MINOR: ssl: adds ssl_f_sha1 fetch to return frontend's certificate fingerprint

ssl_f_sha1 is a binary binary fetch used to returns the SHA-1 fingerprint of
the certificate presented by the frontend when the incoming connection was
made over an SSL/TLS transport layer. This can be used to know which
certificate was chosen using SNI.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 0cfb819..8c2c0b0 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -10434,6 +10434,11 @@
   incoming connection was made over an SSL/TLS transport layer. When used for
   an ACL, the value(s) to match against can be passed in hexadecimal form.
 
+ssl_f_sha1 : binary
+  Returns the SHA-1 fingerprint of the certificate presented by the frontend
+  when the incoming connection was made over an SSL/TLS transport layer. This
+  can be used to know which certificate was chosen using SNI.
+
 ssl_f_sig_alg : string
   Returns the name of the algorithm used to sign the certificate presented by
   the frontend when the incoming connection was made over an SSL/TLS transport
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index e88024d..19ede39 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -3435,6 +3435,7 @@
 	{ "ssl_f_sig_alg",          smp_fetch_ssl_x_sig_alg,      0,                   NULL,    SMP_T_STR,  SMP_USE_L5CLI },
 	{ "ssl_f_s_dn",             smp_fetch_ssl_x_s_dn,         ARG2(0,STR,SINT),    NULL,    SMP_T_STR,  SMP_USE_L5CLI },
 	{ "ssl_f_serial",           smp_fetch_ssl_x_serial,       0,                   NULL,    SMP_T_BIN,  SMP_USE_L5CLI },
+	{ "ssl_f_sha1",             smp_fetch_ssl_x_sha1,         0,                   NULL,    SMP_T_BIN,  SMP_USE_L5CLI },
 	{ "ssl_f_version",          smp_fetch_ssl_x_version,      0,                   NULL,    SMP_T_UINT, SMP_USE_L5CLI },
 	{ "ssl_fc",                 smp_fetch_ssl_fc,             0,                   NULL,    SMP_T_BOOL, SMP_USE_L5CLI },
 	{ "ssl_fc_alg_keysize",     smp_fetch_ssl_fc_alg_keysize, 0,                   NULL,    SMP_T_UINT, SMP_USE_L5CLI },