On Tue, Dec 09, 2025 at 01:22:31 +0530, Arun Menon via Devel wrote:
Now that we have the functionality to provide the secrets driver with an encryption key through a configuration file or using system credentials, and the newly introduced attribute to iterate over the encryption schemes, we can use the key to save and load secrets.
Encrypt all secrets that are going to be saved on the disk if the 'secrets_encryption_key' path is set in the secret.conf file OR if a valid systemd generated credential exists.
While loading secrets, identify the decryption method by matching the file extension of the stored secret against the known encryptionSchemeType values. If no matching scheme is found, the secret is skipped. If the encryption key is changed across restarts, then also the secret driver will fail to load the secrets from the disk that were encrypted with the former key.
Signed-off-by: Arun Menon <armenon@redhat.com> --- src/conf/virsecretobj.c | 166 ++++++++++++++++++++++++++++++------- src/conf/virsecretobj.h | 18 +++- src/secret/secret_driver.c | 25 ++++-- 3 files changed, 169 insertions(+), 40 deletions(-)
diff --git a/src/conf/virsecretobj.c b/src/conf/virsecretobj.c index a3dd7983bb..60a1323625 100644 --- a/src/conf/virsecretobj.c +++ b/src/conf/virsecretobj.c @@ -31,6 +31,10 @@ #include "virhash.h" #include "virlog.h" #include "virstring.h" +#include "virsecret.h" +#include "virrandom.h" +#include "vircrypto.h" +#include "virsecureerase.h"
#define VIR_FROM_THIS VIR_FROM_SECRET
@@ -45,6 +49,16 @@ struct _virSecretObj { size_t value_size; };
+typedef struct _virSecretSchemeInfo { + const char *suffix; + virCryptoCipher cipher; +} virSecretSchemeInfo; + +virSecretSchemeInfo schemeInfo[] = { + { ".base64", -1 }, + { ".aes256cbc", VIR_CRYPTO_CIPHER_AES256CBC },
If you order the entries in this struct the other way around you'll not have to use VIR_SECRET_ENCRYPTION_SCHEME_LAST - 1 everywhere. In fact you won't even need the virSecretEncryptionScheme type at all.
+}; + static virClass *virSecretObjClass; static virClass *virSecretObjListClass; static void virSecretObjDispose(void *obj); @@ -323,7 +337,8 @@ virSecretObj * virSecretObjListAdd(virSecretObjList *secrets, virSecretDef **newdef, const char *configDir, - virSecretDef **oldDef) + virSecretDef **oldDef, + bool encryptData) { virSecretObj *obj; virSecretDef *objdef; @@ -363,6 +378,8 @@ virSecretObjListAdd(virSecretObjList *secrets, } else { /* No existing secret with same UUID, * try look for matching usage instead */ + const char *secretSuffix = ".base64"; + g_autofree char *encryptionSchemeSuffix = NULL; if ((obj = virSecretObjListFindByUsageLocked(secrets, (*newdef)->usage_type, (*newdef)->usage_id))) { @@ -379,10 +396,17 @@ virSecretObjListAdd(virSecretObjList *secrets, goto cleanup;
/* Generate the possible configFile and secretValueFile strings - * using the configDir, uuidstr, and appropriate suffix + * using the configDir, uuidstr, and appropriate suffix. + * By default, the latest encryption cipher will be used to encrypt secrets. */ + + if (encryptData) { + encryptionSchemeSuffix = g_strdup_printf(".%s", virSecretEncryptionSchemeTypeToString(VIR_SECRET_ENCRYPTION_SCHEME_LAST- 1));
use schemeinfo[0].suffix and you won't have to copy these any more.
+ } else { + encryptionSchemeSuffix = g_strdup(secretSuffix); + } if (!(obj->configFile = virFileBuildPath(configDir, uuidstr, ".xml")) || - !(obj->secretValueFile = virFileBuildPath(configDir, uuidstr, ".base64"))) + !(obj->secretValueFile = virFileBuildPath(configDir, uuidstr, encryptionSchemeSuffix))) goto cleanup;
if (virHashAddEntry(secrets->objs, uuidstr, obj) < 0) @@ -682,15 +706,40 @@ virSecretObjSaveConfig(virSecretObj *obj)
int -virSecretObjSaveData(virSecretObj *obj) +virSecretObjSaveData(virSecretObj *obj, + bool encryptData, + uint8_t *secretsEncryptionKey, + size_t secretsKeyLen) { g_autofree char *base64 = NULL; + g_autofree uint8_t *secret = NULL; + g_autofree uint8_t *encryptedValue = NULL; + size_t encryptedValueLen = 0; + size_t secretLen = 0; + uint8_t iv[16] = { 0 };
if (!obj->value) return 0;
- base64 = g_base64_encode(obj->value, obj->value_size); - + if (encryptData && secretsEncryptionKey) { + if (virRandomBytes(iv, sizeof(iv)) < 0) { + return -1; + } + if (virCryptoEncryptData(VIR_CRYPTO_CIPHER_LAST-1,
Umm so this is a 3rd distinct way how you specify AES in this series. use the entry from the struct instead so that there isn't multiple places that'll need to be changed if a different one is to be picked.
