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

net/data/verify_signed_data_unittest/rsa-pss-sha256-mgf1-sha512-salt33.pem

Index: net/data/verify_signed_data_unittest/rsa-pss-sha256-mgf1-sha512-salt33.pem
diff --git a/net/data/verify_signed_data_unittest/rsa-pss-sha256-mgf1-sha512-salt33.pem b/net/data/verify_signed_data_unittest/rsa-pss-sha256-mgf1-sha512-salt33.pem
new file mode 100644
index 0000000000000000000000000000000000000000..f3b9dcb6fe63f0dd9dc689cfcf843b963c7a4969
--- /dev/null
+++ b/net/data/verify_signed_data_unittest/rsa-pss-sha256-mgf1-sha512-salt33.pem
@@ -0,0 +1,67 @@
+This test exercises using a different hash function parameter to the mask gen
+function (SHA-256 for the hash, but SHA-512 for the MGF1 hash).
+
+This test data was constructed manually by calling signing functions from
+OpenSSL code.
+
+It constructs an RSASSA-PSS signature using:
+  * Key with modulus 1024 bit
+  * Salt length 33 bytes
+  * Digest function of SHA-256
+  * Mask gen function of MGF1 with SHA-512
+
+
+
+-----BEGIN PUBLIC KEY-----
+MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQClbkoOcBAXWJpRh9x+qEHRVvLsDjatUqRN/rH
+mH3rZkdjFEFb/7bFitMDyg6EqiKOU3/Umq3KRy7MHzqv84LHf1c2VCAltWyuLbfXWce9jd8CSHL
+I8Jwpw4lmOb/idGfEFrMLT8Ms18pKA4Thrb2TE7yLh4fINDOjP+yJJvZohNwIDAQAB
+-----END PUBLIC KEY-----
+
+$ openssl asn1parse -i < [PUBLIC KEY]
+    0:d=0  hl=3 l= 159 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= 141 prim:  BIT STRING        
+
+
+
+-----BEGIN ALGORITHM-----
+MEEGCSqGSIb3DQEBCjA0oA8wDQYJYIZIAWUDBAIBBQChHDAaBgkqhkiG9w0BAQgwDQYJYIZIAWU
+DBAIDBQCiAwIBIQ==
+-----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            :sha512
+   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           :21
+
+
+
+-----BEGIN DATA-----
+VGVzdCBtZXNzYWdlIHRvIGJlIHNpZ25lZC4uLg==
+-----END DATA-----
+
+
+
+-----BEGIN SIGNATURE-----
+A4GBAFob0HSC5uuTqKu4J/lj+5bDa+Hhij4H3klWnvt6Yc+wwPza7/UC4lgGGyvZqD32RUEdt7v
+Z14qqYNk53b5aj4C2gBMvLzV7Pay4mmQM4DSWa5JHMxTILqE3DDqihrbMcBw2q3XAsLcjeqLWQ9
+yp8tfnV21h98qsCLtErrxZWHRr
+-----END SIGNATURE-----
+
+$ openssl asn1parse -i < [SIGNATURE]
+    0:d=0  hl=3 l= 129 prim: BIT STRING