Can attackers change the public key of certificate during the SSL handshakeIs Spoofing a CA signed certificate possible?Client Certificate in SSL HandShake insecure?Can attackers steal SSL certificate from server and use it for MITM attacks?Does mutual authentication have any impact on MiTM possibilities?How the process of SSL handshake works?Server authentication during the SSL handshakeSpecific clarification on how https server public key is trustedWhat happens when attacker disrupts the ssl handshake?Can a man in the middle hear half the HTTPS conversationPossibility of Man in the Middle attack in SSL Protocol during initial Handshake
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Can attackers change the public key of certificate during the SSL handshake
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Can attackers change the public key of certificate during the SSL handshake
Is Spoofing a CA signed certificate possible?Client Certificate in SSL HandShake insecure?Can attackers steal SSL certificate from server and use it for MITM attacks?Does mutual authentication have any impact on MiTM possibilities?How the process of SSL handshake works?Server authentication during the SSL handshakeSpecific clarification on how https server public key is trustedWhat happens when attacker disrupts the ssl handshake?Can a man in the middle hear half the HTTPS conversationPossibility of Man in the Middle attack in SSL Protocol during initial Handshake
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The communication is not encrypted during the SSL handshake. If an attacker conducts a man in the middle attack between server and client to capture the certificate, and change the public key in the certificate and send it to client, then the digital signature is same, all the properties except public key are same.
So how can a browser understand the difference? If browser validates it, the attacker can use his/her own key pair and doesn't need the private key of the server.
tls man-in-the-middle digital-signature handshake
edited 5 hours ago
schroeder♦
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add a comment |
The communication is not encrypted during the SSL handshake. If an attacker conducts a man in the middle attack between server and client to capture the certificate, and change the public key in the certificate and send it to client, then the digital signature is same, all the properties except public key are same.
So how can a browser understand the difference? If browser validates it, the attacker can use his/her own key pair and doesn't need the private key of the server.
tls man-in-the-middle digital-signature handshake
edited 5 hours ago
schroeder♦
84.3k34 gold badges188 silver badges226 bronze badges
asked 8 hours ago
GreyGrey
252 bronze badges
add a comment |
The communication is not encrypted during the SSL handshake. If an attacker conducts a man in the middle attack between server and client to capture the certificate, and change the public key in the certificate and send it to client, then the digital signature is same, all the properties except public key are same.
So how can a browser understand the difference? If browser validates it, the attacker can use his/her own key pair and doesn't need the private key of the server.
tls man-in-the-middle digital-signature handshake
edited 5 hours ago
schroeder♦
84.3k34 gold badges188 silver badges226 bronze badges
asked 8 hours ago
GreyGrey
252 bronze badges
The communication is not encrypted during the SSL handshake. If an attacker conducts a man in the middle attack between server and client to capture the certificate, and change the public key in the certificate and send it to client, then the digital signature is same, all the properties except public key are same.
So how can a browser understand the difference? If browser validates it, the attacker can use his/her own key pair and doesn't need the private key of the server.
tls man-in-the-middle digital-signature handshake
tls man-in-the-middle digital-signature handshake
edited 5 hours ago
schroeder♦
84.3k34 gold badges188 silver badges226 bronze badges
asked 8 hours ago
GreyGrey
252 bronze badges
edited 5 hours ago
schroeder♦
84.3k34 gold badges188 silver badges226 bronze badges
asked 8 hours ago
GreyGrey
252 bronze badges
edited 5 hours ago
schroeder♦
84.3k34 gold badges188 silver badges226 bronze badges
edited 5 hours ago
schroeder♦
84.3k34 gold badges188 silver badges226 bronze badges
edited 5 hours ago
schroeder♦
84.3k34 gold badges188 silver badges226 bronze badges
84.3k34 gold badges188 silver badges226 bronze badges
asked 8 hours ago
GreyGrey
252 bronze badges
asked 8 hours ago
GreyGrey
252 bronze badges
asked 8 hours ago
GreyGrey
252 bronze badges
252 bronze badges
add a comment |
add a comment |
2 Answers
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At the end of the TLS negotiation (the "Finished" message), the client and the server take a hash of the entire conversation they've had so far, and they compare it. If it differs - as it would if someone performed a MitM attack on the certificate - then the connection is dropped.
