Merge pull request #4913 from implausible/feature/signing-rebase-commits

Add sign capability to git_rebase_commit

2 files changed, 40 insertions, 2 deletions

diff --git a/include/git2/commit.h b/include/git2/commit.h
index 7e0409cc7..e6c4656a9 100644
--- a/include/git2/commit.h
+++ b/include/git2/commit.h
@@ -480,7 +480,8 @@ GIT_EXTERN(int) git_commit_create_buffer(
  *
  * @param out the resulting commit id
  * @param commit_content the content of the unsigned commit object
- * @param signature the signature to add to the commit
+ * @param signature the signature to add to the commit. Leave `NULL`
+ * to create a commit without adding a signature field.
  * @param signature_field which header field should contain this
  * signature. Leave `NULL` for the default of "gpgsig"
  * @return 0 or an error code
@@ -501,6 +502,27 @@ GIT_EXTERN(int) git_commit_create_with_signature(
  */
 GIT_EXTERN(int) git_commit_dup(git_commit **out, git_commit *source);
 
+/**
+ * Commit signing callback.
+ *
+ * The callback will be called with the commit content, giving a user an
+ * opportunity to sign the commit content. The signature_field
+ * buf may be left empty to specify the default field "gpgsig".
+ *
+ * Signatures can take the form of any string, and can be created on an arbitrary
+ * header field. Signatures are most commonly used for verifying authorship of a
+ * commit using GPG or a similar cryptographically secure signing algorithm.
+ * See https://git-scm.com/book/en/v2/Git-Tools-Signing-Your-Work for more
+ * details.
+ *
+ * When the callback:
+ * - returns GIT_PASSTHROUGH, no signature will be added to the commit.
+ * - returns < 0, commit creation will be aborted.
+ * - returns GIT_OK, the signature parameter is expected to be filled.
+ */
+typedef int (*git_commit_signing_cb)(
+	git_buf *signature, git_buf *signature_field, const char *commit_content, void *payload);
+
 /** @} */
 GIT_END_DECL
 #endif
diff --git a/include/git2/rebase.h b/include/git2/rebase.h
index 011d3e119..99a02fef9 100644
--- a/include/git2/rebase.h
+++ b/include/git2/rebase.h
@@ -13,6 +13,7 @@
 #include "annotated_commit.h"
 #include "merge.h"
 #include "checkout.h"
+#include "commit.h"
 
 /**
  * @file git2/rebase.h
@@ -72,6 +73,21 @@ typedef struct {
 	 * `abort` to match git semantics.
 	 */
 	git_checkout_options checkout_options;
+
+	/**
+	 * If provided, this will be called with the commit content, allowing
+	 * a signature to be added to the rebase commit. Can be skipped with
+	 * GIT_PASSTHROUGH. If GIT_PASSTHROUGH is returned, a commit will be made
+	 * without a signature.
+	 * This field is only used when performing git_rebase_commit.
+	 */
+	git_commit_signing_cb signing_cb;
+
+	/**
+	 * This will be passed to each of the callbacks in this struct
+	 * as the last parameter.
+	 */
+	void *payload;
 } git_rebase_options;
 
 /**
@@ -118,7 +134,7 @@ typedef enum {
 #define GIT_REBASE_OPTIONS_VERSION 1
 #define GIT_REBASE_OPTIONS_INIT \
 	{ GIT_REBASE_OPTIONS_VERSION, 0, 0, NULL, GIT_MERGE_OPTIONS_INIT, \
-	  GIT_CHECKOUT_OPTIONS_INIT}
+	  GIT_CHECKOUT_OPTIONS_INIT, NULL, NULL }
 
 /** Indicates that a rebase operation is not (yet) in progress. */
 #define GIT_REBASE_NO_OPERATION SIZE_MAX