+    if (rc >= G_N_ELEMENTS(gnutls_to_qcrypto_pk_alg_map)) {
+        error_setg(errp, "Unknown public key algorithm %d", rc);
+        goto cleanup;
+    }
+
+    ret = gnutls_to_qcrypto_pk_alg_map[rc];
+
+cleanup:
+    gnutls_x509_crt_deinit(crt);
+    return ret;
+}
+
+int qcrypto_x509_get_cert_key_id(uint8_t *cert, size_t size,
+                                 QCryptoKeyidFlags flag,
+                                 uint8_t **result,
+                                 size_t *resultlen,
+                                 Error **errp)
+{
+    int rc;
+    int ret = -1;
+    gnutls_x509_crt_t crt;
+    gnutls_datum_t datum = {.data = cert, .size = size};
+
+    *resultlen = qcrypto_x509_get_keyid_len(qcrypto_to_gnutls_keyid_flags_map[flag],
+                                            errp);
+    if (*resultlen == -1) {
+        return ret;
+    }
+
+    rc = gnutls_x509_crt_init(&crt);
+    if (rc < 0) {
+        error_setg(errp, "Failed to initialize certificate: %s", gnutls_strerror(rc));
+        return ret;
+    }
+
+    rc = gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM);
+    if (rc != 0) {
+        error_setg(errp, "Failed to import certificate: %s", gnutls_strerror(rc));
+        goto cleanup;
+    }
+
+    *result = g_malloc0(*resultlen);
+    if (gnutls_x509_crt_get_key_id(crt,
+                                   qcrypto_to_gnutls_keyid_flags_map[flag],
+                                   *result, resultlen) != 0) {
+        error_setg(errp, "Failed to get key ID from certificate");
+        goto cleanup;
+    }
+
+    ret = 0;
+
+cleanup:
+    gnutls_x509_crt_deinit(crt);
+    return ret;
+}
+
 #else /* ! CONFIG_GNUTLS */
 
 int qcrypto_x509_convert_cert_der(uint8_t *cert, size_t size,
@@ -228,4 +399,32 @@ int qcrypto_x509_get_signature_algorithm(uint8_t *cert, size_t size, Error **err
     return -1;
 }
 
+int qcrypto_x509_get_cert_version(uint8_t *cert, size_t size, Error **errp)
+{
+    error_setg(errp, "GNUTLS is required to get certificate version");
+    return -1;
+}
+
+int qcrypto_x509_check_cert_times(uint8_t *cert, size_t size, Error **errp)
+{
+    error_setg(errp, "GNUTLS is required to get certificate times");
+    return -1;
+}
+
+int qcrypto_x509_get_pk_algorithm(uint8_t *cert, size_t size, Error **errp)
+{
+    error_setg(errp, "GNUTLS is required to get public key algorithm");
+    return -1;
+}
+
+int qcrypto_x509_get_cert_key_id(uint8_t *cert, size_t size,
+                                 QCryptoKeyidFlags flag,
+                                 uint8_t **result,
+                                 size_t *resultlen,
+                                 Error **errp)
+{
+    error_setg(errp, "GNUTLS is required to get key ID");
+    return -1;
+}
+
 #endif /* ! CONFIG_GNUTLS */
diff --git a/include/crypto/x509-utils.h b/include/crypto/x509-utils.h
index d916d248bb..c122df0a98 100644
--- a/include/crypto/x509-utils.h
+++ b/include/crypto/x509-utils.h
@@ -40,6 +40,14 @@ typedef enum {
     QCRYPTO_SIG_ALGO_ECDSA_SHA512,
 } QCryptoSigAlgo;
 
+typedef enum {
+    QCRYPTO_PK_ALGO_UNKNOWN,
+    QCRYPTO_PK_ALGO_RSA,
+    QCRYPTO_PK_ALGO_DSA,
+    QCRYPTO_PK_ALGO_DH,
+    QCRYPTO_PK_ALGO_ECDSA,
+} QCryptoPkAlgo;
+
 int qcrypto_get_x509_cert_fingerprint(uint8_t *cert, size_t size,
                                       QCryptoHashAlgo hash,
                                       uint8_t *result,
@@ -53,10 +61,10 @@ int qcrypto_get_x509_cert_fingerprint(uint8_t *cert, size_t size,
  * @result: output location for the allocated buffer for the certificate in DER format
             (the function allocates memory which must be freed by the caller)
  * @resultlen: pointer to the size of the buffer
-               (will be replaced by the actual size of the DER-encoded certificate)
+               (will be updated with the actual size of the DER-encoded certificate)
  * @errp: error pointer
  *
- * Convert given @cert from PEM to DER format.
+ * Convert the given @cert from PEM to DER format.
  *
  * Returns: 0 on success,
  *         -1 on error.
@@ -70,7 +78,7 @@ int qcrypto_x509_convert_cert_der(uint8_t *cert, size_t size,
  * qcrypto_x509_get_keyid_len
  * @flag: the key ID flag
  *
- * Determine the length of the key ID of the given @flag.
+ * Determine the length of the key ID corresponding to the given @flag.
  *
  * Returns: the length on success,
  *          -1 on error.
@@ -90,4 +98,66 @@ int qcrypto_x509_get_keyid_len(QCryptoKeyidFlags flag, Error **errp);
  */
 int qcrypto_x509_get_signature_algorithm(uint8_t *cert, size_t size, Error **errp);
 
+/**
+ * qcrypto_x509_get_cert_version
+ * @cert: pointer to the raw certificate data
+ * @size: size of the certificate
+ * @errp: error pointer
+ *
+ * Determine the version of the @cert.
+ *
+ * Returns: the version on success,
+ *          -1 on error.
+ */
+int qcrypto_x509_get_cert_version(uint8_t *cert, size_t size, Error **errp);
+
+/**
+ * qcrypto_x509_check_cert_times
+ * @cert: pointer to the raw certificate data
+ * @size: size of the certificate
+ * @errp: error pointer
+ *
+ * Check whether the activation and expiration times of @cert
+ * are valid at the current time.
+ *
+ * Returns: 0 if the certificate times are valid,
+ *         -1 on error.
+ */
+int qcrypto_x509_check_cert_times(uint8_t *cert, size_t size, Error **errp);
+
+/**
+ * qcrypto_x509_get_pk_algorithm
+ * @cert: pointer to the raw certificate data
+ * @size: size of the certificate
+ * @errp: error pointer
+ *
+ * Determine the public key algorithm of the @cert.
+ *
+ * Returns: a value from the QCryptoPkAlgo enum on success,
+ *          -1 on error.
+ */
+int qcrypto_x509_get_pk_algorithm(uint8_t *cert, size_t size, Error **errp);
+
+/**
+ * qcrypto_x509_get_cert_key_id
+ * @cert: pointer to the raw certificate data
+ * @size: size of the certificate
+ * @flag: the key ID flag
+ * @result: output location for the allocated buffer for key ID
+            (the function allocates memory which must be freed by the caller)
+ * @resultlen: pointer to the size of the buffer
+               (will be updated with the actual size of key id)
+ * @errp: error pointer
+ *
+ * Retrieve the key ID from the @cert based on the specified @flag.
+ *
+ * Returns: 0 if key ID was successfully stored in @result,
+ *         -1 on error.
+ */
+int qcrypto_x509_get_cert_key_id(uint8_t *cert, size_t size,
+                                 QCryptoKeyidFlags flag,
+                                 uint8_t **result,
+                                 size_t *resultlen,
+                                 Error **errp);
+
 #endif
-- 
2.49.0