sss_idmap: add support for samba struct dom_sid

The samba ndr libraries use struct dom_sid to handle SIDs. Since there
is no public samba library which offers conversion from other
representations, e.g. as string, this is added to libsss_idmap.
To avoid compile-time or run-time dependency to any samba library or
header file the definition of the struct is copied here.

3 files changed, 305 insertions, 0 deletions

diff --git a/src/lib/idmap/sss_idmap.h b/src/lib/idmap/sss_idmap.h
index a3ec919c..6b7cbe50 100644
--- a/src/lib/idmap/sss_idmap.h
+++ b/src/lib/idmap/sss_idmap.h
@@ -98,6 +98,13 @@ struct sss_dom_sid;
 struct sss_idmap_ctx;
 
 /**
+ * Placeholder for Samba's struct dom_sid. Consumers of libsss_idmap should
+ * include an appropriate Samba header file to define struct dom_sid. We use
+ * it here to avoid a hard dependency on Samba devel packages.
+ */
+struct dom_sid;
+
+/**
  * @brief Initialize idmap context
  *
  * @param[in] alloc_func Function to allocate memory for the context, if
@@ -375,6 +382,106 @@ enum idmap_error_code sss_idmap_dom_sid_to_sid(struct sss_idmap_ctx *ctx,
 enum idmap_error_code sss_idmap_sid_to_dom_sid(struct sss_idmap_ctx *ctx,
                                                const char *sid,
                                                struct sss_dom_sid **dom_sid);
+
+/**
+ * @brief Convert SID string to Samba dom_sid structure
+ *
+ * @param[in] ctx       Idmap context
+ * @param[in] sid       Zero-terminated string representation of the SID
+ * @param[out] smb_sid  Samba dom_sid structure,
+ *                      must be freed if not needed anymore
+ *
+ * @return
+ *  - #IDMAP_SID_INVALID: Given SID is invalid
+ *  - #IDMAP_OUT_OF_MEMORY: Failed to allocate memory for the result
+ */
+enum idmap_error_code sss_idmap_sid_to_smb_sid(struct sss_idmap_ctx *ctx,
+                                               const char *sid,
+                                               struct dom_sid **smb_sid);
+
+/**
+ * @brief Convert Samba dom_sid structure to SID string
+ *
+ * @param[in] ctx       Idmap context
+ * @param[in] smb_sid   Samba dom_sid structure
+ * @param[out] sid      Zero-terminated string representation of the SID,
+ *                      must be freed if not needed anymore
+ *
+ * @return
+ *  - #IDMAP_SID_INVALID: Given SID is invalid
+ *  - #IDMAP_OUT_OF_MEMORY: Failed to allocate memory for the result
+ */
+enum idmap_error_code sss_idmap_smb_sid_to_sid(struct sss_idmap_ctx *ctx,
+                                               struct dom_sid *smb_sid,
+                                               char **sid);
+
+/**
+ * @brief Convert SID stucture to Samba dom_sid structure
+ *
+ * @param[in] ctx       Idmap context
+ * @param[in] dom_sid   SID structure
+ * @param[out] smb_sid  Samba dom_sid structure,
+ *                      must be freed if not needed anymore
+ *
+ * @return
+ *  - #IDMAP_SID_INVALID: Given SID is invalid
+ *  - #IDMAP_OUT_OF_MEMORY: Failed to allocate memory for the result
+ */
+enum idmap_error_code sss_idmap_dom_sid_to_smb_sid(struct sss_idmap_ctx *ctx,
+                                                   struct sss_dom_sid *dom_sid,
+                                                   struct dom_sid **smb_sid);
+
+/**
+ * @brief Convert Samba dom_sid structure to SID structure
+ *
+ * @param[in] ctx       Idmap context
+ * @param[in] smb_sid   Samba dom_sid structure
+ * @param[out] dom_sid  SID structure,
+ *                      must be freed if not needed anymore
+ *
+ * @return
+ *  - #IDMAP_SID_INVALID: Given SID is invalid
+ *  - #IDMAP_OUT_OF_MEMORY: Failed to allocate memory for the result
+ */
+enum idmap_error_code sss_idmap_smb_sid_to_dom_sid(struct sss_idmap_ctx *ctx,
+                                                   struct dom_sid *smb_sid,
+                                                   struct sss_dom_sid **dom_sid);
+
+/**
+ * @brief Convert binary SID to Samba dom_sid structure
+ *
+ * @param[in] ctx       Idmap context
+ * @param[in] bin_sid   Array with the binary SID
+ * @param[in] length    Size of the array containing the binary SID
+ * @param[out] smb_sid  Samba dom_sid structure,
+ *                      must be freed if not needed anymore
+ *
+ * @return
+ *  - #IDMAP_SID_INVALID: Given SID is invalid
+ *  - #IDMAP_OUT_OF_MEMORY: Failed to allocate memory for the result
+ */
+enum idmap_error_code sss_idmap_bin_sid_to_smb_sid(struct sss_idmap_ctx *ctx,
+                                                   const uint8_t *bin_sid,
+                                                   size_t length,
+                                                   struct dom_sid **smb_sid);
+
+/**
+ * @brief Convert Samba dom_sid structure to binary SID
+ *
+ * @param[in] ctx       Idmap context
+ * @param[in] smb_sid   Samba dom_sid structure
+ * @param[out] bin_sid  Array with the binary SID,
+ *                      must be freed if not needed anymore
+ * @param[out] length   Size of the array containing the binary SID
+ *
+ * @return
+ *  - #IDMAP_SID_INVALID: Given SID is invalid
+ *  - #IDMAP_OUT_OF_MEMORY: Failed to allocate memory for the result
+ */
+enum idmap_error_code sss_idmap_smb_sid_to_bin_sid(struct sss_idmap_ctx *ctx,
+                                                   struct dom_sid *smb_sid,
+                                                   uint8_t **bin_sid,
+                                                   size_t *length);
 /**
  * @}
  */
diff --git a/src/lib/idmap/sss_idmap_conv.c b/src/lib/idmap/sss_idmap_conv.c
index df96fcc3..1d3ffb3b 100644
--- a/src/lib/idmap/sss_idmap_conv.c
+++ b/src/lib/idmap/sss_idmap_conv.c
@@ -59,6 +59,7 @@ enum idmap_error_code sss_idmap_bin_sid_to_dom_sid(struct sss_idmap_ctx *ctx,
     if (dom_sid == NULL) {
         return IDMAP_OUT_OF_MEMORY;
     }
+    memset(dom_sid, 0, sizeof(struct sss_dom_sid));
 
