SSL: Pinned public key hash support

2 files changed, 22 insertions, 8 deletions

diff --git a/docs/curl.1 b/docs/curl.1
index 11b95d4ef..afd4e8c35 100644
--- a/docs/curl.1
+++ b/docs/curl.1
@@ -544,9 +544,11 @@ OpenSSL-powered curl to make SSL-connections much more efficiently than using
 
 If this option is set, the default capath value will be ignored, and if it is
 used several times, the last one will be used.
-.IP "--pinnedpubkey <pinned public key>"
-(SSL) Tells curl to use the specified public key file to verify the peer. The
-file must contain a single public key in PEM or DER format.
+.IP "--pinnedpubkey <pinned public key (hashes)>"
+(SSL) Tells curl to use the specified public key file (or hashes) to verify the
+peer. This can be a path to a file which contains a single public key in PEM or
+DER format, or any number of base64 encoded sha256 hashes preceded by
+\'sha256//\' and seperated by \';\'
 
 When negotiating a TLS or SSL connection, the server sends a certificate
 indicating its identity. A public key is extracted from this certificate and
@@ -554,7 +556,8 @@ if it does not exactly match the public key provided to this option, curl will
 abort the connection before sending or receiving any data.
 
 Added in 7.39.0 for OpenSSL, GnuTLS and GSKit. Added in 7.43.0 for NSS and
-wolfSSL/CyaSSL. Other SSL backends not supported.
+wolfSSL/CyaSSL. sha256 support added in 7.44.0 for OpenSSL,
+GnuTLS, NSS and wolfSSL/CyaSSL. Other SSL backends not supported.
 
 If this option is used several times, the last one will be used.
 .IP "--cert-status"
diff --git a/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3 b/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3
index 94cad31f0..0d4357ab1 100644
--- a/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3
+++ b/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3
@@ -28,8 +28,10 @@ CURLOPT_PINNEDPUBLICKEY \- set pinned public key
 
 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PINNEDPUBLICKEY, char *pinnedpubkey);
 .SH DESCRIPTION
-Pass a pointer to a zero terminated string as parameter. The string should be
-the file name of your pinned public key. The format expected is "PEM" or "DER".
+Pass a pointer to a zero terminated string as parameter. The string can be the
+file name of your pinned public key. The file format expected is "PEM" or "DER".
+The string can also be any number of base64 encoded sha256 hashes preceded by
+"sha256//" and seperated by ";"
 
 When negotiating a TLS or SSL connection, the server sends a certificate
 indicating its identity. A public key is extracted from this certificate and
@@ -45,6 +47,9 @@ CURL *curl = curl_easy_init();
 if(curl) {
   curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
   curl_easy_setopt(curl, CURLOPT_PINNEDPUBLICKEY, "/etc/publickey.der");
+  /* OR
+  curl_easy_setopt(curl, CURLOPT_PINNEDPUBLICKEY, "sha256//YhKJKSzoTt2b5FP18fvpHo7fJYqQCjAa3HWY3tvRMwE=;sha256//t62CeU2tQiqkexU74Gxa2eg7fRbEgoChTociMee9wno=");
+  */
 
   /* Perform the request */
   curl_easy_perform(curl);
@@ -54,9 +59,14 @@ if(curl) {
 If you do not have the server's public key file you can extract it from the
 server's certificate.
 .nf
+# extract public key in pem format from certificate
 openssl x509 -in www.test.com.pem -pubkey -noout > www.test.com.pubkey.pem
+# convert public key from pem to der
+openssl asn1parse -noout -inform pem -in www.test.com.pubkey.pem -out www.test.com.pubkey.der
+# sha256 hash and base64 encode der to string for use
+openssl dgst -sha256 -binary www.test.com.pubkey.der | openssl base64
 .fi
-The public key is output in PEM format and contains a header, base64 data and a
+The public key in PEM format contains a header, base64 data and a
 footer:
 .nf
 -----BEGIN PUBLIC KEY-----
@@ -65,7 +75,8 @@ footer:
 .fi
 .SH AVAILABILITY
 Added in 7.39.0 for OpenSSL, GnuTLS and GSKit. Added in 7.43.0 for
-NSS and wolfSSL/CyaSSL. Other SSL backends not supported.
+NSS and wolfSSL/CyaSSL. sha256 support added in 7.44.0 for OpenSSL,
+GnuTLS, NSS and wolfSSL/CyaSSL. Other SSL backends not supported.
 .SH RETURN VALUE
 Returns CURLE_OK if TLS enabled, CURLE_UNKNOWN_OPTION if not, or
 CURLE_OUT_OF_MEMORY if there was insufficient heap space.