To quote RFC 5246:
The Finished message is the first one protected with the just
negotiated algorithms, keys, and secrets. Recipients of Finished
messages MUST verify that the contents are correct. Once a side
has sent its Finished message and received and validated the
Finished message from its peer, it may begin to send and receive
application data over the connection.
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
add a comment |
... change the public key in the certificate and send it to client. Digital signature is same, all the properties except public key are same. So how can browser understand the difference?
The browser checks that the signature of the certificates fits the certificate. Since the public key is included in the signature and the public key is changed, the signature no longer fits the certificate. Therefore the validation will fail.
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
add a comment |
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2 Answers
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2 Answers
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At the end of the TLS negotiation (the "Finished" message), the client and the server take a hash of the entire conversation they've had so far, and they compare it. If it differs - as it would if someone performed a MitM attack on the certificate - then the connection is dropped.
To quote RFC 5246:
The Finished message is the first one protected with the just
negotiated algorithms, keys, and secrets. Recipients of Finished
messages MUST verify that the contents are correct. Once a side
has sent its Finished message and received and validated the
Finished message from its peer, it may begin to send and receive
application data over the connection.
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
add a comment |
At the end of the TLS negotiation (the "Finished" message), the client and the server take a hash of the entire conversation they've had so far, and they compare it. If it differs - as it would if someone performed a MitM attack on the certificate - then the connection is dropped.
To quote RFC 5246:
The Finished message is the first one protected with the just
negotiated algorithms, keys, and secrets. Recipients of Finished
messages MUST verify that the contents are correct. Once a side
has sent its Finished message and received and validated the
Finished message from its peer, it may begin to send and receive
application data over the connection.
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
add a comment |
At the end of the TLS negotiation (the "Finished" message), the client and the server take a hash of the entire conversation they've had so far, and they compare it. If it differs - as it would if someone performed a MitM attack on the certificate - then the connection is dropped.
To quote RFC 5246:
The Finished message is the first one protected with the just
negotiated algorithms, keys, and secrets. Recipients of Finished
messages MUST verify that the contents are correct. Once a side
has sent its Finished message and received and validated the
Finished message from its peer, it may begin to send and receive
application data over the connection.
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
At the end of the TLS negotiation (the "Finished" message), the client and the server take a hash of the entire conversation they've had so far, and they compare it. If it differs - as it would if someone performed a MitM attack on the certificate - then the connection is dropped.
To quote RFC 5246:
The Finished message is the first one protected with the just
negotiated algorithms, keys, and secrets. Recipients of Finished
messages MUST verify that the contents are correct. Once a side
has sent its Finished message and received and validated the
Finished message from its peer, it may begin to send and receive
application data over the connection.
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
answered 8 hours ago
gowenfawrgowenfawr
57k12 gold badges124 silver badges168 bronze badges
57k12 gold badges124 silver badges168 bronze badges
add a comment |
add a comment |
... change the public key in the certificate and send it to client. Digital signature is same, all the properties except public key are same. So how can browser understand the difference?
The browser checks that the signature of the certificates fits the certificate. Since the public key is included in the signature and the public key is changed, the signature no longer fits the certificate. Therefore the validation will fail.
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
add a comment |
... change the public key in the certificate and send it to client. Digital signature is same, all the properties except public key are same. So how can browser understand the difference?
The browser checks that the signature of the certificates fits the certificate. Since the public key is included in the signature and the public key is changed, the signature no longer fits the certificate. Therefore the validation will fail.
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
add a comment |
... change the public key in the certificate and send it to client. Digital signature is same, all the properties except public key are same. So how can browser understand the difference?
The browser checks that the signature of the certificates fits the certificate. Since the public key is included in the signature and the public key is changed, the signature no longer fits the certificate. Therefore the validation will fail.
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
... change the public key in the certificate and send it to client. Digital signature is same, all the properties except public key are same. So how can browser understand the difference?
The browser checks that the signature of the certificates fits the certificate. Since the public key is included in the signature and the public key is changed, the signature no longer fits the certificate. Therefore the validation will fail.
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
answered 6 hours ago
Steffen UllrichSteffen Ullrich
127k17 gold badges223 silver badges290 bronze badges
127k17 gold badges223 silver badges290 bronze badges
add a comment |
add a comment |
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