     /* Safely copy in the SID revision number */
     dom_sid->sid_rev_num = (uint8_t) *(bin_sid + p);
@@ -387,3 +388,181 @@ done:
 
     return err;
 }
+
+enum idmap_error_code sss_idmap_sid_to_smb_sid(struct sss_idmap_ctx *ctx,
+                                               const char *sid,
+                                               struct dom_sid **_smb_sid)
+{
+    enum idmap_error_code err;
+    struct sss_dom_sid *dom_sid = NULL;
+    struct dom_sid *smb_sid = NULL;
+
+    err = sss_idmap_sid_to_dom_sid(ctx, sid, &dom_sid);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    err = sss_idmap_dom_sid_to_smb_sid(ctx, dom_sid, &smb_sid);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    *_smb_sid = smb_sid;
+    err = IDMAP_SUCCESS;
+
+done:
+    ctx->free_func(dom_sid, ctx->alloc_pvt);
+    if (err != IDMAP_SUCCESS) {
+        ctx->free_func(smb_sid, ctx->alloc_pvt);
+    }
+
+    return err;
+}
+
+enum idmap_error_code sss_idmap_smb_sid_to_sid(struct sss_idmap_ctx *ctx,
+                                               struct dom_sid *smb_sid,
+                                               char **_sid)
+{
+    enum idmap_error_code err;
+    struct sss_dom_sid *dom_sid = NULL;
+    char *sid = NULL;
+
+    err = sss_idmap_smb_sid_to_dom_sid(ctx, smb_sid, &dom_sid);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    err = sss_idmap_dom_sid_to_sid(ctx, dom_sid, &sid);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    *_sid = sid;
+    err = IDMAP_SUCCESS;
+
+done:
+    ctx->free_func(dom_sid, ctx->alloc_pvt);
+    if (err != IDMAP_SUCCESS) {
+        ctx->free_func(sid, ctx->alloc_pvt);
+    }
+
+    return err;
+}
+
+enum idmap_error_code sss_idmap_dom_sid_to_smb_sid(struct sss_idmap_ctx *ctx,
+                                                   struct sss_dom_sid *dom_sid,
+                                                   struct dom_sid **_smb_sid)
+{
+    struct dom_sid *smb_sid;
+    size_t c;
+
+    smb_sid = ctx->alloc_func(sizeof(struct dom_sid), ctx->alloc_pvt);
+    if (smb_sid == NULL) {
+        return IDMAP_OUT_OF_MEMORY;
+    }
+    memset(smb_sid, 0, sizeof(struct dom_sid));
+
+    smb_sid->sid_rev_num = dom_sid->sid_rev_num;
+    smb_sid->num_auths = dom_sid->num_auths;
+    for (c = 0; c < SID_ID_AUTHS; c++) {
+        smb_sid->id_auth[c] = dom_sid->id_auth[c];
+    }
+    for (c = 0; c < SID_SUB_AUTHS; c++) {
+        smb_sid->sub_auths[c] = dom_sid->sub_auths[c];
+    }
+
+    *_smb_sid = smb_sid;
+
+    return IDMAP_SUCCESS;
+}
+
+enum idmap_error_code sss_idmap_smb_sid_to_dom_sid(struct sss_idmap_ctx *ctx,
+                                                   struct dom_sid *smb_sid,
+                                                   struct sss_dom_sid **_dom_sid)
+{
+    struct sss_dom_sid *dom_sid;
+    size_t c;
+
+    dom_sid = ctx->alloc_func(sizeof(struct sss_dom_sid), ctx->alloc_pvt);
+    if (dom_sid == NULL) {
+        return IDMAP_OUT_OF_MEMORY;
+    }
+    memset(dom_sid, 0, sizeof(struct sss_dom_sid));
+
+    dom_sid->sid_rev_num = smb_sid->sid_rev_num;
+    dom_sid->num_auths = smb_sid->num_auths;
