Introduce helper functions to support signature verification required by
DIAG 508 subcode 1:
qcrypto_pkcs7_convert_sig_pem() – converts a signature from DER to PEM format
qcrypto_x509_verify_sig() – verifies the provided data against the given signature
These functions enable basic signature verification support.
Signed-off-by: Zhuoying Cai <zycai@linux.ibm.com>
---
crypto/x509-utils.c | 108 ++++++++++++++++++++++++++++++++++++
include/crypto/x509-utils.h | 39 +++++++++++++
2 files changed, 147 insertions(+)
diff --git a/crypto/x509-utils.c b/crypto/x509-utils.c
index 67b42aad1f..f582e2ee48 100644
--- a/crypto/x509-utils.c
+++ b/crypto/x509-utils.c
@@ -16,6 +16,7 @@
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
#include <gnutls/x509.h>
+#include <gnutls/pkcs7.h>
static const int qcrypto_to_gnutls_hash_alg_map[QCRYPTO_HASH_ALGO__MAX] = {
[QCRYPTO_HASH_ALGO_MD5] = GNUTLS_DIG_MD5,
@@ -275,6 +276,96 @@ cleanup:
return ret;
}
+int qcrypto_pkcs7_convert_sig_pem(uint8_t *sig, size_t sig_size,
+ uint8_t **result, size_t *resultlen,
+ Error **errp)
+{
+ int ret = -1;
+ int rc;
+ gnutls_pkcs7_t signature;
+ gnutls_datum_t sig_datum_der = {.data = sig, .size = sig_size};
+ gnutls_datum_t sig_datum_pem = { 0, };
+
+ rc = gnutls_pkcs7_init(&signature);
+ if (rc < 0) {
+ error_setg(errp, "Failed to initalize pkcs7 data: %s", gnutls_strerror(rc));
+ return ret;
+ }
+
+ rc = gnutls_pkcs7_import(signature, &sig_datum_der, GNUTLS_X509_FMT_DER);
+ if (rc != 0) {
+ error_setg(errp, "Failed to import signature: %s", gnutls_strerror(rc));
+ goto cleanup;
+ }
+
+ rc = gnutls_pkcs7_export2(signature, GNUTLS_X509_FMT_PEM, &sig_datum_pem);
+ if (rc != 0) {
+ error_setg(errp, "Failed to convert signature to PEM format: %s",
+ gnutls_strerror(rc));
+ gnutls_free(sig_datum_pem.data);
+ goto cleanup;
+ }
+
+ *result = g_steal_pointer(&sig_datum_pem.data);
+ *resultlen = sig_datum_pem.size;
+
+ ret = 0;
+
+cleanup:
+ gnutls_pkcs7_deinit(signature);
+ return ret;
+}
+
+int qcrypto_x509_verify_sig(uint8_t *cert, size_t cert_size,
+ uint8_t *comp, size_t comp_size,
+ uint8_t *sig, size_t sig_size, Error **errp)
+{
+ int rc;
+ int ret = -1;
+ gnutls_x509_crt_t crt = NULL;
+ gnutls_pkcs7_t signature = NULL;
+ gnutls_datum_t cert_datum = {.data = cert, .size = cert_size};
+ gnutls_datum_t data_datum = {.data = comp, .size = comp_size};
+ gnutls_datum_t sig_datum = {.data = sig, .size = sig_size};
+
+ rc = gnutls_x509_crt_init(&crt);
+ if (rc < 0) {
+ error_setg(errp, "Failed to initialize certificate: %s", gnutls_strerror(rc));
+ goto cleanup;
+ }
+
+ rc = gnutls_x509_crt_import(crt, &cert_datum, GNUTLS_X509_FMT_PEM);
+ if (rc != 0) {
+ error_setg(errp, "Failed to import certificate: %s", gnutls_strerror(rc));
+ goto cleanup;
+ }
+
+ rc = gnutls_pkcs7_init(&signature);
+ if (rc < 0) {
+ error_setg(errp, "Failed to initalize pkcs7 data: %s", gnutls_strerror(rc));
+ goto cleanup;
+ }
+
+ rc = gnutls_pkcs7_import(signature, &sig_datum , GNUTLS_X509_FMT_PEM);
+ if (rc != 0) {
+ error_setg(errp, "Failed to import signature: %s", gnutls_strerror(rc));
+ goto cleanup;
+ }
+
+ rc = gnutls_pkcs7_verify_direct(signature, crt, 0, &data_datum, 0);
+ if (rc != 0) {
+ error_setg(errp, "Failed to verify signature: %s", gnutls_strerror(rc));
+ goto cleanup;
+ }
+
+ ret = 0;
+
+cleanup:
+ gnutls_x509_crt_deinit(crt);
+ gnutls_pkcs7_deinit(signature);
+ return ret;
+}
+
#else /* ! CONFIG_GNUTLS */
int qcrypto_get_x509_cert_fingerprint(uint8_t *cert, size_t size,
@@ -318,4 +409,21 @@ int qcrypto_x509_get_cert_key_id(uint8_t *cert, size_t size,
return -1;
}
+int qcrypto_pkcs7_convert_sig_pem(uint8_t *sig, size_t sig_size,
+ uint8_t **result,
+ size_t *resultlen,
+ Error **errp)
+{
+ error_setg(errp, "GNUTLS is required to export pkcs7 signature");
+ return -1;
+}
+
+int qcrypto_x509_verify_sig(uint8_t *cert, size_t cert_size,
+ uint8_t *comp, size_t comp_size,
+ uint8_t *sig, size_t sig_size, Error **errp)
+{
+ error_setg(errp, "GNUTLS is required for signature-verification support");
+ return -1;
+}
+
#endif /* ! CONFIG_GNUTLS */
diff --git a/include/crypto/x509-utils.h b/include/crypto/x509-utils.h
index f169df81cb..c4073fd265 100644
--- a/include/crypto/x509-utils.h
+++ b/include/crypto/x509-utils.h
@@ -97,4 +97,43 @@ int qcrypto_x509_get_cert_key_id(uint8_t *cert, size_t size,
size_t *resultlen,
Error **errp);
+/**
+ * qcrypto_pkcs7_convert_sig_pem
+ * @sig: pointer to the PKCS#7 signature in DER format
+ * @sig_size: size of the signature
+ * @result: output location for the allocated buffer for the signature in PEM format
+ (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 the PEM-encoded signature)
+ * @errp: error pointer
+ *
+ * Convert given PKCS#7 @sig from DER to PEM format.
+ *
+ * Returns: 0 if PEM-encoded signature was successfully stored in @result,
+ * -1 on error.
+ */
+int qcrypto_pkcs7_convert_sig_pem(uint8_t *sig, size_t sig_size,
+ uint8_t **result,
+ size_t *resultlen,
+ Error **errp);
+
+/**
+ * qcrypto_x509_verify_sig
+ * @cert: pointer to the raw certificate data
+ * @cert_size: size of the certificate
+ * @comp: pointer to the component to be verified
+ * @comp_size: size of the component
+ * @sig: pointer to the signature
+ * @sig_size: size of the signature
+ * @errp: error pointer
+ *
+ * Verify the provided @comp against the @sig and @cert.
+ *
+ * Returns: 0 on success,
+ * -1 on error.
+ */
+int qcrypto_x509_verify_sig(uint8_t *cert, size_t cert_size,
+ uint8_t *comp, size_t comp_size,
+ uint8_t *sig, size_t sig_size, Error **errp);
+
#endif
--
2.50.1