# DKIM : bad RSA signature

**URL:** <https://www.debian-fr.org/t/dkim-bad-rsa-signature/79553>\
**Category:** Support Debian\
**Created:** [Juillet 2, 2019, 4:01 UTC](https://www.debian-fr.org/t/dkim-bad-rsa-signature/79553 "2019-07-02T16:01:02Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![crustyourmind](https://www.debian-fr.org/user_avatar/www.debian-fr.org/crustyourmind/32/2955_2.png) [@crustyourmind](https://www.debian-fr.org/u/crustyourmind)\
**Post date:** [Juillet 2, 2019, 4:01 UTC](https://www.debian-fr.org/t/dkim-bad-rsa-signature/79553/1 "2019-07-02T16:01:03Z")

</div>

Bonjour sur un vps sous debian stable et managé via yunohost  
Probleme avec serveur de mail et DKIM

J’ai 2 noms de domaines  
Le premier me retourne avec [https://www.mail-tester.com](https://www.mail-tester.com) une note de 10/10

Le second pourtant configuré exactement de la même manière (c’est yonohost qui me fournit les infos), [https://www.mail-tester.com](https://www.mail-tester.com) me dit que j’ai un soucis avec mon DKIM  
[https://dkimvalidator.com](https://dkimvalidator.com) m’informe

```
DKIM Information:

DKIM Signature

Message contains this DKIM Signature:
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xxxxxxxxxxxxxxxxx.com;
	s=mail; t=1562082397; h=from:from:sender:reply-to:subject:subject:date:date:
	 message-id:message-id:to:to:cc:mime-version:mime-version:
	 content-type:content-type:
	 content-transfer-encoding:content-transfer-encoding:in-reply-to:
	 references; bh=g3zLYH4xKxcPrHOD18z9YfpQcnk/GaJedfustWU5uGs=;
	b=HNJiSpXoKr4oRP5yrjTzA4QCP9igyuXlFUuWudXiuZj+Foj0ZgdQ2fkVoNWeWEbRJ6gmpk
	iLj/JaZeLUsqa2PnTSJeiGzqtmF9EP9/nt1D2tfzknkFSCuFnS2v4zV3S4cAPhwZllv7CU
	QAsBTdm2NQ3UtMUlr7+cyQJO0UeYc7E=

Signature Information:
v= Version: 1
a= Algorithm: rsa-sha256
c= Method: relaxed/relaxed
d= Domain: xxxxxxxxxxxxxxxxxxxxx.com
s= Selector: mail
q= Protocol:        
bh= g3zLYH4xKxcPrHOD18z9YfpQcnk/GaJedfustWU5uGs=
h= Signed Headers: from:from:sender:reply-to:subject:subject:date:date:
	 message-id:message-id:to:to:cc:mime-version:mime-version:
	 content-type:content-type:
	 content-transfer-encoding:content-transfer-encoding:in-reply-to:
	 references
b= Data: HNJiSpXoKr4oRP5yrjTzA4QCP9igyuXlFUuWudXiuZj+Foj0ZgdQ2fkVoNWeWEbRJ6gmpk
	iLj/JaZeLUsqa2PnTSJeiGzqtmF9EP9/nt1D2tfzknkFSCuFnS2v4zV3S4cAPhwZllv7CU
	QAsBTdm2NQ3UtMUlr7+cyQJO0UeYc7E=
Public Key DNS Lookup

Building DNS Query for mail._domainkey.xxxxxxxxxxxxxxxxxxxxx.com
Retrieved this publickey from DNS: v=DKIM1; k=rsa; h=sha256; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDwkQIUTjkGj/XPM1rVavr1rJP6YRE9Xh0bbZ4Ko113VKKLrlD8HlVtzDdoO2W3YXecJ7ncExN9bOl8U8Af7iJUG2TYLJbWV2pG7U3JoIFS8wzLsZx1/+HuRKMbMujE/7eqkx4hdNNmi8hwtVK16JwTjIiT1K2IxtBGqd5Lrt5gvwIDAQAB
Validating Signature

result = fail
Details: bad RSA signature

```

J’ai vérifié j’ai pourtant la bonne clef d’identification, la config de la zone DNS est identique (mis à part le nom de domaine, bien sûr)

et

```
dig +short TXT mail._domainkey.monDomaine.ext
"v=DKIM1; k=rsa; h=sha256; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDwkQIUTjkGj/XPM1rVavr1rJP6YRE9Xh0bbZ4Ko113VKKLrlD8HlVtzDdoO2W3YXecJ7ncExN9bOl8U8Af7iJUG2TYLJbWV2pG7U3JoIFS8wzLsZx1/+HuRKMbMujE/7eqkx4hdNNmi8hwtVK16JwTjIiT1K2IxtBGqd5Lrt5gvwIDAQAB"

```

Des pistes ?

Merci d’avance

---

<div class="post-metadata">

**Author:** ![crustyourmind](https://www.debian-fr.org/user_avatar/www.debian-fr.org/crustyourmind/32/2955_2.png) [@crustyourmind](https://www.debian-fr.org/u/crustyourmind)\
**Post date:** [Juillet 2, 2019, 9:23 UTC](https://www.debian-fr.org/t/dkim-bad-rsa-signature/79553/2 "2019-07-02T21:23:28Z")

</div>

OK je suis un vrai ane, j’avais mis la clef de mon sous domaine et non de mon domaine…  
resolu