Implement VerifySignedData() for ECDSA, RSA PKCS#1 and RSA PSS.

net/data/verify_signed_data_unittest/rsa-pss-sha256-salt10.pem

Index: net/data/verify_signed_data_unittest/rsa-pss-sha256-salt10.pem
diff --git a/net/data/verify_signed_data_unittest/rsa-pss-sha256-salt10.pem b/net/data/verify_signed_data_unittest/rsa-pss-sha256-salt10.pem
new file mode 100644
index 0000000000000000000000000000000000000000..fc37f41d1feb43338e9c4dc0f13396bb4d60a3d7
--- /dev/null
+++ b/net/data/verify_signed_data_unittest/rsa-pss-sha256-salt10.pem
@@ -0,0 +1,65 @@
+The key, message, and signature come from:
+http://csrc.nist.gov/groups/STM/cavp/documents/dss/186-2rsatestvectors.zip (SigVerPSS_186-3.rsp)
+
+(The algorithm DER was synthesized to match, and the signature wrapped in a BIT STRING).
+
+It uses an RSA key with modulus length of 1024 bits, PSS padding,
+SHA-256 as the digest, MGF1 with SHA-256, and salt length of 10.
+
+
+
+-----BEGIN PUBLIC KEY-----
+MIGdMA0GCSqGSIb3DQEBAQUAA4GLADCBhwKBgQC+SZtefwbIP6ApPjFGXI62tYr5ILrlKntbm/6
+3qnLbEmQRLrP9Qx0xoqflCUFWaSlJSg6JHtVhORi0tRsNH7l3g7Jqz30POEz7NfTSgk9d04BiOi
+a/GAtjlhxhnc2yDK5AbyL24nbICjcllJDP63LBpxqE8YRtMwh3uj4xAeycewIBEQ==
+-----END PUBLIC KEY-----
+
+$ openssl asn1parse -i < [PUBLIC KEY]
+    0:d=0  hl=3 l= 157 cons: SEQUENCE          
+    3:d=1  hl=2 l=  13 cons:  SEQUENCE          
+    5:d=2  hl=2 l=   9 prim:   OBJECT            :rsaEncryption
+   16:d=2  hl=2 l=   0 prim:   NULL              
+   18:d=1  hl=3 l= 139 prim:  BIT STRING        
+
+
+
+-----BEGIN ALGORITHM-----
+MEEGCSqGSIb3DQEBCjA0oA8wDQYJYIZIAWUDBAIBBQChHDAaBgkqhkiG9w0BAQgwDQYJYIZIAWU
+DBAIBBQCiAwIBCg==
+-----END ALGORITHM-----
+
+$ openssl asn1parse -i < [ALGORITHM]
+    0:d=0  hl=2 l=  65 cons: SEQUENCE          
+    2:d=1  hl=2 l=   9 prim:  OBJECT            :rsassaPss
+   13:d=1  hl=2 l=  52 cons:  SEQUENCE          
+   15:d=2  hl=2 l=  15 cons:   cont [ 0 ]        
+   17:d=3  hl=2 l=  13 cons:    SEQUENCE          
+   19:d=4  hl=2 l=   9 prim:     OBJECT            :sha256
+   30:d=4  hl=2 l=   0 prim:     NULL              
+   32:d=2  hl=2 l=  28 cons:   cont [ 1 ]        
+   34:d=3  hl=2 l=  26 cons:    SEQUENCE          
+   36:d=4  hl=2 l=   9 prim:     OBJECT            :mgf1
+   47:d=4  hl=2 l=  13 cons:     SEQUENCE          
+   49:d=5  hl=2 l=   9 prim:      OBJECT            :sha256
+   60:d=5  hl=2 l=   0 prim:      NULL              
+   62:d=2  hl=2 l=   3 cons:   cont [ 2 ]        
+   64:d=3  hl=2 l=   1 prim:    INTEGER           :0A
+
+
+
+-----BEGIN DATA-----
+x/UnD8pyX5vRn1GajXzKPMXAeQJAKfO65RD5sCFA/iOJCOT2wY8HqJxofIaEZpsfHbK6+SUaPIK
+frMtJMIThbsnijViGgHSl1iIWZ91uUo0W/iyfPbTPr2xNzoyEOa84zqqqnOLsrnvI9KWlXjv5bf
+nNV1xPnLMnlRuM3+QIcWg=
+-----END DATA-----
+
+
+
+-----BEGIN SIGNATURE-----
+A4GBABHhafL9QLB2Qbl2iiqxmWX7bCfxD88DI/zG0S608cBrMw3aoepQRAevop3p6+A3T+nR59D
+/vV/Bzzo0RuQUVBXSqyT3ibNGTFxDola7wdaSz38EgB2sW7QBpKA6t9VyioYMGeGk3Hl8pULIID
+zsLmAesMUfVn8u2gIrC5693u76
+-----END SIGNATURE-----
+
+$ openssl asn1parse -i < [SIGNATURE]
+    0:d=0  hl=3 l= 129 prim: BIT STRING