+    for (c = 0; c < SID_ID_AUTHS; c++) {
+        dom_sid->id_auth[c] = smb_sid->id_auth[c];
+    }
+    for (c = 0; c < SID_SUB_AUTHS; c++) {
+        dom_sid->sub_auths[c] = smb_sid->sub_auths[c];
+    }
+
+    *_dom_sid = dom_sid;
+
+    return IDMAP_SUCCESS;
+}
+
+enum idmap_error_code sss_idmap_bin_sid_to_smb_sid(struct sss_idmap_ctx *ctx,
+                                                   const uint8_t *bin_sid,
+                                                   size_t length,
+                                                   struct dom_sid **_smb_sid)
+{
+    enum idmap_error_code err;
+    struct sss_dom_sid *dom_sid = NULL;
+    struct dom_sid *smb_sid = NULL;
+
+    err = sss_idmap_bin_sid_to_dom_sid(ctx, bin_sid, length, &dom_sid);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    err = sss_idmap_dom_sid_to_smb_sid(ctx, dom_sid, &smb_sid);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    *_smb_sid = smb_sid;
+    err = IDMAP_SUCCESS;
+
+done:
+    ctx->free_func(dom_sid, ctx->alloc_pvt);
+    if (err != IDMAP_SUCCESS) {
+        ctx->free_func(smb_sid, ctx->alloc_pvt);
+    }
+
+    return err;
+}
+
+enum idmap_error_code sss_idmap_smb_sid_to_bin_sid(struct sss_idmap_ctx *ctx,
+                                                   struct dom_sid *smb_sid,
+                                                   uint8_t **_bin_sid,
+                                                   size_t *_length)
+{
+    enum idmap_error_code err;
+    struct sss_dom_sid *dom_sid = NULL;
+    uint8_t *bin_sid = NULL;
+    size_t length;
+
+    err = sss_idmap_smb_sid_to_dom_sid(ctx, smb_sid, &dom_sid);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    err = sss_idmap_dom_sid_to_bin_sid(ctx, dom_sid, &bin_sid, &length);
+    if (err != IDMAP_SUCCESS) {
+        goto done;
+    }
+
+    *_bin_sid = bin_sid;
+    *_length = length;
+    err = IDMAP_SUCCESS;
+
+done:
+    ctx->free_func(dom_sid, ctx->alloc_pvt);
+    if (err != IDMAP_SUCCESS) {
+        ctx->free_func(bin_sid, ctx->alloc_pvt);
+    }
+
+    return err;
+}
diff --git a/src/lib/idmap/sss_idmap_private.h b/src/lib/idmap/sss_idmap_private.h
index 776c56ab..bdb52895 100644
--- a/src/lib/idmap/sss_idmap_private.h
+++ b/src/lib/idmap/sss_idmap_private.h
@@ -38,4 +38,23 @@ struct sss_idmap_ctx {
     struct idmap_domain_info *idmap_domain_info;
 };
 
+/* This is a copy of the definition in the samba gen_ndr/security.h header
+ * file. We use it here to be able to offer conversions form struct dom_sid to
+ * string or binary representation since those are not made available by
+ * public samba libraries.
+ *
+ * If the definition ever changes on the samba side we have to adopt the
+ * change. But chances are very low that this will ever happen since e.g. this
+ * struct is also defined in public documentation from Microsoft. See e.g.
+ * section 2.4.2.3 of "[MS-DTYP]: Windows Data Types"
+ * http://msdn.microsoft.com/en-us/library/cc230364(v=prot.10)
+ */
+
+struct dom_sid {
+        uint8_t sid_rev_num;
+        int8_t num_auths;
+        uint8_t id_auth[6];
+        uint32_t sub_auths[15];
+};
+
 #endif /* SSS_IDMAP_PRIVATE_H_ */