[PATCH 1/1] enable cgit to show gravatar for author, committer and tagger

[john at keeping.me.uk (John Keeping)]

On Wed, Nov 27, 2013 at 04:17:17PM +0100, Christian Hesse wrote:
> diff --git a/parsing.c b/parsing.c
> index 658621d..a8005f6 100644
> --- a/parsing.c
> +++ b/parsing.c
> @@ -8,6 +8,9 @@
>  
>  #include "cgit.h"
>  
> +/* we need md5 hashing algorithm to calculate Gravatar URL */
> +#include <openssl/md5.h>

We don't currently depend on OpenSSL, except via Git which can use
alternative SHA-1 implementations.

At the very least Debian will not distribute GPL'd packages
linked against OpenSSL [1].

[1] http://lintian.debian.org/tags/possible-gpl-code-linked-with-openssl.html

> +char * cgit_get_gravatar(const char * email) {
> +    	int n, length;
> +	MD5_CTX c;
> +	unsigned char digest[16];
> +	char hex[33];
> +	char * gravatar = malloc(67);
> +
> +	/* skip brackets! */
> +	email++;
> +	length = strlen(email) - 1;
> +
> +	MD5_Init(&c);
> +
> +	while (length > 0) {
> +		if (length > 512)
> +			MD5_Update(&c, email, 512);
> +		else
> +			MD5_Update(&c, email, length);
> +		length -= 512;
> +		email += 512;
> +	}
> +
> +	MD5_Final(digest, &c);

Would it be possible to extract everything from MD5_Init to MD5_Final to
a function that just computes the MD5 of a string?  That should make it
easier to add alternative implementations.

> +	for (n = 0; n < 16; ++n)
> +		snprintf(&(hex[n*2]), 16*2, "%02x", (unsigned int)digest[n]);
> +
> +	sprintf(gravatar, "http://www.gravatar.com/avatar/%s?s=", hex);
> +
> +	return gravatar;
> +}