+ secretsEncryptionKey, secretsKeyLen, + iv, sizeof(iv), + (uint8_t *)obj->value, obj->value_size, + &encryptedValue, &encryptedValueLen) < 0) { + return -1; + } + secretLen = sizeof(iv) + encryptedValueLen; + secret = g_new0(uint8_t, secretLen); + memcpy(secret, iv, sizeof(iv)); + memcpy(secret + sizeof(iv), encryptedValue, encryptedValueLen); + base64 = g_base64_encode(secret, secretLen); + } else { + base64 = g_base64_encode(obj->value, obj->value_size); + } if (virFileRewriteStr(obj->secretValueFile, S_IRUSR | S_IWUSR, base64) < 0) return -1;
[...]
@@ -807,11 +862,24 @@ virSecretLoadValidateUUID(virSecretDef *def,
static int -virSecretLoadValue(virSecretObj *obj) +virSecretLoadValue(virSecretObj *obj, + uint8_t *secretsEncryptionKey, + size_t secretsKeyLen) { - int ret = -1, fd = -1; + int ret = -1; + VIR_AUTOCLOSE fd = -1; struct stat st; + size_t i; + g_autofree char *contents = NULL; + g_autofree uint8_t *contents_encrypted = NULL; + g_autofree uint8_t *decryptedValue = NULL;
Mix of snake-case and camel case
+ g_autofree char *encryptionScheme = NULL;
This variable is unused.
+ + size_t decryptedValueLen = 0; + uint8_t iv[16] = { 0 }; + uint8_t *ciphertext = NULL; + size_t ciphertextLen = 0;
if ((fd = open(obj->secretValueFile, O_RDONLY)) == -1) { if (errno == ENOENT) { @@ -841,25 +909,52 @@ virSecretLoadValue(virSecretObj *obj) goto cleanup; }
- contents = g_new0(char, st.st_size + 1); - - if (saferead(fd, contents, st.st_size) != st.st_size) { - virReportSystemError(errno, _("cannot read '%1$s'"), - obj->secretValueFile); - goto cleanup; + /* Iterate over the encryption schemes and decrypt the contents + * of the file on the disk, by matching the file extension with the encryption + * scheme. + * If there is no scheme matching the file extension, then that secret is not loaded. */ + + for (i = 0; i < G_N_ELEMENTS(schemeInfo); i++) { + if (virStringHasSuffix(obj->secretValueFile, schemeInfo[i].suffix)) { + contents = g_new0(char, st.st_size + 1); + if (saferead(fd, contents, st.st_size) != st.st_size) { + virReportSystemError(errno, _("cannot read '%1$s'"), + obj->secretValueFile); + goto cleanup; + } + contents[st.st_size] = '\0'; + if (schemeInfo[i].cipher != -1) { + contents_encrypted = g_base64_decode(contents, &obj->value_size); + if (sizeof(iv) > obj->value_size) { + virReportError(VIR_ERR_INVALID_SECRET, + _("Encrypted secret size '%1$zu' is invalid"), + obj->value_size); + goto cleanup; + } + memcpy(iv, contents_encrypted, sizeof(iv)); + ciphertext = contents_encrypted + sizeof(iv); + ciphertextLen = st.st_size - sizeof(iv); + if (virCryptoDecryptData(schemeInfo[i].cipher, + secretsEncryptionKey, secretsKeyLen, + iv, sizeof(iv), + ciphertext, ciphertextLen, + &decryptedValue, &decryptedValueLen) < 0) { + goto cleanup; + } + g_free(obj->value); + obj->value = g_steal_pointer(&decryptedValue); + obj->value_size = decryptedValueLen; + } else { + obj->value = g_base64_decode(contents, &obj->value_size); + } + break; + } } - contents[st.st_size] = '\0'; - - VIR_FORCE_CLOSE(fd); - - obj->value = g_base64_decode(contents, &obj->value_size); - ret = 0; - cleanup: - if (contents != NULL) - memset(contents, 0, st.st_size); - VIR_FORCE_CLOSE(fd); + virSecureErase(contents_encrypted, obj->value_size); + virSecureErase(contents, st.st_size); + virSecureErase(iv, sizeof(iv)); return ret; }
diff --git a/src/secret/secret_driver.c b/src/secret/secret_driver.c index 408a629ea0..8c0796c86a 100644 --- a/src/secret/secret_driver.c +++ b/src/secret/secret_driver.c @@ -30,6 +30,7 @@ #include "virlog.h" #include "viralloc.h" #include "secret_conf.h" +#include "secret_config.h"
This likely fixes the build issue from 3/5.
#include "virsecretobj.h" #include "secret_driver.h" #include "virthread.h"