Subject: [PATCH v4 4/5] merge/pull Check for untrusted good GPG signatures

From: Sebastian Götte <[email-masked]>
Date: Tue, 26 Mar 2013 12:05:50 +0100

When --verify-signatures is specified, abort the merge in case a good
GPG signature from an untrusted key is encountered.

Signed-off-by: Sebastian Götte <[email-masked]>
---
 builtin/merge.c                    |   2 ++
 commit.c                           |   2 ++
 commit.h                           |   9 +++++----
 gpg-interface.h                    |   2 +-
 t/lib-gpg/pubring.gpg              | Bin 1164 -> 2359 bytes
 t/lib-gpg/random_seed              | Bin 600 -> 600 bytes
 t/lib-gpg/secring.gpg              | Bin 1237 -> 3734 bytes
 t/lib-gpg/trustdb.gpg              | Bin 1280 -> 1360 bytes
 t/t7612-merge-verify-signatures.sh |   9 +++++++++
 9 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/builtin/merge.c b/builtin/merge.c
index 227040b..e3df36f 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1251,6 +1251,8 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 					if (verbosity >= 0)
 						printf(_("Commit %s has a good GPG signature by %s (key fingerprint %s)\n"), hex, signature.signer, signature.key);
 					break;
+				case 'U':
+					die(_("Commit %s has a good GPG signature allegedly by %s, albeit from an untrusted key (fingerprint %s)."), hex, signature.signer, signature.key);
 				case 'B':
 					die(_("Commit %s has a bad GPG signature allegedly by %s (key fingerprint %s)."), hex, signature.signer, signature.key);
 				default: /* 'N' */
diff --git a/commit.c b/commit.c
index 533727c..785eb51 100644
--- a/commit.c
+++ b/commit.c
@@ -1027,6 +1027,8 @@ static struct {
 	char result;
 	const char *check;
 } signature_check[] = {
+	{ 'U', "[GNUPG:] TRUST_UNDEFINED" },
+	{ 'U', "[GNUPG:] TRUST_NEVER" },
 	{ 'G', "[GNUPG:] GOODSIG " },
 	{ 'B', "[GNUPG:] BADSIG " },
 };
diff --git a/commit.h b/commit.h
index cf35472..c946135 100644
--- a/commit.h
+++ b/commit.h
@@ -232,10 +232,11 @@ extern void print_commit_list(struct commit_list *list,
 			      const char *format_last);
 
 /*
- * Check the signature of the given commit. The result of the check is stored in
- * sig->check_result, 'G' for a good signature, 'B' for a bad signature and 'N'
- * for no signature at all.
- * This may allocate memory for sig->gpg_output, sig->gpg_status, sig->signer and sig->key.
+ * Check the signature of the given commit. The result of the check is stored
+ * in sig->check_result, 'G' for a good signature, 'U' for a good signature
+ * from an untrusted signer, 'B' for a bad signature and 'N' for no signature
+ * at all.  This may allocate memory for sig->gpg_output, sig->gpg_status,
+ * sig->signer and sig->key.
  */
 extern void check_commit_signature(const struct commit* commit, struct signature *sig);
 
diff --git a/gpg-interface.h b/gpg-interface.h
index 2a536d9..7fd3021 100644
--- a/gpg-interface.h
+++ b/gpg-interface.h
@@ -4,7 +4,7 @@
 struct signature {
 	char *gpg_output;
 	char *gpg_status;
-	char check_result; /* 0 (not checked), N (checked but no further result), G (good) or B (bad) */
+	char check_result; /* 0 (not checked), N (checked but no further result), U (untrusted, good), G (good) or B (bad) */
 	char *signer;
 	char *key;
 };
diff --git a/t/lib-gpg/pubring.gpg b/t/lib-gpg/pubring.gpg
index 83855fa4e1c6c37afe550c17afa1e7971042ded5..1a3c2d487c2fda9169751a3068fa51e853a1e519 100644
GIT binary patch
delta 1212
zcmV;t1Vj6b3AYlkj0As~0SyFEOqNFh2mr~8{AU1PG9!Ku9w|}@vpZJPg*#s86v-*O
zhafj(DL&&lF<A0)`tvC$E@WHJ2r~0{0ZCh1kHo$b9ih^aD*~)oVvK&yC1(yi)6x_y
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z8C@tnj=CqkffSLs=a-5G+h;Y8bkw<s-iIgT{$f^j!)l`hmkz}$nZPxBoPmwU;zIH^
zLN~K=bO>hGBes9{Fcqzh%Wj2h^{ZjI01*KI0kkAVa%poQL}_zlZ*pX5VIVwYX>((5
za%4bdcwudDY-KKPWpqA?0XPH`0RjLb1p-k_mPY~`0|pBT2nPcK1{DYb2?`4Y76JnS
z0v-VZ7k~f?2@qikE`_%uafw)?2m1%-{uDP0Rs1|(F{OVhOSKoH$k!o)x3CO5Z^@El
zxGq=+xQGR&r@3$S<0@SUu@@UuxUH%pD3Q-D`?37Vg*xmo<%+KD)(U~k>XU^b+=70V
zFr?b3DvlFq^B*d%lz=lr!ch6nQbvcwWCD}n2DT3`r?RDkq=7r}qFvEh<dfApA7yR;
z8`OB;$TEKm@jkwG=8vlcKFd>rcM8+9eP66QueaUSz6NhphD3O@E(iX7T@2kxV(dXd
zxG_$z;qqdh<Np6*{J!OD7<b;8M6otxRi0UUN|OngZ4NdYbeU0hneiVEwY2h5xZ4z{
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zc)VOU|M7H$nU~Bd&(!9WlLk)V)&z>UY~vSc_rVFe1JAY7ThlG1IzE9z6>ly;9W<Ie
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z4BvmZ0TM||zk);(8@JN=fad9d4hK=Hf1{&&J5DP=<J9wW0IGZ_*p$xvH=WZu8h1r#
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zg^u)$-LG%(tX4KA^%L!j<@*Z_A!anKyx}t&F6RX0yYXc)&KtB~l*=nGq9`cf<aD`r
a9*zs=xM)EjeiKg!$s4>o369jT0ssS^s3f2O

delta 7
Ocmdlk)Wf-<hXnu&fC8TY

diff --git a/t/lib-gpg/random_seed b/t/lib-gpg/random_seed
index 8fed1339ed0a744e5663f4a5e6b6ac9bae3d8524..95d249f15fce980f0e8c1a8a18b085b3885708aa 100644
GIT binary patch
literal 600
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za}Z!boffEq^fn)n?c=IEnDpt59Lnc)aR*;8Z;k>gh_NW;ka;7Mt@v#sG(!Y9SSXWv
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mb-6m)4=6PVqdR>h+D!{<c#q1!T9b(}OW7hrrT@nJcBO(OGA4ll

literal 600
zcmV-e0;m1=h9nBV>1C6QsKJEiEJaD@Q3F8s5u<$E+<2(By)JAZSxviTsXg(wKC+O%
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z+V{Lt!_`eKGhyk5Edie{-^#n!TFlsfux*QBRZEh^4SVePPmb{BvF|>sKd2cYg@vKp
mVI8jcB1(k(tlt^Kr<{EMs>|b*d70nyVMQcc%xEnE(#Uq3d^-35

diff --git a/t/lib-gpg/secring.gpg b/t/lib-gpg/secring.gpg
index d831cd9eb3eee613d3c0e1a71093ae01ea7347e3..82dca8f80bf170fde5705862c3eeb9d994725042 100644
GIT binary patch
delta 2524
zcmV<22_yE^36>qO)dYW)1DFI+OqNFh2mr~8{AU1PG9!Ku9w|}@vpZJPg*#s86v-*O
zhafj(DL&&lF<A0)`tvC$E@WHJ2r~0{0ZCh1kHo$b9ih^aD*~)oVvK&yC1(yi)6x_y
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ml*=nGq9`cf<aD`r9*zs=xM)EjeiKg!$s4>o369jT0ssIhKC9;d

delta 7
OcmbOxdzEv;RTcmY+5;N^

diff --git a/t/lib-gpg/trustdb.gpg b/t/lib-gpg/trustdb.gpg
index abace962b8bf84be688a6f27e4ebd0ee7052f210..4879ae9a84650a93a4d15bd6560c5d1b89eb4c2f 100644
GIT binary patch
delta 133
zcmZqRy1*sEm|l?1%*@Ej$i%=9=re5@0|Nu&L_y(=>YJDu6*k{umSl_t3LyXw!<BtX
zhEkV><>GE>E=lCnYu&C?*vSl0pomb%%dj-dsEA)Mq*Svt$mH(j_twWhW_@KtD1fp6
DE~Fa=

delta 52
zcmcb>)xagdm|l?1%*@Ej$iTqhmVVlAqM`Uk^-atZ9rz~(oS3|U#hLd&3{VON0Ad;p
ADF6Tf

diff --git a/t/t7612-merge-verify-signatures.sh b/t/t7612-merge-verify-signatures.sh
index 31b67dd..47a4f80 100755
--- a/t/t7612-merge-verify-signatures.sh
+++ b/t/t7612-merge-verify-signatures.sh
@@ -27,6 +27,10 @@ test_expect_success GPG 'create signed commits' '
 	git hash-object -w -t commit forged >forged.commit &&
 	git checkout initial &&
 
+	git checkout -b side-untrusted &&
+	echo 3 >baz && git add baz &&
+	test_tick && git commit -SB7227189 -m "untrusted on side"
+
 	git checkout master
 '
 
@@ -40,6 +44,11 @@ test_expect_success GPG 'merge commit with bad signature with verification' '
 	grep "has a bad GPG signature" mergeerror
 '
 
+test_expect_success GPG 'merge  commit with untrusted signature with verification' '
+	test_must_fail git merge --ff-only --verify-signatures side-untrusted 2> mergeerror &&
+	grep "from an untrusted key" mergeerror
+'
+
 test_expect_success GPG 'merge signed commit with verification' '
 	git merge -v --ff-only --verify-signatures side-signed > mergeoutput &&
 	grep "has a good GPG signature" mergeoutput
-- 
1.8.1.5